/* * 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 */ #include #include #include static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101, 0x02020202, 0x02020202, 0x02020202, 0x02020202, 0x03030303, 0x03030303, 0x03030303, 0x03030303}; /* * +------------------------ * | * +------------------------ * | 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_shash *parent, struct crypto_xcbc_ctx *ctx) { int bs = crypto_shash_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_shash *parent, const u8 *inkey, unsigned int keylen) { struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(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 shash_desc *pdesc) { struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(pdesc->tfm); int bs = crypto_shash_blocksize(pdesc->tfm); ctx->len = 0; memset(ctx->odds, 0, bs); memset(ctx->prev, 0, bs); return 0; } static int crypto_xcbc_digest_update(struct shash_desc *pdesc, const u8 *p, unsigned int len) { struct crypto_shash *parent = pdesc->tfm; struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent); struct crypto_cipher *tfm = ctx->child; int bs = crypto_shash_blocksize(parent); /* checking the data can fill the block */ if ((ctx->len + len) <= bs) { memcpy(ctx->odds + ctx->len, p, len); ctx->len += len; return 0; } /* 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; } return 0; } static int crypto_xcbc_digest_final(struct shash_desc *pdesc, u8 *out) { struct crypto_shash *parent = pdesc->tfm; struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent); struct crypto_cipher *tfm = ctx->child; int bs = crypto_shash_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 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_tfm_ctx(tfm); int bs = crypto_tfm_alg_blocksize(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_tfm_ctx(tfm); crypto_free_cipher(ctx->child); } static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb) { struct shash_instance *inst; struct crypto_alg *alg; int err; err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH); if (err) return err; alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, CRYPTO_ALG_TYPE_MASK); if (IS_ERR(alg)) return PTR_ERR(alg); switch(alg->cra_blocksize) { case 16: break; default: goto out_put_alg; } inst = shash_alloc_instance("xcbc", alg); if (IS_ERR(inst)) goto out_put_alg; err = crypto_init_spawn(shash_instance_ctx(inst), alg, shash_crypto_instance(inst), CRYPTO_ALG_TYPE_MASK); if (err) goto out_free_inst; inst->alg.base.cra_priority = alg->cra_priority; inst->alg.base.cra_blocksize = alg->cra_blocksize; inst->alg.base.cra_alignmask = alg->cra_alignmask; inst->alg.digestsize = alg->cra_blocksize; inst->alg.base.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) + ALIGN(alg->cra_blocksize * 3, sizeof(void *)); inst->alg.base.cra_init = xcbc_init_tfm; inst->alg.base.cra_exit = xcbc_exit_tfm; inst->alg.init = crypto_xcbc_digest_init; inst->alg.update = crypto_xcbc_digest_update; inst->alg.final = crypto_xcbc_digest_final; inst->alg.setkey = crypto_xcbc_digest_setkey; err = shash_register_instance(tmpl, inst); if (err) { out_free_inst: shash_free_instance(shash_crypto_instance(inst)); } out_put_alg: crypto_mod_put(alg); return err; } static struct crypto_template crypto_xcbc_tmpl = { .name = "xcbc", .create = xcbc_create, .free = shash_free_instance, .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");