mbedcrypto: Make bignum_bin2bn behave like others

Signed-off-by: Simo Sorce <simo@redhat.com>
Reviewed-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

include/libssh/libmbedcrypto.h

@@ -92,8 +92,12 @@ int ssh_mbedcry_hex2bn(bignum *dest, char *data);
 #define bignum_ctx_invalid(ctx) (ctx == NULL?0:1)
 #define bignum_set_word(bn, n) (mbedtls_mpi_lset(bn, n)==0?1:0) /* TODO fix
                                                           overflow/underflow */
-#define bignum_bin2bn(data, datalen, bn) mbedtls_mpi_read_binary(bn, data, \
-        datalen)
+#define bignum_bin2bn(data, datalen, bn) do { \
+    *(bn) = bignum_new(); \
+    if (*(bn) != NULL) { \
+        mbedtls_mpi_read_binary(*(bn), data, datalen); \
+    } \
+    } while(0)
 #define bignum_bn2dec(num) ssh_mbedcry_bn2num(num, 10)
 #define bignum_dec2bn(data, bn) mbedtls_mpi_read_string(bn, 10, data)
 #define bignum_bn2hex(num, dest) (*dest)=ssh_mbedcry_bn2num(num, 16)

src/bignum.c

@@ -71,13 +71,7 @@ bignum ssh_make_string_bn(ssh_string string)
             len * 8, len);
 #endif /* DEBUG_CRYPTO */
 
-#if defined HAVE_LIBMBEDCRYPTO
-    bn = bignum_new();
-    bignum_bin2bn(string->data, len, bn);
-#else
-    // FIXME
     bignum_bin2bn(string->data, len, &bn);
-#endif
 
     return bn;
 }

src/curve25519.c

@@ -88,14 +88,6 @@ int ssh_client_curve25519_init(ssh_session session){
 static int ssh_curve25519_build_k(ssh_session session) {
   ssh_curve25519_pubkey k;
 
-#if defined HAVE_LIBMBEDCRYPTO
-  session->next_crypto->k = bignum_new();
-
-  if (session->next_crypto->k == NULL) {
-    return SSH_ERROR;
-  }
-#endif
-
   if (session->server)
 	  crypto_scalarmult(k, session->next_crypto->curve25519_privkey,
 			  session->next_crypto->curve25519_client_pubkey);
@@ -103,12 +95,7 @@ static int ssh_curve25519_build_k(ssh_session session) {
 	  crypto_scalarmult(k, session->next_crypto->curve25519_privkey,
 			  session->next_crypto->curve25519_server_pubkey);
 
-#if defined HAVE_LIBMBEDCRYPTO
-  /* FIXME */
-  bignum_bin2bn(k, CURVE25519_PUBKEY_SIZE, session->next_crypto->k);
-#else
   bignum_bin2bn(k, CURVE25519_PUBKEY_SIZE, &session->next_crypto->k);
-#endif
   if (session->next_crypto->k == NULL) {
     return SSH_ERROR;
   }

src/dh.c

@@ -247,20 +247,6 @@ int ssh_dh_init(void)
         goto error;
     }
 
-#if defined(HAVE_LIBMBEDCRYPTO)
-    /* FIXME */
-    p_group1 = bignum_new();
-    bignum_bin2bn(p_group1_value, P_GROUP1_LEN, p_group1);
-
-    p_group14 = bignum_new();
-    bignum_bin2bn(p_group14_value, P_GROUP14_LEN, p_group14);
-
-    p_group16 = bignum_new();
-    bignum_bin2bn(p_group16_value, P_GROUP16_LEN, p_group16);
-
-    p_group18 = bignum_new();
-    bignum_bin2bn(p_group18_value, P_GROUP18_LEN, p_group18);
-#else
     bignum_bin2bn(p_group1_value, P_GROUP1_LEN, &p_group1);
     if (p_group1 == NULL) {
         goto error;
@@ -278,8 +264,6 @@ int ssh_dh_init(void)
         goto error;
     }
 
-#endif
-
     dh_crypto_initialized = 1;
 
     return 0;