155 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			155 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/*
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 * Cryptographic API.
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 *
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 * s390 implementation of the GHASH algorithm for GCM (Galois/Counter Mode).
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 *
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 * Copyright IBM Corp. 2011
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 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
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 */
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#include <crypto/internal/hash.h>
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#include <linux/module.h>
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#include <linux/cpufeature.h>
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#include <asm/cpacf.h>
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#define GHASH_BLOCK_SIZE	16
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#define GHASH_DIGEST_SIZE	16
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struct ghash_ctx {
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	u8 key[GHASH_BLOCK_SIZE];
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};
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struct ghash_desc_ctx {
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	u8 icv[GHASH_BLOCK_SIZE];
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	u8 key[GHASH_BLOCK_SIZE];
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	u8 buffer[GHASH_BLOCK_SIZE];
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	u32 bytes;
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};
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static int ghash_init(struct shash_desc *desc)
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{
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	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
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	struct ghash_ctx *ctx = crypto_shash_ctx(desc->tfm);
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	memset(dctx, 0, sizeof(*dctx));
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	memcpy(dctx->key, ctx->key, GHASH_BLOCK_SIZE);
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	return 0;
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}
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static int ghash_setkey(struct crypto_shash *tfm,
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			const u8 *key, unsigned int keylen)
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{
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	struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
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	if (keylen != GHASH_BLOCK_SIZE)
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		return -EINVAL;
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	memcpy(ctx->key, key, GHASH_BLOCK_SIZE);
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	return 0;
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}
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static int ghash_update(struct shash_desc *desc,
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			 const u8 *src, unsigned int srclen)
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{
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	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
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	unsigned int n;
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	u8 *buf = dctx->buffer;
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	if (dctx->bytes) {
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		u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
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		n = min(srclen, dctx->bytes);
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		dctx->bytes -= n;
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		srclen -= n;
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		memcpy(pos, src, n);
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		src += n;
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		if (!dctx->bytes) {
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			cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf,
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				   GHASH_BLOCK_SIZE);
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		}
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	}
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	n = srclen & ~(GHASH_BLOCK_SIZE - 1);
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	if (n) {
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		cpacf_kimd(CPACF_KIMD_GHASH, dctx, src, n);
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		src += n;
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		srclen -= n;
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	}
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	if (srclen) {
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		dctx->bytes = GHASH_BLOCK_SIZE - srclen;
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		memcpy(buf, src, srclen);
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	}
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	return 0;
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}
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static int ghash_flush(struct ghash_desc_ctx *dctx)
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{
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	u8 *buf = dctx->buffer;
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	if (dctx->bytes) {
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		u8 *pos = buf + (GHASH_BLOCK_SIZE - dctx->bytes);
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		memset(pos, 0, dctx->bytes);
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		cpacf_kimd(CPACF_KIMD_GHASH, dctx, buf, GHASH_BLOCK_SIZE);
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		dctx->bytes = 0;
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	}
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	return 0;
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}
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static int ghash_final(struct shash_desc *desc, u8 *dst)
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{
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	struct ghash_desc_ctx *dctx = shash_desc_ctx(desc);
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	int ret;
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	ret = ghash_flush(dctx);
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	if (!ret)
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		memcpy(dst, dctx->icv, GHASH_BLOCK_SIZE);
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	return ret;
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}
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static struct shash_alg ghash_alg = {
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	.digestsize	= GHASH_DIGEST_SIZE,
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	.init		= ghash_init,
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	.update		= ghash_update,
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	.final		= ghash_final,
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	.setkey		= ghash_setkey,
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	.descsize	= sizeof(struct ghash_desc_ctx),
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	.base		= {
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		.cra_name		= "ghash",
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		.cra_driver_name	= "ghash-s390",
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		.cra_priority		= 300,
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		.cra_blocksize		= GHASH_BLOCK_SIZE,
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		.cra_ctxsize		= sizeof(struct ghash_ctx),
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		.cra_module		= THIS_MODULE,
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	},
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};
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static int __init ghash_mod_init(void)
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{
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	if (!cpacf_query_func(CPACF_KIMD, CPACF_KIMD_GHASH))
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		return -ENODEV;
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	return crypto_register_shash(&ghash_alg);
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}
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static void __exit ghash_mod_exit(void)
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{
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	crypto_unregister_shash(&ghash_alg);
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}
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module_cpu_feature_match(S390_CPU_FEATURE_MSA, ghash_mod_init);
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module_exit(ghash_mod_exit);
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MODULE_ALIAS_CRYPTO("ghash");
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("GHASH hash function, s390 implementation");
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