1 /*
2 * AMD Cryptographic Coprocessor (CCP) AES GCM crypto API support
3 *
4 * Copyright (C) 2016,2017 Advanced Micro Devices, Inc.
5 *
6 * Author: Gary R Hook <gary.hook@amd.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/module.h>
14 #include <linux/sched.h>
15 #include <linux/delay.h>
16 #include <linux/scatterlist.h>
17 #include <linux/crypto.h>
18 #include <crypto/internal/aead.h>
19 #include <crypto/algapi.h>
20 #include <crypto/aes.h>
21 #include <crypto/ctr.h>
22 #include <crypto/gcm.h>
23 #include <crypto/scatterwalk.h>
24
25 #include "ccp-crypto.h"
26
ccp_aes_gcm_complete(struct crypto_async_request * async_req,int ret)27 static int ccp_aes_gcm_complete(struct crypto_async_request *async_req, int ret)
28 {
29 return ret;
30 }
31
ccp_aes_gcm_setkey(struct crypto_aead * tfm,const u8 * key,unsigned int key_len)32 static int ccp_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
33 unsigned int key_len)
34 {
35 struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
36
37 switch (key_len) {
38 case AES_KEYSIZE_128:
39 ctx->u.aes.type = CCP_AES_TYPE_128;
40 break;
41 case AES_KEYSIZE_192:
42 ctx->u.aes.type = CCP_AES_TYPE_192;
43 break;
44 case AES_KEYSIZE_256:
45 ctx->u.aes.type = CCP_AES_TYPE_256;
46 break;
47 default:
48 crypto_aead_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
49 return -EINVAL;
50 }
51
52 ctx->u.aes.mode = CCP_AES_MODE_GCM;
53 ctx->u.aes.key_len = key_len;
54
55 memcpy(ctx->u.aes.key, key, key_len);
56 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
57
58 return 0;
59 }
60
ccp_aes_gcm_setauthsize(struct crypto_aead * tfm,unsigned int authsize)61 static int ccp_aes_gcm_setauthsize(struct crypto_aead *tfm,
62 unsigned int authsize)
63 {
64 switch (authsize) {
65 case 16:
66 case 15:
67 case 14:
68 case 13:
69 case 12:
70 case 8:
71 case 4:
72 break;
73 default:
74 return -EINVAL;
75 }
76
77 return 0;
78 }
79
ccp_aes_gcm_crypt(struct aead_request * req,bool encrypt)80 static int ccp_aes_gcm_crypt(struct aead_request *req, bool encrypt)
81 {
82 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
83 struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
84 struct ccp_aes_req_ctx *rctx = aead_request_ctx(req);
85 struct scatterlist *iv_sg = NULL;
86 unsigned int iv_len = 0;
87 int i;
88 int ret = 0;
89
90 if (!ctx->u.aes.key_len)
91 return -EINVAL;
92
93 if (ctx->u.aes.mode != CCP_AES_MODE_GCM)
94 return -EINVAL;
95
96 if (!req->iv)
97 return -EINVAL;
98
99 /*
100 * 5 parts:
101 * plaintext/ciphertext input
102 * AAD
103 * key
104 * IV
105 * Destination+tag buffer
106 */
107
108 /* Prepare the IV: 12 bytes + an integer (counter) */
109 memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE);
110 for (i = 0; i < 3; i++)
111 rctx->iv[i + GCM_AES_IV_SIZE] = 0;
112 rctx->iv[AES_BLOCK_SIZE - 1] = 1;
113
114 /* Set up a scatterlist for the IV */
115 iv_sg = &rctx->iv_sg;
116 iv_len = AES_BLOCK_SIZE;
117 sg_init_one(iv_sg, rctx->iv, iv_len);
118
119 /* The AAD + plaintext are concatenated in the src buffer */
120 memset(&rctx->cmd, 0, sizeof(rctx->cmd));
121 INIT_LIST_HEAD(&rctx->cmd.entry);
122 rctx->cmd.engine = CCP_ENGINE_AES;
123 rctx->cmd.u.aes.authsize = crypto_aead_authsize(tfm);
124 rctx->cmd.u.aes.type = ctx->u.aes.type;
125 rctx->cmd.u.aes.mode = ctx->u.aes.mode;
126 rctx->cmd.u.aes.action = encrypt;
127 rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
128 rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
129 rctx->cmd.u.aes.iv = iv_sg;
130 rctx->cmd.u.aes.iv_len = iv_len;
131 rctx->cmd.u.aes.src = req->src;
132 rctx->cmd.u.aes.src_len = req->cryptlen;
133 rctx->cmd.u.aes.aad_len = req->assoclen;
134
135 /* The cipher text + the tag are in the dst buffer */
136 rctx->cmd.u.aes.dst = req->dst;
137
138 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
139
140 return ret;
141 }
142
ccp_aes_gcm_encrypt(struct aead_request * req)143 static int ccp_aes_gcm_encrypt(struct aead_request *req)
144 {
145 return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_ENCRYPT);
146 }
147
ccp_aes_gcm_decrypt(struct aead_request * req)148 static int ccp_aes_gcm_decrypt(struct aead_request *req)
149 {
150 return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_DECRYPT);
151 }
152
ccp_aes_gcm_cra_init(struct crypto_aead * tfm)153 static int ccp_aes_gcm_cra_init(struct crypto_aead *tfm)
154 {
155 struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
156
157 ctx->complete = ccp_aes_gcm_complete;
158 ctx->u.aes.key_len = 0;
159
160 crypto_aead_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx));
161
162 return 0;
163 }
164
ccp_aes_gcm_cra_exit(struct crypto_tfm * tfm)165 static void ccp_aes_gcm_cra_exit(struct crypto_tfm *tfm)
166 {
167 }
168
169 static struct aead_alg ccp_aes_gcm_defaults = {
170 .setkey = ccp_aes_gcm_setkey,
171 .setauthsize = ccp_aes_gcm_setauthsize,
172 .encrypt = ccp_aes_gcm_encrypt,
173 .decrypt = ccp_aes_gcm_decrypt,
174 .init = ccp_aes_gcm_cra_init,
175 .ivsize = GCM_AES_IV_SIZE,
176 .maxauthsize = AES_BLOCK_SIZE,
177 .base = {
178 .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER |
179 CRYPTO_ALG_ASYNC |
180 CRYPTO_ALG_KERN_DRIVER_ONLY |
181 CRYPTO_ALG_NEED_FALLBACK,
182 .cra_blocksize = AES_BLOCK_SIZE,
183 .cra_ctxsize = sizeof(struct ccp_ctx),
184 .cra_priority = CCP_CRA_PRIORITY,
185 .cra_type = &crypto_ablkcipher_type,
186 .cra_exit = ccp_aes_gcm_cra_exit,
187 .cra_module = THIS_MODULE,
188 },
189 };
190
191 struct ccp_aes_aead_def {
192 enum ccp_aes_mode mode;
193 unsigned int version;
194 const char *name;
195 const char *driver_name;
196 unsigned int blocksize;
197 unsigned int ivsize;
198 struct aead_alg *alg_defaults;
199 };
200
201 static struct ccp_aes_aead_def aes_aead_algs[] = {
202 {
203 .mode = CCP_AES_MODE_GHASH,
204 .version = CCP_VERSION(5, 0),
205 .name = "gcm(aes)",
206 .driver_name = "gcm-aes-ccp",
207 .blocksize = 1,
208 .ivsize = AES_BLOCK_SIZE,
209 .alg_defaults = &ccp_aes_gcm_defaults,
210 },
211 };
212
ccp_register_aes_aead(struct list_head * head,const struct ccp_aes_aead_def * def)213 static int ccp_register_aes_aead(struct list_head *head,
214 const struct ccp_aes_aead_def *def)
215 {
216 struct ccp_crypto_aead *ccp_aead;
217 struct aead_alg *alg;
218 int ret;
219
220 ccp_aead = kzalloc(sizeof(*ccp_aead), GFP_KERNEL);
221 if (!ccp_aead)
222 return -ENOMEM;
223
224 INIT_LIST_HEAD(&ccp_aead->entry);
225
226 ccp_aead->mode = def->mode;
227
228 /* Copy the defaults and override as necessary */
229 alg = &ccp_aead->alg;
230 *alg = *def->alg_defaults;
231 snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
232 snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
233 def->driver_name);
234 alg->base.cra_blocksize = def->blocksize;
235 alg->base.cra_ablkcipher.ivsize = def->ivsize;
236
237 ret = crypto_register_aead(alg);
238 if (ret) {
239 pr_err("%s ablkcipher algorithm registration error (%d)\n",
240 alg->base.cra_name, ret);
241 kfree(ccp_aead);
242 return ret;
243 }
244
245 list_add(&ccp_aead->entry, head);
246
247 return 0;
248 }
249
ccp_register_aes_aeads(struct list_head * head)250 int ccp_register_aes_aeads(struct list_head *head)
251 {
252 int i, ret;
253 unsigned int ccpversion = ccp_version();
254
255 for (i = 0; i < ARRAY_SIZE(aes_aead_algs); i++) {
256 if (aes_aead_algs[i].version > ccpversion)
257 continue;
258 ret = ccp_register_aes_aead(head, &aes_aead_algs[i]);
259 if (ret)
260 return ret;
261 }
262
263 return 0;
264 }
265