Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-block

[karo-tx-linux.git] / crypto / xts.c

diff --git a/crypto/xts.c b/crypto/xts.c
index 851705446c8201f13232ff3d8fce6956c99d72e4..ca1608f44cb56617d1b9e1d721d4a6dc12bca041 100644 (file)
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -21,6 +21,7 @@
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 
+#include <crypto/xts.h>
 #include <crypto/b128ops.h>
 #include <crypto/gf128mul.h>
 
@@ -96,7 +97,7 @@ static int crypt(struct blkcipher_desc *d,
 {
        int err;
        unsigned int avail;
-       const int bs = crypto_cipher_blocksize(ctx->child);
+       const int bs = XTS_BLOCK_SIZE;
        struct sinfo s = {
                .tfm = crypto_cipher_tfm(ctx->child),
                .fn = fn
@@ -165,6 +166,78 @@ static int decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
                     crypto_cipher_alg(ctx->child)->cia_decrypt);
 }
 
+int xts_crypt(struct blkcipher_desc *desc, struct scatterlist *sdst,
+             struct scatterlist *ssrc, unsigned int nbytes,
+             struct xts_crypt_req *req)
+{
+       const unsigned int bsize = XTS_BLOCK_SIZE;
+       const unsigned int max_blks = req->tbuflen / bsize;
+       struct blkcipher_walk walk;
+       unsigned int nblocks;
+       be128 *src, *dst, *t;
+       be128 *t_buf = req->tbuf;
+       int err, i;
+
+       BUG_ON(max_blks < 1);
+
+       blkcipher_walk_init(&walk, sdst, ssrc, nbytes);
+
+       err = blkcipher_walk_virt(desc, &walk);
+       nbytes = walk.nbytes;
+       if (!nbytes)
+               return err;
+
+       nblocks = min(nbytes / bsize, max_blks);
+       src = (be128 *)walk.src.virt.addr;
+       dst = (be128 *)walk.dst.virt.addr;
+
+       /* calculate first value of T */
+       req->tweak_fn(req->tweak_ctx, (u8 *)&t_buf[0], walk.iv);
+
+       i = 0;
+       goto first;
+
+       for (;;) {
+               do {
+                       for (i = 0; i < nblocks; i++) {
+                               gf128mul_x_ble(&t_buf[i], t);
+first:
+                               t = &t_buf[i];
+
+                               /* PP <- T xor P */
+                               be128_xor(dst + i, t, src + i);
+                       }
+
+                       /* CC <- E(Key2,PP) */
+                       req->crypt_fn(req->crypt_ctx, (u8 *)dst,
+                                     nblocks * bsize);
+
+                       /* C <- T xor CC */
+                       for (i = 0; i < nblocks; i++)
+                               be128_xor(dst + i, dst + i, &t_buf[i]);
+
+                       src += nblocks;
+                       dst += nblocks;
+                       nbytes -= nblocks * bsize;
+                       nblocks = min(nbytes / bsize, max_blks);
+               } while (nblocks > 0);
+
+               *(be128 *)walk.iv = *t;
+
+               err = blkcipher_walk_done(desc, &walk, nbytes);
+               nbytes = walk.nbytes;
+               if (!nbytes)
+                       break;
+
+               nblocks = min(nbytes / bsize, max_blks);
+               src = (be128 *)walk.src.virt.addr;
+               dst = (be128 *)walk.dst.virt.addr;
+       }
+
+       return err;
+}
+EXPORT_SYMBOL_GPL(xts_crypt);
+
 static int init_tfm(struct crypto_tfm *tfm)
 {
        struct crypto_cipher *cipher;
@@ -177,7 +250,7 @@ static int init_tfm(struct crypto_tfm *tfm)
        if (IS_ERR(cipher))
                return PTR_ERR(cipher);
 
-       if (crypto_cipher_blocksize(cipher) != 16) {
+       if (crypto_cipher_blocksize(cipher) != XTS_BLOCK_SIZE) {
                *flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
                crypto_free_cipher(cipher);
                return -EINVAL;
@@ -192,7 +265,7 @@ static int init_tfm(struct crypto_tfm *tfm)
        }
 
        /* this check isn't really needed, leave it here just in case */
-       if (crypto_cipher_blocksize(cipher) != 16) {
+       if (crypto_cipher_blocksize(cipher) != XTS_BLOCK_SIZE) {
                crypto_free_cipher(cipher);
                crypto_free_cipher(ctx->child);
                *flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;