litmus-rt.git - The LITMUS^RT kernel.

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author	Mike Turquette <mturquette@linaro.org>	2013-12-20 15:53:02 -0500
committer	Mike Turquette <mturquette@linaro.org>	2013-12-20 15:53:02 -0500
commit	7cba64cd901b21c6c162f8dce4353acec29ae2a8 (patch)
tree	b2f86681050be4395efc4d5edb51c386d21196cb /drivers/usb/gadget/f_ecm.c
parent	24c039f6acacd63e739b39a030197d5a2945e0d2 (diff)
parent	ba52f8a986089e263ea28e231b6a405769ae1235 (diff)

Merge tag 'zynq-clk-for-3.14-v2' of git://git.xilinx.com/linux-xlnx into clk-next

arm: Xilinx Zynq clk patches for v3.14 - Add support for fclk-enable feature

Diffstat (limited to 'drivers/usb/gadget/f_ecm.c')

0 files changed, 0 insertions, 0 deletions

//SPDX-License-Identifier: GPL-2.0 /* * CFB: Cipher FeedBack mode * * Copyright (c) 2018 James.Bottomley@HansenPartnership.com * * CFB is a stream cipher mode which is layered on to a block * encryption scheme. It works very much like a one time pad where * the pad is generated initially from the encrypted IV and then * subsequently from the encrypted previous block of ciphertext. The * pad is XOR'd into the plain text to get the final ciphertext. * * The scheme of CFB is best described by wikipedia: * * https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#CFB * * Note that since the pad for both encryption and decryption is * generated by an encryption operation, CFB never uses the block * decryption function. */ #include <crypto/algapi.h> #include <crypto/internal/skcipher.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/types.h> struct crypto_cfb_ctx { struct crypto_cipher *child; }; static unsigned int crypto_cfb_bsize(struct crypto_skcipher *tfm) { struct crypto_cfb_ctx *ctx = crypto_skcipher_ctx(tfm); struct crypto_cipher *child = ctx->child; return crypto_cipher_blocksize(child); } static void crypto_cfb_encrypt_one(struct crypto_skcipher *tfm, const u8 *src, u8 *dst) { struct crypto_cfb_ctx *ctx = crypto_skcipher_ctx(tfm); crypto_cipher_encrypt_one(ctx->child, dst, src); } /* final encrypt and decrypt is the same */ static void crypto_cfb_final(struct skcipher_walk *walk, struct crypto_skcipher *tfm) { const unsigned long alignmask = crypto_skcipher_alignmask(tfm); u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK]; u8 *stream = PTR_ALIGN(tmp + 0, alignmask + 1); u8 *src = walk->src.virt.addr; u8 *dst = walk->dst.virt.addr; u8 *iv = walk->iv; unsigned int nbytes = walk->nbytes; crypto_cfb_encrypt_one(tfm, iv, stream); crypto_xor_cpy(dst, stream, src, nbytes); } static int crypto_cfb_encrypt_segment(struct skcipher_walk *walk, struct crypto_skcipher *tfm) { const unsigned int bsize = crypto_cfb_bsize(tfm); unsigned int nbytes = walk->nbytes; u8 *src = walk->src.virt.addr; u8 *dst = walk->dst.virt.addr; u8 *iv = walk->iv; do { crypto_cfb_encrypt_one(tfm, iv, dst); crypto_xor(dst, src, bsize); memcpy(iv, dst, bsize); src += bsize; dst += bsize; } while ((nbytes -= bsize) >= bsize); return nbytes; } static int crypto_cfb_encrypt_inplace(struct skcipher_walk *walk, struct crypto_skcipher *tfm) { const unsigned int bsize = crypto_cfb_bsize(tfm); unsigned int nbytes = walk->nbytes; u8 *src = walk->src.virt.addr; u8 *iv = walk->iv; u8 tmp[MAX_CIPHER_BLOCKSIZE]; do { crypto_cfb_encrypt_one(tfm, iv, tmp); crypto_xor(src, tmp, bsize); iv = src; src += bsize; } while ((nbytes -= bsize) >= bsize); memcpy(walk->iv, iv, bsize); return nbytes; } static int crypto_cfb_encrypt(struct skcipher_request *req) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct skcipher_walk walk; unsigned int bsize = crypto_cfb_bsize(tfm); int err; err = skcipher_walk_virt(&walk, req, false); while (walk.nbytes >= bsize) { if (walk.src.virt.addr == walk.dst.virt.addr) err = crypto_cfb_encrypt_inplace(&walk, tfm); else err = crypto_cfb_encrypt_segment(&walk, tfm); err = skcipher_walk_done(&walk, err); } if (walk.nbytes) { crypto_cfb_final(&walk, tfm); err = skcipher_walk_done(&walk, 0); } return err; } static int crypto_cfb_decrypt_segment(struct skcipher_walk *walk, struct crypto_skcipher *tfm) { const unsigned int bsize = crypto_cfb_bsize(tfm); unsigned int nbytes = walk->nbytes; u8 *src = walk->src.virt.addr; u8 *dst = walk->dst.virt.addr; u8 *iv = walk->iv; do { crypto_cfb_encrypt_one(tfm, iv, dst); crypto_xor(dst, iv, bsize); iv = src; src += bsize; dst += bsize; } while ((nbytes -= bsize) >= bsize); memcpy(walk->iv, iv, bsize); return nbytes; } static int crypto_cfb_decrypt_inplace(struct skcipher_walk *walk, struct crypto_skcipher *tfm) { const unsigned int bsize = crypto_cfb_bsize(tfm); unsigned int nbytes = walk->nbytes; u8 *src = walk->src.virt.addr; u8 *iv = walk->iv; u8 tmp[MAX_CIPHER_BLOCKSIZE]; do { crypto_cfb_encrypt_one(tfm, iv, tmp); memcpy(iv, src, bsize); crypto_xor(src, tmp, bsize); src += bsize; } while ((nbytes -= bsize) >= bsize); memcpy(walk->iv, iv, bsize); return nbytes; } static int crypto_cfb_decrypt_blocks(struct skcipher_walk *walk, struct crypto_skcipher *tfm) { if (walk->src.virt.addr == walk->dst.virt.addr) return crypto_cfb_decrypt_inplace(walk, tfm); else return crypto_cfb_decrypt_segment(walk, tfm); } static int crypto_cfb_setkey(struct crypto_skcipher *parent, const u8 *key, unsigned int keylen) { struct crypto_cfb_ctx *ctx = crypto_skcipher_ctx(parent); struct crypto_cipher *child = ctx->child; int err; crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK); crypto_cipher_set_flags(child, crypto_skcipher_get_flags(parent) & CRYPTO_TFM_REQ_MASK); err = crypto_cipher_setkey(child, key, keylen); crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(child) & CRYPTO_TFM_RES_MASK); return err; } static int crypto_cfb_decrypt(struct skcipher_request *req) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct skcipher_walk walk; const unsigned int bsize = crypto_cfb_bsize(tfm); int err; err = skcipher_walk_virt(&walk, req, false); while (walk.nbytes >= bsize) { err = crypto_cfb_decrypt_blocks(&walk, tfm); err = skcipher_walk_done(&walk, err); } if (walk.nbytes) { crypto_cfb_final(&walk, tfm); err = skcipher_walk_done(&walk, 0); } return err; } static int crypto_cfb_init_tfm(struct crypto_skcipher *tfm) { struct skcipher_instance *inst = skcipher_alg_instance(tfm); struct crypto_spawn *spawn = skcipher_instance_ctx(inst); struct crypto_cfb_ctx *ctx = crypto_skcipher_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_cfb_exit_tfm(struct crypto_skcipher *tfm) { struct crypto_cfb_ctx *ctx = crypto_skcipher_ctx(tfm); crypto_free_cipher(ctx->child); } static void crypto_cfb_free(struct skcipher_instance *inst) { crypto_drop_skcipher(skcipher_instance_ctx(inst)); kfree(inst); } static int crypto_cfb_create(struct crypto_template *tmpl, struct rtattr **tb) { struct skcipher_instance *inst; struct crypto_attr_type *algt; struct crypto_spawn *spawn; struct crypto_alg *alg; u32 mask; int err; err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER); if (err) return err; inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); if (!inst) return -ENOMEM; algt = crypto_get_attr_type(tb); err = PTR_ERR(algt); if (IS_ERR(algt)) goto err_free_inst; mask = CRYPTO_ALG_TYPE_MASK | crypto_requires_off(algt->type, algt->mask, CRYPTO_ALG_NEED_FALLBACK); alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, mask); err = PTR_ERR(alg); if (IS_ERR(alg)) goto err_free_inst; spawn = skcipher_instance_ctx(inst); err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst), CRYPTO_ALG_TYPE_MASK); crypto_mod_put(alg); if (err) goto err_free_inst; err = crypto_inst_setname(skcipher_crypto_instance(inst), "cfb", alg); if (err) goto err_drop_spawn; inst->alg.base.cra_priority = alg->cra_priority; /* we're a stream cipher independend of the crypto cra_blocksize */ inst->alg.base.cra_blocksize = 1; inst->alg.base.cra_alignmask = alg->cra_alignmask; inst->alg.ivsize = alg->cra_blocksize; inst->alg.min_keysize = alg->cra_cipher.cia_min_keysize; inst->alg.max_keysize = alg->cra_cipher.cia_max_keysize; inst->alg.base.cra_ctxsize = sizeof(struct crypto_cfb_ctx); inst->alg.init = crypto_cfb_init_tfm; inst->alg.exit = crypto_cfb_exit_tfm; inst->alg.setkey = crypto_cfb_setkey; inst->alg.encrypt = crypto_cfb_encrypt; inst->alg.decrypt = crypto_cfb_decrypt; inst->free = crypto_cfb_free; err = skcipher_register_instance(tmpl, inst); if (err) goto err_drop_spawn; out: return err; err_drop_spawn: crypto_drop_spawn(spawn); err_free_inst: kfree(inst); goto out; } static struct crypto_template crypto_cfb_tmpl = { .name = "cfb", .create = crypto_cfb_create, .module = THIS_MODULE, }; static int __init crypto_cfb_module_init(void) { return crypto_register_template(&crypto_cfb_tmpl); } static void __exit crypto_cfb_module_exit(void) { crypto_unregister_template(&crypto_cfb_tmpl); } module_init(crypto_cfb_module_init); module_exit(crypto_cfb_module_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("CFB block cipher algorithm"); MODULE_ALIAS_CRYPTO("cfb");


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