/* S/MIME signing example: 2 signers. OpenSSL 0.9.9 only */ #include <openssl/pem.h> #include <openssl/pkcs7.h> #include <openssl/err.h> int main(int argc, char **argv) { BIO *in = NULL, *out = NULL, *tbio = NULL; X509 *scert = NULL, *scert2 = NULL; EVP_PKEY *skey = NULL, *skey2 = NULL; PKCS7 *p7 = NULL; int ret = 1; OpenSSL_add_all_algorithms(); ERR_load_crypto_strings(); tbio = BIO_new_file("signer.pem", "r"); if (!tbio) goto err; scert = PEM_read_bio_X509(tbio, NULL, 0, NULL); BIO_reset(tbio); skey = PEM_read_bio_PrivateKey(tbio, NULL, 0, NULL); BIO_free(tbio); tbio = BIO_new_file("signer2.pem", "r"); if (!tbio) goto err; scert2 = PEM_read_bio_X509(tbio, NULL, 0, NULL); BIO_reset(tbio); skey2 = PEM_read_bio_PrivateKey(tbio, NULL, 0, NULL); if (!scert2 || !skey2) goto err; in = BIO_new_file("sign.txt", "r"); if (!in) goto err; p7 = PKCS7_sign(NULL, NULL, NULL, in, PKCS7_STREAM|PKCS7_PARTIAL); if (!p7) goto err; /* Add each signer in turn */ if (!PKCS7_sign_add_signer(p7, scert, skey, NULL, 0)) goto err; if (!PKCS7_sign_add_signer(p7, scert2, skey2, NULL, 0)) goto err; out = BIO_new_file("smout.txt", "w"); if (!out) goto err; /* NB: content included and finalized by SMIME_write_PKCS7 */ if (!SMIME_write_PKCS7(out, p7, in, PKCS7_STREAM)) goto err; ret = 0; err: if (ret) { fprintf(stderr, "Error Signing Data\n"); ERR_print_errors_fp(stderr); } if (p7) PKCS7_free(p7); if (scert) X509_free(scert); if (skey) EVP_PKEY_free(skey); if (scert2) X509_free(scert2); if (skey) EVP_PKEY_free(skey2); if (in) BIO_free(in); if (out) BIO_free(out); if (tbio) BIO_free(tbio); return ret; }