/* * Cryptographic API. * * HMAC: Keyed-Hashing for Message Authentication (RFC2104). * * Copyright (c) 2002 James Morris <jmorris@intercode.com.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)  * any later version. * */#include <linux/crypto.h>#include <linux/mm.h>#include <linux/highmem.h>#include <linux/slab.h>#include <linux/scatterlist.h>#include "internal.h" static void hash_key(struct crypto_tfm *tfm, u8 *key, unsigned int keylen){	struct scatterlist tmp;		sg_set_buf(&tmp, key, keylen);	crypto_digest_digest(tfm, &tmp, 1, key);} int crypto_alloc_hmac_block(struct crypto_tfm *tfm){	int ret = 0; 	BUG_ON(!crypto_tfm_alg_blocksize(tfm));		tfm->crt_digest.dit_hmac_block = kmalloc(crypto_tfm_alg_blocksize(tfm),	                                         GFP_KERNEL);	if (tfm->crt_digest.dit_hmac_block == NULL)		ret = -ENOMEM; 	return ret;		} void crypto_free_hmac_block(struct crypto_tfm *tfm){	kfree(tfm->crt_digest.dit_hmac_block);} void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen){	unsigned int i;	struct scatterlist tmp;	char *ipad = tfm->crt_digest.dit_hmac_block;		if (*keylen > crypto_tfm_alg_blocksize(tfm)) {		hash_key(tfm, key, *keylen);		*keylen = crypto_tfm_alg_digestsize(tfm);	} 	memset(ipad, 0, crypto_tfm_alg_blocksize(tfm));	memcpy(ipad, key, *keylen); 	for (i = 0; i < crypto_tfm_alg_blocksize(tfm); i++)		ipad[i] ^= 0x36; 	sg_set_buf(&tmp, ipad, crypto_tfm_alg_blocksize(tfm));		crypto_digest_init(tfm);	crypto_digest_update(tfm, &tmp, 1);} void crypto_hmac_update(struct crypto_tfm *tfm,                        struct scatterlist *sg, unsigned int nsg){	crypto_digest_update(tfm, sg, nsg);} void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key,                       unsigned int *keylen, u8 *out){	unsigned int i;	struct scatterlist tmp;	char *opad = tfm->crt_digest.dit_hmac_block;		if (*keylen > crypto_tfm_alg_blocksize(tfm)) {		hash_key(tfm, key, *keylen);		*keylen = crypto_tfm_alg_digestsize(tfm);	} 	crypto_digest_final(tfm, out); 	memset(opad, 0, crypto_tfm_alg_blocksize(tfm));	memcpy(opad, key, *keylen);			for (i = 0; i < crypto_tfm_alg_blocksize(tfm); i++)		opad[i] ^= 0x5c; 	sg_set_buf(&tmp, opad, crypto_tfm_alg_blocksize(tfm)); 	crypto_digest_init(tfm);	crypto_digest_update(tfm, &tmp, 1);		sg_set_buf(&tmp, out, crypto_tfm_alg_digestsize(tfm));		crypto_digest_update(tfm, &tmp, 1);	crypto_digest_final(tfm, out);} void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen,                 struct scatterlist *sg, unsigned int nsg, u8 *out){	crypto_hmac_init(tfm, key, keylen);	crypto_hmac_update(tfm, sg, nsg);	crypto_hmac_final(tfm, key, keylen, out);} EXPORT_SYMBOL_GPL(crypto_hmac_init);EXPORT_SYMBOL_GPL(crypto_hmac_update);EXPORT_SYMBOL_GPL(crypto_hmac_final);EXPORT_SYMBOL_GPL(crypto_hmac);