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
16#include <crypto/internal/hash.h>
17#include <linux/module.h>
18#include "sha.h"
19#include "crypt_s390.h"
20
21int s390_sha_update(struct shash_desc *desc, const u8 *data, unsigned int len)
22{
23	struct s390_sha_ctx *ctx = shash_desc_ctx(desc);
24	unsigned int bsize = crypto_shash_blocksize(desc->tfm);
25	unsigned int index;
26	int ret;
27
28	/* how much is already in the buffer? */
29	index = ctx->count & (bsize - 1);
30	ctx->count += len;
31
32	if ((index + len) < bsize)
33		goto store;
34
35	/* process one stored block */
36	if (index) {
37		memcpy(ctx->buf + index, data, bsize - index);
38		ret = crypt_s390_kimd(ctx->func, ctx->state, ctx->buf, bsize);
39		if (ret != bsize)
40			return -EIO;
41		data += bsize - index;
42		len -= bsize - index;
43		index = 0;
44	}
45
46	/* process as many blocks as possible */
47	if (len >= bsize) {
48		ret = crypt_s390_kimd(ctx->func, ctx->state, data,
49				      len & ~(bsize - 1));
50		if (ret != (len & ~(bsize - 1)))
51			return -EIO;
52		data += ret;
53		len -= ret;
54	}
55store:
56	if (len)
57		memcpy(ctx->buf + index , data, len);
58
59	return 0;
60}
61EXPORT_SYMBOL_GPL(s390_sha_update);
62
63int s390_sha_final(struct shash_desc *desc, u8 *out)
64{
65	struct s390_sha_ctx *ctx = shash_desc_ctx(desc);
66	unsigned int bsize = crypto_shash_blocksize(desc->tfm);
67	u64 bits;
68	unsigned int index, end, plen;
69	int ret;
70
71	/* SHA-512 uses 128 bit padding length */
72	plen = (bsize > SHA256_BLOCK_SIZE) ? 16 : 8;
73
74	/* must perform manual padding */
75	index = ctx->count & (bsize - 1);
76	end = (index < bsize - plen) ? bsize : (2 * bsize);
77
78	/* start pad with 1 */
79	ctx->buf[index] = 0x80;
80	index++;
81
82	/* pad with zeros */
83	memset(ctx->buf + index, 0x00, end - index - 8);
84
85	/*
86	 * Append message length. Well, SHA-512 wants a 128 bit length value,
87	 * nevertheless we use u64, should be enough for now...
88	 */
89	bits = ctx->count * 8;
90	memcpy(ctx->buf + end - 8, &bits, sizeof(bits));
91
92	ret = crypt_s390_kimd(ctx->func, ctx->state, ctx->buf, end);
93	if (ret != end)
94		return -EIO;
95
96	/* copy digest to out */
97	memcpy(out, ctx->state, crypto_shash_digestsize(desc->tfm));
98	/* wipe context */
99	memset(ctx, 0, sizeof *ctx);
100
101	return 0;
102}
103EXPORT_SYMBOL_GPL(s390_sha_final);
104
105MODULE_LICENSE("GPL");
106MODULE_DESCRIPTION("s390 SHA cipher common functions");
107