From 12cdfae7c3509c98b8e34a57afd00a0326f979eb Mon Sep 17 00:00:00 2001
From: Pekka Riikonen <priikone@silcnet.org>
Date: Fri, 11 Oct 2002 14:07:42 +0000
Subject: [PATCH] 	Error checkings for signature computation.

---
 lib/silccore/silcauth.c  |  5 +++--
 lib/silccrypt/silcpkcs.h |  2 +-
 lib/silcske/silcske.c    | 15 +++++++++++++--
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/lib/silccore/silcauth.c b/lib/silccore/silcauth.c
index 1beacd44..63ad6940 100644
--- a/lib/silccore/silcauth.c
+++ b/lib/silccore/silcauth.c
@@ -241,7 +241,7 @@ SilcBuffer silc_auth_public_key_auth_generate(SilcPublicKey public_key,
 					      const void *id, SilcIdType type)
 {
   unsigned char *randomdata;
-  unsigned char auth_data[1024];
+  unsigned char auth_data[2048];
   SilcUInt32 auth_len;
   unsigned char *tmp;
   SilcUInt32 tmp_len;
@@ -274,7 +274,8 @@ SilcBuffer silc_auth_public_key_auth_generate(SilcPublicKey public_key,
   silc_pkcs_private_key_set(pkcs, private_key);
 
   /* Compute the hash and the signature. */
-  if (!silc_pkcs_sign_with_hash(pkcs, hash, tmp, tmp_len, auth_data,
+  if (silc_pkcs_get_key_len(pkcs) > sizeof(auth_data) - 1 ||
+      !silc_pkcs_sign_with_hash(pkcs, hash, tmp, tmp_len, auth_data,
 				&auth_len)) {
     memset(randomdata, 0, 256);
     memset(tmp, 0, tmp_len);
diff --git a/lib/silccrypt/silcpkcs.h b/lib/silccrypt/silcpkcs.h
index 787424d7..5dfebffe 100644
--- a/lib/silccrypt/silcpkcs.h
+++ b/lib/silccrypt/silcpkcs.h
@@ -271,7 +271,7 @@ unsigned char *silc_pkcs_get_public_key(SilcPKCS pkcs, SilcUInt32 *len);
 unsigned char *silc_pkcs_get_private_key(SilcPKCS pkcs, SilcUInt32 *len);
 SilcUInt32 silc_pkcs_public_key_set(SilcPKCS pkcs, SilcPublicKey public_key);
 SilcUInt32 silc_pkcs_public_key_data_set(SilcPKCS pkcs, unsigned char *pk,
-				     SilcUInt32 pk_len);
+					 SilcUInt32 pk_len);
 int silc_pkcs_private_key_set(SilcPKCS pkcs, SilcPrivateKey private_key);
 int silc_pkcs_private_key_data_set(SilcPKCS pkcs, unsigned char *prv,
 				   SilcUInt32 prv_len);
diff --git a/lib/silcske/silcske.c b/lib/silcske/silcske.c
index 794306d9..6535f55d 100644
--- a/lib/silcske/silcske.c
+++ b/lib/silcske/silcske.c
@@ -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));
@@ -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));
-- 
2.24.0