diff options
| author | Jack Lloyd <[email protected]> | 2020-05-06 20:28:17 -0400 |
|---|---|---|
| committer | Jack Lloyd <[email protected]> | 2020-05-08 06:19:59 -0400 |
| commit | 4a895ebf662403cccb2451f9905dd105ca46fe13 (patch) | |
| tree | 30a167ec5dd3811ab163870853fe625d909b44b3 | |
| parent | c06cb332d7039256a9d3c0c3aa4024e1e37b7626 (diff) | |
Avoid extra resize during AES key schedule
| -rw-r--r-- | src/lib/block/aes/aes.cpp | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/src/lib/block/aes/aes.cpp b/src/lib/block/aes/aes.cpp index 21f580641..b1792561f 100644 --- a/src/lib/block/aes/aes.cpp +++ b/src/lib/block/aes/aes.cpp @@ -660,8 +660,8 @@ void aes_key_schedule(const uint8_t key[], size_t length, CT::poison(key, length); - EK.resize(length + 32); - DK.resize(length + 32); + EK.resize(length + 28); + DK.resize(length + 28); for(size_t i = 0; i != X; ++i) EK[i] = load_be<uint32_t>(key, i); @@ -670,7 +670,7 @@ void aes_key_schedule(const uint8_t key[], size_t length, { EK[i] = EK[i-X] ^ RC[(i-X)/X] ^ rotl<8>(SE_word(EK[i-1])); - for(size_t j = 1; j != X; ++j) + for(size_t j = 1; j != X && (i+j) < EK.size(); ++j) { EK[i+j] = EK[i+j-X]; @@ -689,7 +689,7 @@ void aes_key_schedule(const uint8_t key[], size_t length, DK[i+3] = EK[4*rounds-i+3]; } - for(size_t i = 4; i != length + 24; ++i) + for(size_t i = 4; i != DK.size() - 4; ++i) { const uint8_t s0 = get_byte(0, DK[i]); const uint8_t s1 = get_byte(1, DK[i]); @@ -702,9 +702,6 @@ void aes_key_schedule(const uint8_t key[], size_t length, rotr<24>(InvMixColumn(s3)); } - EK.resize(length + 24 + 4); - DK.resize(length + 24 + 4); - if(bswap_keys) { // HW AES on little endian needs the subkeys to be byte reversed |