From 6b611d98c6f5c5a328f1698c4cad7447544a5da7 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 3 Jan 2019 20:16:19 -0800 Subject: [PATCH] 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 Signed-off-by: Eric Biggers Reviewed-by: Stephan Mueller Signed-off-by: Herbert Xu --- crypto/keywrap.c | 198 ++++++++++++++++------------------------------- 1 file changed, 65 insertions(+), 133 deletions(-) diff --git a/crypto/keywrap.c b/crypto/keywrap.c index ec5c6a087c90..a5cfe610d8f4 100644 --- a/crypto/keywrap.c +++ b/crypto/keywrap.c @@ -56,7 +56,7 @@ * u8 *iv = data; * u8 *pt = data + crypto_skcipher_ivsize(tfm); * - * sg_init_one(&sg, ptdata, ptlen); + * sg_init_one(&sg, pt, ptlen); * skcipher_request_set_crypt(req, &sg, &sg, ptlen, iv); * * ==> After encryption, data now contains full KW result as per SP800-38F. @@ -70,8 +70,8 @@ * u8 *iv = data; * u8 *ct = data + crypto_skcipher_ivsize(tfm); * unsigned int ctlen = datalen - crypto_skcipher_ivsize(tfm); - * sg_init_one(&sg, ctdata, ctlen); - * skcipher_request_set_crypt(req, &sg, &sg, ptlen, iv); + * sg_init_one(&sg, ct, ctlen); + * skcipher_request_set_crypt(req, &sg, &sg, ctlen, iv); * * ==> After decryption (which hopefully does not return EBADMSG), the ct * pointer now points to the plaintext of size ctlen. @@ -87,10 +87,6 @@ #include #include -struct crypto_kw_ctx { - struct crypto_cipher *child; -}; - struct crypto_kw_block { #define SEMIBSIZE 8 __be64 A; @@ -124,16 +120,13 @@ static void crypto_kw_scatterlist_ff(struct scatter_walk *walk, } } -static int crypto_kw_decrypt(struct blkcipher_desc *desc, - struct scatterlist *dst, struct scatterlist *src, - unsigned int nbytes) +static int crypto_kw_decrypt(struct skcipher_request *req) { - struct crypto_blkcipher *tfm = desc->tfm; - struct crypto_kw_ctx *ctx = crypto_blkcipher_ctx(tfm); - struct crypto_cipher *child = ctx->child; + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_cipher *cipher = skcipher_cipher_simple(tfm); struct crypto_kw_block block; - struct scatterlist *lsrc, *ldst; - u64 t = 6 * ((nbytes) >> 3); + struct scatterlist *src, *dst; + u64 t = 6 * ((req->cryptlen) >> 3); unsigned int i; int ret = 0; @@ -141,27 +134,27 @@ static int crypto_kw_decrypt(struct blkcipher_desc *desc, * Require at least 2 semiblocks (note, the 3rd semiblock that is * required by SP800-38F is the IV. */ - if (nbytes < (2 * SEMIBSIZE) || nbytes % SEMIBSIZE) + if (req->cryptlen < (2 * SEMIBSIZE) || req->cryptlen % SEMIBSIZE) return -EINVAL; /* Place the IV into block A */ - memcpy(&block.A, desc->info, SEMIBSIZE); + memcpy(&block.A, req->iv, SEMIBSIZE); /* * src scatterlist is read-only. dst scatterlist is r/w. During the - * first loop, lsrc points to src and ldst to dst. For any - * subsequent round, the code operates on dst only. + * first loop, src points to req->src and dst to req->dst. For any + * subsequent round, the code operates on req->dst only. */ - lsrc = src; - ldst = dst; + src = req->src; + dst = req->dst; for (i = 0; i < 6; i++) { struct scatter_walk src_walk, dst_walk; - unsigned int tmp_nbytes = nbytes; + unsigned int nbytes = req->cryptlen; - while (tmp_nbytes) { - /* move pointer by tmp_nbytes in the SGL */ - crypto_kw_scatterlist_ff(&src_walk, lsrc, tmp_nbytes); + while (nbytes) { + /* move pointer by nbytes in the SGL */ + crypto_kw_scatterlist_ff(&src_walk, src, nbytes); /* get the source block */ scatterwalk_copychunks(&block.R, &src_walk, SEMIBSIZE, false); @@ -170,21 +163,21 @@ static int crypto_kw_decrypt(struct blkcipher_desc *desc, block.A ^= cpu_to_be64(t); t--; /* perform KW operation: decrypt block */ - crypto_cipher_decrypt_one(child, (u8*)&block, - (u8*)&block); + crypto_cipher_decrypt_one(cipher, (u8 *)&block, + (u8 *)&block); - /* move pointer by tmp_nbytes in the SGL */ - crypto_kw_scatterlist_ff(&dst_walk, ldst, tmp_nbytes); + /* move pointer by nbytes in the SGL */ + crypto_kw_scatterlist_ff(&dst_walk, dst, nbytes); /* Copy block->R into place */ scatterwalk_copychunks(&block.R, &dst_walk, SEMIBSIZE, true); - tmp_nbytes -= SEMIBSIZE; + nbytes -= SEMIBSIZE; } /* we now start to operate on the dst SGL only */ - lsrc = dst; - ldst = dst; + src = req->dst; + dst = req->dst; } /* Perform authentication check */ @@ -196,15 +189,12 @@ static int crypto_kw_decrypt(struct blkcipher_desc *desc, return ret; } -static int crypto_kw_encrypt(struct blkcipher_desc *desc, - struct scatterlist *dst, struct scatterlist *src, - unsigned int nbytes) +static int crypto_kw_encrypt(struct skcipher_request *req) { - struct crypto_blkcipher *tfm = desc->tfm; - struct crypto_kw_ctx *ctx = crypto_blkcipher_ctx(tfm); - struct crypto_cipher *child = ctx->child; + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_cipher *cipher = skcipher_cipher_simple(tfm); struct crypto_kw_block block; - struct scatterlist *lsrc, *ldst; + struct scatterlist *src, *dst; u64 t = 1; unsigned int i; @@ -214,7 +204,7 @@ static int crypto_kw_encrypt(struct blkcipher_desc *desc, * This means that the dst memory must be one semiblock larger than src. * Also ensure that the given data is aligned to semiblock. */ - if (nbytes < (2 * SEMIBSIZE) || nbytes % SEMIBSIZE) + if (req->cryptlen < (2 * SEMIBSIZE) || req->cryptlen % SEMIBSIZE) return -EINVAL; /* @@ -225,26 +215,26 @@ static int crypto_kw_encrypt(struct blkcipher_desc *desc, /* * src scatterlist is read-only. dst scatterlist is r/w. During the - * first loop, lsrc points to src and ldst to dst. For any - * subsequent round, the code operates on dst only. + * first loop, src points to req->src and dst to req->dst. For any + * subsequent round, the code operates on req->dst only. */ - lsrc = src; - ldst = dst; + src = req->src; + dst = req->dst; for (i = 0; i < 6; i++) { struct scatter_walk src_walk, dst_walk; - unsigned int tmp_nbytes = nbytes; + unsigned int nbytes = req->cryptlen; - scatterwalk_start(&src_walk, lsrc); - scatterwalk_start(&dst_walk, ldst); + scatterwalk_start(&src_walk, src); + scatterwalk_start(&dst_walk, dst); - while (tmp_nbytes) { + while (nbytes) { /* get the source block */ scatterwalk_copychunks(&block.R, &src_walk, SEMIBSIZE, false); /* perform KW operation: encrypt block */ - crypto_cipher_encrypt_one(child, (u8 *)&block, + crypto_cipher_encrypt_one(cipher, (u8 *)&block, (u8 *)&block); /* perform KW operation: modify IV with counter */ block.A ^= cpu_to_be64(t); @@ -254,117 +244,59 @@ static int crypto_kw_encrypt(struct blkcipher_desc *desc, scatterwalk_copychunks(&block.R, &dst_walk, SEMIBSIZE, true); - tmp_nbytes -= SEMIBSIZE; + nbytes -= SEMIBSIZE; } /* we now start to operate on the dst SGL only */ - lsrc = dst; - ldst = dst; + src = req->dst; + dst = req->dst; } /* establish the IV for the caller to pick up */ - memcpy(desc->info, &block.A, SEMIBSIZE); + memcpy(req->iv, &block.A, SEMIBSIZE); memzero_explicit(&block, sizeof(struct crypto_kw_block)); return 0; } -static int crypto_kw_setkey(struct crypto_tfm *parent, const u8 *key, - unsigned int keylen) +static int crypto_kw_create(struct crypto_template *tmpl, struct rtattr **tb) { - struct crypto_kw_ctx *ctx = crypto_tfm_ctx(parent); - struct crypto_cipher *child = ctx->child; + struct skcipher_instance *inst; + struct crypto_alg *alg; int err; - crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK); - crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) & - CRYPTO_TFM_REQ_MASK); - err = crypto_cipher_setkey(child, key, keylen); - crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) & - CRYPTO_TFM_RES_MASK); - return err; -} - -static int crypto_kw_init_tfm(struct crypto_tfm *tfm) -{ - struct crypto_instance *inst = crypto_tfm_alg_instance(tfm); - struct crypto_spawn *spawn = crypto_instance_ctx(inst); - struct crypto_kw_ctx *ctx = crypto_tfm_ctx(tfm); - struct crypto_cipher *cipher; - - cipher = crypto_spawn_cipher(spawn); - if (IS_ERR(cipher)) - return PTR_ERR(cipher); - - ctx->child = cipher; - return 0; -} - -static void crypto_kw_exit_tfm(struct crypto_tfm *tfm) -{ - struct crypto_kw_ctx *ctx = crypto_tfm_ctx(tfm); - - crypto_free_cipher(ctx->child); -} - -static struct crypto_instance *crypto_kw_alloc(struct rtattr **tb) -{ - struct crypto_instance *inst = NULL; - struct crypto_alg *alg = NULL; - int err; - - err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER); - if (err) - return ERR_PTR(err); - - alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, - CRYPTO_ALG_TYPE_MASK); - if (IS_ERR(alg)) - return ERR_CAST(alg); + inst = skcipher_alloc_instance_simple(tmpl, tb, &alg); + if (IS_ERR(inst)) + return PTR_ERR(inst); - inst = ERR_PTR(-EINVAL); + err = -EINVAL; /* Section 5.1 requirement for KW */ if (alg->cra_blocksize != sizeof(struct crypto_kw_block)) - goto err; + goto out_free_inst; - inst = crypto_alloc_instance("kw", alg); - if (IS_ERR(inst)) - goto err; + inst->alg.base.cra_blocksize = SEMIBSIZE; + inst->alg.base.cra_alignmask = 0; + inst->alg.ivsize = SEMIBSIZE; - inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER; - inst->alg.cra_priority = alg->cra_priority; - inst->alg.cra_blocksize = SEMIBSIZE; - inst->alg.cra_alignmask = 0; - inst->alg.cra_type = &crypto_blkcipher_type; - inst->alg.cra_blkcipher.ivsize = SEMIBSIZE; - inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize; - inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize; + inst->alg.encrypt = crypto_kw_encrypt; + inst->alg.decrypt = crypto_kw_decrypt; - inst->alg.cra_ctxsize = sizeof(struct crypto_kw_ctx); - - inst->alg.cra_init = crypto_kw_init_tfm; - inst->alg.cra_exit = crypto_kw_exit_tfm; - - inst->alg.cra_blkcipher.setkey = crypto_kw_setkey; - inst->alg.cra_blkcipher.encrypt = crypto_kw_encrypt; - inst->alg.cra_blkcipher.decrypt = crypto_kw_decrypt; + err = skcipher_register_instance(tmpl, inst); + if (err) + goto out_free_inst; + goto out_put_alg; -err: +out_free_inst: + inst->free(inst); +out_put_alg: crypto_mod_put(alg); - return inst; -} - -static void crypto_kw_free(struct crypto_instance *inst) -{ - crypto_drop_spawn(crypto_instance_ctx(inst)); - kfree(inst); + return err; } static struct crypto_template crypto_kw_tmpl = { .name = "kw", - .alloc = crypto_kw_alloc, - .free = crypto_kw_free, + .create = crypto_kw_create, .module = THIS_MODULE, }; -- 2.30.2