2008-05-07 13:39:42 +00:00

596 lines
14 KiB
C

/*
* Copyright (c) 2006 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "ntlm/ntlm.h"
RCSID("$Id: crypto.c 19535 2006-12-28 14:49:01Z lha $");
uint32_t
_krb5_crc_update (const char *p, size_t len, uint32_t res);
void
_krb5_crc_init_table(void);
/*
*
*/
static void
encode_le_uint32(uint32_t n, unsigned char *p)
{
p[0] = (n >> 0) & 0xFF;
p[1] = (n >> 8) & 0xFF;
p[2] = (n >> 16) & 0xFF;
p[3] = (n >> 24) & 0xFF;
}
static void
decode_le_uint32(const void *ptr, uint32_t *n)
{
const unsigned char *p = ptr;
*n = (p[0] << 0) | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
}
/*
*
*/
const char a2i_signmagic[] =
"session key to server-to-client signing key magic constant";
const char a2i_sealmagic[] =
"session key to server-to-client sealing key magic constant";
const char i2a_signmagic[] =
"session key to client-to-server signing key magic constant";
const char i2a_sealmagic[] =
"session key to client-to-server sealing key magic constant";
void
_gss_ntlm_set_key(struct ntlmv2_key *key, int acceptor, int sealsign,
unsigned char *data, size_t len)
{
unsigned char out[16];
MD5_CTX ctx;
const char *signmagic;
const char *sealmagic;
if (acceptor) {
signmagic = a2i_signmagic;
sealmagic = a2i_sealmagic;
} else {
signmagic = i2a_signmagic;
sealmagic = i2a_sealmagic;
}
key->seq = 0;
MD5_Init(&ctx);
MD5_Update(&ctx, data, len);
MD5_Update(&ctx, signmagic, strlen(signmagic) + 1);
MD5_Final(key->signkey, &ctx);
MD5_Init(&ctx);
MD5_Update(&ctx, data, len);
MD5_Update(&ctx, sealmagic, strlen(sealmagic) + 1);
MD5_Final(out, &ctx);
RC4_set_key(&key->sealkey, 16, out);
if (sealsign)
key->signsealkey = &key->sealkey;
}
/*
*
*/
static OM_uint32
v1_sign_message(gss_buffer_t in,
RC4_KEY *signkey,
uint32_t seq,
unsigned char out[16])
{
unsigned char sigature[12];
uint32_t crc;
_krb5_crc_init_table();
crc = _krb5_crc_update(in->value, in->length, 0);
encode_le_uint32(0, &sigature[0]);
encode_le_uint32(crc, &sigature[4]);
encode_le_uint32(seq, &sigature[8]);
encode_le_uint32(1, out); /* version */
RC4(signkey, sizeof(sigature), sigature, out + 4);
if (RAND_bytes(out + 4, 4) != 1)
return GSS_S_UNAVAILABLE;
return 0;
}
static OM_uint32
v2_sign_message(gss_buffer_t in,
unsigned char signkey[16],
RC4_KEY *sealkey,
uint32_t seq,
unsigned char out[16])
{
unsigned char hmac[16];
unsigned int hmaclen;
HMAC_CTX c;
HMAC_CTX_init(&c);
HMAC_Init_ex(&c, signkey, 16, EVP_md5(), NULL);
encode_le_uint32(seq, hmac);
HMAC_Update(&c, hmac, 4);
HMAC_Update(&c, in->value, in->length);
HMAC_Final(&c, hmac, &hmaclen);
HMAC_CTX_cleanup(&c);
encode_le_uint32(1, &out[0]);
if (sealkey)
RC4(sealkey, 8, hmac, &out[4]);
else
memcpy(&out[4], hmac, 8);
memset(&out[12], 0, 4);
return GSS_S_COMPLETE;
}
static OM_uint32
v2_verify_message(gss_buffer_t in,
unsigned char signkey[16],
RC4_KEY *sealkey,
uint32_t seq,
const unsigned char checksum[16])
{
OM_uint32 ret;
unsigned char out[16];
ret = v2_sign_message(in, signkey, sealkey, seq, out);
if (ret)
return ret;
if (memcmp(checksum, out, 16) != 0)
return GSS_S_BAD_MIC;
return GSS_S_COMPLETE;
}
static OM_uint32
v2_seal_message(const gss_buffer_t in,
unsigned char signkey[16],
uint32_t seq,
RC4_KEY *sealkey,
gss_buffer_t out)
{
unsigned char *p;
OM_uint32 ret;
if (in->length + 16 < in->length)
return EINVAL;
p = malloc(in->length + 16);
if (p == NULL)
return ENOMEM;
RC4(sealkey, in->length, in->value, p);
ret = v2_sign_message(in, signkey, sealkey, seq, &p[in->length]);
if (ret) {
free(p);
return ret;
}
out->value = p;
out->length = in->length + 16;
return 0;
}
static OM_uint32
v2_unseal_message(gss_buffer_t in,
unsigned char signkey[16],
uint32_t seq,
RC4_KEY *sealkey,
gss_buffer_t out)
{
OM_uint32 ret;
if (in->length < 16)
return GSS_S_BAD_MIC;
out->length = in->length - 16;
out->value = malloc(out->length);
if (out->value == NULL)
return GSS_S_BAD_MIC;
RC4(sealkey, out->length, in->value, out->value);
ret = v2_verify_message(out, signkey, sealkey, seq,
((const unsigned char *)in->value) + out->length);
if (ret) {
OM_uint32 junk;
gss_release_buffer(&junk, out);
}
return ret;
}
/*
*
*/
#define CTX_FLAGS_ISSET(_ctx,_flags) \
(((_ctx)->flags & (_flags)) == (_flags))
/*
*
*/
OM_uint32 _gss_ntlm_get_mic
(OM_uint32 * minor_status,
const gss_ctx_id_t context_handle,
gss_qop_t qop_req,
const gss_buffer_t message_buffer,
gss_buffer_t message_token
)
{
ntlm_ctx ctx = (ntlm_ctx)context_handle;
OM_uint32 junk;
if (minor_status)
*minor_status = 0;
if (message_token) {
message_token->length = 0;
message_token->value = NULL;
}
message_token->value = malloc(16);
message_token->length = 16;
if (message_token->value == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
if (CTX_FLAGS_ISSET(ctx, NTLM_NEG_SIGN|NTLM_NEG_NTLM2_SESSION)) {
OM_uint32 ret;
if ((ctx->status & STATUS_SESSIONKEY) == 0) {
gss_release_buffer(&junk, message_token);
return GSS_S_UNAVAILABLE;
}
ret = v2_sign_message(message_buffer,
ctx->u.v2.send.signkey,
ctx->u.v2.send.signsealkey,
ctx->u.v2.send.seq++,
message_token->value);
if (ret)
gss_release_buffer(&junk, message_token);
return ret;
} else if (CTX_FLAGS_ISSET(ctx, NTLM_NEG_SIGN)) {
OM_uint32 ret;
if ((ctx->status & STATUS_SESSIONKEY) == 0) {
gss_release_buffer(&junk, message_token);
return GSS_S_UNAVAILABLE;
}
ret = v1_sign_message(message_buffer,
&ctx->u.v1.crypto_send.key,
ctx->u.v1.crypto_send.seq++,
message_token->value);
if (ret)
gss_release_buffer(&junk, message_token);
return ret;
} else if (CTX_FLAGS_ISSET(ctx, NTLM_NEG_ALWAYS_SIGN)) {
unsigned char *sigature;
sigature = message_token->value;
encode_le_uint32(1, &sigature[0]); /* version */
encode_le_uint32(0, &sigature[4]);
encode_le_uint32(0, &sigature[8]);
encode_le_uint32(0, &sigature[12]);
return GSS_S_COMPLETE;
}
gss_release_buffer(&junk, message_token);
return GSS_S_UNAVAILABLE;
}
/*
*
*/
OM_uint32
_gss_ntlm_verify_mic
(OM_uint32 * minor_status,
const gss_ctx_id_t context_handle,
const gss_buffer_t message_buffer,
const gss_buffer_t token_buffer,
gss_qop_t * qop_state
)
{
ntlm_ctx ctx = (ntlm_ctx)context_handle;
if (qop_state != NULL)
*qop_state = GSS_C_QOP_DEFAULT;
*minor_status = 0;
if (token_buffer->length != 16)
return GSS_S_BAD_MIC;
if (CTX_FLAGS_ISSET(ctx, NTLM_NEG_SIGN|NTLM_NEG_NTLM2_SESSION)) {
OM_uint32 ret;
if ((ctx->status & STATUS_SESSIONKEY) == 0)
return GSS_S_UNAVAILABLE;
ret = v2_verify_message(message_buffer,
ctx->u.v2.recv.signkey,
ctx->u.v2.recv.signsealkey,
ctx->u.v2.recv.seq++,
token_buffer->value);
if (ret)
return ret;
return GSS_S_COMPLETE;
} else if (CTX_FLAGS_ISSET(ctx, NTLM_NEG_SIGN)) {
unsigned char sigature[12];
uint32_t crc, num;
if ((ctx->status & STATUS_SESSIONKEY) == 0)
return GSS_S_UNAVAILABLE;
decode_le_uint32(token_buffer->value, &num);
if (num != 1)
return GSS_S_BAD_MIC;
RC4(&ctx->u.v1.crypto_recv.key, sizeof(sigature),
((unsigned char *)token_buffer->value) + 4, sigature);
_krb5_crc_init_table();
crc = _krb5_crc_update(message_buffer->value,
message_buffer->length, 0);
/* skip first 4 bytes in the encrypted checksum */
decode_le_uint32(&sigature[4], &num);
if (num != crc)
return GSS_S_BAD_MIC;
decode_le_uint32(&sigature[8], &num);
if (ctx->u.v1.crypto_recv.seq != num)
return GSS_S_BAD_MIC;
ctx->u.v1.crypto_recv.seq++;
return GSS_S_COMPLETE;
} else if (ctx->flags & NTLM_NEG_ALWAYS_SIGN) {
uint32_t num;
unsigned char *p;
p = (unsigned char*)(token_buffer->value);
decode_le_uint32(&p[0], &num); /* version */
if (num != 1) return GSS_S_BAD_MIC;
decode_le_uint32(&p[4], &num);
if (num != 0) return GSS_S_BAD_MIC;
decode_le_uint32(&p[8], &num);
if (num != 0) return GSS_S_BAD_MIC;
decode_le_uint32(&p[12], &num);
if (num != 0) return GSS_S_BAD_MIC;
return GSS_S_COMPLETE;
}
return GSS_S_UNAVAILABLE;
}
/*
*
*/
OM_uint32
_gss_ntlm_wrap_size_limit (
OM_uint32 * minor_status,
const gss_ctx_id_t context_handle,
int conf_req_flag,
gss_qop_t qop_req,
OM_uint32 req_output_size,
OM_uint32 * max_input_size
)
{
ntlm_ctx ctx = (ntlm_ctx)context_handle;
*minor_status = 0;
if(ctx->flags & NTLM_NEG_SEAL) {
if (req_output_size < 16)
*max_input_size = 0;
else
*max_input_size = req_output_size - 16;
return GSS_S_COMPLETE;
}
return GSS_S_UNAVAILABLE;
}
/*
*
*/
OM_uint32 _gss_ntlm_wrap
(OM_uint32 * minor_status,
const gss_ctx_id_t context_handle,
int conf_req_flag,
gss_qop_t qop_req,
const gss_buffer_t input_message_buffer,
int * conf_state,
gss_buffer_t output_message_buffer
)
{
ntlm_ctx ctx = (ntlm_ctx)context_handle;
OM_uint32 ret;
if (minor_status)
*minor_status = 0;
if (conf_state)
*conf_state = 0;
if (output_message_buffer == GSS_C_NO_BUFFER)
return GSS_S_FAILURE;
if (CTX_FLAGS_ISSET(ctx, NTLM_NEG_SEAL|NTLM_NEG_NTLM2_SESSION)) {
return v2_seal_message(input_message_buffer,
ctx->u.v2.send.signkey,
ctx->u.v2.send.seq++,
&ctx->u.v2.send.sealkey,
output_message_buffer);
} else if (CTX_FLAGS_ISSET(ctx, NTLM_NEG_SEAL)) {
gss_buffer_desc trailer;
OM_uint32 junk;
output_message_buffer->length = input_message_buffer->length + 16;
output_message_buffer->value = malloc(output_message_buffer->length);
if (output_message_buffer->value == NULL) {
output_message_buffer->length = 0;
return GSS_S_FAILURE;
}
RC4(&ctx->u.v1.crypto_send.key, input_message_buffer->length,
input_message_buffer->value, output_message_buffer->value);
ret = _gss_ntlm_get_mic(minor_status, context_handle,
0, input_message_buffer,
&trailer);
if (ret) {
gss_release_buffer(&junk, output_message_buffer);
return ret;
}
if (trailer.length != 16) {
gss_release_buffer(&junk, output_message_buffer);
gss_release_buffer(&junk, &trailer);
return GSS_S_FAILURE;
}
memcpy(((unsigned char *)output_message_buffer->value) +
input_message_buffer->length,
trailer.value, trailer.length);
gss_release_buffer(&junk, &trailer);
return GSS_S_COMPLETE;
}
return GSS_S_UNAVAILABLE;
}
/*
*
*/
OM_uint32 _gss_ntlm_unwrap
(OM_uint32 * minor_status,
const gss_ctx_id_t context_handle,
const gss_buffer_t input_message_buffer,
gss_buffer_t output_message_buffer,
int * conf_state,
gss_qop_t * qop_state
)
{
ntlm_ctx ctx = (ntlm_ctx)context_handle;
OM_uint32 ret;
if (minor_status)
*minor_status = 0;
if (output_message_buffer) {
output_message_buffer->value = NULL;
output_message_buffer->length = 0;
}
if (conf_state)
*conf_state = 0;
if (qop_state)
*qop_state = 0;
if (CTX_FLAGS_ISSET(ctx, NTLM_NEG_SEAL|NTLM_NEG_NTLM2_SESSION)) {
return v2_unseal_message(input_message_buffer,
ctx->u.v2.recv.signkey,
ctx->u.v2.recv.seq++,
&ctx->u.v2.recv.sealkey,
output_message_buffer);
} else if (CTX_FLAGS_ISSET(ctx, NTLM_NEG_SEAL)) {
gss_buffer_desc trailer;
OM_uint32 junk;
if (input_message_buffer->length < 16)
return GSS_S_BAD_MIC;
output_message_buffer->length = input_message_buffer->length - 16;
output_message_buffer->value = malloc(output_message_buffer->length);
if (output_message_buffer->value == NULL) {
output_message_buffer->length = 0;
return GSS_S_FAILURE;
}
RC4(&ctx->u.v1.crypto_recv.key, output_message_buffer->length,
input_message_buffer->value, output_message_buffer->value);
trailer.value = ((unsigned char *)input_message_buffer->value) +
output_message_buffer->length;
trailer.length = 16;
ret = _gss_ntlm_verify_mic(minor_status, context_handle,
output_message_buffer,
&trailer, NULL);
if (ret) {
gss_release_buffer(&junk, output_message_buffer);
return ret;
}
return GSS_S_COMPLETE;
}
return GSS_S_UNAVAILABLE;
}