1 /*- 2 * Copyright 2022 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 const int gindex = 42; 51 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 */ 58 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 } 102 103 int main(int argc, char **argv) 104 { 105 int rv = 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 rv = 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 rv; 202 } 203