bugfix: if the len of iv is not 96-bit, y0 can be calculated incorrectly

An initialization vector IV can have any number of bits between 1 and
2^64. So it should be filled to the lower 64-bit in the last step
when computing ghash.

Signed-off-by: openluopworld <luopengxq@gmail.com>
This commit is contained in:
openluopworld 2021-09-19 11:18:04 +08:00
parent 6c8183f0c9
commit 08fd463ee4

View file

@ -278,8 +278,7 @@ int mbedtls_gcm_starts( mbedtls_gcm_context *ctx,
else else
{ {
memset( work_buf, 0x00, 16 ); memset( work_buf, 0x00, 16 );
MBEDTLS_PUT_UINT32_BE( iv_len >> 29, work_buf, 8 ); MBEDTLS_PUT_UINT64_BE( iv_len * 8, work_buf, 8 );
MBEDTLS_PUT_UINT32_BE( iv_len << 3, work_buf, 12 );
p = iv; p = iv;
while( iv_len > 0 ) while( iv_len > 0 )