1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * AMD Cryptographic Coprocessor (CCP) RSA crypto API support |
4 | * |
5 | * Copyright (C) 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/scatterlist.h> |
13 | #include <linux/crypto.h> |
14 | #include <crypto/algapi.h> |
15 | #include <crypto/internal/rsa.h> |
16 | #include <crypto/internal/akcipher.h> |
17 | #include <crypto/akcipher.h> |
18 | #include <crypto/scatterwalk.h> |
19 | |
20 | #include "ccp-crypto.h" |
21 | |
22 | static inline struct akcipher_request *akcipher_request_cast( |
23 | struct crypto_async_request *req) |
24 | { |
25 | return container_of(req, struct akcipher_request, base); |
26 | } |
27 | |
28 | static inline int ccp_copy_and_save_keypart(u8 **kpbuf, unsigned int *kplen, |
29 | const u8 *buf, size_t sz) |
30 | { |
31 | int nskip; |
32 | |
33 | for (nskip = 0; nskip < sz; nskip++) |
34 | if (buf[nskip]) |
35 | break; |
36 | *kplen = sz - nskip; |
37 | *kpbuf = kmemdup(p: buf + nskip, size: *kplen, GFP_KERNEL); |
38 | if (!*kpbuf) |
39 | return -ENOMEM; |
40 | |
41 | return 0; |
42 | } |
43 | |
44 | static int ccp_rsa_complete(struct crypto_async_request *async_req, int ret) |
45 | { |
46 | struct akcipher_request *req = akcipher_request_cast(req: async_req); |
47 | struct ccp_rsa_req_ctx *rctx = akcipher_request_ctx_dma(req); |
48 | |
49 | if (ret) |
50 | return ret; |
51 | |
52 | req->dst_len = rctx->cmd.u.rsa.key_size >> 3; |
53 | |
54 | return 0; |
55 | } |
56 | |
57 | static unsigned int ccp_rsa_maxsize(struct crypto_akcipher *tfm) |
58 | { |
59 | struct ccp_ctx *ctx = akcipher_tfm_ctx_dma(tfm); |
60 | |
61 | return ctx->u.rsa.n_len; |
62 | } |
63 | |
64 | static int ccp_rsa_crypt(struct akcipher_request *req, bool encrypt) |
65 | { |
66 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); |
67 | struct ccp_ctx *ctx = akcipher_tfm_ctx_dma(tfm); |
68 | struct ccp_rsa_req_ctx *rctx = akcipher_request_ctx_dma(req); |
69 | int ret = 0; |
70 | |
71 | memset(&rctx->cmd, 0, sizeof(rctx->cmd)); |
72 | INIT_LIST_HEAD(list: &rctx->cmd.entry); |
73 | rctx->cmd.engine = CCP_ENGINE_RSA; |
74 | |
75 | rctx->cmd.u.rsa.key_size = ctx->u.rsa.key_len; /* in bits */ |
76 | if (encrypt) { |
77 | rctx->cmd.u.rsa.exp = &ctx->u.rsa.e_sg; |
78 | rctx->cmd.u.rsa.exp_len = ctx->u.rsa.e_len; |
79 | } else { |
80 | rctx->cmd.u.rsa.exp = &ctx->u.rsa.d_sg; |
81 | rctx->cmd.u.rsa.exp_len = ctx->u.rsa.d_len; |
82 | } |
83 | rctx->cmd.u.rsa.mod = &ctx->u.rsa.n_sg; |
84 | rctx->cmd.u.rsa.mod_len = ctx->u.rsa.n_len; |
85 | rctx->cmd.u.rsa.src = req->src; |
86 | rctx->cmd.u.rsa.src_len = req->src_len; |
87 | rctx->cmd.u.rsa.dst = req->dst; |
88 | |
89 | ret = ccp_crypto_enqueue_request(req: &req->base, cmd: &rctx->cmd); |
90 | |
91 | return ret; |
92 | } |
93 | |
94 | static int ccp_rsa_encrypt(struct akcipher_request *req) |
95 | { |
96 | return ccp_rsa_crypt(req, encrypt: true); |
97 | } |
98 | |
99 | static int ccp_rsa_decrypt(struct akcipher_request *req) |
100 | { |
101 | return ccp_rsa_crypt(req, encrypt: false); |
102 | } |
103 | |
104 | static int ccp_check_key_length(unsigned int len) |
105 | { |
106 | /* In bits */ |
107 | if (len < 8 || len > 4096) |
108 | return -EINVAL; |
109 | return 0; |
110 | } |
111 | |
112 | static void ccp_rsa_free_key_bufs(struct ccp_ctx *ctx) |
113 | { |
114 | /* Clean up old key data */ |
115 | kfree_sensitive(objp: ctx->u.rsa.e_buf); |
116 | ctx->u.rsa.e_buf = NULL; |
117 | ctx->u.rsa.e_len = 0; |
118 | kfree_sensitive(objp: ctx->u.rsa.n_buf); |
119 | ctx->u.rsa.n_buf = NULL; |
120 | ctx->u.rsa.n_len = 0; |
121 | kfree_sensitive(objp: ctx->u.rsa.d_buf); |
122 | ctx->u.rsa.d_buf = NULL; |
123 | ctx->u.rsa.d_len = 0; |
124 | } |
125 | |
126 | static int ccp_rsa_setkey(struct crypto_akcipher *tfm, const void *key, |
127 | unsigned int keylen, bool private) |
128 | { |
129 | struct ccp_ctx *ctx = akcipher_tfm_ctx_dma(tfm); |
130 | struct rsa_key raw_key; |
131 | int ret; |
132 | |
133 | ccp_rsa_free_key_bufs(ctx); |
134 | memset(&raw_key, 0, sizeof(raw_key)); |
135 | |
136 | /* Code borrowed from crypto/rsa.c */ |
137 | if (private) |
138 | ret = rsa_parse_priv_key(rsa_key: &raw_key, key, key_len: keylen); |
139 | else |
140 | ret = rsa_parse_pub_key(rsa_key: &raw_key, key, key_len: keylen); |
141 | if (ret) |
142 | goto n_key; |
143 | |
144 | ret = ccp_copy_and_save_keypart(kpbuf: &ctx->u.rsa.n_buf, kplen: &ctx->u.rsa.n_len, |
145 | buf: raw_key.n, sz: raw_key.n_sz); |
146 | if (ret) |
147 | goto key_err; |
148 | sg_init_one(&ctx->u.rsa.n_sg, ctx->u.rsa.n_buf, ctx->u.rsa.n_len); |
149 | |
150 | ctx->u.rsa.key_len = ctx->u.rsa.n_len << 3; /* convert to bits */ |
151 | if (ccp_check_key_length(len: ctx->u.rsa.key_len)) { |
152 | ret = -EINVAL; |
153 | goto key_err; |
154 | } |
155 | |
156 | ret = ccp_copy_and_save_keypart(kpbuf: &ctx->u.rsa.e_buf, kplen: &ctx->u.rsa.e_len, |
157 | buf: raw_key.e, sz: raw_key.e_sz); |
158 | if (ret) |
159 | goto key_err; |
160 | sg_init_one(&ctx->u.rsa.e_sg, ctx->u.rsa.e_buf, ctx->u.rsa.e_len); |
161 | |
162 | if (private) { |
163 | ret = ccp_copy_and_save_keypart(kpbuf: &ctx->u.rsa.d_buf, |
164 | kplen: &ctx->u.rsa.d_len, |
165 | buf: raw_key.d, sz: raw_key.d_sz); |
166 | if (ret) |
167 | goto key_err; |
168 | sg_init_one(&ctx->u.rsa.d_sg, |
169 | ctx->u.rsa.d_buf, ctx->u.rsa.d_len); |
170 | } |
171 | |
172 | return 0; |
173 | |
174 | key_err: |
175 | ccp_rsa_free_key_bufs(ctx); |
176 | |
177 | n_key: |
178 | return ret; |
179 | } |
180 | |
181 | static int ccp_rsa_setprivkey(struct crypto_akcipher *tfm, const void *key, |
182 | unsigned int keylen) |
183 | { |
184 | return ccp_rsa_setkey(tfm, key, keylen, private: true); |
185 | } |
186 | |
187 | static int ccp_rsa_setpubkey(struct crypto_akcipher *tfm, const void *key, |
188 | unsigned int keylen) |
189 | { |
190 | return ccp_rsa_setkey(tfm, key, keylen, private: false); |
191 | } |
192 | |
193 | static int ccp_rsa_init_tfm(struct crypto_akcipher *tfm) |
194 | { |
195 | struct ccp_ctx *ctx = akcipher_tfm_ctx_dma(tfm); |
196 | |
197 | akcipher_set_reqsize_dma(akcipher: tfm, reqsize: sizeof(struct ccp_rsa_req_ctx)); |
198 | ctx->complete = ccp_rsa_complete; |
199 | |
200 | return 0; |
201 | } |
202 | |
203 | static void ccp_rsa_exit_tfm(struct crypto_akcipher *tfm) |
204 | { |
205 | struct ccp_ctx *ctx = akcipher_tfm_ctx_dma(tfm); |
206 | |
207 | ccp_rsa_free_key_bufs(ctx); |
208 | } |
209 | |
210 | static struct akcipher_alg ccp_rsa_defaults = { |
211 | .encrypt = ccp_rsa_encrypt, |
212 | .decrypt = ccp_rsa_decrypt, |
213 | .set_pub_key = ccp_rsa_setpubkey, |
214 | .set_priv_key = ccp_rsa_setprivkey, |
215 | .max_size = ccp_rsa_maxsize, |
216 | .init = ccp_rsa_init_tfm, |
217 | .exit = ccp_rsa_exit_tfm, |
218 | .base = { |
219 | .cra_name = "rsa" , |
220 | .cra_driver_name = "rsa-ccp" , |
221 | .cra_priority = CCP_CRA_PRIORITY, |
222 | .cra_module = THIS_MODULE, |
223 | .cra_ctxsize = 2 * sizeof(struct ccp_ctx) + CRYPTO_DMA_PADDING, |
224 | }, |
225 | }; |
226 | |
227 | struct ccp_rsa_def { |
228 | unsigned int version; |
229 | const char *name; |
230 | const char *driver_name; |
231 | unsigned int reqsize; |
232 | struct akcipher_alg *alg_defaults; |
233 | }; |
234 | |
235 | static struct ccp_rsa_def rsa_algs[] = { |
236 | { |
237 | .version = CCP_VERSION(3, 0), |
238 | .name = "rsa" , |
239 | .driver_name = "rsa-ccp" , |
240 | .reqsize = sizeof(struct ccp_rsa_req_ctx), |
241 | .alg_defaults = &ccp_rsa_defaults, |
242 | } |
243 | }; |
244 | |
245 | static int ccp_register_rsa_alg(struct list_head *head, |
246 | const struct ccp_rsa_def *def) |
247 | { |
248 | struct ccp_crypto_akcipher_alg *ccp_alg; |
249 | struct akcipher_alg *alg; |
250 | int ret; |
251 | |
252 | ccp_alg = kzalloc(size: sizeof(*ccp_alg), GFP_KERNEL); |
253 | if (!ccp_alg) |
254 | return -ENOMEM; |
255 | |
256 | INIT_LIST_HEAD(list: &ccp_alg->entry); |
257 | |
258 | alg = &ccp_alg->alg; |
259 | *alg = *def->alg_defaults; |
260 | snprintf(buf: alg->base.cra_name, CRYPTO_MAX_ALG_NAME, fmt: "%s" , def->name); |
261 | snprintf(buf: alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, fmt: "%s" , |
262 | def->driver_name); |
263 | ret = crypto_register_akcipher(alg); |
264 | if (ret) { |
265 | pr_err("%s akcipher algorithm registration error (%d)\n" , |
266 | alg->base.cra_name, ret); |
267 | kfree(objp: ccp_alg); |
268 | return ret; |
269 | } |
270 | |
271 | list_add(new: &ccp_alg->entry, head); |
272 | |
273 | return 0; |
274 | } |
275 | |
276 | int ccp_register_rsa_algs(struct list_head *head) |
277 | { |
278 | int i, ret; |
279 | unsigned int ccpversion = ccp_version(); |
280 | |
281 | /* Register the RSA algorithm in standard mode |
282 | * This works for CCP v3 and later |
283 | */ |
284 | for (i = 0; i < ARRAY_SIZE(rsa_algs); i++) { |
285 | if (rsa_algs[i].version > ccpversion) |
286 | continue; |
287 | ret = ccp_register_rsa_alg(head, def: &rsa_algs[i]); |
288 | if (ret) |
289 | return ret; |
290 | } |
291 | |
292 | return 0; |
293 | } |
294 | |