From 131e064e4ae44288a5a84866deac2b19c88b7826 Mon Sep 17 00:00:00 2001 From: Andy Polyakov Date: Sun, 26 Dec 2004 12:31:37 +0000 Subject: [PATCH] Eliminate redundant memcpy of IV material. Performance improvement varies from platform to platform and can be as large as 20%. --- crypto/aes/aes_cbc.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) diff --git a/crypto/aes/aes_cbc.c b/crypto/aes/aes_cbc.c index 1222a21002..e43135e8a0 100644 --- a/crypto/aes/aes_cbc.c +++ b/crypto/aes/aes_cbc.c @@ -65,7 +65,7 @@ void AES_cbc_encrypt(const unsigned char *in, unsigned char *out, unsigned long n; unsigned long len = length; - unsigned char tmp[AES_BLOCK_SIZE]; + unsigned char tmp[AES_BLOCK_SIZE], *iv = ivec; assert(in && out && key && ivec); assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc)); @@ -73,22 +73,40 @@ void AES_cbc_encrypt(const unsigned char *in, unsigned char *out, if (AES_ENCRYPT == enc) { while (len >= AES_BLOCK_SIZE) { for(n=0; n < AES_BLOCK_SIZE; ++n) - tmp[n] = in[n] ^ ivec[n]; - AES_encrypt(tmp, out, key); - memcpy(ivec, out, AES_BLOCK_SIZE); + out[n] = in[n] ^ iv[n]; + AES_encrypt(out, out, key); + iv = out; len -= AES_BLOCK_SIZE; in += AES_BLOCK_SIZE; out += AES_BLOCK_SIZE; } if (len) { for(n=0; n < len; ++n) - tmp[n] = in[n] ^ ivec[n]; + tmp[n] = in[n] ^ iv[n]; for(n=len; n < AES_BLOCK_SIZE; ++n) - tmp[n] = ivec[n]; + tmp[n] = iv[n]; AES_encrypt(tmp, tmp, key); memcpy(out, tmp, AES_BLOCK_SIZE); - memcpy(ivec, tmp, AES_BLOCK_SIZE); + iv = out; } + memcpy(ivec,iv,AES_BLOCK_SIZE); + } else if (in != out) { + while (len >= AES_BLOCK_SIZE) { + AES_decrypt(in, out, key); + for(n=0; n < AES_BLOCK_SIZE; ++n) + out[n] ^= iv[n]; + iv = in; + len -= AES_BLOCK_SIZE; + in += AES_BLOCK_SIZE; + out += AES_BLOCK_SIZE; + } + if (len) { + AES_decrypt(in,tmp,key); + for(n=0; n < len; ++n) + out[n] = tmp[n] ^ iv[n]; + iv = in; + } + memcpy(ivec,iv,AES_BLOCK_SIZE); } else { while (len >= AES_BLOCK_SIZE) { memcpy(tmp, in, AES_BLOCK_SIZE); -- GitLab