mirrors/FreeRDP
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

libfreerdp-core: added CredSSP

Browse Source
This commit is contained in:
Marc-André Moreau 2011-06-30 18:51:46 -04:00
parent 0dac2c555a
commit 61afc74d2e
2 changed files with 593 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

537
libfreerdp-core/credssp.c Normal file
View File

@ -0,0 +1,537 @@
/**
* FreeRDP: A Remote Desktop Protocol Client
* Credential Security Support Provider (CredSSP)
*
* Copyright 2010 Marc-Andre Moreau <marcandre.moreau@gmail.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "frdp.h"
#include "rdp.h"
#include "tls.h"
#include "asn1.h"
#include "security.h"
#include "stream.h"
#include "tcp.h"
#include "mcs.h"
#include "iso.h"
#ifndef _WIN32
#include <unistd.h>
#endif
#include "TSRequest.h"
#include "NegoData.h"
#include "NegotiationToken.h"
#include "TSCredentials.h"
#include "TSPasswordCreds.h"
#include <time.h>
#include "ntlmssp.h"
#include <freerdp/rdpset.h>
#include <freerdp/utils/memory.h>
#include "credssp.h"
static int
asn1_write(const void *buffer, size_t size, void *fd)
{
/* this is used to get the size of the ASN.1 encoded result */
return 0;
}
/**
* Initialize NTLMSSP authentication module.
* @param credssp
*/
void credssp_ntlmssp_init(rdpCredssp *credssp)
{
NTLMSSP *ntlmssp = credssp->ntlmssp;
rdpSet *settings = credssp->net->rdp->settings;
ntlmssp_set_password(ntlmssp, settings->password);
ntlmssp_set_username(ntlmssp, settings->username);
if (settings->domain != NULL)
{
if (strlen(settings->domain) > 0)
{
ntlmssp_set_domain(ntlmssp, settings->domain);
}
}
else
{
ntlmssp_set_domain(ntlmssp, NULL);
}
ntlmssp_generate_client_challenge(ntlmssp);
ntlmssp_generate_random_session_key(ntlmssp);
ntlmssp_generate_exported_session_key(ntlmssp);
ntlmssp->ntlm_v2 = 0;
}
/**
* Get TLS public key.
* @param credssp
*/
int credssp_get_public_key(rdpCredssp *credssp)
{
CryptoCert cert;
int ret;
cert = tls_get_certificate(credssp->net->tls);
if (cert == NULL)
{
printf("credssp_get_public_key: tls_get_certificate failed to return the server certificate.\n");
return 0;
}
ret = crypto_cert_get_public_key(cert, &credssp->public_key);
crypto_cert_free(cert);
return ret;
}
/**
* Authenticate with server using CredSSP.
* @param credssp
* @return 1 if authentication is successful
*/
int credssp_authenticate(rdpCredssp *credssp)
{
NTLMSSP *ntlmssp = credssp->ntlmssp;
STREAM s = xmalloc(sizeof(struct stream));
uint8* negoTokenBuffer = (uint8*) xmalloc(2048);
credssp_ntlmssp_init(credssp);
if (credssp_get_public_key(credssp) == 0)
return 0;
/* NTLMSSP NEGOTIATE MESSAGE */
s->p = s->end = s->data = negoTokenBuffer;
ntlmssp_send(ntlmssp, s);
credssp->negoToken.data = s->data;
credssp->negoToken.length = s->end - s->data;
credssp_send(credssp, &credssp->negoToken, NULL, NULL);
/* NTLMSSP CHALLENGE MESSAGE */
if (credssp_recv(credssp, &credssp->negoToken, NULL, NULL) < 0)
return -1;
s->p = s->data = credssp->negoToken.data;
s->end = s->p + credssp->negoToken.length;
ntlmssp_recv(ntlmssp, s);
datablob_free(&credssp->negoToken);
/* NTLMSSP AUTHENTICATE MESSAGE */
s->p = s->end = s->data = negoTokenBuffer;
ntlmssp_send(ntlmssp, s);
/* The last NTLMSSP message is sent with the encrypted public key */
credssp->negoToken.data = s->data;
credssp->negoToken.length = s->end - s->data;
credssp_encrypt_public_key(credssp, &credssp->pubKeyAuth);
credssp_send(credssp, &credssp->negoToken, &credssp->pubKeyAuth, NULL);
/* Encrypted Public Key +1 */
if (credssp_recv(credssp, &credssp->negoToken, &credssp->pubKeyAuth, NULL) < 0)
return -1;
if (credssp_verify_public_key(credssp, &credssp->pubKeyAuth) == 0)
{
/* Failed to verify server public key echo */
return 0; /* DO NOT SEND CREDENTIALS! */
}
datablob_free(&credssp->negoToken);
datablob_free(&credssp->pubKeyAuth);
/* Send encrypted credentials */
credssp_encode_ts_credentials(credssp);
credssp_encrypt_ts_credentials(credssp, &credssp->authInfo);
credssp_send(credssp, NULL, NULL, &credssp->authInfo);
xfree(s);
return 1;
}
/**
* Encrypt TLS public key using CredSSP.
* @param credssp
* @param s
*/
void credssp_encrypt_public_key(rdpCredssp *credssp, DATABLOB *d)
{
uint8 *p;
uint8 signature[16];
DATABLOB encrypted_public_key;
NTLMSSP *ntlmssp = credssp->ntlmssp;
datablob_alloc(d, credssp->public_key.length + 16);
ntlmssp_encrypt_message(ntlmssp, &credssp->public_key, &encrypted_public_key, signature);
#ifdef WITH_DEBUG_NLA
printf("Public Key (length = %d)\n", credssp->public_key.length);
hexdump(credssp->public_key.data, credssp->public_key.length);
printf("\n");
printf("Encrypted Public Key (length = %d)\n", encrypted_public_key.length);
hexdump(encrypted_public_key.data, encrypted_public_key.length);
printf("\n");
printf("Signature\n");
hexdump(signature, 16);
printf("\n");
#endif
p = (uint8*) d->data;
memcpy(p, signature, 16); /* Message Signature */
memcpy(&p[16], encrypted_public_key.data, encrypted_public_key.length); /* Encrypted Public Key */
datablob_free(&encrypted_public_key);
}
/**
* Verify TLS public key using CredSSP.
* @param credssp
* @param s
* @return 1 if verification is successful, 0 otherwise
*/
int credssp_verify_public_key(rdpCredssp *credssp, DATABLOB *d)
{
uint8 *p1, *p2;
uint8 *signature;
DATABLOB public_key;
DATABLOB encrypted_public_key;
signature = d->data;
encrypted_public_key.data = (void*) (signature + 16);
encrypted_public_key.length = d->length - 16;
ntlmssp_decrypt_message(credssp->ntlmssp, &encrypted_public_key, &public_key, signature);
p1 = (uint8*) credssp->public_key.data;
p2 = (uint8*) public_key.data;
p2[0]--;
if (memcmp(p1, p2, public_key.length) != 0)
{
printf("Could not verify server's public key echo\n");
return 0;
}
p2[0]++;
datablob_free(&public_key);
return 1;
}
/**
* Encrypt and sign TSCredentials structure.
* @param credssp
* @param s
*/
void credssp_encrypt_ts_credentials(rdpCredssp *credssp, DATABLOB *d)
{
uint8 *p;
uint8 signature[16];
DATABLOB encrypted_ts_credentials;
NTLMSSP *ntlmssp = credssp->ntlmssp;
datablob_alloc(d, credssp->ts_credentials.length + 16);
ntlmssp_encrypt_message(ntlmssp, &credssp->ts_credentials, &encrypted_ts_credentials, signature);
#ifdef WITH_DEBUG_NLA
printf("TSCredentials (length = %d)\n", credssp->ts_credentials.length);
hexdump(credssp->ts_credentials.data, credssp->ts_credentials.length);
printf("\n");
printf("Encrypted TSCredentials (length = %d)\n", encrypted_ts_credentials.length);
hexdump(encrypted_ts_credentials.data, encrypted_ts_credentials.length);
printf("\n");
printf("Signature\n");
hexdump(signature, 16);
printf("\n");
#endif
p = (uint8*) d->data;
memcpy(p, signature, 16); /* Message Signature */
memcpy(&p[16], encrypted_ts_credentials.data, encrypted_ts_credentials.length); /* Encrypted TSCredentials */
datablob_free(&encrypted_ts_credentials);
}
/**
* Encode TSCredentials structure.
* @param credssp
*/
void credssp_encode_ts_credentials(rdpCredssp *credssp)
{
asn_enc_rval_t enc_rval;
TSCredentials_t *ts_credentials;
TSPasswordCreds_t *ts_password_creds;
DATABLOB ts_password_creds_buffer = { 0 };
ts_credentials = calloc(1, sizeof(TSCredentials_t));
ts_credentials->credType = 1; /* TSPasswordCreds */
ts_password_creds = calloc(1, sizeof(TSPasswordCreds_t));
/* Domain */
ts_password_creds->domainName.buf = credssp->ntlmssp->domain.data;
ts_password_creds->domainName.size = credssp->ntlmssp->domain.length;
/* Username */
ts_password_creds->userName.buf = credssp->ntlmssp->username.data;
ts_password_creds->userName.size = credssp->ntlmssp->username.length;
/* Password */
ts_password_creds->password.buf = credssp->ntlmssp->password.data;
ts_password_creds->password.size = credssp->ntlmssp->password.length;
/* get size ASN.1 encoded TSPasswordCreds */
enc_rval = der_encode(&asn_DEF_TSPasswordCreds, ts_password_creds, asn1_write, 0);
if (enc_rval.encoded != -1)
{
datablob_alloc(&ts_password_creds_buffer, enc_rval.encoded);
enc_rval = der_encode_to_buffer(&asn_DEF_TSPasswordCreds, ts_password_creds,
ts_password_creds_buffer.data, ts_password_creds_buffer.length);
}
ts_credentials->credentials.buf = ts_password_creds_buffer.data;
ts_credentials->credentials.size = ts_password_creds_buffer.length;
/* get size ASN.1 encoded TSCredentials */
enc_rval = der_encode(&asn_DEF_TSCredentials, ts_credentials, asn1_write, 0);
if (enc_rval.encoded != -1)
{
datablob_alloc(&credssp->ts_credentials, enc_rval.encoded);
enc_rval = der_encode_to_buffer(&asn_DEF_TSCredentials, ts_credentials,
credssp->ts_credentials.data, credssp->ts_credentials.length);
}
datablob_free(&ts_password_creds_buffer);
free(ts_credentials);
free(ts_password_creds);
}
/**
* Send CredSSP message.
* @param credssp
* @param negoToken
* @param pubKeyAuth
* @param authInfo
*/
void credssp_send(rdpCredssp *credssp, DATABLOB *negoToken, DATABLOB *pubKeyAuth, DATABLOB *authInfo)
{
TSRequest_t *ts_request;
OCTET_STRING_t *nego_token;
asn_enc_rval_t enc_rval;
char* buffer;
size_t size;
ts_request = calloc(1, sizeof(TSRequest_t));
ts_request->version = 2;
if (negoToken != NULL)
{
ts_request->negoTokens = calloc(1, sizeof(NegoData_t));
nego_token = calloc(1, sizeof(OCTET_STRING_t));
nego_token->size = negoToken->length;
nego_token->buf = malloc(nego_token->size);
memcpy(nego_token->buf, negoToken->data, nego_token->size);
ASN_SEQUENCE_ADD(ts_request->negoTokens, nego_token);
}
if (pubKeyAuth != NULL)
{
ts_request->pubKeyAuth = calloc(1, sizeof(OCTET_STRING_t));
ts_request->pubKeyAuth->buf = pubKeyAuth->data;
ts_request->pubKeyAuth->size = pubKeyAuth->length;
}
if (authInfo != NULL)
{
ts_request->authInfo = calloc(1, sizeof(OCTET_STRING_t));
ts_request->authInfo->buf = authInfo->data;
ts_request->authInfo->size = authInfo->length;
}
/* get size of the encoded ASN.1 payload */
enc_rval = der_encode(&asn_DEF_TSRequest, ts_request, asn1_write, 0);
if (enc_rval.encoded != -1)
{
size = enc_rval.encoded;
buffer = xmalloc(size);
enc_rval = der_encode_to_buffer(&asn_DEF_TSRequest, ts_request, buffer, size);
if (enc_rval.encoded != -1)
{
tls_write(credssp->net->tls, buffer, size);
}
asn_DEF_TSRequest.free_struct(&asn_DEF_TSRequest, ts_request, 0);
xfree(buffer);
}
}
/**
* Receive CredSSP message.
* @param credssp
* @param negoToken
* @param pubKeyAuth
* @param authInfo
* @return
*/
int credssp_recv(rdpCredssp *credssp, DATABLOB *negoToken, DATABLOB *pubKeyAuth, DATABLOB *authInfo)
{
int bytes_read;
int size = 2048;
char *recv_buffer;
asn_dec_rval_t dec_rval;
TSRequest_t *ts_request = 0;
recv_buffer = xmalloc(size);
bytes_read = tls_read(credssp->net->tls, recv_buffer, size);
if (bytes_read < 0)
return -1;
dec_rval = ber_decode(0, &asn_DEF_TSRequest, (void **)&ts_request, recv_buffer, bytes_read);
if(dec_rval.code == RC_OK)
{
if (ts_request->negoTokens != NULL)
{
if (ts_request->negoTokens->list.count > 0)
{
datablob_alloc(negoToken, ts_request->negoTokens->list.array[0]->negoToken.size);
memcpy(negoToken->data, ts_request->negoTokens->list.array[0]->negoToken.buf, negoToken->length);
}
}
if (ts_request->pubKeyAuth != NULL)
{
datablob_alloc(pubKeyAuth, ts_request->pubKeyAuth->size);
memcpy(pubKeyAuth->data, ts_request->pubKeyAuth->buf, pubKeyAuth->length);
}
asn_DEF_TSRequest.free_struct(&asn_DEF_TSRequest, ts_request, 0);
}
else
{
printf("Failed to decode TSRequest\n");
asn_DEF_TSRequest.free_struct(&asn_DEF_TSRequest, ts_request, 0);
}
xfree(recv_buffer);
return 0;
}
/**
* Encrypt the given plain text using RC4 and the given key.
* @param key RC4 key
* @param length text length
* @param plaintext plain text
* @param ciphertext cipher text
*/
void credssp_rc4k(uint8* key, int length, uint8* plaintext, uint8* ciphertext)
{
CryptoRc4 rc4;
/* Initialize RC4 cipher with key */
rc4 = crypto_rc4_init((void*) key, 16);
/* Encrypt plaintext with key */
crypto_rc4(rc4, length, (void*) plaintext, (void*) ciphertext);
/* Free RC4 Cipher */
crypto_rc4_free(rc4);
}
/**
* Get current time, in tenths of microseconds since midnight of January 1, 1601.
* @param[out] timestamp 64-bit little-endian timestamp
*/
void credssp_current_time(uint8* timestamp)
{
uint64 time64;
/* Timestamp (8 bytes), represented as the number of tenths of microseconds since midnight of January 1, 1601 */
time64 = time(NULL) + 11644473600LL; /* Seconds since January 1, 1601 */
time64 *= 10000000; /* Convert timestamp to tenths of a microsecond */
memcpy(timestamp, &time64, 8); /* Copy into timestamp in little-endian */
}
/**
* Create new CredSSP state machine.
* @param sec
* @return new CredSSP state machine.
*/
rdpCredssp *
credssp_new(struct rdp_network * net)
{
rdpCredssp * self;
self = (rdpCredssp *) xmalloc(sizeof(rdpCredssp));
if (self != NULL)
{
memset(self, 0, sizeof(rdpCredssp));
self->net = net;
self->send_seq_num = 0;
self->ntlmssp = ntlmssp_new();
}
return self;
}
/**
* Free CredSSP state machine.
* @param credssp
*/
void
credssp_free(rdpCredssp * credssp)
{
if (credssp != NULL)
{
datablob_free(&credssp->public_key);
datablob_free(&credssp->ts_credentials);
ntlmssp_free(credssp->ntlmssp);
xfree(credssp);
}
}

56
libfreerdp-core/credssp.h Normal file
View File

@ -0,0 +1,56 @@
/**
* FreeRDP: A Remote Desktop Protocol Client
* Credential Security Support Provider (CredSSP)
*
* Copyright 2010 Marc-Andre Moreau <marcandre.moreau@gmail.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __CREDSSP_H
#define __CREDSSP_H
#include "network.h"
#include "ntlmssp.h"
struct rdp_credssp
{
DATABLOB negoToken;
DATABLOB pubKeyAuth;
DATABLOB authInfo;
int send_seq_num;
DATABLOB public_key;
DATABLOB ts_credentials;
CryptoRc4 rc4_seal_state;
struct _NTLMSSP *ntlmssp;
struct rdp_network * net;
};
typedef struct rdp_credssp rdpCredssp;
int credssp_authenticate(rdpCredssp *credssp);
void credssp_send(rdpCredssp *credssp, DATABLOB *negoToken, DATABLOB *pubKeyAuth, DATABLOB *authInfo);
int credssp_recv(rdpCredssp *credssp, DATABLOB *negoToken, DATABLOB *pubKeyAuth, DATABLOB *authInfo);
void credssp_encrypt_public_key(rdpCredssp *credssp, DATABLOB *d);
void credssp_encrypt_ts_credentials(rdpCredssp *credssp, DATABLOB *d);
int credssp_verify_public_key(rdpCredssp *credssp, DATABLOB *d);
void credssp_encode_ts_credentials(rdpCredssp *credssp);
void credssp_current_time(uint8* timestamp);
void credssp_rc4k(uint8* key, int length, uint8* plaintext, uint8* ciphertext);
rdpCredssp* credssp_new(struct rdp_network * net);
void credssp_free(rdpCredssp *credssp);
#endif /* __CREDSSP_H */