Make cipher_set_padding() actually work

(Only one padding mode recognized yet.)
This commit is contained in:
Manuel Pégourié-Gonnard 2013-07-25 12:31:10 +02:00 committed by Paul Bakker
parent d5fdcaf9e5
commit ac56a1aec4
2 changed files with 32 additions and 16 deletions

View File

@ -202,6 +202,10 @@ typedef struct {
/** Operation that the context's key has been initialised for */
operation_t operation;
/** Padding functions to use, if relevant for cipher mode */
void (*add_padding)( unsigned char *output, size_t olen, size_t data_len );
int (*get_padding)( unsigned char *input, size_t ilen, size_t *data_len );
/** Buffer for data that hasn't been encrypted yet */
unsigned char unprocessed_data[POLARSSL_MAX_IV_LENGTH];

View File

@ -323,6 +323,11 @@ int cipher_init_ctx( cipher_context_t *ctx, const cipher_info_t *cipher_info )
ctx->cipher_info = cipher_info;
/*
* Ignore possible errors caused by a cipher mode that doesn't use padding
*/
(void) cipher_set_padding_mode( ctx, POLARSSL_PADDING_PKCS7 );
return 0;
}
@ -368,18 +373,6 @@ int cipher_setkey( cipher_context_t *ctx, const unsigned char *key,
return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA;
}
int cipher_set_padding_mode( cipher_context_t *ctx, cipher_padding_t mode )
{
if( NULL == ctx ||
POLARSSL_MODE_CBC != ctx->cipher_info->mode ||
POLARSSL_PADDING_PKCS7 != mode )
{
return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA;
}
return 0;
}
int cipher_reset( cipher_context_t *ctx, const unsigned char *iv )
{
if( NULL == ctx || NULL == ctx->cipher_info || NULL == iv )
@ -543,8 +536,8 @@ static void add_pkcs_padding( unsigned char *output, size_t output_len,
output[data_len + i] = (unsigned char) padding_len;
}
static int get_pkcs_padding( unsigned char *input, unsigned int input_len,
size_t *data_len)
static int get_pkcs_padding( unsigned char *input, size_t input_len,
size_t *data_len )
{
unsigned int i, padding_len = 0;
@ -585,7 +578,7 @@ int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen)
{
if( POLARSSL_ENCRYPT == ctx->operation )
{
add_pkcs_padding( ctx->unprocessed_data, cipher_get_iv_size( ctx ),
ctx->add_padding( ctx->unprocessed_data, cipher_get_iv_size( ctx ),
ctx->unprocessed_len );
}
else if ( cipher_get_block_size( ctx ) != ctx->unprocessed_len )
@ -604,7 +597,8 @@ int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen)
/* Set output size for decryption */
if( POLARSSL_DECRYPT == ctx->operation )
return get_pkcs_padding( output, cipher_get_block_size( ctx ), olen );
return ctx->get_padding( output, cipher_get_block_size( ctx ),
olen );
/* Set output size for encryption */
*olen = cipher_get_block_size( ctx );
@ -614,6 +608,24 @@ int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen)
return POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE;
}
int cipher_set_padding_mode( cipher_context_t *ctx, cipher_padding_t mode )
{
if( NULL == ctx ||
POLARSSL_MODE_CBC != ctx->cipher_info->mode )
{
return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA;
}
if( POLARSSL_PADDING_PKCS7 == mode )
{
ctx->add_padding = add_pkcs_padding;
ctx->get_padding = get_pkcs_padding;
return 0;
}
return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA;
}
#if defined(POLARSSL_SELF_TEST)
#include <stdio.h>