void license_generate_randoms(rdpLicense* license)
{
#if 0
crypto_nonce(license->client_random, CLIENT_RANDOM_LENGTH); /* ClientRandom */
crypto_nonce(license->premaster_secret, PREMASTER_SECRET_LENGTH); /* PremasterSecret */
#else
memset(license->client_random, 0, CLIENT_RANDOM_LENGTH); /* ClientRandom */
memset(license->premaster_secret, 0, PREMASTER_SECRET_LENGTH); /* PremasterSecret */
#endif
}
void license_generate_randoms(rdpLicense* license)
{
ZeroMemory(license->ClientRandom, CLIENT_RANDOM_LENGTH); /* ClientRandom */
ZeroMemory(license->PremasterSecret, PREMASTER_SECRET_LENGTH); /* PremasterSecret */
#ifndef LICENSE_NULL_CLIENT_RANDOM
crypto_nonce(license->ClientRandom, CLIENT_RANDOM_LENGTH); /* ClientRandom */
#endif
#ifndef LICENSE_NULL_PREMASTER_SECRET
crypto_nonce(license->PremasterSecret, PREMASTER_SECRET_LENGTH); /* PremasterSecret */
#endif
}
void krb_reqbody_init(KRB_CONTEXT* krb_ctx, KDCReqBody* req_body, uint8 reqtype)
{
time_t t;
req_body->cname = xstrdup(krb_ctx->cname);
req_body->realm = xstrdup(krb_ctx->realm);
if (reqtype == KRB_TAG_ASREQ)
{
req_body->kdc_options = 0x40000000 | 0x00800000 | 0x00010000 | 0x00000010; /* forwardable , renewable, canonicalize, renewable OK */
req_body->sname = xzalloc((strlen(req_body->realm) + 8) * sizeof(char));
strcpy(req_body->sname, KRB_SERVER);
strcat(req_body->sname, req_body->realm);
}
else if (reqtype == KRB_TAG_TGSREQ)
{
req_body->kdc_options = 0x40000000 | 0x00800000 | 0x00010000; /* forwardable , renewable, canonicalize */
req_body->sname = xzalloc((strlen(krb_ctx->settings->hostname) + 10) * sizeof(char));
strcpy(req_body->sname, APP_SERVER);
strcat(req_body->sname, krb_ctx->settings->hostname);
}
t = time(NULL);
t += krb_ctx->clockskew; /* fix clockskew */
req_body->from = get_utc_time((time_t)(t));
req_body->till = get_utc_time((time_t)(t + 473040000));
req_body->rtime = get_utc_time((time_t)(t + 473040000));
crypto_nonce((uint8*) &(req_body->nonce), 4);
}
rdpBlob* crypto_kdcmsg_encrypt_rc4(rdpBlob* msg, uint8* key, uint32 msgtype)
{
rdpBlob* encmsg;
uint8* K1;
uint8* K3;
uint32 len;
krbEdata* edata;
CryptoRc4 rc4;
K1 = xzalloc(16);
K3 = xzalloc(16);
len = ((msg->length > 16) ? msg->length : 16);
len += sizeof(krbEdata);
edata = xzalloc(len);
encmsg = xnew(rdpBlob);
freerdp_blob_alloc(encmsg, len);
HMAC(EVP_md5(), (void*) key, 16, (uint8*)&msgtype, 4, (void*) K1, NULL);
crypto_nonce((uint8*)(edata->Confounder), 8);
memcpy(&(edata->data[0]), msg->data, msg->length);
HMAC(EVP_md5(), (void*) K1, 16, (uint8*)edata->Confounder, len - 16, (void*)&(edata->Checksum), NULL);
HMAC(EVP_md5(), (void*) K1, 16, (uint8*)&(edata->Checksum), 16, (void*)K3, NULL);
memcpy(encmsg->data, &(edata->Checksum), 16);
rc4 = crypto_rc4_init(K3, 16);
crypto_rc4(rc4, len - 16, (uint8*) edata->Confounder, (uint8*)(((uint8*) encmsg->data) + 16));
crypto_rc4_free(rc4);
xfree(K1);
xfree(K3);
xfree(edata);
return encmsg;
}
static BOOL rdp_client_establish_keys(rdpRdp* rdp)
{
BYTE* mod;
BYTE* exp;
wStream* s;
UINT32 length;
UINT32 key_len;
BYTE crypt_client_random[256 + 8];
if (!rdp->settings->DisableEncryption)
{
/* no RDP encryption */
return TRUE;
}
/* encrypt client random */
if (rdp->settings->ClientRandom)
free(rdp->settings->ClientRandom);
rdp->settings->ClientRandom = malloc(CLIENT_RANDOM_LENGTH);
if (!rdp->settings->ClientRandom)
return FALSE;
ZeroMemory(crypt_client_random, sizeof(crypt_client_random));
crypto_nonce(rdp->settings->ClientRandom, CLIENT_RANDOM_LENGTH);
key_len = rdp->settings->RdpServerCertificate->cert_info.ModulusLength;
mod = rdp->settings->RdpServerCertificate->cert_info.Modulus;
exp = rdp->settings->RdpServerCertificate->cert_info.exponent;
crypto_rsa_public_encrypt(rdp->settings->ClientRandom, CLIENT_RANDOM_LENGTH, key_len, mod, exp, crypt_client_random);
/* send crypt client random to server */
length = RDP_PACKET_HEADER_MAX_LENGTH + RDP_SECURITY_HEADER_LENGTH + 4 + key_len + 8;
s = Stream_New(NULL, length);
rdp_write_header(rdp, s, length, MCS_GLOBAL_CHANNEL_ID);
rdp_write_security_header(s, SEC_EXCHANGE_PKT);
length = key_len + 8;
Stream_Write_UINT32(s, length);
Stream_Write(s, crypt_client_random, length);
Stream_SealLength(s);
if (transport_write(rdp->mcs->transport, s) < 0)
{
return FALSE;
}
Stream_Free(s, TRUE);
/* now calculate encrypt / decrypt and update keys */
if (!security_establish_keys(rdp->settings->ClientRandom, rdp))
{
return FALSE;
}
rdp->do_crypt = TRUE;
if (rdp->settings->SaltedChecksum)
rdp->do_secure_checksum = TRUE;
if (rdp->settings->EncryptionMethods == ENCRYPTION_METHOD_FIPS)
{
rdp->fips_encrypt = crypto_des3_encrypt_init(rdp->fips_encrypt_key, fips_ivec);
rdp->fips_decrypt = crypto_des3_decrypt_init(rdp->fips_decrypt_key, fips_ivec);
rdp->fips_hmac = crypto_hmac_new();
return TRUE;
}
rdp->rc4_decrypt_key = crypto_rc4_init(rdp->decrypt_key, rdp->rc4_key_len);
rdp->rc4_encrypt_key = crypto_rc4_init(rdp->encrypt_key, rdp->rc4_key_len);
return TRUE;
}
static boolean rdp_client_establish_keys(rdpRdp* rdp)
{
uint8 client_random[CLIENT_RANDOM_LENGTH];
uint8 crypt_client_random[256 + 8];
uint32 key_len;
uint8* mod;
uint8* exp;
uint32 length;
STREAM* s;
if (rdp->settings->encryption == false)
{
/* no RDP encryption */
return true;
}
/* encrypt client random */
memset(crypt_client_random, 0, sizeof(crypt_client_random));
crypto_nonce(client_random, sizeof(client_random));
key_len = rdp->settings->server_cert->cert_info.modulus.length;
mod = rdp->settings->server_cert->cert_info.modulus.data;
exp = rdp->settings->server_cert->cert_info.exponent;
crypto_rsa_public_encrypt(client_random, sizeof(client_random), key_len, mod, exp, crypt_client_random);
/* send crypt client random to server */
length = RDP_PACKET_HEADER_MAX_LENGTH + RDP_SECURITY_HEADER_LENGTH + 4 + key_len + 8;
s = transport_send_stream_init(rdp->mcs->transport, length);
rdp_write_header(rdp, s, length, MCS_GLOBAL_CHANNEL_ID);
rdp_write_security_header(s, SEC_EXCHANGE_PKT);
length = key_len + 8;
stream_write_uint32(s, length);
stream_write(s, crypt_client_random, length);
if (transport_write(rdp->mcs->transport, s) < 0)
{
return false;
}
/* now calculate encrypt / decrypt and update keys */
if (!security_establish_keys(client_random, rdp))
{
return false;
}
rdp->do_crypt = true;
if (rdp->settings->salted_checksum)
rdp->do_secure_checksum = true;
if (rdp->settings->encryption_method == ENCRYPTION_METHOD_FIPS)
{
uint8 fips_ivec[8] = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
rdp->fips_encrypt = crypto_des3_encrypt_init(rdp->fips_encrypt_key, fips_ivec);
rdp->fips_decrypt = crypto_des3_decrypt_init(rdp->fips_decrypt_key, fips_ivec);
rdp->fips_hmac = crypto_hmac_new();
return true;
}
rdp->rc4_decrypt_key = crypto_rc4_init(rdp->decrypt_key, rdp->rc4_key_len);
rdp->rc4_encrypt_key = crypto_rc4_init(rdp->encrypt_key, rdp->rc4_key_len);
return true;
}
static boolean rdp_establish_keys(rdpRdp* rdp)
{
uint8 client_random[32];
uint8 crypt_client_random[256 + 8];
uint32 key_len;
uint8* mod;
uint8* exp;
uint32 length;
STREAM* s;
if (rdp->settings->encryption == False)
{
/* no RDP encryption */
return True;
}
/* encrypt client random */
memset(crypt_client_random, 0, sizeof(crypt_client_random));
memset(client_random, 0x5e, 32);
crypto_nonce(client_random, 32);
key_len = rdp->settings->server_cert->cert_info.modulus.length;
mod = rdp->settings->server_cert->cert_info.modulus.data;
exp = rdp->settings->server_cert->cert_info.exponent;
crypto_rsa_encrypt(client_random, 32, key_len, mod, exp, crypt_client_random);
/* send crypt client random to server */
length = 7 + 8 + 4 + 4 + key_len + 8;
s = transport_send_stream_init(rdp->mcs->transport, length);
tpkt_write_header(s, length);
tpdu_write_header(s, 2, 0xf0);
per_write_choice(s, DomainMCSPDU_SendDataRequest << 2);
per_write_integer16(s, rdp->mcs->user_id, MCS_BASE_CHANNEL_ID);
per_write_integer16(s, MCS_GLOBAL_CHANNEL_ID, 0);
stream_write_uint8(s, 0x70);
length = (4 + 4 + key_len + 8) | 0x8000;
stream_write_uint16_be(s, length);
stream_write_uint32(s, 1); /* SEC_CLIENT_RANDOM */
length = key_len + 8;
stream_write_uint32(s, length);
memcpy(s->p, crypt_client_random, length);
stream_seek(s, length);
if (transport_write(rdp->mcs->transport, s) < 0)
{
return False;
}
/* now calculate encrypt / decrypt and update keys */
if (!security_establish_keys(client_random, rdp))
{
return False;
}
rdp->do_crypt = True;
if (rdp->settings->encryption_method == ENCRYPTION_METHOD_FIPS)
{
uint8 fips_ivec[8] = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
rdp->fips_encrypt = crypto_des3_encrypt_init(rdp->fips_encrypt_key, fips_ivec);
rdp->fips_decrypt = crypto_des3_decrypt_init(rdp->fips_decrypt_key, fips_ivec);
rdp->fips_hmac = crypto_hmac_new();
return True;
}
rdp->rc4_decrypt_key = crypto_rc4_init(rdp->decrypt_key, rdp->rc4_key_len);
rdp->rc4_encrypt_key = crypto_rc4_init(rdp->encrypt_key, rdp->rc4_key_len);
return True;
}
void krb_tgsreq_send(KRB_CONTEXT* krb_ctx, uint8 errcode)
{
KrbTGSREQ* krb_tgsreq;
KrbAPREQ* krb_apreq;
PAData** pa_data;
Authenticator* krb_auth;
STREAM* s;
STREAM* sapreq;
rdpBlob msg;
uint32 curlen, totlen, tmp;
uint8 *bm;
bm = NULL;
totlen = tmp = 0;
krb_tgsreq = krb_tgsreq_new(krb_ctx, errcode);
krb_auth = xnew(Authenticator);
pa_data = krb_tgsreq->padata;
s = stream_new(4096);
sapreq = stream_new(2048);
//Begin write asn1 data reversely into stream
stream_seek(s, 4095);
stream_seek(sapreq, 2047);
/* KDC-REQ-BODY (TAG 4) */
totlen += krb_encode_req_body(s, &(krb_tgsreq->req_body), krb_tgsreq->type);
stream_get_mark(s, bm);
tmp = totlen;
totlen += krb_encode_contextual_tag(s, 4, totlen);
msg.data = bm;
msg.length = tmp;
/* Authenticator */
krb_auth->avno = KRB_VERSION;
krb_auth->cname = krb_ctx->cname;
krb_auth->crealm = krb_ctx->realm;
krb_auth->cksumtype = get_cksum_type(krb_ctx->enctype);
krb_auth->cksum = crypto_kdcmsg_cksum(&msg, krb_ctx->askey, 6); //RFC4757 section 3 for msgtype (T=6)
krb_auth->ctime = krb_tgsreq->req_body.from;
krb_auth->cusec = 0;
crypto_nonce((uint8*)&(krb_auth->seqno), 4);
/* PA-TGS-REQ */
krb_apreq = krb_apreq_new(krb_ctx, &(krb_ctx->asticket), krb_auth);
curlen = krb_encode_apreq(sapreq, krb_apreq);
msg.data = sapreq->p;
msg.length = curlen;
(*pa_data)->type = 1;
(*pa_data)->value = msg;
/* PA-DATA (TAG 3) */
curlen = krb_encode_padata(s, pa_data);
totlen += curlen + krb_encode_contextual_tag(s, 3, curlen);
/* MSGTYPE (TAG 2) */
totlen += krb_encode_uint8(s, 2, krb_tgsreq->type);
/* VERSION NO (TAG 1) */
totlen += krb_encode_uint8(s, 1, krb_tgsreq->pvno);
totlen += krb_encode_sequence_tag(s, totlen);
totlen += krb_encode_application_tag(s, krb_tgsreq->type, totlen);
totlen += krb_encode_recordmark(s, totlen);
/* READY SEND */
krb_tcp_send(krb_ctx, s->p, totlen);
/* save stuff */
krb_ctx->nonce = krb_tgsreq->req_body.nonce;
xfree(krb_ctx->sname);
krb_ctx->sname = xstrdup(krb_tgsreq->req_body.sname);
krb_ctx->ctime = get_local_time(krb_tgsreq->req_body.from);
krb_ctx->state = KRB_TGSREQ_OK;
/* clean up */
freerdp_blob_free(krb_auth->cksum);
xfree(krb_auth->cksum);
xfree(krb_auth);
krb_free_tgsreq(krb_tgsreq);
xfree(krb_tgsreq);
stream_free(sapreq);
stream_free(s);
}
void gcc_write_server_security_data(wStream* s, rdpMcs* mcs)
{
CryptoMd5 md5;
BYTE* sigData;
int expLen, keyLen, sigDataLen;
BYTE encryptedSignature[TSSK_KEY_LENGTH];
BYTE signature[sizeof(initial_signature)];
UINT32 headerLen, serverRandomLen, serverCertLen, wPublicKeyBlobLen;
rdpSettings* settings = mcs->settings;
/**
* Re: settings->EncryptionLevel:
* This is configured/set by the server implementation and serves the same
* purpose as the "Encryption Level" setting in the RDP-Tcp configuration
* dialog of Microsoft's Remote Desktop Session Host Configuration.
* Re: settings->EncryptionMethods:
* at this point this setting contains the client's supported encryption
* methods we've received in gcc_read_client_security_data()
*/
if (!settings->UseRdpSecurityLayer)
{
/* TLS/NLA is used: disable rdp style encryption */
settings->EncryptionLevel = ENCRYPTION_LEVEL_NONE;
}
/* verify server encryption level value */
switch (settings->EncryptionLevel)
{
case ENCRYPTION_LEVEL_NONE:
WLog_INFO(TAG, "Active rdp encryption level: NONE");
break;
case ENCRYPTION_LEVEL_FIPS:
WLog_INFO(TAG, "Active rdp encryption level: FIPS Compliant");
break;
case ENCRYPTION_LEVEL_HIGH:
WLog_INFO(TAG, "Active rdp encryption level: HIGH");
break;
case ENCRYPTION_LEVEL_LOW:
WLog_INFO(TAG, "Active rdp encryption level: LOW");
break;
case ENCRYPTION_LEVEL_CLIENT_COMPATIBLE:
WLog_INFO(TAG, "Active rdp encryption level: CLIENT-COMPATIBLE");
break;
default:
WLog_ERR(TAG, "Invalid server encryption level 0x%08X", settings->EncryptionLevel);
WLog_ERR(TAG, "Switching to encryption level CLIENT-COMPATIBLE");
settings->EncryptionLevel = ENCRYPTION_LEVEL_CLIENT_COMPATIBLE;
}
/* choose rdp encryption method based on server level and client methods */
switch (settings->EncryptionLevel)
{
case ENCRYPTION_LEVEL_NONE:
/* The only valid method is NONE in this case */
settings->EncryptionMethods = ENCRYPTION_METHOD_NONE;
break;
case ENCRYPTION_LEVEL_FIPS:
/* The only valid method is FIPS in this case */
if (!(settings->EncryptionMethods & ENCRYPTION_METHOD_FIPS))
{
WLog_WARN(TAG, "client does not support FIPS as required by server configuration");
}
settings->EncryptionMethods = ENCRYPTION_METHOD_FIPS;
break;
case ENCRYPTION_LEVEL_HIGH:
/* Maximum key strength supported by the server must be used (128 bit)*/
if (!(settings->EncryptionMethods & ENCRYPTION_METHOD_128BIT))
{
WLog_WARN(TAG, "client does not support 128 bit encryption method as required by server configuration");
}
settings->EncryptionMethods = ENCRYPTION_METHOD_128BIT;
break;
case ENCRYPTION_LEVEL_LOW:
case ENCRYPTION_LEVEL_CLIENT_COMPATIBLE:
/* Maximum key strength supported by the client must be used */
if (settings->EncryptionMethods & ENCRYPTION_METHOD_128BIT)
settings->EncryptionMethods = ENCRYPTION_METHOD_128BIT;
else if (settings->EncryptionMethods & ENCRYPTION_METHOD_56BIT)
settings->EncryptionMethods = ENCRYPTION_METHOD_56BIT;
else if (settings->EncryptionMethods & ENCRYPTION_METHOD_40BIT)
settings->EncryptionMethods = ENCRYPTION_METHOD_40BIT;
else if (settings->EncryptionMethods & ENCRYPTION_METHOD_FIPS)
settings->EncryptionMethods = ENCRYPTION_METHOD_FIPS;
else
{
WLog_WARN(TAG, "client has not announced any supported encryption methods");
settings->EncryptionMethods = ENCRYPTION_METHOD_128BIT;
}
break;
default:
WLog_ERR(TAG, "internal error: unknown encryption level");
}
/* log selected encryption method */
switch (settings->EncryptionMethods)
{
case ENCRYPTION_METHOD_NONE:
WLog_INFO(TAG, "Selected rdp encryption method: NONE");
break;
case ENCRYPTION_METHOD_40BIT:
WLog_INFO(TAG, "Selected rdp encryption method: 40BIT");
break;
case ENCRYPTION_METHOD_56BIT:
WLog_INFO(TAG, "Selected rdp encryption method: 56BIT");
break;
case ENCRYPTION_METHOD_128BIT:
WLog_INFO(TAG, "Selected rdp encryption method: 128BIT");
break;
case ENCRYPTION_METHOD_FIPS:
WLog_INFO(TAG, "Selected rdp encryption method: FIPS");
break;
default:
WLog_ERR(TAG, "internal error: unknown encryption method");
}
headerLen = 12;
keyLen = 0;
wPublicKeyBlobLen = 0;
serverRandomLen = 0;
serverCertLen = 0;
if (settings->EncryptionMethods != ENCRYPTION_METHOD_NONE)
{
serverRandomLen = 32;
keyLen = settings->RdpServerRsaKey->ModulusLength;
expLen = sizeof(settings->RdpServerRsaKey->exponent);
wPublicKeyBlobLen = 4; /* magic (RSA1) */
wPublicKeyBlobLen += 4; /* keylen */
wPublicKeyBlobLen += 4; /* bitlen */
wPublicKeyBlobLen += 4; /* datalen */
wPublicKeyBlobLen += expLen;
wPublicKeyBlobLen += keyLen;
wPublicKeyBlobLen += 8; /* 8 bytes of zero padding */
serverCertLen = 4; /* dwVersion */
serverCertLen += 4; /* dwSigAlgId */
serverCertLen += 4; /* dwKeyAlgId */
serverCertLen += 2; /* wPublicKeyBlobType */
serverCertLen += 2; /* wPublicKeyBlobLen */
serverCertLen += wPublicKeyBlobLen;
serverCertLen += 2; /* wSignatureBlobType */
serverCertLen += 2; /* wSignatureBlobLen */
serverCertLen += sizeof(encryptedSignature); /* SignatureBlob */
serverCertLen += 8; /* 8 bytes of zero padding */
headerLen += sizeof(serverRandomLen);
headerLen += sizeof(serverCertLen);
headerLen += serverRandomLen;
headerLen += serverCertLen;
}
gcc_write_user_data_header(s, SC_SECURITY, headerLen);
Stream_Write_UINT32(s, settings->EncryptionMethods); /* encryptionMethod */
Stream_Write_UINT32(s, settings->EncryptionLevel); /* encryptionLevel */
if (settings->EncryptionMethods == ENCRYPTION_METHOD_NONE)
{
return;
}
Stream_Write_UINT32(s, serverRandomLen); /* serverRandomLen */
Stream_Write_UINT32(s, serverCertLen); /* serverCertLen */
settings->ServerRandomLength = serverRandomLen;
settings->ServerRandom = (BYTE*) malloc(serverRandomLen);
crypto_nonce(settings->ServerRandom, serverRandomLen);
Stream_Write(s, settings->ServerRandom, serverRandomLen);
sigData = Stream_Pointer(s);
Stream_Write_UINT32(s, CERT_CHAIN_VERSION_1); /* dwVersion (4 bytes) */
Stream_Write_UINT32(s, SIGNATURE_ALG_RSA); /* dwSigAlgId */
Stream_Write_UINT32(s, KEY_EXCHANGE_ALG_RSA); /* dwKeyAlgId */
Stream_Write_UINT16(s, BB_RSA_KEY_BLOB); /* wPublicKeyBlobType */
Stream_Write_UINT16(s, wPublicKeyBlobLen); /* wPublicKeyBlobLen */
Stream_Write(s, "RSA1", 4); /* magic */
Stream_Write_UINT32(s, keyLen + 8); /* keylen */
Stream_Write_UINT32(s, keyLen * 8); /* bitlen */
Stream_Write_UINT32(s, keyLen - 1); /* datalen */
Stream_Write(s, settings->RdpServerRsaKey->exponent, expLen);
Stream_Write(s, settings->RdpServerRsaKey->Modulus, keyLen);
Stream_Zero(s, 8);
sigDataLen = Stream_Pointer(s) - sigData;
Stream_Write_UINT16(s, BB_RSA_SIGNATURE_BLOB); /* wSignatureBlobType */
Stream_Write_UINT16(s, sizeof(encryptedSignature) + 8); /* wSignatureBlobLen */
memcpy(signature, initial_signature, sizeof(initial_signature));
md5 = crypto_md5_init();
if (!md5)
{
WLog_ERR(TAG, "unable to allocate a md5");
return;
}
crypto_md5_update(md5, sigData, sigDataLen);
crypto_md5_final(md5, signature);
crypto_rsa_private_encrypt(signature, sizeof(signature), TSSK_KEY_LENGTH,
tssk_modulus, tssk_privateExponent, encryptedSignature);
Stream_Write(s, encryptedSignature, sizeof(encryptedSignature));
Stream_Zero(s, 8);
}
static BOOL rdp_client_establish_keys(rdpRdp* rdp)
{
BYTE* mod;
BYTE* exp;
wStream* s;
UINT32 length;
UINT32 key_len;
int status = 0;
BOOL ret = FALSE;
rdpSettings* settings;
BYTE* crypt_client_random = NULL;
settings = rdp->settings;
if (!settings->DisableEncryption)
{
/* no RDP encryption */
return TRUE;
}
/* encrypt client random */
if (settings->ClientRandom)
free(settings->ClientRandom);
settings->ClientRandomLength = CLIENT_RANDOM_LENGTH;
settings->ClientRandom = malloc(settings->ClientRandomLength);
if (!settings->ClientRandom)
return FALSE;
crypto_nonce(settings->ClientRandom, settings->ClientRandomLength);
key_len = settings->RdpServerCertificate->cert_info.ModulusLength;
mod = settings->RdpServerCertificate->cert_info.Modulus;
exp = settings->RdpServerCertificate->cert_info.exponent;
/*
* client random must be (bitlen / 8) + 8 - see [MS-RDPBCGR] 5.3.4.1
* for details
*/
crypt_client_random = calloc(1, key_len + 8);
if (!crypt_client_random)
return FALSE;
crypto_rsa_public_encrypt(settings->ClientRandom, settings->ClientRandomLength, key_len, mod, exp, crypt_client_random);
/* send crypt client random to server */
length = RDP_PACKET_HEADER_MAX_LENGTH + RDP_SECURITY_HEADER_LENGTH + 4 + key_len + 8;
s = Stream_New(NULL, length);
rdp_write_header(rdp, s, length, MCS_GLOBAL_CHANNEL_ID);
rdp_write_security_header(s, SEC_EXCHANGE_PKT | SEC_LICENSE_ENCRYPT_SC);
length = key_len + 8;
Stream_Write_UINT32(s, length);
Stream_Write(s, crypt_client_random, length);
Stream_SealLength(s);
status = transport_write(rdp->mcs->transport, s);
Stream_Free(s, TRUE);
if (status < 0)
goto end;
rdp->do_crypt_license = TRUE;
/* now calculate encrypt / decrypt and update keys */
if (!security_establish_keys(settings->ClientRandom, rdp))
goto end;
rdp->do_crypt = TRUE;
if (settings->SaltedChecksum)
rdp->do_secure_checksum = TRUE;
if (settings->EncryptionMethods == ENCRYPTION_METHOD_FIPS)
{
rdp->fips_encrypt = crypto_des3_encrypt_init(rdp->fips_encrypt_key, fips_ivec);
if (!rdp->fips_encrypt)
{
WLog_ERR(TAG, "unable to allocate des3 encrypt key");
goto end;
}
rdp->fips_decrypt = crypto_des3_decrypt_init(rdp->fips_decrypt_key, fips_ivec);
if (!rdp->fips_decrypt)
{
WLog_ERR(TAG, "unable to allocate des3 decrypt key");
goto end;
}
rdp->fips_hmac = crypto_hmac_new();
if (!rdp->fips_hmac)
{
WLog_ERR(TAG, "unable to allocate fips hmac");
goto end;
}
ret = TRUE;
goto end;
}
rdp->rc4_decrypt_key = crypto_rc4_init(rdp->decrypt_key, rdp->rc4_key_len);
if (!rdp->rc4_decrypt_key)
{
WLog_ERR(TAG, "unable to allocate rc4 decrypt key");
goto end;
}
rdp->rc4_encrypt_key = crypto_rc4_init(rdp->encrypt_key, rdp->rc4_key_len);
if (!rdp->rc4_encrypt_key)
{
WLog_ERR(TAG, "unable to allocate rc4 encrypt key");
goto end;
}
ret = TRUE;
end:
if (crypt_client_random)
free(crypt_client_random);
return ret;
}
void gcc_write_server_security_data(wStream* s, rdpMcs* mcs)
{
CryptoMd5 md5;
BYTE* sigData;
int expLen, keyLen, sigDataLen;
BYTE encryptedSignature[TSSK_KEY_LENGTH];
BYTE signature[sizeof(initial_signature)];
UINT32 headerLen, serverRandomLen, serverCertLen, wPublicKeyBlobLen;
rdpSettings* settings = mcs->settings;
if (!settings->DisableEncryption)
{
settings->EncryptionMethods = ENCRYPTION_METHOD_NONE;
settings->EncryptionLevel = ENCRYPTION_LEVEL_NONE;
}
else if ((settings->EncryptionMethods & ENCRYPTION_METHOD_FIPS) != 0)
{
settings->EncryptionMethods = ENCRYPTION_METHOD_FIPS;
}
else if ((settings->EncryptionMethods & ENCRYPTION_METHOD_128BIT) != 0)
{
settings->EncryptionMethods = ENCRYPTION_METHOD_128BIT;
}
else if ((settings->EncryptionMethods & ENCRYPTION_METHOD_40BIT) != 0)
{
settings->EncryptionMethods = ENCRYPTION_METHOD_40BIT;
}
if (settings->EncryptionMethods != ENCRYPTION_METHOD_NONE)
settings->EncryptionLevel = ENCRYPTION_LEVEL_CLIENT_COMPATIBLE;
headerLen = 12;
keyLen = 0;
wPublicKeyBlobLen = 0;
serverRandomLen = 0;
serverCertLen = 0;
if (settings->EncryptionMethods != ENCRYPTION_METHOD_NONE ||
settings->EncryptionLevel != ENCRYPTION_LEVEL_NONE)
{
serverRandomLen = 32;
keyLen = settings->RdpServerRsaKey->ModulusLength;
expLen = sizeof(settings->RdpServerRsaKey->exponent);
wPublicKeyBlobLen = 4; /* magic (RSA1) */
wPublicKeyBlobLen += 4; /* keylen */
wPublicKeyBlobLen += 4; /* bitlen */
wPublicKeyBlobLen += 4; /* datalen */
wPublicKeyBlobLen += expLen;
wPublicKeyBlobLen += keyLen;
wPublicKeyBlobLen += 8; /* 8 bytes of zero padding */
serverCertLen = 4; /* dwVersion */
serverCertLen += 4; /* dwSigAlgId */
serverCertLen += 4; /* dwKeyAlgId */
serverCertLen += 2; /* wPublicKeyBlobType */
serverCertLen += 2; /* wPublicKeyBlobLen */
serverCertLen += wPublicKeyBlobLen;
serverCertLen += 2; /* wSignatureBlobType */
serverCertLen += 2; /* wSignatureBlobLen */
serverCertLen += sizeof(encryptedSignature); /* SignatureBlob */
serverCertLen += 8; /* 8 bytes of zero padding */
headerLen += sizeof(serverRandomLen);
headerLen += sizeof(serverCertLen);
headerLen += serverRandomLen;
headerLen += serverCertLen;
}
gcc_write_user_data_header(s, SC_SECURITY, headerLen);
Stream_Write_UINT32(s, settings->EncryptionMethods); /* encryptionMethod */
Stream_Write_UINT32(s, settings->EncryptionLevel); /* encryptionLevel */
if (settings->EncryptionMethods == ENCRYPTION_METHOD_NONE &&
settings->EncryptionLevel == ENCRYPTION_LEVEL_NONE)
{
return;
}
Stream_Write_UINT32(s, serverRandomLen); /* serverRandomLen */
Stream_Write_UINT32(s, serverCertLen); /* serverCertLen */
settings->ServerRandomLength = serverRandomLen;
settings->ServerRandom = (BYTE*) malloc(serverRandomLen);
crypto_nonce(settings->ServerRandom, serverRandomLen);
Stream_Write(s, settings->ServerRandom, serverRandomLen);
sigData = Stream_Pointer(s);
Stream_Write_UINT32(s, CERT_CHAIN_VERSION_1); /* dwVersion (4 bytes) */
Stream_Write_UINT32(s, SIGNATURE_ALG_RSA); /* dwSigAlgId */
Stream_Write_UINT32(s, KEY_EXCHANGE_ALG_RSA); /* dwKeyAlgId */
Stream_Write_UINT16(s, BB_RSA_KEY_BLOB); /* wPublicKeyBlobType */
Stream_Write_UINT16(s, wPublicKeyBlobLen); /* wPublicKeyBlobLen */
Stream_Write(s, "RSA1", 4); /* magic */
Stream_Write_UINT32(s, keyLen + 8); /* keylen */
Stream_Write_UINT32(s, keyLen * 8); /* bitlen */
Stream_Write_UINT32(s, keyLen - 1); /* datalen */
Stream_Write(s, settings->RdpServerRsaKey->exponent, expLen);
Stream_Write(s, settings->RdpServerRsaKey->Modulus, keyLen);
Stream_Zero(s, 8);
sigDataLen = Stream_Pointer(s) - sigData;
Stream_Write_UINT16(s, BB_RSA_SIGNATURE_BLOB); /* wSignatureBlobType */
Stream_Write_UINT16(s, keyLen + 8); /* wSignatureBlobLen */
memcpy(signature, initial_signature, sizeof(initial_signature));
md5 = crypto_md5_init();
crypto_md5_update(md5, sigData, sigDataLen);
crypto_md5_final(md5, signature);
crypto_rsa_private_encrypt(signature, sizeof(signature), TSSK_KEY_LENGTH,
tssk_modulus, tssk_privateExponent, encryptedSignature);
Stream_Write(s, encryptedSignature, sizeof(encryptedSignature));
Stream_Zero(s, 8);
}
void gcc_write_server_security_data(STREAM* s, rdpSettings* settings)
{
CryptoMd5 md5;
uint8* sigData;
int expLen, keyLen, sigDataLen;
uint8 encryptedSignature[TSSK_KEY_LENGTH];
uint8 signature[sizeof(initial_signature)];
uint32 headerLen, serverRandomLen, serverCertLen, wPublicKeyBlobLen;
if (!settings->encryption)
{
settings->encryption_method = ENCRYPTION_METHOD_NONE;
settings->encryption_level = ENCRYPTION_LEVEL_NONE;
}
else if ((settings->encryption_method & ENCRYPTION_METHOD_FIPS) != 0)
{
settings->encryption_method = ENCRYPTION_METHOD_FIPS;
}
else if ((settings->encryption_method & ENCRYPTION_METHOD_128BIT) != 0)
{
settings->encryption_method = ENCRYPTION_METHOD_128BIT;
}
else if ((settings->encryption_method & ENCRYPTION_METHOD_40BIT) != 0)
{
settings->encryption_method = ENCRYPTION_METHOD_40BIT;
}
if (settings->encryption_method != ENCRYPTION_METHOD_NONE)
settings->encryption_level = ENCRYPTION_LEVEL_CLIENT_COMPATIBLE;
headerLen = 12;
keyLen = 0;
wPublicKeyBlobLen = 0;
serverRandomLen = 0;
serverCertLen = 0;
if (settings->encryption_method != ENCRYPTION_METHOD_NONE ||
settings->encryption_level != ENCRYPTION_LEVEL_NONE)
{
serverRandomLen = 32;
keyLen = settings->server_key->modulus.length;
expLen = sizeof(settings->server_key->exponent);
wPublicKeyBlobLen = 4; /* magic (RSA1) */
wPublicKeyBlobLen += 4; /* keylen */
wPublicKeyBlobLen += 4; /* bitlen */
wPublicKeyBlobLen += 4; /* datalen */
wPublicKeyBlobLen += expLen;
wPublicKeyBlobLen += keyLen;
wPublicKeyBlobLen += 8; /* 8 bytes of zero padding */
serverCertLen = 4; /* dwVersion */
serverCertLen += 4; /* dwSigAlgId */
serverCertLen += 4; /* dwKeyAlgId */
serverCertLen += 2; /* wPublicKeyBlobType */
serverCertLen += 2; /* wPublicKeyBlobLen */
serverCertLen += wPublicKeyBlobLen;
serverCertLen += 2; /* wSignatureBlobType */
serverCertLen += 2; /* wSignatureBlobLen */
serverCertLen += sizeof(encryptedSignature); /* SignatureBlob */
serverCertLen += 8; /* 8 bytes of zero padding */
headerLen += sizeof(serverRandomLen);
headerLen += sizeof(serverCertLen);
headerLen += serverRandomLen;
headerLen += serverCertLen;
}
gcc_write_user_data_header(s, SC_SECURITY, headerLen);
stream_write_uint32(s, settings->encryption_method); /* encryptionMethod */
stream_write_uint32(s, settings->encryption_level); /* encryptionLevel */
if (settings->encryption_method == ENCRYPTION_METHOD_NONE &&
settings->encryption_level == ENCRYPTION_LEVEL_NONE)
{
return;
}
stream_write_uint32(s, serverRandomLen); /* serverRandomLen */
stream_write_uint32(s, serverCertLen); /* serverCertLen */
freerdp_blob_alloc(settings->server_random, serverRandomLen);
crypto_nonce(settings->server_random->data, serverRandomLen);
stream_write(s, settings->server_random->data, serverRandomLen);
sigData = stream_get_tail(s);
stream_write_uint32(s, CERT_CHAIN_VERSION_1); /* dwVersion (4 bytes) */
stream_write_uint32(s, SIGNATURE_ALG_RSA); /* dwSigAlgId */
stream_write_uint32(s, KEY_EXCHANGE_ALG_RSA); /* dwKeyAlgId */
stream_write_uint16(s, BB_RSA_KEY_BLOB); /* wPublicKeyBlobType */
stream_write_uint16(s, wPublicKeyBlobLen); /* wPublicKeyBlobLen */
stream_write(s, "RSA1", 4); /* magic */
stream_write_uint32(s, keyLen + 8); /* keylen */
stream_write_uint32(s, keyLen * 8); /* bitlen */
stream_write_uint32(s, keyLen - 1); /* datalen */
stream_write(s, settings->server_key->exponent, expLen);
stream_write(s, settings->server_key->modulus.data, keyLen);
stream_write_zero(s, 8);
sigDataLen = stream_get_tail(s) - sigData;
stream_write_uint16(s, BB_RSA_SIGNATURE_BLOB); /* wSignatureBlobType */
stream_write_uint16(s, keyLen + 8); /* wSignatureBlobLen */
memcpy(signature, initial_signature, sizeof(initial_signature));
md5 = crypto_md5_init();
crypto_md5_update(md5, sigData, sigDataLen);
crypto_md5_final(md5, signature);
crypto_rsa_private_encrypt(signature, sizeof(signature), TSSK_KEY_LENGTH,
tssk_modulus, tssk_privateExponent, encryptedSignature);
stream_write(s, encryptedSignature, sizeof(encryptedSignature));
stream_write_zero(s, 8);
}