diff options
Diffstat (limited to 'crypto/cbc.c')
| -rw-r--r-- | crypto/cbc.c | 109 |
1 files changed, 25 insertions, 84 deletions
diff --git a/crypto/cbc.c b/crypto/cbc.c index 1f2649e13b42..6affff882cf8 100644 --- a/crypto/cbc.c +++ b/crypto/cbc.c @@ -14,13 +14,13 @@ #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> +#include <linux/log2.h> #include <linux/module.h> #include <linux/scatterlist.h> #include <linux/slab.h> struct crypto_cbc_ctx { struct crypto_cipher *child; - void (*xor)(u8 *dst, const u8 *src, unsigned int bs); }; static int crypto_cbc_setkey(struct crypto_tfm *parent, const u8 *key, @@ -41,9 +41,7 @@ static int crypto_cbc_setkey(struct crypto_tfm *parent, const u8 *key, static int crypto_cbc_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; @@ -54,7 +52,7 @@ static int crypto_cbc_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); @@ -67,9 +65,7 @@ static int crypto_cbc_encrypt_segment(struct blkcipher_desc *desc, static int crypto_cbc_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; @@ -79,7 +75,7 @@ static int crypto_cbc_encrypt_inplace(struct blkcipher_desc *desc, u8 *iv = walk->iv; do { - xor(src, iv, bsize); + crypto_xor(src, iv, bsize); fn(crypto_cipher_tfm(tfm), src, src); iv = src; @@ -99,7 +95,6 @@ static int crypto_cbc_encrypt(struct blkcipher_desc *desc, struct crypto_blkcipher *tfm = desc->tfm; struct crypto_cbc_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); @@ -107,11 +102,9 @@ static int crypto_cbc_encrypt(struct blkcipher_desc *desc, while ((nbytes = walk.nbytes)) { if (walk.src.virt.addr == walk.dst.virt.addr) - nbytes = crypto_cbc_encrypt_inplace(desc, &walk, child, - xor); + nbytes = crypto_cbc_encrypt_inplace(desc, &walk, child); else - nbytes = crypto_cbc_encrypt_segment(desc, &walk, child, - xor); + nbytes = crypto_cbc_encrypt_segment(desc, &walk, child); err = blkcipher_walk_done(desc, &walk, nbytes); } @@ -120,9 +113,7 @@ static int crypto_cbc_encrypt(struct blkcipher_desc *desc, static int crypto_cbc_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; @@ -134,7 +125,7 @@ static int crypto_cbc_decrypt_segment(struct blkcipher_desc *desc, do { fn(crypto_cipher_tfm(tfm), dst, src); - xor(dst, iv, bsize); + crypto_xor(dst, iv, bsize); iv = src; src += bsize; @@ -148,34 +139,29 @@ static int crypto_cbc_decrypt_segment(struct blkcipher_desc *desc, static int crypto_cbc_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; int bsize = crypto_cipher_blocksize(tfm); - unsigned long alignmask = crypto_cipher_alignmask(tfm); unsigned int nbytes = walk->nbytes; u8 *src = walk->src.virt.addr; - u8 stack[bsize + alignmask]; - u8 *first_iv = (u8 *)ALIGN((unsigned long)stack, alignmask + 1); - - memcpy(first_iv, walk->iv, bsize); + u8 last_iv[bsize]; /* Start of the last block. */ - src += nbytes - nbytes % bsize - bsize; - memcpy(walk->iv, src, bsize); + src += nbytes - (nbytes & (bsize - 1)) - bsize; + memcpy(last_iv, src, bsize); for (;;) { fn(crypto_cipher_tfm(tfm), src, src); if ((nbytes -= bsize) < bsize) break; - xor(src, src - bsize, bsize); + crypto_xor(src, src - bsize, bsize); src -= bsize; } - xor(src, first_iv, bsize); + crypto_xor(src, walk->iv, bsize); + memcpy(walk->iv, last_iv, bsize); return nbytes; } @@ -188,7 +174,6 @@ static int crypto_cbc_decrypt(struct blkcipher_desc *desc, struct crypto_blkcipher *tfm = desc->tfm; struct crypto_cbc_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); @@ -196,48 +181,15 @@ static int crypto_cbc_decrypt(struct blkcipher_desc *desc, while ((nbytes = walk.nbytes)) { if (walk.src.virt.addr == walk.dst.virt.addr) - nbytes = crypto_cbc_decrypt_inplace(desc, &walk, child, - xor); + nbytes = crypto_cbc_decrypt_inplace(desc, &walk, child); else - nbytes = crypto_cbc_decrypt_segment(desc, &walk, child, - xor); + nbytes = crypto_cbc_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_cbc_init_tfm(struct crypto_tfm *tfm) { struct crypto_instance *inst = (void *)tfm->__crt_alg; @@ -245,22 +197,6 @@ static int crypto_cbc_init_tfm(struct crypto_tfm *tfm) struct crypto_cbc_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); @@ -290,6 +226,10 @@ static struct crypto_instance *crypto_cbc_alloc(struct rtattr **tb) if (IS_ERR(alg)) return ERR_PTR(PTR_ERR(alg)); + inst = ERR_PTR(-EINVAL); + if (!is_power_of_2(alg->cra_blocksize)) + goto out_put_alg; + inst = crypto_alloc_instance("cbc", alg); if (IS_ERR(inst)) goto out_put_alg; @@ -300,8 +240,9 @@ static struct crypto_instance *crypto_cbc_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; 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