1 /*
2 * Copyright 2008-2023 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 /* Simple S/MIME verification example */
11 #include <openssl/pem.h>
12 #include <openssl/cms.h>
13 #include <openssl/err.h>
14
15 /*
16 * print any signingTime attributes.
17 * signingTime is when each party purportedly signed the message.
18 */
print_signingTime(CMS_ContentInfo * cms)19 static void print_signingTime(CMS_ContentInfo *cms)
20 {
21 STACK_OF(CMS_SignerInfo) *sis;
22 CMS_SignerInfo *si;
23 X509_ATTRIBUTE *attr;
24 ASN1_TYPE *t;
25 ASN1_UTCTIME *utctime;
26 ASN1_GENERALIZEDTIME *gtime;
27 BIO *b;
28 int i, loc;
29
30 b = BIO_new_fp(stdout, BIO_NOCLOSE | BIO_FP_TEXT);
31 sis = CMS_get0_SignerInfos(cms);
32 for (i = 0; i < sk_CMS_SignerInfo_num(sis); i++) {
33 si = sk_CMS_SignerInfo_value(sis, i);
34 loc = CMS_signed_get_attr_by_NID(si, NID_pkcs9_signingTime, -1);
35 attr = CMS_signed_get_attr(si, loc);
36 t = X509_ATTRIBUTE_get0_type(attr, 0);
37 if (t == NULL)
38 continue;
39 switch (t->type) {
40 case V_ASN1_UTCTIME:
41 utctime = t->value.utctime;
42 ASN1_UTCTIME_print(b, utctime);
43 break;
44 case V_ASN1_GENERALIZEDTIME:
45 gtime = t->value.generalizedtime;
46 ASN1_GENERALIZEDTIME_print(b, gtime);
47 break;
48 default:
49 fprintf(stderr, "unrecognized signingTime type\n");
50 break;
51 }
52 BIO_printf(b, ": signingTime from SignerInfo %i\n", i);
53 }
54 BIO_free(b);
55 return;
56 }
57
main(int argc,char ** argv)58 int main(int argc, char **argv)
59 {
60 BIO *in = NULL, *out = NULL, *tbio = NULL, *cont = NULL;
61 X509_STORE *st = NULL;
62 X509 *cacert = NULL;
63 CMS_ContentInfo *cms = NULL;
64 int ret = EXIT_FAILURE;
65
66 OpenSSL_add_all_algorithms();
67 ERR_load_crypto_strings();
68
69 /* Set up trusted CA certificate store */
70
71 st = X509_STORE_new();
72 if (st == NULL)
73 goto err;
74
75 /* Read in CA certificate */
76 tbio = BIO_new_file("cacert.pem", "r");
77
78 if (tbio == NULL)
79 goto err;
80
81 cacert = PEM_read_bio_X509(tbio, NULL, 0, NULL);
82
83 if (cacert == NULL)
84 goto err;
85
86 if (!X509_STORE_add_cert(st, cacert))
87 goto err;
88
89 /* Open message being verified */
90
91 in = BIO_new_file("smout.txt", "r");
92
93 if (in == NULL)
94 goto err;
95
96 /* parse message */
97 cms = SMIME_read_CMS(in, &cont);
98
99 if (cms == NULL)
100 goto err;
101
102 print_signingTime(cms);
103
104 /* File to output verified content to */
105 out = BIO_new_file("smver.txt", "w");
106 if (out == NULL)
107 goto err;
108
109 if (!CMS_verify(cms, NULL, st, cont, out, 0)) {
110 fprintf(stderr, "Verification Failure\n");
111 goto err;
112 }
113
114 printf("Verification Successful\n");
115
116 ret = EXIT_SUCCESS;
117
118 err:
119 if (ret != EXIT_SUCCESS) {
120 fprintf(stderr, "Error Verifying Data\n");
121 ERR_print_errors_fp(stderr);
122 }
123
124 X509_STORE_free(st);
125 CMS_ContentInfo_free(cms);
126 X509_free(cacert);
127 BIO_free(in);
128 BIO_free(out);
129 BIO_free(tbio);
130 return ret;
131 }
132
