diff --git a/src/crypto/ctaes/ctaes.c b/src/crypto/ctaes/ctaes.c index 2389fc0bb..55962bf25 100644 --- a/src/crypto/ctaes/ctaes.c +++ b/src/crypto/ctaes/ctaes.c @@ -134,7 +134,7 @@ static void SubBytes(AES_state *s, int inv) { D = U7; } - /* Non-linear transformation (identical to the code in SubBytes) */ + /* Non-linear transformation (shared between the forward and backward case) */ M1 = T13 & T6; M6 = T3 & T16; M11 = T1 & T15; @@ -469,9 +469,9 @@ static void AES_encrypt(const AES_state* rounds, int nrounds, unsigned char* cip static void AES_decrypt(const AES_state* rounds, int nrounds, unsigned char* plain16, const unsigned char* cipher16) { /* Most AES decryption implementations use the alternate scheme - * (the Equivalent Inverse Cipher), which looks more like encryption, but - * needs different round constants. We can't reuse any code here anyway, so - * don't bother. */ + * (the Equivalent Inverse Cipher), which allows for more code reuse between + * the encryption and decryption code, but requires separate setup for both. + */ AES_state s = {{0}}; int round;