[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 <herbert@gondor.apana.org.au>
This commit is contained in:
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50b6544e13
commit
d0b9007a27
105
crypto/pcbc.c
105
crypto/pcbc.c
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@ -24,7 +24,6 @@
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struct crypto_pcbc_ctx {
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struct crypto_cipher *child;
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void (*xor)(u8 *dst, const u8 *src, unsigned int bs);
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};
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static int crypto_pcbc_setkey(struct crypto_tfm *parent, const u8 *key,
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@ -45,9 +44,7 @@ static int crypto_pcbc_setkey(struct crypto_tfm *parent, const u8 *key,
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static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc,
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struct blkcipher_walk *walk,
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struct crypto_cipher *tfm,
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void (*xor)(u8 *, const u8 *,
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unsigned int))
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struct crypto_cipher *tfm)
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{
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void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
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crypto_cipher_alg(tfm)->cia_encrypt;
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@ -58,10 +55,10 @@ static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc,
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u8 *iv = walk->iv;
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do {
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xor(iv, src, bsize);
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crypto_xor(iv, src, bsize);
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fn(crypto_cipher_tfm(tfm), dst, iv);
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memcpy(iv, dst, bsize);
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xor(iv, src, bsize);
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crypto_xor(iv, src, bsize);
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src += bsize;
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dst += bsize;
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@ -72,9 +69,7 @@ static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc,
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static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc,
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struct blkcipher_walk *walk,
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struct crypto_cipher *tfm,
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void (*xor)(u8 *, const u8 *,
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unsigned int))
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struct crypto_cipher *tfm)
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{
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void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
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crypto_cipher_alg(tfm)->cia_encrypt;
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@ -86,10 +81,10 @@ static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc,
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do {
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memcpy(tmpbuf, src, bsize);
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xor(iv, tmpbuf, bsize);
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crypto_xor(iv, src, bsize);
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fn(crypto_cipher_tfm(tfm), src, iv);
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memcpy(iv, src, bsize);
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xor(iv, tmpbuf, bsize);
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memcpy(iv, tmpbuf, bsize);
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crypto_xor(iv, src, bsize);
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src += bsize;
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} while ((nbytes -= bsize) >= bsize);
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@ -107,7 +102,6 @@ static int crypto_pcbc_encrypt(struct blkcipher_desc *desc,
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struct crypto_blkcipher *tfm = desc->tfm;
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struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
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struct crypto_cipher *child = ctx->child;
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void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor;
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int err;
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blkcipher_walk_init(&walk, dst, src, nbytes);
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@ -115,11 +109,11 @@ static int crypto_pcbc_encrypt(struct blkcipher_desc *desc,
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while ((nbytes = walk.nbytes)) {
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if (walk.src.virt.addr == walk.dst.virt.addr)
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nbytes = crypto_pcbc_encrypt_inplace(desc, &walk, child,
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xor);
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nbytes = crypto_pcbc_encrypt_inplace(desc, &walk,
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child);
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else
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nbytes = crypto_pcbc_encrypt_segment(desc, &walk, child,
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xor);
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nbytes = crypto_pcbc_encrypt_segment(desc, &walk,
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child);
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err = blkcipher_walk_done(desc, &walk, nbytes);
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}
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@ -128,9 +122,7 @@ static int crypto_pcbc_encrypt(struct blkcipher_desc *desc,
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static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc,
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struct blkcipher_walk *walk,
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struct crypto_cipher *tfm,
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void (*xor)(u8 *, const u8 *,
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unsigned int))
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struct crypto_cipher *tfm)
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{
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void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
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crypto_cipher_alg(tfm)->cia_decrypt;
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@ -142,9 +134,9 @@ static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc,
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do {
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fn(crypto_cipher_tfm(tfm), dst, src);
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xor(dst, iv, bsize);
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crypto_xor(dst, iv, bsize);
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memcpy(iv, src, bsize);
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xor(iv, dst, bsize);
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crypto_xor(iv, dst, bsize);
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src += bsize;
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dst += bsize;
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@ -157,9 +149,7 @@ static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc,
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static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc,
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struct blkcipher_walk *walk,
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struct crypto_cipher *tfm,
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void (*xor)(u8 *, const u8 *,
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unsigned int))
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struct crypto_cipher *tfm)
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{
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void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
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crypto_cipher_alg(tfm)->cia_decrypt;
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@ -172,9 +162,9 @@ static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc,
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do {
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memcpy(tmpbuf, src, bsize);
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fn(crypto_cipher_tfm(tfm), src, src);
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xor(src, iv, bsize);
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crypto_xor(src, iv, bsize);
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memcpy(iv, tmpbuf, bsize);
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xor(iv, src, bsize);
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crypto_xor(iv, src, bsize);
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src += bsize;
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} while ((nbytes -= bsize) >= bsize);
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@ -192,7 +182,6 @@ static int crypto_pcbc_decrypt(struct blkcipher_desc *desc,
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struct crypto_blkcipher *tfm = desc->tfm;
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struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
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struct crypto_cipher *child = ctx->child;
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void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor;
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int err;
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blkcipher_walk_init(&walk, dst, src, nbytes);
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@ -200,48 +189,17 @@ static int crypto_pcbc_decrypt(struct blkcipher_desc *desc,
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while ((nbytes = walk.nbytes)) {
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if (walk.src.virt.addr == walk.dst.virt.addr)
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nbytes = crypto_pcbc_decrypt_inplace(desc, &walk, child,
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xor);
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nbytes = crypto_pcbc_decrypt_inplace(desc, &walk,
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child);
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else
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nbytes = crypto_pcbc_decrypt_segment(desc, &walk, child,
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xor);
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nbytes = crypto_pcbc_decrypt_segment(desc, &walk,
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child);
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err = blkcipher_walk_done(desc, &walk, nbytes);
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}
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return err;
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}
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static void xor_byte(u8 *a, const u8 *b, unsigned int bs)
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{
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do {
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*a++ ^= *b++;
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} while (--bs);
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}
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static void xor_quad(u8 *dst, const u8 *src, unsigned int bs)
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{
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u32 *a = (u32 *)dst;
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u32 *b = (u32 *)src;
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do {
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*a++ ^= *b++;
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} while ((bs -= 4));
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}
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static void xor_64(u8 *a, const u8 *b, unsigned int bs)
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{
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((u32 *)a)[0] ^= ((u32 *)b)[0];
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((u32 *)a)[1] ^= ((u32 *)b)[1];
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}
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static void xor_128(u8 *a, const u8 *b, unsigned int bs)
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{
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((u32 *)a)[0] ^= ((u32 *)b)[0];
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((u32 *)a)[1] ^= ((u32 *)b)[1];
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((u32 *)a)[2] ^= ((u32 *)b)[2];
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((u32 *)a)[3] ^= ((u32 *)b)[3];
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}
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static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm)
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{
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struct crypto_instance *inst = (void *)tfm->__crt_alg;
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@ -249,22 +207,6 @@ static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm)
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struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm);
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struct crypto_cipher *cipher;
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switch (crypto_tfm_alg_blocksize(tfm)) {
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case 8:
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ctx->xor = xor_64;
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break;
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case 16:
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ctx->xor = xor_128;
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break;
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default:
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if (crypto_tfm_alg_blocksize(tfm) % 4)
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ctx->xor = xor_byte;
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else
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ctx->xor = xor_quad;
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}
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cipher = crypto_spawn_cipher(spawn);
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if (IS_ERR(cipher))
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return PTR_ERR(cipher);
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@ -304,8 +246,9 @@ static struct crypto_instance *crypto_pcbc_alloc(struct rtattr **tb)
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inst->alg.cra_alignmask = alg->cra_alignmask;
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inst->alg.cra_type = &crypto_blkcipher_type;
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if (!(alg->cra_blocksize % 4))
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inst->alg.cra_alignmask |= 3;
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/* We access the data as u32s when xoring. */
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inst->alg.cra_alignmask |= __alignof__(u32) - 1;
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inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
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inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
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inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
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