2 files changed, 236 insertions, 6 deletions

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 69c5f992bcd4..f07d9237950f 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -34,6 +34,7 @@ config CRYPTO_MANAGER
 
 config CRYPTO_HMAC
         bool "HMAC support"
+        select CRYPTO_HASH
         help
           HMAC: Keyed-Hashing for Message Authentication (RFC2104).
           This is required for IPSec.
diff --git a/crypto/hmac.c b/crypto/hmac.c
index ecf7b0a95b56..eac77e294740 100644
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -4,22 +4,30 @@
  * HMAC: Keyed-Hashing for Message Authentication (RFC2104).
  *
  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
  *
  * The HMAC implementation is derived from USAGI.
  * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
  *
  * 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) 
+ * Software Foundation; either version 2 of the License, or (at your option)
  * any later version.
  *
  */
-#include <linux/crypto.h>
-#include <linux/mm.h>
-#include <linux/highmem.h>
-#include <linux/slab.h>
+
+#include <crypto/algapi.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/scatterlist.h>
-#include "internal.h"
+#include <linux/slab.h>
+#include <linux/string.h>
+
+struct hmac_ctx {
+        struct crypto_hash *child;
+};
 
 static void hash_key(struct crypto_tfm *tfm, u8 *key, unsigned int keylen)
 {
@@ -122,3 +130,224 @@ EXPORT_SYMBOL_GPL(crypto_hmac_update);
 EXPORT_SYMBOL_GPL(crypto_hmac_final);
 EXPORT_SYMBOL_GPL(crypto_hmac);
 
+static inline void *align_ptr(void *p, unsigned int align)
+{
+        return (void *)ALIGN((unsigned long)p, align);
+}
+
+static inline struct hmac_ctx *hmac_ctx(struct crypto_hash *tfm)
+{
+        return align_ptr(crypto_hash_ctx_aligned(tfm) +
+                         crypto_hash_blocksize(tfm) * 2 +
+                         crypto_hash_digestsize(tfm), sizeof(void *));
+}
+
+static int hmac_setkey(struct crypto_hash *parent,
+                       const u8 *inkey, unsigned int keylen)
+{
+        int bs = crypto_hash_blocksize(parent);
+        int ds = crypto_hash_digestsize(parent);
+        char *ipad = crypto_hash_ctx_aligned(parent);
+        char *opad = ipad + bs;
+        char *digest = opad + bs;
+        struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));
+        struct crypto_hash *tfm = ctx->child;
+        unsigned int i;
+
+        if (keylen > bs) {
+                struct hash_desc desc;
+                struct scatterlist tmp;
+                int err;
+
+                desc.tfm = tfm;
+                desc.flags = crypto_hash_get_flags(parent);
+                desc.flags &= CRYPTO_TFM_REQ_MAY_SLEEP;
+                sg_set_buf(&tmp, inkey, keylen);
+
+                err = crypto_hash_digest(&desc, &tmp, keylen, digest);
+                if (err)
+                        return err;
+
+                inkey = digest;
+                keylen = ds;
+        }
+
+        memcpy(ipad, inkey, keylen);
+        memset(ipad + keylen, 0, bs - keylen);
+        memcpy(opad, ipad, bs);
+
+        for (i = 0; i < bs; i++) {
+                ipad[i] ^= 0x36;
+                opad[i] ^= 0x5c;
+        }
+
+        return 0;
+}
+
+static int hmac_init(struct hash_desc *pdesc)
+{
+        struct crypto_hash *parent = pdesc->tfm;
+        int bs = crypto_hash_blocksize(parent);
+        int ds = crypto_hash_digestsize(parent);
+        char *ipad = crypto_hash_ctx_aligned(parent);
+        struct hmac_ctx *ctx = align_ptr(ipad + bs * 2 + ds, sizeof(void *));
+        struct hash_desc desc;
+        struct scatterlist tmp;
+
+        desc.tfm = ctx->child;
+        desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+        sg_set_buf(&tmp, ipad, bs);
+
+        return unlikely(crypto_hash_init(&desc)) ?:
+               crypto_hash_update(&desc, &tmp, 1);
+}
+
+static int hmac_update(struct hash_desc *pdesc,
+                       struct scatterlist *sg, unsigned int nbytes)
+{
+        struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
+        struct hash_desc desc;
+
+        desc.tfm = ctx->child;
+        desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+
+        return crypto_hash_update(&desc, sg, nbytes);
+}
+
+static int hmac_final(struct hash_desc *pdesc, u8 *out)
+{
+        struct crypto_hash *parent = pdesc->tfm;
+        int bs = crypto_hash_blocksize(parent);
+        int ds = crypto_hash_digestsize(parent);
+        char *opad = crypto_hash_ctx_aligned(parent) + bs;
+        char *digest = opad + bs;
+        struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));
+        struct hash_desc desc;
+        struct scatterlist tmp;
+
+        desc.tfm = ctx->child;
+        desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+        sg_set_buf(&tmp, opad, bs + ds);
+
+        return unlikely(crypto_hash_final(&desc, digest)) ?:
+               crypto_hash_digest(&desc, &tmp, bs + ds, out);
+}
+
+static int hmac_digest(struct hash_desc *pdesc, struct scatterlist *sg,
+                       unsigned int nbytes, u8 *out)
+{
+        struct crypto_hash *parent = pdesc->tfm;
+        int bs = crypto_hash_blocksize(parent);
+        int ds = crypto_hash_digestsize(parent);
+        char *ipad = crypto_hash_ctx_aligned(parent);
+        char *opad = ipad + bs;
+        char *digest = opad + bs;
+        struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));
+        struct hash_desc desc;
+        struct scatterlist sg1[2];
+        struct scatterlist sg2[1];
+
+        desc.tfm = ctx->child;
+        desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+
+        sg_set_buf(sg1, ipad, bs);
+        sg1[1].page = (void *)sg;
+        sg1[1].length = 0;
+        sg_set_buf(sg2, opad, bs + ds);
+
+        return unlikely(crypto_hash_digest(&desc, sg1, nbytes + bs, digest)) ?:
+               crypto_hash_digest(&desc, sg2, bs + ds, out);
+}
+
+static int hmac_init_tfm(struct crypto_tfm *tfm)
+{
+        struct crypto_instance *inst = (void *)tfm->__crt_alg;
+        struct crypto_spawn *spawn = crypto_instance_ctx(inst);
+        struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));
+
+        tfm = crypto_spawn_tfm(spawn);
+        if (IS_ERR(tfm))
+                return PTR_ERR(tfm);
+
+        ctx->child = crypto_hash_cast(tfm);
+        return 0;
+}
+
+static void hmac_exit_tfm(struct crypto_tfm *tfm)
+{
+        struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));
+        crypto_free_hash(ctx->child);
+}
+
+static void hmac_free(struct crypto_instance *inst)
+{
+        crypto_drop_spawn(crypto_instance_ctx(inst));
+        kfree(inst);
+}
+
+static struct crypto_instance *hmac_alloc(void *param, unsigned int len)
+{
+        struct crypto_instance *inst;
+        struct crypto_alg *alg;
+
+        alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_HASH,
+                                  CRYPTO_ALG_TYPE_HASH_MASK | CRYPTO_ALG_ASYNC);
+        if (IS_ERR(alg))
+                return ERR_PTR(PTR_ERR(alg));
+
+        inst = crypto_alloc_instance("hmac", 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_digest.dia_digestsize;
+
+        inst->alg.cra_ctxsize = sizeof(struct hmac_ctx) +
+                                ALIGN(inst->alg.cra_blocksize * 2 +
+                                      inst->alg.cra_hash.digestsize,
+                                      sizeof(void *));
+
+        inst->alg.cra_init = hmac_init_tfm;
+        inst->alg.cra_exit = hmac_exit_tfm;
+
+        inst->alg.cra_hash.init = hmac_init;
+        inst->alg.cra_hash.update = hmac_update;
+        inst->alg.cra_hash.final = hmac_final;
+        inst->alg.cra_hash.digest = hmac_digest;
+        inst->alg.cra_hash.setkey = hmac_setkey;
+
+out_put_alg:
+        crypto_mod_put(alg);
+        return inst;
+}
+
+static struct crypto_template hmac_tmpl = {
+        .name = "hmac",
+        .alloc = hmac_alloc,
+        .free = hmac_free,
+        .module = THIS_MODULE,
+};
+
+static int __init hmac_module_init(void)
+{
+        return crypto_register_template(&hmac_tmpl);
+}
+
+static void __exit hmac_module_exit(void)
+{
+        crypto_unregister_template(&hmac_tmpl);
+}
+
+module_init(hmac_module_init);
+module_exit(hmac_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("HMAC hash algorithm");