Split cipher_set_iv() out of cipher_reset()

This commit is contained in:
Manuel Pégourié-Gonnard 2013-09-03 13:04:44 +02:00
parent 9241be7ac5
commit 9c853b910c
6 changed files with 79 additions and 26 deletions

View File

@ -185,7 +185,8 @@ typedef struct {
/** Name of the cipher */
const char * name;
/** IV size, in bytes */
/** IV/NONCE size, in bytes, for ciphers with fixed-length IVs), or
* 0 for ciphers with variable-length IVs or not using IVs */
unsigned int iv_size;
/** block size, in bytes */
@ -222,6 +223,9 @@ typedef struct {
/** Current IV or NONCE_COUNTER for CTR-mode */
unsigned char iv[POLARSSL_MAX_IV_LENGTH];
/** IV size in bytes (for ciphers with variable-length IVs) */
size_t iv_size;
/** Cipher-specific context */
void *cipher_ctx;
} cipher_context_t;
@ -315,18 +319,22 @@ static inline cipher_mode_t cipher_get_cipher_mode( const cipher_context_t *ctx
}
/**
* \brief Returns the size of the cipher's IV.
* \brief Returns the size of the cipher's IV/NONCE in bytes.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return size of the cipher's IV, or 0 if ctx has not been
* initialised or accepts IV of various sizes.
* \return If IV has not been set yet: desired size for ciphers
* with fixed-size IVs, 0 for other ciphers.
* If IV has already been set: actual size.
*/
static inline int cipher_get_iv_size( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return 0;
if( ctx->iv_size != 0 )
return ctx->iv_size;
return ctx->cipher_info->iv_size;
}
@ -427,13 +435,25 @@ int cipher_setkey( cipher_context_t *ctx, const unsigned char *key, int key_leng
*/
int cipher_set_padding_mode( cipher_context_t *ctx, cipher_padding_t mode );
/**
* \brief Set the initialization vector (IV) or nonce
*
* \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers)
* \param iv_len IV length for ciphers with variable-size IV,
* Discarded by ciphers with fixed-size IV.
*
* \returns O on success, or POLARSSL_ERR_CIPHER_BAD_INPUT_DATA
*
* \note Some ciphers don't use IVs nor NONCE. For these
* ciphers, this function has no effect.
*/
int cipher_set_iv( cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len );
/**
* \brief Reset the given context, setting the IV to iv
*
* \param ctx generic cipher context
* \param iv IV to use or NONCE_COUNTER in the case of a CTR-mode cipher
* \param iv_len IV length for ciphers with variable-size IV,
* Discared by ciphers with fixed-size IV.
* \param ad Additional data for AEAD ciphers, or discarded.
* May be NULL only if ad_len is 0.
* \param ad_len Length of ad for AEAD ciphers, or discarded.
@ -442,7 +462,6 @@ int cipher_set_padding_mode( cipher_context_t *ctx, cipher_padding_t mode );
* if parameter verification fails.
*/
int cipher_reset( cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len );
/**

View File

@ -396,29 +396,42 @@ int cipher_setkey( cipher_context_t *ctx, const unsigned char *key,
return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA;
}
int cipher_reset( cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len )
int cipher_set_iv( cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len )
{
size_t fixed_iv_size;
if( NULL == ctx || NULL == ctx->cipher_info || NULL == iv )
return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA;
fixed_iv_size = cipher_get_iv_size( ctx );
/* 0 means variable size (or no IV): use given len */
if( fixed_iv_size == 0 )
fixed_iv_size = iv_len;
memcpy( ctx->iv, iv, fixed_iv_size );
ctx->iv_size = fixed_iv_size;
return 0;
}
int cipher_reset( cipher_context_t *ctx,
const unsigned char *ad, size_t ad_len )
{
ctx->unprocessed_len = 0;
#if defined(POLARSSL_GCM_C)
if( POLARSSL_MODE_GCM == ctx->cipher_info->mode )
{
return gcm_starts( ctx->cipher_ctx, ctx->operation,
iv, iv_len, ad, ad_len );
ctx->iv, ctx->iv_size, ad, ad_len );
}
#else
((void) ad);
((void) ad_len);
((void) iv_len);
#endif
memcpy( ctx->iv, iv, cipher_get_iv_size( ctx ) );
return 0;
}

View File

@ -184,7 +184,10 @@ int pkcs12_pbe( asn1_buf *pbe_params, int mode,
if( ( ret = cipher_setkey( &cipher_ctx, key, keylen, mode ) ) != 0 )
goto exit;
if( ( ret = cipher_reset( &cipher_ctx, iv, 0, NULL, 0 ) ) != 0 )
if( ( ret = cipher_set_iv( &cipher_ctx, iv, 0 ) ) != 0 )
goto exit;
if( ( ret = cipher_reset( &cipher_ctx, iv, 0 ) ) != 0 )
goto exit;
if( ( ret = cipher_update( &cipher_ctx, data, len,

View File

@ -187,7 +187,10 @@ int pkcs5_pbes2( asn1_buf *pbe_params, int mode,
if( ( ret = cipher_setkey( &cipher_ctx, key, keylen, mode ) ) != 0 )
goto exit;
if( ( ret = cipher_reset( &cipher_ctx, iv, 0, NULL, 0 ) ) != 0 )
if( ( ret = cipher_set_iv( &cipher_ctx, iv, 0 ) ) != 0 )
goto exit;
if( ( ret = cipher_reset( &cipher_ctx, NULL, 0 ) ) != 0 )
goto exit;
if( ( ret = cipher_update( &cipher_ctx, data, datalen,

View File

@ -306,7 +306,12 @@ int main( int argc, char *argv[] )
fprintf( stderr, "cipher_setkey() returned error\n");
goto exit;
}
if( cipher_reset( &cipher_ctx, IV, 16, NULL, 0 ) != 0 )
if( cipher_set_iv( &cipher_ctx, IV, 16 ) != 0 )
{
fprintf( stderr, "cipher_set_iv() returned error\n");
goto exit;
}
if( cipher_reset( &cipher_ctx, NULL, 0 ) != 0 )
{
fprintf( stderr, "cipher_reset() returned error\n");
goto exit;
@ -424,7 +429,8 @@ int main( int argc, char *argv[] )
cipher_setkey( &cipher_ctx, digest, cipher_info->key_length,
POLARSSL_DECRYPT );
cipher_reset( &cipher_ctx, IV, 16, NULL, 0 );
cipher_set_iv( &cipher_ctx, IV, 16 );
cipher_reset( &cipher_ctx, NULL, 0 );
md_hmac_starts( &md_ctx, digest, 32 );

View File

@ -58,8 +58,11 @@ void enc_dec_buf( int cipher_id, char *cipher_string, int key_len,
TEST_ASSERT( 0 == cipher_set_padding_mode( &ctx_enc, pad_mode ) );
}
TEST_ASSERT( 0 == cipher_reset( &ctx_dec, iv, 16, ad, 13 ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_enc, iv, 16, ad, 13 ) );
TEST_ASSERT( 0 == cipher_set_iv( &ctx_dec, iv, 16 ) );
TEST_ASSERT( 0 == cipher_set_iv( &ctx_enc, iv, 16 ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_dec, ad, 13 ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_enc, ad, 13 ) );
/* encode length number of bytes from inbuf */
TEST_ASSERT( 0 == cipher_update( &ctx_enc, inbuf, length, encbuf, &outlen ) );
@ -133,7 +136,8 @@ void enc_fail( int cipher_id, int pad_mode, int key_len,
TEST_ASSERT( 0 == cipher_init_ctx( &ctx, cipher_info ) );
TEST_ASSERT( 0 == cipher_setkey( &ctx, key, key_len, POLARSSL_ENCRYPT ) );
TEST_ASSERT( 0 == cipher_set_padding_mode( &ctx, pad_mode ) );
TEST_ASSERT( 0 == cipher_reset( &ctx, iv, 16, NULL, 0 ) );
TEST_ASSERT( 0 == cipher_set_iv( &ctx, iv, 16 ) );
TEST_ASSERT( 0 == cipher_reset( &ctx, NULL, 0 ) );
/* encode length number of bytes from inbuf */
TEST_ASSERT( 0 == cipher_update( &ctx, inbuf, length, encbuf, &outlen ) );
@ -166,7 +170,7 @@ void dec_empty_buf()
memset( encbuf, 0, 64 );
memset( decbuf, 0, 64 );
/* Initialise enc and dec contexts */
/* Initialise context */
cipher_info = cipher_info_from_type( POLARSSL_CIPHER_AES_128_CBC );
TEST_ASSERT( NULL != cipher_info);
@ -174,7 +178,9 @@ void dec_empty_buf()
TEST_ASSERT( 0 == cipher_setkey( &ctx_dec, key, 128, POLARSSL_DECRYPT ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_dec, iv, 16, NULL, 0 ) );
TEST_ASSERT( 0 == cipher_set_iv( &ctx_dec, iv, 16 ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_dec, NULL, 0 ) );
/* decode 0-byte string */
TEST_ASSERT( 0 == cipher_update( &ctx_dec, encbuf, 0, decbuf, &outlen ) );
@ -228,8 +234,11 @@ void enc_dec_buf_multipart( int cipher_id, int key_len, int first_length_val,
TEST_ASSERT( 0 == cipher_setkey( &ctx_dec, key, key_len, POLARSSL_DECRYPT ) );
TEST_ASSERT( 0 == cipher_setkey( &ctx_enc, key, key_len, POLARSSL_ENCRYPT ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_dec, iv, 16, NULL, 0 ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_enc, iv, 16, NULL, 0 ) );
TEST_ASSERT( 0 == cipher_set_iv( &ctx_dec, iv, 16 ) );
TEST_ASSERT( 0 == cipher_set_iv( &ctx_enc, iv, 16 ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_dec, NULL, 0 ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_enc, NULL, 0 ) );
/* encode length number of bytes from inbuf */
TEST_ASSERT( 0 == cipher_update( &ctx_enc, inbuf, first_length, encbuf, &outlen ) );