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16#include <crypto/internal/hash.h>
17#include <crypto/scatterwalk.h>
18#include <linux/err.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/sched.h>
22#include <linux/slab.h>
23#include <linux/seq_file.h>
24
25#include "internal.h"
26
27static int hash_walk_next(struct crypto_hash_walk *walk)
28{
29 unsigned int alignmask = walk->alignmask;
30 unsigned int offset = walk->offset;
31 unsigned int nbytes = min(walk->entrylen,
32 ((unsigned int)(PAGE_SIZE)) - offset);
33
34 walk->data = crypto_kmap(walk->pg, 0);
35 walk->data += offset;
36
37 if (offset & alignmask)
38 nbytes = alignmask + 1 - (offset & alignmask);
39
40 walk->entrylen -= nbytes;
41 return nbytes;
42}
43
44static int hash_walk_new_entry(struct crypto_hash_walk *walk)
45{
46 struct scatterlist *sg;
47
48 sg = walk->sg;
49 walk->pg = sg_page(sg);
50 walk->offset = sg->offset;
51 walk->entrylen = sg->length;
52
53 if (walk->entrylen > walk->total)
54 walk->entrylen = walk->total;
55 walk->total -= walk->entrylen;
56
57 return hash_walk_next(walk);
58}
59
60int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
61{
62 unsigned int alignmask = walk->alignmask;
63 unsigned int nbytes = walk->entrylen;
64
65 walk->data -= walk->offset;
66
67 if (nbytes && walk->offset & alignmask && !err) {
68 walk->offset += alignmask - 1;
69 walk->offset = ALIGN(walk->offset, alignmask + 1);
70 walk->data += walk->offset;
71
72 nbytes = min(nbytes,
73 ((unsigned int)(PAGE_SIZE)) - walk->offset);
74 walk->entrylen -= nbytes;
75
76 return nbytes;
77 }
78
79 crypto_kunmap(walk->data, 0);
80 crypto_yield(walk->flags);
81
82 if (err)
83 return err;
84
85 walk->offset = 0;
86
87 if (nbytes)
88 return hash_walk_next(walk);
89
90 if (!walk->total)
91 return 0;
92
93 walk->sg = scatterwalk_sg_next(walk->sg);
94
95 return hash_walk_new_entry(walk);
96}
97EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
98
99int crypto_hash_walk_first(struct ahash_request *req,
100 struct crypto_hash_walk *walk)
101{
102 walk->total = req->nbytes;
103
104 if (!walk->total)
105 return 0;
106
107 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
108 walk->sg = req->src;
109 walk->flags = req->base.flags;
110
111 return hash_walk_new_entry(walk);
112}
113EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
114
115static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
116 unsigned int keylen)
117{
118 struct ahash_alg *ahash = crypto_ahash_alg(tfm);
119 unsigned long alignmask = crypto_ahash_alignmask(tfm);
120 int ret;
121 u8 *buffer, *alignbuffer;
122 unsigned long absize;
123
124 absize = keylen + alignmask;
125 buffer = kmalloc(absize, GFP_ATOMIC);
126 if (!buffer)
127 return -ENOMEM;
128
129 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
130 memcpy(alignbuffer, key, keylen);
131 ret = ahash->setkey(tfm, alignbuffer, keylen);
132 memset(alignbuffer, 0, keylen);
133 kfree(buffer);
134 return ret;
135}
136
137static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
138 unsigned int keylen)
139{
140 struct ahash_alg *ahash = crypto_ahash_alg(tfm);
141 unsigned long alignmask = crypto_ahash_alignmask(tfm);
142
143 if ((unsigned long)key & alignmask)
144 return ahash_setkey_unaligned(tfm, key, keylen);
145
146 return ahash->setkey(tfm, key, keylen);
147}
148
149static unsigned int crypto_ahash_ctxsize(struct crypto_alg *alg, u32 type,
150 u32 mask)
151{
152 return alg->cra_ctxsize;
153}
154
155static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
156{
157 struct ahash_alg *alg = &tfm->__crt_alg->cra_ahash;
158 struct ahash_tfm *crt = &tfm->crt_ahash;
159
160 if (alg->digestsize > PAGE_SIZE / 8)
161 return -EINVAL;
162
163 crt->init = alg->init;
164 crt->update = alg->update;
165 crt->final = alg->final;
166 crt->digest = alg->digest;
167 crt->setkey = ahash_setkey;
168 crt->digestsize = alg->digestsize;
169
170 return 0;
171}
172
173static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
174 __attribute__ ((unused));
175static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
176{
177 seq_printf(m, "type : ahash\n");
178 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
179 "yes" : "no");
180 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
181 seq_printf(m, "digestsize : %u\n", alg->cra_hash.digestsize);
182}
183
184const struct crypto_type crypto_ahash_type = {
185 .ctxsize = crypto_ahash_ctxsize,
186 .init = crypto_init_ahash_ops,
187#ifdef CONFIG_PROC_FS
188 .show = crypto_ahash_show,
189#endif
190};
191EXPORT_SYMBOL_GPL(crypto_ahash_type);
192
193MODULE_LICENSE("GPL");
194MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
195
