diff options
Diffstat (limited to 'crypto/xcbc.c')
| -rw-r--r-- | crypto/xcbc.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/crypto/xcbc.c b/crypto/xcbc.c new file mode 100644 index 00000000000..9347eb6bcf6 --- /dev/null +++ b/crypto/xcbc.c @@ -0,0 +1,348 @@ +/* + * 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" + +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_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); +} + +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_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; +} + +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_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"); |