From d0b9007a27206fe944d9db72e13dab157b8e118c Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 20 Nov 2007 17:49:49 +0800 Subject: [PATCH] [CRYPTO] pcbc: Use crypto_xor This patch replaces the custom xor in CBC with the generic crypto_xor. It changes the operations for in-place encryption slightly to avoid calling crypto_xor with tmpbuf since it is not necessarily aligned. Signed-off-by: Herbert Xu --- crypto/pcbc.c | 105 ++++++++++++-------------------------------------- 1 file changed, 24 insertions(+), 81 deletions(-) diff --git a/crypto/pcbc.c b/crypto/pcbc.c index c3ed8a1c9f..fe704775f8 100644 --- a/crypto/pcbc.c +++ b/crypto/pcbc.c @@ -24,7 +24,6 @@ struct crypto_pcbc_ctx { struct crypto_cipher *child; - void (*xor)(u8 *dst, const u8 *src, unsigned int bs); }; static int crypto_pcbc_setkey(struct crypto_tfm *parent, const u8 *key, @@ -45,9 +44,7 @@ static int crypto_pcbc_setkey(struct crypto_tfm *parent, const u8 *key, static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc, struct blkcipher_walk *walk, - struct crypto_cipher *tfm, - void (*xor)(u8 *, const u8 *, - unsigned int)) + struct crypto_cipher *tfm) { void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = crypto_cipher_alg(tfm)->cia_encrypt; @@ -58,10 +55,10 @@ static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc, u8 *iv = walk->iv; do { - xor(iv, src, bsize); + crypto_xor(iv, src, bsize); fn(crypto_cipher_tfm(tfm), dst, iv); memcpy(iv, dst, bsize); - xor(iv, src, bsize); + crypto_xor(iv, src, bsize); src += bsize; dst += bsize; @@ -72,9 +69,7 @@ static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc, static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc, struct blkcipher_walk *walk, - struct crypto_cipher *tfm, - void (*xor)(u8 *, const u8 *, - unsigned int)) + struct crypto_cipher *tfm) { void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = crypto_cipher_alg(tfm)->cia_encrypt; @@ -86,10 +81,10 @@ static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc, do { memcpy(tmpbuf, src, bsize); - xor(iv, tmpbuf, bsize); + crypto_xor(iv, src, bsize); fn(crypto_cipher_tfm(tfm), src, iv); - memcpy(iv, src, bsize); - xor(iv, tmpbuf, bsize); + memcpy(iv, tmpbuf, bsize); + crypto_xor(iv, src, bsize); src += bsize; } while ((nbytes -= bsize) >= bsize); @@ -107,7 +102,6 @@ static int crypto_pcbc_encrypt(struct blkcipher_desc *desc, struct crypto_blkcipher *tfm = desc->tfm; struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm); struct crypto_cipher *child = ctx->child; - void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor; int err; blkcipher_walk_init(&walk, dst, src, nbytes); @@ -115,11 +109,11 @@ static int crypto_pcbc_encrypt(struct blkcipher_desc *desc, while ((nbytes = walk.nbytes)) { if (walk.src.virt.addr == walk.dst.virt.addr) - nbytes = crypto_pcbc_encrypt_inplace(desc, &walk, child, - xor); + nbytes = crypto_pcbc_encrypt_inplace(desc, &walk, + child); else - nbytes = crypto_pcbc_encrypt_segment(desc, &walk, child, - xor); + nbytes = crypto_pcbc_encrypt_segment(desc, &walk, + child); err = blkcipher_walk_done(desc, &walk, nbytes); } @@ -128,9 +122,7 @@ static int crypto_pcbc_encrypt(struct blkcipher_desc *desc, static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc, struct blkcipher_walk *walk, - struct crypto_cipher *tfm, - void (*xor)(u8 *, const u8 *, - unsigned int)) + struct crypto_cipher *tfm) { void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = crypto_cipher_alg(tfm)->cia_decrypt; @@ -142,9 +134,9 @@ static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc, do { fn(crypto_cipher_tfm(tfm), dst, src); - xor(dst, iv, bsize); + crypto_xor(dst, iv, bsize); memcpy(iv, src, bsize); - xor(iv, dst, bsize); + crypto_xor(iv, dst, bsize); src += bsize; dst += bsize; @@ -157,9 +149,7 @@ static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc, static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc, struct blkcipher_walk *walk, - struct crypto_cipher *tfm, - void (*xor)(u8 *, const u8 *, - unsigned int)) + struct crypto_cipher *tfm) { void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = crypto_cipher_alg(tfm)->cia_decrypt; @@ -172,9 +162,9 @@ static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc, do { memcpy(tmpbuf, src, bsize); fn(crypto_cipher_tfm(tfm), src, src); - xor(src, iv, bsize); + crypto_xor(src, iv, bsize); memcpy(iv, tmpbuf, bsize); - xor(iv, src, bsize); + crypto_xor(iv, src, bsize); src += bsize; } while ((nbytes -= bsize) >= bsize); @@ -192,7 +182,6 @@ static int crypto_pcbc_decrypt(struct blkcipher_desc *desc, struct crypto_blkcipher *tfm = desc->tfm; struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm); struct crypto_cipher *child = ctx->child; - void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor; int err; blkcipher_walk_init(&walk, dst, src, nbytes); @@ -200,48 +189,17 @@ static int crypto_pcbc_decrypt(struct blkcipher_desc *desc, while ((nbytes = walk.nbytes)) { if (walk.src.virt.addr == walk.dst.virt.addr) - nbytes = crypto_pcbc_decrypt_inplace(desc, &walk, child, - xor); + nbytes = crypto_pcbc_decrypt_inplace(desc, &walk, + child); else - nbytes = crypto_pcbc_decrypt_segment(desc, &walk, child, - xor); + nbytes = crypto_pcbc_decrypt_segment(desc, &walk, + child); err = blkcipher_walk_done(desc, &walk, nbytes); } return err; } -static void xor_byte(u8 *a, const u8 *b, unsigned int bs) -{ - do { - *a++ ^= *b++; - } while (--bs); -} - -static void xor_quad(u8 *dst, const u8 *src, unsigned int bs) -{ - u32 *a = (u32 *)dst; - u32 *b = (u32 *)src; - - do { - *a++ ^= *b++; - } while ((bs -= 4)); -} - -static void xor_64(u8 *a, const u8 *b, unsigned int bs) -{ - ((u32 *)a)[0] ^= ((u32 *)b)[0]; - ((u32 *)a)[1] ^= ((u32 *)b)[1]; -} - -static void xor_128(u8 *a, const u8 *b, unsigned int bs) -{ - ((u32 *)a)[0] ^= ((u32 *)b)[0]; - ((u32 *)a)[1] ^= ((u32 *)b)[1]; - ((u32 *)a)[2] ^= ((u32 *)b)[2]; - ((u32 *)a)[3] ^= ((u32 *)b)[3]; -} - static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm) { struct crypto_instance *inst = (void *)tfm->__crt_alg; @@ -249,22 +207,6 @@ static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm) struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm); struct crypto_cipher *cipher; - switch (crypto_tfm_alg_blocksize(tfm)) { - case 8: - ctx->xor = xor_64; - break; - - case 16: - ctx->xor = xor_128; - break; - - default: - if (crypto_tfm_alg_blocksize(tfm) % 4) - ctx->xor = xor_byte; - else - ctx->xor = xor_quad; - } - cipher = crypto_spawn_cipher(spawn); if (IS_ERR(cipher)) return PTR_ERR(cipher); @@ -304,8 +246,9 @@ static struct crypto_instance *crypto_pcbc_alloc(struct rtattr **tb) inst->alg.cra_alignmask = alg->cra_alignmask; inst->alg.cra_type = &crypto_blkcipher_type; - if (!(alg->cra_blocksize % 4)) - inst->alg.cra_alignmask |= 3; + /* We access the data as u32s when xoring. */ + inst->alg.cra_alignmask |= __alignof__(u32) - 1; + inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize; inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize; inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize; -- 2.39.5