xref: /optee_os/ta/pkcs11/src/persistent_token.c (revision bef8bc684207124e10d768c25fdf398db52610cf)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2018-2020, Linaro Limited
4  */
5 
6 #include <assert.h>
7 #include <pkcs11_ta.h>
8 #include <string.h>
9 #include <string_ext.h>
10 #include <tee_internal_api_extensions.h>
11 #include <util.h>
12 
13 #include "pkcs11_token.h"
14 #include "pkcs11_helpers.h"
15 
16 #define PERSISTENT_OBJECT_ID_LEN	32
17 
18 /*
19  * Token persistent objects
20  */
21 static TEE_Result get_db_file_name(struct ck_token *token,
22 				   char *name, size_t size)
23 {
24 	int n = snprintf(name, size, "token.db.%u", get_token_id(token));
25 
26 	if (n < 0 || (size_t)n >= size)
27 		return TEE_ERROR_SECURITY;
28 	else
29 		return TEE_SUCCESS;
30 }
31 
32 static TEE_Result open_db_file(struct ck_token *token,
33 			       TEE_ObjectHandle *out_hdl)
34 {
35 	char file[PERSISTENT_OBJECT_ID_LEN] = { };
36 	TEE_Result res = TEE_ERROR_GENERIC;
37 
38 	res = get_db_file_name(token, file, sizeof(file));
39 	if (res)
40 		return res;
41 
42 	return TEE_OpenPersistentObject(TEE_STORAGE_PRIVATE, file, sizeof(file),
43 					TEE_DATA_FLAG_ACCESS_READ |
44 					TEE_DATA_FLAG_ACCESS_WRITE,
45 					out_hdl);
46 }
47 
48 static TEE_Result get_pin_file_name(struct ck_token *token,
49 				    enum pkcs11_user_type user,
50 				    char *name, size_t size)
51 {
52 	int n = snprintf(name, size,
53 			 "token.db.%u-pin%d", get_token_id(token), user);
54 
55 	if (n < 0 || (size_t)n >= size)
56 		return TEE_ERROR_SECURITY;
57 	else
58 		return TEE_SUCCESS;
59 }
60 
61 static TEE_Result open_pin_file(struct ck_token *token,
62 				enum pkcs11_user_type user,
63 				TEE_ObjectHandle *out_hdl)
64 {
65 	char file[PERSISTENT_OBJECT_ID_LEN] = { };
66 	TEE_Result res = TEE_ERROR_GENERIC;
67 
68 	res = get_pin_file_name(token, user, file, sizeof(file));
69 	if (res)
70 		return res;
71 
72 	return TEE_OpenPersistentObject(TEE_STORAGE_PRIVATE, file, sizeof(file),
73 					0, out_hdl);
74 }
75 
76 static enum pkcs11_rc do_hash(uint32_t user, const uint8_t *pin,
77 			      size_t pin_size, uint32_t salt,
78 			      uint8_t hash[TEE_MAX_HASH_SIZE])
79 {
80 	TEE_Result res = TEE_SUCCESS;
81 	TEE_OperationHandle oh = TEE_HANDLE_NULL;
82 	uint32_t sz = TEE_MAX_HASH_SIZE;
83 
84 	res = TEE_AllocateOperation(&oh, TEE_ALG_SHA256, TEE_MODE_DIGEST, 0);
85 	if (res)
86 		return tee2pkcs_error(res);
87 
88 	TEE_DigestUpdate(oh, &user, sizeof(user));
89 	TEE_DigestUpdate(oh, &salt, sizeof(salt));
90 	res = TEE_DigestDoFinal(oh, pin, pin_size, hash, &sz);
91 	TEE_FreeOperation(oh);
92 
93 	if (res)
94 		return PKCS11_CKR_GENERAL_ERROR;
95 
96 	memset(hash + sz, 0, TEE_MAX_HASH_SIZE - sz);
97 	return PKCS11_CKR_OK;
98 }
99 
100 enum pkcs11_rc hash_pin(enum pkcs11_user_type user, const uint8_t *pin,
101 			size_t pin_size, uint32_t *salt,
102 			uint8_t hash[TEE_MAX_HASH_SIZE])
103 {
104 	enum pkcs11_rc rc = PKCS11_CKR_OK;
105 	uint32_t s = 0;
106 
107 	TEE_GenerateRandom(&s, sizeof(s));
108 	if (!s)
109 		s++;
110 
111 	rc = do_hash(user, pin, pin_size, s, hash);
112 	if (!rc)
113 		*salt = s;
114 	return rc;
115 }
116 
117 enum pkcs11_rc verify_pin(enum pkcs11_user_type user, const uint8_t *pin,
118 			  size_t pin_size, uint32_t salt,
119 			  const uint8_t hash[TEE_MAX_HASH_SIZE])
120 {
121 	uint8_t tmp_hash[TEE_MAX_HASH_SIZE] = { 0 };
122 	enum pkcs11_rc rc = PKCS11_CKR_OK;
123 
124 	rc = do_hash(user, pin, pin_size, salt, tmp_hash);
125 	if (rc)
126 		return rc;
127 
128 	if (buf_compare_ct(tmp_hash, hash, TEE_MAX_HASH_SIZE))
129 		rc = PKCS11_CKR_PIN_INCORRECT;
130 
131 	return rc;
132 }
133 
134 static void init_pin_keys(struct ck_token *token, enum pkcs11_user_type user)
135 {
136 	TEE_Result res = TEE_ERROR_GENERIC;
137 	TEE_ObjectHandle key_hdl = TEE_HANDLE_NULL;
138 
139 	res = open_pin_file(token, user, &key_hdl);
140 
141 	if (res == TEE_SUCCESS)
142 		DMSG("PIN key found");
143 
144 	if (res == TEE_ERROR_ITEM_NOT_FOUND) {
145 		TEE_Attribute attr = { };
146 		TEE_ObjectHandle hdl = TEE_HANDLE_NULL;
147 		uint8_t pin_key[16] = { };
148 		char file[PERSISTENT_OBJECT_ID_LEN] = { };
149 
150 		TEE_MemFill(&attr, 0, sizeof(attr));
151 
152 		TEE_GenerateRandom(pin_key, sizeof(pin_key));
153 		TEE_InitRefAttribute(&attr, TEE_ATTR_SECRET_VALUE,
154 				     pin_key, sizeof(pin_key));
155 
156 		res = TEE_AllocateTransientObject(TEE_TYPE_AES, 128, &hdl);
157 		if (res)
158 			TEE_Panic(0);
159 
160 		res = TEE_PopulateTransientObject(hdl, &attr, 1);
161 		if (res)
162 			TEE_Panic(0);
163 
164 		res = get_pin_file_name(token, user, file, sizeof(file));
165 		if (res)
166 			TEE_Panic(0);
167 
168 		res = TEE_CreatePersistentObject(TEE_STORAGE_PRIVATE,
169 						 file, sizeof(file), 0, hdl,
170 						 pin_key, sizeof(pin_key),
171 						 &key_hdl);
172 		TEE_CloseObject(hdl);
173 
174 		if (res == TEE_SUCCESS)
175 			DMSG("Token %u: PIN key created", get_token_id(token));
176 	}
177 
178 	if (res)
179 		TEE_Panic(res);
180 
181 	TEE_CloseObject(key_hdl);
182 }
183 
184 /*
185  * Release resources relate to persistent database
186  */
187 void close_persistent_db(struct ck_token *token __unused)
188 {
189 }
190 
191 /*
192  * Return the token instance, either initialized from reset or initialized
193  * from the token persistent state if found.
194  */
195 struct ck_token *init_persistent_db(unsigned int token_id)
196 {
197 	struct ck_token *token = get_token(token_id);
198 	TEE_Result res = TEE_ERROR_GENERIC;
199 	TEE_ObjectHandle db_hdl = TEE_HANDLE_NULL;
200 	/* Copy persistent database: main db and object db */
201 	struct token_persistent_main *db_main = NULL;
202 
203 	if (!token)
204 		return NULL;
205 
206 	init_pin_keys(token, PKCS11_CKU_SO);
207 	init_pin_keys(token, PKCS11_CKU_USER);
208 	COMPILE_TIME_ASSERT(PKCS11_CKU_SO == 0 && PKCS11_CKU_USER == 1 &&
209 			    PKCS11_MAX_USERS >= 2);
210 
211 	db_main = TEE_Malloc(sizeof(*db_main), TEE_MALLOC_FILL_ZERO);
212 	if (!db_main)
213 		goto error;
214 
215 	res = open_db_file(token, &db_hdl);
216 
217 	if (res == TEE_SUCCESS) {
218 		uint32_t size = 0;
219 
220 		IMSG("PKCS11 token %u: load db", token_id);
221 
222 		size = sizeof(*db_main);
223 		res = TEE_ReadObjectData(db_hdl, db_main, size, &size);
224 		if (res || size != sizeof(*db_main))
225 			TEE_Panic(0);
226 	} else if (res == TEE_ERROR_ITEM_NOT_FOUND) {
227 		char file[PERSISTENT_OBJECT_ID_LEN] = { };
228 
229 		IMSG("PKCS11 token %u: init db", token_id);
230 
231 		TEE_MemFill(db_main, 0, sizeof(*db_main));
232 		TEE_MemFill(db_main->label, '*', sizeof(db_main->label));
233 
234 		db_main->flags = PKCS11_CKFT_SO_PIN_TO_BE_CHANGED |
235 				 PKCS11_CKFT_USER_PIN_TO_BE_CHANGED |
236 				 PKCS11_CKFT_RNG |
237 				 PKCS11_CKFT_DUAL_CRYPTO_OPERATIONS |
238 				 PKCS11_CKFT_LOGIN_REQUIRED;
239 
240 		res = get_db_file_name(token, file, sizeof(file));
241 		if (res)
242 			TEE_Panic(0);
243 
244 		res = TEE_CreatePersistentObject(TEE_STORAGE_PRIVATE,
245 						 file, sizeof(file),
246 						 TEE_DATA_FLAG_ACCESS_READ |
247 						 TEE_DATA_FLAG_ACCESS_WRITE,
248 						 TEE_HANDLE_NULL,
249 						 db_main, sizeof(*db_main),
250 						 &db_hdl);
251 		if (res) {
252 			EMSG("Failed to create db: %"PRIx32, res);
253 			goto error;
254 		}
255 	} else {
256 		goto error;
257 	}
258 
259 	token->db_main = db_main;
260 	TEE_CloseObject(db_hdl);
261 
262 	return token;
263 
264 error:
265 	TEE_Free(db_main);
266 	if (db_hdl != TEE_HANDLE_NULL)
267 		TEE_CloseObject(db_hdl);
268 
269 	return NULL;
270 }
271