Updated the SRP implementation to follow the latest draft.

1 files changed, 142 insertions, 1 deletions

diff --git a/libextra/auth_srp.c b/libextra/auth_srp.c
index 4c62e5963e..77e46fa7ae 100644
--- a/libextra/auth_srp.c
+++ b/libextra/auth_srp.c
@@ -337,6 +337,7 @@ int _gnutls_proc_srp_client_kx(gnutls_session state, opaque * data, size_t _data
 	return 0;
 }
 
+
 /* Checks if b%n==0 which is a fatal srp error.
  * Returns a proper error code in that case, and 0 when
  * all are ok.
@@ -359,6 +360,131 @@ GNUTLS_MPI r = _gnutls_mpi_alloc_like(b);
 	return 0;
 }
 
+/* Static parameters according to draft-ietf-tls-srp-05
+ */
+static const unsigned char srp_params_1024[] = {
+ 0xEE, 0xAF, 0x0A, 0xB9, 0xAD, 0xB3, 0x8D, 0xD6, 
+ 0x9C, 0x33, 0xF8, 0x0A, 0xFA, 0x8F, 0xC5, 0xE8, 
+ 0x60, 0x72, 0x61, 0x87, 0x75, 0xFF, 0x3C, 0x0B,
+ 0x9E, 0xA2, 0x31, 0x4C, 0x9C, 0x25, 0x65, 0x76,
+ 0xD6, 0x74, 0xDF, 0x74, 0x96, 0xEA, 0x81, 0xD3,
+ 0x38, 0x3B, 0x48, 0x13, 0xD6, 0x92, 0xC6, 0xE0,
+ 0xE0, 0xD5, 0xD8, 0xE2, 0x50, 0xB9, 0x8B, 0xE4,
+ 0x8E, 0x49, 0x5C, 0x1D, 0x60, 0x89, 0xDA, 0xD1,
+ 0x5D, 0xC7, 0xD7, 0xB4, 0x61, 0x54, 0xD6, 0xB6,
+ 0xCE, 0x8E, 0xF4, 0xAD, 0x69, 0xB1, 0x5D, 0x49,
+ 0x82, 0x55, 0x9B, 0x29, 0x7B, 0xCF, 0x18, 0x85,
+ 0xC5, 0x29, 0xF5, 0x66, 0x66, 0x0E, 0x57, 0xEC,
+ 0x68, 0xED, 0xBC, 0x3C, 0x05, 0x72, 0x6C, 0xC0,
+ 0x2F, 0xD4, 0xCB, 0xF4, 0x97, 0x6E, 0xAA, 0x9A,
+ 0xFD, 0x51, 0x38, 0xFE, 0x83, 0x76, 0x43, 0x5B,
+ 0x9F, 0xC6, 0x1D, 0x2F, 0xC0, 0xEB, 0x06, 0xE3
+};
+
+static const unsigned char srp_generator = 0x02;
+
+static const unsigned char srp_params_1536[] = {
+ 0x9D, 0xEF, 0x3C, 0xAF, 0xB9, 0x39, 0x27, 0x7A, 0xB1,
+ 0xF1, 0x2A, 0x86, 0x17, 0xA4, 0x7B, 0xBB, 0xDB, 0xA5,
+ 0x1D, 0xF4, 0x99, 0xAC, 0x4C, 0x80, 0xBE, 0xEE, 0xA9,
+ 0x61, 0x4B, 0x19, 0xCC, 0x4D, 0x5F, 0x4F, 0x5F, 0x55,
+ 0x6E, 0x27, 0xCB, 0xDE, 0x51, 0xC6, 0xA9, 0x4B, 0xE4,
+ 0x60, 0x7A, 0x29, 0x15, 0x58, 0x90, 0x3B, 0xA0, 0xD0,
+ 0xF8, 0x43, 0x80, 0xB6, 0x55, 0xBB, 0x9A, 0x22, 0xE8,
+ 0xDC, 0xDF, 0x02, 0x8A, 0x7C, 0xEC, 0x67, 0xF0, 0xD0,
+ 0x81, 0x34, 0xB1, 0xC8, 0xB9, 0x79, 0x89, 0x14, 0x9B,
+ 0x60, 0x9E, 0x0B, 0xE3, 0xBA, 0xB6, 0x3D, 0x47, 0x54,
+ 0x83, 0x81, 0xDB, 0xC5, 0xB1, 0xFC, 0x76, 0x4E, 0x3F,
+ 0x4B, 0x53, 0xDD, 0x9D, 0xA1, 0x15, 0x8B, 0xFD, 0x3E,
+ 0x2B, 0x9C, 0x8C, 0xF5, 0x6E, 0xDF, 0x01, 0x95, 0x39,
+ 0x34, 0x96, 0x27, 0xDB, 0x2F, 0xD5, 0x3D, 0x24, 0xB7,
+ 0xC4, 0x86, 0x65, 0x77, 0x2E, 0x43, 0x6C, 0x7F, 0x8C,
+ 0xE4, 0x42, 0x73, 0x4A, 0xF7, 0xCC, 0xB7, 0xAE, 0x83,
+ 0x7C, 0x26, 0x4A, 0xE3, 0xA9, 0xBE, 0xB8, 0x7F, 0x8A,
+ 0x2F, 0xE9, 0xB8, 0xB5, 0x29, 0x2E, 0x5A, 0x02, 0x1F,
+ 0xFF, 0x5E, 0x91, 0x47, 0x9E, 0x8C, 0xE7, 0xA2, 0x8C,
+ 0x24, 0x42, 0xC6, 0xF3, 0x15, 0x18, 0x0F, 0x93, 0x49, 
+ 0x9A, 0x23, 0x4D, 0xCF, 0x76, 0xE3, 0xFE, 0xD1, 0x35,
+ 0xF9, 0xBB
+};
+
+static const unsigned char srp_params_2048[] = {
+ 0xAC, 0x6B, 0xDB, 0x41, 0x32, 0x4A, 0x9A, 0x9B, 0xF1,
+ 0x66, 0xDE, 0x5E, 0x13, 0x89, 0x58, 0x2F, 0xAF, 0x72,
+ 0xB6, 0x65, 0x19, 0x87, 0xEE, 0x07, 0xFC, 0x31, 0x92,
+ 0x94, 0x3D, 0xB5, 0x60, 0x50, 0xA3, 0x73, 0x29, 0xCB,
+ 0xB4, 0xA0, 0x99, 0xED, 0x81, 0x93, 0xE0, 0x75, 0x77, 
+ 0x67, 0xA1, 0x3D, 0xD5, 0x23, 0x12, 0xAB, 0x4B, 0x03,
+ 0x31, 0x0D, 0xCD, 0x7F, 0x48, 0xA9, 0xDA, 0x04, 0xFD,
+ 0x50, 0xE8, 0x08, 0x39, 0x69, 0xED, 0xB7, 0x67, 0xB0,
+ 0xCF, 0x60, 0x95, 0x17, 0x9A, 0x16, 0x3A, 0xB3, 0x66,
+ 0x1A, 0x05, 0xFB, 0xD5, 0xFA, 0xAA, 0xE8, 0x29, 0x18,
+ 0xA9, 0x96, 0x2F, 0x0B, 0x93, 0xB8, 0x55, 0xF9, 0x79,
+ 0x93, 0xEC, 0x97, 0x5E, 0xEA, 0xA8, 0x0D, 0x74, 0x0A,
+ 0xDB, 0xF4, 0xFF, 0x74, 0x73, 0x59, 0xD0, 0x41, 0xD5,
+ 0xC3, 0x3E, 0xA7, 0x1D, 0x28, 0x1E, 0x44, 0x6B, 0x14,
+ 0x77, 0x3B, 0xCA, 0x97, 0xB4, 0x3A, 0x23, 0xFB, 0x80,
+ 0x16, 0x76, 0xBD, 0x20, 0x7A, 0x43, 0x6C, 0x64, 0x81,
+ 0xF1, 0xD2, 0xB9, 0x07, 0x87, 0x17, 0x46, 0x1A, 0x5B,
+ 0x9D, 0x32, 0xE6, 0x88, 0xF8, 0x77, 0x48, 0x54, 0x45,
+ 0x23, 0xB5, 0x24, 0xB0, 0xD5, 0x7D, 0x5E, 0xA7, 0x7A,
+ 0x27, 0x75, 0xD2, 0xEC, 0xFA, 0x03, 0x2C, 0xFB, 0xDB,
+ 0xF5, 0x2F, 0xB3, 0x78, 0x61, 0x60, 0x27, 0x90, 0x04,
+ 0xE5, 0x7A, 0xE6, 0xAF, 0x87, 0x4E, 0x73, 0x03, 0xCE,
+ 0x53, 0x29, 0x9C, 0xCC, 0x04, 0x1C, 0x7B, 0xC3, 0x08,
+ 0xD8, 0x2A, 0x56, 0x98, 0xF3, 0xA8, 0xD0, 0xC3, 0x82,
+ 0x71, 0xAE, 0x35, 0xF8, 0xE9, 0xDB, 0xFB, 0xB6, 0x94,
+ 0xB5, 0xC8, 0x03, 0xD8, 0x9F, 0x7A, 0xE4, 0x35, 0xDE,
+ 0x23, 0x6D, 0x52, 0x5F, 0x54, 0x75, 0x9B, 0x65, 0xE3,
+ 0x72, 0xFC, 0xD6, 0x8E, 0xF2, 0x0F, 0xA7, 0x11, 0x1F,
+ 0x9E, 0x4A, 0xFF, 0x73
+};
+
+/* Check if G and N are parameters from the SRP draft.
+ */
+static int check_g_n( const opaque* g, size_t n_g, 
+	const opaque* n, size_t n_n) 
+{
+
+	if (n_g != 1 || g[0] != srp_generator) 
+		return GNUTLS_E_ILLEGAL_SRP_PARAMS;
+
+	if (n_n == sizeof(srp_params_1024) &&
+			memcmp( srp_params_1024, n, n_n)==0) {
+		return 0;
+	}
+
+	if (n_n == sizeof(srp_params_1536) &&
+			memcmp( srp_params_1536, n, n_n)==0) {
+		return 0;
+	}
+
+	if (n_n == sizeof(srp_params_2048) &&
+			memcmp( srp_params_2048, n, n_n)==0) {
+		return 0;
+	}
+
+	return GNUTLS_E_ILLEGAL_SRP_PARAMS;
+}
+
+/* Check if N is a prime and G a generator of the
+ * group.
+ */
+static int group_check_g_n( GNUTLS_MPI g, GNUTLS_MPI n) 
+{
+	if (gcry_prime_check( n, 0) != 0) {
+		gnutls_assert();
+		return GNUTLS_E_ILLEGAL_SRP_PARAMS;
+	}
+	
+	/* We should also check whether g is a generator,
+	 * but this is not possible.
+	 */
+	
+	return 0;
+
+}
+
 /* receive the key exchange message ( n, g, s, B) 
  */
 int _gnutls_proc_srp_server_kx(gnutls_session state, opaque * data, size_t _data_size)
@@ -452,7 +578,22 @@ int _gnutls_proc_srp_server_kx(gnutls_session state, opaque * data, size_t _data
 		gnutls_assert();
 		return GNUTLS_E_MPI_SCAN_FAILED;
 	}
-	
+
+
+	/* Check if the g and n are from the SRP
+	 * draft. Otherwise check if N is a prime and G
+	 * a generator.
+	 */
+	if ( (ret = check_g_n( data_g, _n_g, data_n, _n_n)) < 0) {
+		_gnutls_x509_log("Checking the SRP group parameters.\n");
+		if ( (ret = group_check_g_n( G, N)) < 0) {
+			gnutls_assert();
+			return ret;
+		}
+	}
+
+	/* Checks if b % n == 0
+	 */
 	if ( (ret = check_b_mod_n( B, N)) < 0) {
 		gnutls_assert();
 		return ret;