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Merge pull request #359 from vchong/ltc_ctr 

ltc: ctr: improve performance
(cherry picked from commit 9b80d07487bed20575b9846ba0d4bcdc280ae8c0)
This commit is contained in:
Steffen Jaeckel 2018-03-27 02:25:25 +02:00 committed by Steffen Jaeckel
parent affb3d70cb
commit 24aab18d5b
1 changed files with 60 additions and 33 deletions
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93
src/modes/ctr/ctr_encrypt.c
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@ -17,47 +17,17 @@
#ifdef LTC_CTR_MODE
/**
CTR encrypt
CTR encrypt software implementation
@param pt Plaintext
@param ct [out] Ciphertext
@param len Length of plaintext (octets)
@param ctr CTR state
@return CRYPT_OK if successful
*/
int ctr_encrypt(const unsigned char *pt, unsigned char *ct, unsigned long len, symmetric_CTR *ctr)
static int _ctr_encrypt(const unsigned char *pt, unsigned char *ct, unsigned long len, symmetric_CTR *ctr)
{
int x, err;
LTC_ARGCHK(pt != NULL);
LTC_ARGCHK(ct != NULL);
LTC_ARGCHK(ctr != NULL);
if ((err = cipher_is_valid(ctr->cipher)) != CRYPT_OK) {
return err;
}
/* is blocklen/padlen valid? */
if (ctr->blocklen < 1 || ctr->blocklen > (int)sizeof(ctr->ctr) ||
ctr->padlen < 0 || ctr->padlen > (int)sizeof(ctr->pad)) {
return CRYPT_INVALID_ARG;
}
#ifdef LTC_FAST
if (ctr->blocklen % sizeof(LTC_FAST_TYPE)) {
return CRYPT_INVALID_ARG;
}
#endif
/* handle acceleration only if pad is empty, accelerator is present and length is >= a block size */
if ((ctr->padlen == ctr->blocklen) && cipher_descriptor[ctr->cipher].accel_ctr_encrypt != NULL && (len >= (unsigned long)ctr->blocklen)) {
if ((err = cipher_descriptor[ctr->cipher].accel_ctr_encrypt(pt, ct, len/ctr->blocklen, ctr->ctr, ctr->mode, &ctr->key)) != CRYPT_OK) {
return err;
}
pt += (len / ctr->blocklen) * ctr->blocklen;
ct += (len / ctr->blocklen) * ctr->blocklen;
len %= ctr->blocklen;
}
while (len) {
/* is the pad empty? */
if (ctr->padlen == ctr->blocklen) {
@ -87,7 +57,7 @@ int ctr_encrypt(const unsigned char *pt, unsigned char *ct, unsigned long len, s
ctr->padlen = 0;
}
#ifdef LTC_FAST
if (ctr->padlen == 0 && len >= (unsigned long)ctr->blocklen) {
if ((ctr->padlen == 0) && (len >= (unsigned long)ctr->blocklen)) {
for (x = 0; x < ctr->blocklen; x += sizeof(LTC_FAST_TYPE)) {
*(LTC_FAST_TYPE_PTR_CAST((unsigned char *)ct + x)) = *(LTC_FAST_TYPE_PTR_CAST((unsigned char *)pt + x)) ^
*(LTC_FAST_TYPE_PTR_CAST((unsigned char *)ctr->pad + x));
@ -105,6 +75,63 @@ int ctr_encrypt(const unsigned char *pt, unsigned char *ct, unsigned long len, s
return CRYPT_OK;
}
/**
CTR encrypt
@param pt Plaintext
@param ct [out] Ciphertext
@param len Length of plaintext (octets)
@param ctr CTR state
@return CRYPT_OK if successful
*/
int ctr_encrypt(const unsigned char *pt, unsigned char *ct, unsigned long len, symmetric_CTR *ctr)
{
int err, fr;
LTC_ARGCHK(pt != NULL);
LTC_ARGCHK(ct != NULL);
LTC_ARGCHK(ctr != NULL);
if ((err = cipher_is_valid(ctr->cipher)) != CRYPT_OK) {
return err;
}
/* is blocklen/padlen valid? */
if ((ctr->blocklen < 1) || (ctr->blocklen > (int)sizeof(ctr->ctr)) ||
(ctr->padlen < 0) || (ctr->padlen > (int)sizeof(ctr->pad))) {
return CRYPT_INVALID_ARG;
}
#ifdef LTC_FAST
if (ctr->blocklen % sizeof(LTC_FAST_TYPE)) {
return CRYPT_INVALID_ARG;
}
#endif
/* handle acceleration only if pad is empty, accelerator is present and length is >= a block size */
if ((cipher_descriptor[ctr->cipher].accel_ctr_encrypt != NULL) && (len >= (unsigned long)ctr->blocklen)) {
if (ctr->padlen < ctr->blocklen) {
fr = ctr->blocklen - ctr->padlen;
if ((err = _ctr_encrypt(pt, ct, fr, ctr)) != CRYPT_OK) {
return err;
}
pt += fr;
ct += fr;
len -= fr;
}
if (len >= (unsigned long)ctr->blocklen) {
if ((err = cipher_descriptor[ctr->cipher].accel_ctr_encrypt(pt, ct, len/ctr->blocklen, ctr->ctr, ctr->mode, &ctr->key)) != CRYPT_OK) {
return err;
}
pt += (len / ctr->blocklen) * ctr->blocklen;
ct += (len / ctr->blocklen) * ctr->blocklen;
len %= ctr->blocklen;
}
}
return _ctr_encrypt(pt, ct, len, ctr);
}
#endif
/* ref: $Format:%D$ */