/*      $OpenBSD: pkcs7test.c,v 1.5 2021/04/07 17:21:40 tb Exp $        */
/*
 * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <err.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/pkcs7.h>
#include <openssl/x509.h>

const char certificate[] = "\
-----BEGIN CERTIFICATE----- \n\
MIIDpTCCAo2gAwIBAgIJAPYm3GvOr5eTMA0GCSqGSIb3DQEBBQUAMHAxCzAJBgNV \n\
BAYTAlVLMRYwFAYDVQQKDA1PcGVuU1NMIEdyb3VwMSIwIAYDVQQLDBlGT1IgVEVT \n\
VElORyBQVVJQT1NFUyBPTkxZMSUwIwYDVQQDDBxPcGVuU1NMIFRlc3QgSW50ZXJt \n\
ZWRpYXRlIENBMB4XDTE0MDUyNDE0NDUxMVoXDTI0MDQwMTE0NDUxMVowZDELMAkG \n\
A1UEBhMCVUsxFjAUBgNVBAoMDU9wZW5TU0wgR3JvdXAxIjAgBgNVBAsMGUZPUiBU \n\
RVNUSU5HIFBVUlBPU0VTIE9OTFkxGTAXBgNVBAMMEFRlc3QgQ2xpZW50IENlcnQw \n\
ggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQC0ranbHRLcLVqN+0BzcZpY \n\
+yOLqxzDWT1LD9eW1stC4NzXX9/DCtSIVyN7YIHdGLrIPr64IDdXXaMRzgZ2rOKs \n\
lmHCAiFpO/ja99gGCJRxH0xwQatqAULfJVHeUhs7OEGOZc2nWifjqKvGfNTilP7D \n\
nwi69ipQFq9oS19FmhwVHk2wg7KZGHI1qDyG04UrfCZMRitvS9+UVhPpIPjuiBi2 \n\
x3/FZIpL5gXJvvFK6xHY63oq2asyzBATntBgnP4qJFWWcvRx24wF1PnZabxuVoL2 \n\
bPnQ/KvONDrw3IdqkKhYNTul7jEcu3OlcZIMw+7DiaKJLAzKb/bBF5gm/pwW6As9 \n\
AgMBAAGjTjBMMAwGA1UdEwEB/wQCMAAwDgYDVR0PAQH/BAQDAgXgMCwGCWCGSAGG \n\
+EIBDQQfFh1PcGVuU1NMIEdlbmVyYXRlZCBDZXJ0aWZpY2F0ZTANBgkqhkiG9w0B \n\
AQUFAAOCAQEAJzA4KTjkjXGSC4He63yX9Br0DneGBzjAwc1H6f72uqnCs8m7jgkE \n\
PQJFdTzQUKh97QPUuayZ2gl8XHagg+iWGy60Kw37gQ0+lumCN2sllvifhHU9R03H \n\
bWtS4kue+yQjMbrzf3zWygMDgwvFOUAIgBpH9qGc+CdNu97INTYd0Mvz51vLlxRn \n\
sC5aBYCWaZFnw3lWYxf9eVFRy9U+DkYFqX0LpmbDtcKP7AZGE6ZwSzaim+Cnoz1u \n\
Cgn+QmpFXgJKMFIZ82iSZISn+JkCCGxctZX1lMvai4Wi8Y0HxW9FTFZ6KBNwwE4B \n\
zjbN/ehBkgLlW/DWfi44DvwUHmuU6QP3cw== \n\
-----END CERTIFICATE----- \n\
";

const char private_key[] = "\
-----BEGIN RSA PRIVATE KEY----- \n\
MIIEpQIBAAKCAQEAtK2p2x0S3C1ajftAc3GaWPsji6scw1k9Sw/XltbLQuDc11/f \n\
wwrUiFcje2CB3Ri6yD6+uCA3V12jEc4GdqzirJZhwgIhaTv42vfYBgiUcR9McEGr \n\
agFC3yVR3lIbOzhBjmXNp1on46irxnzU4pT+w58IuvYqUBavaEtfRZocFR5NsIOy \n\
mRhyNag8htOFK3wmTEYrb0vflFYT6SD47ogYtsd/xWSKS+YFyb7xSusR2Ot6Ktmr \n\
MswQE57QYJz+KiRVlnL0cduMBdT52Wm8blaC9mz50PyrzjQ68NyHapCoWDU7pe4x \n\
HLtzpXGSDMPuw4miiSwMym/2wReYJv6cFugLPQIDAQABAoIBAAZOyc9MhIwLSU4L \n\
p4RgQvM4UVVe8/Id+3XTZ8NsXExJbWxXfIhiqGjaIfL8u4vsgRjcl+v1s/jo2/iT \n\
KMab4o4D8gXD7UavQVDjtjb/ta79WL3SjRl2Uc9YjjMkyq6WmDNQeo2NKDdafCTB \n\
1uzSJtLNipB8Z53ELPuHJhxX9QMHrMnuha49riQgXZ7buP9iQrHJFhImBjSzbxJx \n\
L+TI6rkyLSf9Wi0Pd3L27Ob3QWNfNRYNSeTE+08eSRChkur5W0RuXAcuAICdQlCl \n\
LBvWO/LmmvbzCqiDcgy/TliSb6CGGwgiNG7LJZmlkYNj8laGwalNlYZs3UrVv6NO \n\
Br2loAECgYEA2kvCvPGj0Dg/6g7WhXDvAkEbcaL1tSeCxBbNH+6HS2UWMWvyTtCn \n\
/bbD519QIdkvayy1QjEf32GV/UjUVmlULMLBcDy0DGjtL3+XpIhLKWDNxN1v1/ai \n\
1oz23ZJCOgnk6K4qtFtlRS1XtynjA+rBetvYvLP9SKeFrnpzCgaA2r0CgYEA0+KX \n\
1ACXDTNH5ySX3kMjSS9xdINf+OOw4CvPHFwbtc9aqk2HePlEsBTz5I/W3rKwXva3 \n\
NqZ/bRqVVeZB/hHKFywgdUQk2Uc5z/S7Lw70/w1HubNTXGU06Ngb6zOFAo/o/TwZ \n\
zTP1BMIKSOB6PAZPS3l+aLO4FRIRotfFhgRHOoECgYEAmiZbqt8cJaJDB/5YYDzC \n\
mp3tSk6gIb936Q6M5VqkMYp9pIKsxhk0N8aDCnTU+kIK6SzWBpr3/d9Ecmqmfyq7 \n\
5SvWO3KyVf0WWK9KH0abhOm2BKm2HBQvI0DB5u8sUx2/hsvOnjPYDISbZ11t0MtK \n\
u35Zy89yMYcSsIYJjG/ROCUCgYEAgI2P9G5PNxEP5OtMwOsW84Y3Xat/hPAQFlI+ \n\
HES+AzbFGWJkeT8zL2nm95tVkFP1sggZ7Kxjz3w7cpx7GX0NkbWSE9O+T51pNASV \n\
tN1sQ3p5M+/a+cnlqgfEGJVvc7iAcXQPa3LEi5h2yPR49QYXAgG6cifn3dDSpmwn \n\
SUI7PQECgYEApGCIIpSRPLAEHTGmP87RBL1smurhwmy2s/pghkvUkWehtxg0sGHh \n\
kuaqDWcskogv+QC0sVdytiLSz8G0DwcEcsHK1Fkyb8A+ayiw6jWJDo2m9+IF4Fww \n\
1Te6jFPYDESnbhq7+TLGgHGhtwcu5cnb4vSuYXGXKupZGzoLOBbv1Zw= \n\
-----END RSA PRIVATE KEY----- \n\
";

const char message[] = "\
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do \r\n\
eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut   \r\n\
enim ad minim veniam, quis nostrud exercitation ullamco laboris  \r\n\
nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor   \r\n\
in reprehenderit in voluptate velit esse cillum dolore eu fugiat \r\n\
nulla pariatur. Excepteur sint occaecat cupidatat non proident,  \r\n\
sunt in culpa qui officia deserunt mollit anim id est laborum.   \r\n\
";

static int
x509_store_callback(int ok, X509_STORE_CTX *ctx)
{
        /* Pretend the certificate issuer is valid... */
        return 1;
}

static void
fatal(const char *msg)
{
        warnx("%s", msg);
        ERR_print_errors_fp(stderr);
        exit(1);
}

static void
message_compare(const char *out, size_t len)
{
        if (len != sizeof(message)) {
                fprintf(stderr, "FAILURE: length mismatch (%zu != %zu)\n",
                    len, sizeof(message));
                exit(1);
        }
        if (memcmp(out, message, len) != 0) {
                fprintf(stderr, "FAILURE: message mismatch\n");
                fprintf(stderr, "Got:\n%s\n", out);
                fprintf(stderr, "Want:\n%s\n", message);
                exit(1);
        }
}

int
main(int argc, char **argv)
{
        BIO *bio_in, *bio_content, *bio_out, *bio_cert, *bio_pkey;
        STACK_OF(X509) *certs;
        const EVP_CIPHER *cipher;
        EVP_PKEY *pkey;
        X509_STORE *store;
        X509 *cert;
        PKCS7 *p7;
        size_t len;
        char *out;
        int flags;

        ERR_load_crypto_strings();
        OpenSSL_add_all_algorithms();

        /*
         * A bunch of setup...
         */
        cipher = EVP_aes_256_cbc();
        if (cipher == NULL)
                fatal("cipher");

        certs = sk_X509_new_null();
        if (certs == NULL)
                fatal("sk_X509_new_null");

        bio_cert = BIO_new_mem_buf((char *)certificate, sizeof(certificate));
        if (bio_cert == NULL)
                fatal("BIO_new_mem_buf certificate");

        cert = PEM_read_bio_X509_AUX(bio_cert, NULL, NULL, NULL);
        if (cert == NULL)
                fatal("PEM_read_bio_X509_AUX");
        sk_X509_push(certs, cert);

        store = X509_STORE_new();
        if (store == NULL)
                fatal("X509_STORE_new");
        X509_STORE_set_verify_cb(store, x509_store_callback);

        bio_pkey = BIO_new_mem_buf((char *)private_key, sizeof(private_key));
        if (bio_pkey == NULL)
                fatal("BIO_new_mem_buf private_key");

        pkey = PEM_read_bio_PrivateKey(bio_pkey, NULL, NULL, NULL);
        if (pkey == NULL)
                fatal("PEM_read_bio_PrivateKey");

        bio_content = BIO_new_mem_buf((char *)message, sizeof(message));
        if (bio_content == NULL)
                fatal("BIO_new_mem_buf message");

        /*
         * Encrypt and then decrypt.
         */
        if (BIO_reset(bio_content) != 1)
                fatal("BIO_reset");
        bio_out = BIO_new(BIO_s_mem());
        if (bio_out == NULL)
                fatal("BIO_new");

        p7 = PKCS7_encrypt(certs, bio_content, cipher, 0);
        if (p7 == NULL)
                fatal("PKCS7_encrypt");
        if (PEM_write_bio_PKCS7(bio_out, p7) != 1)
                fatal("PEM_write_bio_PKCS7");
        PKCS7_free(p7);

        bio_in = bio_out;
        bio_out = BIO_new(BIO_s_mem());
        if (bio_out == NULL)
                fatal("BIO_new");

        p7 = PEM_read_bio_PKCS7(bio_in, NULL, NULL, NULL);
        if (p7 == NULL)
                fatal("PEM_read_bio_PKCS7");
        if (PKCS7_decrypt(p7, pkey, cert, bio_out, 0) != 1)
                fatal("PKCS7_decrypt");
        PKCS7_free(p7);

        len = BIO_get_mem_data(bio_out, &out);
        message_compare(out, len);

        BIO_free(bio_in);
        BIO_free(bio_out);

        /*
         * Sign and then verify.
         */
        if (BIO_reset(bio_content) != 1)
                fatal("BIO_reset");
        bio_out = BIO_new(BIO_s_mem());
        if (bio_out == NULL)
                fatal("BIO_new");

        p7 = PKCS7_sign(cert, pkey, certs, bio_content, 0);
        if (p7 == NULL)
                fatal("PKCS7_sign");
        if (PEM_write_bio_PKCS7(bio_out, p7) != 1)
                fatal("PEM_write_bio_PKCS7");
        PKCS7_free(p7);

        bio_in = bio_out;
        bio_out = BIO_new(BIO_s_mem());
        if (bio_out == NULL)
                fatal("BIO_new");

        p7 = PEM_read_bio_PKCS7(bio_in, NULL, NULL, NULL);
        if (p7 == NULL)
                fatal("PEM_read_bio_PKCS7");
        if (PKCS7_verify(p7, certs, store, NULL, bio_out, 0) != 1)
                fatal("PKCS7_verify");
        PKCS7_free(p7);

        len = BIO_get_mem_data(bio_out, &out);
        message_compare(out, len);

        BIO_free(bio_in);
        BIO_free(bio_out);

        /*
         * Sign and then verify with a detached signature.
         */
        if (BIO_reset(bio_content) != 1)
                fatal("BIO_reset");
        bio_out = BIO_new(BIO_s_mem());
        if (bio_out == NULL)
                fatal("BIO_new");

        flags = PKCS7_DETACHED|PKCS7_PARTIAL;
        p7 = PKCS7_sign(NULL, NULL, NULL, bio_content, flags);
        if (p7 == NULL)
                fatal("PKCS7_sign");
        if (PKCS7_sign_add_signer(p7, cert, pkey, NULL, flags) == NULL)
                fatal("PKCS7_sign_add_signer");
        if (PKCS7_final(p7, bio_content, flags) != 1)
                fatal("PKCS7_final");
        if (PEM_write_bio_PKCS7(bio_out, p7) != 1)
                fatal("PEM_write_bio_PKCS7");
        PKCS7_free(p7);

        /* bio_out contains only the detached signature. */
        bio_in = bio_out;
        if (BIO_reset(bio_content) != 1)
                fatal("BIO_reset");

        bio_out = BIO_new(BIO_s_mem());
        if (bio_out == NULL)
                fatal("BIO_new");

        p7 = PEM_read_bio_PKCS7(bio_in, NULL, NULL, NULL);
        if (p7 == NULL)
                fatal("PEM_read_bio_PKCS7");
        if (PKCS7_verify(p7, certs, store, bio_content, bio_out, flags) != 1)
                fatal("PKCS7_verify");
        PKCS7_free(p7);

        len = BIO_get_mem_data(bio_out, &out);
        message_compare(out, len);

        BIO_free(bio_in);
        BIO_free(bio_out);
        BIO_free(bio_content);
        BIO_free(bio_cert);
        BIO_free(bio_pkey);

        EVP_PKEY_free(pkey);

        X509_free(cert);
        X509_STORE_free(store);
        sk_X509_free(certs);

        return 0;
}