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Loc Ho004a4032008-05-14 20:41:47 +08001/*
2 * Asynchronous Cryptographic Hash operations.
3 *
4 * This is the asynchronous version of hash.c with notification of
5 * completion via a callback.
6 *
7 * Copyright (c) 2008 Loc Ho <lho@amcc.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
Herbert Xu20036252008-07-07 22:19:53 +080016#include <crypto/internal/hash.h>
17#include <crypto/scatterwalk.h>
Loc Ho004a4032008-05-14 20:41:47 +080018#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
Herbert Xu20036252008-07-07 22:19:53 +080027static 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
Herbert Xu5f7082e2008-08-31 22:21:09 +1000115int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
116 struct crypto_hash_walk *walk,
117 struct scatterlist *sg, unsigned int len)
118{
119 walk->total = len;
120
121 if (!walk->total)
122 return 0;
123
124 walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
125 walk->sg = sg;
126 walk->flags = hdesc->flags;
127
128 return hash_walk_new_entry(walk);
129}
130
Loc Ho004a4032008-05-14 20:41:47 +0800131static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
132 unsigned int keylen)
133{
134 struct ahash_alg *ahash = crypto_ahash_alg(tfm);
135 unsigned long alignmask = crypto_ahash_alignmask(tfm);
136 int ret;
137 u8 *buffer, *alignbuffer;
138 unsigned long absize;
139
140 absize = keylen + alignmask;
141 buffer = kmalloc(absize, GFP_ATOMIC);
142 if (!buffer)
143 return -ENOMEM;
144
145 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
146 memcpy(alignbuffer, key, keylen);
147 ret = ahash->setkey(tfm, alignbuffer, keylen);
148 memset(alignbuffer, 0, keylen);
149 kfree(buffer);
150 return ret;
151}
152
153static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
154 unsigned int keylen)
155{
156 struct ahash_alg *ahash = crypto_ahash_alg(tfm);
157 unsigned long alignmask = crypto_ahash_alignmask(tfm);
158
159 if ((unsigned long)key & alignmask)
160 return ahash_setkey_unaligned(tfm, key, keylen);
161
162 return ahash->setkey(tfm, key, keylen);
163}
164
Herbert Xu3751f402008-11-08 08:56:57 +0800165static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
166 unsigned int keylen)
167{
168 return -ENOSYS;
169}
170
Herbert Xudec8b782008-11-02 21:38:11 +0800171int crypto_ahash_import(struct ahash_request *req, const u8 *in)
172{
173 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
174 struct ahash_alg *alg = crypto_ahash_alg(tfm);
175
176 memcpy(ahash_request_ctx(req), in, crypto_ahash_reqsize(tfm));
177
178 if (alg->reinit)
179 alg->reinit(req);
180
181 return 0;
182}
183EXPORT_SYMBOL_GPL(crypto_ahash_import);
184
Loc Ho004a4032008-05-14 20:41:47 +0800185static unsigned int crypto_ahash_ctxsize(struct crypto_alg *alg, u32 type,
186 u32 mask)
187{
188 return alg->cra_ctxsize;
189}
190
191static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
192{
193 struct ahash_alg *alg = &tfm->__crt_alg->cra_ahash;
194 struct ahash_tfm *crt = &tfm->crt_ahash;
195
Herbert Xuca786dc2008-07-07 20:23:56 +0800196 if (alg->digestsize > PAGE_SIZE / 8)
Loc Ho004a4032008-05-14 20:41:47 +0800197 return -EINVAL;
198
199 crt->init = alg->init;
200 crt->update = alg->update;
201 crt->final = alg->final;
202 crt->digest = alg->digest;
Herbert Xu3751f402008-11-08 08:56:57 +0800203 crt->setkey = alg->setkey ? ahash_setkey : ahash_nosetkey;
Loc Ho004a4032008-05-14 20:41:47 +0800204 crt->digestsize = alg->digestsize;
205
206 return 0;
207}
208
209static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
210 __attribute__ ((unused));
211static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
212{
213 seq_printf(m, "type : ahash\n");
214 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
215 "yes" : "no");
216 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
217 seq_printf(m, "digestsize : %u\n", alg->cra_hash.digestsize);
218}
219
220const struct crypto_type crypto_ahash_type = {
221 .ctxsize = crypto_ahash_ctxsize,
222 .init = crypto_init_ahash_ops,
223#ifdef CONFIG_PROC_FS
224 .show = crypto_ahash_show,
225#endif
226};
227EXPORT_SYMBOL_GPL(crypto_ahash_type);
228
229MODULE_LICENSE("GPL");
230MODULE_DESCRIPTION("Asynchronous cryptographic hash type");