generic-library/openssl
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Eliminate redundant memcpy of IV material. Performance improvement varies

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from platform to platform and can be as large as 20%.
This commit is contained in:
Andy Polyakov 2004-12-26 12:31:37 +00:00
parent 556b8f3f77
commit 131e064e4a
1 changed files with 25 additions and 7 deletions
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32
crypto/aes/aes_cbc.c
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@ -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);