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
27static int ccp_aes_gcm_complete(struct crypto_async_request *async_req, int ret)
28{
29 return ret;
30}
31
32static 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
61static int ccp_aes_gcm_setauthsize(struct crypto_aead *tfm,
62 unsigned int authsize)
63{
64 return 0;
65}
66
67static int ccp_aes_gcm_crypt(struct aead_request *req, bool encrypt)
68{
69 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
70 struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
71 struct ccp_aes_req_ctx *rctx = aead_request_ctx(req);
72 struct scatterlist *iv_sg = NULL;
73 unsigned int iv_len = 0;
74 int i;
75 int ret = 0;
76
77 if (!ctx->u.aes.key_len)
78 return -EINVAL;
79
80 if (ctx->u.aes.mode != CCP_AES_MODE_GCM)
81 return -EINVAL;
82
83 if (!req->iv)
84 return -EINVAL;
85
86 /*
87 * 5 parts:
88 * plaintext/ciphertext input
89 * AAD
90 * key
91 * IV
92 * Destination+tag buffer
93 */
94
95 /* Prepare the IV: 12 bytes + an integer (counter) */
96 memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE);
97 for (i = 0; i < 3; i++)
98 rctx->iv[i + GCM_AES_IV_SIZE] = 0;
99 rctx->iv[AES_BLOCK_SIZE - 1] = 1;
100
101 /* Set up a scatterlist for the IV */
102 iv_sg = &rctx->iv_sg;
103 iv_len = AES_BLOCK_SIZE;
104 sg_init_one(iv_sg, rctx->iv, iv_len);
105
106 /* The AAD + plaintext are concatenated in the src buffer */
107 memset(&rctx->cmd, 0, sizeof(rctx->cmd));
108 INIT_LIST_HEAD(&rctx->cmd.entry);
109 rctx->cmd.engine = CCP_ENGINE_AES;
110 rctx->cmd.u.aes.type = ctx->u.aes.type;
111 rctx->cmd.u.aes.mode = ctx->u.aes.mode;
112 rctx->cmd.u.aes.action = encrypt;
113 rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
114 rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
115 rctx->cmd.u.aes.iv = iv_sg;
116 rctx->cmd.u.aes.iv_len = iv_len;
117 rctx->cmd.u.aes.src = req->src;
118 rctx->cmd.u.aes.src_len = req->cryptlen;
119 rctx->cmd.u.aes.aad_len = req->assoclen;
120
121 /* The cipher text + the tag are in the dst buffer */
122 rctx->cmd.u.aes.dst = req->dst;
123
124 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
125
126 return ret;
127}
128
129static int ccp_aes_gcm_encrypt(struct aead_request *req)
130{
131 return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_ENCRYPT);
132}
133
134static int ccp_aes_gcm_decrypt(struct aead_request *req)
135{
136 return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_DECRYPT);
137}
138
139static int ccp_aes_gcm_cra_init(struct crypto_aead *tfm)
140{
141 struct ccp_ctx *ctx = crypto_aead_ctx(tfm);
142
143 ctx->complete = ccp_aes_gcm_complete;
144 ctx->u.aes.key_len = 0;
145
146 crypto_aead_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx));
147
148 return 0;
149}
150
151static void ccp_aes_gcm_cra_exit(struct crypto_tfm *tfm)
152{
153}
154
155static struct aead_alg ccp_aes_gcm_defaults = {
156 .setkey = ccp_aes_gcm_setkey,
157 .setauthsize = ccp_aes_gcm_setauthsize,
158 .encrypt = ccp_aes_gcm_encrypt,
159 .decrypt = ccp_aes_gcm_decrypt,
160 .init = ccp_aes_gcm_cra_init,
161 .ivsize = GCM_AES_IV_SIZE,
162 .maxauthsize = AES_BLOCK_SIZE,
163 .base = {
164 .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER |
165 CRYPTO_ALG_ASYNC |
166 CRYPTO_ALG_KERN_DRIVER_ONLY |
167 CRYPTO_ALG_NEED_FALLBACK,
168 .cra_blocksize = AES_BLOCK_SIZE,
169 .cra_ctxsize = sizeof(struct ccp_ctx),
170 .cra_priority = CCP_CRA_PRIORITY,
171 .cra_type = &crypto_ablkcipher_type,
172 .cra_exit = ccp_aes_gcm_cra_exit,
173 .cra_module = THIS_MODULE,
174 },
175};
176
177struct ccp_aes_aead_def {
178 enum ccp_aes_mode mode;
179 unsigned int version;
180 const char *name;
181 const char *driver_name;
182 unsigned int blocksize;
183 unsigned int ivsize;
184 struct aead_alg *alg_defaults;
185};
186
187static struct ccp_aes_aead_def aes_aead_algs[] = {
188 {
189 .mode = CCP_AES_MODE_GHASH,
190 .version = CCP_VERSION(5, 0),
191 .name = "gcm(aes)",
192 .driver_name = "gcm-aes-ccp",
193 .blocksize = 1,
194 .ivsize = AES_BLOCK_SIZE,
195 .alg_defaults = &ccp_aes_gcm_defaults,
196 },
197};
198
199static int ccp_register_aes_aead(struct list_head *head,
200 const struct ccp_aes_aead_def *def)
201{
202 struct ccp_crypto_aead *ccp_aead;
203 struct aead_alg *alg;
204 int ret;
205
206 ccp_aead = kzalloc(sizeof(*ccp_aead), GFP_KERNEL);
207 if (!ccp_aead)
208 return -ENOMEM;
209
210 INIT_LIST_HEAD(&ccp_aead->entry);
211
212 ccp_aead->mode = def->mode;
213
214 /* Copy the defaults and override as necessary */
215 alg = &ccp_aead->alg;
216 *alg = *def->alg_defaults;
217 snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
218 snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
219 def->driver_name);
220 alg->base.cra_blocksize = def->blocksize;
221 alg->base.cra_ablkcipher.ivsize = def->ivsize;
222
223 ret = crypto_register_aead(alg);
224 if (ret) {
225 pr_err("%s ablkcipher algorithm registration error (%d)\n",
226 alg->base.cra_name, ret);
227 kfree(ccp_aead);
228 return ret;
229 }
230
231 list_add(&ccp_aead->entry, head);
232
233 return 0;
234}
235
236int ccp_register_aes_aeads(struct list_head *head)
237{
238 int i, ret;
239 unsigned int ccpversion = ccp_version();
240
241 for (i = 0; i < ARRAY_SIZE(aes_aead_algs); i++) {
242 if (aes_aead_algs[i].version > ccpversion)
243 continue;
244 ret = ccp_register_aes_aead(head, &aes_aead_algs[i]);
245 if (ret)
246 return ret;
247 }
248
249 return 0;
250}
251