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58bd45d8 | 1 | /* |
fecb3aae | 2 | * Copyright 2021-2022 The OpenSSL Project Authors. All Rights Reserved. |
58bd45d8 P |
3 | * |
4 | * Licensed under the Apache License 2.0 (the "License"). You may not use | |
5 | * this file except in compliance with the License. You can obtain a copy | |
6 | * in the file LICENSE in the source distribution or at | |
7 | * https://www.openssl.org/source/license.html | |
8 | */ | |
9 | ||
10 | #include <stdio.h> | |
11 | #include <stdlib.h> | |
12 | #include <openssl/core_names.h> | |
13 | #include <openssl/evp.h> | |
14 | #include <openssl/params.h> | |
15 | #include <openssl/err.h> | |
16 | ||
17 | /* | |
18 | * Taken from NIST's GCM Test Vectors | |
19 | * http://csrc.nist.gov/groups/STM/cavp/ | |
20 | */ | |
21 | ||
22 | /* | |
23 | * Hard coding the key into an application is very bad. | |
24 | * It is done here solely for educational purposes. | |
25 | */ | |
26 | static unsigned char key[] = { | |
27 | 0x77, 0xbe, 0x63, 0x70, 0x89, 0x71, 0xc4, 0xe2, | |
28 | 0x40, 0xd1, 0xcb, 0x79, 0xe8, 0xd7, 0x7f, 0xeb | |
29 | }; | |
30 | ||
31 | /* | |
32 | * The initialisation vector (IV) is better not being hard coded too. | |
33 | * Repeating password/IV pairs compromises the integrity of GMAC. | |
34 | * The IV is not considered secret information and is safe to store with | |
35 | * an encrypted password. | |
36 | */ | |
37 | static unsigned char iv[] = { | |
38 | 0xe0, 0xe0, 0x0f, 0x19, 0xfe, 0xd7, 0xba, | |
39 | 0x01, 0x36, 0xa7, 0x97, 0xf3 | |
40 | }; | |
41 | ||
42 | static unsigned char data[] = { | |
43 | 0x7a, 0x43, 0xec, 0x1d, 0x9c, 0x0a, 0x5a, 0x78, | |
44 | 0xa0, 0xb1, 0x65, 0x33, 0xa6, 0x21, 0x3c, 0xab | |
45 | }; | |
46 | ||
47 | static const unsigned char expected_output[] = { | |
48 | 0x20, 0x9f, 0xcc, 0x8d, 0x36, 0x75, 0xed, 0x93, | |
49 | 0x8e, 0x9c, 0x71, 0x66, 0x70, 0x9d, 0xd9, 0x46 | |
50 | }; | |
51 | ||
52 | /* | |
53 | * A property query used for selecting the GMAC implementation and the | |
54 | * underlying GCM mode cipher. | |
55 | */ | |
56 | static char *propq = NULL; | |
57 | ||
58 | int main(int argc, char **argv) | |
59 | { | |
60 | int rv = EXIT_FAILURE; | |
61 | EVP_MAC *mac = NULL; | |
62 | EVP_MAC_CTX *mctx = NULL; | |
63 | unsigned char out[16]; | |
64 | OSSL_PARAM params[4], *p = params; | |
65 | OSSL_LIB_CTX *library_context = NULL; | |
66 | size_t out_len = 0; | |
67 | ||
68 | library_context = OSSL_LIB_CTX_new(); | |
69 | if (library_context == NULL) { | |
70 | fprintf(stderr, "OSSL_LIB_CTX_new() returned NULL\n"); | |
71 | goto end; | |
72 | } | |
73 | ||
74 | /* Fetch the GMAC implementation */ | |
75 | mac = EVP_MAC_fetch(library_context, "GMAC", propq); | |
76 | if (mac == NULL) { | |
77 | fprintf(stderr, "EVP_MAC_fetch() returned NULL\n"); | |
78 | goto end; | |
79 | } | |
80 | ||
81 | /* Create a context for the GMAC operation */ | |
82 | mctx = EVP_MAC_CTX_new(mac); | |
83 | if (mctx == NULL) { | |
84 | fprintf(stderr, "EVP_MAC_CTX_new() returned NULL\n"); | |
85 | goto end; | |
86 | } | |
87 | ||
e304aa87 | 88 | /* GMAC requires a GCM mode cipher to be specified */ |
58bd45d8 P |
89 | *p++ = OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_CIPHER, |
90 | "AES-128-GCM", 0); | |
91 | ||
92 | /* | |
93 | * If a non-default property query is required when fetching the GCM mode | |
94 | * cipher, it needs to be specified too. | |
95 | */ | |
96 | if (propq != NULL) | |
97 | *p++ = OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_PROPERTIES, | |
98 | propq, 0); | |
99 | ||
100 | /* Set the initialisation vector (IV) */ | |
101 | *p++ = OSSL_PARAM_construct_octet_string(OSSL_CIPHER_PARAM_IV, | |
102 | iv, sizeof(iv)); | |
103 | *p = OSSL_PARAM_construct_end(); | |
104 | ||
105 | /* Initialise the GMAC operation */ | |
106 | if (!EVP_MAC_init(mctx, key, sizeof(key), params)) { | |
107 | fprintf(stderr, "EVP_MAC_init() failed\n"); | |
108 | goto end; | |
109 | } | |
110 | ||
111 | /* Make one or more calls to process the data to be authenticated */ | |
112 | if (!EVP_MAC_update(mctx, data, sizeof(data))) { | |
113 | fprintf(stderr, "EVP_MAC_update() failed\n"); | |
114 | goto end; | |
115 | } | |
116 | ||
117 | /* Make one call to the final to get the MAC */ | |
118 | if (!EVP_MAC_final(mctx, out, &out_len, sizeof(out))) { | |
119 | fprintf(stderr, "EVP_MAC_final() failed\n"); | |
120 | goto end; | |
121 | } | |
122 | ||
123 | printf("Generated MAC:\n"); | |
124 | BIO_dump_indent_fp(stdout, out, out_len, 2); | |
125 | putchar('\n'); | |
126 | ||
127 | if (out_len != sizeof(expected_output)) { | |
128 | fprintf(stderr, "Generated MAC has an unexpected length\n"); | |
129 | goto end; | |
130 | } | |
131 | ||
132 | if (CRYPTO_memcmp(expected_output, out, sizeof(expected_output)) != 0) { | |
133 | fprintf(stderr, "Generated MAC does not match expected value\n"); | |
134 | goto end; | |
135 | } | |
136 | ||
137 | rv = EXIT_SUCCESS; | |
138 | end: | |
139 | EVP_MAC_CTX_free(mctx); | |
140 | EVP_MAC_free(mac); | |
141 | OSSL_LIB_CTX_free(library_context); | |
142 | if (rv != EXIT_SUCCESS) | |
143 | ERR_print_errors_fp(stderr); | |
144 | return rv; | |
145 | } |