1 /**
2  * \file config-ccm-psk-dtls1_2.h
3  *
4  * \brief Small configuration for DTLS 1.2 with PSK and AES-CCM ciphersuites
5  */
6 /*
7  *  Copyright The Mbed TLS Contributors
8  *  SPDX-License-Identifier: Apache-2.0
9  *
10  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
11  *  not use this file except in compliance with the License.
12  *  You may obtain a copy of the License at
13  *
14  *  http://www.apache.org/licenses/LICENSE-2.0
15  *
16  *  Unless required by applicable law or agreed to in writing, software
17  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
18  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19  *  See the License for the specific language governing permissions and
20  *  limitations under the License.
21  */
22 /*
23  * Minimal configuration for DTLS 1.2 with PSK and AES-CCM ciphersuites
24  *
25  * Distinguishing features:
26  * - Optimized for small code size, low bandwidth (on an unreliable transport),
27  *   and low RAM usage.
28  * - No asymmetric cryptography (no certificates, no Diffie-Hellman key
29  *   exchange).
30  * - Fully modern and secure (provided the pre-shared keys are generated and
31  *   stored securely).
32  * - Very low record overhead with CCM-8.
33  * - Includes several optional DTLS features typically used in IoT.
34  *
35  * See README.txt for usage instructions.
36  */
37 
38 /* System support */
39 //#define MBEDTLS_HAVE_TIME /* Optionally used in Hello messages */
40 /* Other MBEDTLS_HAVE_XXX flags irrelevant for this configuration */
41 
42 /* Mbed TLS modules */
43 #define MBEDTLS_AES_C
44 #define MBEDTLS_CCM_C
45 #define MBEDTLS_CIPHER_C
46 #define MBEDTLS_CTR_DRBG_C
47 #define MBEDTLS_ENTROPY_C
48 #define MBEDTLS_MD_C
49 #define MBEDTLS_NET_C
50 /* The library does not currently support enabling SHA-224 without SHA-256.
51  * A future version of the library will have this option disabled
52  * by default. */
53 #define MBEDTLS_SHA224_C
54 #define MBEDTLS_SHA256_C
55 #define MBEDTLS_SSL_CLI_C
56 #define MBEDTLS_SSL_COOKIE_C
57 #define MBEDTLS_SSL_SRV_C
58 #define MBEDTLS_SSL_TLS_C
59 #define MBEDTLS_TIMING_C
60 
61 /* TLS protocol feature support */
62 #define MBEDTLS_KEY_EXCHANGE_PSK_ENABLED
63 #define MBEDTLS_SSL_PROTO_TLS1_2
64 #define MBEDTLS_SSL_PROTO_DTLS
65 #define MBEDTLS_SSL_DTLS_ANTI_REPLAY
66 #define MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE
67 #define MBEDTLS_SSL_DTLS_CONNECTION_ID
68 #define MBEDTLS_SSL_DTLS_HELLO_VERIFY
69 #define MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
70 
71 /*
72  * Use only CCM_8 ciphersuites, and
73  * save ROM and a few bytes of RAM by specifying our own ciphersuite list
74  */
75 #define MBEDTLS_SSL_CIPHERSUITES                        \
76         MBEDTLS_TLS_PSK_WITH_AES_256_CCM_8,             \
77         MBEDTLS_TLS_PSK_WITH_AES_128_CCM_8
78 
79 /*
80  * Save RAM at the expense of interoperability: do this only if you control
81  * both ends of the connection!  (See comments in "mbedtls/ssl.h".)
82  * The optimal size here depends on the typical size of records.
83  */
84 #define MBEDTLS_SSL_IN_CONTENT_LEN              256
85 #define MBEDTLS_SSL_OUT_CONTENT_LEN             256
86 
87 /* Save RAM at the expense of ROM */
88 #define MBEDTLS_AES_ROM_TABLES
89 
90 /* Save some RAM by adjusting to your exact needs */
91 #define MBEDTLS_PSK_MAX_LEN    16 /* 128-bits keys are generally enough */
92 
93 /*
94  * You should adjust this to the exact number of sources you're using: default
95  * is the "platform_entropy_poll" source, but you may want to add other ones
96  * Minimum is 2 for the entropy test suite.
97  */
98 #define MBEDTLS_ENTROPY_MAX_SOURCES 2
99 
100 /* These defines are present so that the config modifying scripts can enable
101  * them during tests/scripts/test-ref-configs.pl */
102 //#define MBEDTLS_USE_PSA_CRYPTO
103 //#define MBEDTLS_PSA_CRYPTO_C
104 
105 /* Error messages and TLS debugging traces
106  * (huge code size increase, needed for tests/ssl-opt.sh) */
107 //#define MBEDTLS_DEBUG_C
108 //#define MBEDTLS_ERROR_C
109