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;