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Fix false reject in padding check in ssl_decrypt_buf() for CBC ciphersuites

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In case full SSL frames arrived, they were rejected because an overly
strict padding check.
This commit is contained in:
Paul Bakker
2014-04-25 12:59:03 +02:00
parent fdba46885b
commit 61885c7f7f
2 changed files with 6 additions and 2 deletions
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6
library/ssl_tls.c
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@ -1633,13 +1633,15 @@ static int ssl_decrypt_buf( ssl_context *ssl )
* Padding is guaranteed to be incorrect if:
* 1. padlen >= ssl->in_msglen
*
* 2. padding_idx > SSL_MAX_CONTENT_LEN
* 2. padding_idx >= SSL_MAX_CONTENT_LEN +
* ssl->transform_in->maclen
*
* In both cases we reset padding_idx to a safe value (0) to
* prevent out-of-buffer reads.
*/
correct &= ( ssl->in_msglen >= padlen + 1 );
correct &= ( padding_idx <= SSL_MAX_CONTENT_LEN );
correct &= ( padding_idx < SSL_MAX_CONTENT_LEN +
ssl->transform_in->maclen );
padding_idx *= correct;