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Add chunked auth data support

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Signed-off-by: Mateusz Starzyk <mateusz.starzyk@mobica.com>
This commit is contained in:
Mateusz Starzyk 2021-07-06 15:38:35 +02:00
parent eb2ca96d69
commit 33392450b7
1 changed files with 30 additions and 29 deletions
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59
library/ccm.c
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@ -281,43 +281,44 @@ int mbedtls_ccm_update_ad( mbedtls_ccm_context *ctx,
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
unsigned char i;
size_t len_left, olen;
const unsigned char *src;
size_t olen, use_len, offset;
/*
* If there is additional data, update CBC-MAC with
* add_len, add, 0 (padding to a block boundary)
*/
if( add_len > 0 )
if( ctx->add_len > 0 && add_len > 0)
{
size_t use_len;
len_left = add_len;
src = add;
memset( ctx->b, 0, 16 );
ctx->b[0] = (unsigned char)( ( add_len >> 8 ) & 0xFF );
ctx->b[1] = (unsigned char)( ( add_len ) & 0xFF );
use_len = len_left < 16 - 2 ? len_left : 16 - 2;
memcpy( ctx->b + 2, src, use_len );
len_left -= use_len;
src += use_len;
UPDATE_CBC_MAC;
while( len_left > 0 )
if( ctx->processed == 0 )
{
use_len = len_left > 16 ? 16 : len_left;
memset( ctx->b, 0, 16 );
memcpy( ctx->b, src, use_len );
UPDATE_CBC_MAC;
ctx->b[0] = (unsigned char)( ( ctx->add_len >> 8 ) & 0xFF );
ctx->b[1] = (unsigned char)( ( ctx->add_len ) & 0xFF );
len_left -= use_len;
src += use_len;
ctx->processed += 2;
}
while( add_len > 0 )
{
offset = ctx->processed % 16;
use_len = 16 - offset;
if( use_len > add_len )
use_len = add_len;
memcpy( ctx->b + offset, add, use_len );
ctx->processed += use_len;
add_len -= use_len;
add += use_len;
if( use_len + offset == 16 || ctx->processed - 2 == ctx->add_len )
{
UPDATE_CBC_MAC;
memset( ctx->b, 0, 16 );
}
}
}
if( ctx->processed - 2 == ctx->add_len )
ctx->processed = 0; // prepare for mbedtls_ccm_update()
return (0);
}