|  | /* | 
|  | * Copyright (C)2006 USAGI/WIDE Project | 
|  | * | 
|  | * This program is free software; you can redistribute it and/or modify | 
|  | * it under the terms of the GNU General Public License as published by | 
|  | * the Free Software Foundation; either version 2 of the License, or | 
|  | * (at your option) any later version. | 
|  | * | 
|  | * This program is distributed in the hope that it will be useful, | 
|  | * but WITHOUT ANY WARRANTY; without even the implied warranty of | 
|  | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
|  | * GNU General Public License for more details. | 
|  | * | 
|  | * You should have received a copy of the GNU General Public License | 
|  | * along with this program; if not, write to the Free Software | 
|  | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA | 
|  | * | 
|  | * Author: | 
|  | * 	Kazunori Miyazawa <miyazawa@linux-ipv6.org> | 
|  | */ | 
|  |  | 
|  | #include <crypto/scatterwalk.h> | 
|  | #include <linux/crypto.h> | 
|  | #include <linux/err.h> | 
|  | #include <linux/hardirq.h> | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/mm.h> | 
|  | #include <linux/rtnetlink.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/scatterlist.h> | 
|  |  | 
|  | static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101, | 
|  | 0x02020202, 0x02020202, 0x02020202, 0x02020202, | 
|  | 0x03030303, 0x03030303, 0x03030303, 0x03030303}; | 
|  | /* | 
|  | * +------------------------ | 
|  | * | <parent tfm> | 
|  | * +------------------------ | 
|  | * | crypto_xcbc_ctx | 
|  | * +------------------------ | 
|  | * | odds (block size) | 
|  | * +------------------------ | 
|  | * | prev (block size) | 
|  | * +------------------------ | 
|  | * | key (block size) | 
|  | * +------------------------ | 
|  | * | consts (block size * 3) | 
|  | * +------------------------ | 
|  | */ | 
|  | struct crypto_xcbc_ctx { | 
|  | struct crypto_cipher *child; | 
|  | u8 *odds; | 
|  | u8 *prev; | 
|  | u8 *key; | 
|  | u8 *consts; | 
|  | void (*xor)(u8 *a, const u8 *b, unsigned int bs); | 
|  | unsigned int keylen; | 
|  | unsigned int len; | 
|  | }; | 
|  |  | 
|  | static void xor_128(u8 *a, const u8 *b, unsigned int bs) | 
|  | { | 
|  | ((u32 *)a)[0] ^= ((u32 *)b)[0]; | 
|  | ((u32 *)a)[1] ^= ((u32 *)b)[1]; | 
|  | ((u32 *)a)[2] ^= ((u32 *)b)[2]; | 
|  | ((u32 *)a)[3] ^= ((u32 *)b)[3]; | 
|  | } | 
|  |  | 
|  | static int _crypto_xcbc_digest_setkey(struct crypto_hash *parent, | 
|  | struct crypto_xcbc_ctx *ctx) | 
|  | { | 
|  | int bs = crypto_hash_blocksize(parent); | 
|  | int err = 0; | 
|  | u8 key1[bs]; | 
|  |  | 
|  | if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen))) | 
|  | return err; | 
|  |  | 
|  | crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts); | 
|  |  | 
|  | return crypto_cipher_setkey(ctx->child, key1, bs); | 
|  | } | 
|  |  | 
|  | static int crypto_xcbc_digest_setkey(struct crypto_hash *parent, | 
|  | const u8 *inkey, unsigned int keylen) | 
|  | { | 
|  | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent); | 
|  |  | 
|  | if (keylen != crypto_cipher_blocksize(ctx->child)) | 
|  | return -EINVAL; | 
|  |  | 
|  | ctx->keylen = keylen; | 
|  | memcpy(ctx->key, inkey, keylen); | 
|  | ctx->consts = (u8*)ks; | 
|  |  | 
|  | return _crypto_xcbc_digest_setkey(parent, ctx); | 
|  | } | 
|  |  | 
|  | static int crypto_xcbc_digest_init(struct hash_desc *pdesc) | 
|  | { | 
|  | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(pdesc->tfm); | 
|  | int bs = crypto_hash_blocksize(pdesc->tfm); | 
|  |  | 
|  | ctx->len = 0; | 
|  | memset(ctx->odds, 0, bs); | 
|  | memset(ctx->prev, 0, bs); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int crypto_xcbc_digest_update2(struct hash_desc *pdesc, | 
|  | struct scatterlist *sg, | 
|  | unsigned int nbytes) | 
|  | { | 
|  | struct crypto_hash *parent = pdesc->tfm; | 
|  | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent); | 
|  | struct crypto_cipher *tfm = ctx->child; | 
|  | int bs = crypto_hash_blocksize(parent); | 
|  |  | 
|  | for (;;) { | 
|  | struct page *pg = sg_page(sg); | 
|  | unsigned int offset = sg->offset; | 
|  | unsigned int slen = sg->length; | 
|  |  | 
|  | if (unlikely(slen > nbytes)) | 
|  | slen = nbytes; | 
|  |  | 
|  | nbytes -= slen; | 
|  |  | 
|  | while (slen > 0) { | 
|  | unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset); | 
|  | char *p = crypto_kmap(pg, 0) + offset; | 
|  |  | 
|  | /* checking the data can fill the block */ | 
|  | if ((ctx->len + len) <= bs) { | 
|  | memcpy(ctx->odds + ctx->len, p, len); | 
|  | ctx->len += len; | 
|  | slen -= len; | 
|  |  | 
|  | /* checking the rest of the page */ | 
|  | if (len + offset >= PAGE_SIZE) { | 
|  | offset = 0; | 
|  | pg++; | 
|  | } else | 
|  | offset += len; | 
|  |  | 
|  | crypto_kunmap(p, 0); | 
|  | crypto_yield(pdesc->flags); | 
|  | continue; | 
|  | } | 
|  |  | 
|  | /* filling odds with new data and encrypting it */ | 
|  | memcpy(ctx->odds + ctx->len, p, bs - ctx->len); | 
|  | len -= bs - ctx->len; | 
|  | p += bs - ctx->len; | 
|  |  | 
|  | ctx->xor(ctx->prev, ctx->odds, bs); | 
|  | crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev); | 
|  |  | 
|  | /* clearing the length */ | 
|  | ctx->len = 0; | 
|  |  | 
|  | /* encrypting the rest of data */ | 
|  | while (len > bs) { | 
|  | ctx->xor(ctx->prev, p, bs); | 
|  | crypto_cipher_encrypt_one(tfm, ctx->prev, | 
|  | ctx->prev); | 
|  | p += bs; | 
|  | len -= bs; | 
|  | } | 
|  |  | 
|  | /* keeping the surplus of blocksize */ | 
|  | if (len) { | 
|  | memcpy(ctx->odds, p, len); | 
|  | ctx->len = len; | 
|  | } | 
|  | crypto_kunmap(p, 0); | 
|  | crypto_yield(pdesc->flags); | 
|  | slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset); | 
|  | offset = 0; | 
|  | pg++; | 
|  | } | 
|  |  | 
|  | if (!nbytes) | 
|  | break; | 
|  | sg = scatterwalk_sg_next(sg); | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int crypto_xcbc_digest_update(struct hash_desc *pdesc, | 
|  | struct scatterlist *sg, | 
|  | unsigned int nbytes) | 
|  | { | 
|  | if (WARN_ON_ONCE(in_irq())) | 
|  | return -EDEADLK; | 
|  | return crypto_xcbc_digest_update2(pdesc, sg, nbytes); | 
|  | } | 
|  |  | 
|  | static int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out) | 
|  | { | 
|  | struct crypto_hash *parent = pdesc->tfm; | 
|  | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent); | 
|  | struct crypto_cipher *tfm = ctx->child; | 
|  | int bs = crypto_hash_blocksize(parent); | 
|  | int err = 0; | 
|  |  | 
|  | if (ctx->len == bs) { | 
|  | u8 key2[bs]; | 
|  |  | 
|  | if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0) | 
|  | return err; | 
|  |  | 
|  | crypto_cipher_encrypt_one(tfm, key2, | 
|  | (u8 *)(ctx->consts + bs)); | 
|  |  | 
|  | ctx->xor(ctx->prev, ctx->odds, bs); | 
|  | ctx->xor(ctx->prev, key2, bs); | 
|  | _crypto_xcbc_digest_setkey(parent, ctx); | 
|  |  | 
|  | crypto_cipher_encrypt_one(tfm, out, ctx->prev); | 
|  | } else { | 
|  | u8 key3[bs]; | 
|  | unsigned int rlen; | 
|  | u8 *p = ctx->odds + ctx->len; | 
|  | *p = 0x80; | 
|  | p++; | 
|  |  | 
|  | rlen = bs - ctx->len -1; | 
|  | if (rlen) | 
|  | memset(p, 0, rlen); | 
|  |  | 
|  | if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0) | 
|  | return err; | 
|  |  | 
|  | crypto_cipher_encrypt_one(tfm, key3, | 
|  | (u8 *)(ctx->consts + bs * 2)); | 
|  |  | 
|  | ctx->xor(ctx->prev, ctx->odds, bs); | 
|  | ctx->xor(ctx->prev, key3, bs); | 
|  |  | 
|  | _crypto_xcbc_digest_setkey(parent, ctx); | 
|  |  | 
|  | crypto_cipher_encrypt_one(tfm, out, ctx->prev); | 
|  | } | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int crypto_xcbc_digest(struct hash_desc *pdesc, | 
|  | struct scatterlist *sg, unsigned int nbytes, u8 *out) | 
|  | { | 
|  | if (WARN_ON_ONCE(in_irq())) | 
|  | return -EDEADLK; | 
|  |  | 
|  | crypto_xcbc_digest_init(pdesc); | 
|  | crypto_xcbc_digest_update2(pdesc, sg, nbytes); | 
|  | return crypto_xcbc_digest_final(pdesc, out); | 
|  | } | 
|  |  | 
|  | static int xcbc_init_tfm(struct crypto_tfm *tfm) | 
|  | { | 
|  | struct crypto_cipher *cipher; | 
|  | struct crypto_instance *inst = (void *)tfm->__crt_alg; | 
|  | struct crypto_spawn *spawn = crypto_instance_ctx(inst); | 
|  | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm)); | 
|  | int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm)); | 
|  |  | 
|  | cipher = crypto_spawn_cipher(spawn); | 
|  | if (IS_ERR(cipher)) | 
|  | return PTR_ERR(cipher); | 
|  |  | 
|  | switch(bs) { | 
|  | case 16: | 
|  | ctx->xor = xor_128; | 
|  | break; | 
|  | default: | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | ctx->child = cipher; | 
|  | ctx->odds = (u8*)(ctx+1); | 
|  | ctx->prev = ctx->odds + bs; | 
|  | ctx->key = ctx->prev + bs; | 
|  |  | 
|  | return 0; | 
|  | }; | 
|  |  | 
|  | static void xcbc_exit_tfm(struct crypto_tfm *tfm) | 
|  | { | 
|  | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm)); | 
|  | crypto_free_cipher(ctx->child); | 
|  | } | 
|  |  | 
|  | static struct crypto_instance *xcbc_alloc(struct rtattr **tb) | 
|  | { | 
|  | struct crypto_instance *inst; | 
|  | struct crypto_alg *alg; | 
|  | int err; | 
|  |  | 
|  | err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH); | 
|  | 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); | 
|  |  | 
|  | switch(alg->cra_blocksize) { | 
|  | case 16: | 
|  | break; | 
|  | default: | 
|  | inst = ERR_PTR(-EINVAL); | 
|  | goto out_put_alg; | 
|  | } | 
|  |  | 
|  | inst = crypto_alloc_instance("xcbc", alg); | 
|  | if (IS_ERR(inst)) | 
|  | goto out_put_alg; | 
|  |  | 
|  | inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH; | 
|  | inst->alg.cra_priority = alg->cra_priority; | 
|  | inst->alg.cra_blocksize = alg->cra_blocksize; | 
|  | inst->alg.cra_alignmask = alg->cra_alignmask; | 
|  | inst->alg.cra_type = &crypto_hash_type; | 
|  |  | 
|  | inst->alg.cra_hash.digestsize = alg->cra_blocksize; | 
|  | inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) + | 
|  | ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *)); | 
|  | inst->alg.cra_init = xcbc_init_tfm; | 
|  | inst->alg.cra_exit = xcbc_exit_tfm; | 
|  |  | 
|  | inst->alg.cra_hash.init = crypto_xcbc_digest_init; | 
|  | inst->alg.cra_hash.update = crypto_xcbc_digest_update; | 
|  | inst->alg.cra_hash.final = crypto_xcbc_digest_final; | 
|  | inst->alg.cra_hash.digest = crypto_xcbc_digest; | 
|  | inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey; | 
|  |  | 
|  | out_put_alg: | 
|  | crypto_mod_put(alg); | 
|  | return inst; | 
|  | } | 
|  |  | 
|  | static void xcbc_free(struct crypto_instance *inst) | 
|  | { | 
|  | crypto_drop_spawn(crypto_instance_ctx(inst)); | 
|  | kfree(inst); | 
|  | } | 
|  |  | 
|  | static struct crypto_template crypto_xcbc_tmpl = { | 
|  | .name = "xcbc", | 
|  | .alloc = xcbc_alloc, | 
|  | .free = xcbc_free, | 
|  | .module = THIS_MODULE, | 
|  | }; | 
|  |  | 
|  | static int __init crypto_xcbc_module_init(void) | 
|  | { | 
|  | return crypto_register_template(&crypto_xcbc_tmpl); | 
|  | } | 
|  |  | 
|  | static void __exit crypto_xcbc_module_exit(void) | 
|  | { | 
|  | crypto_unregister_template(&crypto_xcbc_tmpl); | 
|  | } | 
|  |  | 
|  | module_init(crypto_xcbc_module_init); | 
|  | module_exit(crypto_xcbc_module_exit); | 
|  |  | 
|  | MODULE_LICENSE("GPL"); | 
|  | MODULE_DESCRIPTION("XCBC keyed hash algorithm"); |