1 /*-
2 * Copyright 2022-2024 The OpenSSL Project Authors. All Rights Reserved.
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 /*
11 * Example showing how to validate DSA parameters.
12 *
13 * Proper FIPS 186-4 DSA (FFC) parameter validation requires that all
14 * the parameters used during parameter generation are supplied
15 * when doing the validation. Unfortunately saving DSA parameters as
16 * a PEM or DER file does not write out all required fields. Because
17 * of this the default provider normally only does a partial
18 * validation. The FIPS provider will however try to do a full
19 * validation. To force the default provider to use full
20 * validation the 'seed' that is output during generation must be
21 * added to the key. See doc/man7/EVP_PKEY-FFC for more information.
22 */
23
24 #include <openssl/evp.h>
25 #include <openssl/core_names.h>
26 #include <openssl/pem.h>
27 #include "dsa.inc"
28
29 /* The following values were output from the EVP_PKEY_DSA_paramgen demo */
30 static const char dsapem[] =
31 "-----BEGIN DSA PARAMETERS-----\n"
32 "MIICLAKCAQEA1pobSR1FJ3+Tvi0J6Tk1PSV2owZey1Nuo847hGw/59VCS6RPQEqr\n"
33 "vp5fhbvBjupBeVGA/AMH6rI4i4h6jlhurrqH1CqUHVcDhJzxV668bMLiP3mIxg5o\n"
34 "9Yq8x6BnSOtH5Je0tpeE0/fEvvLjCwBUbwnwWxzjANcvDUEt9XYeRrtB2v52fr56\n"
35 "hVYz3wMMNog4CEDOLTvx7/84eVPuUeWDRQFH1EaHMdulP34KBcatEEpEZapkepng\n"
36 "nohm9sFSPQhq2utpkH7pNXdG0EILBtRDCvUpF5720a48LYofdggh2VEZfgElAGFk\n"
37 "dW/CkvyBDmGIzil5aTz4MMsdudaVYgzt6wIhAPsSGC42Qa+X0AFGvonb5nmfUVm/\n"
38 "8aC+tHk7Nb2AYLHXAoIBADx5C0H1+QHsmGKvuOaY+WKUt7aWUrEivD1zBMJAQ6bL\n"
39 "Wv9lbCq1CFHvVzojeOVpn872NqDEpkx4HTpvqhxWL5CkbN/HaGItsQzkD59AQg3v\n"
40 "4YsLlkesq9Jq6x/aWetJXWO36fszFv1gpD3NY3wliBvMYHx62jfc5suh9D3ZZvu7\n"
41 "PLGH4X4kcfzK/R2b0oVbEBjVTe5GMRYZRqnvfSW2f2fA7BzI1OL83UxDDe58cL2M\n"
42 "GcAoUYXOBAfZ37qLMm2juf+o5gCrT4CXfRPu6kbapt7V/YIc1nsNgeAOKKoFBHBQ\n"
43 "gc5u5G6G/j79FVoSDq9DYwTJcHPsU+eHj1uWHso1AjQ=\n"
44 "-----END DSA PARAMETERS-----\n";
45
46 static const char hexseed[] =
47 "cba30ccd905aa7675a0b81769704bf3c"
48 "ccf2ca1892b2eaf6b9e2b38d9bf6affc"
49 "42ada55986d8a1772b442770954d0b65";
50 static const int gindex = 42;
51 static const int pcounter = 363;
52 static const char digest[] = "SHA384";
53
54 /*
55 * Create a new dsa param key that is the combination of an existing param key
56 * plus extra parameters.
57 */
create_merged_key(EVP_PKEY * dsaparams,const OSSL_PARAM * newparams,OSSL_LIB_CTX * libctx,const char * propq)58 static EVP_PKEY_CTX *create_merged_key(EVP_PKEY *dsaparams, const OSSL_PARAM *newparams,
59 OSSL_LIB_CTX *libctx, const char *propq)
60 {
61 EVP_PKEY_CTX *out = NULL;
62 EVP_PKEY_CTX *ctx = NULL;
63 EVP_PKEY *pkey = NULL;
64 OSSL_PARAM *mergedparams = NULL;
65 OSSL_PARAM *loadedparams = NULL;
66
67 /* Specify EVP_PKEY_KEY_PUBLIC here if you have a public key */
68 if (EVP_PKEY_todata(dsaparams, EVP_PKEY_KEY_PARAMETERS, &loadedparams) <= 0) {
69 fprintf(stderr, "EVP_PKEY_todata() failed\n");
70 goto cleanup;
71 }
72 mergedparams = OSSL_PARAM_merge(loadedparams, newparams);
73 if (mergedparams == NULL) {
74 fprintf(stderr, "OSSL_PARAM_merge() failed\n");
75 goto cleanup;
76 }
77
78 ctx = EVP_PKEY_CTX_new_from_name(libctx, "DSA", propq);
79 if (ctx == NULL) {
80 fprintf(stderr, "EVP_PKEY_CTX_new_from_name() failed\n");
81 goto cleanup;
82 }
83 if (EVP_PKEY_fromdata_init(ctx) <= 0
84 || EVP_PKEY_fromdata(ctx, &pkey,
85 EVP_PKEY_KEY_PARAMETERS, mergedparams) <= 0) {
86 fprintf(stderr, "EVP_PKEY_fromdata() failed\n");
87 goto cleanup;
88 }
89 out = EVP_PKEY_CTX_new_from_pkey(libctx, pkey, propq);
90 if (out == NULL) {
91 fprintf(stderr, "EVP_PKEY_CTX_new_from_pkey() failed\n");
92 goto cleanup;
93 }
94
95 cleanup:
96 EVP_PKEY_free(pkey);
97 OSSL_PARAM_free(loadedparams);
98 OSSL_PARAM_free(mergedparams);
99 EVP_PKEY_CTX_free(ctx);
100 return out;
101 }
102
main(int argc,char ** argv)103 int main(int argc, char **argv)
104 {
105 int ret = EXIT_FAILURE;
106 OSSL_LIB_CTX *libctx = NULL;
107 const char *propq = NULL;
108 EVP_PKEY *dsaparamskey = NULL;
109 EVP_PKEY_CTX *ctx = NULL;
110 EVP_PKEY_CTX *ctx1 = NULL;
111 EVP_PKEY_CTX *ctx2 = NULL;
112 BIO *in = NULL;
113 OSSL_PARAM params[6];
114 unsigned char seed[64];
115 size_t seedlen;
116
117 if (!OPENSSL_hexstr2buf_ex(seed, sizeof(seed), &seedlen, hexseed, '\0'))
118 goto cleanup;
119 /*
120 * This example loads the PEM data from a memory buffer
121 * Use BIO_new_fp() to load a PEM file instead
122 */
123 in = BIO_new_mem_buf(dsapem, strlen(dsapem));
124 if (in == NULL) {
125 fprintf(stderr, "BIO_new_mem_buf() failed\n");
126 goto cleanup;
127 }
128
129 /* Load DSA params from pem data */
130 dsaparamskey = PEM_read_bio_Parameters_ex(in, NULL, libctx, propq);
131 if (dsaparamskey == NULL) {
132 fprintf(stderr, "Failed to load dsa params\n");
133 goto cleanup;
134 }
135
136 ctx = EVP_PKEY_CTX_new_from_pkey(libctx, dsaparamskey, propq);
137 if (ctx == NULL) {
138 fprintf(stderr, "EVP_PKEY_CTX_new_from_pkey() failed\n");
139 goto cleanup;
140 }
141 /*
142 * When using the default provider this only does a partial check to
143 * make sure that the values of p, q and g are ok.
144 * This will fail however if the FIPS provider is used since it does
145 * a proper FIPS 186-4 key validation which requires extra parameters
146 */
147 if (EVP_PKEY_param_check(ctx) <= 0) {
148 fprintf(stderr, "Simple EVP_PKEY_param_check() failed\n");
149 goto cleanup;
150 }
151
152 /*
153 * Setup parameters that we want to add.
154 * For illustration purposes it deliberately omits a required parameter.
155 */
156 params[0] = OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_FFC_TYPE,
157 "fips186_4", 0);
158 /* Force it to do a proper validation by setting the seed */
159 params[1] = OSSL_PARAM_construct_octet_string(OSSL_PKEY_PARAM_FFC_SEED,
160 (void *)seed, seedlen);
161 params[2] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_FFC_GINDEX, (int *)&gindex);
162 params[3] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_FFC_PCOUNTER, (int *)&pcounter);
163 params[4] = OSSL_PARAM_construct_end();
164
165 /* generate a new key that is the combination of the existing key and the new params */
166 ctx1 = create_merged_key(dsaparamskey, params, libctx, propq);
167 if (ctx1 == NULL)
168 goto cleanup;
169 /* This will fail since not all the parameters used for key generation are added */
170 if (EVP_PKEY_param_check(ctx1) > 0) {
171 fprintf(stderr, "EVP_PKEY_param_check() should fail\n");
172 goto cleanup;
173 }
174
175 /*
176 * Add the missing parameters onto the end of the existing list of params
177 * If the default was used for the generation then this parameter is not
178 * needed
179 */
180 params[4] = OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_FFC_DIGEST,
181 (char *)digest, 0);
182 params[5] = OSSL_PARAM_construct_end();
183 ctx2 = create_merged_key(dsaparamskey, params, libctx, propq);
184 if (ctx2 == NULL)
185 goto cleanup;
186 if (EVP_PKEY_param_check(ctx2) <= 0) {
187 fprintf(stderr, "EVP_PKEY_param_check() failed\n");
188 goto cleanup;
189 }
190
191 if (!dsa_print_key(EVP_PKEY_CTX_get0_pkey(ctx2), 0, libctx, propq))
192 goto cleanup;
193
194 ret = EXIT_SUCCESS;
195 cleanup:
196 EVP_PKEY_free(dsaparamskey);
197 EVP_PKEY_CTX_free(ctx2);
198 EVP_PKEY_CTX_free(ctx1);
199 EVP_PKEY_CTX_free(ctx);
200 BIO_free(in);
201 return ret;
202 }
203
