/* * Cryptographic API. * * 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) * any later version. * */ #include <crypto/internal/hash.h>#include <crypto/scatterwalk.h>#include <linux/err.h>#include <linux/init.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/scatterlist.h>#include <linux/string.h> struct hmac_ctx {	struct crypto_shash *hash;}; 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_shash *tfm){	return align_ptr(crypto_shash_ctx_aligned(tfm) +			 crypto_shash_statesize(tfm) * 2,			 crypto_tfm_ctx_alignment());} static int hmac_setkey(struct crypto_shash *parent,		       const u8 *inkey, unsigned int keylen){	int bs = crypto_shash_blocksize(parent);	int ds = crypto_shash_digestsize(parent);	int ss = crypto_shash_statesize(parent);	char *ipad = crypto_shash_ctx_aligned(parent);	char *opad = ipad + ss;	struct hmac_ctx *ctx = align_ptr(opad + ss,					 crypto_tfm_ctx_alignment());	struct crypto_shash *hash = ctx->hash;	struct {		struct shash_desc shash;		char ctx[crypto_shash_descsize(hash)];	} desc;	unsigned int i; 	desc.shash.tfm = hash;	desc.shash.flags = crypto_shash_get_flags(parent) &			    CRYPTO_TFM_REQ_MAY_SLEEP; 	if (keylen > bs) {		int err; 		err = crypto_shash_digest(&desc.shash, inkey, keylen, ipad);		if (err)			return err; 		keylen = ds;	} else		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 crypto_shash_init(&desc.shash) ?:	       crypto_shash_update(&desc.shash, ipad, bs) ?:	       crypto_shash_export(&desc.shash, ipad) ?:	       crypto_shash_init(&desc.shash) ?:	       crypto_shash_update(&desc.shash, opad, bs) ?:	       crypto_shash_export(&desc.shash, opad);} static int hmac_export(struct shash_desc *pdesc, void *out){	struct shash_desc *desc = shash_desc_ctx(pdesc); 	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; 	return crypto_shash_export(desc, out);} static int hmac_import(struct shash_desc *pdesc, const void *in){	struct shash_desc *desc = shash_desc_ctx(pdesc);	struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm); 	desc->tfm = ctx->hash;	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; 	return crypto_shash_import(desc, in);} static int hmac_init(struct shash_desc *pdesc){	return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));} static int hmac_update(struct shash_desc *pdesc,		       const u8 *data, unsigned int nbytes){	struct shash_desc *desc = shash_desc_ctx(pdesc); 	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; 	return crypto_shash_update(desc, data, nbytes);} static int hmac_final(struct shash_desc *pdesc, u8 *out){	struct crypto_shash *parent = pdesc->tfm;	int ds = crypto_shash_digestsize(parent);	int ss = crypto_shash_statesize(parent);	char *opad = crypto_shash_ctx_aligned(parent) + ss;	struct shash_desc *desc = shash_desc_ctx(pdesc); 	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; 	return crypto_shash_final(desc, out) ?:	       crypto_shash_import(desc, opad) ?:	       crypto_shash_finup(desc, out, ds, out);} static int hmac_finup(struct shash_desc *pdesc, const u8 *data,		      unsigned int nbytes, u8 *out){ 	struct crypto_shash *parent = pdesc->tfm;	int ds = crypto_shash_digestsize(parent);	int ss = crypto_shash_statesize(parent);	char *opad = crypto_shash_ctx_aligned(parent) + ss;	struct shash_desc *desc = shash_desc_ctx(pdesc); 	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; 	return crypto_shash_finup(desc, data, nbytes, out) ?:	       crypto_shash_import(desc, opad) ?:	       crypto_shash_finup(desc, out, ds, out);} static int hmac_init_tfm(struct crypto_tfm *tfm){	struct crypto_shash *parent = __crypto_shash_cast(tfm);	struct crypto_shash *hash;	struct crypto_instance *inst = (void *)tfm->__crt_alg;	struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst);	struct hmac_ctx *ctx = hmac_ctx(parent); 	hash = crypto_spawn_shash(spawn);	if (IS_ERR(hash))		return PTR_ERR(hash); 	parent->descsize = sizeof(struct shash_desc) +			   crypto_shash_descsize(hash); 	ctx->hash = hash;	return 0;} static void hmac_exit_tfm(struct crypto_tfm *tfm){	struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm));	crypto_free_shash(ctx->hash);} static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb){	struct shash_instance *inst;	struct crypto_alg *alg;	struct shash_alg *salg;	int err;	int ds;	int ss; 	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);	if (err)		return err; 	salg = shash_attr_alg(tb[1], 0, 0);	if (IS_ERR(salg))		return PTR_ERR(salg); 	err = -EINVAL;	ds = salg->digestsize;	ss = salg->statesize;	alg = &salg->base;	if (ds > alg->cra_blocksize ||	    ss < alg->cra_blocksize)		goto out_put_alg; 	inst = shash_alloc_instance("hmac", alg);	err = PTR_ERR(inst);	if (IS_ERR(inst))		goto out_put_alg; 	err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg,				      shash_crypto_instance(inst));	if (err)		goto out_free_inst; 	inst->alg.base.cra_priority = alg->cra_priority;	inst->alg.base.cra_blocksize = alg->cra_blocksize;	inst->alg.base.cra_alignmask = alg->cra_alignmask; 	ss = ALIGN(ss, alg->cra_alignmask + 1);	inst->alg.digestsize = ds;	inst->alg.statesize = ss; 	inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +				     ALIGN(ss * 2, crypto_tfm_ctx_alignment()); 	inst->alg.base.cra_init = hmac_init_tfm;	inst->alg.base.cra_exit = hmac_exit_tfm; 	inst->alg.init = hmac_init;	inst->alg.update = hmac_update;	inst->alg.final = hmac_final;	inst->alg.finup = hmac_finup;	inst->alg.export = hmac_export;	inst->alg.import = hmac_import;	inst->alg.setkey = hmac_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 hmac_tmpl = {	.name = "hmac",	.create = hmac_create,	.free = shash_free_instance,	.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");