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-rw-r--r--crypto/cbc.c144
1 files changed, 133 insertions, 11 deletions
diff --git a/crypto/cbc.c b/crypto/cbc.c
index e6f6273a7d39..0d9509dff891 100644
--- a/crypto/cbc.c
+++ b/crypto/cbc.c
@@ -6,7 +6,6 @@
*/
#include <crypto/algapi.h>
-#include <crypto/cbc.h>
#include <crypto/internal/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
@@ -14,34 +13,157 @@
#include <linux/log2.h>
#include <linux/module.h>
-static inline void crypto_cbc_encrypt_one(struct crypto_skcipher *tfm,
- const u8 *src, u8 *dst)
+static int crypto_cbc_encrypt_segment(struct skcipher_walk *walk,
+ struct crypto_skcipher *skcipher)
{
- crypto_cipher_encrypt_one(skcipher_cipher_simple(tfm), dst, src);
+ unsigned int bsize = crypto_skcipher_blocksize(skcipher);
+ void (*fn)(struct crypto_tfm *, u8 *, const u8 *);
+ unsigned int nbytes = walk->nbytes;
+ u8 *src = walk->src.virt.addr;
+ u8 *dst = walk->dst.virt.addr;
+ struct crypto_cipher *cipher;
+ struct crypto_tfm *tfm;
+ u8 *iv = walk->iv;
+
+ cipher = skcipher_cipher_simple(skcipher);
+ tfm = crypto_cipher_tfm(cipher);
+ fn = crypto_cipher_alg(cipher)->cia_encrypt;
+
+ do {
+ crypto_xor(iv, src, bsize);
+ fn(tfm, dst, iv);
+ memcpy(iv, dst, bsize);
+
+ src += bsize;
+ dst += bsize;
+ } while ((nbytes -= bsize) >= bsize);
+
+ return nbytes;
+}
+
+static int crypto_cbc_encrypt_inplace(struct skcipher_walk *walk,
+ struct crypto_skcipher *skcipher)
+{
+ unsigned int bsize = crypto_skcipher_blocksize(skcipher);
+ void (*fn)(struct crypto_tfm *, u8 *, const u8 *);
+ unsigned int nbytes = walk->nbytes;
+ u8 *src = walk->src.virt.addr;
+ struct crypto_cipher *cipher;
+ struct crypto_tfm *tfm;
+ u8 *iv = walk->iv;
+
+ cipher = skcipher_cipher_simple(skcipher);
+ tfm = crypto_cipher_tfm(cipher);
+ fn = crypto_cipher_alg(cipher)->cia_encrypt;
+
+ do {
+ crypto_xor(src, iv, bsize);
+ fn(tfm, src, src);
+ iv = src;
+
+ src += bsize;
+ } while ((nbytes -= bsize) >= bsize);
+
+ memcpy(walk->iv, iv, bsize);
+
+ return nbytes;
}
static int crypto_cbc_encrypt(struct skcipher_request *req)
{
- return crypto_cbc_encrypt_walk(req, crypto_cbc_encrypt_one);
+ struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+ struct skcipher_walk walk;
+ int err;
+
+ err = skcipher_walk_virt(&walk, req, false);
+
+ while (walk.nbytes) {
+ if (walk.src.virt.addr == walk.dst.virt.addr)
+ err = crypto_cbc_encrypt_inplace(&walk, skcipher);
+ else
+ err = crypto_cbc_encrypt_segment(&walk, skcipher);
+ err = skcipher_walk_done(&walk, err);
+ }
+
+ return err;
+}
+
+static int crypto_cbc_decrypt_segment(struct skcipher_walk *walk,
+ struct crypto_skcipher *skcipher)
+{
+ unsigned int bsize = crypto_skcipher_blocksize(skcipher);
+ void (*fn)(struct crypto_tfm *, u8 *, const u8 *);
+ unsigned int nbytes = walk->nbytes;
+ u8 *src = walk->src.virt.addr;
+ u8 *dst = walk->dst.virt.addr;
+ struct crypto_cipher *cipher;
+ struct crypto_tfm *tfm;
+ u8 *iv = walk->iv;
+
+ cipher = skcipher_cipher_simple(skcipher);
+ tfm = crypto_cipher_tfm(cipher);
+ fn = crypto_cipher_alg(cipher)->cia_decrypt;
+
+ do {
+ fn(tfm, dst, src);
+ crypto_xor(dst, iv, bsize);
+ iv = src;
+
+ src += bsize;
+ dst += bsize;
+ } while ((nbytes -= bsize) >= bsize);
+
+ memcpy(walk->iv, iv, bsize);
+
+ return nbytes;
}
-static inline void crypto_cbc_decrypt_one(struct crypto_skcipher *tfm,
- const u8 *src, u8 *dst)
+static int crypto_cbc_decrypt_inplace(struct skcipher_walk *walk,
+ struct crypto_skcipher *skcipher)
{
- crypto_cipher_decrypt_one(skcipher_cipher_simple(tfm), dst, src);
+ unsigned int bsize = crypto_skcipher_blocksize(skcipher);
+ void (*fn)(struct crypto_tfm *, u8 *, const u8 *);
+ unsigned int nbytes = walk->nbytes;
+ u8 *src = walk->src.virt.addr;
+ u8 last_iv[MAX_CIPHER_BLOCKSIZE];
+ struct crypto_cipher *cipher;
+ struct crypto_tfm *tfm;
+
+ cipher = skcipher_cipher_simple(skcipher);
+ tfm = crypto_cipher_tfm(cipher);
+ fn = crypto_cipher_alg(cipher)->cia_decrypt;
+
+ /* Start of the last block. */
+ src += nbytes - (nbytes & (bsize - 1)) - bsize;
+ memcpy(last_iv, src, bsize);
+
+ for (;;) {
+ fn(tfm, src, src);
+ if ((nbytes -= bsize) < bsize)
+ break;
+ crypto_xor(src, src - bsize, bsize);
+ src -= bsize;
+ }
+
+ crypto_xor(src, walk->iv, bsize);
+ memcpy(walk->iv, last_iv, bsize);
+
+ return nbytes;
}
static int crypto_cbc_decrypt(struct skcipher_request *req)
{
- struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
struct skcipher_walk walk;
int err;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes) {
- err = crypto_cbc_decrypt_blocks(&walk, tfm,
- crypto_cbc_decrypt_one);
+ if (walk.src.virt.addr == walk.dst.virt.addr)
+ err = crypto_cbc_decrypt_inplace(&walk, skcipher);
+ else
+ err = crypto_cbc_decrypt_segment(&walk, skcipher);
err = skcipher_walk_done(&walk, err);
}