crypto: keywrap - convert to skcipher API
Convert the keywrap template from the deprecated "blkcipher" API to the "skcipher" API, taking advantage of skcipher_alloc_instance_simple() to simplify it considerably. Cc: Stephan Mueller <smueller@chronox.de> Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Eric Biggers
Herbert Xu
parent
52e9368fe6
commit
6b611d98c6
198
crypto/keywrap.c
198
crypto/keywrap.c
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@ -56,7 +56,7 @@
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* u8 *iv = data;
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* u8 *pt = data + crypto_skcipher_ivsize(tfm);
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* <ensure that pt contains the plaintext of size ptlen>
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* sg_init_one(&sg, ptdata, ptlen);
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* sg_init_one(&sg, pt, ptlen);
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* skcipher_request_set_crypt(req, &sg, &sg, ptlen, iv);
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*
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* ==> After encryption, data now contains full KW result as per SP800-38F.
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@ -70,8 +70,8 @@
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* u8 *iv = data;
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* u8 *ct = data + crypto_skcipher_ivsize(tfm);
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* unsigned int ctlen = datalen - crypto_skcipher_ivsize(tfm);
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* sg_init_one(&sg, ctdata, ctlen);
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* skcipher_request_set_crypt(req, &sg, &sg, ptlen, iv);
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* sg_init_one(&sg, ct, ctlen);
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* skcipher_request_set_crypt(req, &sg, &sg, ctlen, iv);
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*
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* ==> After decryption (which hopefully does not return EBADMSG), the ct
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* pointer now points to the plaintext of size ctlen.
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@ -87,10 +87,6 @@
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#include <crypto/scatterwalk.h>
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#include <crypto/internal/skcipher.h>
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struct crypto_kw_ctx {
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struct crypto_cipher *child;
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};
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struct crypto_kw_block {
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#define SEMIBSIZE 8
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__be64 A;
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@ -124,16 +120,13 @@ static void crypto_kw_scatterlist_ff(struct scatter_walk *walk,
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}
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}
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static int crypto_kw_decrypt(struct blkcipher_desc *desc,
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struct scatterlist *dst, struct scatterlist *src,
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unsigned int nbytes)
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static int crypto_kw_decrypt(struct skcipher_request *req)
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{
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struct crypto_blkcipher *tfm = desc->tfm;
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struct crypto_kw_ctx *ctx = crypto_blkcipher_ctx(tfm);
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struct crypto_cipher *child = ctx->child;
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
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struct crypto_kw_block block;
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struct scatterlist *lsrc, *ldst;
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u64 t = 6 * ((nbytes) >> 3);
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struct scatterlist *src, *dst;
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u64 t = 6 * ((req->cryptlen) >> 3);
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unsigned int i;
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int ret = 0;
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@ -141,27 +134,27 @@ static int crypto_kw_decrypt(struct blkcipher_desc *desc,
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* Require at least 2 semiblocks (note, the 3rd semiblock that is
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* required by SP800-38F is the IV.
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*/
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if (nbytes < (2 * SEMIBSIZE) || nbytes % SEMIBSIZE)
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if (req->cryptlen < (2 * SEMIBSIZE) || req->cryptlen % SEMIBSIZE)
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return -EINVAL;
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/* Place the IV into block A */
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memcpy(&block.A, desc->info, SEMIBSIZE);
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memcpy(&block.A, req->iv, SEMIBSIZE);
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/*
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* src scatterlist is read-only. dst scatterlist is r/w. During the
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* first loop, lsrc points to src and ldst to dst. For any
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* subsequent round, the code operates on dst only.
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* first loop, src points to req->src and dst to req->dst. For any
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* subsequent round, the code operates on req->dst only.
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*/
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lsrc = src;
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ldst = dst;
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src = req->src;
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dst = req->dst;
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for (i = 0; i < 6; i++) {
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struct scatter_walk src_walk, dst_walk;
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unsigned int tmp_nbytes = nbytes;
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unsigned int nbytes = req->cryptlen;
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while (tmp_nbytes) {
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/* move pointer by tmp_nbytes in the SGL */
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crypto_kw_scatterlist_ff(&src_walk, lsrc, tmp_nbytes);
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while (nbytes) {
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/* move pointer by nbytes in the SGL */
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crypto_kw_scatterlist_ff(&src_walk, src, nbytes);
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/* get the source block */
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scatterwalk_copychunks(&block.R, &src_walk, SEMIBSIZE,
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false);
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@ -170,21 +163,21 @@ static int crypto_kw_decrypt(struct blkcipher_desc *desc,
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block.A ^= cpu_to_be64(t);
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t--;
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/* perform KW operation: decrypt block */
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crypto_cipher_decrypt_one(child, (u8*)&block,
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(u8*)&block);
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crypto_cipher_decrypt_one(cipher, (u8 *)&block,
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(u8 *)&block);
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/* move pointer by tmp_nbytes in the SGL */
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crypto_kw_scatterlist_ff(&dst_walk, ldst, tmp_nbytes);
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/* move pointer by nbytes in the SGL */
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crypto_kw_scatterlist_ff(&dst_walk, dst, nbytes);
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/* Copy block->R into place */
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scatterwalk_copychunks(&block.R, &dst_walk, SEMIBSIZE,
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true);
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tmp_nbytes -= SEMIBSIZE;
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nbytes -= SEMIBSIZE;
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}
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/* we now start to operate on the dst SGL only */
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lsrc = dst;
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ldst = dst;
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src = req->dst;
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dst = req->dst;
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}
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/* Perform authentication check */
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@ -196,15 +189,12 @@ static int crypto_kw_decrypt(struct blkcipher_desc *desc,
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return ret;
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}
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static int crypto_kw_encrypt(struct blkcipher_desc *desc,
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struct scatterlist *dst, struct scatterlist *src,
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unsigned int nbytes)
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static int crypto_kw_encrypt(struct skcipher_request *req)
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{
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struct crypto_blkcipher *tfm = desc->tfm;
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struct crypto_kw_ctx *ctx = crypto_blkcipher_ctx(tfm);
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struct crypto_cipher *child = ctx->child;
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
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struct crypto_kw_block block;
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struct scatterlist *lsrc, *ldst;
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struct scatterlist *src, *dst;
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u64 t = 1;
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unsigned int i;
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@ -214,7 +204,7 @@ static int crypto_kw_encrypt(struct blkcipher_desc *desc,
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* This means that the dst memory must be one semiblock larger than src.
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* Also ensure that the given data is aligned to semiblock.
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*/
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if (nbytes < (2 * SEMIBSIZE) || nbytes % SEMIBSIZE)
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if (req->cryptlen < (2 * SEMIBSIZE) || req->cryptlen % SEMIBSIZE)
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return -EINVAL;
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/*
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@ -225,26 +215,26 @@ static int crypto_kw_encrypt(struct blkcipher_desc *desc,
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/*
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* src scatterlist is read-only. dst scatterlist is r/w. During the
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* first loop, lsrc points to src and ldst to dst. For any
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* subsequent round, the code operates on dst only.
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* first loop, src points to req->src and dst to req->dst. For any
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* subsequent round, the code operates on req->dst only.
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*/
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lsrc = src;
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ldst = dst;
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src = req->src;
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dst = req->dst;
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for (i = 0; i < 6; i++) {
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struct scatter_walk src_walk, dst_walk;
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unsigned int tmp_nbytes = nbytes;
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unsigned int nbytes = req->cryptlen;
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scatterwalk_start(&src_walk, lsrc);
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scatterwalk_start(&dst_walk, ldst);
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scatterwalk_start(&src_walk, src);
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scatterwalk_start(&dst_walk, dst);
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while (tmp_nbytes) {
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while (nbytes) {
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/* get the source block */
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scatterwalk_copychunks(&block.R, &src_walk, SEMIBSIZE,
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false);
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/* perform KW operation: encrypt block */
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crypto_cipher_encrypt_one(child, (u8 *)&block,
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crypto_cipher_encrypt_one(cipher, (u8 *)&block,
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(u8 *)&block);
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/* perform KW operation: modify IV with counter */
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block.A ^= cpu_to_be64(t);
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@ -254,117 +244,59 @@ static int crypto_kw_encrypt(struct blkcipher_desc *desc,
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scatterwalk_copychunks(&block.R, &dst_walk, SEMIBSIZE,
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true);
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tmp_nbytes -= SEMIBSIZE;
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nbytes -= SEMIBSIZE;
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}
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/* we now start to operate on the dst SGL only */
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lsrc = dst;
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ldst = dst;
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src = req->dst;
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dst = req->dst;
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}
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/* establish the IV for the caller to pick up */
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memcpy(desc->info, &block.A, SEMIBSIZE);
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memcpy(req->iv, &block.A, SEMIBSIZE);
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memzero_explicit(&block, sizeof(struct crypto_kw_block));
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return 0;
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}
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static int crypto_kw_setkey(struct crypto_tfm *parent, const u8 *key,
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unsigned int keylen)
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static int crypto_kw_create(struct crypto_template *tmpl, struct rtattr **tb)
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{
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struct crypto_kw_ctx *ctx = crypto_tfm_ctx(parent);
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struct crypto_cipher *child = ctx->child;
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struct skcipher_instance *inst;
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struct crypto_alg *alg;
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int err;
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crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
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crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
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CRYPTO_TFM_REQ_MASK);
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err = crypto_cipher_setkey(child, key, keylen);
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crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
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CRYPTO_TFM_RES_MASK);
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return err;
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}
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inst = skcipher_alloc_instance_simple(tmpl, tb, &alg);
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if (IS_ERR(inst))
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return PTR_ERR(inst);
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static int crypto_kw_init_tfm(struct crypto_tfm *tfm)
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{
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struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
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struct crypto_spawn *spawn = crypto_instance_ctx(inst);
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struct crypto_kw_ctx *ctx = crypto_tfm_ctx(tfm);
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struct crypto_cipher *cipher;
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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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ctx->child = cipher;
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return 0;
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}
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static void crypto_kw_exit_tfm(struct crypto_tfm *tfm)
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{
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struct crypto_kw_ctx *ctx = crypto_tfm_ctx(tfm);
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crypto_free_cipher(ctx->child);
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}
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static struct crypto_instance *crypto_kw_alloc(struct rtattr **tb)
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{
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struct crypto_instance *inst = NULL;
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struct crypto_alg *alg = NULL;
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int err;
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err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
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if (err)
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return ERR_PTR(err);
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alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
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CRYPTO_ALG_TYPE_MASK);
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if (IS_ERR(alg))
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return ERR_CAST(alg);
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inst = ERR_PTR(-EINVAL);
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err = -EINVAL;
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/* Section 5.1 requirement for KW */
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if (alg->cra_blocksize != sizeof(struct crypto_kw_block))
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goto err;
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goto out_free_inst;
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inst = crypto_alloc_instance("kw", alg);
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if (IS_ERR(inst))
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goto err;
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inst->alg.base.cra_blocksize = SEMIBSIZE;
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inst->alg.base.cra_alignmask = 0;
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inst->alg.ivsize = SEMIBSIZE;
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inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
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inst->alg.cra_priority = alg->cra_priority;
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inst->alg.cra_blocksize = SEMIBSIZE;
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inst->alg.cra_alignmask = 0;
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inst->alg.cra_type = &crypto_blkcipher_type;
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inst->alg.cra_blkcipher.ivsize = SEMIBSIZE;
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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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inst->alg.encrypt = crypto_kw_encrypt;
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inst->alg.decrypt = crypto_kw_decrypt;
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inst->alg.cra_ctxsize = sizeof(struct crypto_kw_ctx);
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err = skcipher_register_instance(tmpl, inst);
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if (err)
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goto out_free_inst;
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goto out_put_alg;
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inst->alg.cra_init = crypto_kw_init_tfm;
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inst->alg.cra_exit = crypto_kw_exit_tfm;
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inst->alg.cra_blkcipher.setkey = crypto_kw_setkey;
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inst->alg.cra_blkcipher.encrypt = crypto_kw_encrypt;
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inst->alg.cra_blkcipher.decrypt = crypto_kw_decrypt;
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err:
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out_free_inst:
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inst->free(inst);
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out_put_alg:
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crypto_mod_put(alg);
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return inst;
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}
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static void crypto_kw_free(struct crypto_instance *inst)
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{
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crypto_drop_spawn(crypto_instance_ctx(inst));
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kfree(inst);
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return err;
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}
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static struct crypto_template crypto_kw_tmpl = {
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.name = "kw",
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.alloc = crypto_kw_alloc,
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.free = crypto_kw_free,
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.create = crypto_kw_create,
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.module = THIS_MODULE,
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};
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