1 /*
2 * FPU: Wrapper for blkcipher touching fpu
3 *
4 * Copyright (c) Intel Corp.
5 * Author: Huang Ying <ying.huang@intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the Free
9 * Software Foundation; either version 2 of the License, or (at your option)
10 * any later version.
11 *
12 */
13
14 #include <crypto/algapi.h>
15 #include <linux/err.h>
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/crypto.h>
21 #include <asm/fpu/api.h>
22
23 struct crypto_fpu_ctx {
24 struct crypto_blkcipher *child;
25 };
26
crypto_fpu_setkey(struct crypto_tfm * parent,const u8 * key,unsigned int keylen)27 static int crypto_fpu_setkey(struct crypto_tfm *parent, const u8 *key,
28 unsigned int keylen)
29 {
30 struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(parent);
31 struct crypto_blkcipher *child = ctx->child;
32 int err;
33
34 crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
35 crypto_blkcipher_set_flags(child, crypto_tfm_get_flags(parent) &
36 CRYPTO_TFM_REQ_MASK);
37 err = crypto_blkcipher_setkey(child, key, keylen);
38 crypto_tfm_set_flags(parent, crypto_blkcipher_get_flags(child) &
39 CRYPTO_TFM_RES_MASK);
40 return err;
41 }
42
crypto_fpu_encrypt(struct blkcipher_desc * desc_in,struct scatterlist * dst,struct scatterlist * src,unsigned int nbytes)43 static int crypto_fpu_encrypt(struct blkcipher_desc *desc_in,
44 struct scatterlist *dst, struct scatterlist *src,
45 unsigned int nbytes)
46 {
47 int err;
48 struct crypto_fpu_ctx *ctx = crypto_blkcipher_ctx(desc_in->tfm);
49 struct crypto_blkcipher *child = ctx->child;
50 struct blkcipher_desc desc = {
51 .tfm = child,
52 .info = desc_in->info,
53 .flags = desc_in->flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
54 };
55
56 kernel_fpu_begin();
57 err = crypto_blkcipher_crt(desc.tfm)->encrypt(&desc, dst, src, nbytes);
58 kernel_fpu_end();
59 return err;
60 }
61
crypto_fpu_decrypt(struct blkcipher_desc * desc_in,struct scatterlist * dst,struct scatterlist * src,unsigned int nbytes)62 static int crypto_fpu_decrypt(struct blkcipher_desc *desc_in,
63 struct scatterlist *dst, struct scatterlist *src,
64 unsigned int nbytes)
65 {
66 int err;
67 struct crypto_fpu_ctx *ctx = crypto_blkcipher_ctx(desc_in->tfm);
68 struct crypto_blkcipher *child = ctx->child;
69 struct blkcipher_desc desc = {
70 .tfm = child,
71 .info = desc_in->info,
72 .flags = desc_in->flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
73 };
74
75 kernel_fpu_begin();
76 err = crypto_blkcipher_crt(desc.tfm)->decrypt(&desc, dst, src, nbytes);
77 kernel_fpu_end();
78 return err;
79 }
80
crypto_fpu_init_tfm(struct crypto_tfm * tfm)81 static int crypto_fpu_init_tfm(struct crypto_tfm *tfm)
82 {
83 struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
84 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
85 struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(tfm);
86 struct crypto_blkcipher *cipher;
87
88 cipher = crypto_spawn_blkcipher(spawn);
89 if (IS_ERR(cipher))
90 return PTR_ERR(cipher);
91
92 ctx->child = cipher;
93 return 0;
94 }
95
crypto_fpu_exit_tfm(struct crypto_tfm * tfm)96 static void crypto_fpu_exit_tfm(struct crypto_tfm *tfm)
97 {
98 struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(tfm);
99 crypto_free_blkcipher(ctx->child);
100 }
101
crypto_fpu_alloc(struct rtattr ** tb)102 static struct crypto_instance *crypto_fpu_alloc(struct rtattr **tb)
103 {
104 struct crypto_instance *inst;
105 struct crypto_alg *alg;
106 int err;
107
108 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
109 if (err)
110 return ERR_PTR(err);
111
112 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
113 CRYPTO_ALG_TYPE_MASK);
114 if (IS_ERR(alg))
115 return ERR_CAST(alg);
116
117 inst = crypto_alloc_instance("fpu", alg);
118 if (IS_ERR(inst))
119 goto out_put_alg;
120
121 inst->alg.cra_flags = alg->cra_flags;
122 inst->alg.cra_priority = alg->cra_priority;
123 inst->alg.cra_blocksize = alg->cra_blocksize;
124 inst->alg.cra_alignmask = alg->cra_alignmask;
125 inst->alg.cra_type = alg->cra_type;
126 inst->alg.cra_blkcipher.ivsize = alg->cra_blkcipher.ivsize;
127 inst->alg.cra_blkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
128 inst->alg.cra_blkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
129 inst->alg.cra_ctxsize = sizeof(struct crypto_fpu_ctx);
130 inst->alg.cra_init = crypto_fpu_init_tfm;
131 inst->alg.cra_exit = crypto_fpu_exit_tfm;
132 inst->alg.cra_blkcipher.setkey = crypto_fpu_setkey;
133 inst->alg.cra_blkcipher.encrypt = crypto_fpu_encrypt;
134 inst->alg.cra_blkcipher.decrypt = crypto_fpu_decrypt;
135
136 out_put_alg:
137 crypto_mod_put(alg);
138 return inst;
139 }
140
crypto_fpu_free(struct crypto_instance * inst)141 static void crypto_fpu_free(struct crypto_instance *inst)
142 {
143 crypto_drop_spawn(crypto_instance_ctx(inst));
144 kfree(inst);
145 }
146
147 static struct crypto_template crypto_fpu_tmpl = {
148 .name = "fpu",
149 .alloc = crypto_fpu_alloc,
150 .free = crypto_fpu_free,
151 .module = THIS_MODULE,
152 };
153
crypto_fpu_init(void)154 int __init crypto_fpu_init(void)
155 {
156 return crypto_register_template(&crypto_fpu_tmpl);
157 }
158
crypto_fpu_exit(void)159 void crypto_fpu_exit(void)
160 {
161 crypto_unregister_template(&crypto_fpu_tmpl);
162 }
163
164 MODULE_ALIAS_CRYPTO("fpu");
165