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Change cipher prototypes for GCM

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This commit is contained in:
Manuel Pégourié-Gonnard 2013-08-31 17:31:03 +02:00
parent 20d6a17af9
commit 9241be7ac5
9 changed files with 94 additions and 39 deletions
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22
include/polarssl/cipher.h
View File

@ -320,7 +320,7 @@ static inline cipher_mode_t cipher_get_cipher_mode( const cipher_context_t *ctx
* \param ctx cipher's context. Must have been initialised. * \param ctx cipher's context. Must have been initialised.
* *
* \return size of the cipher's IV, or 0 if ctx has not been * \return size of the cipher's IV, or 0 if ctx has not been
* initialised. * initialised or accepts IV of various sizes.
*/ */
static inline int cipher_get_iv_size( const cipher_context_t *ctx ) static inline int cipher_get_iv_size( const cipher_context_t *ctx )
{ {
@ -432,11 +432,18 @@ int cipher_set_padding_mode( cipher_context_t *ctx, cipher_padding_t mode );
* *
* \param ctx generic cipher context * \param ctx generic cipher context
* \param iv IV to use or NONCE_COUNTER in the case of a CTR-mode cipher * \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.
* *
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA * \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA
* if parameter verification fails. * if parameter verification fails.
*/ */
int cipher_reset( cipher_context_t *ctx, const unsigned char *iv ); int cipher_reset( cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len );
/** /**
* \brief Generic cipher update function. Encrypts/decrypts * \brief Generic cipher update function. Encrypts/decrypts
@ -471,8 +478,13 @@ int cipher_update( cipher_context_t *ctx, const unsigned char *input, size_t ile
* the last block, and written to the output buffer. * the last block, and written to the output buffer.
* *
* \param ctx Generic cipher context * \param ctx Generic cipher context
* \param output buffer to write data to. Needs block_size data available. * \param output buffer to write data to. Needs block_size available.
* \param olen length of the data written to the output buffer. * \param olen length of the data written to the output buffer.
* \param tag Ignore by non-AEAD ciphers. For AEAD ciphers:
* - on encryption: buffer to write the tag;
* - on decryption: tag to verify.
* May be NULL if tag_len is zero.
* \param tag_len Length of the tag to write/check for AEAD ciphers.
* *
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if * \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
* parameter verification fails, * parameter verification fails,
@ -481,7 +493,9 @@ int cipher_update( cipher_context_t *ctx, const unsigned char *input, size_t ile
* POLARSSL_ERR_CIPHER_INVALID_PADDING on invalid padding * POLARSSL_ERR_CIPHER_INVALID_PADDING on invalid padding
* while decrypting or a cipher specific error code. * while decrypting or a cipher specific error code.
*/ */
int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen); int cipher_finish( cipher_context_t *ctx,
unsigned char *output, size_t *olen,
unsigned char *tag, size_t tag_len );
/** /**
* \brief Checkup routine * \brief Checkup routine

8
include/polarssl/gcm.h
View File

@ -146,7 +146,7 @@ int gcm_auth_decrypt( gcm_context *ctx,
* \param mode GCM_ENCRYPT or GCM_DECRYPT * \param mode GCM_ENCRYPT or GCM_DECRYPT
* \param iv initialization vector * \param iv initialization vector
* \param iv_len length of IV * \param iv_len length of IV
* \param add additional data * \param add additional data (or NULL if length is 0)
* \param add_len length of additional data * \param add_len length of additional data
* *
* \return 0 if successful * \return 0 if successful
@ -182,14 +182,14 @@ int gcm_update( gcm_context *ctx,
/** /**
* \brief Generic GCM finalisation function. Wraps up the GCM stream * \brief Generic GCM finalisation function. Wraps up the GCM stream
* and generated the tag. The tag can have a maximum length of * and generates the tag. The tag can have a maximum length of
* 16 bytes. * 16 bytes.
* *
* \param ctx GCM context * \param ctx GCM context
* \param tag buffer for holding the tag * \param tag buffer for holding the tag (may be NULL if tag_len is 0)
* \param tag_len length of the tag to generate * \param tag_len length of the tag to generate
* *
* \return 0 if successful or POLARSSL_ERR_GCM_BAD_INPUT * \return 0 if successful or POLARSSL_ERR_GCM_BAD_INPUT
*/ */
int gcm_finish( gcm_context *ctx, int gcm_finish( gcm_context *ctx,
unsigned char *tag, unsigned char *tag,

41
library/cipher.c
View File

@ -396,7 +396,9 @@ int cipher_setkey( cipher_context_t *ctx, const unsigned char *key,
return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA;
} }
int cipher_reset( cipher_context_t *ctx, const unsigned char *iv ) int cipher_reset( cipher_context_t *ctx,
const unsigned char *iv, size_t iv_len,
const unsigned char *ad, size_t ad_len )
{ {
if( NULL == ctx || NULL == ctx->cipher_info || NULL == iv ) if( NULL == ctx || NULL == ctx->cipher_info || NULL == iv )
return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA; return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA;
@ -406,11 +408,13 @@ int cipher_reset( cipher_context_t *ctx, const unsigned char *iv )
#if defined(POLARSSL_GCM_C) #if defined(POLARSSL_GCM_C)
if( POLARSSL_MODE_GCM == ctx->cipher_info->mode ) if( POLARSSL_MODE_GCM == ctx->cipher_info->mode )
{ {
// TODO: allow other IV length
// TODO: allow additional data
return gcm_starts( ctx->cipher_ctx, ctx->operation, return gcm_starts( ctx->cipher_ctx, ctx->operation,
iv, 12, (unsigned char *) "", 0 ); iv, iv_len, ad, ad_len );
} }
#else
((void) ad);
((void) ad_len);
((void) iv_len);
#endif #endif
memcpy( ctx->iv, iv, cipher_get_iv_size( ctx ) ); memcpy( ctx->iv, iv, cipher_get_iv_size( ctx ) );
@ -742,7 +746,9 @@ static int get_no_padding( unsigned char *input, size_t input_len,
return 0; return 0;
} }
int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen) int cipher_finish( cipher_context_t *ctx,
unsigned char *output, size_t *olen,
unsigned char *tag, size_t tag_len )
{ {
int ret = 0; int ret = 0;
@ -761,8 +767,9 @@ int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen)
#if defined(POLARSSL_GCM_C) #if defined(POLARSSL_GCM_C)
if( POLARSSL_MODE_GCM == ctx->cipher_info->mode ) if( POLARSSL_MODE_GCM == ctx->cipher_info->mode )
{ {
size_t tag_len = 0; // TODO unsigned char check_tag[16];
unsigned char tag[16]; size_t i;
int diff;
if( 0 != ( ret = gcm_update( ctx->cipher_ctx, if( 0 != ( ret = gcm_update( ctx->cipher_ctx,
ctx->unprocessed_len, ctx->unprocessed_data, ctx->unprocessed_len, ctx->unprocessed_data,
@ -773,11 +780,29 @@ int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen)
*olen += ctx->unprocessed_len; *olen += ctx->unprocessed_len;
if( 0 != ( ret = gcm_finish( ctx->cipher_ctx, tag, tag_len ) ) ) if( 0 != ( ret = gcm_finish( ctx->cipher_ctx, check_tag, tag_len ) ) )
return( ret ); return( ret );
/* On encryption, write the tag */
if( POLARSSL_ENCRYPT == ctx->operation )
{
if( tag_len != 0 )
memcpy( tag, check_tag, tag_len );
return( 0 );
}
/* On decryption, check the tag (in "constant-time") */
for( diff = 0, i = 0; i < tag_len; i++ )
diff |= tag[i] ^ check_tag[i];
if( diff != 0 )
return( POLARSSL_ERR_GCM_AUTH_FAILED );
return( 0 ); return( 0 );
} }
#else
((void) tag);
((void) tag_len);
#endif #endif
if( POLARSSL_MODE_CBC == ctx->cipher_info->mode ) if( POLARSSL_MODE_CBC == ctx->cipher_info->mode )

4
library/cipher_wrap.c
View File

@ -271,7 +271,7 @@ const cipher_info_t aes_128_gcm_info = {
POLARSSL_MODE_GCM, POLARSSL_MODE_GCM,
128, 128,
"AES-128-GCM", "AES-128-GCM",
16, 0,
16, 16,
&gcm_aes_info &gcm_aes_info
}; };
@ -281,7 +281,7 @@ const cipher_info_t aes_256_gcm_info = {
POLARSSL_MODE_GCM, POLARSSL_MODE_GCM,
256, 256,
"AES-256-GCM", "AES-256-GCM",
16, 0,
16, 16,
&gcm_aes_info &gcm_aes_info
}; };

3
library/gcm.c
View File

@ -296,7 +296,8 @@ int gcm_finish( gcm_context *ctx,
if( tag_len > 16 ) if( tag_len > 16 )
return( POLARSSL_ERR_GCM_BAD_INPUT ); return( POLARSSL_ERR_GCM_BAD_INPUT );
memcpy( tag, ctx->base_ectr, tag_len ); if( tag_len != 0 )
memcpy( tag, ctx->base_ectr, tag_len );
if( orig_len || orig_add_len ) if( orig_len || orig_add_len )
{ {

7
library/pkcs12.c
View File

@ -184,7 +184,7 @@ int pkcs12_pbe( asn1_buf *pbe_params, int mode,
if( ( ret = cipher_setkey( &cipher_ctx, key, keylen, mode ) ) != 0 ) if( ( ret = cipher_setkey( &cipher_ctx, key, keylen, mode ) ) != 0 )
goto exit; goto exit;
if( ( ret = cipher_reset( &cipher_ctx, iv ) ) != 0 ) if( ( ret = cipher_reset( &cipher_ctx, iv, 0, NULL, 0 ) ) != 0 )
goto exit; goto exit;
if( ( ret = cipher_update( &cipher_ctx, data, len, if( ( ret = cipher_update( &cipher_ctx, data, len,
@ -193,8 +193,11 @@ int pkcs12_pbe( asn1_buf *pbe_params, int mode,
goto exit; goto exit;
} }
if( ( ret = cipher_finish( &cipher_ctx, output + olen, &olen ) ) != 0 ) if( ( ret = cipher_finish( &cipher_ctx, output + olen, &olen, NULL, 0 ) )
!= 0 )
{
ret = POLARSSL_ERR_PKCS12_PASSWORD_MISMATCH; ret = POLARSSL_ERR_PKCS12_PASSWORD_MISMATCH;
}
exit: exit:
cipher_free_ctx( &cipher_ctx ); cipher_free_ctx( &cipher_ctx );

7
library/pkcs5.c
View File

@ -187,7 +187,7 @@ int pkcs5_pbes2( asn1_buf *pbe_params, int mode,
if( ( ret = cipher_setkey( &cipher_ctx, key, keylen, mode ) ) != 0 ) if( ( ret = cipher_setkey( &cipher_ctx, key, keylen, mode ) ) != 0 )
goto exit; goto exit;
if( ( ret = cipher_reset( &cipher_ctx, iv ) ) != 0 ) if( ( ret = cipher_reset( &cipher_ctx, iv, 0, NULL, 0 ) ) != 0 )
goto exit; goto exit;
if( ( ret = cipher_update( &cipher_ctx, data, datalen, if( ( ret = cipher_update( &cipher_ctx, data, datalen,
@ -196,8 +196,11 @@ int pkcs5_pbes2( asn1_buf *pbe_params, int mode,
goto exit; goto exit;
} }
if( ( ret = cipher_finish( &cipher_ctx, output + olen, &olen ) ) != 0 ) if( ( ret = cipher_finish( &cipher_ctx, output + olen, &olen, NULL, 0 ) )
!= 0 )
{
ret = POLARSSL_ERR_PKCS5_PASSWORD_MISMATCH; ret = POLARSSL_ERR_PKCS5_PASSWORD_MISMATCH;
}
exit: exit:
md_free_ctx( &md_ctx ); md_free_ctx( &md_ctx );

8
programs/aes/crypt_and_hash.c
View File

@ -306,7 +306,7 @@ int main( int argc, char *argv[] )
fprintf( stderr, "cipher_setkey() returned error\n"); fprintf( stderr, "cipher_setkey() returned error\n");
goto exit; goto exit;
} }
if( cipher_reset( &cipher_ctx, IV ) != 0 ) if( cipher_reset( &cipher_ctx, IV, 16, NULL, 0 ) != 0 )
{ {
fprintf( stderr, "cipher_reset() returned error\n"); fprintf( stderr, "cipher_reset() returned error\n");
goto exit; goto exit;
@ -338,7 +338,7 @@ int main( int argc, char *argv[] )
} }
} }
if( cipher_finish( &cipher_ctx, output, &olen ) != 0 ) if( cipher_finish( &cipher_ctx, output, &olen, NULL, 0 ) != 0 )
{ {
fprintf( stderr, "cipher_finish() returned error\n" ); fprintf( stderr, "cipher_finish() returned error\n" );
goto exit; goto exit;
@ -424,7 +424,7 @@ int main( int argc, char *argv[] )
cipher_setkey( &cipher_ctx, digest, cipher_info->key_length, cipher_setkey( &cipher_ctx, digest, cipher_info->key_length,
POLARSSL_DECRYPT ); POLARSSL_DECRYPT );
cipher_reset( &cipher_ctx, IV); cipher_reset( &cipher_ctx, IV, 16, NULL, 0 );
md_hmac_starts( &md_ctx, digest, 32 ); md_hmac_starts( &md_ctx, digest, 32 );
@ -455,7 +455,7 @@ int main( int argc, char *argv[] )
/* /*
* Write the final block of data * Write the final block of data
*/ */
cipher_finish( &cipher_ctx, output, &olen ); cipher_finish( &cipher_ctx, output, &olen, NULL, 0 );
if( fwrite( output, 1, olen, fout ) != olen ) if( fwrite( output, 1, olen, fout ) != olen )
{ {

33
tests/suites/test_suite_cipher.function
View File

@ -14,6 +14,8 @@ void enc_dec_buf( int cipher_id, char *cipher_string, int key_len,
size_t length = length_val; size_t length = length_val;
unsigned char key[32]; unsigned char key[32];
unsigned char iv[16]; unsigned char iv[16];
unsigned char ad[13];
unsigned char tag[16];
const cipher_info_t *cipher_info; const cipher_info_t *cipher_info;
cipher_context_t ctx_dec; cipher_context_t ctx_dec;
@ -35,6 +37,8 @@ void enc_dec_buf( int cipher_id, char *cipher_string, int key_len,
memset( inbuf, 5, 64 ); memset( inbuf, 5, 64 );
memset( encbuf, 0, 64 ); memset( encbuf, 0, 64 );
memset( decbuf, 0, 64 ); memset( decbuf, 0, 64 );
memset( tag, 0, 16 );
memset( ad, 0x2a, 13 );
/* Check and get info structures */ /* Check and get info structures */
cipher_info = cipher_info_from_type( cipher_id ); cipher_info = cipher_info_from_type( cipher_id );
@ -54,8 +58,8 @@ 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_set_padding_mode( &ctx_enc, pad_mode ) );
} }
TEST_ASSERT( 0 == cipher_reset( &ctx_dec, iv ) ); TEST_ASSERT( 0 == cipher_reset( &ctx_dec, iv, 16, ad, 13 ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_enc, iv ) ); TEST_ASSERT( 0 == cipher_reset( &ctx_enc, iv, 16, ad, 13 ) );
/* encode length number of bytes from inbuf */ /* encode length number of bytes from inbuf */
TEST_ASSERT( 0 == cipher_update( &ctx_enc, inbuf, length, encbuf, &outlen ) ); TEST_ASSERT( 0 == cipher_update( &ctx_enc, inbuf, length, encbuf, &outlen ) );
@ -66,7 +70,8 @@ void enc_dec_buf( int cipher_id, char *cipher_string, int key_len,
total_len < length && total_len < length &&
total_len + cipher_get_block_size( &ctx_enc ) > length ) ); total_len + cipher_get_block_size( &ctx_enc ) > length ) );
TEST_ASSERT( 0 == cipher_finish( &ctx_enc, encbuf + outlen, &outlen ) ); TEST_ASSERT( 0 == cipher_finish( &ctx_enc, encbuf + outlen, &outlen,
tag, 16 ) );
total_len += outlen; total_len += outlen;
TEST_ASSERT( total_len == length || TEST_ASSERT( total_len == length ||
@ -83,7 +88,8 @@ void enc_dec_buf( int cipher_id, char *cipher_string, int key_len,
total_len < length && total_len < length &&
total_len + cipher_get_block_size( &ctx_dec ) >= length ) ); total_len + cipher_get_block_size( &ctx_dec ) >= length ) );
TEST_ASSERT( 0 == cipher_finish( &ctx_dec, decbuf + outlen, &outlen ) ); TEST_ASSERT( 0 == cipher_finish( &ctx_dec, decbuf + outlen, &outlen,
tag, 16 ) );
total_len += outlen; total_len += outlen;
TEST_ASSERT( total_len == length ); TEST_ASSERT( total_len == length );
@ -127,11 +133,11 @@ 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_init_ctx( &ctx, cipher_info ) );
TEST_ASSERT( 0 == cipher_setkey( &ctx, key, key_len, POLARSSL_ENCRYPT ) ); 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_set_padding_mode( &ctx, pad_mode ) );
TEST_ASSERT( 0 == cipher_reset( &ctx, iv ) ); TEST_ASSERT( 0 == cipher_reset( &ctx, iv, 16, NULL, 0 ) );
/* encode length number of bytes from inbuf */ /* encode length number of bytes from inbuf */
TEST_ASSERT( 0 == cipher_update( &ctx, inbuf, length, encbuf, &outlen ) ); TEST_ASSERT( 0 == cipher_update( &ctx, inbuf, length, encbuf, &outlen ) );
TEST_ASSERT( ret == cipher_finish( &ctx, encbuf + outlen, &outlen ) ); TEST_ASSERT( ret == cipher_finish( &ctx, encbuf + outlen, &outlen, NULL, 0 ) );
/* done */ /* done */
TEST_ASSERT( 0 == cipher_free_ctx( &ctx ) ); TEST_ASSERT( 0 == cipher_free_ctx( &ctx ) );
@ -168,12 +174,13 @@ void dec_empty_buf()
TEST_ASSERT( 0 == cipher_setkey( &ctx_dec, key, 128, POLARSSL_DECRYPT ) ); TEST_ASSERT( 0 == cipher_setkey( &ctx_dec, key, 128, POLARSSL_DECRYPT ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_dec, iv ) ); TEST_ASSERT( 0 == cipher_reset( &ctx_dec, iv, 16, NULL, 0 ) );
/* decode 0-byte string */ /* decode 0-byte string */
TEST_ASSERT( 0 == cipher_update( &ctx_dec, encbuf, 0, decbuf, &outlen ) ); TEST_ASSERT( 0 == cipher_update( &ctx_dec, encbuf, 0, decbuf, &outlen ) );
TEST_ASSERT( 0 == outlen ); TEST_ASSERT( 0 == outlen );
TEST_ASSERT( POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED == cipher_finish( &ctx_dec, decbuf + outlen, &outlen ) ); TEST_ASSERT( POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED == cipher_finish(
&ctx_dec, decbuf + outlen, &outlen, NULL, 0 ) );
TEST_ASSERT( 0 == outlen ); TEST_ASSERT( 0 == outlen );
TEST_ASSERT( 0 == cipher_free_ctx( &ctx_dec ) ); TEST_ASSERT( 0 == cipher_free_ctx( &ctx_dec ) );
@ -221,8 +228,8 @@ 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_dec, key, key_len, POLARSSL_DECRYPT ) );
TEST_ASSERT( 0 == cipher_setkey( &ctx_enc, key, key_len, POLARSSL_ENCRYPT ) ); TEST_ASSERT( 0 == cipher_setkey( &ctx_enc, key, key_len, POLARSSL_ENCRYPT ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_dec, iv ) ); TEST_ASSERT( 0 == cipher_reset( &ctx_dec, iv, 16, NULL, 0 ) );
TEST_ASSERT( 0 == cipher_reset( &ctx_enc, iv ) ); TEST_ASSERT( 0 == cipher_reset( &ctx_enc, iv, 16, NULL, 0 ) );
/* encode length number of bytes from inbuf */ /* encode length number of bytes from inbuf */
TEST_ASSERT( 0 == cipher_update( &ctx_enc, inbuf, first_length, encbuf, &outlen ) ); TEST_ASSERT( 0 == cipher_update( &ctx_enc, inbuf, first_length, encbuf, &outlen ) );
@ -234,7 +241,8 @@ void enc_dec_buf_multipart( int cipher_id, int key_len, int first_length_val,
totaloutlen < length && totaloutlen < length &&
totaloutlen + cipher_get_block_size( &ctx_enc ) > length ) ); totaloutlen + cipher_get_block_size( &ctx_enc ) > length ) );
TEST_ASSERT( 0 == cipher_finish( &ctx_enc, encbuf + totaloutlen, &outlen ) ); TEST_ASSERT( 0 == cipher_finish( &ctx_enc, encbuf + totaloutlen, &outlen,
NULL, 0 ) );
totaloutlen += outlen; totaloutlen += outlen;
TEST_ASSERT( totaloutlen == length || TEST_ASSERT( totaloutlen == length ||
( totaloutlen % cipher_get_block_size( &ctx_enc ) == 0 && ( totaloutlen % cipher_get_block_size( &ctx_enc ) == 0 &&
@ -250,7 +258,8 @@ void enc_dec_buf_multipart( int cipher_id, int key_len, int first_length_val,
totaloutlen < length && totaloutlen < length &&
totaloutlen + cipher_get_block_size( &ctx_dec ) >= length ) ); totaloutlen + cipher_get_block_size( &ctx_dec ) >= length ) );
TEST_ASSERT( 0 == cipher_finish( &ctx_dec, decbuf + outlen, &outlen ) ); TEST_ASSERT( 0 == cipher_finish( &ctx_dec, decbuf + outlen, &outlen,
NULL, 0 ) );
totaloutlen += outlen; totaloutlen += outlen;
TEST_ASSERT( totaloutlen == length ); TEST_ASSERT( totaloutlen == length );