Merge pull request #5213 from tom-cosgrove-arm/pr_4950

Fix GCM calculation with very long IV
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Gilles Peskine 2021-11-22 22:22:37 +01:00 committed by GitHub
commit 0c9f058504
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2 changed files with 7 additions and 1 deletions

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@ -0,0 +1,4 @@
Bugfix
* Fix a bug in mbedtls_gcm_starts() when bits of iv are longer than 2^32.
* Fix #4884.

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@ -254,6 +254,7 @@ int mbedtls_gcm_starts( mbedtls_gcm_context *ctx,
size_t i;
const unsigned char *p;
size_t use_len, olen = 0;
uint64_t iv_bits;
GCM_VALIDATE_RET( ctx != NULL );
GCM_VALIDATE_RET( iv != NULL );
@ -278,7 +279,8 @@ int mbedtls_gcm_starts( mbedtls_gcm_context *ctx,
else
{
memset( work_buf, 0x00, 16 );
MBEDTLS_PUT_UINT32_BE( iv_len * 8, work_buf, 12 );
iv_bits = (uint64_t)iv_len * 8;
MBEDTLS_PUT_UINT64_BE( iv_bits, work_buf, 8 );
p = iv;
while( iv_len > 0 )