Root/crypto/hash.c

1/*
2 * Cryptographic Hash operations.
3 *
4 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 */
11
12#include <crypto/internal/hash.h>
13#include <linux/errno.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/seq_file.h>
18
19#include "internal.h"
20
21static unsigned int crypto_hash_ctxsize(struct crypto_alg *alg, u32 type,
22                    u32 mask)
23{
24    return alg->cra_ctxsize;
25}
26
27static int hash_setkey_unaligned(struct crypto_hash *crt, const u8 *key,
28                         unsigned int keylen)
29{
30    struct crypto_tfm *tfm = crypto_hash_tfm(crt);
31    struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
32    unsigned long alignmask = crypto_hash_alignmask(crt);
33    int ret;
34    u8 *buffer, *alignbuffer;
35    unsigned long absize;
36
37    absize = keylen + alignmask;
38    buffer = kmalloc(absize, GFP_ATOMIC);
39    if (!buffer)
40        return -ENOMEM;
41
42    alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
43    memcpy(alignbuffer, key, keylen);
44    ret = alg->setkey(crt, alignbuffer, keylen);
45    memset(alignbuffer, 0, keylen);
46    kfree(buffer);
47    return ret;
48}
49
50static int hash_setkey(struct crypto_hash *crt, const u8 *key,
51               unsigned int keylen)
52{
53    struct crypto_tfm *tfm = crypto_hash_tfm(crt);
54    struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
55    unsigned long alignmask = crypto_hash_alignmask(crt);
56
57    if ((unsigned long)key & alignmask)
58        return hash_setkey_unaligned(crt, key, keylen);
59
60    return alg->setkey(crt, key, keylen);
61}
62
63static int hash_async_setkey(struct crypto_ahash *tfm_async, const u8 *key,
64            unsigned int keylen)
65{
66    struct crypto_tfm *tfm = crypto_ahash_tfm(tfm_async);
67    struct crypto_hash *tfm_hash = __crypto_hash_cast(tfm);
68    struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
69
70    return alg->setkey(tfm_hash, key, keylen);
71}
72
73static int hash_async_init(struct ahash_request *req)
74{
75    struct crypto_tfm *tfm = req->base.tfm;
76    struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
77    struct hash_desc desc = {
78        .tfm = __crypto_hash_cast(tfm),
79        .flags = req->base.flags,
80    };
81
82    return alg->init(&desc);
83}
84
85static int hash_async_update(struct ahash_request *req)
86{
87    struct crypto_tfm *tfm = req->base.tfm;
88    struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
89    struct hash_desc desc = {
90        .tfm = __crypto_hash_cast(tfm),
91        .flags = req->base.flags,
92    };
93
94    return alg->update(&desc, req->src, req->nbytes);
95}
96
97static int hash_async_final(struct ahash_request *req)
98{
99    struct crypto_tfm *tfm = req->base.tfm;
100    struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
101    struct hash_desc desc = {
102        .tfm = __crypto_hash_cast(tfm),
103        .flags = req->base.flags,
104    };
105
106    return alg->final(&desc, req->result);
107}
108
109static int hash_async_digest(struct ahash_request *req)
110{
111    struct crypto_tfm *tfm = req->base.tfm;
112    struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
113    struct hash_desc desc = {
114        .tfm = __crypto_hash_cast(tfm),
115        .flags = req->base.flags,
116    };
117
118    return alg->digest(&desc, req->src, req->nbytes, req->result);
119}
120
121static int crypto_init_hash_ops_async(struct crypto_tfm *tfm)
122{
123    struct ahash_tfm *crt = &tfm->crt_ahash;
124    struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
125
126    crt->init = hash_async_init;
127    crt->update = hash_async_update;
128    crt->final = hash_async_final;
129    crt->digest = hash_async_digest;
130    crt->setkey = hash_async_setkey;
131    crt->digestsize = alg->digestsize;
132
133    return 0;
134}
135
136static int crypto_init_hash_ops_sync(struct crypto_tfm *tfm)
137{
138    struct hash_tfm *crt = &tfm->crt_hash;
139    struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
140
141    crt->init = alg->init;
142    crt->update = alg->update;
143    crt->final = alg->final;
144    crt->digest = alg->digest;
145    crt->setkey = hash_setkey;
146    crt->digestsize = alg->digestsize;
147
148    return 0;
149}
150
151static int crypto_init_hash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
152{
153    struct hash_alg *alg = &tfm->__crt_alg->cra_hash;
154
155    if (alg->digestsize > PAGE_SIZE / 8)
156        return -EINVAL;
157
158    if ((mask & CRYPTO_ALG_TYPE_HASH_MASK) != CRYPTO_ALG_TYPE_HASH_MASK)
159        return crypto_init_hash_ops_async(tfm);
160    else
161        return crypto_init_hash_ops_sync(tfm);
162}
163
164static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)
165    __attribute__ ((unused));
166static void crypto_hash_show(struct seq_file *m, struct crypto_alg *alg)
167{
168    seq_printf(m, "type : hash\n");
169    seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
170    seq_printf(m, "digestsize : %u\n", alg->cra_hash.digestsize);
171}
172
173const struct crypto_type crypto_hash_type = {
174    .ctxsize = crypto_hash_ctxsize,
175    .init = crypto_init_hash_ops,
176#ifdef CONFIG_PROC_FS
177    .show = crypto_hash_show,
178#endif
179};
180EXPORT_SYMBOL_GPL(crypto_hash_type);
181
182MODULE_LICENSE("GPL");
183MODULE_DESCRIPTION("Generic cryptographic hash type");
184

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