Allow server public key to be anywhere from 512 bits to 2048 bits.
(Vista Beta 2 uses a 2048 bit key) git-svn-id: svn://svn.code.sf.net/p/rdesktop/code/trunk/rdesktop@1236 423420c4-83ab-492f-b58f-81f9feb106b5
This commit is contained in:
parent
997e354a24
commit
69692c7014
@ -62,6 +62,7 @@ enum MCS_PDU_TYPE
|
|||||||
/* RDP secure transport constants */
|
/* RDP secure transport constants */
|
||||||
#define SEC_RANDOM_SIZE 32
|
#define SEC_RANDOM_SIZE 32
|
||||||
#define SEC_MODULUS_SIZE 64
|
#define SEC_MODULUS_SIZE 64
|
||||||
|
#define SEC_MAX_MODULUS_SIZE 256
|
||||||
#define SEC_PADDING_SIZE 8
|
#define SEC_PADDING_SIZE 8
|
||||||
#define SEC_EXPONENT_SIZE 4
|
#define SEC_EXPONENT_SIZE 4
|
||||||
|
|
||||||
|
71
secure.c
71
secure.c
@ -46,13 +46,14 @@ static int rc4_key_len;
|
|||||||
static RC4_KEY rc4_decrypt_key;
|
static RC4_KEY rc4_decrypt_key;
|
||||||
static RC4_KEY rc4_encrypt_key;
|
static RC4_KEY rc4_encrypt_key;
|
||||||
static RSA *server_public_key;
|
static RSA *server_public_key;
|
||||||
|
static uint32 server_public_key_len;
|
||||||
|
|
||||||
static uint8 sec_sign_key[16];
|
static uint8 sec_sign_key[16];
|
||||||
static uint8 sec_decrypt_key[16];
|
static uint8 sec_decrypt_key[16];
|
||||||
static uint8 sec_encrypt_key[16];
|
static uint8 sec_encrypt_key[16];
|
||||||
static uint8 sec_decrypt_update_key[16];
|
static uint8 sec_decrypt_update_key[16];
|
||||||
static uint8 sec_encrypt_update_key[16];
|
static uint8 sec_encrypt_update_key[16];
|
||||||
static uint8 sec_crypted_random[SEC_MODULUS_SIZE];
|
static uint8 sec_crypted_random[SEC_MAX_MODULUS_SIZE];
|
||||||
|
|
||||||
uint16 g_server_rdp_version = 0;
|
uint16 g_server_rdp_version = 0;
|
||||||
|
|
||||||
@ -297,14 +298,14 @@ reverse(uint8 * p, int len)
|
|||||||
|
|
||||||
/* Perform an RSA public key encryption operation */
|
/* Perform an RSA public key encryption operation */
|
||||||
static void
|
static void
|
||||||
sec_rsa_encrypt(uint8 * out, uint8 * in, int len, uint8 * modulus, uint8 * exponent)
|
sec_rsa_encrypt(uint8 * out, uint8 * in, int len, uint32 modulus_size, uint8 * modulus, uint8 * exponent)
|
||||||
{
|
{
|
||||||
BN_CTX *ctx;
|
BN_CTX *ctx;
|
||||||
BIGNUM mod, exp, x, y;
|
BIGNUM mod, exp, x, y;
|
||||||
uint8 inr[SEC_MODULUS_SIZE];
|
uint8 inr[SEC_MAX_MODULUS_SIZE];
|
||||||
int outlen;
|
int outlen;
|
||||||
|
|
||||||
reverse(modulus, SEC_MODULUS_SIZE);
|
reverse(modulus, modulus_size);
|
||||||
reverse(exponent, SEC_EXPONENT_SIZE);
|
reverse(exponent, SEC_EXPONENT_SIZE);
|
||||||
memcpy(inr, in, len);
|
memcpy(inr, in, len);
|
||||||
reverse(inr, len);
|
reverse(inr, len);
|
||||||
@ -315,14 +316,14 @@ sec_rsa_encrypt(uint8 * out, uint8 * in, int len, uint8 * modulus, uint8 * expon
|
|||||||
BN_init(&x);
|
BN_init(&x);
|
||||||
BN_init(&y);
|
BN_init(&y);
|
||||||
|
|
||||||
BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod);
|
BN_bin2bn(modulus, modulus_size, &mod);
|
||||||
BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp);
|
BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp);
|
||||||
BN_bin2bn(inr, len, &x);
|
BN_bin2bn(inr, len, &x);
|
||||||
BN_mod_exp(&y, &x, &exp, &mod, ctx);
|
BN_mod_exp(&y, &x, &exp, &mod, ctx);
|
||||||
outlen = BN_bn2bin(&y, out);
|
outlen = BN_bn2bin(&y, out);
|
||||||
reverse(out, outlen);
|
reverse(out, outlen);
|
||||||
if (outlen < SEC_MODULUS_SIZE)
|
if (outlen < modulus_size)
|
||||||
memset(out + outlen, 0, SEC_MODULUS_SIZE - outlen);
|
memset(out + outlen, 0, modulus_size - outlen);
|
||||||
|
|
||||||
BN_free(&y);
|
BN_free(&y);
|
||||||
BN_clear_free(&x);
|
BN_clear_free(&x);
|
||||||
@ -388,14 +389,14 @@ sec_send(STREAM s, uint32 flags)
|
|||||||
static void
|
static void
|
||||||
sec_establish_key(void)
|
sec_establish_key(void)
|
||||||
{
|
{
|
||||||
uint32 length = SEC_MODULUS_SIZE + SEC_PADDING_SIZE;
|
uint32 length = server_public_key_len + SEC_PADDING_SIZE;
|
||||||
uint32 flags = SEC_CLIENT_RANDOM;
|
uint32 flags = SEC_CLIENT_RANDOM;
|
||||||
STREAM s;
|
STREAM s;
|
||||||
|
|
||||||
s = sec_init(flags, 76);
|
s = sec_init(flags, length+4);
|
||||||
|
|
||||||
out_uint32_le(s, length);
|
out_uint32_le(s, length);
|
||||||
out_uint8p(s, sec_crypted_random, SEC_MODULUS_SIZE);
|
out_uint8p(s, sec_crypted_random, server_public_key_len);
|
||||||
out_uint8s(s, SEC_PADDING_SIZE);
|
out_uint8s(s, SEC_PADDING_SIZE);
|
||||||
|
|
||||||
s_mark_end(s);
|
s_mark_end(s);
|
||||||
@ -507,16 +508,18 @@ sec_parse_public_key(STREAM s, uint8 ** modulus, uint8 ** exponent)
|
|||||||
}
|
}
|
||||||
|
|
||||||
in_uint32_le(s, modulus_len);
|
in_uint32_le(s, modulus_len);
|
||||||
if (modulus_len != SEC_MODULUS_SIZE + SEC_PADDING_SIZE)
|
modulus_len -= SEC_PADDING_SIZE;
|
||||||
|
if ((modulus_len < 64) || (modulus_len > SEC_MAX_MODULUS_SIZE))
|
||||||
{
|
{
|
||||||
error("modulus len 0x%x\n", modulus_len);
|
error("Bad server public key size (%u bits)\n", modulus_len*8);
|
||||||
return False;
|
return False;
|
||||||
}
|
}
|
||||||
|
|
||||||
in_uint8s(s, 8); /* modulus_bits, unknown */
|
in_uint8s(s, 8); /* modulus_bits, unknown */
|
||||||
in_uint8p(s, *exponent, SEC_EXPONENT_SIZE);
|
in_uint8p(s, *exponent, SEC_EXPONENT_SIZE);
|
||||||
in_uint8p(s, *modulus, SEC_MODULUS_SIZE);
|
in_uint8p(s, *modulus, modulus_len);
|
||||||
in_uint8s(s, SEC_PADDING_SIZE);
|
in_uint8s(s, SEC_PADDING_SIZE);
|
||||||
|
server_public_key_len = modulus_len;
|
||||||
|
|
||||||
return s_check(s);
|
return s_check(s);
|
||||||
}
|
}
|
||||||
@ -544,9 +547,15 @@ sec_parse_x509_key(X509 * cert)
|
|||||||
}
|
}
|
||||||
|
|
||||||
server_public_key = RSAPublicKey_dup((RSA *) epk->pkey.ptr);
|
server_public_key = RSAPublicKey_dup((RSA *) epk->pkey.ptr);
|
||||||
|
|
||||||
EVP_PKEY_free(epk);
|
EVP_PKEY_free(epk);
|
||||||
|
|
||||||
|
server_public_key_len = RSA_size(server_public_key);
|
||||||
|
if ((server_public_key_len < 64) || (server_public_key_len > SEC_MAX_MODULUS_SIZE))
|
||||||
|
{
|
||||||
|
error("Bad server public key size (%u bits)\n", server_public_key_len*8);
|
||||||
|
return False;
|
||||||
|
}
|
||||||
|
|
||||||
return True;
|
return True;
|
||||||
}
|
}
|
||||||
|
|
||||||
@ -719,7 +728,6 @@ sec_process_crypt_info(STREAM s)
|
|||||||
uint8 *server_random, *modulus, *exponent;
|
uint8 *server_random, *modulus, *exponent;
|
||||||
uint8 client_random[SEC_RANDOM_SIZE];
|
uint8 client_random[SEC_RANDOM_SIZE];
|
||||||
uint32 rc4_key_size;
|
uint32 rc4_key_size;
|
||||||
uint8 inr[SEC_MODULUS_SIZE];
|
|
||||||
|
|
||||||
if (!sec_parse_crypt_info(s, &rc4_key_size, &server_random, &modulus, &exponent))
|
if (!sec_parse_crypt_info(s, &rc4_key_size, &server_random, &modulus, &exponent))
|
||||||
{
|
{
|
||||||
@ -728,29 +736,30 @@ sec_process_crypt_info(STREAM s)
|
|||||||
}
|
}
|
||||||
|
|
||||||
DEBUG(("Generating client random\n"));
|
DEBUG(("Generating client random\n"));
|
||||||
/* Generate a client random, and hence determine encryption keys */
|
|
||||||
/* This is what the MS client do: */
|
|
||||||
memset(inr, 0, SEC_RANDOM_SIZE);
|
|
||||||
/* *ARIGL!* Plaintext attack, anyone?
|
|
||||||
I tried doing:
|
|
||||||
generate_random(inr);
|
|
||||||
..but that generates connection errors now and then (yes,
|
|
||||||
"now and then". Something like 0 to 3 attempts needed before a
|
|
||||||
successful connection. Nice. Not!
|
|
||||||
*/
|
|
||||||
|
|
||||||
generate_random(client_random);
|
generate_random(client_random);
|
||||||
|
|
||||||
if (NULL != server_public_key)
|
if (NULL != server_public_key)
|
||||||
{ /* Which means we should use
|
{ /* Which means we should use
|
||||||
RDP5-style encryption */
|
RDP5-style encryption */
|
||||||
|
uint8 inr[SEC_MAX_MODULUS_SIZE];
|
||||||
|
uint32 padding_len = server_public_key_len - SEC_RANDOM_SIZE;
|
||||||
|
|
||||||
memcpy(inr + SEC_RANDOM_SIZE, client_random, SEC_RANDOM_SIZE);
|
/* This is what the MS client do: */
|
||||||
reverse(inr + SEC_RANDOM_SIZE, SEC_RANDOM_SIZE);
|
memset(inr, 0, padding_len);
|
||||||
|
/* *ARIGL!* Plaintext attack, anyone?
|
||||||
|
I tried doing:
|
||||||
|
generate_random(inr);
|
||||||
|
..but that generates connection errors now and then (yes,
|
||||||
|
"now and then". Something like 0 to 3 attempts needed before a
|
||||||
|
successful connection. Nice. Not!
|
||||||
|
*/
|
||||||
|
memcpy(inr + padding_len, client_random, SEC_RANDOM_SIZE);
|
||||||
|
reverse(inr + padding_len, SEC_RANDOM_SIZE);
|
||||||
|
|
||||||
RSA_public_encrypt(SEC_MODULUS_SIZE,
|
RSA_public_encrypt(server_public_key_len,
|
||||||
inr, sec_crypted_random, server_public_key, RSA_NO_PADDING);
|
inr, sec_crypted_random, server_public_key, RSA_NO_PADDING);
|
||||||
|
|
||||||
reverse(sec_crypted_random, SEC_MODULUS_SIZE);
|
reverse(sec_crypted_random, server_public_key_len);
|
||||||
|
|
||||||
RSA_free(server_public_key);
|
RSA_free(server_public_key);
|
||||||
server_public_key = NULL;
|
server_public_key = NULL;
|
||||||
@ -758,7 +767,7 @@ sec_process_crypt_info(STREAM s)
|
|||||||
else
|
else
|
||||||
{ /* RDP4-style encryption */
|
{ /* RDP4-style encryption */
|
||||||
sec_rsa_encrypt(sec_crypted_random,
|
sec_rsa_encrypt(sec_crypted_random,
|
||||||
client_random, SEC_RANDOM_SIZE, modulus, exponent);
|
client_random, SEC_RANDOM_SIZE, server_public_key_len, modulus, exponent);
|
||||||
}
|
}
|
||||||
sec_generate_keys(client_random, server_random, rc4_key_size);
|
sec_generate_keys(client_random, server_random, rc4_key_size);
|
||||||
}
|
}
|
||||||
|
Loading…
Reference in New Issue
Block a user