xref: /optee_os/ta/pkcs11/src/token_capabilities.c (revision a1d5c81f8834a9d2c6f4372cce2e59e70e709121)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (c) 2017-2020, Linaro Limited
4  */
5 
6 #include <assert.h>
7 #include <pkcs11_ta.h>
8 #include <string.h>
9 #include <util.h>
10 #include <tee_api.h>
11 #include <tee_internal_api_extensions.h>
12 
13 #include "pkcs11_helpers.h"
14 #include "token_capabilities.h"
15 
16 #define ALLOWED_PKCS11_CKFM	\
17 	(PKCS11_CKFM_ENCRYPT | PKCS11_CKFM_DECRYPT |		\
18 	 PKCS11_CKFM_DERIVE | PKCS11_CKFM_DIGEST |		\
19 	 PKCS11_CKFM_SIGN | PKCS11_CKFM_SIGN_RECOVER |		\
20 	 PKCS11_CKFM_VERIFY | PKCS11_CKFM_VERIFY_RECOVER |	\
21 	 PKCS11_CKFM_GENERATE |	PKCS11_CKFM_GENERATE_KEY_PAIR |	\
22 	 PKCS11_CKFM_WRAP | PKCS11_CKFM_UNWRAP)
23 
24 /*
25  * Definition of supported processings for a PKCS#11 mechanisms
26  * @id: Mechanism ID
27  * @flags: Valid PKCS11_CKFM_* for a mechanism as per PKCS#11
28  * @one_shot: true of mechanism can be used for a one-short processing
29  * @string: Helper string of the mechanism ID for debug purpose
30  */
31 struct pkcs11_mechachism_modes {
32 	uint32_t id;
33 	uint32_t flags;
34 	bool one_shot;
35 #if CFG_TEE_TA_LOG_LEVEL > 0
36 	const char *string;
37 #endif
38 };
39 
40 #if CFG_TEE_TA_LOG_LEVEL > 0
41 #define MECHANISM(_label, _flags, _single_part)	\
42 	{					\
43 		.id = _label,			\
44 		.one_shot = (_single_part),	\
45 		.flags = (_flags),		\
46 		.string = #_label,		\
47 	}
48 #else
49 #define MECHANISM(_label, _flags, _single_part)	\
50 	{					\
51 		.id = _label,			\
52 		.one_shot = (_single_part),	\
53 		.flags = (_flags),		\
54 	}
55 #endif
56 
57 #define SINGLE_PART_ONLY	true
58 #define ANY_PART		false
59 
60 #define CKFM_CIPHER		(PKCS11_CKFM_ENCRYPT | PKCS11_CKFM_DECRYPT)
61 #define CKFM_WRAP_UNWRAP	(PKCS11_CKFM_WRAP | PKCS11_CKFM_UNWRAP)
62 #define CKFM_CIPHER_WRAP	(CKFM_CIPHER | CKFM_WRAP_UNWRAP)
63 #define CKFM_CIPHER_WRAP_DERIVE	(CKFM_CIPHER_WRAP | PKCS11_CKFM_DERIVE)
64 #define CKFM_AUTH_NO_RECOVER	(PKCS11_CKFM_SIGN | PKCS11_CKFM_VERIFY)
65 #define CKFM_AUTH_WITH_RECOVER	(PKCS11_CKFM_SIGN_RECOVER | \
66 				 PKCS11_CKFM_VERIFY_RECOVER)
67 
68 /* PKCS#11 specificies permitted operation for each mechanism  */
69 static const struct pkcs11_mechachism_modes pkcs11_modes[] = {
70 	/* AES */
71 	MECHANISM(PKCS11_CKM_AES_ECB, CKFM_CIPHER_WRAP, ANY_PART),
72 	MECHANISM(PKCS11_CKM_AES_CBC, CKFM_CIPHER_WRAP, ANY_PART),
73 	MECHANISM(PKCS11_CKM_AES_CBC_PAD, CKFM_CIPHER_WRAP, ANY_PART),
74 	MECHANISM(PKCS11_CKM_AES_CTS, CKFM_CIPHER_WRAP, ANY_PART),
75 	MECHANISM(PKCS11_CKM_AES_CTR, CKFM_CIPHER_WRAP, ANY_PART),
76 	MECHANISM(PKCS11_CKM_AES_ECB_ENCRYPT_DATA, PKCS11_CKFM_DERIVE,
77 		  ANY_PART),
78 	MECHANISM(PKCS11_CKM_AES_CBC_ENCRYPT_DATA, PKCS11_CKFM_DERIVE,
79 		  ANY_PART),
80 	MECHANISM(PKCS11_CKM_AES_KEY_GEN, PKCS11_CKFM_GENERATE, ANY_PART),
81 };
82 
83 #if CFG_TEE_TA_LOG_LEVEL > 0
84 const char *mechanism_string_id(enum pkcs11_mechanism_id id)
85 {
86 	const size_t offset = sizeof("PKCS11_CKM_") - 1;
87 	size_t n = 0;
88 
89 	for (n = 0; n < ARRAY_SIZE(pkcs11_modes); n++)
90 		if (pkcs11_modes[n].id == id)
91 			return pkcs11_modes[n].string + offset;
92 
93 	return "Unknown ID";
94 }
95 #endif /*CFG_TEE_TA_LOG_LEVEL*/
96 
97 /*
98  * Return true if @id is a valid mechanism ID
99  */
100 bool mechanism_is_valid(enum pkcs11_mechanism_id id)
101 {
102 	size_t n = 0;
103 
104 	for (n = 0; n < ARRAY_SIZE(pkcs11_modes); n++)
105 		if (id == pkcs11_modes[n].id)
106 			return true;
107 
108 	return false;
109 }
110 
111 /*
112  * Return true if mechanism ID is valid and flags matches PKCS#11 compliancy
113  */
114 bool __maybe_unused mechanism_flags_complies_pkcs11(uint32_t mechanism_type,
115 						    uint32_t flags)
116 {
117 	size_t n = 0;
118 
119 	assert((flags & ~ALLOWED_PKCS11_CKFM) == 0);
120 
121 	for (n = 0; n < ARRAY_SIZE(pkcs11_modes); n++) {
122 		if (pkcs11_modes[n].id == mechanism_type) {
123 			if (flags & ~pkcs11_modes[n].flags)
124 				EMSG("%s flags: 0x%"PRIx32" vs 0x%"PRIx32,
125 				     id2str_mechanism(mechanism_type),
126 				     flags, pkcs11_modes[n].flags);
127 
128 			return (flags & ~pkcs11_modes[n].flags) == 0;
129 		}
130 	}
131 
132 	/* Mechanism ID unexpectedly not found */
133 	return false;
134 }
135 
136 bool mechanism_is_one_shot_only(uint32_t mechanism_type)
137 {
138 	size_t n = 0;
139 
140 	for (n = 0; n < ARRAY_SIZE(pkcs11_modes); n++)
141 		if (pkcs11_modes[n].id == mechanism_type)
142 			return pkcs11_modes[n].one_shot;
143 
144 	/* Mechanism ID unexpectedly not found */
145 	TEE_Panic(PKCS11_RV_NOT_FOUND);
146 	/* Dummy return to keep compiler happy */
147 	return false;
148 }
149 
150 /*
151  * Field single_part_only is unused from array token_mechanism[], hence
152  * simply use ANY_PART for all mechanism there.
153  */
154 #define TA_MECHANISM(_label, _flags)	MECHANISM((_label), (_flags), ANY_PART)
155 
156 /*
157  * Arrays that centralizes the IDs and processing flags for mechanisms
158  * supported by each embedded token. Currently none.
159  */
160 const struct pkcs11_mechachism_modes token_mechanism[] = {
161 	TA_MECHANISM(PKCS11_CKM_AES_ECB, CKFM_CIPHER),
162 	TA_MECHANISM(PKCS11_CKM_AES_CBC, CKFM_CIPHER),
163 	TA_MECHANISM(PKCS11_CKM_AES_CBC_PAD, CKFM_CIPHER),
164 	TA_MECHANISM(PKCS11_CKM_AES_CTR, CKFM_CIPHER),
165 	TA_MECHANISM(PKCS11_CKM_AES_CTS, CKFM_CIPHER),
166 	TA_MECHANISM(PKCS11_CKM_AES_ECB_ENCRYPT_DATA, PKCS11_CKFM_DERIVE),
167 	TA_MECHANISM(PKCS11_CKM_AES_CBC_ENCRYPT_DATA, PKCS11_CKFM_DERIVE),
168 };
169 
170 /*
171  * tee_malloc_mechanism_array - Allocate and fill array of supported mechanisms
172  * @count: [in] [out] Pointer to number of mechanism IDs in client resource
173  * Return allocated array of the supported mechanism IDs
174  *
175  * Allocates array with 32bit cells mechanism IDs for the supported ones only
176  * if *@count covers number mechanism IDs exposed.
177  */
178 uint32_t *tee_malloc_mechanism_list(size_t *out_count)
179 {
180 	size_t n = 0;
181 	size_t count = 0;
182 	uint32_t *array = NULL;
183 
184 	for (n = 0; n < ARRAY_SIZE(token_mechanism); n++)
185 		if (token_mechanism[n].flags)
186 			count++;
187 
188 	if (*out_count >= count)
189 		array = TEE_Malloc(count * sizeof(*array),
190 				   TEE_USER_MEM_HINT_NO_FILL_ZERO);
191 
192 	*out_count = count;
193 
194 	if (!array)
195 		return NULL;
196 
197 	for (n = 0; n < ARRAY_SIZE(token_mechanism); n++) {
198 		if (token_mechanism[n].flags) {
199 			count--;
200 			array[count] = token_mechanism[n].id;
201 		}
202 	}
203 	assert(!count);
204 
205 	return array;
206 }
207 
208 uint32_t mechanism_supported_flags(enum pkcs11_mechanism_id id)
209 {
210 	size_t n = 0;
211 
212 	for (n = 0; n < ARRAY_SIZE(token_mechanism); n++) {
213 		if (id == token_mechanism[n].id) {
214 			uint32_t flags = token_mechanism[n].flags;
215 
216 			assert(mechanism_flags_complies_pkcs11(id, flags));
217 			return flags;
218 		}
219 	}
220 
221 	return 0;
222 }
223 
224 void mechanism_supported_key_sizes(uint32_t proc_id, uint32_t *min_key_size,
225 				   uint32_t *max_key_size)
226 {
227 	switch (proc_id) {
228 	case PKCS11_CKM_AES_KEY_GEN:
229 	case PKCS11_CKM_AES_ECB:
230 	case PKCS11_CKM_AES_CBC:
231 	case PKCS11_CKM_AES_CBC_PAD:
232 	case PKCS11_CKM_AES_CTR:
233 	case PKCS11_CKM_AES_CTS:
234 		*min_key_size = 16;
235 		*max_key_size = 32;
236 		break;
237 	default:
238 		*min_key_size = 0;
239 		*max_key_size = 0;
240 		break;
241 	}
242 }
243