--- /dev/null
+/*
+ * 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/internal/hash.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
+ 0x02020202, 0x02020202, 0x02020202, 0x02020202,
+ 0x03030303, 0x03030303, 0x03030303, 0x03030303};
+
+/*
+ * +------------------------
+ * | <parent tfm>
+ * +------------------------
+ * | xcbc_tfm_ctx
+ * +------------------------
+ * | consts (block size * 2)
+ * +------------------------
+ */
+struct xcbc_tfm_ctx {
+ struct crypto_cipher *child;
+ u8 ctx[];
+};
+
+/*
+ * +------------------------
+ * | <shash desc>
+ * +------------------------
+ * | xcbc_desc_ctx
+ * +------------------------
+ * | odds (block size)
+ * +------------------------
+ * | prev (block size)
+ * +------------------------
+ */
+struct xcbc_desc_ctx {
+ unsigned int len;
+ u8 ctx[];
+};
+
+static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
+ const u8 *inkey, unsigned int keylen)
+{
+ unsigned long alignmask = crypto_shash_alignmask(parent);
+ struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent);
+ int bs = crypto_shash_blocksize(parent);
+ u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
+ int err = 0;
+ u8 key1[bs];
+
+ if ((err = crypto_cipher_setkey(ctx->child, inkey, keylen)))
+ return err;
+
+ crypto_cipher_encrypt_one(ctx->child, consts, (u8 *)ks + bs);
+ crypto_cipher_encrypt_one(ctx->child, consts + bs, (u8 *)ks + bs * 2);
+ crypto_cipher_encrypt_one(ctx->child, key1, (u8 *)ks);
+
+ return crypto_cipher_setkey(ctx->child, key1, bs);
+
+}
+
+static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
+{
+ unsigned long alignmask = crypto_shash_alignmask(pdesc->tfm);
+ struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
+ int bs = crypto_shash_blocksize(pdesc->tfm);
+ u8 *prev = PTR_ALIGN(&ctx->ctx[0], alignmask + 1) + bs;
+
+ ctx->len = 0;
+ memset(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;
+ unsigned long alignmask = crypto_shash_alignmask(parent);
+ struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);
+ struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
+ struct crypto_cipher *tfm = tctx->child;
+ int bs = crypto_shash_blocksize(parent);
+ u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
+ u8 *prev = odds + bs;
+
+ /* checking the data can fill the block */
+ if ((ctx->len + len) <= bs) {
+ memcpy(odds + ctx->len, p, len);
+ ctx->len += len;
+ return 0;
+ }
+
+ /* filling odds with new data and encrypting it */
+ memcpy(odds + ctx->len, p, bs - ctx->len);
+ len -= bs - ctx->len;
+ p += bs - ctx->len;
+
+ crypto_xor(prev, odds, bs);
+ crypto_cipher_encrypt_one(tfm, prev, prev);
+
+ /* clearing the length */
+ ctx->len = 0;
+
+ /* encrypting the rest of data */
+ while (len > bs) {
+ crypto_xor(prev, p, bs);
+ crypto_cipher_encrypt_one(tfm, prev, prev);
+ p += bs;
+ len -= bs;
+ }
+
+ /* keeping the surplus of blocksize */
+ if (len) {
+ memcpy(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;
+ unsigned long alignmask = crypto_shash_alignmask(parent);
+ struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);
+ struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);
+ struct crypto_cipher *tfm = tctx->child;
+ int bs = crypto_shash_blocksize(parent);
+ u8 *consts = PTR_ALIGN(&tctx->ctx[0], alignmask + 1);
+ u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);
+ u8 *prev = odds + bs;
+ unsigned int offset = 0;
+
+ if (ctx->len != bs) {
+ unsigned int rlen;
+ u8 *p = odds + ctx->len;
+
+ *p = 0x80;
+ p++;
+
+ rlen = bs - ctx->len -1;
+ if (rlen)
+ memset(p, 0, rlen);
+
+ offset += bs;
+ }
+
+ crypto_xor(prev, odds, bs);
+ crypto_xor(prev, consts + offset, bs);
+
+ crypto_cipher_encrypt_one(tfm, out, 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 xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ cipher = crypto_spawn_cipher(spawn);
+ if (IS_ERR(cipher))
+ return PTR_ERR(cipher);
+
+ ctx->child = cipher;
+
+ return 0;
+};
+
+static void xcbc_exit_tfm(struct crypto_tfm *tfm)
+{
+ struct xcbc_tfm_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;
+ unsigned long alignmask;
+ 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);
+ err = PTR_ERR(inst);
+ 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;
+
+ alignmask = alg->cra_alignmask | 3;
+ inst->alg.base.cra_alignmask = alignmask;
+ inst->alg.base.cra_priority = alg->cra_priority;
+ inst->alg.base.cra_blocksize = alg->cra_blocksize;
+
+ inst->alg.digestsize = alg->cra_blocksize;
+ inst->alg.descsize = ALIGN(sizeof(struct xcbc_desc_ctx),
+ crypto_tfm_ctx_alignment()) +
+ (alignmask &
+ ~(crypto_tfm_ctx_alignment() - 1)) +
+ alg->cra_blocksize * 2;
+
+ inst->alg.base.cra_ctxsize = ALIGN(sizeof(struct xcbc_tfm_ctx),
+ alignmask + 1) +
+ alg->cra_blocksize * 2;
+ 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");
+MODULE_ALIAS_CRYPTO("xcbc");
Code Review / kvmfornfv.git / blobdiff