pay attention to blocksize before attempting decryption

[openssl.git] / ssl / s3_enc.c

diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c
index 8cd36a395c8b5fe4f89672c1801a04f3dc2f4b86..d1c1946e549e78445a043a13fa4192691ce68d6a 100644 (file)
--- a/ssl/s3_enc.c
+++ b/ssl/s3_enc.c
@@ -373,7 +373,6 @@ int ssl3_enc(SSL *s, int send)
 
                /* COMPRESS */
 
-               /* This should be using (bs-1) and bs instead of 7 and 8 */
                if ((bs != 1) && send)
                        {
                        i=bs-((int)l%bs);
@@ -383,12 +382,24 @@ int ssl3_enc(SSL *s, int send)
                        rec->length+=i;
                        rec->input[l-1]=(i-1);
                        }
-
+               
+               if (!send)
+                       {
+                       if (l == 0 || l%bs != 0)
+                               {
+                               SSLerr(SSL_F_SSL3_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
+                               ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPT_ERROR);
+                               return(0);
+                               }
+                       }
+               
                EVP_Cipher(ds,rec->data,rec->input,l);
 
                if ((bs != 1) && !send)
                        {
                        i=rec->data[l-1]+1;
+                       /* SSL 3.0 bounds the number of padding bytes by the block size;
+                        * padding bytes (except that last) are arbitrary */
                        if (i > bs)
                                {
                                SSLerr(SSL_F_SSL3_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);