xref: /btstack/src/btstack_crypto.h (revision 10e0e23cd214c502fc7675df0fa338876b508fb3)
1 /*
2  * Copyright (C) 2017 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 /*
39  * btstack_crypto.h
40  *
41  * Central place for all crypto-related functions with completion callbacks to allow
42  * using of MCU crypto peripherals or the Bluetooth controller
43  */
44 
45 #ifndef __BTSTACK_CTRYPTO_H
46 #define __BTSTACK_CTRYPTO_H
47 
48 #include "btstack_defines.h"
49 
50 #if defined __cplusplus
51 extern "C" {
52 #endif
53 
54 #define CMAC_TEMP_API
55 
56 typedef enum {
57 	BTSTACK_CRYPTO_RANDOM,
58 	BTSTACK_CRYPTO_AES128,
59 	BTSTACK_CRYPTO_CMAC_GENERATOR,
60 	BTSTACK_CRYPTO_CMAC_MESSAGE,
61 	BTSTACK_CRYPTO_ECC_P256_GENERATE_KEY,
62 	BTSTACK_CRYPTO_ECC_P256_CALCULATE_DHKEY,
63 	BTSTACK_CRYPTO_CCM_ENCRYPT_BLOCK,
64 	BTSTACK_CRYPTO_CCM_DECRYPT_BLOCK,
65 } btstack_crypto_operation_t;
66 
67 typedef struct {
68 	btstack_context_callback_registration_t context_callback;
69 	btstack_crypto_operation_t              operation;
70 } btstack_crypto_t;
71 
72 typedef struct {
73 	btstack_crypto_t btstack_crypto;
74 	uint8_t  * buffer;
75 	uint16_t   size;
76 } btstack_crypto_random_t;
77 
78 typedef struct {
79 	btstack_crypto_t btstack_crypto;
80 	const uint8_t  * key;
81 	const uint8_t  * plaintext;
82 	uint8_t  * ciphertext;
83 } btstack_crypto_aes128_t;
84 
85 typedef struct {
86 	btstack_crypto_t btstack_crypto;
87 	const uint8_t  * key;
88 	uint16_t         size;
89 	union {
90 		uint8_t (*get_byte_callback)(uint16_t pos);
91 		const uint8_t * message;
92 	} data;
93 	uint8_t  * hash;
94 } btstack_crypto_aes128_cmac_t;
95 
96 typedef struct {
97 	btstack_crypto_t btstack_crypto;
98 	uint8_t * public_key;
99     uint8_t * dhkey;
100 } btstack_crypto_ecc_p256_t;
101 
102 typedef enum {
103     CCM_CALCULATE_X1,
104     CCM_W4_X1,
105     CCM_CALCULATE_XN,
106     CCM_W4_XN,
107     CCM_CALCULATE_S0,
108     CCM_W4_S0,
109     CCM_CALCULATE_SN,
110     CCM_W4_SN,
111 } btstack_crypto_ccm_state_t;
112 
113 typedef struct {
114 	btstack_crypto_t btstack_crypto;
115 	btstack_crypto_ccm_state_t state;
116 	const uint8_t * key;
117 	const uint8_t * nonce;
118 	const uint8_t * input;
119 	uint8_t       * output;
120 	uint8_t         x_i[16];
121 	uint16_t        message_len;
122 	uint16_t        block_len;
123 	uint16_t        counter;
124 	uint8_t         auth_len;
125 } btstack_crypto_ccm_t;
126 
127 /**
128  * Initialize crypto functions
129  */
130 void btstack_crypto_init(void);
131 
132 /**
133  * Generate random data
134  * @param request
135  * @param buffer for output
136  * @param size of requested random data
137  * @param callback
138  * @param callback_arg
139  * @note request needs to stay avaliable until callback (i.e. not provided on stack)
140  */
141 void btstack_crypto_random_generate(btstack_crypto_random_t * request, uint8_t * buffer, uint16_t size, void (* callback)(void * arg), void * callback_arg);
142 
143 /**
144  * Encrypt plaintext using AES128
145  * @param request
146  * @param key (16 bytes)
147  * @param plaintext (16 bytes)
148  * @param ciphertext (16 bytes)
149  * @param callback
150  * @param callback_arg
151  * @note request needs to stay avaliable until callback (i.e. not provided on stack)
152  */
153 void btstack_crypto_aes128_encrypt(btstack_crypto_aes128_t * request, const uint8_t * key, const uint8_t * plaintext, uint8_t * ciphertext, void (* callback)(void * arg), void * callback_arg);
154 
155 /**
156  * Calculate Cipher-based Message Authentication Code (CMAC) using AES128 and a generator function to provide data
157  * @param request
158  * @param key (16 bytes)
159  * @param size of message
160  * @param generator provides byte at requested position
161  * @param callback
162  * @param callback_arg
163  */
164 void btstack_crypto_aes128_cmac_generator(btstack_crypto_aes128_cmac_t * request, const uint8_t * key, uint16_t size, uint8_t (*get_byte_callback)(uint16_t pos), uint8_t * hash, void (* callback)(void * arg), void * callback_arg);
165 
166 /**
167  * Calculate Cipher-based Message Authentication Code (CMAC) using AES128 and complete message
168  * @param request
169  * @param key (16 bytes)
170  * @param len of message
171  * @param message
172  * @param hash result
173  * @param callback
174  * @param callback_arg
175  */
176 void btstack_crypto_aes128_cmac_message(btstack_crypto_aes128_cmac_t * request, const uint8_t * key, uint16_t len, const uint8_t * message,  uint8_t * hash, void (* callback)(void * arg), void * callback_arg);
177 
178 /**
179  * Calculate AES128-CMAC with key ZERO and complete message
180  * @param request
181  * @param len of message
182  * @param message
183  * @param hash
184  * @param callback
185  * @param callback_arg
186  */
187 void btstack_crypto_aes128_cmac_zero(btstack_crypto_aes128_cmac_t * request, uint16_t len, const uint8_t * message,  uint8_t * hash, void (* callback)(void * arg), void * callback_arg);
188 
189 /**
190  * Generate Elliptic Curve Public/Private Key Pair (FIPS P-256)
191  * @note BTstack uses a single ECC key pair per reset.
192  * @note If LE Controller is used for ECC, private key cannot be read or managed
193  * @param request
194  * @param public_key (64 bytes)
195  * @param callback
196  * @param callback_arg
197  */
198 void btstack_crypto_ecc_p256_generate_key(btstack_crypto_ecc_p256_t * request, uint8_t * public_key, void (* callback)(void * arg), void * callback_arg);
199 
200 /**
201  * Calculate Diffie-Hellman Key based on local private key and remote public key
202  * @param request
203  * @param public_key (64 bytes)
204  * @param dhkey (32 bytes)
205  * @param callback
206  * @param callback_arg
207  */
208 void btstack_crypto_ecc_p256_calculate_dhkey(btstack_crypto_ecc_p256_t * request, const uint8_t * public_key, uint8_t * dhkey, void (* callback)(void * arg), void * callback_arg);
209 
210 /*
211  * Validate public key (not implemented for LE Controller ECC)
212  * @param public_key (64 bytes)
213  * @result 0 == valid
214  */
215 int btstack_crypto_ecc_p256_validate_public_key(const uint8_t * public_key);
216 
217 /**
218  * Initialize Counter with CBC-MAC for Bluetooth Mesh (L=2)
219  * @param request
220  * @param nonce
221  * @param key
222  * @param message_len
223  * @param auth_len
224  */
225 void btstack_crypo_ccm_init(btstack_crypto_ccm_t * request, const uint8_t * key, const uint8_t * nonce, uint16_t message_len, uint8_t auth_len);
226 
227 /**
228  * Get authentication value after encrypt or decrypt operation
229  * @param request
230  * @param authentication_value
231  */
232 void btstack_crypo_ccm_get_authentication_value(btstack_crypto_ccm_t * request, uint8_t * authentication_value);
233 
234 /**
235  * Encrypt block - can be called multiple times. len must be a multiply of 16 for all but the last call
236  * @param request
237  * @param len (16 bytes for all but the last block)
238  * @param plaintext  (16 bytes)
239  * @param ciphertext (16 bytes)
240  * @param callback
241  * @param callback_arg
242  */
243 void btstack_crypto_ccm_encrypt_block(btstack_crypto_ccm_t * request, uint16_t len, const uint8_t * plaintext, uint8_t * ciphertext, void (* callback)(void * arg), void * callback_arg);
244 
245 /**
246  * Decrypt block - can be called multiple times. len must be a multiply of 16 for all but the last call
247  * @param request
248  * @param len (16 for all but last block)
249  * @param ciphertext (16 bytes)
250  * @param plaintext  (16 bytes)
251  * @param callback
252  * @param callback_arg
253  */
254 void btstack_crypto_ccm_decrypt_block(btstack_crypto_ccm_t * request, uint16_t len, const uint8_t * ciphertext, uint8_t * plaintext, void (* callback)(void * arg), void * callback_arg);
255 
256 #if defined __cplusplus
257 }
258 #endif
259 
260 #endif /* __BTSTACK_CTRYPTO_H */
261