Error checkings for signature computation.

[silc.git] / lib / silcske / silcske.c

diff --git a/lib/silcske/silcske.c b/lib/silcske/silcske.c
index c423b27cb6fd3976d1ca724a55aa6319896dd18c..6535f55d4d9d1c54d12701b357edcc3895c56ef6 100644 (file)
--- a/lib/silcske/silcske.c
+++ b/lib/silcske/silcske.c
@@ -382,7 +382,7 @@ SilcSKEStatus silc_ske_initiator_phase_2(SilcSKE ske,
 
   /* Compute signature data if we are doing mutual authentication */
   if (private_key && ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL) {
-    unsigned char hash[32], sign[1024];
+    unsigned char hash[32], sign[2048];
     SilcUInt32 hash_len, sign_len;
 
     SILC_LOG_DEBUG(("We are doing mutual authentication"));
@@ -397,7 +397,16 @@ SilcSKEStatus silc_ske_initiator_phase_2(SilcSKE ske,
     /* Sign the hash value */
     silc_pkcs_private_key_data_set(ske->prop->pkcs, private_key->prv, 
                                   private_key->prv_len);
-    silc_pkcs_sign(ske->prop->pkcs, hash, hash_len, sign, &sign_len);
+    if (silc_pkcs_get_key_len(ske->prop->pkcs) > sizeof(sign) - 1 ||
+       !silc_pkcs_sign(ske->prop->pkcs, hash, hash_len, sign, &sign_len)) {
+      silc_mp_uninit(x);
+      silc_free(x);
+      silc_mp_uninit(&payload->x);
+      silc_free(payload->pk_data);
+      silc_free(payload);
+      ske->status = status;
+      return status;
+    }
     payload->sign_data = silc_calloc(sign_len, sizeof(unsigned char));
     memcpy(payload->sign_data, sign, sign_len);
     memset(sign, 0, sizeof(sign));
@@ -986,7 +995,7 @@ SilcSKEStatus silc_ske_responder_finish(SilcSKE ske,
   SilcSKEStatus status = SILC_SKE_STATUS_OK;
   SilcBuffer payload_buf;
   SilcMPInt *KEY;
-  unsigned char hash[32], sign[1024], *pk;
+  unsigned char hash[32], sign[2048], *pk;
   SilcUInt32 hash_len, sign_len, pk_len;
 
   SILC_LOG_DEBUG(("Start"));
@@ -1029,7 +1038,9 @@ SilcSKEStatus silc_ske_responder_finish(SilcSKE ske,
     /* Sign the hash value */
     silc_pkcs_private_key_data_set(ske->prop->pkcs, private_key->prv, 
                                   private_key->prv_len);
-    silc_pkcs_sign(ske->prop->pkcs, hash, hash_len, sign, &sign_len);
+    if (silc_pkcs_get_key_len(ske->prop->pkcs) > sizeof(sign) - 1 ||
+       !silc_pkcs_sign(ske->prop->pkcs, hash, hash_len, sign, &sign_len))
+      goto err;
     ske->ke2_payload->sign_data = silc_calloc(sign_len, sizeof(unsigned char));
     memcpy(ske->ke2_payload->sign_data, sign, sign_len);
     memset(sign, 0, sizeof(sign));