diff options
| -rw-r--r-- | crypto/Kconfig | 1 | ||||
| -rw-r--r-- | crypto/hmac.c | 241 |
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"); |