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Add ccm_encrypt_and_tag()

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This commit is contained in:
Manuel Pégourié-Gonnard 2014-05-06 12:13:09 +02:00
parent 9fe0d13e8d
commit 637eb3d31d
4 changed files with 457 additions and 2 deletions
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34
include/polarssl/ccm.h
View File

@ -64,6 +64,40 @@ int ccm_init( ccm_context *ctx, cipher_id_t cipher,
*/
void ccm_free( ccm_context *ctx );
/**
* \brief CCM buffer encryption
*
* \todo Document if input/output buffers can be the same
*
* \param ctx CCM context
* \param length length of the input data in bytes
* \param iv nonce (initialization vector)
* \param iv_len length of IV in bytes
* must be 2, 3, 4, 5, 6, 7 or 8
* \param add additional data
* \param add_len length of additional data in bytes
* must be less than 2^16 - 2^8
* \param input buffer holding the input data
* \param output buffer for holding the output data
* must be at least 'length' bytes wide
* \param tag buffer for holding the tag
* \param tag_len length of the tag to generate in bytes
* must be 4, 6, 8, 10, 14 or 16
*
* \note The tag is written to a separete buffer. To get the tag
* concatenated with the output as in the CCM spec, use
* tag = output + length and make sure the output buffer is
* at least length + tag_len wide.
*
* \return 0 if successful
*/
int ccm_crypt_and_tag( ccm_context *ctx, size_t length,
const unsigned char *iv, size_t iv_len,
const unsigned char *add, size_t add_len,
const unsigned char *input, unsigned char *output,
unsigned char *tag, size_t tag_len );
#if defined(POLARSSL_SELF_TEST) && defined(POLARSSL_AES_C)
/**
* \brief Checkup routine

284
library/ccm.c
View File

@ -81,6 +81,206 @@ void ccm_free( ccm_context *ctx )
memset( ctx, 0, sizeof( ccm_context ) );
}
#define UPDATE_CBC_MAC( src ) \
{ \
size_t olen; \
\
for( i = 0; i < 16; i++ ) \
src[i] ^= y[i]; \
\
if( ( ret = cipher_update( &ctx->cipher_ctx, src, 16, \
y, &olen ) ) != 0 ) \
{ \
return( ret ); \
} \
}
#define CTR_CRYPT_BLOCK( dst, src ) \
{ \
size_t olen; \
\
if( ( ret = cipher_update( &ctx->cipher_ctx, ctr, 16, \
dst, &olen ) ) != 0 ) \
{ \
return( ret ); \
} \
\
for( i = 0; i < 16; i++ ) \
dst[i] ^= src[i]; \
}
/*
* Authenticated encryption
*/
int ccm_crypt_and_tag( ccm_context *ctx, size_t length,
const unsigned char *iv, size_t iv_len,
const unsigned char *add, size_t add_len,
const unsigned char *input, unsigned char *output,
unsigned char *tag, size_t tag_len )
{
int ret;
unsigned char i;
unsigned char q = 16 - 1 - iv_len;
size_t len_left;
unsigned char b[16];
unsigned char y[16];
unsigned char ctr[16];
const unsigned char *src;
unsigned char *dst;
/*
* Check length requirements: SP800-38C A.1
* Additional requirement: a < 2^16 - 2^8 to simplify the code.
* 'length' checked later (when writing it to the first block)
*/
if( tag_len < 4 || tag_len > 16 || tag_len % 2 != 0 )
return( POLARSSL_ERR_CCM_BAD_INPUT );
/* Also implies q is within bounds */
if( iv_len < 7 || iv_len > 13 )
return( POLARSSL_ERR_CCM_BAD_INPUT );
if( add_len > 0xFF00 )
return( POLARSSL_ERR_CCM_BAD_INPUT );
/*
* First block B_0:
* 0 .. 0 flags
* 1 .. iv_len nonce (aka iv)
* iv_len+1 .. 15 length
*
* With flags as (bits):
* 7 0
* 6 add present?
* 5 .. 3 (t - 2) / 2
* 2 .. 0 q - 1
*/
b[0] = 0;
b[0] |= ( add_len > 0 ) << 6;
b[0] |= ( ( tag_len - 2 ) / 2 ) << 3;
b[0] |= q - 1;
memcpy( b + 1, iv, iv_len );
for( i = 0, len_left = length; i < q; i++, len_left >>= 8 )
b[15-i] = (unsigned char)( len_left & 0xFF );
if( len_left > 0 )
return( POLARSSL_ERR_CCM_BAD_INPUT );
/* Start CBC-MAC with first block */
memset( y, 0, 16 );
UPDATE_CBC_MAC( b );
/*
* If there is additional data, update CBC-MAC with
* add_len, add, 0 (padding to a block boundary)
*/
if( add_len > 0 )
{
size_t use_len;
len_left = add_len;
src = add;
memset( b, 0, 16 );
b[0] = (unsigned char)( ( add_len >> 8 ) & 0xFF );
b[1] = (unsigned char)( ( add_len ) & 0xFF );
use_len = len_left < 16 - 2 ? len_left : 16 - 2;
memcpy( b + 2, src, use_len );
len_left -= use_len;
src += use_len;
UPDATE_CBC_MAC( b );
while( len_left > 16 )
{
memcpy( b, src, 16 );
UPDATE_CBC_MAC( b );
len_left -= 16;
src += 16;
}
if( len_left > 0 )
{
memset( b, 0, 16 );
memcpy( b, src, len_left );
UPDATE_CBC_MAC( b );
}
}
/*
* Counter block:
* 0 .. 0 flags
* 1 .. iv_len nonce (aka iv)
* iv_len+1 .. 15 counter (initially 1)
*
* With flags as (bits):
* 7 .. 3 0
* 2 .. 0 q - 1
*/
ctr[0] = q - 1;
memcpy( ctr + 1, iv, iv_len );
memset( ctr + 1 + iv_len, 0, q );
ctr[15] = 1;
len_left = length;
src = input;
dst = output;
/*
* Authenticate and encrypt message
*/
while( len_left > 16 )
{
memcpy( b, src, 16 );
UPDATE_CBC_MAC( b );
CTR_CRYPT_BLOCK( dst, src );
dst += 16;
src += 16;
len_left -= 16;
for( i = 0; i < q; i++ )
if( ++ctr[15-i] != 0 )
break;
}
if( len_left > 0 )
{
unsigned char mask[16];
size_t olen;
memset( b, 0, 16 );
memcpy( b, src, len_left );
UPDATE_CBC_MAC( b );
if( ( ret = cipher_update( &ctx->cipher_ctx, ctr, 16,
mask, &olen ) ) != 0 )
{
return( ret );
}
for( i = 0; i < len_left; i++ )
dst[i] = src[i] ^ mask[i];
}
/*
* Authentication: reset counter and encrypt internal tag
*/
for( i = 0; i < q; i++ )
ctr[15-i] = 0;
CTR_CRYPT_BLOCK( b, y );
memcpy( tag, b, tag_len );
return( 0 );
}
#if defined(POLARSSL_SELF_TEST) && defined(POLARSSL_AES_C)
@ -90,10 +290,92 @@ void ccm_free( ccm_context *ctx )
#define polarssl_printf printf
#endif
/*
* Examples 1 to 3 from SP800-38C Appendix C
*/
#define NB_TESTS 3
/*
* The data is the same for all tests, only the used length changes
*/
static const unsigned char key[] = {
0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
};
static const unsigned char iv[] = {
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
0x18, 0x19, 0x1a, 0x1b
};
static const unsigned char ad[] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
0x10, 0x11, 0x12, 0x13
};
static const unsigned char msg[] = {
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
};
static const size_t iv_len [NB_TESTS] = { 7, 8, 12 };
static const size_t add_len[NB_TESTS] = { 8, 16, 20 };
static const size_t msg_len[NB_TESTS] = { 4, 16, 24 };
static const size_t tag_len[NB_TESTS] = { 4, 6, 8 };
static const unsigned char res[NB_TESTS][32] = {
{ 0x71, 0x62, 0x01, 0x5b, 0x4d, 0xac, 0x25, 0x5d },
{ 0xd2, 0xa1, 0xf0, 0xe0, 0x51, 0xea, 0x5f, 0x62,
0x08, 0x1a, 0x77, 0x92, 0x07, 0x3d, 0x59, 0x3d,
0x1f, 0xc6, 0x4f, 0xbf, 0xac, 0xcd },
{ 0xe3, 0xb2, 0x01, 0xa9, 0xf5, 0xb7, 0x1a, 0x7a,
0x9b, 0x1c, 0xea, 0xec, 0xcd, 0x97, 0xe7, 0x0b,
0x61, 0x76, 0xaa, 0xd9, 0xa4, 0x42, 0x8a, 0xa5,
0x48, 0x43, 0x92, 0xfb, 0xc1, 0xb0, 0x99, 0x51 }
};
int ccm_self_test( int verbose )
{
ccm_context ctx;
unsigned char out[32];
size_t i;
int ret;
if( ccm_init( &ctx, POLARSSL_CIPHER_ID_AES, key, 8 * sizeof key ) != 0 )
{
if( verbose != 0 )
polarssl_printf( " CCM: skip\n" );
polarssl_printf( " CCM: setup failed" );
return( 1 );
}
for( i = 0; i < NB_TESTS; i++ )
{
if( verbose != 0 )
polarssl_printf( " CCM-AES #%u: ", (unsigned int) i + 1 );
ret = ccm_crypt_and_tag( &ctx, msg_len[i],
iv, iv_len[i], ad, add_len[i],
msg, out,
out + msg_len[i], tag_len[i] );
if( ret != 0 ||
memcmp( out, res[i], msg_len[i] + tag_len[i] ) != 0 )
{
if( verbose != 0 )
polarssl_printf( "failed\n" );
return( 1 );
}
if( verbose != 0 )
polarssl_printf( "passed\n" );
}
ccm_free( &ctx );
if( verbose != 0 )
polarssl_printf( "\n" );

96
tests/suites/test_suite_ccm.data
View File

@ -16,3 +16,99 @@ ccm_init:POLARSSL_CIPHER_ID_AES:224:POLARSSL_ERR_CCM_BAD_INPUT
CCM init #4 BLOWFISH-128: bad block size
depends_on:POLARSSL_BLOWFISH_C
ccm_init:POLARSSL_CIPHER_ID_BLOWFISH:128:POLARSSL_ERR_CCM_BAD_INPUT
CCM encrypt and tag RFC 3610 #1
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"08090A0B0C0D0E0F101112131415161718191A1B1C1D1E":"00000003020100A0A1A2A3A4A5":"0001020304050607":"588C979A61C663D2F066D0C2C0F989806D5F6B61DAC38417E8D12CFDF926E0"
CCM encrypt and tag RFC 3610 #2
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"08090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F":"00000004030201A0A1A2A3A4A5":"0001020304050607":"72C91A36E135F8CF291CA894085C87E3CC15C439C9E43A3BA091D56E10400916"
CCM encrypt and tag RFC 3610 #3
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"08090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F20":"00000005040302A0A1A2A3A4A5":"0001020304050607":"51B1E5F44A197D1DA46B0F8E2D282AE871E838BB64DA8596574ADAA76FBD9FB0C5"
CCM encrypt and tag RFC 3610 #4
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"0C0D0E0F101112131415161718191A1B1C1D1E":"00000006050403A0A1A2A3A4A5":"000102030405060708090A0B":"A28C6865939A9A79FAAA5C4C2A9D4A91CDAC8C96C861B9C9E61EF1"
CCM encrypt and tag RFC 3610 #5
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"0C0D0E0F101112131415161718191A1B1C1D1E1F":"00000007060504A0A1A2A3A4A5":"000102030405060708090A0B":"DCF1FB7B5D9E23FB9D4E131253658AD86EBDCA3E51E83F077D9C2D93"
CCM encrypt and tag RFC 3610 #6
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"0C0D0E0F101112131415161718191A1B1C1D1E1F20":"00000008070605A0A1A2A3A4A5":"000102030405060708090A0B":"6FC1B011F006568B5171A42D953D469B2570A4BD87405A0443AC91CB94"
CCM encrypt and tag RFC 3610 #7
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"08090A0B0C0D0E0F101112131415161718191A1B1C1D1E":"00000009080706A0A1A2A3A4A5":"0001020304050607":"0135D1B2C95F41D5D1D4FEC185D166B8094E999DFED96C048C56602C97ACBB7490"
CCM encrypt and tag RFC 3610 #8
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"08090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F":"0000000A090807A0A1A2A3A4A5":"0001020304050607":"7B75399AC0831DD2F0BBD75879A2FD8F6CAE6B6CD9B7DB24C17B4433F434963F34B4"
CCM encrypt and tag RFC 3610 #9
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"08090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F20":"0000000B0A0908A0A1A2A3A4A5":"0001020304050607":"82531A60CC24945A4B8279181AB5C84DF21CE7F9B73F42E197EA9C07E56B5EB17E5F4E"
CCM encrypt and tag RFC 3610 #10
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"0C0D0E0F101112131415161718191A1B1C1D1E":"0000000C0B0A09A0A1A2A3A4A5":"000102030405060708090A0B":"07342594157785152B074098330ABB141B947B566AA9406B4D999988DD"
CCM encrypt and tag RFC 3610 #11
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"0C0D0E0F101112131415161718191A1B1C1D1E1F":"0000000D0C0B0AA0A1A2A3A4A5":"000102030405060708090A0B":"676BB20380B0E301E8AB79590A396DA78B834934F53AA2E9107A8B6C022C"
CCM encrypt and tag RFC 3610 #12
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"0C0D0E0F101112131415161718191A1B1C1D1E1F20":"0000000E0D0C0BA0A1A2A3A4A5":"000102030405060708090A0B":"C0FFA0D6F05BDB67F24D43A4338D2AA4BED7B20E43CD1AA31662E7AD65D6DB"
CCM encrypt and tag RFC 3610 #13
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"08E8CF97D820EA258460E96AD9CF5289054D895CEAC47C":"00412B4EA9CDBE3C9696766CFA":"0BE1A88BACE018B1":"4CB97F86A2A4689A877947AB8091EF5386A6FFBDD080F8E78CF7CB0CDDD7B3"
CCM encrypt and tag RFC 3610 #14
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"9020EA6F91BDD85AFA0039BA4BAFF9BFB79C7028949CD0EC":"0033568EF7B2633C9696766CFA":"63018F76DC8A1BCB":"4CCB1E7CA981BEFAA0726C55D378061298C85C92814ABC33C52EE81D7D77C08A"
CCM encrypt and tag RFC 3610 #15
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"B916E0EACC1C00D7DCEC68EC0B3BBB1A02DE8A2D1AA346132E":"00103FE41336713C9696766CFA":"AA6CFA36CAE86B40":"B1D23A2220DDC0AC900D9AA03C61FCF4A559A4417767089708A776796EDB723506"
CCM encrypt and tag RFC 3610 #16
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"12DAAC5630EFA5396F770CE1A66B21F7B2101C":"00764C63B8058E3C9696766CFA":"D0D0735C531E1BECF049C244":"14D253C3967B70609B7CBB7C499160283245269A6F49975BCADEAF"
CCM encrypt and tag RFC 3610 #17
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"E88B6A46C78D63E52EB8C546EFB5DE6F75E9CC0D":"00F8B678094E3B3C9696766CFA":"77B60F011C03E1525899BCAE":"5545FF1A085EE2EFBF52B2E04BEE1E2336C73E3F762C0C7744FE7E3C"
CCM encrypt and tag RFC 3610 #18
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"6435ACBAFB11A82E2F071D7CA4A5EBD93A803BA87F":"00D560912D3F703C9696766CFA":"CD9044D2B71FDB8120EA60C0":"009769ECABDF48625594C59251E6035722675E04C847099E5AE0704551"
CCM encrypt and tag RFC 3610 #19
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"8A19B950BCF71A018E5E6701C91787659809D67DBEDD18":"0042FFF8F1951C3C9696766CFA":"D85BC7E69F944FB8":"BC218DAA947427B6DB386A99AC1AEF23ADE0B52939CB6A637CF9BEC2408897C6BA"
CCM encrypt and tag RFC 3610 #20
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"1761433C37C5A35FC1F39F406302EB907C6163BE38C98437":"00920F40E56CDC3C9696766CFA":"74A0EBC9069F5B37":"5810E6FD25874022E80361A478E3E9CF484AB04F447EFFF6F0A477CC2FC9BF548944"
CCM encrypt and tag RFC 3610 #21
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"A434A8E58500C6E41530538862D686EA9E81301B5AE4226BFA":"0027CA0C7120BC3C9696766CFA":"44A3AA3AAE6475CA":"F2BEED7BC5098E83FEB5B31608F8E29C38819A89C8E776F1544D4151A4ED3A8B87B9CE"
CCM encrypt and tag RFC 3610 #22
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"B96B49E21D621741632875DB7F6C9243D2D7C2":"005B8CCBCD9AF83C9696766CFA":"EC46BB63B02520C33C49FD70":"31D750A09DA3ED7FDDD49A2032AABF17EC8EBF7D22C8088C666BE5C197"
CCM encrypt and tag RFC 3610 #23
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"E2FCFBB880442C731BF95167C8FFD7895E337076":"003EBE94044B9A3C9696766CFA":"47A65AC78B3D594227E85E71":"E882F1DBD38CE3EDA7C23F04DD65071EB41342ACDF7E00DCCEC7AE52987D"
CCM encrypt and tag RFC 3610 #24
depends_on:POLARSSL_AES_C
ccm_encrypt_and_tag:POLARSSL_CIPHER_ID_AES:"D7828D13B2B0BDC325A76236DF93CC6B":"ABF21C0B02FEB88F856DF4A37381BCE3CC128517D4":"008D493B30AE8B3C9696766CFA":"6E37A6EF546D955D34AB6059":"F32905B88A641B04B9C9FFB58CC390900F3DA12AB16DCE9E82EFA16DA62059"

43
tests/suites/test_suite_ccm.function
View File

@ -30,3 +30,46 @@ void ccm_init( int cipher_id, int key_size, int result )
ccm_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void ccm_encrypt_and_tag( int cipher_id,
char *key_hex, char *msg_hex,
char *iv_hex, char *add_hex,
char *result_hex )
{
unsigned char key[128];
unsigned char msg[128];
unsigned char iv[128];
unsigned char add[128];
unsigned char output[144];
unsigned char result[144];
ccm_context ctx;
size_t key_len, msg_len, iv_len, add_len, tag_len, result_len;
memset( key, 0x00, sizeof( key ) );
memset( msg, 0x00, sizeof( msg ) );
memset( iv, 0x00, sizeof( iv ) );
memset( add, 0x00, sizeof( add ) );
memset( output, 0x00, sizeof( output ) );
memset( result, 0x00, sizeof( result ) );
key_len = unhexify( key, key_hex );
msg_len = unhexify( msg, msg_hex );
iv_len = unhexify( iv, iv_hex );
add_len = unhexify( add, add_hex );
result_len = unhexify( result, result_hex );
tag_len = result_len - msg_len;
TEST_ASSERT( ccm_init( &ctx, cipher_id, key, key_len * 8 ) == 0 );
TEST_ASSERT( ccm_crypt_and_tag( &ctx, msg_len, iv, iv_len, add, add_len,
msg, output, output + msg_len, tag_len ) == 0 );
TEST_ASSERT( memcmp( output, result, result_len ) == 0 );
/* Check we didn't write past the end */
TEST_ASSERT( output[result_len] == 0 && output[result_len + 1] == 0 );
ccm_free( &ctx );
}
/* END_CASE */