Linux 4.8-rc8
[linux/fpc-iii.git] / arch / s390 / crypto / sha_common.c
blob8e908166c3eec795e9315ded6467fc9721fe2189
1 /*
2 * Cryptographic API.
4 * s390 generic implementation of the SHA Secure Hash Algorithms.
6 * Copyright IBM Corp. 2007
7 * Author(s): Jan Glauber (jang@de.ibm.com)
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.
16 #include <crypto/internal/hash.h>
17 #include <linux/module.h>
18 #include <asm/cpacf.h>
19 #include "sha.h"
21 int s390_sha_update(struct shash_desc *desc, const u8 *data, unsigned int len)
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;
28 /* how much is already in the buffer? */
29 index = ctx->count & (bsize - 1);
30 ctx->count += len;
32 if ((index + len) < bsize)
33 goto store;
35 /* process one stored block */
36 if (index) {
37 memcpy(ctx->buf + index, data, bsize - index);
38 ret = cpacf_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;
46 /* process as many blocks as possible */
47 if (len >= bsize) {
48 ret = cpacf_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;
55 store:
56 if (len)
57 memcpy(ctx->buf + index , data, len);
59 return 0;
61 EXPORT_SYMBOL_GPL(s390_sha_update);
63 int s390_sha_final(struct shash_desc *desc, u8 *out)
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;
71 /* SHA-512 uses 128 bit padding length */
72 plen = (bsize > SHA256_BLOCK_SIZE) ? 16 : 8;
74 /* must perform manual padding */
75 index = ctx->count & (bsize - 1);
76 end = (index < bsize - plen) ? bsize : (2 * bsize);
78 /* start pad with 1 */
79 ctx->buf[index] = 0x80;
80 index++;
82 /* pad with zeros */
83 memset(ctx->buf + index, 0x00, end - index - 8);
86 * Append message length. Well, SHA-512 wants a 128 bit length value,
87 * nevertheless we use u64, should be enough for now...
89 bits = ctx->count * 8;
90 memcpy(ctx->buf + end - 8, &bits, sizeof(bits));
92 ret = cpacf_kimd(ctx->func, ctx->state, ctx->buf, end);
93 if (ret != end)
94 return -EIO;
96 /* copy digest to out */
97 memcpy(out, ctx->state, crypto_shash_digestsize(desc->tfm));
98 /* wipe context */
99 memset(ctx, 0, sizeof *ctx);
101 return 0;
103 EXPORT_SYMBOL_GPL(s390_sha_final);
105 MODULE_LICENSE("GPL");
106 MODULE_DESCRIPTION("s390 SHA cipher common functions");