1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AMD Cryptographic Coprocessor (CCP) AES GCM crypto API support
4 *
5 * Copyright (C) 2016,2017 Advanced Micro Devices, Inc.
6 *
7 * Author: Gary R Hook <gary.hook@amd.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/sched.h>
12 #include <linux/delay.h>
13 #include <linux/scatterlist.h>
14 #include <linux/crypto.h>
15 #include <crypto/internal/aead.h>
16 #include <crypto/algapi.h>
17 #include <crypto/aes.h>
18 #include <crypto/ctr.h>
19 #include <crypto/gcm.h>
20 #include <crypto/scatterwalk.h>
21
22 #include "ccp-crypto.h"
23
ccp_aes_gcm_complete(struct crypto_async_request * async_req,int ret)24 static int ccp_aes_gcm_complete(struct crypto_async_request *async_req, int ret)
25 {
26 return ret;
27 }
28
ccp_aes_gcm_setkey(struct crypto_aead * tfm,const u8 * key,unsigned int key_len)29 static int ccp_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
30 unsigned int key_len)
31 {
32 struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
33
34 switch (key_len) {
35 case AES_KEYSIZE_128:
36 ctx->u.aes.type = CCP_AES_TYPE_128;
37 break;
38 case AES_KEYSIZE_192:
39 ctx->u.aes.type = CCP_AES_TYPE_192;
40 break;
41 case AES_KEYSIZE_256:
42 ctx->u.aes.type = CCP_AES_TYPE_256;
43 break;
44 default:
45 return -EINVAL;
46 }
47
48 ctx->u.aes.mode = CCP_AES_MODE_GCM;
49 ctx->u.aes.key_len = key_len;
50
51 memcpy(ctx->u.aes.key, key, key_len);
52 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
53
54 return 0;
55 }
56
ccp_aes_gcm_setauthsize(struct crypto_aead * tfm,unsigned int authsize)57 static int ccp_aes_gcm_setauthsize(struct crypto_aead *tfm,
58 unsigned int authsize)
59 {
60 switch (authsize) {
61 case 16:
62 case 15:
63 case 14:
64 case 13:
65 case 12:
66 case 8:
67 case 4:
68 break;
69 default:
70 return -EINVAL;
71 }
72
73 return 0;
74 }
75
ccp_aes_gcm_crypt(struct aead_request * req,bool encrypt)76 static int ccp_aes_gcm_crypt(struct aead_request *req, bool encrypt)
77 {
78 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
79 struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
80 struct ccp_aes_req_ctx *rctx = aead_request_ctx(req);
81 struct scatterlist *iv_sg = NULL;
82 unsigned int iv_len = 0;
83 int i;
84 int ret = 0;
85
86 if (!ctx->u.aes.key_len)
87 return -EINVAL;
88
89 if (ctx->u.aes.mode != CCP_AES_MODE_GCM)
90 return -EINVAL;
91
92 if (!req->iv)
93 return -EINVAL;
94
95 /*
96 * 5 parts:
97 * plaintext/ciphertext input
98 * AAD
99 * key
100 * IV
101 * Destination+tag buffer
102 */
103
104 /* Prepare the IV: 12 bytes + an integer (counter) */
105 memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE);
106 for (i = 0; i < 3; i++)
107 rctx->iv[i + GCM_AES_IV_SIZE] = 0;
108 rctx->iv[AES_BLOCK_SIZE - 1] = 1;
109
110 /* Set up a scatterlist for the IV */
111 iv_sg = &rctx->iv_sg;
112 iv_len = AES_BLOCK_SIZE;
113 sg_init_one(iv_sg, rctx->iv, iv_len);
114
115 /* The AAD + plaintext are concatenated in the src buffer */
116 memset(&rctx->cmd, 0, sizeof(rctx->cmd));
117 INIT_LIST_HEAD(&rctx->cmd.entry);
118 rctx->cmd.engine = CCP_ENGINE_AES;
119 rctx->cmd.u.aes.authsize = crypto_aead_authsize(tfm);
120 rctx->cmd.u.aes.type = ctx->u.aes.type;
121 rctx->cmd.u.aes.mode = ctx->u.aes.mode;
122 rctx->cmd.u.aes.action = encrypt;
123 rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
124 rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
125 rctx->cmd.u.aes.iv = iv_sg;
126 rctx->cmd.u.aes.iv_len = iv_len;
127 rctx->cmd.u.aes.src = req->src;
128 rctx->cmd.u.aes.src_len = req->cryptlen;
129 rctx->cmd.u.aes.aad_len = req->assoclen;
130
131 /* The cipher text + the tag are in the dst buffer */
132 rctx->cmd.u.aes.dst = req->dst;
133
134 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
135
136 return ret;
137 }
138
ccp_aes_gcm_encrypt(struct aead_request * req)139 static int ccp_aes_gcm_encrypt(struct aead_request *req)
140 {
141 return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_ENCRYPT);
142 }
143
ccp_aes_gcm_decrypt(struct aead_request * req)144 static int ccp_aes_gcm_decrypt(struct aead_request *req)
145 {
146 return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_DECRYPT);
147 }
148
ccp_aes_gcm_cra_init(struct crypto_aead * tfm)149 static int ccp_aes_gcm_cra_init(struct crypto_aead *tfm)
150 {
151 struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
152
153 ctx->complete = ccp_aes_gcm_complete;
154 ctx->u.aes.key_len = 0;
155
156 crypto_aead_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx));
157
158 return 0;
159 }
160
ccp_aes_gcm_cra_exit(struct crypto_tfm * tfm)161 static void ccp_aes_gcm_cra_exit(struct crypto_tfm *tfm)
162 {
163 }
164
165 static struct aead_alg ccp_aes_gcm_defaults = {
166 .setkey = ccp_aes_gcm_setkey,
167 .setauthsize = ccp_aes_gcm_setauthsize,
168 .encrypt = ccp_aes_gcm_encrypt,
169 .decrypt = ccp_aes_gcm_decrypt,
170 .init = ccp_aes_gcm_cra_init,
171 .ivsize = GCM_AES_IV_SIZE,
172 .maxauthsize = AES_BLOCK_SIZE,
173 .base = {
174 .cra_flags = CRYPTO_ALG_ASYNC |
175 CRYPTO_ALG_ALLOCATES_MEMORY |
176 CRYPTO_ALG_KERN_DRIVER_ONLY |
177 CRYPTO_ALG_NEED_FALLBACK,
178 .cra_blocksize = AES_BLOCK_SIZE,
179 .cra_ctxsize = sizeof(struct ccp_ctx),
180 .cra_priority = CCP_CRA_PRIORITY,
181 .cra_exit = ccp_aes_gcm_cra_exit,
182 .cra_module = THIS_MODULE,
183 },
184 };
185
186 struct ccp_aes_aead_def {
187 enum ccp_aes_mode mode;
188 unsigned int version;
189 const char *name;
190 const char *driver_name;
191 unsigned int blocksize;
192 unsigned int ivsize;
193 struct aead_alg *alg_defaults;
194 };
195
196 static struct ccp_aes_aead_def aes_aead_algs[] = {
197 {
198 .mode = CCP_AES_MODE_GHASH,
199 .version = CCP_VERSION(5, 0),
200 .name = "gcm(aes)",
201 .driver_name = "gcm-aes-ccp",
202 .blocksize = 1,
203 .ivsize = AES_BLOCK_SIZE,
204 .alg_defaults = &ccp_aes_gcm_defaults,
205 },
206 };
207
ccp_register_aes_aead(struct list_head * head,const struct ccp_aes_aead_def * def)208 static int ccp_register_aes_aead(struct list_head *head,
209 const struct ccp_aes_aead_def *def)
210 {
211 struct ccp_crypto_aead *ccp_aead;
212 struct aead_alg *alg;
213 int ret;
214
215 ccp_aead = kzalloc(sizeof(*ccp_aead), GFP_KERNEL);
216 if (!ccp_aead)
217 return -ENOMEM;
218
219 INIT_LIST_HEAD(&ccp_aead->entry);
220
221 ccp_aead->mode = def->mode;
222
223 /* Copy the defaults and override as necessary */
224 alg = &ccp_aead->alg;
225 *alg = *def->alg_defaults;
226 snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
227 snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
228 def->driver_name);
229 alg->base.cra_blocksize = def->blocksize;
230
231 ret = crypto_register_aead(alg);
232 if (ret) {
233 pr_err("%s aead algorithm registration error (%d)\n",
234 alg->base.cra_name, ret);
235 kfree(ccp_aead);
236 return ret;
237 }
238
239 list_add(&ccp_aead->entry, head);
240
241 return 0;
242 }
243
ccp_register_aes_aeads(struct list_head * head)244 int ccp_register_aes_aeads(struct list_head *head)
245 {
246 int i, ret;
247 unsigned int ccpversion = ccp_version();
248
249 for (i = 0; i < ARRAY_SIZE(aes_aead_algs); i++) {
250 if (aes_aead_algs[i].version > ccpversion)
251 continue;
252 ret = ccp_register_aes_aead(head, &aes_aead_algs[i]);
253 if (ret)
254 return ret;
255 }
256
257 return 0;
258 }
259