| /* |
| * 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 <linux/crypto.h> |
| #include <linux/err.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/slab.h> |
| #include <linux/scatterlist.h> |
| #include "internal.h" |
| |
| 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_tfm *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; |
| |
| ctx->child->__crt_alg->cra_cipher.cia_encrypt(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_tfm_alg_blocksize(ctx->child)) |
| return -EINVAL; |
| |
| ctx->keylen = keylen; |
| memcpy(ctx->key, inkey, keylen); |
| ctx->consts = (u8*)ks; |
| |
| return _crypto_xcbc_digest_setkey(parent, ctx); |
| } |
| |
| 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; |
| } |
| |
| int crypto_xcbc_digest_update(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_tfm *tfm = ctx->child; |
| int bs = crypto_hash_blocksize(parent); |
| unsigned int i = 0; |
| |
| do { |
| |
| struct page *pg = sg[i].page; |
| unsigned int offset = sg[i].offset; |
| unsigned int slen = sg[i].length; |
| |
| 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(tfm->crt_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); |
| tfm->__crt_alg->cra_cipher.cia_encrypt(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); |
| tfm->__crt_alg->cra_cipher.cia_encrypt(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(tfm->crt_flags); |
| slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset); |
| offset = 0; |
| pg++; |
| } |
| nbytes-=sg[i].length; |
| i++; |
| } while (nbytes>0); |
| |
| return 0; |
| } |
| |
| 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_tfm *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; |
| |
| tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key2, (const u8*)(ctx->consts+bs)); |
| |
| ctx->xor(ctx->prev, ctx->odds, bs); |
| ctx->xor(ctx->prev, key2, bs); |
| _crypto_xcbc_digest_setkey(parent, ctx); |
| |
| tfm->__crt_alg->cra_cipher.cia_encrypt(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; |
| |
| tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key3, (const u8*)(ctx->consts+bs*2)); |
| |
| ctx->xor(ctx->prev, ctx->odds, bs); |
| ctx->xor(ctx->prev, key3, bs); |
| |
| _crypto_xcbc_digest_setkey(parent, ctx); |
| |
| tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev); |
| } |
| |
| return 0; |
| } |
| |
| static int crypto_xcbc_digest(struct hash_desc *pdesc, |
| struct scatterlist *sg, unsigned int nbytes, u8 *out) |
| { |
| crypto_xcbc_digest_init(pdesc); |
| crypto_xcbc_digest_update(pdesc, sg, nbytes); |
| return crypto_xcbc_digest_final(pdesc, out); |
| } |
| |
| static int xcbc_init_tfm(struct crypto_tfm *tfm) |
| { |
| 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)); |
| |
| tfm = crypto_spawn_tfm(spawn); |
| if (IS_ERR(tfm)) |
| return PTR_ERR(tfm); |
| |
| switch(bs) { |
| case 16: |
| ctx->xor = xor_128; |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| ctx->child = crypto_cipher_cast(tfm); |
| 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(void *param, unsigned int len) |
| { |
| struct crypto_instance *inst; |
| struct crypto_alg *alg; |
| alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER, |
| CRYPTO_ALG_TYPE_HASH_MASK | CRYPTO_ALG_ASYNC); |
| if (IS_ERR(alg)) |
| return ERR_PTR(PTR_ERR(alg)); |
| |
| switch(alg->cra_blocksize) { |
| case 16: |
| break; |
| default: |
| return ERR_PTR(PTR_ERR(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_flags & CRYPTO_ALG_TYPE_MASK) == |
| CRYPTO_ALG_TYPE_HASH ? 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"); |