/* Simple S/MIME encrypt example */ #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 *rcert = NULL; STACK_OF(X509) *recips = NULL; PKCS7 *p7 = NULL; int ret = 1; /* * On OpenSSL 0.9.9 only: * for streaming set PKCS7_STREAM */ int flags = PKCS7_STREAM; OpenSSL_add_all_algorithms(); ERR_load_crypto_strings(); /* Read in recipient certificate */ tbio = BIO_new_file("signer.pem", "r"); if (!tbio) goto err; rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL); if (!rcert) goto err; /* Create recipient STACK and add recipient cert to it */ recips = sk_X509_new_null(); if (!recips || !sk_X509_push(recips, rcert)) goto err; /* sk_X509_pop_free will free up recipient STACK and its contents * so set rcert to NULL so it isn't freed up twice. */ rcert = NULL; /* Open content being encrypted */ in = BIO_new_file("encr.txt", "r"); if (!in) goto err; /* encrypt content */ p7 = PKCS7_encrypt(recips, in, EVP_des_ede3_cbc(), flags); if (!p7) goto err; out = BIO_new_file("smencr.txt", "w"); if (!out) goto err; /* Write out S/MIME message */ if (!SMIME_write_PKCS7(out, p7, in, flags)) goto err; ret = 0; err: if (ret) { fprintf(stderr, "Error Encrypting Data\n"); ERR_print_errors_fp(stderr); } if (p7) PKCS7_free(p7); if (rcert) X509_free(rcert); if (recips) sk_X509_pop_free(recips, X509_free); if (in) BIO_free(in); if (out) BIO_free(out); if (tbio) BIO_free(tbio); return ret; }