Allow the configuration of padding when using CID extension

This commit is contained in:
Hanno Becker 2019-05-08 17:37:58 +01:00
parent 9bf10ea25d
commit 550e1662c7
5 changed files with 32 additions and 4 deletions

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@ -3200,6 +3200,22 @@
*/
//#define MBEDTLS_SSL_CID_OUT_LEN_MAX 32
/** \def MBEDTLS_SSL_CID_PADDING_GRANULARITY
*
* This option controls the use of record plaintext padding
* when using the Connection ID extension in DTLS 1.2.
*
* The padding will always be chosen so that the length of the
* padded plaintext is a multiple of the value of this option.
*
* Note: A value of \c 1 means that no padding will be used
* for outgoing records.
*
* The value MUST be a power of 2.
*
*/
//#define MBEDTLS_SSL_CID_PADDING_GRANULARITY 16
/** \def MBEDTLS_SSL_OUT_CONTENT_LEN
*
* Maximum length (in bytes) of outgoing plaintext fragments.

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@ -266,6 +266,10 @@
#define MBEDTLS_SSL_CID_OUT_LEN_MAX 32
#endif
#if !defined(MBEDTLS_SSL_CID_PADDING_GRANULARITY)
#define MBEDTLS_SSL_CID_PADDING_GRANULARITY 16
#endif
/* \} name SECTION: Module settings */
/*

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@ -167,9 +167,7 @@
#endif
#if defined(MBEDTLS_SSL_CID)
#define MBEDTLS_SSL_MAX_CID_EXPANSION 16 /* Currently, we pad records
* to lengths which are multiples
* of 16 Bytes. */
#define MBEDTLS_SSL_MAX_CID_EXPANSION MBEDTLS_SSL_CID_PADDING_GRANULARITY
#else
#define MBEDTLS_SSL_MAX_CID_EXPANSION 0
#endif

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@ -1591,7 +1591,9 @@ static int ssl_cid_build_inner_plaintext( unsigned char *content,
uint8_t rec_type )
{
size_t len = *content_size;
size_t pad = ~len & 0xF; /* Pad to a multiple of 16 */
/* MBEDTLS_SSL_CID_PADDING_GRANULARITY must be a power of 2. */
size_t pad = ~len & ( MBEDTLS_SSL_CID_PADDING_GRANULARITY - 1 );
/* Write real content type */
if( remaining == 0 )

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@ -2450,6 +2450,14 @@ int query_config( const char *config )
}
#endif /* MBEDTLS_SSL_CID_OUT_LEN_MAX */
#if defined(MBEDTLS_SSL_CID_PADDING_GRANULARITY)
if( strcmp( "MBEDTLS_SSL_CID_PADDING_GRANULARITY", config ) == 0 )
{
MACRO_EXPANSION_TO_STR( MBEDTLS_SSL_CID_PADDING_GRANULARITY );
return( 0 );
}
#endif /* MBEDTLS_SSL_CID_PADDING_GRANULARITY */
#if defined(MBEDTLS_SSL_OUT_CONTENT_LEN)
if( strcmp( "MBEDTLS_SSL_OUT_CONTENT_LEN", config ) == 0 )
{