[openssl-commits] [openssl] OpenSSL_1_0_2-stable update

[Matt Caswell]

The branch OpenSSL_1_0_2-stable has been updated
       via  77857ddcca41e1ad34725715fe7b32adc4de7930 (commit)
      from  cbffd2d9ca91dabb1cdfb181311f2a8458b4a8e8 (commit)


- Log -----------------------------------------------------------------
commit 77857ddcca41e1ad34725715fe7b32adc4de7930
Author: Matt Caswell <matt at openssl.org>
Date:   Fri Jul 1 11:58:05 2016 +0100

    Avoid an overflow in constructing the ServerKeyExchange message
    
    We calculate the size required for the ServerKeyExchange message and then
    call BUF_MEM_grow_clean() on the buffer. However we fail to take account of
    2 bytes required for the signature algorithm and 2 bytes for the signature
    length, i.e. we could overflow by 4 bytes. In reality this won't happen
    because the buffer is pre-allocated to a large size that means it should be
    big enough anyway.
    
    Addresses an OCAP Audit issue.
    
    Reviewed-by: Rich Salz <rsalz at openssl.org>

-----------------------------------------------------------------------

Summary of changes:
 ssl/s3_srvr.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c
index 0c43c49..299f85b 100644
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -1872,6 +1872,11 @@ int ssl3_send_server_key_exchange(SSL *s)
                 goto f_err;
             }
             kn = EVP_PKEY_size(pkey);
+            /* Allow space for signature algorithm */
+            if (SSL_USE_SIGALGS(s))
+                kn += 2;
+            /* Allow space for signature length */
+            kn += 2;
         } else {
             pkey = NULL;
             kn = 0;