crypto: crc32c - Switch to shash
[linux-2.6.git] / crypto / digest.c
1 /*
2  * Cryptographic API.
3  *
4  * Digest operations.
5  *
6  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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 <crypto/scatterwalk.h>
17 #include <linux/mm.h>
18 #include <linux/errno.h>
19 #include <linux/hardirq.h>
20 #include <linux/highmem.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/scatterlist.h>
24
25 #include "internal.h"
26
27 static int init(struct hash_desc *desc)
28 {
29         struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
30
31         tfm->__crt_alg->cra_digest.dia_init(tfm);
32         return 0;
33 }
34
35 static int update2(struct hash_desc *desc,
36                    struct scatterlist *sg, unsigned int nbytes)
37 {
38         struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
39         unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
40
41         if (!nbytes)
42                 return 0;
43
44         for (;;) {
45                 struct page *pg = sg_page(sg);
46                 unsigned int offset = sg->offset;
47                 unsigned int l = sg->length;
48
49                 if (unlikely(l > nbytes))
50                         l = nbytes;
51                 nbytes -= l;
52
53                 do {
54                         unsigned int bytes_from_page = min(l, ((unsigned int)
55                                                            (PAGE_SIZE)) - 
56                                                            offset);
57                         char *src = crypto_kmap(pg, 0);
58                         char *p = src + offset;
59
60                         if (unlikely(offset & alignmask)) {
61                                 unsigned int bytes =
62                                         alignmask + 1 - (offset & alignmask);
63                                 bytes = min(bytes, bytes_from_page);
64                                 tfm->__crt_alg->cra_digest.dia_update(tfm, p,
65                                                                       bytes);
66                                 p += bytes;
67                                 bytes_from_page -= bytes;
68                                 l -= bytes;
69                         }
70                         tfm->__crt_alg->cra_digest.dia_update(tfm, p,
71                                                               bytes_from_page);
72                         crypto_kunmap(src, 0);
73                         crypto_yield(desc->flags);
74                         offset = 0;
75                         pg++;
76                         l -= bytes_from_page;
77                 } while (l > 0);
78
79                 if (!nbytes)
80                         break;
81                 sg = scatterwalk_sg_next(sg);
82         }
83
84         return 0;
85 }
86
87 static int update(struct hash_desc *desc,
88                   struct scatterlist *sg, unsigned int nbytes)
89 {
90         if (WARN_ON_ONCE(in_irq()))
91                 return -EDEADLK;
92         return update2(desc, sg, nbytes);
93 }
94
95 static int final(struct hash_desc *desc, u8 *out)
96 {
97         struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
98         unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
99         struct digest_alg *digest = &tfm->__crt_alg->cra_digest;
100
101         if (unlikely((unsigned long)out & alignmask)) {
102                 unsigned long align = alignmask + 1;
103                 unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);
104                 u8 *dst = (u8 *)ALIGN(addr, align) +
105                           ALIGN(tfm->__crt_alg->cra_ctxsize, align);
106
107                 digest->dia_final(tfm, dst);
108                 memcpy(out, dst, digest->dia_digestsize);
109         } else
110                 digest->dia_final(tfm, out);
111
112         return 0;
113 }
114
115 static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen)
116 {
117         crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK);
118         return -ENOSYS;
119 }
120
121 static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen)
122 {
123         struct crypto_tfm *tfm = crypto_hash_tfm(hash);
124
125         crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK);
126         return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen);
127 }
128
129 static int digest(struct hash_desc *desc,
130                   struct scatterlist *sg, unsigned int nbytes, u8 *out)
131 {
132         if (WARN_ON_ONCE(in_irq()))
133                 return -EDEADLK;
134
135         init(desc);
136         update2(desc, sg, nbytes);
137         return final(desc, out);
138 }
139
140 int crypto_init_digest_ops(struct crypto_tfm *tfm)
141 {
142         struct hash_tfm *ops = &tfm->crt_hash;
143         struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;
144
145         if (dalg->dia_digestsize > PAGE_SIZE / 8)
146                 return -EINVAL;
147         
148         ops->init       = init;
149         ops->update     = update;
150         ops->final      = final;
151         ops->digest     = digest;
152         ops->setkey     = dalg->dia_setkey ? setkey : nosetkey;
153         ops->digestsize = dalg->dia_digestsize;
154         
155         return 0;
156 }
157
158 void crypto_exit_digest_ops(struct crypto_tfm *tfm)
159 {
160 }
161
162 static int digest_async_nosetkey(struct crypto_ahash *tfm_async, const u8 *key,
163                         unsigned int keylen)
164 {
165         crypto_ahash_clear_flags(tfm_async, CRYPTO_TFM_RES_MASK);
166         return -ENOSYS;
167 }
168
169 static int digest_async_setkey(struct crypto_ahash *tfm_async, const u8 *key,
170                         unsigned int keylen)
171 {
172         struct crypto_tfm    *tfm        = crypto_ahash_tfm(tfm_async);
173         struct digest_alg    *dalg       = &tfm->__crt_alg->cra_digest;
174
175         crypto_ahash_clear_flags(tfm_async, CRYPTO_TFM_RES_MASK);
176         return dalg->dia_setkey(tfm, key, keylen);
177 }
178
179 static int digest_async_init(struct ahash_request *req)
180 {
181         struct crypto_tfm *tfm  = req->base.tfm;
182         struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;
183
184         dalg->dia_init(tfm);
185         return 0;
186 }
187
188 static int digest_async_update(struct ahash_request *req)
189 {
190         struct crypto_tfm *tfm = req->base.tfm;
191         struct hash_desc  desc = {
192                 .tfm   = __crypto_hash_cast(tfm),
193                 .flags = req->base.flags,
194         };
195
196         update(&desc, req->src, req->nbytes);
197         return 0;
198 }
199
200 static int digest_async_final(struct ahash_request *req)
201 {
202         struct crypto_tfm *tfm  = req->base.tfm;
203         struct hash_desc  desc = {
204                 .tfm   = __crypto_hash_cast(tfm),
205                 .flags = req->base.flags,
206         };
207
208         final(&desc, req->result);
209         return 0;
210 }
211
212 static int digest_async_digest(struct ahash_request *req)
213 {
214         struct crypto_tfm *tfm  = req->base.tfm;
215         struct hash_desc  desc = {
216                 .tfm   = __crypto_hash_cast(tfm),
217                 .flags = req->base.flags,
218         };
219
220         return digest(&desc, req->src, req->nbytes, req->result);
221 }
222
223 int crypto_init_digest_ops_async(struct crypto_tfm *tfm)
224 {
225         struct ahash_tfm  *crt  = &tfm->crt_ahash;
226         struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;
227
228         if (dalg->dia_digestsize > PAGE_SIZE / 8)
229                 return -EINVAL;
230
231         crt->init       = digest_async_init;
232         crt->update     = digest_async_update;
233         crt->final      = digest_async_final;
234         crt->digest     = digest_async_digest;
235         crt->setkey     = dalg->dia_setkey ? digest_async_setkey :
236                                                 digest_async_nosetkey;
237         crt->digestsize = dalg->dia_digestsize;
238
239         return 0;
240 }