зеркало из https://github.com/github/putty.git
2713 строки
80 KiB
C
2713 строки
80 KiB
C
/*
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* Code for PuTTY to import and export private key files in other
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* SSH clients' formats.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <assert.h>
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#include <ctype.h>
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#include "putty.h"
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#include "ssh.h"
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#include "misc.h"
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int openssh_pem_encrypted(const Filename *filename);
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int openssh_new_encrypted(const Filename *filename);
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struct ssh2_userkey *openssh_pem_read(const Filename *filename,
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char *passphrase,
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const char **errmsg_p);
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struct ssh2_userkey *openssh_new_read(const Filename *filename,
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char *passphrase,
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const char **errmsg_p);
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int openssh_auto_write(const Filename *filename, struct ssh2_userkey *key,
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char *passphrase);
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int openssh_pem_write(const Filename *filename, struct ssh2_userkey *key,
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char *passphrase);
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int openssh_new_write(const Filename *filename, struct ssh2_userkey *key,
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char *passphrase);
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int sshcom_encrypted(const Filename *filename, char **comment);
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struct ssh2_userkey *sshcom_read(const Filename *filename, char *passphrase,
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const char **errmsg_p);
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int sshcom_write(const Filename *filename, struct ssh2_userkey *key,
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char *passphrase);
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/*
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* Given a key type, determine whether we know how to import it.
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*/
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int import_possible(int type)
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{
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if (type == SSH_KEYTYPE_OPENSSH_PEM)
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return 1;
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if (type == SSH_KEYTYPE_OPENSSH_NEW)
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return 1;
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if (type == SSH_KEYTYPE_SSHCOM)
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return 1;
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return 0;
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}
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/*
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* Given a key type, determine what native key type
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* (SSH_KEYTYPE_SSH1 or SSH_KEYTYPE_SSH2) it will come out as once
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* we've imported it.
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*/
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int import_target_type(int type)
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{
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/*
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* There are no known foreign SSH-1 key formats.
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*/
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return SSH_KEYTYPE_SSH2;
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}
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/*
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* Determine whether a foreign key is encrypted.
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*/
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int import_encrypted(const Filename *filename, int type, char **comment)
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{
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if (type == SSH_KEYTYPE_OPENSSH_PEM) {
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/* OpenSSH PEM format doesn't contain a key comment at all */
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*comment = dupstr(filename_to_str(filename));
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return openssh_pem_encrypted(filename);
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} else if (type == SSH_KEYTYPE_OPENSSH_NEW) {
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/* OpenSSH new format does, but it's inside the encrypted
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* section for some reason */
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*comment = dupstr(filename_to_str(filename));
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return openssh_new_encrypted(filename);
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} else if (type == SSH_KEYTYPE_SSHCOM) {
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return sshcom_encrypted(filename, comment);
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}
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return 0;
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}
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/*
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* Import an SSH-1 key.
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*/
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int import_ssh1(const Filename *filename, int type,
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struct RSAKey *key, char *passphrase, const char **errmsg_p)
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{
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return 0;
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}
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/*
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* Import an SSH-2 key.
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*/
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struct ssh2_userkey *import_ssh2(const Filename *filename, int type,
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char *passphrase, const char **errmsg_p)
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{
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if (type == SSH_KEYTYPE_OPENSSH_PEM)
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return openssh_pem_read(filename, passphrase, errmsg_p);
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else if (type == SSH_KEYTYPE_OPENSSH_NEW)
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return openssh_new_read(filename, passphrase, errmsg_p);
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if (type == SSH_KEYTYPE_SSHCOM)
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return sshcom_read(filename, passphrase, errmsg_p);
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return NULL;
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}
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/*
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* Export an SSH-1 key.
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*/
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int export_ssh1(const Filename *filename, int type, struct RSAKey *key,
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char *passphrase)
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{
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return 0;
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}
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/*
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* Export an SSH-2 key.
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*/
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int export_ssh2(const Filename *filename, int type,
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struct ssh2_userkey *key, char *passphrase)
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{
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if (type == SSH_KEYTYPE_OPENSSH_AUTO)
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return openssh_auto_write(filename, key, passphrase);
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if (type == SSH_KEYTYPE_OPENSSH_NEW)
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return openssh_new_write(filename, key, passphrase);
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if (type == SSH_KEYTYPE_SSHCOM)
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return sshcom_write(filename, key, passphrase);
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return 0;
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}
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/*
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* Strip trailing CRs and LFs at the end of a line of text.
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*/
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void strip_crlf(char *str)
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{
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char *p = str + strlen(str);
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while (p > str && (p[-1] == '\r' || p[-1] == '\n'))
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*--p = '\0';
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}
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/* ----------------------------------------------------------------------
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* Helper routines. (The base64 ones are defined in sshpubk.c.)
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*/
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#define isbase64(c) ( ((c) >= 'A' && (c) <= 'Z') || \
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((c) >= 'a' && (c) <= 'z') || \
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((c) >= '0' && (c) <= '9') || \
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(c) == '+' || (c) == '/' || (c) == '=' \
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)
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/*
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* Read an ASN.1/BER identifier and length pair.
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*
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* Flags are a combination of the #defines listed below.
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*
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* Returns -1 if unsuccessful; otherwise returns the number of
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* bytes used out of the source data.
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*/
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/* ASN.1 tag classes. */
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#define ASN1_CLASS_UNIVERSAL (0 << 6)
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#define ASN1_CLASS_APPLICATION (1 << 6)
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#define ASN1_CLASS_CONTEXT_SPECIFIC (2 << 6)
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#define ASN1_CLASS_PRIVATE (3 << 6)
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#define ASN1_CLASS_MASK (3 << 6)
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/* Primitive versus constructed bit. */
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#define ASN1_CONSTRUCTED (1 << 5)
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static int ber_read_id_len(void *source, int sourcelen,
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int *id, int *length, int *flags)
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{
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unsigned char *p = (unsigned char *) source;
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if (sourcelen == 0)
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return -1;
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*flags = (*p & 0xE0);
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if ((*p & 0x1F) == 0x1F) {
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*id = 0;
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while (*p & 0x80) {
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p++, sourcelen--;
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if (sourcelen == 0)
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return -1;
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*id = (*id << 7) | (*p & 0x7F);
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}
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p++, sourcelen--;
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} else {
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*id = *p & 0x1F;
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p++, sourcelen--;
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}
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if (sourcelen == 0)
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return -1;
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if (*p & 0x80) {
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unsigned len;
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int n = *p & 0x7F;
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p++, sourcelen--;
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if (sourcelen < n)
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return -1;
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len = 0;
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while (n--)
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len = (len << 8) | (*p++);
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sourcelen -= n;
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*length = toint(len);
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} else {
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*length = *p;
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p++, sourcelen--;
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}
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return p - (unsigned char *) source;
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}
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/*
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* Write an ASN.1/BER identifier and length pair. Returns the
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* number of bytes consumed. Assumes dest contains enough space.
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* Will avoid writing anything if dest is NULL, but still return
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* amount of space required.
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*/
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static int ber_write_id_len(void *dest, int id, int length, int flags)
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{
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unsigned char *d = (unsigned char *)dest;
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int len = 0;
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if (id <= 30) {
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/*
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* Identifier is one byte.
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*/
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len++;
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if (d) *d++ = id | flags;
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} else {
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int n;
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/*
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* Identifier is multiple bytes: the first byte is 11111
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* plus the flags, and subsequent bytes encode the value of
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* the identifier, 7 bits at a time, with the top bit of
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* each byte 1 except the last one which is 0.
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*/
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len++;
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if (d) *d++ = 0x1F | flags;
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for (n = 1; (id >> (7*n)) > 0; n++)
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continue; /* count the bytes */
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while (n--) {
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len++;
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if (d) *d++ = (n ? 0x80 : 0) | ((id >> (7*n)) & 0x7F);
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}
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}
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if (length < 128) {
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/*
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* Length is one byte.
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*/
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len++;
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if (d) *d++ = length;
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} else {
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int n;
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/*
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* Length is multiple bytes. The first is 0x80 plus the
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* number of subsequent bytes, and the subsequent bytes
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* encode the actual length.
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*/
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for (n = 1; (length >> (8*n)) > 0; n++)
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continue; /* count the bytes */
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len++;
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if (d) *d++ = 0x80 | n;
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while (n--) {
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len++;
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if (d) *d++ = (length >> (8*n)) & 0xFF;
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}
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}
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return len;
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}
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static int put_uint32(void *target, unsigned val)
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{
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unsigned char *d = (unsigned char *)target;
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PUT_32BIT(d, val);
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return 4;
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}
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static int put_string(void *target, const void *data, int len)
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{
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unsigned char *d = (unsigned char *)target;
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PUT_32BIT(d, len);
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memcpy(d+4, data, len);
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return len+4;
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}
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static int put_string_z(void *target, const char *string)
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{
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return put_string(target, string, strlen(string));
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}
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static int put_mp(void *target, void *data, int len)
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{
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unsigned char *d = (unsigned char *)target;
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unsigned char *i = (unsigned char *)data;
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if (*i & 0x80) {
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PUT_32BIT(d, len+1);
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d[4] = 0;
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memcpy(d+5, data, len);
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return len+5;
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} else {
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PUT_32BIT(d, len);
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memcpy(d+4, data, len);
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return len+4;
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}
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}
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/* Simple structure to point to an mp-int within a blob. */
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struct mpint_pos { void *start; int bytes; };
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static int ssh2_read_mpint(void *data, int len, struct mpint_pos *ret)
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{
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int bytes;
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unsigned char *d = (unsigned char *) data;
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if (len < 4)
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goto error;
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bytes = toint(GET_32BIT(d));
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if (bytes < 0 || len-4 < bytes)
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goto error;
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ret->start = d + 4;
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ret->bytes = bytes;
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return bytes+4;
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error:
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ret->start = NULL;
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ret->bytes = -1;
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return len; /* ensure further calls fail as well */
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}
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/* ----------------------------------------------------------------------
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* Code to read and write OpenSSH private keys, in the old-style PEM
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* format.
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*/
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typedef enum {
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OP_DSA, OP_RSA, OP_ECDSA
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} openssh_pem_keytype;
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typedef enum {
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OP_E_3DES, OP_E_AES
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} openssh_pem_enc;
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struct openssh_pem_key {
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openssh_pem_keytype keytype;
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int encrypted;
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openssh_pem_enc encryption;
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char iv[32];
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unsigned char *keyblob;
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int keyblob_len, keyblob_size;
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};
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static struct openssh_pem_key *load_openssh_pem_key(const Filename *filename,
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const char **errmsg_p)
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{
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struct openssh_pem_key *ret;
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FILE *fp = NULL;
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char *line = NULL;
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const char *errmsg;
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char *p;
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int headers_done;
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char base64_bit[4];
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int base64_chars = 0;
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ret = snew(struct openssh_pem_key);
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ret->keyblob = NULL;
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ret->keyblob_len = ret->keyblob_size = 0;
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fp = f_open(filename, "r", FALSE);
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if (!fp) {
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errmsg = "unable to open key file";
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goto error;
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}
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if (!(line = fgetline(fp))) {
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errmsg = "unexpected end of file";
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goto error;
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}
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strip_crlf(line);
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if (!strstartswith(line, "-----BEGIN ") ||
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!strendswith(line, "PRIVATE KEY-----")) {
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errmsg = "file does not begin with OpenSSH key header";
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goto error;
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}
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/*
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* Parse the BEGIN line. For old-format keys, this tells us the
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* type of the key; for new-format keys, all it tells us is the
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* format, and we'll find out the key type once we parse the
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* base64.
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*/
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if (!strcmp(line, "-----BEGIN RSA PRIVATE KEY-----")) {
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ret->keytype = OP_RSA;
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} else if (!strcmp(line, "-----BEGIN DSA PRIVATE KEY-----")) {
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ret->keytype = OP_DSA;
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} else if (!strcmp(line, "-----BEGIN EC PRIVATE KEY-----")) {
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ret->keytype = OP_ECDSA;
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} else if (!strcmp(line, "-----BEGIN OPENSSH PRIVATE KEY-----")) {
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errmsg = "this is a new-style OpenSSH key";
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goto error;
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} else {
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errmsg = "unrecognised key type";
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goto error;
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}
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smemclr(line, strlen(line));
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sfree(line);
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line = NULL;
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ret->encrypted = FALSE;
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memset(ret->iv, 0, sizeof(ret->iv));
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headers_done = 0;
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while (1) {
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if (!(line = fgetline(fp))) {
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errmsg = "unexpected end of file";
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goto error;
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}
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strip_crlf(line);
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if (strstartswith(line, "-----END ") &&
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strendswith(line, "PRIVATE KEY-----")) {
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sfree(line);
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line = NULL;
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break; /* done */
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}
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if ((p = strchr(line, ':')) != NULL) {
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if (headers_done) {
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errmsg = "header found in body of key data";
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goto error;
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}
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*p++ = '\0';
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while (*p && isspace((unsigned char)*p)) p++;
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if (!strcmp(line, "Proc-Type")) {
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if (p[0] != '4' || p[1] != ',') {
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errmsg = "Proc-Type is not 4 (only 4 is supported)";
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goto error;
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}
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p += 2;
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if (!strcmp(p, "ENCRYPTED"))
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ret->encrypted = TRUE;
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} else if (!strcmp(line, "DEK-Info")) {
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int i, ivlen;
|
|
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if (!strncmp(p, "DES-EDE3-CBC,", 13)) {
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ret->encryption = OP_E_3DES;
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ivlen = 8;
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} else if (!strncmp(p, "AES-128-CBC,", 12)) {
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ret->encryption = OP_E_AES;
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ivlen = 16;
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} else {
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errmsg = "unsupported cipher";
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goto error;
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}
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p = strchr(p, ',') + 1;/* always non-NULL, by above checks */
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for (i = 0; i < ivlen; i++) {
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unsigned j;
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if (1 != sscanf(p, "%2x", &j)) {
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errmsg = "expected more iv data in DEK-Info";
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goto error;
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}
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ret->iv[i] = j;
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p += 2;
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}
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if (*p) {
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errmsg = "more iv data than expected in DEK-Info";
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goto error;
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}
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}
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} else {
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headers_done = 1;
|
|
|
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p = line;
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while (isbase64(*p)) {
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base64_bit[base64_chars++] = *p;
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|
if (base64_chars == 4) {
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|
unsigned char out[3];
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int len;
|
|
|
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base64_chars = 0;
|
|
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len = base64_decode_atom(base64_bit, out);
|
|
|
|
if (len <= 0) {
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errmsg = "invalid base64 encoding";
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goto error;
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|
}
|
|
|
|
if (ret->keyblob_len + len > ret->keyblob_size) {
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|
ret->keyblob_size = ret->keyblob_len + len + 256;
|
|
ret->keyblob = sresize(ret->keyblob, ret->keyblob_size,
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|
unsigned char);
|
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}
|
|
|
|
memcpy(ret->keyblob + ret->keyblob_len, out, len);
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ret->keyblob_len += len;
|
|
|
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smemclr(out, sizeof(out));
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}
|
|
|
|
p++;
|
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}
|
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}
|
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smemclr(line, strlen(line));
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sfree(line);
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|
line = NULL;
|
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}
|
|
|
|
fclose(fp);
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|
fp = NULL;
|
|
|
|
if (ret->keyblob_len == 0 || !ret->keyblob) {
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|
errmsg = "key body not present";
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|
goto error;
|
|
}
|
|
|
|
if (ret->encrypted && ret->keyblob_len % 8 != 0) {
|
|
errmsg = "encrypted key blob is not a multiple of "
|
|
"cipher block size";
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|
goto error;
|
|
}
|
|
|
|
smemclr(base64_bit, sizeof(base64_bit));
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|
if (errmsg_p) *errmsg_p = NULL;
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return ret;
|
|
|
|
error:
|
|
if (line) {
|
|
smemclr(line, strlen(line));
|
|
sfree(line);
|
|
line = NULL;
|
|
}
|
|
smemclr(base64_bit, sizeof(base64_bit));
|
|
if (ret) {
|
|
if (ret->keyblob) {
|
|
smemclr(ret->keyblob, ret->keyblob_size);
|
|
sfree(ret->keyblob);
|
|
}
|
|
smemclr(ret, sizeof(*ret));
|
|
sfree(ret);
|
|
}
|
|
if (errmsg_p) *errmsg_p = errmsg;
|
|
if (fp) fclose(fp);
|
|
return NULL;
|
|
}
|
|
|
|
int openssh_pem_encrypted(const Filename *filename)
|
|
{
|
|
struct openssh_pem_key *key = load_openssh_pem_key(filename, NULL);
|
|
int ret;
|
|
|
|
if (!key)
|
|
return 0;
|
|
ret = key->encrypted;
|
|
smemclr(key->keyblob, key->keyblob_size);
|
|
sfree(key->keyblob);
|
|
smemclr(key, sizeof(*key));
|
|
sfree(key);
|
|
return ret;
|
|
}
|
|
|
|
struct ssh2_userkey *openssh_pem_read(const Filename *filename,
|
|
char *passphrase,
|
|
const char **errmsg_p)
|
|
{
|
|
struct openssh_pem_key *key = load_openssh_pem_key(filename, errmsg_p);
|
|
struct ssh2_userkey *retkey;
|
|
unsigned char *p, *q;
|
|
int ret, id, len, flags;
|
|
int i, num_integers;
|
|
struct ssh2_userkey *retval = NULL;
|
|
const char *errmsg;
|
|
unsigned char *blob;
|
|
int blobsize = 0, blobptr, privptr;
|
|
char *modptr = NULL;
|
|
int modlen = 0;
|
|
|
|
blob = NULL;
|
|
|
|
if (!key)
|
|
return NULL;
|
|
|
|
if (key->encrypted) {
|
|
/*
|
|
* Derive encryption key from passphrase and iv/salt:
|
|
*
|
|
* - let block A equal MD5(passphrase || iv)
|
|
* - let block B equal MD5(A || passphrase || iv)
|
|
* - block C would be MD5(B || passphrase || iv) and so on
|
|
* - encryption key is the first N bytes of A || B
|
|
*
|
|
* (Note that only 8 bytes of the iv are used for key
|
|
* derivation, even when the key is encrypted with AES and
|
|
* hence there are 16 bytes available.)
|
|
*/
|
|
struct MD5Context md5c;
|
|
unsigned char keybuf[32];
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
|
|
MD5Update(&md5c, (unsigned char *)key->iv, 8);
|
|
MD5Final(keybuf, &md5c);
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, keybuf, 16);
|
|
MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
|
|
MD5Update(&md5c, (unsigned char *)key->iv, 8);
|
|
MD5Final(keybuf+16, &md5c);
|
|
|
|
/*
|
|
* Now decrypt the key blob.
|
|
*/
|
|
if (key->encryption == OP_E_3DES)
|
|
des3_decrypt_pubkey_ossh(keybuf, (unsigned char *)key->iv,
|
|
key->keyblob, key->keyblob_len);
|
|
else {
|
|
void *ctx;
|
|
assert(key->encryption == OP_E_AES);
|
|
ctx = aes_make_context();
|
|
aes128_key(ctx, keybuf);
|
|
aes_iv(ctx, (unsigned char *)key->iv);
|
|
aes_ssh2_decrypt_blk(ctx, key->keyblob, key->keyblob_len);
|
|
aes_free_context(ctx);
|
|
}
|
|
|
|
smemclr(&md5c, sizeof(md5c));
|
|
smemclr(keybuf, sizeof(keybuf));
|
|
}
|
|
|
|
/*
|
|
* Now we have a decrypted key blob, which contains an ASN.1
|
|
* encoded private key. We must now untangle the ASN.1.
|
|
*
|
|
* We expect the whole key blob to be formatted as a SEQUENCE
|
|
* (0x30 followed by a length code indicating that the rest of
|
|
* the blob is part of the sequence). Within that SEQUENCE we
|
|
* expect to see a bunch of INTEGERs. What those integers mean
|
|
* depends on the key type:
|
|
*
|
|
* - For RSA, we expect the integers to be 0, n, e, d, p, q,
|
|
* dmp1, dmq1, iqmp in that order. (The last three are d mod
|
|
* (p-1), d mod (q-1), inverse of q mod p respectively.)
|
|
*
|
|
* - For DSA, we expect them to be 0, p, q, g, y, x in that
|
|
* order.
|
|
*
|
|
* - In ECDSA the format is totally different: we see the
|
|
* SEQUENCE, but beneath is an INTEGER 1, OCTET STRING priv
|
|
* EXPLICIT [0] OID curve, EXPLICIT [1] BIT STRING pubPoint
|
|
*/
|
|
|
|
p = key->keyblob;
|
|
|
|
/* Expect the SEQUENCE header. Take its absence as a failure to
|
|
* decrypt, if the key was encrypted. */
|
|
ret = ber_read_id_len(p, key->keyblob_len, &id, &len, &flags);
|
|
p += ret;
|
|
if (ret < 0 || id != 16 || len < 0 ||
|
|
key->keyblob+key->keyblob_len-p < len) {
|
|
errmsg = "ASN.1 decoding failure";
|
|
retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
|
|
goto error;
|
|
}
|
|
|
|
/* Expect a load of INTEGERs. */
|
|
if (key->keytype == OP_RSA)
|
|
num_integers = 9;
|
|
else if (key->keytype == OP_DSA)
|
|
num_integers = 6;
|
|
else
|
|
num_integers = 0; /* placate compiler warnings */
|
|
|
|
|
|
if (key->keytype == OP_ECDSA) {
|
|
/* And now for something completely different */
|
|
unsigned char *priv;
|
|
int privlen;
|
|
const struct ssh_signkey *alg;
|
|
const struct ec_curve *curve;
|
|
int algnamelen, curvenamelen;
|
|
/* Read INTEGER 1 */
|
|
ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
|
|
&id, &len, &flags);
|
|
p += ret;
|
|
if (ret < 0 || id != 2 || len != 1 ||
|
|
key->keyblob+key->keyblob_len-p < len || p[0] != 1) {
|
|
errmsg = "ASN.1 decoding failure";
|
|
retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
|
|
goto error;
|
|
}
|
|
p += 1;
|
|
/* Read private key OCTET STRING */
|
|
ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
|
|
&id, &len, &flags);
|
|
p += ret;
|
|
if (ret < 0 || id != 4 || len < 0 ||
|
|
key->keyblob+key->keyblob_len-p < len) {
|
|
errmsg = "ASN.1 decoding failure";
|
|
retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
|
|
goto error;
|
|
}
|
|
priv = p;
|
|
privlen = len;
|
|
p += len;
|
|
/* Read curve OID */
|
|
ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
|
|
&id, &len, &flags);
|
|
p += ret;
|
|
if (ret < 0 || id != 0 || len < 0 ||
|
|
key->keyblob+key->keyblob_len-p < len) {
|
|
errmsg = "ASN.1 decoding failure";
|
|
retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
|
|
goto error;
|
|
}
|
|
ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
|
|
&id, &len, &flags);
|
|
p += ret;
|
|
if (ret < 0 || id != 6 || len < 0 ||
|
|
key->keyblob+key->keyblob_len-p < len) {
|
|
errmsg = "ASN.1 decoding failure";
|
|
retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
|
|
goto error;
|
|
}
|
|
alg = ec_alg_by_oid(len, p, &curve);
|
|
if (!alg) {
|
|
errmsg = "Unsupported ECDSA curve.";
|
|
retval = NULL;
|
|
goto error;
|
|
}
|
|
p += len;
|
|
/* Read BIT STRING point */
|
|
ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
|
|
&id, &len, &flags);
|
|
p += ret;
|
|
if (ret < 0 || id != 1 || len < 0 ||
|
|
key->keyblob+key->keyblob_len-p < len) {
|
|
errmsg = "ASN.1 decoding failure";
|
|
retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
|
|
goto error;
|
|
}
|
|
ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
|
|
&id, &len, &flags);
|
|
p += ret;
|
|
if (ret < 0 || id != 3 || len < 0 ||
|
|
key->keyblob+key->keyblob_len-p < len ||
|
|
len != ((((curve->fieldBits + 7) / 8) * 2) + 2)) {
|
|
errmsg = "ASN.1 decoding failure";
|
|
retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
|
|
goto error;
|
|
}
|
|
p += 1; len -= 1; /* Skip 0x00 before point */
|
|
|
|
/* Construct the key */
|
|
retkey = snew(struct ssh2_userkey);
|
|
if (!retkey) {
|
|
errmsg = "out of memory";
|
|
goto error;
|
|
}
|
|
retkey->alg = alg;
|
|
blob = snewn((4+19 + 4+8 + 4+len) + (4+1+privlen), unsigned char);
|
|
if (!blob) {
|
|
sfree(retkey);
|
|
errmsg = "out of memory";
|
|
goto error;
|
|
}
|
|
|
|
q = blob;
|
|
|
|
algnamelen = strlen(alg->name);
|
|
PUT_32BIT(q, algnamelen); q += 4;
|
|
memcpy(q, alg->name, algnamelen); q += algnamelen;
|
|
|
|
curvenamelen = strlen(curve->name);
|
|
PUT_32BIT(q, curvenamelen); q += 4;
|
|
memcpy(q, curve->name, curvenamelen); q += curvenamelen;
|
|
|
|
PUT_32BIT(q, len); q += 4;
|
|
memcpy(q, p, len); q += len;
|
|
|
|
/*
|
|
* To be acceptable to our createkey(), the private blob must
|
|
* contain a valid mpint, i.e. without the top bit set. But
|
|
* the input private string may have the top bit set, so we
|
|
* prefix a zero byte to ensure createkey() doesn't fail for
|
|
* that reason.
|
|
*/
|
|
PUT_32BIT(q, privlen+1);
|
|
q[4] = 0;
|
|
memcpy(q+5, priv, privlen);
|
|
|
|
retkey->data = retkey->alg->createkey(retkey->alg,
|
|
blob, q-blob,
|
|
q, 5+privlen);
|
|
|
|
if (!retkey->data) {
|
|
sfree(retkey);
|
|
errmsg = "unable to create key data structure";
|
|
goto error;
|
|
}
|
|
|
|
} else if (key->keytype == OP_RSA || key->keytype == OP_DSA) {
|
|
|
|
/*
|
|
* Space to create key blob in.
|
|
*/
|
|
blobsize = 256+key->keyblob_len;
|
|
blob = snewn(blobsize, unsigned char);
|
|
PUT_32BIT(blob, 7);
|
|
if (key->keytype == OP_DSA)
|
|
memcpy(blob+4, "ssh-dss", 7);
|
|
else if (key->keytype == OP_RSA)
|
|
memcpy(blob+4, "ssh-rsa", 7);
|
|
blobptr = 4+7;
|
|
privptr = -1;
|
|
|
|
for (i = 0; i < num_integers; i++) {
|
|
ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
|
|
&id, &len, &flags);
|
|
p += ret;
|
|
if (ret < 0 || id != 2 || len < 0 ||
|
|
key->keyblob+key->keyblob_len-p < len) {
|
|
errmsg = "ASN.1 decoding failure";
|
|
retval = key->encrypted ? SSH2_WRONG_PASSPHRASE : NULL;
|
|
goto error;
|
|
}
|
|
|
|
if (i == 0) {
|
|
/*
|
|
* The first integer should be zero always (I think
|
|
* this is some sort of version indication).
|
|
*/
|
|
if (len != 1 || p[0] != 0) {
|
|
errmsg = "version number mismatch";
|
|
goto error;
|
|
}
|
|
} else if (key->keytype == OP_RSA) {
|
|
/*
|
|
* Integers 1 and 2 go into the public blob but in the
|
|
* opposite order; integers 3, 4, 5 and 8 go into the
|
|
* private blob. The other two (6 and 7) are ignored.
|
|
*/
|
|
if (i == 1) {
|
|
/* Save the details for after we deal with number 2. */
|
|
modptr = (char *)p;
|
|
modlen = len;
|
|
} else if (i != 6 && i != 7) {
|
|
PUT_32BIT(blob+blobptr, len);
|
|
memcpy(blob+blobptr+4, p, len);
|
|
blobptr += 4+len;
|
|
if (i == 2) {
|
|
PUT_32BIT(blob+blobptr, modlen);
|
|
memcpy(blob+blobptr+4, modptr, modlen);
|
|
blobptr += 4+modlen;
|
|
privptr = blobptr;
|
|
}
|
|
}
|
|
} else if (key->keytype == OP_DSA) {
|
|
/*
|
|
* Integers 1-4 go into the public blob; integer 5 goes
|
|
* into the private blob.
|
|
*/
|
|
PUT_32BIT(blob+blobptr, len);
|
|
memcpy(blob+blobptr+4, p, len);
|
|
blobptr += 4+len;
|
|
if (i == 4)
|
|
privptr = blobptr;
|
|
}
|
|
|
|
/* Skip past the number. */
|
|
p += len;
|
|
}
|
|
|
|
/*
|
|
* Now put together the actual key. Simplest way to do this is
|
|
* to assemble our own key blobs and feed them to the createkey
|
|
* functions; this is a bit faffy but it does mean we get all
|
|
* the sanity checks for free.
|
|
*/
|
|
assert(privptr > 0); /* should have bombed by now if not */
|
|
retkey = snew(struct ssh2_userkey);
|
|
retkey->alg = (key->keytype == OP_RSA ? &ssh_rsa : &ssh_dss);
|
|
retkey->data = retkey->alg->createkey(retkey->alg, blob, privptr,
|
|
blob+privptr,
|
|
blobptr-privptr);
|
|
if (!retkey->data) {
|
|
sfree(retkey);
|
|
errmsg = "unable to create key data structure";
|
|
goto error;
|
|
}
|
|
|
|
} else {
|
|
assert(0 && "Bad key type from load_openssh_pem_key");
|
|
errmsg = "Bad key type from load_openssh_pem_key";
|
|
goto error;
|
|
}
|
|
|
|
/*
|
|
* The old key format doesn't include a comment in the private
|
|
* key file.
|
|
*/
|
|
retkey->comment = dupstr("imported-openssh-key");
|
|
|
|
errmsg = NULL; /* no error */
|
|
retval = retkey;
|
|
|
|
error:
|
|
if (blob) {
|
|
smemclr(blob, blobsize);
|
|
sfree(blob);
|
|
}
|
|
smemclr(key->keyblob, key->keyblob_size);
|
|
sfree(key->keyblob);
|
|
smemclr(key, sizeof(*key));
|
|
sfree(key);
|
|
if (errmsg_p) *errmsg_p = errmsg;
|
|
return retval;
|
|
}
|
|
|
|
int openssh_pem_write(const Filename *filename, struct ssh2_userkey *key,
|
|
char *passphrase)
|
|
{
|
|
unsigned char *pubblob, *privblob, *spareblob;
|
|
int publen, privlen, sparelen = 0;
|
|
unsigned char *outblob;
|
|
int outlen;
|
|
struct mpint_pos numbers[9];
|
|
int nnumbers, pos, len, seqlen, i;
|
|
const char *header, *footer;
|
|
char zero[1];
|
|
unsigned char iv[8];
|
|
int ret = 0;
|
|
FILE *fp;
|
|
|
|
/*
|
|
* Fetch the key blobs.
|
|
*/
|
|
pubblob = key->alg->public_blob(key->data, &publen);
|
|
privblob = key->alg->private_blob(key->data, &privlen);
|
|
spareblob = outblob = NULL;
|
|
|
|
outblob = NULL;
|
|
len = 0;
|
|
|
|
/*
|
|
* Encode the OpenSSH key blob, and also decide on the header
|
|
* line.
|
|
*/
|
|
if (key->alg == &ssh_rsa || key->alg == &ssh_dss) {
|
|
/*
|
|
* The RSA and DSS handlers share some code because the two
|
|
* key types have very similar ASN.1 representations, as a
|
|
* plain SEQUENCE of big integers. So we set up a list of
|
|
* bignums per key type and then construct the actual blob in
|
|
* common code after that.
|
|
*/
|
|
if (key->alg == &ssh_rsa) {
|
|
int pos;
|
|
struct mpint_pos n, e, d, p, q, iqmp, dmp1, dmq1;
|
|
Bignum bd, bp, bq, bdmp1, bdmq1;
|
|
|
|
/*
|
|
* These blobs were generated from inside PuTTY, so we needn't
|
|
* treat them as untrusted.
|
|
*/
|
|
pos = 4 + GET_32BIT(pubblob);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &e);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &n);
|
|
pos = 0;
|
|
pos += ssh2_read_mpint(privblob+pos, privlen-pos, &d);
|
|
pos += ssh2_read_mpint(privblob+pos, privlen-pos, &p);
|
|
pos += ssh2_read_mpint(privblob+pos, privlen-pos, &q);
|
|
pos += ssh2_read_mpint(privblob+pos, privlen-pos, &iqmp);
|
|
|
|
assert(e.start && iqmp.start); /* can't go wrong */
|
|
|
|
/* We also need d mod (p-1) and d mod (q-1). */
|
|
bd = bignum_from_bytes(d.start, d.bytes);
|
|
bp = bignum_from_bytes(p.start, p.bytes);
|
|
bq = bignum_from_bytes(q.start, q.bytes);
|
|
decbn(bp);
|
|
decbn(bq);
|
|
bdmp1 = bigmod(bd, bp);
|
|
bdmq1 = bigmod(bd, bq);
|
|
freebn(bd);
|
|
freebn(bp);
|
|
freebn(bq);
|
|
|
|
dmp1.bytes = (bignum_bitcount(bdmp1)+8)/8;
|
|
dmq1.bytes = (bignum_bitcount(bdmq1)+8)/8;
|
|
sparelen = dmp1.bytes + dmq1.bytes;
|
|
spareblob = snewn(sparelen, unsigned char);
|
|
dmp1.start = spareblob;
|
|
dmq1.start = spareblob + dmp1.bytes;
|
|
for (i = 0; i < dmp1.bytes; i++)
|
|
spareblob[i] = bignum_byte(bdmp1, dmp1.bytes-1 - i);
|
|
for (i = 0; i < dmq1.bytes; i++)
|
|
spareblob[i+dmp1.bytes] = bignum_byte(bdmq1, dmq1.bytes-1 - i);
|
|
freebn(bdmp1);
|
|
freebn(bdmq1);
|
|
|
|
numbers[0].start = zero; numbers[0].bytes = 1; zero[0] = '\0';
|
|
numbers[1] = n;
|
|
numbers[2] = e;
|
|
numbers[3] = d;
|
|
numbers[4] = p;
|
|
numbers[5] = q;
|
|
numbers[6] = dmp1;
|
|
numbers[7] = dmq1;
|
|
numbers[8] = iqmp;
|
|
|
|
nnumbers = 9;
|
|
header = "-----BEGIN RSA PRIVATE KEY-----\n";
|
|
footer = "-----END RSA PRIVATE KEY-----\n";
|
|
} else { /* ssh-dss */
|
|
int pos;
|
|
struct mpint_pos p, q, g, y, x;
|
|
|
|
/*
|
|
* These blobs were generated from inside PuTTY, so we needn't
|
|
* treat them as untrusted.
|
|
*/
|
|
pos = 4 + GET_32BIT(pubblob);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &p);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &q);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &g);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &y);
|
|
pos = 0;
|
|
pos += ssh2_read_mpint(privblob+pos, privlen-pos, &x);
|
|
|
|
assert(y.start && x.start); /* can't go wrong */
|
|
|
|
numbers[0].start = zero; numbers[0].bytes = 1; zero[0] = '\0';
|
|
numbers[1] = p;
|
|
numbers[2] = q;
|
|
numbers[3] = g;
|
|
numbers[4] = y;
|
|
numbers[5] = x;
|
|
|
|
nnumbers = 6;
|
|
header = "-----BEGIN DSA PRIVATE KEY-----\n";
|
|
footer = "-----END DSA PRIVATE KEY-----\n";
|
|
}
|
|
|
|
/*
|
|
* Now count up the total size of the ASN.1 encoded integers,
|
|
* so as to determine the length of the containing SEQUENCE.
|
|
*/
|
|
len = 0;
|
|
for (i = 0; i < nnumbers; i++) {
|
|
len += ber_write_id_len(NULL, 2, numbers[i].bytes, 0);
|
|
len += numbers[i].bytes;
|
|
}
|
|
seqlen = len;
|
|
/* Now add on the SEQUENCE header. */
|
|
len += ber_write_id_len(NULL, 16, seqlen, ASN1_CONSTRUCTED);
|
|
|
|
/*
|
|
* Now we know how big outblob needs to be. Allocate it.
|
|
*/
|
|
outblob = snewn(len, unsigned char);
|
|
|
|
/*
|
|
* And write the data into it.
|
|
*/
|
|
pos = 0;
|
|
pos += ber_write_id_len(outblob+pos, 16, seqlen, ASN1_CONSTRUCTED);
|
|
for (i = 0; i < nnumbers; i++) {
|
|
pos += ber_write_id_len(outblob+pos, 2, numbers[i].bytes, 0);
|
|
memcpy(outblob+pos, numbers[i].start, numbers[i].bytes);
|
|
pos += numbers[i].bytes;
|
|
}
|
|
} else if (key->alg == &ssh_ecdsa_nistp256 ||
|
|
key->alg == &ssh_ecdsa_nistp384 ||
|
|
key->alg == &ssh_ecdsa_nistp521) {
|
|
const unsigned char *oid;
|
|
int oidlen;
|
|
int pointlen;
|
|
|
|
/*
|
|
* Structure of asn1:
|
|
* SEQUENCE
|
|
* INTEGER 1
|
|
* OCTET STRING (private key)
|
|
* [0]
|
|
* OID (curve)
|
|
* [1]
|
|
* BIT STRING (0x00 public key point)
|
|
*/
|
|
oid = ec_alg_oid(key->alg, &oidlen);
|
|
pointlen = (((struct ec_key *)key->data)->publicKey.curve->fieldBits
|
|
+ 7) / 8 * 2;
|
|
|
|
len = ber_write_id_len(NULL, 2, 1, 0);
|
|
len += 1;
|
|
len += ber_write_id_len(NULL, 4, privlen - 4, 0);
|
|
len+= privlen - 4;
|
|
len += ber_write_id_len(NULL, 0, oidlen +
|
|
ber_write_id_len(NULL, 6, oidlen, 0),
|
|
ASN1_CLASS_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED);
|
|
len += ber_write_id_len(NULL, 6, oidlen, 0);
|
|
len += oidlen;
|
|
len += ber_write_id_len(NULL, 1, 2 + pointlen +
|
|
ber_write_id_len(NULL, 3, 2 + pointlen, 0),
|
|
ASN1_CLASS_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED);
|
|
len += ber_write_id_len(NULL, 3, 2 + pointlen, 0);
|
|
len += 2 + pointlen;
|
|
|
|
seqlen = len;
|
|
len += ber_write_id_len(NULL, 16, seqlen, ASN1_CONSTRUCTED);
|
|
|
|
outblob = snewn(len, unsigned char);
|
|
assert(outblob);
|
|
|
|
pos = 0;
|
|
pos += ber_write_id_len(outblob+pos, 16, seqlen, ASN1_CONSTRUCTED);
|
|
pos += ber_write_id_len(outblob+pos, 2, 1, 0);
|
|
outblob[pos++] = 1;
|
|
pos += ber_write_id_len(outblob+pos, 4, privlen - 4, 0);
|
|
memcpy(outblob+pos, privblob + 4, privlen - 4);
|
|
pos += privlen - 4;
|
|
pos += ber_write_id_len(outblob+pos, 0, oidlen +
|
|
ber_write_id_len(NULL, 6, oidlen, 0),
|
|
ASN1_CLASS_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED);
|
|
pos += ber_write_id_len(outblob+pos, 6, oidlen, 0);
|
|
memcpy(outblob+pos, oid, oidlen);
|
|
pos += oidlen;
|
|
pos += ber_write_id_len(outblob+pos, 1, 2 + pointlen +
|
|
ber_write_id_len(NULL, 3, 2 + pointlen, 0),
|
|
ASN1_CLASS_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED);
|
|
pos += ber_write_id_len(outblob+pos, 3, 2 + pointlen, 0);
|
|
outblob[pos++] = 0;
|
|
memcpy(outblob+pos, pubblob+39, 1 + pointlen);
|
|
pos += 1 + pointlen;
|
|
|
|
header = "-----BEGIN EC PRIVATE KEY-----\n";
|
|
footer = "-----END EC PRIVATE KEY-----\n";
|
|
} else {
|
|
assert(0); /* zoinks! */
|
|
exit(1); /* XXX: GCC doesn't understand assert() on some systems. */
|
|
}
|
|
|
|
/*
|
|
* Encrypt the key.
|
|
*
|
|
* For the moment, we still encrypt our OpenSSH keys using
|
|
* old-style 3DES.
|
|
*/
|
|
if (passphrase) {
|
|
struct MD5Context md5c;
|
|
unsigned char keybuf[32];
|
|
|
|
/*
|
|
* Round up to the cipher block size, ensuring we have at
|
|
* least one byte of padding (see below).
|
|
*/
|
|
outlen = (len+8) &~ 7;
|
|
{
|
|
unsigned char *tmp = snewn(outlen, unsigned char);
|
|
memcpy(tmp, outblob, len);
|
|
smemclr(outblob, len);
|
|
sfree(outblob);
|
|
outblob = tmp;
|
|
}
|
|
|
|
/*
|
|
* Padding on OpenSSH keys is deterministic. The number of
|
|
* padding bytes is always more than zero, and always at most
|
|
* the cipher block length. The value of each padding byte is
|
|
* equal to the number of padding bytes. So a plaintext that's
|
|
* an exact multiple of the block size will be padded with 08
|
|
* 08 08 08 08 08 08 08 (assuming a 64-bit block cipher); a
|
|
* plaintext one byte less than a multiple of the block size
|
|
* will be padded with just 01.
|
|
*
|
|
* This enables the OpenSSL key decryption function to strip
|
|
* off the padding algorithmically and return the unpadded
|
|
* plaintext to the next layer: it looks at the final byte, and
|
|
* then expects to find that many bytes at the end of the data
|
|
* with the same value. Those are all removed and the rest is
|
|
* returned.
|
|
*/
|
|
assert(pos == len);
|
|
while (pos < outlen) {
|
|
outblob[pos++] = outlen - len;
|
|
}
|
|
|
|
/*
|
|
* Invent an iv. Then derive encryption key from passphrase
|
|
* and iv/salt:
|
|
*
|
|
* - let block A equal MD5(passphrase || iv)
|
|
* - let block B equal MD5(A || passphrase || iv)
|
|
* - block C would be MD5(B || passphrase || iv) and so on
|
|
* - encryption key is the first N bytes of A || B
|
|
*/
|
|
for (i = 0; i < 8; i++) iv[i] = random_byte();
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
|
|
MD5Update(&md5c, iv, 8);
|
|
MD5Final(keybuf, &md5c);
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, keybuf, 16);
|
|
MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
|
|
MD5Update(&md5c, iv, 8);
|
|
MD5Final(keybuf+16, &md5c);
|
|
|
|
/*
|
|
* Now encrypt the key blob.
|
|
*/
|
|
des3_encrypt_pubkey_ossh(keybuf, iv, outblob, outlen);
|
|
|
|
smemclr(&md5c, sizeof(md5c));
|
|
smemclr(keybuf, sizeof(keybuf));
|
|
} else {
|
|
/*
|
|
* If no encryption, the blob has exactly its original
|
|
* cleartext size.
|
|
*/
|
|
outlen = len;
|
|
}
|
|
|
|
/*
|
|
* And save it. We'll use Unix line endings just in case it's
|
|
* subsequently transferred in binary mode.
|
|
*/
|
|
fp = f_open(filename, "wb", TRUE); /* ensure Unix line endings */
|
|
if (!fp)
|
|
goto error;
|
|
fputs(header, fp);
|
|
if (passphrase) {
|
|
fprintf(fp, "Proc-Type: 4,ENCRYPTED\nDEK-Info: DES-EDE3-CBC,");
|
|
for (i = 0; i < 8; i++)
|
|
fprintf(fp, "%02X", iv[i]);
|
|
fprintf(fp, "\n\n");
|
|
}
|
|
base64_encode(fp, outblob, outlen, 64);
|
|
fputs(footer, fp);
|
|
fclose(fp);
|
|
ret = 1;
|
|
|
|
error:
|
|
if (outblob) {
|
|
smemclr(outblob, outlen);
|
|
sfree(outblob);
|
|
}
|
|
if (spareblob) {
|
|
smemclr(spareblob, sparelen);
|
|
sfree(spareblob);
|
|
}
|
|
if (privblob) {
|
|
smemclr(privblob, privlen);
|
|
sfree(privblob);
|
|
}
|
|
if (pubblob) {
|
|
smemclr(pubblob, publen);
|
|
sfree(pubblob);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
* Code to read and write OpenSSH private keys in the new-style format.
|
|
*/
|
|
|
|
typedef enum {
|
|
ON_E_NONE, ON_E_AES256CBC, ON_E_AES256CTR
|
|
} openssh_new_cipher;
|
|
typedef enum {
|
|
ON_K_NONE, ON_K_BCRYPT
|
|
} openssh_new_kdf;
|
|
|
|
struct openssh_new_key {
|
|
openssh_new_cipher cipher;
|
|
openssh_new_kdf kdf;
|
|
union {
|
|
struct {
|
|
int rounds;
|
|
/* This points to a position within keyblob, not a
|
|
* separately allocated thing */
|
|
const unsigned char *salt;
|
|
int saltlen;
|
|
} bcrypt;
|
|
} kdfopts;
|
|
int nkeys, key_wanted;
|
|
/* This too points to a position within keyblob */
|
|
unsigned char *privatestr;
|
|
int privatelen;
|
|
|
|
unsigned char *keyblob;
|
|
int keyblob_len, keyblob_size;
|
|
};
|
|
|
|
static struct openssh_new_key *load_openssh_new_key(const Filename *filename,
|
|
const char **errmsg_p)
|
|
{
|
|
struct openssh_new_key *ret;
|
|
FILE *fp = NULL;
|
|
char *line = NULL;
|
|
const char *errmsg;
|
|
char *p;
|
|
char base64_bit[4];
|
|
int base64_chars = 0;
|
|
const void *filedata;
|
|
int filelen;
|
|
const void *string, *kdfopts, *bcryptsalt, *pubkey;
|
|
int stringlen, kdfoptlen, bcryptsaltlen, pubkeylen;
|
|
unsigned bcryptrounds, nkeys, key_index;
|
|
|
|
ret = snew(struct openssh_new_key);
|
|
ret->keyblob = NULL;
|
|
ret->keyblob_len = ret->keyblob_size = 0;
|
|
|
|
fp = f_open(filename, "r", FALSE);
|
|
if (!fp) {
|
|
errmsg = "unable to open key file";
|
|
goto error;
|
|
}
|
|
|
|
if (!(line = fgetline(fp))) {
|
|
errmsg = "unexpected end of file";
|
|
goto error;
|
|
}
|
|
strip_crlf(line);
|
|
if (0 != strcmp(line, "-----BEGIN OPENSSH PRIVATE KEY-----")) {
|
|
errmsg = "file does not begin with OpenSSH new-style key header";
|
|
goto error;
|
|
}
|
|
smemclr(line, strlen(line));
|
|
sfree(line);
|
|
line = NULL;
|
|
|
|
while (1) {
|
|
if (!(line = fgetline(fp))) {
|
|
errmsg = "unexpected end of file";
|
|
goto error;
|
|
}
|
|
strip_crlf(line);
|
|
if (0 == strcmp(line, "-----END OPENSSH PRIVATE KEY-----")) {
|
|
sfree(line);
|
|
line = NULL;
|
|
break; /* done */
|
|
}
|
|
|
|
p = line;
|
|
while (isbase64(*p)) {
|
|
base64_bit[base64_chars++] = *p;
|
|
if (base64_chars == 4) {
|
|
unsigned char out[3];
|
|
int len;
|
|
|
|
base64_chars = 0;
|
|
|
|
len = base64_decode_atom(base64_bit, out);
|
|
|
|
if (len <= 0) {
|
|
errmsg = "invalid base64 encoding";
|
|
goto error;
|
|
}
|
|
|
|
if (ret->keyblob_len + len > ret->keyblob_size) {
|
|
ret->keyblob_size = ret->keyblob_len + len + 256;
|
|
ret->keyblob = sresize(ret->keyblob, ret->keyblob_size,
|
|
unsigned char);
|
|
}
|
|
|
|
memcpy(ret->keyblob + ret->keyblob_len, out, len);
|
|
ret->keyblob_len += len;
|
|
|
|
smemclr(out, sizeof(out));
|
|
}
|
|
|
|
p++;
|
|
}
|
|
smemclr(line, strlen(line));
|
|
sfree(line);
|
|
line = NULL;
|
|
}
|
|
|
|
fclose(fp);
|
|
fp = NULL;
|
|
|
|
if (ret->keyblob_len == 0 || !ret->keyblob) {
|
|
errmsg = "key body not present";
|
|
goto error;
|
|
}
|
|
|
|
filedata = ret->keyblob;
|
|
filelen = ret->keyblob_len;
|
|
|
|
if (filelen < 15 || 0 != memcmp(filedata, "openssh-key-v1\0", 15)) {
|
|
errmsg = "new-style OpenSSH magic number missing\n";
|
|
goto error;
|
|
}
|
|
filedata = (const char *)filedata + 15;
|
|
filelen -= 15;
|
|
|
|
if (!(string = get_ssh_string(&filelen, &filedata, &stringlen))) {
|
|
errmsg = "encountered EOF before cipher name\n";
|
|
goto error;
|
|
}
|
|
if (match_ssh_id(stringlen, string, "none")) {
|
|
ret->cipher = ON_E_NONE;
|
|
} else if (match_ssh_id(stringlen, string, "aes256-cbc")) {
|
|
ret->cipher = ON_E_AES256CBC;
|
|
} else if (match_ssh_id(stringlen, string, "aes256-ctr")) {
|
|
ret->cipher = ON_E_AES256CTR;
|
|
} else {
|
|
errmsg = "unrecognised cipher name\n";
|
|
goto error;
|
|
}
|
|
|
|
if (!(string = get_ssh_string(&filelen, &filedata, &stringlen))) {
|
|
errmsg = "encountered EOF before kdf name\n";
|
|
goto error;
|
|
}
|
|
if (match_ssh_id(stringlen, string, "none")) {
|
|
ret->kdf = ON_K_NONE;
|
|
} else if (match_ssh_id(stringlen, string, "bcrypt")) {
|
|
ret->kdf = ON_K_BCRYPT;
|
|
} else {
|
|
errmsg = "unrecognised kdf name\n";
|
|
goto error;
|
|
}
|
|
|
|
if (!(kdfopts = get_ssh_string(&filelen, &filedata, &kdfoptlen))) {
|
|
errmsg = "encountered EOF before kdf options\n";
|
|
goto error;
|
|
}
|
|
switch (ret->kdf) {
|
|
case ON_K_NONE:
|
|
if (kdfoptlen != 0) {
|
|
errmsg = "expected empty options string for 'none' kdf";
|
|
goto error;
|
|
}
|
|
break;
|
|
case ON_K_BCRYPT:
|
|
if (!(bcryptsalt = get_ssh_string(&kdfoptlen, &kdfopts,
|
|
&bcryptsaltlen))) {
|
|
errmsg = "bcrypt options string did not contain salt\n";
|
|
goto error;
|
|
}
|
|
if (!get_ssh_uint32(&kdfoptlen, &kdfopts, &bcryptrounds)) {
|
|
errmsg = "bcrypt options string did not contain round count\n";
|
|
goto error;
|
|
}
|
|
ret->kdfopts.bcrypt.salt = bcryptsalt;
|
|
ret->kdfopts.bcrypt.saltlen = bcryptsaltlen;
|
|
ret->kdfopts.bcrypt.rounds = bcryptrounds;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* At this point we expect a uint32 saying how many keys are
|
|
* stored in this file. OpenSSH new-style key files can
|
|
* contain more than one. Currently we don't have any user
|
|
* interface to specify which one we're trying to extract, so
|
|
* we just bomb out with an error if more than one is found in
|
|
* the file. However, I've put in all the mechanism here to
|
|
* extract the nth one for a given n, in case we later connect
|
|
* up some UI to that mechanism. Just arrange that the
|
|
* 'key_wanted' field is set to a value in the range [0,
|
|
* nkeys) by some mechanism.
|
|
*/
|
|
if (!get_ssh_uint32(&filelen, &filedata, &nkeys)) {
|
|
errmsg = "encountered EOF before key count\n";
|
|
goto error;
|
|
}
|
|
if (nkeys != 1) {
|
|
errmsg = "multiple keys in new-style OpenSSH key file "
|
|
"not supported\n";
|
|
goto error;
|
|
}
|
|
ret->nkeys = nkeys;
|
|
ret->key_wanted = 0;
|
|
|
|
for (key_index = 0; key_index < nkeys; key_index++) {
|
|
if (!(pubkey = get_ssh_string(&filelen, &filedata, &pubkeylen))) {
|
|
errmsg = "encountered EOF before kdf options\n";
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now we expect a string containing the encrypted part of the
|
|
* key file.
|
|
*/
|
|
if (!(string = get_ssh_string(&filelen, &filedata, &stringlen))) {
|
|
errmsg = "encountered EOF before private key container\n";
|
|
goto error;
|
|
}
|
|
ret->privatestr = (unsigned char *)string;
|
|
ret->privatelen = stringlen;
|
|
|
|
/*
|
|
* And now we're done, until asked to actually decrypt.
|
|
*/
|
|
|
|
smemclr(base64_bit, sizeof(base64_bit));
|
|
if (errmsg_p) *errmsg_p = NULL;
|
|
return ret;
|
|
|
|
error:
|
|
if (line) {
|
|
smemclr(line, strlen(line));
|
|
sfree(line);
|
|
line = NULL;
|
|
}
|
|
smemclr(base64_bit, sizeof(base64_bit));
|
|
if (ret) {
|
|
if (ret->keyblob) {
|
|
smemclr(ret->keyblob, ret->keyblob_size);
|
|
sfree(ret->keyblob);
|
|
}
|
|
smemclr(ret, sizeof(*ret));
|
|
sfree(ret);
|
|
}
|
|
if (errmsg_p) *errmsg_p = errmsg;
|
|
if (fp) fclose(fp);
|
|
return NULL;
|
|
}
|
|
|
|
int openssh_new_encrypted(const Filename *filename)
|
|
{
|
|
struct openssh_new_key *key = load_openssh_new_key(filename, NULL);
|
|
int ret;
|
|
|
|
if (!key)
|
|
return 0;
|
|
ret = (key->cipher != ON_E_NONE);
|
|
smemclr(key->keyblob, key->keyblob_size);
|
|
sfree(key->keyblob);
|
|
smemclr(key, sizeof(*key));
|
|
sfree(key);
|
|
return ret;
|
|
}
|
|
|
|
struct ssh2_userkey *openssh_new_read(const Filename *filename,
|
|
char *passphrase,
|
|
const char **errmsg_p)
|
|
{
|
|
struct openssh_new_key *key = load_openssh_new_key(filename, errmsg_p);
|
|
struct ssh2_userkey *retkey = NULL;
|
|
int i;
|
|
struct ssh2_userkey *retval = NULL;
|
|
const char *errmsg;
|
|
unsigned checkint0, checkint1;
|
|
const void *priv, *string;
|
|
int privlen, stringlen, key_index;
|
|
const struct ssh_signkey *alg = NULL;
|
|
|
|
if (!key)
|
|
return NULL;
|
|
|
|
if (key->cipher != ON_E_NONE) {
|
|
unsigned char keybuf[48];
|
|
int keysize;
|
|
|
|
/*
|
|
* Construct the decryption key, and decrypt the string.
|
|
*/
|
|
switch (key->cipher) {
|
|
case ON_E_NONE:
|
|
keysize = 0;
|
|
break;
|
|
case ON_E_AES256CBC:
|
|
case ON_E_AES256CTR:
|
|
keysize = 48; /* 32 byte key + 16 byte IV */
|
|
break;
|
|
default:
|
|
assert(0 && "Bad cipher enumeration value");
|
|
}
|
|
assert(keysize <= sizeof(keybuf));
|
|
switch (key->kdf) {
|
|
case ON_K_NONE:
|
|
memset(keybuf, 0, keysize);
|
|
break;
|
|
case ON_K_BCRYPT:
|
|
openssh_bcrypt(passphrase,
|
|
key->kdfopts.bcrypt.salt,
|
|
key->kdfopts.bcrypt.saltlen,
|
|
key->kdfopts.bcrypt.rounds,
|
|
keybuf, keysize);
|
|
break;
|
|
default:
|
|
assert(0 && "Bad kdf enumeration value");
|
|
}
|
|
switch (key->cipher) {
|
|
case ON_E_NONE:
|
|
break;
|
|
case ON_E_AES256CBC:
|
|
case ON_E_AES256CTR:
|
|
if (key->privatelen % 16 != 0) {
|
|
errmsg = "private key container length is not a"
|
|
" multiple of AES block size\n";
|
|
goto error;
|
|
}
|
|
{
|
|
void *ctx = aes_make_context();
|
|
aes256_key(ctx, keybuf);
|
|
aes_iv(ctx, keybuf + 32);
|
|
if (key->cipher == ON_E_AES256CBC) {
|
|
aes_ssh2_decrypt_blk(ctx, key->privatestr,
|
|
key->privatelen);
|
|
}
|
|
else {
|
|
aes_ssh2_sdctr(ctx, key->privatestr,
|
|
key->privatelen);
|
|
}
|
|
aes_free_context(ctx);
|
|
}
|
|
break;
|
|
default:
|
|
assert(0 && "Bad cipher enumeration value");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now parse the entire encrypted section, and extract the key
|
|
* identified by key_wanted.
|
|
*/
|
|
priv = key->privatestr;
|
|
privlen = key->privatelen;
|
|
|
|
if (!get_ssh_uint32(&privlen, &priv, &checkint0) ||
|
|
!get_ssh_uint32(&privlen, &priv, &checkint1) ||
|
|
checkint0 != checkint1) {
|
|
errmsg = "decryption check failed";
|
|
goto error;
|
|
}
|
|
|
|
retkey = NULL;
|
|
for (key_index = 0; key_index < key->nkeys; key_index++) {
|
|
const unsigned char *thiskey;
|
|
int thiskeylen;
|
|
|
|
/*
|
|
* Read the key type, which will tell us how to scan over
|
|
* the key to get to the next one.
|
|
*/
|
|
if (!(string = get_ssh_string(&privlen, &priv, &stringlen))) {
|
|
errmsg = "expected key type in private string";
|
|
goto error;
|
|
}
|
|
|
|
/*
|
|
* Preliminary key type identification, and decide how
|
|
* many pieces of key we expect to see. Currently
|
|
* (conveniently) all key types can be seen as some number
|
|
* of strings, so we just need to know how many of them to
|
|
* skip over. (The numbers below exclude the key comment.)
|
|
*/
|
|
{
|
|
/* find_pubkey_alg needs a zero-terminated copy of the
|
|
* algorithm name */
|
|
char *name_zt = dupprintf("%.*s", stringlen, (char *)string);
|
|
alg = find_pubkey_alg(name_zt);
|
|
sfree(name_zt);
|
|
}
|
|
|
|
if (!alg) {
|
|
errmsg = "private key type not recognised\n";
|
|
goto error;
|
|
}
|
|
|
|
thiskey = priv;
|
|
|
|
/*
|
|
* Skip over the pieces of key.
|
|
*/
|
|
for (i = 0; i < alg->openssh_private_npieces; i++) {
|
|
if (!(string = get_ssh_string(&privlen, &priv, &stringlen))) {
|
|
errmsg = "ran out of data in mid-private-key";
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
thiskeylen = (int)((const unsigned char *)priv -
|
|
(const unsigned char *)thiskey);
|
|
if (key_index == key->key_wanted) {
|
|
retkey = snew(struct ssh2_userkey);
|
|
retkey->comment = NULL;
|
|
retkey->alg = alg;
|
|
retkey->data = alg->openssh_createkey(alg, &thiskey, &thiskeylen);
|
|
if (!retkey->data) {
|
|
errmsg = "unable to create key data structure";
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Read the key comment.
|
|
*/
|
|
if (!(string = get_ssh_string(&privlen, &priv, &stringlen))) {
|
|
errmsg = "ran out of data at key comment";
|
|
goto error;
|
|
}
|
|
if (key_index == key->key_wanted) {
|
|
assert(retkey);
|
|
retkey->comment = dupprintf("%.*s", stringlen,
|
|
(const char *)string);
|
|
}
|
|
}
|
|
|
|
if (!retkey) {
|
|
errmsg = "key index out of range";
|
|
goto error;
|
|
}
|
|
|
|
/*
|
|
* Now we expect nothing left but padding.
|
|
*/
|
|
for (i = 0; i < privlen; i++) {
|
|
if (((const unsigned char *)priv)[i] != (unsigned char)(i+1)) {
|
|
errmsg = "padding at end of private string did not match";
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
errmsg = NULL; /* no error */
|
|
retval = retkey;
|
|
retkey = NULL; /* prevent the free */
|
|
|
|
error:
|
|
if (retkey) {
|
|
sfree(retkey->comment);
|
|
if (retkey->data) {
|
|
assert(alg);
|
|
alg->freekey(retkey->data);
|
|
}
|
|
sfree(retkey);
|
|
}
|
|
smemclr(key->keyblob, key->keyblob_size);
|
|
sfree(key->keyblob);
|
|
smemclr(key, sizeof(*key));
|
|
sfree(key);
|
|
if (errmsg_p) *errmsg_p = errmsg;
|
|
return retval;
|
|
}
|
|
|
|
int openssh_new_write(const Filename *filename, struct ssh2_userkey *key,
|
|
char *passphrase)
|
|
{
|
|
unsigned char *pubblob, *privblob, *outblob, *p;
|
|
unsigned char *private_section_start, *private_section_length_field;
|
|
int publen, privlen, commentlen, maxsize, padvalue, i;
|
|
unsigned checkint;
|
|
int ret = 0;
|
|
unsigned char bcrypt_salt[16];
|
|
const int bcrypt_rounds = 16;
|
|
FILE *fp;
|
|
|
|
/*
|
|
* Fetch the key blobs and find out the lengths of things.
|
|
*/
|
|
pubblob = key->alg->public_blob(key->data, &publen);
|
|
i = key->alg->openssh_fmtkey(key->data, NULL, 0);
|
|
privblob = snewn(i, unsigned char);
|
|
privlen = key->alg->openssh_fmtkey(key->data, privblob, i);
|
|
assert(privlen == i);
|
|
commentlen = strlen(key->comment);
|
|
|
|
/*
|
|
* Allocate enough space for the full binary key format. No need
|
|
* to be absolutely precise here.
|
|
*/
|
|
maxsize = (16 + /* magic number */
|
|
32 + /* cipher name string */
|
|
32 + /* kdf name string */
|
|
64 + /* kdf options string */
|
|
4 + /* key count */
|
|
4+publen + /* public key string */
|
|
4 + /* string header for private section */
|
|
8 + /* checkint x 2 */
|
|
4+strlen(key->alg->name) + /* key type string */
|
|
privlen + /* private blob */
|
|
4+commentlen + /* comment string */
|
|
16); /* padding at end of private section */
|
|
outblob = snewn(maxsize, unsigned char);
|
|
|
|
/*
|
|
* Construct the cleartext version of the blob.
|
|
*/
|
|
p = outblob;
|
|
|
|
/* Magic number. */
|
|
memcpy(p, "openssh-key-v1\0", 15);
|
|
p += 15;
|
|
|
|
/* Cipher and kdf names, and kdf options. */
|
|
if (!passphrase) {
|
|
memset(bcrypt_salt, 0, sizeof(bcrypt_salt)); /* prevent warnings */
|
|
p += put_string_z(p, "none");
|
|
p += put_string_z(p, "none");
|
|
p += put_string_z(p, "");
|
|
} else {
|
|
unsigned char *q;
|
|
for (i = 0; i < (int)sizeof(bcrypt_salt); i++)
|
|
bcrypt_salt[i] = random_byte();
|
|
p += put_string_z(p, "aes256-ctr");
|
|
p += put_string_z(p, "bcrypt");
|
|
q = p;
|
|
p += 4;
|
|
p += put_string(p, bcrypt_salt, sizeof(bcrypt_salt));
|
|
p += put_uint32(p, bcrypt_rounds);
|
|
PUT_32BIT_MSB_FIRST(q, (unsigned)(p - (q+4)));
|
|
}
|
|
|
|
/* Number of keys. */
|
|
p += put_uint32(p, 1);
|
|
|
|
/* Public blob. */
|
|
p += put_string(p, pubblob, publen);
|
|
|
|
/* Begin private section. */
|
|
private_section_length_field = p;
|
|
p += 4;
|
|
private_section_start = p;
|
|
|
|
/* checkint. */
|
|
checkint = 0;
|
|
for (i = 0; i < 4; i++)
|
|
checkint = (checkint << 8) + random_byte();
|
|
p += put_uint32(p, checkint);
|
|
p += put_uint32(p, checkint);
|
|
|
|
/* Private key. The main private blob goes inline, with no string
|
|
* wrapper. */
|
|
p += put_string_z(p, key->alg->name);
|
|
memcpy(p, privblob, privlen);
|
|
p += privlen;
|
|
|
|
/* Comment. */
|
|
p += put_string_z(p, key->comment);
|
|
|
|
/* Pad out the encrypted section. */
|
|
padvalue = 1;
|
|
do {
|
|
*p++ = padvalue++;
|
|
} while ((p - private_section_start) & 15);
|
|
|
|
assert(p - outblob < maxsize);
|
|
|
|
/* Go back and fill in the length field for the private section. */
|
|
PUT_32BIT_MSB_FIRST(private_section_length_field,
|
|
p - private_section_start);
|
|
|
|
if (passphrase) {
|
|
/*
|
|
* Encrypt the private section. We need 48 bytes of key
|
|
* material: 32 bytes AES key + 16 bytes iv.
|
|
*/
|
|
unsigned char keybuf[48];
|
|
void *ctx;
|
|
|
|
openssh_bcrypt(passphrase,
|
|
bcrypt_salt, sizeof(bcrypt_salt), bcrypt_rounds,
|
|
keybuf, sizeof(keybuf));
|
|
|
|
ctx = aes_make_context();
|
|
aes256_key(ctx, keybuf);
|
|
aes_iv(ctx, keybuf + 32);
|
|
aes_ssh2_sdctr(ctx, private_section_start,
|
|
p - private_section_start);
|
|
aes_free_context(ctx);
|
|
|
|
smemclr(keybuf, sizeof(keybuf));
|
|
}
|
|
|
|
/*
|
|
* And save it. We'll use Unix line endings just in case it's
|
|
* subsequently transferred in binary mode.
|
|
*/
|
|
fp = f_open(filename, "wb", TRUE); /* ensure Unix line endings */
|
|
if (!fp)
|
|
goto error;
|
|
fputs("-----BEGIN OPENSSH PRIVATE KEY-----\n", fp);
|
|
base64_encode(fp, outblob, p - outblob, 64);
|
|
fputs("-----END OPENSSH PRIVATE KEY-----\n", fp);
|
|
fclose(fp);
|
|
ret = 1;
|
|
|
|
error:
|
|
if (outblob) {
|
|
smemclr(outblob, maxsize);
|
|
sfree(outblob);
|
|
}
|
|
if (privblob) {
|
|
smemclr(privblob, privlen);
|
|
sfree(privblob);
|
|
}
|
|
if (pubblob) {
|
|
smemclr(pubblob, publen);
|
|
sfree(pubblob);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
* The switch function openssh_auto_write(), which chooses one of the
|
|
* concrete OpenSSH output formats based on the key type.
|
|
*/
|
|
int openssh_auto_write(const Filename *filename, struct ssh2_userkey *key,
|
|
char *passphrase)
|
|
{
|
|
/*
|
|
* The old OpenSSH format supports a fixed list of key types. We
|
|
* assume that anything not in that fixed list is newer, and hence
|
|
* will use the new format.
|
|
*/
|
|
if (key->alg == &ssh_dss ||
|
|
key->alg == &ssh_rsa ||
|
|
key->alg == &ssh_ecdsa_nistp256 ||
|
|
key->alg == &ssh_ecdsa_nistp384 ||
|
|
key->alg == &ssh_ecdsa_nistp521)
|
|
return openssh_pem_write(filename, key, passphrase);
|
|
else
|
|
return openssh_new_write(filename, key, passphrase);
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
* Code to read ssh.com private keys.
|
|
*/
|
|
|
|
/*
|
|
* The format of the base64 blob is largely SSH-2-packet-formatted,
|
|
* except that mpints are a bit different: they're more like the
|
|
* old SSH-1 mpint. You have a 32-bit bit count N, followed by
|
|
* (N+7)/8 bytes of data.
|
|
*
|
|
* So. The blob contains:
|
|
*
|
|
* - uint32 0x3f6ff9eb (magic number)
|
|
* - uint32 size (total blob size)
|
|
* - string key-type (see below)
|
|
* - string cipher-type (tells you if key is encrypted)
|
|
* - string encrypted-blob
|
|
*
|
|
* (The first size field includes the size field itself and the
|
|
* magic number before it. All other size fields are ordinary SSH-2
|
|
* strings, so the size field indicates how much data is to
|
|
* _follow_.)
|
|
*
|
|
* The encrypted blob, once decrypted, contains a single string
|
|
* which in turn contains the payload. (This allows padding to be
|
|
* added after that string while still making it clear where the
|
|
* real payload ends. Also it probably makes for a reasonable
|
|
* decryption check.)
|
|
*
|
|
* The payload blob, for an RSA key, contains:
|
|
* - mpint e
|
|
* - mpint d
|
|
* - mpint n (yes, the public and private stuff is intermixed)
|
|
* - mpint u (presumably inverse of p mod q)
|
|
* - mpint p (p is the smaller prime)
|
|
* - mpint q (q is the larger)
|
|
*
|
|
* For a DSA key, the payload blob contains:
|
|
* - uint32 0
|
|
* - mpint p
|
|
* - mpint g
|
|
* - mpint q
|
|
* - mpint y
|
|
* - mpint x
|
|
*
|
|
* Alternatively, if the parameters are `predefined', that
|
|
* (0,p,g,q) sequence can be replaced by a uint32 1 and a string
|
|
* containing some predefined parameter specification. *shudder*,
|
|
* but I doubt we'll encounter this in real life.
|
|
*
|
|
* The key type strings are ghastly. The RSA key I looked at had a
|
|
* type string of
|
|
*
|
|
* `if-modn{sign{rsa-pkcs1-sha1},encrypt{rsa-pkcs1v2-oaep}}'
|
|
*
|
|
* and the DSA key wasn't much better:
|
|
*
|
|
* `dl-modp{sign{dsa-nist-sha1},dh{plain}}'
|
|
*
|
|
* It isn't clear that these will always be the same. I think it
|
|
* might be wise just to look at the `if-modn{sign{rsa' and
|
|
* `dl-modp{sign{dsa' prefixes.
|
|
*
|
|
* Finally, the encryption. The cipher-type string appears to be
|
|
* either `none' or `3des-cbc'. Looks as if this is SSH-2-style
|
|
* 3des-cbc (i.e. outer cbc rather than inner). The key is created
|
|
* from the passphrase by means of yet another hashing faff:
|
|
*
|
|
* - first 16 bytes are MD5(passphrase)
|
|
* - next 16 bytes are MD5(passphrase || first 16 bytes)
|
|
* - if there were more, they'd be MD5(passphrase || first 32),
|
|
* and so on.
|
|
*/
|
|
|
|
#define SSHCOM_MAGIC_NUMBER 0x3f6ff9eb
|
|
|
|
struct sshcom_key {
|
|
char comment[256]; /* allowing any length is overkill */
|
|
unsigned char *keyblob;
|
|
int keyblob_len, keyblob_size;
|
|
};
|
|
|
|
static struct sshcom_key *load_sshcom_key(const Filename *filename,
|
|
const char **errmsg_p)
|
|
{
|
|
struct sshcom_key *ret;
|
|
FILE *fp;
|
|
char *line = NULL;
|
|
int hdrstart, len;
|
|
const char *errmsg;
|
|
char *p;
|
|
int headers_done;
|
|
char base64_bit[4];
|
|
int base64_chars = 0;
|
|
|
|
ret = snew(struct sshcom_key);
|
|
ret->comment[0] = '\0';
|
|
ret->keyblob = NULL;
|
|
ret->keyblob_len = ret->keyblob_size = 0;
|
|
|
|
fp = f_open(filename, "r", FALSE);
|
|
if (!fp) {
|
|
errmsg = "unable to open key file";
|
|
goto error;
|
|
}
|
|
if (!(line = fgetline(fp))) {
|
|
errmsg = "unexpected end of file";
|
|
goto error;
|
|
}
|
|
strip_crlf(line);
|
|
if (0 != strcmp(line, "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----")) {
|
|
errmsg = "file does not begin with ssh.com key header";
|
|
goto error;
|
|
}
|
|
smemclr(line, strlen(line));
|
|
sfree(line);
|
|
line = NULL;
|
|
|
|
headers_done = 0;
|
|
while (1) {
|
|
if (!(line = fgetline(fp))) {
|
|
errmsg = "unexpected end of file";
|
|
goto error;
|
|
}
|
|
strip_crlf(line);
|
|
if (!strcmp(line, "---- END SSH2 ENCRYPTED PRIVATE KEY ----")) {
|
|
sfree(line);
|
|
line = NULL;
|
|
break; /* done */
|
|
}
|
|
if ((p = strchr(line, ':')) != NULL) {
|
|
if (headers_done) {
|
|
errmsg = "header found in body of key data";
|
|
goto error;
|
|
}
|
|
*p++ = '\0';
|
|
while (*p && isspace((unsigned char)*p)) p++;
|
|
hdrstart = p - line;
|
|
|
|
/*
|
|
* Header lines can end in a trailing backslash for
|
|
* continuation.
|
|
*/
|
|
len = hdrstart + strlen(line+hdrstart);
|
|
assert(!line[len]);
|
|
while (line[len-1] == '\\') {
|
|
char *line2;
|
|
int line2len;
|
|
|
|
line2 = fgetline(fp);
|
|
if (!line2) {
|
|
errmsg = "unexpected end of file";
|
|
goto error;
|
|
}
|
|
strip_crlf(line2);
|
|
|
|
line2len = strlen(line2);
|
|
line = sresize(line, len + line2len + 1, char);
|
|
strcpy(line + len - 1, line2);
|
|
len += line2len - 1;
|
|
assert(!line[len]);
|
|
|
|
smemclr(line2, strlen(line2));
|
|
sfree(line2);
|
|
line2 = NULL;
|
|
}
|
|
p = line + hdrstart;
|
|
strip_crlf(p);
|
|
if (!strcmp(line, "Comment")) {
|
|
/* Strip quotes in comment if present. */
|
|
if (p[0] == '"' && p[strlen(p)-1] == '"') {
|
|
p++;
|
|
p[strlen(p)-1] = '\0';
|
|
}
|
|
strncpy(ret->comment, p, sizeof(ret->comment));
|
|
ret->comment[sizeof(ret->comment)-1] = '\0';
|
|
}
|
|
} else {
|
|
headers_done = 1;
|
|
|
|
p = line;
|
|
while (isbase64(*p)) {
|
|
base64_bit[base64_chars++] = *p;
|
|
if (base64_chars == 4) {
|
|
unsigned char out[3];
|
|
|
|
base64_chars = 0;
|
|
|
|
len = base64_decode_atom(base64_bit, out);
|
|
|
|
if (len <= 0) {
|
|
errmsg = "invalid base64 encoding";
|
|
goto error;
|
|
}
|
|
|
|
if (ret->keyblob_len + len > ret->keyblob_size) {
|
|
ret->keyblob_size = ret->keyblob_len + len + 256;
|
|
ret->keyblob = sresize(ret->keyblob, ret->keyblob_size,
|
|
unsigned char);
|
|
}
|
|
|
|
memcpy(ret->keyblob + ret->keyblob_len, out, len);
|
|
ret->keyblob_len += len;
|
|
}
|
|
|
|
p++;
|
|
}
|
|
}
|
|
smemclr(line, strlen(line));
|
|
sfree(line);
|
|
line = NULL;
|
|
}
|
|
|
|
if (ret->keyblob_len == 0 || !ret->keyblob) {
|
|
errmsg = "key body not present";
|
|
goto error;
|
|
}
|
|
|
|
fclose(fp);
|
|
if (errmsg_p) *errmsg_p = NULL;
|
|
return ret;
|
|
|
|
error:
|
|
if (fp)
|
|
fclose(fp);
|
|
|
|
if (line) {
|
|
smemclr(line, strlen(line));
|
|
sfree(line);
|
|
line = NULL;
|
|
}
|
|
if (ret) {
|
|
if (ret->keyblob) {
|
|
smemclr(ret->keyblob, ret->keyblob_size);
|
|
sfree(ret->keyblob);
|
|
}
|
|
smemclr(ret, sizeof(*ret));
|
|
sfree(ret);
|
|
}
|
|
if (errmsg_p) *errmsg_p = errmsg;
|
|
return NULL;
|
|
}
|
|
|
|
int sshcom_encrypted(const Filename *filename, char **comment)
|
|
{
|
|
struct sshcom_key *key = load_sshcom_key(filename, NULL);
|
|
int pos, len, answer;
|
|
|
|
answer = 0;
|
|
|
|
*comment = NULL;
|
|
if (!key)
|
|
goto done;
|
|
|
|
/*
|
|
* Check magic number.
|
|
*/
|
|
if (GET_32BIT(key->keyblob) != 0x3f6ff9eb) {
|
|
goto done; /* key is invalid */
|
|
}
|
|
|
|
/*
|
|
* Find the cipher-type string.
|
|
*/
|
|
pos = 8;
|
|
if (key->keyblob_len < pos+4)
|
|
goto done; /* key is far too short */
|
|
len = toint(GET_32BIT(key->keyblob + pos));
|
|
if (len < 0 || len > key->keyblob_len - pos - 4)
|
|
goto done; /* key is far too short */
|
|
pos += 4 + len; /* skip key type */
|
|
len = toint(GET_32BIT(key->keyblob + pos)); /* find cipher-type length */
|
|
if (len < 0 || len > key->keyblob_len - pos - 4)
|
|
goto done; /* cipher type string is incomplete */
|
|
if (len != 4 || 0 != memcmp(key->keyblob + pos + 4, "none", 4))
|
|
answer = 1;
|
|
|
|
done:
|
|
if (key) {
|
|
*comment = dupstr(key->comment);
|
|
smemclr(key->keyblob, key->keyblob_size);
|
|
sfree(key->keyblob);
|
|
smemclr(key, sizeof(*key));
|
|
sfree(key);
|
|
} else {
|
|
*comment = dupstr("");
|
|
}
|
|
return answer;
|
|
}
|
|
|
|
static int sshcom_read_mpint(void *data, int len, struct mpint_pos *ret)
|
|
{
|
|
unsigned bits, bytes;
|
|
unsigned char *d = (unsigned char *) data;
|
|
|
|
if (len < 4)
|
|
goto error;
|
|
bits = GET_32BIT(d);
|
|
|
|
bytes = (bits + 7) / 8;
|
|
if (len < 4+bytes)
|
|
goto error;
|
|
|
|
ret->start = d + 4;
|
|
ret->bytes = bytes;
|
|
return bytes+4;
|
|
|
|
error:
|
|
ret->start = NULL;
|
|
ret->bytes = -1;
|
|
return len; /* ensure further calls fail as well */
|
|
}
|
|
|
|
static int sshcom_put_mpint(void *target, void *data, int len)
|
|
{
|
|
unsigned char *d = (unsigned char *)target;
|
|
unsigned char *i = (unsigned char *)data;
|
|
int bits = len * 8 - 1;
|
|
|
|
while (bits > 0) {
|
|
if (*i & (1 << (bits & 7)))
|
|
break;
|
|
if (!(bits-- & 7))
|
|
i++, len--;
|
|
}
|
|
|
|
PUT_32BIT(d, bits+1);
|
|
memcpy(d+4, i, len);
|
|
return len+4;
|
|
}
|
|
|
|
struct ssh2_userkey *sshcom_read(const Filename *filename, char *passphrase,
|
|
const char **errmsg_p)
|
|
{
|
|
struct sshcom_key *key = load_sshcom_key(filename, errmsg_p);
|
|
const char *errmsg;
|
|
int pos, len;
|
|
const char prefix_rsa[] = "if-modn{sign{rsa";
|
|
const char prefix_dsa[] = "dl-modp{sign{dsa";
|
|
enum { RSA, DSA } type;
|
|
int encrypted;
|
|
char *ciphertext;
|
|
int cipherlen;
|
|
struct ssh2_userkey *ret = NULL, *retkey;
|
|
const struct ssh_signkey *alg;
|
|
unsigned char *blob = NULL;
|
|
int blobsize = 0, publen, privlen;
|
|
|
|
if (!key)
|
|
return NULL;
|
|
|
|
/*
|
|
* Check magic number.
|
|
*/
|
|
if (GET_32BIT(key->keyblob) != SSHCOM_MAGIC_NUMBER) {
|
|
errmsg = "key does not begin with magic number";
|
|
goto error;
|
|
}
|
|
|
|
/*
|
|
* Determine the key type.
|
|
*/
|
|
pos = 8;
|
|
if (key->keyblob_len < pos+4 ||
|
|
(len = toint(GET_32BIT(key->keyblob + pos))) < 0 ||
|
|
len > key->keyblob_len - pos - 4) {
|
|
errmsg = "key blob does not contain a key type string";
|
|
goto error;
|
|
}
|
|
if (len > sizeof(prefix_rsa) - 1 &&
|
|
!memcmp(key->keyblob+pos+4, prefix_rsa, sizeof(prefix_rsa) - 1)) {
|
|
type = RSA;
|
|
} else if (len > sizeof(prefix_dsa) - 1 &&
|
|
!memcmp(key->keyblob+pos+4, prefix_dsa, sizeof(prefix_dsa) - 1)) {
|
|
type = DSA;
|
|
} else {
|
|
errmsg = "key is of unknown type";
|
|
goto error;
|
|
}
|
|
pos += 4+len;
|
|
|
|
/*
|
|
* Determine the cipher type.
|
|
*/
|
|
if (key->keyblob_len < pos+4 ||
|
|
(len = toint(GET_32BIT(key->keyblob + pos))) < 0 ||
|
|
len > key->keyblob_len - pos - 4) {
|
|
errmsg = "key blob does not contain a cipher type string";
|
|
goto error;
|
|
}
|
|
if (len == 4 && !memcmp(key->keyblob+pos+4, "none", 4))
|
|
encrypted = 0;
|
|
else if (len == 8 && !memcmp(key->keyblob+pos+4, "3des-cbc", 8))
|
|
encrypted = 1;
|
|
else {
|
|
errmsg = "key encryption is of unknown type";
|
|
goto error;
|
|
}
|
|
pos += 4+len;
|
|
|
|
/*
|
|
* Get hold of the encrypted part of the key.
|
|
*/
|
|
if (key->keyblob_len < pos+4 ||
|
|
(len = toint(GET_32BIT(key->keyblob + pos))) < 0 ||
|
|
len > key->keyblob_len - pos - 4) {
|
|
errmsg = "key blob does not contain actual key data";
|
|
goto error;
|
|
}
|
|
ciphertext = (char *)key->keyblob + pos + 4;
|
|
cipherlen = len;
|
|
if (cipherlen == 0) {
|
|
errmsg = "length of key data is zero";
|
|
goto error;
|
|
}
|
|
|
|
/*
|
|
* Decrypt it if necessary.
|
|
*/
|
|
if (encrypted) {
|
|
/*
|
|
* Derive encryption key from passphrase and iv/salt:
|
|
*
|
|
* - let block A equal MD5(passphrase)
|
|
* - let block B equal MD5(passphrase || A)
|
|
* - block C would be MD5(passphrase || A || B) and so on
|
|
* - encryption key is the first N bytes of A || B
|
|
*/
|
|
struct MD5Context md5c;
|
|
unsigned char keybuf[32], iv[8];
|
|
|
|
if (cipherlen % 8 != 0) {
|
|
errmsg = "encrypted part of key is not a multiple of cipher block"
|
|
" size";
|
|
goto error;
|
|
}
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
|
|
MD5Final(keybuf, &md5c);
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
|
|
MD5Update(&md5c, keybuf, 16);
|
|
MD5Final(keybuf+16, &md5c);
|
|
|
|
/*
|
|
* Now decrypt the key blob.
|
|
*/
|
|
memset(iv, 0, sizeof(iv));
|
|
des3_decrypt_pubkey_ossh(keybuf, iv, (unsigned char *)ciphertext,
|
|
cipherlen);
|
|
|
|
smemclr(&md5c, sizeof(md5c));
|
|
smemclr(keybuf, sizeof(keybuf));
|
|
|
|
/*
|
|
* Hereafter we return WRONG_PASSPHRASE for any parsing
|
|
* error. (But only if we've just tried to decrypt it!
|
|
* Returning WRONG_PASSPHRASE for an unencrypted key is
|
|
* automatic doom.)
|
|
*/
|
|
if (encrypted)
|
|
ret = SSH2_WRONG_PASSPHRASE;
|
|
}
|
|
|
|
/*
|
|
* Strip away the containing string to get to the real meat.
|
|
*/
|
|
len = toint(GET_32BIT(ciphertext));
|
|
if (len < 0 || len > cipherlen-4) {
|
|
errmsg = "containing string was ill-formed";
|
|
goto error;
|
|
}
|
|
ciphertext += 4;
|
|
cipherlen = len;
|
|
|
|
/*
|
|
* Now we break down into RSA versus DSA. In either case we'll
|
|
* construct public and private blobs in our own format, and
|
|
* end up feeding them to alg->createkey().
|
|
*/
|
|
blobsize = cipherlen + 256;
|
|
blob = snewn(blobsize, unsigned char);
|
|
privlen = 0;
|
|
if (type == RSA) {
|
|
struct mpint_pos n, e, d, u, p, q;
|
|
int pos = 0;
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &e);
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &d);
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &n);
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &u);
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &p);
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &q);
|
|
if (!q.start) {
|
|
errmsg = "key data did not contain six integers";
|
|
goto error;
|
|
}
|
|
|
|
alg = &ssh_rsa;
|
|
pos = 0;
|
|
pos += put_string(blob+pos, "ssh-rsa", 7);
|
|
pos += put_mp(blob+pos, e.start, e.bytes);
|
|
pos += put_mp(blob+pos, n.start, n.bytes);
|
|
publen = pos;
|
|
pos += put_string(blob+pos, d.start, d.bytes);
|
|
pos += put_mp(blob+pos, q.start, q.bytes);
|
|
pos += put_mp(blob+pos, p.start, p.bytes);
|
|
pos += put_mp(blob+pos, u.start, u.bytes);
|
|
privlen = pos - publen;
|
|
} else {
|
|
struct mpint_pos p, q, g, x, y;
|
|
int pos = 4;
|
|
|
|
assert(type == DSA); /* the only other option from the if above */
|
|
|
|
if (GET_32BIT(ciphertext) != 0) {
|
|
errmsg = "predefined DSA parameters not supported";
|
|
goto error;
|
|
}
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &p);
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &g);
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &q);
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &y);
|
|
pos += sshcom_read_mpint(ciphertext+pos, cipherlen-pos, &x);
|
|
if (!x.start) {
|
|
errmsg = "key data did not contain five integers";
|
|
goto error;
|
|
}
|
|
|
|
alg = &ssh_dss;
|
|
pos = 0;
|
|
pos += put_string(blob+pos, "ssh-dss", 7);
|
|
pos += put_mp(blob+pos, p.start, p.bytes);
|
|
pos += put_mp(blob+pos, q.start, q.bytes);
|
|
pos += put_mp(blob+pos, g.start, g.bytes);
|
|
pos += put_mp(blob+pos, y.start, y.bytes);
|
|
publen = pos;
|
|
pos += put_mp(blob+pos, x.start, x.bytes);
|
|
privlen = pos - publen;
|
|
}
|
|
|
|
assert(privlen > 0); /* should have bombed by now if not */
|
|
|
|
retkey = snew(struct ssh2_userkey);
|
|
retkey->alg = alg;
|
|
retkey->data = alg->createkey(alg, blob, publen, blob+publen, privlen);
|
|
if (!retkey->data) {
|
|
sfree(retkey);
|
|
errmsg = "unable to create key data structure";
|
|
goto error;
|
|
}
|
|
retkey->comment = dupstr(key->comment);
|
|
|
|
errmsg = NULL; /* no error */
|
|
ret = retkey;
|
|
|
|
error:
|
|
if (blob) {
|
|
smemclr(blob, blobsize);
|
|
sfree(blob);
|
|
}
|
|
smemclr(key->keyblob, key->keyblob_size);
|
|
sfree(key->keyblob);
|
|
smemclr(key, sizeof(*key));
|
|
sfree(key);
|
|
if (errmsg_p) *errmsg_p = errmsg;
|
|
return ret;
|
|
}
|
|
|
|
int sshcom_write(const Filename *filename, struct ssh2_userkey *key,
|
|
char *passphrase)
|
|
{
|
|
unsigned char *pubblob, *privblob;
|
|
int publen, privlen;
|
|
unsigned char *outblob;
|
|
int outlen;
|
|
struct mpint_pos numbers[6];
|
|
int nnumbers, initial_zero, pos, lenpos, i;
|
|
const char *type;
|
|
char *ciphertext;
|
|
int cipherlen;
|
|
int ret = 0;
|
|
FILE *fp;
|
|
|
|
/*
|
|
* Fetch the key blobs.
|
|
*/
|
|
pubblob = key->alg->public_blob(key->data, &publen);
|
|
privblob = key->alg->private_blob(key->data, &privlen);
|
|
outblob = NULL;
|
|
|
|
/*
|
|
* Find the sequence of integers to be encoded into the OpenSSH
|
|
* key blob, and also decide on the header line.
|
|
*/
|
|
if (key->alg == &ssh_rsa) {
|
|
int pos;
|
|
struct mpint_pos n, e, d, p, q, iqmp;
|
|
|
|
/*
|
|
* These blobs were generated from inside PuTTY, so we needn't
|
|
* treat them as untrusted.
|
|
*/
|
|
pos = 4 + GET_32BIT(pubblob);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &e);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &n);
|
|
pos = 0;
|
|
pos += ssh2_read_mpint(privblob+pos, privlen-pos, &d);
|
|
pos += ssh2_read_mpint(privblob+pos, privlen-pos, &p);
|
|
pos += ssh2_read_mpint(privblob+pos, privlen-pos, &q);
|
|
pos += ssh2_read_mpint(privblob+pos, privlen-pos, &iqmp);
|
|
|
|
assert(e.start && iqmp.start); /* can't go wrong */
|
|
|
|
numbers[0] = e;
|
|
numbers[1] = d;
|
|
numbers[2] = n;
|
|
numbers[3] = iqmp;
|
|
numbers[4] = q;
|
|
numbers[5] = p;
|
|
|
|
nnumbers = 6;
|
|
initial_zero = 0;
|
|
type = "if-modn{sign{rsa-pkcs1-sha1},encrypt{rsa-pkcs1v2-oaep}}";
|
|
} else if (key->alg == &ssh_dss) {
|
|
int pos;
|
|
struct mpint_pos p, q, g, y, x;
|
|
|
|
/*
|
|
* These blobs were generated from inside PuTTY, so we needn't
|
|
* treat them as untrusted.
|
|
*/
|
|
pos = 4 + GET_32BIT(pubblob);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &p);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &q);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &g);
|
|
pos += ssh2_read_mpint(pubblob+pos, publen-pos, &y);
|
|
pos = 0;
|
|
pos += ssh2_read_mpint(privblob+pos, privlen-pos, &x);
|
|
|
|
assert(y.start && x.start); /* can't go wrong */
|
|
|
|
numbers[0] = p;
|
|
numbers[1] = g;
|
|
numbers[2] = q;
|
|
numbers[3] = y;
|
|
numbers[4] = x;
|
|
|
|
nnumbers = 5;
|
|
initial_zero = 1;
|
|
type = "dl-modp{sign{dsa-nist-sha1},dh{plain}}";
|
|
} else {
|
|
assert(0); /* zoinks! */
|
|
exit(1); /* XXX: GCC doesn't understand assert() on some systems. */
|
|
}
|
|
|
|
/*
|
|
* Total size of key blob will be somewhere under 512 plus
|
|
* combined length of integers. We'll calculate the more
|
|
* precise size as we construct the blob.
|
|
*/
|
|
outlen = 512;
|
|
for (i = 0; i < nnumbers; i++)
|
|
outlen += 4 + numbers[i].bytes;
|
|
outblob = snewn(outlen, unsigned char);
|
|
|
|
/*
|
|
* Create the unencrypted key blob.
|
|
*/
|
|
pos = 0;
|
|
PUT_32BIT(outblob+pos, SSHCOM_MAGIC_NUMBER); pos += 4;
|
|
pos += 4; /* length field, fill in later */
|
|
pos += put_string(outblob+pos, type, strlen(type));
|
|
{
|
|
const char *ciphertype = passphrase ? "3des-cbc" : "none";
|
|
pos += put_string(outblob+pos, ciphertype, strlen(ciphertype));
|
|
}
|
|
lenpos = pos; /* remember this position */
|
|
pos += 4; /* encrypted-blob size */
|
|
pos += 4; /* encrypted-payload size */
|
|
if (initial_zero) {
|
|
PUT_32BIT(outblob+pos, 0);
|
|
pos += 4;
|
|
}
|
|
for (i = 0; i < nnumbers; i++)
|
|
pos += sshcom_put_mpint(outblob+pos,
|
|
numbers[i].start, numbers[i].bytes);
|
|
/* Now wrap up the encrypted payload. */
|
|
PUT_32BIT(outblob+lenpos+4, pos - (lenpos+8));
|
|
/* Pad encrypted blob to a multiple of cipher block size. */
|
|
if (passphrase) {
|
|
int padding = -(pos - (lenpos+4)) & 7;
|
|
while (padding--)
|
|
outblob[pos++] = random_byte();
|
|
}
|
|
ciphertext = (char *)outblob+lenpos+4;
|
|
cipherlen = pos - (lenpos+4);
|
|
assert(!passphrase || cipherlen % 8 == 0);
|
|
/* Wrap up the encrypted blob string. */
|
|
PUT_32BIT(outblob+lenpos, cipherlen);
|
|
/* And finally fill in the total length field. */
|
|
PUT_32BIT(outblob+4, pos);
|
|
|
|
assert(pos < outlen);
|
|
|
|
/*
|
|
* Encrypt the key.
|
|
*/
|
|
if (passphrase) {
|
|
/*
|
|
* Derive encryption key from passphrase and iv/salt:
|
|
*
|
|
* - let block A equal MD5(passphrase)
|
|
* - let block B equal MD5(passphrase || A)
|
|
* - block C would be MD5(passphrase || A || B) and so on
|
|
* - encryption key is the first N bytes of A || B
|
|
*/
|
|
struct MD5Context md5c;
|
|
unsigned char keybuf[32], iv[8];
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
|
|
MD5Final(keybuf, &md5c);
|
|
|
|
MD5Init(&md5c);
|
|
MD5Update(&md5c, (unsigned char *)passphrase, strlen(passphrase));
|
|
MD5Update(&md5c, keybuf, 16);
|
|
MD5Final(keybuf+16, &md5c);
|
|
|
|
/*
|
|
* Now decrypt the key blob.
|
|
*/
|
|
memset(iv, 0, sizeof(iv));
|
|
des3_encrypt_pubkey_ossh(keybuf, iv, (unsigned char *)ciphertext,
|
|
cipherlen);
|
|
|
|
smemclr(&md5c, sizeof(md5c));
|
|
smemclr(keybuf, sizeof(keybuf));
|
|
}
|
|
|
|
/*
|
|
* And save it. We'll use Unix line endings just in case it's
|
|
* subsequently transferred in binary mode.
|
|
*/
|
|
fp = f_open(filename, "wb", TRUE); /* ensure Unix line endings */
|
|
if (!fp)
|
|
goto error;
|
|
fputs("---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----\n", fp);
|
|
fprintf(fp, "Comment: \"");
|
|
/*
|
|
* Comment header is broken with backslash-newline if it goes
|
|
* over 70 chars. Although it's surrounded by quotes, it
|
|
* _doesn't_ escape backslashes or quotes within the string.
|
|
* Don't ask me, I didn't design it.
|
|
*/
|
|
{
|
|
int slen = 60; /* starts at 60 due to "Comment: " */
|
|
char *c = key->comment;
|
|
while ((int)strlen(c) > slen) {
|
|
fprintf(fp, "%.*s\\\n", slen, c);
|
|
c += slen;
|
|
slen = 70; /* allow 70 chars on subsequent lines */
|
|
}
|
|
fprintf(fp, "%s\"\n", c);
|
|
}
|
|
base64_encode(fp, outblob, pos, 70);
|
|
fputs("---- END SSH2 ENCRYPTED PRIVATE KEY ----\n", fp);
|
|
fclose(fp);
|
|
ret = 1;
|
|
|
|
error:
|
|
if (outblob) {
|
|
smemclr(outblob, outlen);
|
|
sfree(outblob);
|
|
}
|
|
if (privblob) {
|
|
smemclr(privblob, privlen);
|
|
sfree(privblob);
|
|
}
|
|
if (pubblob) {
|
|
smemclr(pubblob, publen);
|
|
sfree(pubblob);
|
|
}
|
|
return ret;
|
|
}
|