/* This callback is called for every certificate in a chain. ok is true if
OpenSSL's internal verification has verified the certificate. We don't change
anything about the verification, we only need access to the certificates to
provide diagnostics. */
static int verify_callback(int ok, X509_STORE_CTX *store)
{
X509 *cert = X509_STORE_CTX_get_current_cert(store);
int err = X509_STORE_CTX_get_error(store);
/* Print the subject, issuer, and fingerprint depending on the verbosity
level. */
if ((!ok && o.verbose) || o.debug > 1) {
char digest_buf[SHA1_STRING_LENGTH + 1];
loguser("Subject: ");
X509_NAME_print_ex_fp(stderr, X509_get_subject_name(cert), 0, XN_FLAG_COMPAT);
loguser_noprefix("\n");
loguser("Issuer: ");
X509_NAME_print_ex_fp(stderr, X509_get_issuer_name(cert), 0, XN_FLAG_COMPAT);
loguser_noprefix("\n");
assert(ssl_cert_fp_str_sha1(cert, digest_buf, sizeof(digest_buf)) != NULL);
loguser("SHA-1 fingerprint: %s\n", digest_buf);
}
if (!ok && o.verbose) {
loguser("Certificate verification failed (%s).\n",
X509_verify_cert_error_string(err));
}
return ok;
}
/* Depending on verbosity, print a message that a connection was established. */
static void connect_report(nsock_iod nsi)
{
union sockaddr_u peer;
zmem(&peer, sizeof(peer.storage));
nsi_getlastcommunicationinfo(nsi, NULL, NULL, NULL,
&peer.sockaddr, sizeof(peer.storage));
if (o.verbose) {
#ifdef HAVE_OPENSSL
if (nsi_checkssl(nsi)) {
X509 *cert;
X509_NAME *subject;
char digest_buf[SHA1_STRING_LENGTH + 1];
char *fp;
loguser("SSL connection to %s:%hu.", inet_socktop(&peer), nsi_peerport(nsi));
cert = SSL_get_peer_certificate((SSL *) nsi_getssl(nsi));
ncat_assert(cert != NULL);
subject = X509_get_subject_name(cert);
if (subject != NULL) {
char buf[256];
int n;
n = X509_NAME_get_text_by_NID(subject, NID_organizationName, buf, sizeof(buf));
if (n >= 0 && n <= sizeof(buf) - 1)
loguser_noprefix(" %s", buf);
}
loguser_noprefix("\n");
fp = ssl_cert_fp_str_sha1(cert, digest_buf, sizeof(digest_buf));
ncat_assert(fp == digest_buf);
loguser("SHA-1 fingerprint: %s\n", digest_buf);
} else {
#if HAVE_SYS_UN_H
if (peer.sockaddr.sa_family == AF_UNIX)
loguser("Connected to %s.\n", peer.un.sun_path);
else
#endif
loguser("Connected to %s:%hu.\n", inet_socktop(&peer), nsi_peerport(nsi));
}
#else
#if HAVE_SYS_UN_H
if (peer.sockaddr.sa_family == AF_UNIX)
loguser("Connected to %s.\n", peer.un.sun_path);
else
#endif
loguser("Connected to %s:%hu.\n", inet_socktop(&peer), nsi_peerport(nsi));
#endif
}
}
SSL_CTX *setup_ssl_listen(void)
{
const SSL_METHOD *method;
if (sslctx)
goto done;
SSL_library_init();
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
SSL_load_error_strings();
/* RAND_status initializes the random number generator through a variety of
platform-dependent methods, then returns 1 if there is enough entropy or
0 otherwise. This seems to be a good platform-independent way of seeding
the generator, as well as of refusing to continue without enough
entropy. */
if (!RAND_status())
bye("Failed to seed OpenSSL PRNG (RAND_status returned false).");
if (!(method = SSLv23_server_method()))
bye("SSLv23_server_method(): %s.", ERR_error_string(ERR_get_error(), NULL));
if (!(sslctx = SSL_CTX_new(method)))
bye("SSL_CTX_new(): %s.", ERR_error_string(ERR_get_error(), NULL));
SSL_CTX_set_options(sslctx, SSL_OP_ALL | SSL_OP_NO_SSLv2);
/* Secure ciphers list taken from Nsock. */
if (!SSL_CTX_set_cipher_list(sslctx, "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH"))
bye("Unable to set OpenSSL cipher list: %s", ERR_error_string(ERR_get_error(), NULL));
if (o.sslcert == NULL && o.sslkey == NULL) {
X509 *cert;
EVP_PKEY *key;
char digest_buf[SHA1_STRING_LENGTH + 1];
if (o.verbose)
loguser("Generating a temporary %d-bit RSA key. Use --ssl-key and --ssl-cert to use a permanent one.\n", DEFAULT_KEY_BITS);
if (ssl_gen_cert(&cert, &key) == 0)
bye("ssl_gen_cert(): %s.", ERR_error_string(ERR_get_error(), NULL));
if (o.verbose) {
char *fp;
fp = ssl_cert_fp_str_sha1(cert, digest_buf, sizeof(digest_buf));
ncat_assert(fp == digest_buf);
loguser("SHA-1 fingerprint: %s\n", digest_buf);
}
if (SSL_CTX_use_certificate(sslctx, cert) != 1)
bye("SSL_CTX_use_certificate(): %s.", ERR_error_string(ERR_get_error(), NULL));
if (SSL_CTX_use_PrivateKey(sslctx, key) != 1)
bye("SSL_CTX_use_PrivateKey(): %s.", ERR_error_string(ERR_get_error(), NULL));
X509_free(cert);
EVP_PKEY_free(key);
} else {
if (o.sslcert == NULL || o.sslkey == NULL)
bye("The --ssl-key and --ssl-cert options must be used together.");
if (SSL_CTX_use_certificate_chain_file(sslctx, o.sslcert) != 1)
bye("SSL_CTX_use_certificate_chain_file(): %s.", ERR_error_string(ERR_get_error(), NULL));
if (SSL_CTX_use_PrivateKey_file(sslctx, o.sslkey, SSL_FILETYPE_PEM) != 1)
bye("SSL_CTX_use_Privatekey_file(): %s.", ERR_error_string(ERR_get_error(), NULL));
}
done:
return sslctx;
}
