1999-01-08 16:02:13 +03:00
|
|
|
/*
|
|
|
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* RSA implementation just sufficient for ssh client-side
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|
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* initialisation step
|
1999-07-06 23:38:54 +04:00
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*
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* Rewritten for more speed by Joris van Rantwijk, Jun 1999.
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1999-01-08 16:02:13 +03:00
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
|
2001-03-03 14:54:34 +03:00
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#include <assert.h>
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1999-01-08 16:02:13 +03:00
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2000-09-05 18:28:17 +04:00
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#include "ssh.h"
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2002-01-01 19:51:03 +03:00
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#include "misc.h"
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1999-01-08 16:02:13 +03:00
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2001-12-30 18:58:17 +03:00
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#define GET_32BIT(cp) \
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(((unsigned long)(unsigned char)(cp)[0] << 24) | \
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((unsigned long)(unsigned char)(cp)[1] << 16) | \
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((unsigned long)(unsigned char)(cp)[2] << 8) | \
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((unsigned long)(unsigned char)(cp)[3]))
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#define PUT_32BIT(cp, value) { \
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(cp)[0] = (unsigned char)((value) >> 24); \
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(cp)[1] = (unsigned char)((value) >> 16); \
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(cp)[2] = (unsigned char)((value) >> 8); \
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(cp)[3] = (unsigned char)(value); }
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2000-09-26 18:26:21 +04:00
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1999-01-08 16:02:13 +03:00
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int makekey(unsigned char *data, struct RSAKey *result,
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2001-05-06 18:35:20 +04:00
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unsigned char **keystr, int order)
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{
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1999-01-08 16:02:13 +03:00
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unsigned char *p = data;
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2000-09-07 20:33:49 +04:00
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int i;
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1999-01-08 16:02:13 +03:00
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2000-09-25 14:14:53 +04:00
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if (result) {
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2001-05-06 18:35:20 +04:00
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result->bits = 0;
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for (i = 0; i < 4; i++)
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result->bits = (result->bits << 8) + *p++;
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2000-09-25 14:14:53 +04:00
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} else
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2001-05-06 18:35:20 +04:00
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p += 4;
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1999-01-08 16:02:13 +03:00
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2000-09-07 20:33:49 +04:00
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/*
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* order=0 means exponent then modulus (the keys sent by the
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* server). order=1 means modulus then exponent (the keys
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* stored in a keyfile).
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*/
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1999-01-08 16:02:13 +03:00
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2000-09-07 20:33:49 +04:00
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if (order == 0)
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2001-05-06 18:35:20 +04:00
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p += ssh1_read_bignum(p, result ? &result->exponent : NULL);
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2000-09-25 14:14:53 +04:00
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if (result)
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2001-05-06 18:35:20 +04:00
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result->bytes = (((p[0] << 8) + p[1]) + 7) / 8;
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if (keystr)
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*keystr = p + 2;
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2000-09-25 14:14:53 +04:00
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p += ssh1_read_bignum(p, result ? &result->modulus : NULL);
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2000-09-07 20:33:49 +04:00
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if (order == 1)
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2001-05-06 18:35:20 +04:00
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p += ssh1_read_bignum(p, result ? &result->exponent : NULL);
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1999-01-08 16:02:13 +03:00
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return p - data;
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}
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2001-05-06 18:35:20 +04:00
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int makeprivate(unsigned char *data, struct RSAKey *result)
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{
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2000-09-07 20:33:49 +04:00
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return ssh1_read_bignum(data, &result->private_exponent);
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}
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2001-05-06 18:35:20 +04:00
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void rsaencrypt(unsigned char *data, int length, struct RSAKey *key)
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{
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1999-01-08 16:02:13 +03:00
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Bignum b1, b2;
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2001-03-01 20:41:26 +03:00
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int i;
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1999-01-08 16:02:13 +03:00
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unsigned char *p;
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2001-05-06 18:35:20 +04:00
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memmove(data + key->bytes - length, data, length);
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1999-01-08 16:02:13 +03:00
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data[0] = 0;
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data[1] = 2;
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2001-05-06 18:35:20 +04:00
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for (i = 2; i < key->bytes - length - 1; i++) {
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1999-01-08 16:02:13 +03:00
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do {
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data[i] = random_byte();
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} while (data[i] == 0);
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}
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2001-05-06 18:35:20 +04:00
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data[key->bytes - length - 1] = 0;
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1999-01-08 16:02:13 +03:00
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|
2001-03-01 20:41:26 +03:00
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b1 = bignum_from_bytes(data, key->bytes);
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1999-01-08 16:02:13 +03:00
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2000-10-23 20:11:31 +04:00
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b2 = modpow(b1, key->exponent, key->modulus);
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1999-01-08 16:02:13 +03:00
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p = data;
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2001-05-06 18:35:20 +04:00
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for (i = key->bytes; i--;) {
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*p++ = bignum_byte(b2, i);
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1999-01-08 16:02:13 +03:00
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}
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freebn(b1);
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freebn(b2);
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}
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2001-05-06 18:35:20 +04:00
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Bignum rsadecrypt(Bignum input, struct RSAKey *key)
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{
|
2000-09-07 20:33:49 +04:00
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Bignum ret;
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2000-10-23 20:11:31 +04:00
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ret = modpow(input, key->private_exponent, key->modulus);
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2000-09-07 20:33:49 +04:00
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return ret;
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}
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2001-05-06 18:35:20 +04:00
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int rsastr_len(struct RSAKey *key)
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{
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1999-01-08 16:02:13 +03:00
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Bignum md, ex;
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2001-03-01 20:41:26 +03:00
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int mdlen, exlen;
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1999-01-08 16:02:13 +03:00
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md = key->modulus;
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ex = key->exponent;
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2001-05-06 18:35:20 +04:00
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mdlen = (bignum_bitcount(md) + 15) / 16;
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exlen = (bignum_bitcount(ex) + 15) / 16;
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return 4 * (mdlen + exlen) + 20;
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1999-01-08 16:02:13 +03:00
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}
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2001-05-06 18:35:20 +04:00
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void rsastr_fmt(char *str, struct RSAKey *key)
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{
|
1999-01-08 16:02:13 +03:00
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|
Bignum md, ex;
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2000-09-27 19:21:04 +04:00
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int len = 0, i, nibbles;
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static const char hex[] = "0123456789abcdef";
|
1999-01-08 16:02:13 +03:00
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md = key->modulus;
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ex = key->exponent;
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2001-05-06 18:35:20 +04:00
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len += sprintf(str + len, "0x");
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2000-09-27 19:21:04 +04:00
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2001-05-06 18:35:20 +04:00
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nibbles = (3 + bignum_bitcount(ex)) / 4;
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if (nibbles < 1)
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nibbles = 1;
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for (i = nibbles; i--;)
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str[len++] = hex[(bignum_byte(ex, i / 2) >> (4 * (i % 2))) & 0xF];
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2000-09-27 19:21:04 +04:00
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2001-05-06 18:35:20 +04:00
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len += sprintf(str + len, ",0x");
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2000-09-27 19:21:04 +04:00
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2001-05-06 18:35:20 +04:00
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nibbles = (3 + bignum_bitcount(md)) / 4;
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if (nibbles < 1)
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nibbles = 1;
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for (i = nibbles; i--;)
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str[len++] = hex[(bignum_byte(md, i / 2) >> (4 * (i % 2))) & 0xF];
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2000-09-27 19:21:04 +04:00
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1999-01-08 16:02:13 +03:00
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str[len] = '\0';
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}
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2000-09-26 18:26:21 +04:00
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/*
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* Generate a fingerprint string for the key. Compatible with the
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* OpenSSH fingerprint code.
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*/
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2001-05-06 18:35:20 +04:00
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void rsa_fingerprint(char *str, int len, struct RSAKey *key)
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{
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2000-09-26 18:26:21 +04:00
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struct MD5Context md5c;
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unsigned char digest[16];
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2001-05-06 18:35:20 +04:00
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char buffer[16 * 3 + 40];
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2000-09-26 18:26:21 +04:00
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int numlen, slen, i;
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MD5Init(&md5c);
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numlen = ssh1_bignum_length(key->modulus) - 2;
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2001-05-06 18:35:20 +04:00
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for (i = numlen; i--;) {
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unsigned char c = bignum_byte(key->modulus, i);
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MD5Update(&md5c, &c, 1);
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2000-09-26 18:26:21 +04:00
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}
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numlen = ssh1_bignum_length(key->exponent) - 2;
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2001-05-06 18:35:20 +04:00
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for (i = numlen; i--;) {
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unsigned char c = bignum_byte(key->exponent, i);
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MD5Update(&md5c, &c, 1);
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2000-09-26 18:26:21 +04:00
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}
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MD5Final(digest, &md5c);
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2001-04-16 15:16:58 +04:00
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sprintf(buffer, "%d ", bignum_bitcount(key->modulus));
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2000-09-26 18:26:21 +04:00
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for (i = 0; i < 16; i++)
|
2001-05-06 18:35:20 +04:00
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sprintf(buffer + strlen(buffer), "%s%02x", i ? ":" : "",
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digest[i]);
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strncpy(str, buffer, len);
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str[len - 1] = '\0';
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2000-09-26 18:26:21 +04:00
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slen = strlen(str);
|
2001-05-06 18:35:20 +04:00
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|
if (key->comment && slen < len - 1) {
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str[slen] = ' ';
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strncpy(str + slen + 1, key->comment, len - slen - 1);
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str[len - 1] = '\0';
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2000-09-26 18:26:21 +04:00
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}
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}
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2001-03-23 00:48:33 +03:00
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/*
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|
|
* Verify that the public data in an RSA key matches the private
|
2001-03-23 16:02:39 +03:00
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* data. We also check the private data itself: we ensure that p >
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* q and that iqmp really is the inverse of q mod p.
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2001-03-23 00:48:33 +03:00
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*/
|
2001-05-06 18:35:20 +04:00
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int rsa_verify(struct RSAKey *key)
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{
|
2001-03-23 16:02:39 +03:00
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Bignum n, ed, pm1, qm1;
|
2001-03-23 00:48:33 +03:00
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int cmp;
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/* n must equal pq. */
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n = bigmul(key->p, key->q);
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cmp = bignum_cmp(n, key->modulus);
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freebn(n);
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if (cmp != 0)
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return 0;
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|
2001-03-23 16:02:39 +03:00
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/* e * d must be congruent to 1, modulo (p-1) and modulo (q-1). */
|
2001-03-23 00:48:33 +03:00
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pm1 = copybn(key->p);
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decbn(pm1);
|
2001-03-23 16:02:39 +03:00
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ed = modmul(key->exponent, key->private_exponent, pm1);
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cmp = bignum_cmp(ed, One);
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sfree(ed);
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if (cmp != 0)
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return 0;
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|
2001-03-23 00:48:33 +03:00
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qm1 = copybn(key->q);
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decbn(qm1);
|
2001-03-23 16:02:39 +03:00
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ed = modmul(key->exponent, key->private_exponent, qm1);
|
2001-03-23 00:48:33 +03:00
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cmp = bignum_cmp(ed, One);
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sfree(ed);
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if (cmp != 0)
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return 0;
|
2001-03-23 12:20:43 +03:00
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2001-03-23 16:02:39 +03:00
|
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/*
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* Ensure p > q.
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|
|
*/
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if (bignum_cmp(key->p, key->q) <= 0)
|
2001-05-06 18:35:20 +04:00
|
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|
return 0;
|
2001-03-23 16:02:39 +03:00
|
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|
|
|
|
/*
|
|
|
|
* Ensure iqmp * q is congruent to 1, modulo p.
|
|
|
|
*/
|
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|
n = modmul(key->iqmp, key->q, key->p);
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cmp = bignum_cmp(n, One);
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|
sfree(n);
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|
if (cmp != 0)
|
2001-05-06 18:35:20 +04:00
|
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|
return 0;
|
2001-03-23 16:02:39 +03:00
|
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|
2001-03-23 12:20:43 +03:00
|
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|
return 1;
|
2001-03-23 00:48:33 +03:00
|
|
|
}
|
|
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|
|
2001-12-30 18:58:17 +03:00
|
|
|
/* Public key blob as used by Pageant: exponent before modulus. */
|
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|
|
unsigned char *rsa_public_blob(struct RSAKey *key, int *len)
|
|
|
|
{
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|
|
int length, pos;
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|
unsigned char *ret;
|
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|
|
|
|
|
|
length = (ssh1_bignum_length(key->modulus) +
|
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|
|
ssh1_bignum_length(key->exponent) + 4);
|
|
|
|
ret = smalloc(length);
|
|
|
|
|
|
|
|
PUT_32BIT(ret, bignum_bitcount(key->modulus));
|
|
|
|
pos = 4;
|
|
|
|
pos += ssh1_write_bignum(ret + pos, key->exponent);
|
|
|
|
pos += ssh1_write_bignum(ret + pos, key->modulus);
|
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|
|
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|
|
*len = length;
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Given a public blob, determine its length. */
|
|
|
|
int rsa_public_blob_len(void *data)
|
|
|
|
{
|
|
|
|
unsigned char *p = (unsigned char *)data;
|
|
|
|
|
|
|
|
p += 4; /* length word */
|
|
|
|
p += ssh1_read_bignum(p, NULL); /* exponent */
|
|
|
|
p += ssh1_read_bignum(p, NULL); /* modulus */
|
|
|
|
|
|
|
|
return p - (unsigned char *)data;
|
|
|
|
}
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
void freersakey(struct RSAKey *key)
|
|
|
|
{
|
|
|
|
if (key->modulus)
|
|
|
|
freebn(key->modulus);
|
|
|
|
if (key->exponent)
|
|
|
|
freebn(key->exponent);
|
|
|
|
if (key->private_exponent)
|
|
|
|
freebn(key->private_exponent);
|
|
|
|
if (key->comment)
|
|
|
|
sfree(key->comment);
|
2000-09-14 19:02:50 +04:00
|
|
|
}
|
2001-03-02 20:13:36 +03:00
|
|
|
|
|
|
|
/* ----------------------------------------------------------------------
|
|
|
|
* Implementation of the ssh-rsa signing key type.
|
|
|
|
*/
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
static void getstring(char **data, int *datalen, char **p, int *length)
|
|
|
|
{
|
2001-03-02 20:13:36 +03:00
|
|
|
*p = NULL;
|
|
|
|
if (*datalen < 4)
|
2001-05-06 18:35:20 +04:00
|
|
|
return;
|
2001-03-02 20:13:36 +03:00
|
|
|
*length = GET_32BIT(*data);
|
2001-05-06 18:35:20 +04:00
|
|
|
*datalen -= 4;
|
|
|
|
*data += 4;
|
2001-03-02 20:13:36 +03:00
|
|
|
if (*datalen < *length)
|
2001-05-06 18:35:20 +04:00
|
|
|
return;
|
2001-03-02 20:13:36 +03:00
|
|
|
*p = *data;
|
2001-05-06 18:35:20 +04:00
|
|
|
*data += *length;
|
|
|
|
*datalen -= *length;
|
2001-03-02 20:13:36 +03:00
|
|
|
}
|
2001-05-06 18:35:20 +04:00
|
|
|
static Bignum getmp(char **data, int *datalen)
|
|
|
|
{
|
2001-03-02 20:13:36 +03:00
|
|
|
char *p;
|
|
|
|
int length;
|
|
|
|
Bignum b;
|
|
|
|
|
|
|
|
getstring(data, datalen, &p, &length);
|
|
|
|
if (!p)
|
2001-05-06 18:35:20 +04:00
|
|
|
return NULL;
|
2001-03-02 20:13:36 +03:00
|
|
|
b = bignum_from_bytes(p, length);
|
|
|
|
return b;
|
|
|
|
}
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
static void *rsa2_newkey(char *data, int len)
|
|
|
|
{
|
2001-03-02 20:13:36 +03:00
|
|
|
char *p;
|
|
|
|
int slen;
|
|
|
|
struct RSAKey *rsa;
|
|
|
|
|
|
|
|
rsa = smalloc(sizeof(struct RSAKey));
|
2001-05-06 18:35:20 +04:00
|
|
|
if (!rsa)
|
|
|
|
return NULL;
|
2001-03-02 20:13:36 +03:00
|
|
|
getstring(&data, &len, &p, &slen);
|
|
|
|
|
2001-03-03 18:31:35 +03:00
|
|
|
if (!p || slen != 7 || memcmp(p, "ssh-rsa", 7)) {
|
2001-03-02 20:13:36 +03:00
|
|
|
sfree(rsa);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
rsa->exponent = getmp(&data, &len);
|
|
|
|
rsa->modulus = getmp(&data, &len);
|
|
|
|
rsa->private_exponent = NULL;
|
|
|
|
rsa->comment = NULL;
|
|
|
|
|
|
|
|
return rsa;
|
|
|
|
}
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
static void rsa2_freekey(void *key)
|
|
|
|
{
|
|
|
|
struct RSAKey *rsa = (struct RSAKey *) key;
|
2001-03-02 20:13:36 +03:00
|
|
|
freersakey(rsa);
|
|
|
|
sfree(rsa);
|
|
|
|
}
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
static char *rsa2_fmtkey(void *key)
|
|
|
|
{
|
|
|
|
struct RSAKey *rsa = (struct RSAKey *) key;
|
2001-03-02 20:13:36 +03:00
|
|
|
char *p;
|
|
|
|
int len;
|
2001-05-06 18:35:20 +04:00
|
|
|
|
2001-03-02 20:13:36 +03:00
|
|
|
len = rsastr_len(rsa);
|
|
|
|
p = smalloc(len);
|
2001-05-06 18:35:20 +04:00
|
|
|
rsastr_fmt(p, rsa);
|
2001-03-02 20:13:36 +03:00
|
|
|
return p;
|
|
|
|
}
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
static unsigned char *rsa2_public_blob(void *key, int *len)
|
|
|
|
{
|
|
|
|
struct RSAKey *rsa = (struct RSAKey *) key;
|
2001-03-03 14:54:34 +03:00
|
|
|
int elen, mlen, bloblen;
|
|
|
|
int i;
|
|
|
|
unsigned char *blob, *p;
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
elen = (bignum_bitcount(rsa->exponent) + 8) / 8;
|
|
|
|
mlen = (bignum_bitcount(rsa->modulus) + 8) / 8;
|
2001-03-03 14:54:34 +03:00
|
|
|
|
|
|
|
/*
|
|
|
|
* string "ssh-rsa", mpint exp, mpint mod. Total 19+elen+mlen.
|
|
|
|
* (three length fields, 12+7=19).
|
|
|
|
*/
|
2001-05-06 18:35:20 +04:00
|
|
|
bloblen = 19 + elen + mlen;
|
2001-03-03 14:54:34 +03:00
|
|
|
blob = smalloc(bloblen);
|
|
|
|
p = blob;
|
2001-05-06 18:35:20 +04:00
|
|
|
PUT_32BIT(p, 7);
|
|
|
|
p += 4;
|
|
|
|
memcpy(p, "ssh-rsa", 7);
|
|
|
|
p += 7;
|
|
|
|
PUT_32BIT(p, elen);
|
|
|
|
p += 4;
|
|
|
|
for (i = elen; i--;)
|
|
|
|
*p++ = bignum_byte(rsa->exponent, i);
|
|
|
|
PUT_32BIT(p, mlen);
|
|
|
|
p += 4;
|
|
|
|
for (i = mlen; i--;)
|
|
|
|
*p++ = bignum_byte(rsa->modulus, i);
|
2001-03-03 14:54:34 +03:00
|
|
|
assert(p == blob + bloblen);
|
|
|
|
*len = bloblen;
|
|
|
|
return blob;
|
|
|
|
}
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
static unsigned char *rsa2_private_blob(void *key, int *len)
|
|
|
|
{
|
|
|
|
struct RSAKey *rsa = (struct RSAKey *) key;
|
2001-03-03 14:54:34 +03:00
|
|
|
int dlen, plen, qlen, ulen, bloblen;
|
|
|
|
int i;
|
|
|
|
unsigned char *blob, *p;
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
dlen = (bignum_bitcount(rsa->private_exponent) + 8) / 8;
|
|
|
|
plen = (bignum_bitcount(rsa->p) + 8) / 8;
|
|
|
|
qlen = (bignum_bitcount(rsa->q) + 8) / 8;
|
|
|
|
ulen = (bignum_bitcount(rsa->iqmp) + 8) / 8;
|
2001-03-03 14:54:34 +03:00
|
|
|
|
|
|
|
/*
|
|
|
|
* mpint private_exp, mpint p, mpint q, mpint iqmp. Total 16 +
|
|
|
|
* sum of lengths.
|
|
|
|
*/
|
2001-05-06 18:35:20 +04:00
|
|
|
bloblen = 16 + dlen + plen + qlen + ulen;
|
2001-03-03 14:54:34 +03:00
|
|
|
blob = smalloc(bloblen);
|
|
|
|
p = blob;
|
2001-05-06 18:35:20 +04:00
|
|
|
PUT_32BIT(p, dlen);
|
|
|
|
p += 4;
|
|
|
|
for (i = dlen; i--;)
|
|
|
|
*p++ = bignum_byte(rsa->private_exponent, i);
|
|
|
|
PUT_32BIT(p, plen);
|
|
|
|
p += 4;
|
|
|
|
for (i = plen; i--;)
|
|
|
|
*p++ = bignum_byte(rsa->p, i);
|
|
|
|
PUT_32BIT(p, qlen);
|
|
|
|
p += 4;
|
|
|
|
for (i = qlen; i--;)
|
|
|
|
*p++ = bignum_byte(rsa->q, i);
|
|
|
|
PUT_32BIT(p, ulen);
|
|
|
|
p += 4;
|
|
|
|
for (i = ulen; i--;)
|
|
|
|
*p++ = bignum_byte(rsa->iqmp, i);
|
2001-03-03 14:54:34 +03:00
|
|
|
assert(p == blob + bloblen);
|
|
|
|
*len = bloblen;
|
|
|
|
return blob;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void *rsa2_createkey(unsigned char *pub_blob, int pub_len,
|
2001-05-06 18:35:20 +04:00
|
|
|
unsigned char *priv_blob, int priv_len)
|
|
|
|
{
|
2001-03-03 14:54:34 +03:00
|
|
|
struct RSAKey *rsa;
|
2001-05-06 18:35:20 +04:00
|
|
|
char *pb = (char *) priv_blob;
|
|
|
|
|
|
|
|
rsa = rsa2_newkey((char *) pub_blob, pub_len);
|
2001-03-03 14:54:34 +03:00
|
|
|
rsa->private_exponent = getmp(&pb, &priv_len);
|
|
|
|
rsa->p = getmp(&pb, &priv_len);
|
|
|
|
rsa->q = getmp(&pb, &priv_len);
|
|
|
|
rsa->iqmp = getmp(&pb, &priv_len);
|
|
|
|
|
2001-03-23 00:48:33 +03:00
|
|
|
if (!rsa_verify(rsa)) {
|
|
|
|
rsa2_freekey(rsa);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
2001-03-03 14:54:34 +03:00
|
|
|
return rsa;
|
|
|
|
}
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
static void *rsa2_openssh_createkey(unsigned char **blob, int *len)
|
|
|
|
{
|
|
|
|
char **b = (char **) blob;
|
2001-03-03 18:31:35 +03:00
|
|
|
struct RSAKey *rsa;
|
|
|
|
|
|
|
|
rsa = smalloc(sizeof(struct RSAKey));
|
2001-05-06 18:35:20 +04:00
|
|
|
if (!rsa)
|
|
|
|
return NULL;
|
2001-03-03 18:31:35 +03:00
|
|
|
rsa->comment = NULL;
|
|
|
|
|
|
|
|
rsa->modulus = getmp(b, len);
|
|
|
|
rsa->exponent = getmp(b, len);
|
|
|
|
rsa->private_exponent = getmp(b, len);
|
|
|
|
rsa->iqmp = getmp(b, len);
|
|
|
|
rsa->p = getmp(b, len);
|
|
|
|
rsa->q = getmp(b, len);
|
|
|
|
|
|
|
|
if (!rsa->modulus || !rsa->exponent || !rsa->private_exponent ||
|
|
|
|
!rsa->iqmp || !rsa->p || !rsa->q) {
|
|
|
|
sfree(rsa->modulus);
|
|
|
|
sfree(rsa->exponent);
|
|
|
|
sfree(rsa->private_exponent);
|
|
|
|
sfree(rsa->iqmp);
|
|
|
|
sfree(rsa->p);
|
|
|
|
sfree(rsa->q);
|
|
|
|
sfree(rsa);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
return rsa;
|
|
|
|
}
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
static int rsa2_openssh_fmtkey(void *key, unsigned char *blob, int len)
|
|
|
|
{
|
|
|
|
struct RSAKey *rsa = (struct RSAKey *) key;
|
2001-04-16 15:16:58 +04:00
|
|
|
int bloblen, i;
|
|
|
|
|
|
|
|
bloblen =
|
|
|
|
ssh2_bignum_length(rsa->modulus) +
|
|
|
|
ssh2_bignum_length(rsa->exponent) +
|
|
|
|
ssh2_bignum_length(rsa->private_exponent) +
|
|
|
|
ssh2_bignum_length(rsa->iqmp) +
|
2001-05-06 18:35:20 +04:00
|
|
|
ssh2_bignum_length(rsa->p) + ssh2_bignum_length(rsa->q);
|
2001-04-16 15:16:58 +04:00
|
|
|
|
|
|
|
if (bloblen > len)
|
|
|
|
return bloblen;
|
|
|
|
|
|
|
|
bloblen = 0;
|
|
|
|
#define ENC(x) \
|
|
|
|
PUT_32BIT(blob+bloblen, ssh2_bignum_length((x))-4); bloblen += 4; \
|
|
|
|
for (i = ssh2_bignum_length((x))-4; i-- ;) blob[bloblen++]=bignum_byte((x),i);
|
|
|
|
ENC(rsa->modulus);
|
|
|
|
ENC(rsa->exponent);
|
|
|
|
ENC(rsa->private_exponent);
|
|
|
|
ENC(rsa->iqmp);
|
|
|
|
ENC(rsa->p);
|
|
|
|
ENC(rsa->q);
|
|
|
|
|
|
|
|
return bloblen;
|
|
|
|
}
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
static char *rsa2_fingerprint(void *key)
|
|
|
|
{
|
|
|
|
struct RSAKey *rsa = (struct RSAKey *) key;
|
2001-03-02 20:13:36 +03:00
|
|
|
struct MD5Context md5c;
|
|
|
|
unsigned char digest[16], lenbuf[4];
|
2001-05-06 18:35:20 +04:00
|
|
|
char buffer[16 * 3 + 40];
|
2001-03-02 20:13:36 +03:00
|
|
|
char *ret;
|
|
|
|
int numlen, i;
|
|
|
|
|
|
|
|
MD5Init(&md5c);
|
|
|
|
MD5Update(&md5c, "\0\0\0\7ssh-rsa", 11);
|
|
|
|
|
|
|
|
#define ADD_BIGNUM(bignum) \
|
2001-04-16 15:16:58 +04:00
|
|
|
numlen = (bignum_bitcount(bignum)+8)/8; \
|
2001-03-02 20:13:36 +03:00
|
|
|
PUT_32BIT(lenbuf, numlen); MD5Update(&md5c, lenbuf, 4); \
|
|
|
|
for (i = numlen; i-- ;) { \
|
|
|
|
unsigned char c = bignum_byte(bignum, i); \
|
|
|
|
MD5Update(&md5c, &c, 1); \
|
|
|
|
}
|
|
|
|
ADD_BIGNUM(rsa->exponent);
|
|
|
|
ADD_BIGNUM(rsa->modulus);
|
|
|
|
#undef ADD_BIGNUM
|
|
|
|
|
|
|
|
MD5Final(digest, &md5c);
|
|
|
|
|
2001-04-16 15:16:58 +04:00
|
|
|
sprintf(buffer, "ssh-rsa %d ", bignum_bitcount(rsa->modulus));
|
2001-03-02 20:13:36 +03:00
|
|
|
for (i = 0; i < 16; i++)
|
2001-05-06 18:35:20 +04:00
|
|
|
sprintf(buffer + strlen(buffer), "%s%02x", i ? ":" : "",
|
|
|
|
digest[i]);
|
|
|
|
ret = smalloc(strlen(buffer) + 1);
|
2001-03-02 20:13:36 +03:00
|
|
|
if (ret)
|
2001-05-06 18:35:20 +04:00
|
|
|
strcpy(ret, buffer);
|
2001-03-02 20:13:36 +03:00
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* This is the magic ASN.1/DER prefix that goes in the decoded
|
|
|
|
* signature, between the string of FFs and the actual SHA hash
|
2001-03-09 16:30:43 +03:00
|
|
|
* value. The meaning of it is:
|
2001-03-02 20:13:36 +03:00
|
|
|
*
|
|
|
|
* 00 -- this marks the end of the FFs; not part of the ASN.1 bit itself
|
|
|
|
*
|
|
|
|
* 30 21 -- a constructed SEQUENCE of length 0x21
|
|
|
|
* 30 09 -- a constructed sub-SEQUENCE of length 9
|
|
|
|
* 06 05 -- an object identifier, length 5
|
2001-03-09 16:30:43 +03:00
|
|
|
* 2B 0E 03 02 1A -- object id { 1 3 14 3 2 26 }
|
|
|
|
* (the 1,3 comes from 0x2B = 43 = 40*1+3)
|
2001-03-02 20:13:36 +03:00
|
|
|
* 05 00 -- NULL
|
|
|
|
* 04 14 -- a primitive OCTET STRING of length 0x14
|
|
|
|
* [0x14 bytes of hash data follows]
|
2001-03-09 16:30:43 +03:00
|
|
|
*
|
|
|
|
* The object id in the middle there is listed as `id-sha1' in
|
|
|
|
* ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-1/pkcs-1v2-1d2.asn (the
|
|
|
|
* ASN module for PKCS #1) and its expanded form is as follows:
|
|
|
|
*
|
|
|
|
* id-sha1 OBJECT IDENTIFIER ::= {
|
|
|
|
* iso(1) identified-organization(3) oiw(14) secsig(3)
|
|
|
|
* algorithms(2) 26 }
|
2001-03-02 20:13:36 +03:00
|
|
|
*/
|
2002-10-25 16:59:57 +04:00
|
|
|
static const unsigned char asn1_weird_stuff[] = {
|
2001-05-06 18:35:20 +04:00
|
|
|
0x00, 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2B,
|
|
|
|
0x0E, 0x03, 0x02, 0x1A, 0x05, 0x00, 0x04, 0x14,
|
2001-03-02 20:13:36 +03:00
|
|
|
};
|
|
|
|
|
2001-03-05 20:31:36 +03:00
|
|
|
#define ASN1_LEN ( (int) sizeof(asn1_weird_stuff) )
|
|
|
|
|
2001-03-02 20:13:36 +03:00
|
|
|
static int rsa2_verifysig(void *key, char *sig, int siglen,
|
2001-05-06 18:35:20 +04:00
|
|
|
char *data, int datalen)
|
|
|
|
{
|
|
|
|
struct RSAKey *rsa = (struct RSAKey *) key;
|
2001-03-02 20:13:36 +03:00
|
|
|
Bignum in, out;
|
|
|
|
char *p;
|
|
|
|
int slen;
|
|
|
|
int bytes, i, j, ret;
|
|
|
|
unsigned char hash[20];
|
|
|
|
|
|
|
|
getstring(&sig, &siglen, &p, &slen);
|
|
|
|
if (!p || slen != 7 || memcmp(p, "ssh-rsa", 7)) {
|
2001-05-06 18:35:20 +04:00
|
|
|
return 0;
|
2001-03-02 20:13:36 +03:00
|
|
|
}
|
|
|
|
in = getmp(&sig, &siglen);
|
|
|
|
out = modpow(in, rsa->exponent, rsa->modulus);
|
|
|
|
freebn(in);
|
|
|
|
|
|
|
|
ret = 1;
|
|
|
|
|
2001-04-16 15:16:58 +04:00
|
|
|
bytes = bignum_bitcount(rsa->modulus) / 8;
|
2001-03-02 20:13:36 +03:00
|
|
|
/* Top (partial) byte should be zero. */
|
2001-05-06 18:35:20 +04:00
|
|
|
if (bignum_byte(out, bytes - 1) != 0)
|
|
|
|
ret = 0;
|
2001-03-02 20:13:36 +03:00
|
|
|
/* First whole byte should be 1. */
|
2001-05-06 18:35:20 +04:00
|
|
|
if (bignum_byte(out, bytes - 2) != 1)
|
|
|
|
ret = 0;
|
2001-03-02 20:13:36 +03:00
|
|
|
/* Most of the rest should be FF. */
|
2001-05-06 18:35:20 +04:00
|
|
|
for (i = bytes - 3; i >= 20 + ASN1_LEN; i--) {
|
|
|
|
if (bignum_byte(out, i) != 0xFF)
|
|
|
|
ret = 0;
|
2001-03-02 20:13:36 +03:00
|
|
|
}
|
|
|
|
/* Then we expect to see the asn1_weird_stuff. */
|
2001-05-06 18:35:20 +04:00
|
|
|
for (i = 20 + ASN1_LEN - 1, j = 0; i >= 20; i--, j++) {
|
|
|
|
if (bignum_byte(out, i) != asn1_weird_stuff[j])
|
|
|
|
ret = 0;
|
2001-03-02 20:13:36 +03:00
|
|
|
}
|
|
|
|
/* Finally, we expect to see the SHA-1 hash of the signed data. */
|
|
|
|
SHA_Simple(data, datalen, hash);
|
2001-05-06 18:35:20 +04:00
|
|
|
for (i = 19, j = 0; i >= 0; i--, j++) {
|
|
|
|
if (bignum_byte(out, i) != hash[j])
|
|
|
|
ret = 0;
|
2001-03-02 20:13:36 +03:00
|
|
|
}
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
unsigned char *rsa2_sign(void *key, char *data, int datalen, int *siglen)
|
|
|
|
{
|
|
|
|
struct RSAKey *rsa = (struct RSAKey *) key;
|
2001-03-03 14:54:34 +03:00
|
|
|
unsigned char *bytes;
|
|
|
|
int nbytes;
|
|
|
|
unsigned char hash[20];
|
|
|
|
Bignum in, out;
|
|
|
|
int i, j;
|
|
|
|
|
|
|
|
SHA_Simple(data, datalen, hash);
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
nbytes = (bignum_bitcount(rsa->modulus) - 1) / 8;
|
2001-03-03 14:54:34 +03:00
|
|
|
bytes = smalloc(nbytes);
|
|
|
|
|
|
|
|
bytes[0] = 1;
|
2001-05-06 18:35:20 +04:00
|
|
|
for (i = 1; i < nbytes - 20 - ASN1_LEN; i++)
|
2001-03-03 14:54:34 +03:00
|
|
|
bytes[i] = 0xFF;
|
2001-05-06 18:35:20 +04:00
|
|
|
for (i = nbytes - 20 - ASN1_LEN, j = 0; i < nbytes - 20; i++, j++)
|
2001-03-03 14:54:34 +03:00
|
|
|
bytes[i] = asn1_weird_stuff[j];
|
2001-05-06 18:35:20 +04:00
|
|
|
for (i = nbytes - 20, j = 0; i < nbytes; i++, j++)
|
2001-03-03 14:54:34 +03:00
|
|
|
bytes[i] = hash[j];
|
|
|
|
|
|
|
|
in = bignum_from_bytes(bytes, nbytes);
|
|
|
|
sfree(bytes);
|
|
|
|
|
|
|
|
out = modpow(in, rsa->private_exponent, rsa->modulus);
|
|
|
|
freebn(in);
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
nbytes = (bignum_bitcount(out) + 7) / 8;
|
|
|
|
bytes = smalloc(4 + 7 + 4 + nbytes);
|
2001-03-03 14:54:34 +03:00
|
|
|
PUT_32BIT(bytes, 7);
|
2001-05-06 18:35:20 +04:00
|
|
|
memcpy(bytes + 4, "ssh-rsa", 7);
|
|
|
|
PUT_32BIT(bytes + 4 + 7, nbytes);
|
2001-03-03 14:54:34 +03:00
|
|
|
for (i = 0; i < nbytes; i++)
|
2001-05-06 18:35:20 +04:00
|
|
|
bytes[4 + 7 + 4 + i] = bignum_byte(out, nbytes - 1 - i);
|
2001-03-03 14:54:34 +03:00
|
|
|
freebn(out);
|
|
|
|
|
2001-05-06 18:35:20 +04:00
|
|
|
*siglen = 4 + 7 + 4 + nbytes;
|
2001-03-03 14:54:34 +03:00
|
|
|
return bytes;
|
2001-03-02 20:13:36 +03:00
|
|
|
}
|
|
|
|
|
2001-03-03 14:54:34 +03:00
|
|
|
const struct ssh_signkey ssh_rsa = {
|
2001-03-02 20:13:36 +03:00
|
|
|
rsa2_newkey,
|
|
|
|
rsa2_freekey,
|
|
|
|
rsa2_fmtkey,
|
2001-03-03 14:54:34 +03:00
|
|
|
rsa2_public_blob,
|
|
|
|
rsa2_private_blob,
|
|
|
|
rsa2_createkey,
|
2001-03-03 18:31:35 +03:00
|
|
|
rsa2_openssh_createkey,
|
2001-04-16 15:16:58 +04:00
|
|
|
rsa2_openssh_fmtkey,
|
2001-03-02 20:13:36 +03:00
|
|
|
rsa2_fingerprint,
|
|
|
|
rsa2_verifysig,
|
|
|
|
rsa2_sign,
|
|
|
|
"ssh-rsa",
|
|
|
|
"rsa2"
|
|
|
|
};
|