stun

commit 384eb347ce4ee45bef59e50444208df94bcc8737
parent b807f6d21c67aba0550b205456d46a8054fc06cc
Author: sin <sin@2f30.org>
Date:   Wed, 30 Mar 2016 09:48:26 +0100

use PBKDF2 for key derivation

Diffstat:
M
stun.c
 | 
10
++++------

1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/stun.c b/stun.c
@@ -22,7 +22,7 @@
  * The sender verifies that the correct response was received.
  *
  * All communication is encrypted using a pre-shared symmetric key, currently
- * using aes-256-gcm hashed with sha512.
+ * using aes-256-gcm.  The key is derived with PBKDF2.
  *
  * All tunneled traffic is encapsulated inside the TCP payload.
  * The packet format is shown below:
@@ -166,12 +166,10 @@ revokeprivs(void)
 int
 prepkey(unsigned char *pw, int pwlen)
 {
-	int ret, nrounds = 5;
+	int nrounds = 1000;
 
-	ret = EVP_BytesToKey(EVP_aes_256_gcm(), EVP_sha512(),
-	                     NULL, pw, pwlen, nrounds, aeskey, NULL);
-	if (ret != 32)
-		logerr("wrong key size %d", ret);
+	if (PKCS5_PBKDF2_HMAC_SHA1(pw, pwlen, NULL, 0, nrounds, 32, aeskey) != 1)
+		logerr("PKCS5_PBKDF2_HMAC_SHA1 failed");
 	return 0;
 }