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  • shash.c 17.54 KiB
    /*
     * Synchronous Cryptographic Hash operations.
     *
     * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
     *
     * 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/scatterwalk.h>
    #include <crypto/internal/hash.h>
    #include <linux/err.h>
    #include <linux/kernel.h>
    #include <linux/module.h>
    #include <linux/slab.h>
    #include <linux/seq_file.h>
    #include <linux/cryptouser.h>
    #include <net/netlink.h>
    
    #include "internal.h"
    
    static const struct crypto_type crypto_shash_type;
    
    static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
    			   unsigned int keylen)
    {
    	return -ENOSYS;
    }
    
    static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
    				  unsigned int keylen)
    {
    	struct shash_alg *shash = crypto_shash_alg(tfm);
    	unsigned long alignmask = crypto_shash_alignmask(tfm);
    	unsigned long absize;
    	u8 *buffer, *alignbuffer;
    	int err;
    
    	absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
    	buffer = kmalloc(absize, GFP_KERNEL);
    	if (!buffer)
    		return -ENOMEM;
    
    	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
    	memcpy(alignbuffer, key, keylen);
    	err = shash->setkey(tfm, alignbuffer, keylen);
    	kzfree(buffer);
    	return err;
    }
    
    int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
    			unsigned int keylen)
    {
    	struct shash_alg *shash = crypto_shash_alg(tfm);
    	unsigned long alignmask = crypto_shash_alignmask(tfm);
    
    	if ((unsigned long)key & alignmask)
    		return shash_setkey_unaligned(tfm, key, keylen);
    
    	return shash->setkey(tfm, key, keylen);
    }
    EXPORT_SYMBOL_GPL(crypto_shash_setkey);
    
    static inline unsigned int shash_align_buffer_size(unsigned len,
    						   unsigned long mask)
    {
    	return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
    }
    
    static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
    				  unsigned int len)
    {
    	struct crypto_shash *tfm = desc->tfm;
    	struct shash_alg *shash = crypto_shash_alg(tfm);
    	unsigned long alignmask = crypto_shash_alignmask(tfm);
    	unsigned int unaligned_len = alignmask + 1 -
    				     ((unsigned long)data & alignmask);
    	u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
    		__attribute__ ((aligned));
    	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
    	int err;
    
    	if (unaligned_len > len)
    		unaligned_len = len;
    
    	memcpy(buf, data, unaligned_len);
    	err = shash->update(desc, buf, unaligned_len);
    	memset(buf, 0, unaligned_len);
    
    	return err ?:
    	       shash->update(desc, data + unaligned_len, len - unaligned_len);
    }
    
    int crypto_shash_update(struct shash_desc *desc, const u8 *data,
    			unsigned int len)
    {
    	struct crypto_shash *tfm = desc->tfm;
    	struct shash_alg *shash = crypto_shash_alg(tfm);
    	unsigned long alignmask = crypto_shash_alignmask(tfm);
    
    	if ((unsigned long)data & alignmask)
    		return shash_update_unaligned(desc, data, len);
    
    	return shash->update(desc, data, len);
    }
    EXPORT_SYMBOL_GPL(crypto_shash_update);
    
    static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
    {
    	struct crypto_shash *tfm = desc->tfm;
    	unsigned long alignmask = crypto_shash_alignmask(tfm);
    	struct shash_alg *shash = crypto_shash_alg(tfm);
    	unsigned int ds = crypto_shash_digestsize(tfm);
    	u8 ubuf[shash_align_buffer_size(ds, alignmask)]
    		__attribute__ ((aligned));
    	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
    	int err;
    
    	err = shash->final(desc, buf);
    	if (err)
    		goto out;
    
    	memcpy(out, buf, ds);
    
    out:
    	memset(buf, 0, ds);
    	return err;
    }
    
    int crypto_shash_final(struct shash_desc *desc, u8 *out)
    {
    	struct crypto_shash *tfm = desc->tfm;
    	struct shash_alg *shash = crypto_shash_alg(tfm);
    	unsigned long alignmask = crypto_shash_alignmask(tfm);
    
    	if ((unsigned long)out & alignmask)
    		return shash_final_unaligned(desc, out);
    
    	return shash->final(desc, out);
    }
    EXPORT_SYMBOL_GPL(crypto_shash_final);
    
    static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
    				 unsigned int len, u8 *out)
    {
    	return crypto_shash_update(desc, data, len) ?:
    	       crypto_shash_final(desc, out);
    }
    
    int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
    		       unsigned int len, u8 *out)
    {
    	struct crypto_shash *tfm = desc->tfm;
    	struct shash_alg *shash = crypto_shash_alg(tfm);
    	unsigned long alignmask = crypto_shash_alignmask(tfm);
    
    	if (((unsigned long)data | (unsigned long)out) & alignmask)
    		return shash_finup_unaligned(desc, data, len, out);
    
    	return shash->finup(desc, data, len, out);
    }
    EXPORT_SYMBOL_GPL(crypto_shash_finup);
    
    static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
    				  unsigned int len, u8 *out)
    {
    	return crypto_shash_init(desc) ?:
    	       crypto_shash_finup(desc, data, len, out);
    }
    
    int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
    			unsigned int len, u8 *out)
    {
    	struct crypto_shash *tfm = desc->tfm;
    	struct shash_alg *shash = crypto_shash_alg(tfm);
    	unsigned long alignmask = crypto_shash_alignmask(tfm);
    
    	if (((unsigned long)data | (unsigned long)out) & alignmask)
    		return shash_digest_unaligned(desc, data, len, out);
    
    	return shash->digest(desc, data, len, out);
    }
    EXPORT_SYMBOL_GPL(crypto_shash_digest);
    
    static int shash_default_export(struct shash_desc *desc, void *out)
    {
    	memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
    	return 0;
    }
    
    static int shash_default_import(struct shash_desc *desc, const void *in)
    {
    	memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
    	return 0;
    }
    
    static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
    			      unsigned int keylen)
    {
    	struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
    
    	return crypto_shash_setkey(*ctx, key, keylen);
    }
    
    static int shash_async_init(struct ahash_request *req)
    {
    	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
    	struct shash_desc *desc = ahash_request_ctx(req);
    
    	desc->tfm = *ctx;
    	desc->flags = req->base.flags;
    
    	return crypto_shash_init(desc);
    }
    
    int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
    {
    	struct crypto_hash_walk walk;
    	int nbytes;
    
    	for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
    	     nbytes = crypto_hash_walk_done(&walk, nbytes))
    		nbytes = crypto_shash_update(desc, walk.data, nbytes);
    
    	return nbytes;
    }
    EXPORT_SYMBOL_GPL(shash_ahash_update);
    
    static int shash_async_update(struct ahash_request *req)
    {
    	return shash_ahash_update(req, ahash_request_ctx(req));
    }
    
    static int shash_async_final(struct ahash_request *req)
    {
    	return crypto_shash_final(ahash_request_ctx(req), req->result);
    }
    
    int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
    {
    	struct crypto_hash_walk walk;
    	int nbytes;
    
    	nbytes = crypto_hash_walk_first(req, &walk);
    	if (!nbytes)
    		return crypto_shash_final(desc, req->result);
    
    	do {
    		nbytes = crypto_hash_walk_last(&walk) ?
    			 crypto_shash_finup(desc, walk.data, nbytes,
    					    req->result) :
    			 crypto_shash_update(desc, walk.data, nbytes);
    		nbytes = crypto_hash_walk_done(&walk, nbytes);
    	} while (nbytes > 0);
    
    	return nbytes;
    }
    EXPORT_SYMBOL_GPL(shash_ahash_finup);
    
    static int shash_async_finup(struct ahash_request *req)
    {
    	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
    	struct shash_desc *desc = ahash_request_ctx(req);
    
    	desc->tfm = *ctx;
    	desc->flags = req->base.flags;
    
    	return shash_ahash_finup(req, desc);
    }
    
    int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
    {
    	struct scatterlist *sg = req->src;
    	unsigned int offset = sg->offset;
    	unsigned int nbytes = req->nbytes;
    	int err;
    
    	if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
    		void *data;
    
    		data = kmap_atomic(sg_page(sg));
    		err = crypto_shash_digest(desc, data + offset, nbytes,
    					  req->result);
    		kunmap_atomic(data);
    		crypto_yield(desc->flags);
    	} else
    		err = crypto_shash_init(desc) ?:
    		      shash_ahash_finup(req, desc);
    
    	return err;
    }
    EXPORT_SYMBOL_GPL(shash_ahash_digest);
    
    static int shash_async_digest(struct ahash_request *req)
    {
    	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
    	struct shash_desc *desc = ahash_request_ctx(req);
    
    	desc->tfm = *ctx;
    	desc->flags = req->base.flags;
    
    	return shash_ahash_digest(req, desc);
    }
    
    static int shash_async_export(struct ahash_request *req, void *out)
    {
    	return crypto_shash_export(ahash_request_ctx(req), out);
    }
    
    static int shash_async_import(struct ahash_request *req, const void *in)
    {
    	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
    	struct shash_desc *desc = ahash_request_ctx(req);
    
    	desc->tfm = *ctx;
    	desc->flags = req->base.flags;
    
    	return crypto_shash_import(desc, in);
    }
    
    static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
    {
    	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
    
    	crypto_free_shash(*ctx);
    }
    
    int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
    {
    	struct crypto_alg *calg = tfm->__crt_alg;
    	struct shash_alg *alg = __crypto_shash_alg(calg);
    	struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
    	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
    	struct crypto_shash *shash;
    
    	if (!crypto_mod_get(calg))
    		return -EAGAIN;
    
    	shash = crypto_create_tfm(calg, &crypto_shash_type);
    	if (IS_ERR(shash)) {
    		crypto_mod_put(calg);
    		return PTR_ERR(shash);
    	}
    
    	*ctx = shash;
    	tfm->exit = crypto_exit_shash_ops_async;
    
    	crt->init = shash_async_init;
    	crt->update = shash_async_update;
    	crt->final = shash_async_final;
    	crt->finup = shash_async_finup;
    	crt->digest = shash_async_digest;
    
    	if (alg->setkey)
    		crt->setkey = shash_async_setkey;
    	if (alg->export)
    		crt->export = shash_async_export;
    	if (alg->import)
    		crt->import = shash_async_import;
    
    	crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
    
    	return 0;
    }
    
    static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
    			       unsigned int keylen)
    {
    	struct shash_desc **descp = crypto_hash_ctx(tfm);
    	struct shash_desc *desc = *descp;
    
    	return crypto_shash_setkey(desc->tfm, key, keylen);
    }
    
    static int shash_compat_init(struct hash_desc *hdesc)
    {
    	struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
    	struct shash_desc *desc = *descp;
    
    	desc->flags = hdesc->flags;
    
    	return crypto_shash_init(desc);
    }
    
    static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
    			       unsigned int len)
    {
    	struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
    	struct shash_desc *desc = *descp;
    	struct crypto_hash_walk walk;
    	int nbytes;
    
    	for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
    	     nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
    		nbytes = crypto_shash_update(desc, walk.data, nbytes);
    
    	return nbytes;
    }
    
    static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
    {
    	struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
    
    	return crypto_shash_final(*descp, out);
    }
    
    static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
    			       unsigned int nbytes, u8 *out)
    {
    	unsigned int offset = sg->offset;
    	int err;
    
    	if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
    		struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
    		struct shash_desc *desc = *descp;
    		void *data;
    
    		desc->flags = hdesc->flags;
    
    		data = kmap_atomic(sg_page(sg));
    		err = crypto_shash_digest(desc, data + offset, nbytes, out);
    		kunmap_atomic(data);
    		crypto_yield(desc->flags);
    		goto out;
    	}
    
    	err = shash_compat_init(hdesc);
    	if (err)
    		goto out;
    
    	err = shash_compat_update(hdesc, sg, nbytes);
    	if (err)
    		goto out;
    
    	err = shash_compat_final(hdesc, out);
    
    out:
    	return err;
    }
    
    static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
    {
    	struct shash_desc **descp = crypto_tfm_ctx(tfm);
    	struct shash_desc *desc = *descp;
    
    	crypto_free_shash(desc->tfm);
    	kzfree(desc);
    }
    
    static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
    {
    	struct hash_tfm *crt = &tfm->crt_hash;
    	struct crypto_alg *calg = tfm->__crt_alg;
    	struct shash_alg *alg = __crypto_shash_alg(calg);
    	struct shash_desc **descp = crypto_tfm_ctx(tfm);
    	struct crypto_shash *shash;
    	struct shash_desc *desc;
    
    	if (!crypto_mod_get(calg))
    		return -EAGAIN;
    
    	shash = crypto_create_tfm(calg, &crypto_shash_type);
    	if (IS_ERR(shash)) {
    		crypto_mod_put(calg);
    		return PTR_ERR(shash);
    	}
    
    	desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
    		       GFP_KERNEL);
    	if (!desc) {
    		crypto_free_shash(shash);
    		return -ENOMEM;
    	}
    
    	*descp = desc;
    	desc->tfm = shash;
    	tfm->exit = crypto_exit_shash_ops_compat;
    
    	crt->init = shash_compat_init;
    	crt->update = shash_compat_update;
    	crt->final  = shash_compat_final;
    	crt->digest = shash_compat_digest;
    	crt->setkey = shash_compat_setkey;
    
    	crt->digestsize = alg->digestsize;
    
    	return 0;
    }
    
    static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
    {
    	switch (mask & CRYPTO_ALG_TYPE_MASK) {
    	case CRYPTO_ALG_TYPE_HASH_MASK:
    		return crypto_init_shash_ops_compat(tfm);
    	}
    
    	return -EINVAL;
    }
    
    static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
    					 u32 mask)
    {
    	switch (mask & CRYPTO_ALG_TYPE_MASK) {
    	case CRYPTO_ALG_TYPE_HASH_MASK:
    		return sizeof(struct shash_desc *);
    	}
    
    	return 0;
    }
    
    static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
    {
    	struct crypto_shash *hash = __crypto_shash_cast(tfm);
    
    	hash->descsize = crypto_shash_alg(hash)->descsize;
    	return 0;
    }
    
    static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
    {
    	return alg->cra_ctxsize;
    }
    
    #ifdef CONFIG_NET
    static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
    {
    	struct crypto_report_hash rhash;
    	struct shash_alg *salg = __crypto_shash_alg(alg);
    
    	strncpy(rhash.type, "shash", sizeof(rhash.type));
    
    	rhash.blocksize = alg->cra_blocksize;
    	rhash.digestsize = salg->digestsize;
    
    	if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
    		    sizeof(struct crypto_report_hash), &rhash))
    		goto nla_put_failure;
    	return 0;
    
    nla_put_failure:
    	return -EMSGSIZE;
    }
    #else
    static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
    {
    	return -ENOSYS;
    }
    #endif
    
    static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
    	__attribute__ ((unused));
    static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
    {
    	struct shash_alg *salg = __crypto_shash_alg(alg);
    
    	seq_printf(m, "type         : shash\n");
    	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
    	seq_printf(m, "digestsize   : %u\n", salg->digestsize);
    }
    
    static const struct crypto_type crypto_shash_type = {
    	.ctxsize = crypto_shash_ctxsize,
    	.extsize = crypto_shash_extsize,
    	.init = crypto_init_shash_ops,
    	.init_tfm = crypto_shash_init_tfm,
    #ifdef CONFIG_PROC_FS
    	.show = crypto_shash_show,
    #endif
    	.report = crypto_shash_report,
    	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
    	.maskset = CRYPTO_ALG_TYPE_MASK,
    	.type = CRYPTO_ALG_TYPE_SHASH,
    	.tfmsize = offsetof(struct crypto_shash, base),
    };
    
    struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
    					u32 mask)
    {
    	return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
    }
    EXPORT_SYMBOL_GPL(crypto_alloc_shash);
    
    static int shash_prepare_alg(struct shash_alg *alg)
    {
    	struct crypto_alg *base = &alg->base;
    
    	if (alg->digestsize > PAGE_SIZE / 8 ||
    	    alg->descsize > PAGE_SIZE / 8 ||
    	    alg->statesize > PAGE_SIZE / 8)
    		return -EINVAL;
    
    	base->cra_type = &crypto_shash_type;
    	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
    	base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
    
    	if (!alg->finup)
    		alg->finup = shash_finup_unaligned;
    	if (!alg->digest)
    		alg->digest = shash_digest_unaligned;
    	if (!alg->export) {
    		alg->export = shash_default_export;
    		alg->import = shash_default_import;
    		alg->statesize = alg->descsize;
    	}
    	if (!alg->setkey)
    		alg->setkey = shash_no_setkey;
    
    	return 0;
    }
    
    int crypto_register_shash(struct shash_alg *alg)
    {
    	struct crypto_alg *base = &alg->base;
    	int err;
    
    	err = shash_prepare_alg(alg);
    	if (err)
    		return err;
    
    	return crypto_register_alg(base);
    }
    EXPORT_SYMBOL_GPL(crypto_register_shash);
    
    int crypto_unregister_shash(struct shash_alg *alg)
    {
    	return crypto_unregister_alg(&alg->base);
    }
    EXPORT_SYMBOL_GPL(crypto_unregister_shash);
    
    int crypto_register_shashes(struct shash_alg *algs, int count)
    {
    	int i, ret;
    
    	for (i = 0; i < count; i++) {
    		ret = crypto_register_shash(&algs[i]);
    		if (ret)
    			goto err;
    	}
    
    	return 0;
    
    err:
    	for (--i; i >= 0; --i)
    		crypto_unregister_shash(&algs[i]);
    
    	return ret;
    }
    EXPORT_SYMBOL_GPL(crypto_register_shashes);
    
    int crypto_unregister_shashes(struct shash_alg *algs, int count)
    {
    	int i, ret;
    
    	for (i = count - 1; i >= 0; --i) {
    		ret = crypto_unregister_shash(&algs[i]);
    		if (ret)
    			pr_err("Failed to unregister %s %s: %d\n",
    			       algs[i].base.cra_driver_name,
    			       algs[i].base.cra_name, ret);
    	}
    
    	return 0;
    }
    EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
    
    int shash_register_instance(struct crypto_template *tmpl,
    			    struct shash_instance *inst)
    {
    	int err;
    
    	err = shash_prepare_alg(&inst->alg);
    	if (err)
    		return err;
    
    	return crypto_register_instance(tmpl, shash_crypto_instance(inst));
    }
    EXPORT_SYMBOL_GPL(shash_register_instance);
    
    void shash_free_instance(struct crypto_instance *inst)
    {
    	crypto_drop_spawn(crypto_instance_ctx(inst));
    	kfree(shash_instance(inst));
    }
    EXPORT_SYMBOL_GPL(shash_free_instance);
    
    int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
    			    struct shash_alg *alg,
    			    struct crypto_instance *inst)
    {
    	return crypto_init_spawn2(&spawn->base, &alg->base, inst,
    				  &crypto_shash_type);
    }
    EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
    
    struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
    {
    	struct crypto_alg *alg;
    
    	alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
    	return IS_ERR(alg) ? ERR_CAST(alg) :
    	       container_of(alg, struct shash_alg, base);
    }
    EXPORT_SYMBOL_GPL(shash_attr_alg);
    
    MODULE_LICENSE("GPL");
    MODULE_DESCRIPTION("Synchronous cryptographic hash type");