diff --git a/ChangeLog b/ChangeLog index 5884e498d..5afc2a1dc 100644 --- a/ChangeLog +++ b/ChangeLog @@ -3,6 +3,8 @@ PolarSSL ChangeLog = Branch 1.1 Changes * Allow enabling of dummy error_strerror() to support some use-cases + * Debug messages about padding errors during SSL message decryption are + disabled by default and can be enabled with POLARSSL_SSL_DEBUG_ALL Security * Removed timing differences during SSL message decryption in diff --git a/include/polarssl/config.h b/include/polarssl/config.h index 110e3b4b5..e597edf9a 100644 --- a/include/polarssl/config.h +++ b/include/polarssl/config.h @@ -216,6 +216,22 @@ */ #define POLARSSL_SELF_TEST +/** + * \def POLARSSL_SSL_DEBUG_ALL + * + * Enable the debug messages in SSL module for all issues. + * Debug messages have been disabled in some places to prevent timing + * attacks due to (unbalanced) debugging function calls. + * + * If you need all error reporting you should enable this during debugging, + * but remove this for production servers that should log as well. + * + * Uncomment this macro to report all debug messages on errors introducing + * a timing side-channel. + * +#define POLARSSL_SSL_DEBUG_ALL + */ + /** * \def POLARSSL_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION * diff --git a/library/ssl_tls.c b/library/ssl_tls.c index 95e912f0d..2c618a7ff 100644 --- a/library/ssl_tls.c +++ b/library/ssl_tls.c @@ -769,9 +769,10 @@ static int ssl_decrypt_buf( ssl_context *ssl ) if( ssl->in_msglen < ssl->maclen + padlen ) { +#if defined(POLARSSL_SSL_DEBUG_ALL) SSL_DEBUG_MSG( 1, ( "msglen (%d) < maclen (%d) + padlen (%d)", ssl->in_msglen, ssl->maclen, padlen ) ); - +#endif padlen = 0; fake_padlen = 256; correct = 0; @@ -781,9 +782,11 @@ static int ssl_decrypt_buf( ssl_context *ssl ) { if( padlen > ssl->ivlen ) { +#if defined(POLARSSL_SSL_DEBUG_ALL) SSL_DEBUG_MSG( 1, ( "bad padding length: is %d, " "should be no more than %d", padlen, ssl->ivlen ) ); +#endif correct = 0; } } @@ -809,8 +812,10 @@ static int ssl_decrypt_buf( ssl_context *ssl ) else minlen = 1; } +#if defined(POLARSSL_SSL_DEBUG_ALL) if( padlen > 0 && correct == 0) SSL_DEBUG_MSG( 1, ( "bad padding byte detected" ) ); +#endif } }