putty/windows/wingss.c

481 строка
14 KiB
C

#ifndef NO_GSSAPI
#include "putty.h"
#include <security.h>
#include "pgssapi.h"
#include "sshgss.h"
#include "sshgssc.h"
#include "misc.h"
/* Windows code to set up the GSSAPI library list. */
const int ngsslibs = 3;
const char *const gsslibnames[3] = {
"MIT Kerberos GSSAPI32.DLL",
"Microsoft SSPI SECUR32.DLL",
"User-specified GSSAPI DLL",
};
const struct keyvalwhere gsslibkeywords[] = {
{ "gssapi32", 0, -1, -1 },
{ "sspi", 1, -1, -1 },
{ "custom", 2, -1, -1 },
};
DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS,
AcquireCredentialsHandleA,
(SEC_CHAR *, SEC_CHAR *, ULONG, PLUID,
PVOID, SEC_GET_KEY_FN, PVOID, PCredHandle, PTimeStamp));
DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS,
InitializeSecurityContextA,
(PCredHandle, PCtxtHandle, SEC_CHAR *, ULONG, ULONG,
ULONG, PSecBufferDesc, ULONG, PCtxtHandle,
PSecBufferDesc, PULONG, PTimeStamp));
DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS,
FreeContextBuffer,
(PVOID));
DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS,
FreeCredentialsHandle,
(PCredHandle));
DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS,
DeleteSecurityContext,
(PCtxtHandle));
DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS,
QueryContextAttributesA,
(PCtxtHandle, ULONG, PVOID));
DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS,
MakeSignature,
(PCtxtHandle, ULONG, PSecBufferDesc, ULONG));
typedef struct winSsh_gss_ctx {
unsigned long maj_stat;
unsigned long min_stat;
CredHandle cred_handle;
CtxtHandle context;
PCtxtHandle context_handle;
TimeStamp expiry;
} winSsh_gss_ctx;
const Ssh_gss_buf gss_mech_krb5={9,"\x2A\x86\x48\x86\xF7\x12\x01\x02\x02"};
const char *gsslogmsg = NULL;
static void ssh_sspi_bind_fns(struct ssh_gss_library *lib);
struct ssh_gss_liblist *ssh_gss_setup(Conf *conf)
{
HMODULE module;
HKEY regkey;
struct ssh_gss_liblist *list = snew(struct ssh_gss_liblist);
char *path;
list->libraries = snewn(3, struct ssh_gss_library);
list->nlibraries = 0;
/* MIT Kerberos GSSAPI implementation */
/* TODO: For 64-bit builds, check for gssapi64.dll */
module = NULL;
if (RegOpenKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\MIT\\Kerberos", &regkey)
== ERROR_SUCCESS) {
DWORD type, size;
LONG ret;
char *buffer;
/* Find out the string length */
ret = RegQueryValueEx(regkey, "InstallDir", NULL, &type, NULL, &size);
if (ret == ERROR_SUCCESS && type == REG_SZ) {
buffer = snewn(size + 20, char);
ret = RegQueryValueEx(regkey, "InstallDir", NULL,
&type, buffer, &size);
if (ret == ERROR_SUCCESS && type == REG_SZ) {
strcat(buffer, "\\bin\\gssapi32.dll");
module = LoadLibrary(buffer);
}
sfree(buffer);
}
RegCloseKey(regkey);
}
if (module) {
struct ssh_gss_library *lib =
&list->libraries[list->nlibraries++];
lib->id = 0;
lib->gsslogmsg = "Using GSSAPI from GSSAPI32.DLL";
lib->handle = (void *)module;
#define BIND_GSS_FN(name) \
lib->u.gssapi.name = (t_gss_##name) GetProcAddress(module, "gss_" #name)
BIND_GSS_FN(delete_sec_context);
BIND_GSS_FN(display_status);
BIND_GSS_FN(get_mic);
BIND_GSS_FN(import_name);
BIND_GSS_FN(init_sec_context);
BIND_GSS_FN(release_buffer);
BIND_GSS_FN(release_cred);
BIND_GSS_FN(release_name);
#undef BIND_GSS_FN
ssh_gssapi_bind_fns(lib);
}
/* Microsoft SSPI Implementation */
module = load_system32_dll("secur32.dll");
if (module) {
struct ssh_gss_library *lib =
&list->libraries[list->nlibraries++];
lib->id = 1;
lib->gsslogmsg = "Using SSPI from SECUR32.DLL";
lib->handle = (void *)module;
GET_WINDOWS_FUNCTION(module, AcquireCredentialsHandleA);
GET_WINDOWS_FUNCTION(module, InitializeSecurityContextA);
GET_WINDOWS_FUNCTION(module, FreeContextBuffer);
GET_WINDOWS_FUNCTION(module, FreeCredentialsHandle);
GET_WINDOWS_FUNCTION(module, DeleteSecurityContext);
GET_WINDOWS_FUNCTION(module, QueryContextAttributesA);
GET_WINDOWS_FUNCTION(module, MakeSignature);
ssh_sspi_bind_fns(lib);
}
/*
* Custom GSSAPI DLL.
*/
module = NULL;
path = conf_get_filename(conf, CONF_ssh_gss_custom)->path;
if (*path) {
module = LoadLibrary(path);
}
if (module) {
struct ssh_gss_library *lib =
&list->libraries[list->nlibraries++];
lib->id = 2;
lib->gsslogmsg = dupprintf("Using GSSAPI from user-specified"
" library '%s'", path);
lib->handle = (void *)module;
#define BIND_GSS_FN(name) \
lib->u.gssapi.name = (t_gss_##name) GetProcAddress(module, "gss_" #name)
BIND_GSS_FN(delete_sec_context);
BIND_GSS_FN(display_status);
BIND_GSS_FN(get_mic);
BIND_GSS_FN(import_name);
BIND_GSS_FN(init_sec_context);
BIND_GSS_FN(release_buffer);
BIND_GSS_FN(release_cred);
BIND_GSS_FN(release_name);
#undef BIND_GSS_FN
ssh_gssapi_bind_fns(lib);
}
return list;
}
void ssh_gss_cleanup(struct ssh_gss_liblist *list)
{
int i;
/*
* LoadLibrary and FreeLibrary are defined to employ reference
* counting in the case where the same library is repeatedly
* loaded, so even in a multiple-sessions-per-process context
* (not that we currently expect ever to have such a thing on
* Windows) it's safe to naively FreeLibrary everything here
* without worrying about destroying it under the feet of
* another SSH instance still using it.
*/
for (i = 0; i < list->nlibraries; i++) {
FreeLibrary((HMODULE)list->libraries[i].handle);
if (list->libraries[i].id == 2) {
/* The 'custom' id involves a dynamically allocated message.
* Note that we must cast away the 'const' to free it. */
sfree((char *)list->libraries[i].gsslogmsg);
}
}
sfree(list->libraries);
sfree(list);
}
static Ssh_gss_stat ssh_sspi_indicate_mech(struct ssh_gss_library *lib,
Ssh_gss_buf *mech)
{
*mech = gss_mech_krb5;
return SSH_GSS_OK;
}
static Ssh_gss_stat ssh_sspi_import_name(struct ssh_gss_library *lib,
char *host, Ssh_gss_name *srv_name)
{
char *pStr;
/* Check hostname */
if (host == NULL) return SSH_GSS_FAILURE;
/* copy it into form host/FQDN */
pStr = dupcat("host/", host, NULL);
*srv_name = (Ssh_gss_name) pStr;
return SSH_GSS_OK;
}
static Ssh_gss_stat ssh_sspi_acquire_cred(struct ssh_gss_library *lib,
Ssh_gss_ctx *ctx)
{
winSsh_gss_ctx *winctx = snew(winSsh_gss_ctx);
memset(winctx, 0, sizeof(winSsh_gss_ctx));
/* prepare our "wrapper" structure */
winctx->maj_stat = winctx->min_stat = SEC_E_OK;
winctx->context_handle = NULL;
/* Specifying no principal name here means use the credentials of
the current logged-in user */
winctx->maj_stat = p_AcquireCredentialsHandleA(NULL,
"Kerberos",
SECPKG_CRED_OUTBOUND,
NULL,
NULL,
NULL,
NULL,
&winctx->cred_handle,
&winctx->expiry);
if (winctx->maj_stat != SEC_E_OK) return SSH_GSS_FAILURE;
*ctx = (Ssh_gss_ctx) winctx;
return SSH_GSS_OK;
}
static Ssh_gss_stat ssh_sspi_init_sec_context(struct ssh_gss_library *lib,
Ssh_gss_ctx *ctx,
Ssh_gss_name srv_name,
int to_deleg,
Ssh_gss_buf *recv_tok,
Ssh_gss_buf *send_tok)
{
winSsh_gss_ctx *winctx = (winSsh_gss_ctx *) *ctx;
SecBuffer wsend_tok = {send_tok->length,SECBUFFER_TOKEN,send_tok->value};
SecBuffer wrecv_tok = {recv_tok->length,SECBUFFER_TOKEN,recv_tok->value};
SecBufferDesc output_desc={SECBUFFER_VERSION,1,&wsend_tok};
SecBufferDesc input_desc ={SECBUFFER_VERSION,1,&wrecv_tok};
unsigned long flags=ISC_REQ_MUTUAL_AUTH|ISC_REQ_REPLAY_DETECT|
ISC_REQ_CONFIDENTIALITY|ISC_REQ_ALLOCATE_MEMORY;
unsigned long ret_flags=0;
/* check if we have to delegate ... */
if (to_deleg) flags |= ISC_REQ_DELEGATE;
winctx->maj_stat = p_InitializeSecurityContextA(&winctx->cred_handle,
winctx->context_handle,
(char*) srv_name,
flags,
0, /* reserved */
SECURITY_NATIVE_DREP,
&input_desc,
0, /* reserved */
&winctx->context,
&output_desc,
&ret_flags,
&winctx->expiry);
/* prepare for the next round */
winctx->context_handle = &winctx->context;
send_tok->value = wsend_tok.pvBuffer;
send_tok->length = wsend_tok.cbBuffer;
/* check & return our status */
if (winctx->maj_stat==SEC_E_OK) return SSH_GSS_S_COMPLETE;
if (winctx->maj_stat==SEC_I_CONTINUE_NEEDED) return SSH_GSS_S_CONTINUE_NEEDED;
return SSH_GSS_FAILURE;
}
static Ssh_gss_stat ssh_sspi_free_tok(struct ssh_gss_library *lib,
Ssh_gss_buf *send_tok)
{
/* check input */
if (send_tok == NULL) return SSH_GSS_FAILURE;
/* free Windows buffer */
p_FreeContextBuffer(send_tok->value);
SSH_GSS_CLEAR_BUF(send_tok);
return SSH_GSS_OK;
}
static Ssh_gss_stat ssh_sspi_release_cred(struct ssh_gss_library *lib,
Ssh_gss_ctx *ctx)
{
winSsh_gss_ctx *winctx= (winSsh_gss_ctx *) *ctx;
/* check input */
if (winctx == NULL) return SSH_GSS_FAILURE;
/* free Windows data */
p_FreeCredentialsHandle(&winctx->cred_handle);
p_DeleteSecurityContext(&winctx->context);
/* delete our "wrapper" structure */
sfree(winctx);
*ctx = (Ssh_gss_ctx) NULL;
return SSH_GSS_OK;
}
static Ssh_gss_stat ssh_sspi_release_name(struct ssh_gss_library *lib,
Ssh_gss_name *srv_name)
{
char *pStr= (char *) *srv_name;
if (pStr == NULL) return SSH_GSS_FAILURE;
sfree(pStr);
*srv_name = (Ssh_gss_name) NULL;
return SSH_GSS_OK;
}
static Ssh_gss_stat ssh_sspi_display_status(struct ssh_gss_library *lib,
Ssh_gss_ctx ctx, Ssh_gss_buf *buf)
{
winSsh_gss_ctx *winctx = (winSsh_gss_ctx *) ctx;
char *msg;
if (winctx == NULL) return SSH_GSS_FAILURE;
/* decode the error code */
switch (winctx->maj_stat) {
case SEC_E_OK: msg="SSPI status OK"; break;
case SEC_E_INVALID_HANDLE: msg="The handle passed to the function"
" is invalid.";
break;
case SEC_E_TARGET_UNKNOWN: msg="The target was not recognized."; break;
case SEC_E_LOGON_DENIED: msg="The logon failed."; break;
case SEC_E_INTERNAL_ERROR: msg="The Local Security Authority cannot"
" be contacted.";
break;
case SEC_E_NO_CREDENTIALS: msg="No credentials are available in the"
" security package.";
break;
case SEC_E_NO_AUTHENTICATING_AUTHORITY:
msg="No authority could be contacted for authentication."
"The domain name of the authenticating party could be wrong,"
" the domain could be unreachable, or there might have been"
" a trust relationship failure.";
break;
case SEC_E_INSUFFICIENT_MEMORY:
msg="One or more of the SecBufferDesc structures passed as"
" an OUT parameter has a buffer that is too small.";
break;
case SEC_E_INVALID_TOKEN:
msg="The error is due to a malformed input token, such as a"
" token corrupted in transit, a token"
" of incorrect size, or a token passed into the wrong"
" security package. Passing a token to"
" the wrong package can happen if client and server did not"
" negotiate the proper security package.";
break;
default:
msg = "Internal SSPI error";
break;
}
buf->value = dupstr(msg);
buf->length = strlen(buf->value);
return SSH_GSS_OK;
}
static Ssh_gss_stat ssh_sspi_get_mic(struct ssh_gss_library *lib,
Ssh_gss_ctx ctx, Ssh_gss_buf *buf,
Ssh_gss_buf *hash)
{
winSsh_gss_ctx *winctx= (winSsh_gss_ctx *) ctx;
SecPkgContext_Sizes ContextSizes;
SecBufferDesc InputBufferDescriptor;
SecBuffer InputSecurityToken[2];
if (winctx == NULL) return SSH_GSS_FAILURE;
winctx->maj_stat = 0;
memset(&ContextSizes, 0, sizeof(ContextSizes));
winctx->maj_stat = p_QueryContextAttributesA(&winctx->context,
SECPKG_ATTR_SIZES,
&ContextSizes);
if (winctx->maj_stat != SEC_E_OK ||
ContextSizes.cbMaxSignature == 0)
return winctx->maj_stat;
InputBufferDescriptor.cBuffers = 2;
InputBufferDescriptor.pBuffers = InputSecurityToken;
InputBufferDescriptor.ulVersion = SECBUFFER_VERSION;
InputSecurityToken[0].BufferType = SECBUFFER_DATA;
InputSecurityToken[0].cbBuffer = buf->length;
InputSecurityToken[0].pvBuffer = buf->value;
InputSecurityToken[1].BufferType = SECBUFFER_TOKEN;
InputSecurityToken[1].cbBuffer = ContextSizes.cbMaxSignature;
InputSecurityToken[1].pvBuffer = snewn(ContextSizes.cbMaxSignature, char);
winctx->maj_stat = p_MakeSignature(&winctx->context,
0,
&InputBufferDescriptor,
0);
if (winctx->maj_stat == SEC_E_OK) {
hash->length = InputSecurityToken[1].cbBuffer;
hash->value = InputSecurityToken[1].pvBuffer;
}
return winctx->maj_stat;
}
static Ssh_gss_stat ssh_sspi_free_mic(struct ssh_gss_library *lib,
Ssh_gss_buf *hash)
{
sfree(hash->value);
return SSH_GSS_OK;
}
static void ssh_sspi_bind_fns(struct ssh_gss_library *lib)
{
lib->indicate_mech = ssh_sspi_indicate_mech;
lib->import_name = ssh_sspi_import_name;
lib->release_name = ssh_sspi_release_name;
lib->init_sec_context = ssh_sspi_init_sec_context;
lib->free_tok = ssh_sspi_free_tok;
lib->acquire_cred = ssh_sspi_acquire_cred;
lib->release_cred = ssh_sspi_release_cred;
lib->get_mic = ssh_sspi_get_mic;
lib->free_mic = ssh_sspi_free_mic;
lib->display_status = ssh_sspi_display_status;
}
#else
/* Dummy function so this source file defines something if NO_GSSAPI
is defined. */
void ssh_gss_init(void)
{
}
#endif