diff options
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/ctr.c | 64 |
1 files changed, 33 insertions, 31 deletions
diff --git a/crypto/ctr.c b/crypto/ctr.c index b816e95..57da7d0 100644 --- a/crypto/ctr.c +++ b/crypto/ctr.c @@ -59,6 +59,21 @@ static int crypto_ctr_setkey(struct crypto_tfm *parent, const u8 *key, return err; } +static void crypto_ctr_crypt_final(struct blkcipher_walk *walk, + struct crypto_cipher *tfm, u8 *ctrblk, + unsigned int countersize) +{ + unsigned int bsize = crypto_cipher_blocksize(tfm); + u8 *keystream = ctrblk + bsize; + u8 *src = walk->src.virt.addr; + u8 *dst = walk->dst.virt.addr; + unsigned int nbytes = walk->nbytes; + + crypto_cipher_encrypt_one(tfm, keystream, ctrblk); + crypto_xor(keystream, src, nbytes); + memcpy(dst, keystream, nbytes); +} + static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk, struct crypto_cipher *tfm, u8 *ctrblk, unsigned int countersize) @@ -66,35 +81,23 @@ static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk, void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = crypto_cipher_alg(tfm)->cia_encrypt; unsigned int bsize = crypto_cipher_blocksize(tfm); - unsigned long alignmask = crypto_cipher_alignmask(tfm) | - (__alignof__(u32) - 1); - u8 ks[bsize + alignmask]; - u8 *keystream = (u8 *)ALIGN((unsigned long)ks, alignmask + 1); u8 *src = walk->src.virt.addr; u8 *dst = walk->dst.virt.addr; unsigned int nbytes = walk->nbytes; do { /* create keystream */ - fn(crypto_cipher_tfm(tfm), keystream, ctrblk); - crypto_xor(keystream, src, min(nbytes, bsize)); - - /* copy result into dst */ - memcpy(dst, keystream, min(nbytes, bsize)); + fn(crypto_cipher_tfm(tfm), dst, ctrblk); + crypto_xor(dst, src, bsize); /* increment counter in counterblock */ crypto_inc(ctrblk + bsize - countersize, countersize); - if (nbytes < bsize) - break; - src += bsize; dst += bsize; - nbytes -= bsize; - - } while (nbytes); + } while ((nbytes -= bsize) >= bsize); - return 0; + return nbytes; } static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk, @@ -104,30 +107,22 @@ static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk, void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = crypto_cipher_alg(tfm)->cia_encrypt; unsigned int bsize = crypto_cipher_blocksize(tfm); - unsigned long alignmask = crypto_cipher_alignmask(tfm) | - (__alignof__(u32) - 1); unsigned int nbytes = walk->nbytes; u8 *src = walk->src.virt.addr; - u8 ks[bsize + alignmask]; - u8 *keystream = (u8 *)ALIGN((unsigned long)ks, alignmask + 1); + u8 *keystream = ctrblk + bsize; do { /* create keystream */ fn(crypto_cipher_tfm(tfm), keystream, ctrblk); - crypto_xor(src, keystream, min(nbytes, bsize)); + crypto_xor(src, keystream, bsize); /* increment counter in counterblock */ crypto_inc(ctrblk + bsize - countersize, countersize); - if (nbytes < bsize) - break; - src += bsize; - nbytes -= bsize; + } while ((nbytes -= bsize) >= bsize); - } while (nbytes); - - return 0; + return nbytes; } static int crypto_ctr_crypt(struct blkcipher_desc *desc, @@ -143,7 +138,7 @@ static int crypto_ctr_crypt(struct blkcipher_desc *desc, crypto_instance_ctx(crypto_tfm_alg_instance(&tfm->base)); unsigned long alignmask = crypto_cipher_alignmask(child) | (__alignof__(u32) - 1); - u8 cblk[bsize + alignmask]; + u8 cblk[bsize * 2 + alignmask]; u8 *counterblk = (u8 *)ALIGN((unsigned long)cblk, alignmask + 1); int err; @@ -158,7 +153,7 @@ static int crypto_ctr_crypt(struct blkcipher_desc *desc, /* initialize counter portion of counter block */ crypto_inc(counterblk + bsize - ictx->countersize, ictx->countersize); - while (walk.nbytes) { + while (walk.nbytes >= bsize) { if (walk.src.virt.addr == walk.dst.virt.addr) nbytes = crypto_ctr_crypt_inplace(&walk, child, counterblk, @@ -170,6 +165,13 @@ static int crypto_ctr_crypt(struct blkcipher_desc *desc, err = blkcipher_walk_done(desc, &walk, nbytes); } + + if (walk.nbytes) { + crypto_ctr_crypt_final(&walk, child, counterblk, + ictx->countersize); + err = blkcipher_walk_done(desc, &walk, 0); + } + return err; } @@ -277,7 +279,7 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb) inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER; inst->alg.cra_priority = alg->cra_priority; inst->alg.cra_blocksize = 1; - inst->alg.cra_alignmask = __alignof__(u32) - 1; + inst->alg.cra_alignmask = alg->cra_alignmask | (__alignof__(u32) - 1); inst->alg.cra_type = &crypto_blkcipher_type; inst->alg.cra_blkcipher.ivsize = ivsize; |
