1/*
2 * Glue code for MD5 implementation for PPC assembler
3 *
4 * Based on generic implementation.
5 *
6 * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15#include <crypto/internal/hash.h>
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/mm.h>
19#include <linux/cryptohash.h>
20#include <linux/types.h>
21#include <crypto/md5.h>
22#include <asm/byteorder.h>
23
24extern void ppc_md5_transform(u32 *state, const u8 *src, u32 blocks);
25
26static inline void ppc_md5_clear_context(struct md5_state *sctx)
27{
28	int count = sizeof(struct md5_state) >> 2;
29	u32 *ptr = (u32 *)sctx;
30
31	/* make sure we can clear the fast way */
32	BUILD_BUG_ON(sizeof(struct md5_state) % 4);
33	do { *ptr++ = 0; } while (--count);
34}
35
36static int ppc_md5_init(struct shash_desc *desc)
37{
38	struct md5_state *sctx = shash_desc_ctx(desc);
39
40	sctx->hash[0] = 0x67452301;
41	sctx->hash[1] = 0xefcdab89;
42	sctx->hash[2] = 0x98badcfe;
43	sctx->hash[3] =	0x10325476;
44	sctx->byte_count = 0;
45
46	return 0;
47}
48
49static int ppc_md5_update(struct shash_desc *desc, const u8 *data,
50			unsigned int len)
51{
52	struct md5_state *sctx = shash_desc_ctx(desc);
53	const unsigned int offset = sctx->byte_count & 0x3f;
54	unsigned int avail = 64 - offset;
55	const u8 *src = data;
56
57	sctx->byte_count += len;
58
59	if (avail > len) {
60		memcpy((char *)sctx->block + offset, src, len);
61		return 0;
62	}
63
64	if (offset) {
65		memcpy((char *)sctx->block + offset, src, avail);
66		ppc_md5_transform(sctx->hash, (const u8 *)sctx->block, 1);
67		len -= avail;
68		src += avail;
69	}
70
71	if (len > 63) {
72		ppc_md5_transform(sctx->hash, src, len >> 6);
73		src += len & ~0x3f;
74		len &= 0x3f;
75	}
76
77	memcpy((char *)sctx->block, src, len);
78	return 0;
79}
80
81static int ppc_md5_final(struct shash_desc *desc, u8 *out)
82{
83	struct md5_state *sctx = shash_desc_ctx(desc);
84	const unsigned int offset = sctx->byte_count & 0x3f;
85	const u8 *src = (const u8 *)sctx->block;
86	u8 *p = (u8 *)src + offset;
87	int padlen = 55 - offset;
88	__le64 *pbits = (__le64 *)((char *)sctx->block + 56);
89	__le32 *dst = (__le32 *)out;
90
91	*p++ = 0x80;
92
93	if (padlen < 0) {
94		memset(p, 0x00, padlen + sizeof (u64));
95		ppc_md5_transform(sctx->hash, src, 1);
96		p = (char *)sctx->block;
97		padlen = 56;
98	}
99
100	memset(p, 0, padlen);
101	*pbits = cpu_to_le64(sctx->byte_count << 3);
102	ppc_md5_transform(sctx->hash, src, 1);
103
104	dst[0] = cpu_to_le32(sctx->hash[0]);
105	dst[1] = cpu_to_le32(sctx->hash[1]);
106	dst[2] = cpu_to_le32(sctx->hash[2]);
107	dst[3] = cpu_to_le32(sctx->hash[3]);
108
109	ppc_md5_clear_context(sctx);
110	return 0;
111}
112
113static int ppc_md5_export(struct shash_desc *desc, void *out)
114{
115	struct md5_state *sctx = shash_desc_ctx(desc);
116
117	memcpy(out, sctx, sizeof(*sctx));
118	return 0;
119}
120
121static int ppc_md5_import(struct shash_desc *desc, const void *in)
122{
123	struct md5_state *sctx = shash_desc_ctx(desc);
124
125	memcpy(sctx, in, sizeof(*sctx));
126	return 0;
127}
128
129static struct shash_alg alg = {
130	.digestsize	=	MD5_DIGEST_SIZE,
131	.init		=	ppc_md5_init,
132	.update		=	ppc_md5_update,
133	.final		=	ppc_md5_final,
134	.export		=	ppc_md5_export,
135	.import		=	ppc_md5_import,
136	.descsize	=	sizeof(struct md5_state),
137	.statesize	=	sizeof(struct md5_state),
138	.base		=	{
139		.cra_name	=	"md5",
140		.cra_driver_name=	"md5-ppc",
141		.cra_priority	=	200,
142		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
143		.cra_blocksize	=	MD5_HMAC_BLOCK_SIZE,
144		.cra_module	=	THIS_MODULE,
145	}
146};
147
148static int __init ppc_md5_mod_init(void)
149{
150	return crypto_register_shash(&alg);
151}
152
153static void __exit ppc_md5_mod_fini(void)
154{
155	crypto_unregister_shash(&alg);
156}
157
158module_init(ppc_md5_mod_init);
159module_exit(ppc_md5_mod_fini);
160
161MODULE_LICENSE("GPL");
162MODULE_DESCRIPTION("MD5 Secure Hash Algorithm, PPC assembler");
163
164MODULE_ALIAS_CRYPTO("md5");
165MODULE_ALIAS_CRYPTO("md5-ppc");
166