BOOL license_encrypt_premaster_secret(rdpLicense* license)
{
BYTE* EncryptedPremasterSecret;
if (!license_get_server_rsa_public_key(license))
return FALSE;
#ifdef WITH_DEBUG_LICENSE
WLog_DBG(TAG, "Modulus (%d bits):", license->ModulusLength * 8);
winpr_HexDump(TAG, WLOG_DEBUG, license->Modulus, license->ModulusLength);
WLog_DBG(TAG, "Exponent:");
winpr_HexDump(TAG, WLOG_DEBUG, license->Exponent, 4);
#endif
EncryptedPremasterSecret = (BYTE*) calloc(1, license->ModulusLength);
if (!EncryptedPremasterSecret)
return FALSE;
license->EncryptedPremasterSecret->type = BB_RANDOM_BLOB;
license->EncryptedPremasterSecret->length = PREMASTER_SECRET_LENGTH;
#ifndef LICENSE_NULL_PREMASTER_SECRET
license->EncryptedPremasterSecret->length =
crypto_rsa_public_encrypt(license->PremasterSecret, PREMASTER_SECRET_LENGTH,
license->ModulusLength, license->Modulus, license->Exponent, EncryptedPremasterSecret);
#endif
license->EncryptedPremasterSecret->data = EncryptedPremasterSecret;
return TRUE;
}
void license_encrypt_premaster_secret(rdpLicense* license)
{
BYTE* EncryptedPremasterSecret;
license_get_server_rsa_public_key(license);
#ifdef WITH_DEBUG_LICENSE
fprintf(stderr, "Modulus (%d bits):\n", license->ModulusLength * 8);
winpr_HexDump(license->Modulus, license->ModulusLength);
fprintf(stderr, "\n");
fprintf(stderr, "Exponent:\n");
winpr_HexDump(license->Exponent, 4);
fprintf(stderr, "\n");
#endif
EncryptedPremasterSecret = (BYTE*) malloc(license->ModulusLength);
ZeroMemory(EncryptedPremasterSecret, license->ModulusLength);
license->EncryptedPremasterSecret->type = BB_RANDOM_BLOB;
license->EncryptedPremasterSecret->length = PREMASTER_SECRET_LENGTH;
#ifndef LICENSE_NULL_PREMASTER_SECRET
license->EncryptedPremasterSecret->length =
crypto_rsa_public_encrypt(license->PremasterSecret, PREMASTER_SECRET_LENGTH,
license->ModulusLength, license->Modulus, license->Exponent, EncryptedPremasterSecret);
#endif
license->EncryptedPremasterSecret->data = EncryptedPremasterSecret;
}
void license_encrypt_premaster_secret(rdpLicense* license)
{
uint8* encrypted_premaster_secret;
#if 0
int key_length;
uint8* modulus;
uint8* exponent;
rdpCertificate *certificate;
if (license->server_certificate->length)
certificate = license->certificate;
else
certificate = license->rdp->settings->server_cert;
exponent = certificate->cert_info.exponent;
modulus = certificate->cert_info.modulus.data;
key_length = certificate->cert_info.modulus.length;
#ifdef WITH_DEBUG_LICENSE
printf("modulus (%d bits):\n", key_length * 8);
freerdp_hexdump(modulus, key_length);
printf("exponent:\n");
freerdp_hexdump(exponent, 4);
#endif
encrypted_premaster_secret = (uint8*) xmalloc(MODULUS_MAX_SIZE);
memset(encrypted_premaster_secret, 0, MODULUS_MAX_SIZE);
crypto_rsa_public_encrypt(license->premaster_secret, PREMASTER_SECRET_LENGTH,
key_length, modulus, exponent, encrypted_premaster_secret);
license->encrypted_premaster_secret->type = BB_RANDOM_BLOB;
license->encrypted_premaster_secret->length = PREMASTER_SECRET_LENGTH;
license->encrypted_premaster_secret->data = encrypted_premaster_secret;
#else
encrypted_premaster_secret = (uint8*) xmalloc(MODULUS_MAX_SIZE);
memset(encrypted_premaster_secret, 0, MODULUS_MAX_SIZE);
license->encrypted_premaster_secret->type = BB_RANDOM_BLOB;
license->encrypted_premaster_secret->length = PREMASTER_SECRET_LENGTH;
license->encrypted_premaster_secret->data = encrypted_premaster_secret;
#endif
}
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 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;
}
