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Bug in AES CMAC calculation when using multiple tc_cmac_update() calls #1

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Bug in AES CMAC calculation when using multiple tc_cmac_update() calls #1

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4 changes: 2 additions & 2 deletions lib/source/cmac_mode.c
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Original file line number Diff line number Diff line change
Expand Up @@ -179,13 +179,13 @@ int tc_cmac_update(TCCmacState_t s, const uint8_t *data, size_t data_length)
/* last data added to s didn't end on a TC_AES_BLOCK_SIZE byte boundary */
size_t remaining_space = TC_AES_BLOCK_SIZE - s->leftover_offset;

if (data_length < remaining_space) {
if (data_length <= remaining_space) {
/* still not enough data to encrypt this time either */
_copy(&s->leftover[s->leftover_offset], data_length, data, data_length);
s->leftover_offset += data_length;
return TC_CRYPTO_SUCCESS;
}
/* leftover block is now full; encrypt it first */
/* leftover block is now full and there is addidional data; encrypt block first */
_copy(&s->leftover[s->leftover_offset],
remaining_space,
data,
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