[deliverable/linux.git] / arch / s390 / crypto / sha_common.c

/*
 * Cryptographic API.
 *
 * s390 generic implementation of the SHA Secure Hash Algorithms.
 *
 * Copyright IBM Corp. 2007
 * Author(s): Jan Glauber (jang@de.ibm.com)
 *
 * 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 <linux/module.h>
#include <asm/cpacf.h>
#include "sha.h"

int s390_sha_update(struct shash_desc *desc, const u8 *data, unsigned int len)
{
	struct s390_sha_ctx *ctx = shash_desc_ctx(desc);
	unsigned int bsize = crypto_shash_blocksize(desc->tfm);
	unsigned int index, n;

	/* how much is already in the buffer? */
	index = ctx->count & (bsize - 1);
	ctx->count += len;

	if ((index + len) < bsize)
		goto store;

	/* process one stored block */
	if (index) {
		memcpy(ctx->buf + index, data, bsize - index);
		cpacf_kimd(ctx->func, ctx->state, ctx->buf, bsize);
		data += bsize - index;
		len -= bsize - index;
		index = 0;
	}

	/* process as many blocks as possible */
	if (len >= bsize) {
		n = len & ~(bsize - 1);
		cpacf_kimd(ctx->func, ctx->state, data, n);
		data += n;
		len -= n;
	}
store:
	if (len)
		memcpy(ctx->buf + index , data, len);

	return 0;
}
EXPORT_SYMBOL_GPL(s390_sha_update);

int s390_sha_final(struct shash_desc *desc, u8 *out)
{
	struct s390_sha_ctx *ctx = shash_desc_ctx(desc);
	unsigned int bsize = crypto_shash_blocksize(desc->tfm);
	u64 bits;
	unsigned int index, end, plen;

	/* SHA-512 uses 128 bit padding length */
	plen = (bsize > SHA256_BLOCK_SIZE) ? 16 : 8;

	/* must perform manual padding */
	index = ctx->count & (bsize - 1);
	end = (index < bsize - plen) ? bsize : (2 * bsize);

	/* start pad with 1 */
	ctx->buf[index] = 0x80;
	index++;

	/* pad with zeros */
	memset(ctx->buf + index, 0x00, end - index - 8);

	/*
	 * Append message length. Well, SHA-512 wants a 128 bit length value,
	 * nevertheless we use u64, should be enough for now...
	 */
	bits = ctx->count * 8;
	memcpy(ctx->buf + end - 8, &bits, sizeof(bits));
	cpacf_kimd(ctx->func, ctx->state, ctx->buf, end);

	/* copy digest to out */
	memcpy(out, ctx->state, crypto_shash_digestsize(desc->tfm));
	/* wipe context */
	memset(ctx, 0, sizeof *ctx);

	return 0;
}
EXPORT_SYMBOL_GPL(s390_sha_final);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("s390 SHA cipher common functions");
Commit	Line	Data
604973f1 JG	1	/*
	2	* Cryptographic API.
	3	*
	4	* s390 generic implementation of the SHA Secure Hash Algorithms.
	5	*
	6	* Copyright IBM Corp. 2007
	7	* Author(s): Jan Glauber (jang@de.ibm.com)
	8	*
	9	* This program is free software; you can redistribute it and/or modify it
	10	* under the terms of the GNU General Public License as published by the Free
	11	* Software Foundation; either version 2 of the License, or (at your option)
	12	* any later version.
	13	*
	14	*/
	15
563f346d	16	#include <crypto/internal/hash.h>
3a4c5d59	17	#include <linux/module.h>
c7d4d259	18	#include <asm/cpacf.h>
604973f1	19	#include "sha.h"
604973f1	20
563f346d	21	int s390_sha_update(struct shash_desc desc, const u8 data, unsigned int len)
604973f1	22	{
563f346d HX	23	struct s390_sha_ctx *ctx = shash_desc_ctx(desc);
563f346d HX	24	unsigned int bsize = crypto_shash_blocksize(desc->tfm);
0177db01	25	unsigned int index, n;
604973f1 JG	26
	27	/* how much is already in the buffer? */
	28	index = ctx->count & (bsize - 1);
	29	ctx->count += len;
	30
	31	if ((index + len) < bsize)
	32	goto store;
	33
	34	/* process one stored block */
	35	if (index) {
	36	memcpy(ctx->buf + index, data, bsize - index);
0177db01	37	cpacf_kimd(ctx->func, ctx->state, ctx->buf, bsize);
604973f1 JG	38	data += bsize - index;
604973f1 JG	39	len -= bsize - index;
9d20b571	40	index = 0;
604973f1 JG	41	}
	42
	43	/* process as many blocks as possible */
	44	if (len >= bsize) {
0177db01 MS	45	n = len & ~(bsize - 1);
	46	cpacf_kimd(ctx->func, ctx->state, data, n);
	47	data += n;
	48	len -= n;
604973f1 JG	49	}
	50	store:
	51	if (len)
	52	memcpy(ctx->buf + index , data, len);
563f346d HX	53
563f346d HX	54	return 0;
604973f1 JG	55	}
	56	EXPORT_SYMBOL_GPL(s390_sha_update);
	57
563f346d	58	int s390_sha_final(struct shash_desc desc, u8 out)
604973f1	59	{
563f346d HX	60	struct s390_sha_ctx *ctx = shash_desc_ctx(desc);
563f346d HX	61	unsigned int bsize = crypto_shash_blocksize(desc->tfm);
604973f1	62	u64 bits;
291dc7c0	63	unsigned int index, end, plen;
604973f1	64
291dc7c0 JG	65	/* SHA-512 uses 128 bit padding length */
	66	plen = (bsize > SHA256_BLOCK_SIZE) ? 16 : 8;
	67
604973f1 JG	68	/* must perform manual padding */
604973f1 JG	69	index = ctx->count & (bsize - 1);
291dc7c0	70	end = (index < bsize - plen) ? bsize : (2 * bsize);
604973f1 JG	71
	72	/* start pad with 1 */
	73	ctx->buf[index] = 0x80;
	74	index++;
	75
	76	/* pad with zeros */
	77	memset(ctx->buf + index, 0x00, end - index - 8);
	78
291dc7c0	79	/*
1537a363	80	* Append message length. Well, SHA-512 wants a 128 bit length value,
291dc7c0 JG	81	* nevertheless we use u64, should be enough for now...
291dc7c0 JG	82	*/
604973f1 JG	83	bits = ctx->count * 8;
604973f1 JG	84	memcpy(ctx->buf + end - 8, &bits, sizeof(bits));
0177db01	85	cpacf_kimd(ctx->func, ctx->state, ctx->buf, end);
604973f1 JG	86
604973f1 JG	87	/* copy digest to out */
563f346d	88	memcpy(out, ctx->state, crypto_shash_digestsize(desc->tfm));
604973f1 JG	89	/* wipe context */
604973f1 JG	90	memset(ctx, 0, sizeof *ctx);
563f346d HX	91
563f346d HX	92	return 0;
604973f1 JG	93	}
	94	EXPORT_SYMBOL_GPL(s390_sha_final);
	95
	96	MODULE_LICENSE("GPL");
	97	MODULE_DESCRIPTION("s390 SHA cipher common functions");