1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Glue code for MD5 implementation for PPC assembler
4 *
5 * Based on generic implementation.
6 *
7 * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
8 */
9
10 #include <crypto/internal/hash.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/mm.h>
14 #include <linux/types.h>
15 #include <crypto/md5.h>
16 #include <asm/byteorder.h>
17
18 extern void ppc_md5_transform(u32 *state, const u8 *src, u32 blocks);
19
20 static inline void ppc_md5_clear_context(struct md5_state *sctx)
21 {
22 int count = sizeof(struct md5_state) >> 2;
23 u32 *ptr = (u32 *)sctx;
24
25 /* make sure we can clear the fast way */
26 BUILD_BUG_ON(sizeof(struct md5_state) % 4);
27 do { *ptr++ = 0; } while (--count);
28 }
29
30 static int ppc_md5_init(struct shash_desc *desc)
31 {
32 struct md5_state *sctx = shash_desc_ctx(desc);
33
34 sctx->hash[0] = MD5_H0;
35 sctx->hash[1] = MD5_H1;
36 sctx->hash[2] = MD5_H2;
37 sctx->hash[3] = MD5_H3;
38 sctx->byte_count = 0;
39
40 return 0;
41 }
42
43 static int ppc_md5_update(struct shash_desc *desc, const u8 *data,
44 unsigned int len)
45 {
46 struct md5_state *sctx = shash_desc_ctx(desc);
47 const unsigned int offset = sctx->byte_count & 0x3f;
48 unsigned int avail = 64 - offset;
49 const u8 *src = data;
50
51 sctx->byte_count += len;
52
53 if (avail > len) {
54 memcpy((char *)sctx->block + offset, src, len);
55 return 0;
56 }
57
58 if (offset) {
59 memcpy((char *)sctx->block + offset, src, avail);
60 ppc_md5_transform(sctx->hash, (const u8 *)sctx->block, 1);
61 len -= avail;
62 src += avail;
63 }
64
65 if (len > 63) {
66 ppc_md5_transform(sctx->hash, src, len >> 6);
67 src += len & ~0x3f;
68 len &= 0x3f;
69 }
70
71 memcpy((char *)sctx->block, src, len);
72 return 0;
73 }
74
75 static int ppc_md5_final(struct shash_desc *desc, u8 *out)
76 {
77 struct md5_state *sctx = shash_desc_ctx(desc);
78 const unsigned int offset = sctx->byte_count & 0x3f;
79 const u8 *src = (const u8 *)sctx->block;
80 u8 *p = (u8 *)src + offset;
81 int padlen = 55 - offset;
82 __le64 *pbits = (__le64 *)((char *)sctx->block + 56);
83 __le32 *dst = (__le32 *)out;
84
85 *p++ = 0x80;
86
87 if (padlen < 0) {
88 memset(p, 0x00, padlen + sizeof (u64));
89 ppc_md5_transform(sctx->hash, src, 1);
90 p = (char *)sctx->block;
91 padlen = 56;
92 }
93
94 memset(p, 0, padlen);
95 *pbits = cpu_to_le64(sctx->byte_count << 3);
96 ppc_md5_transform(sctx->hash, src, 1);
97
98 dst[0] = cpu_to_le32(sctx->hash[0]);
99 dst[1] = cpu_to_le32(sctx->hash[1]);
100 dst[2] = cpu_to_le32(sctx->hash[2]);
101 dst[3] = cpu_to_le32(sctx->hash[3]);
102
103 ppc_md5_clear_context(sctx);
104 return 0;
105 }
106
107 static int ppc_md5_export(struct shash_desc *desc, void *out)
108 {
109 struct md5_state *sctx = shash_desc_ctx(desc);
110
111 memcpy(out, sctx, sizeof(*sctx));
112 return 0;
113 }
114
115 static int ppc_md5_import(struct shash_desc *desc, const void *in)
116 {
117 struct md5_state *sctx = shash_desc_ctx(desc);
118
119 memcpy(sctx, in, sizeof(*sctx));
120 return 0;
121 }
122
123 static struct shash_alg alg = {
124 .digestsize = MD5_DIGEST_SIZE,
125 .init = ppc_md5_init,
126 .update = ppc_md5_update,
127 .final = ppc_md5_final,
128 .export = ppc_md5_export,
129 .import = ppc_md5_import,
130 .descsize = sizeof(struct md5_state),
131 .statesize = sizeof(struct md5_state),
132 .base = {
133 .cra_name = "md5",
134 .cra_driver_name= "md5-ppc",
135 .cra_priority = 200,
136 .cra_blocksize = MD5_HMAC_BLOCK_SIZE,
137 .cra_module = THIS_MODULE,
138 }
139 };
140
141 static int __init ppc_md5_mod_init(void)
142 {
143 return crypto_register_shash(&alg);
144 }
145
146 static void __exit ppc_md5_mod_fini(void)
147 {
148 crypto_unregister_shash(&alg);
149 }
150
151 module_init(ppc_md5_mod_init);
152 module_exit(ppc_md5_mod_fini);
153
154 MODULE_LICENSE("GPL");
155 MODULE_DESCRIPTION("MD5 Secure Hash Algorithm, PPC assembler");
156
157 MODULE_ALIAS_CRYPTO("md5");
158 MODULE_ALIAS_CRYPTO("md5-ppc");
159
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