1 files changed, 474 insertions, 0 deletions
diff --git a/tls_client.c b/tls_client.c
new file mode 100644
index 0000000..04e4402
--- /dev/null
+++ b/tls_client.c
@@ -0,0 +1,474 @@
+/* $OpenBSD: tls_client.c,v 1.45 2018/03/19 16:34:47 jsing 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 <sys/types.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+#include <limits.h>
+#include <netdb.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <openssl/err.h>
+#include <openssl/x509.h>
+
+#include <tls.h>
+#include "tls_internal.h"
+
+struct tls *
+tls_client(void)
+{
+	struct tls *ctx;
+
+	if (tls_init() == -1)
+		return (NULL);
+
+	if ((ctx = tls_new()) == NULL)
+		return (NULL);
+
+	ctx->flags |= TLS_CLIENT;
+
+	return (ctx);
+}
+
+int
+tls_connect(struct tls *ctx, const char *host, const char *port)
+{
+	return tls_connect_servername(ctx, host, port, NULL);
+}
+
+int
+tls_connect_servername(struct tls *ctx, const char *host, const char *port,
+    const char *servername)
+{
+	struct addrinfo hints, *res, *res0;
+	const char *h = NULL, *p = NULL;
+	char *hs = NULL, *ps = NULL;
+	int rv = -1, s = -1, ret;
+
+	if ((ctx->flags & TLS_CLIENT) == 0) {
+		tls_set_errorx(ctx, "not a client context");
+		goto err;
+	}
+
+	if (host == NULL) {
+		tls_set_errorx(ctx, "host not specified");
+		goto err;
+	}
+
+	/*
+	 * If port is NULL try to extract a port from the specified host,
+	 * otherwise use the default.
+	 */
+	if ((p = (char *)port) == NULL) {
+		ret = tls_host_port(host, &hs, &ps);
+		if (ret == -1) {
+			tls_set_errorx(ctx, "memory allocation failure");
+			goto err;
+		}
+		if (ret != 0) {
+			tls_set_errorx(ctx, "no port provided");
+			goto err;
+		}
+	}
+
+	h = (hs != NULL) ? hs : host;
+	p = (ps != NULL) ? ps : port;
+
+	/*
+	 * First check if the host is specified as a numeric IP address,
+	 * either IPv4 or IPv6, before trying to resolve the host.
+	 * The AI_ADDRCONFIG resolver option will not return IPv4 or IPv6
+	 * records if it is not configured on an interface;  not considering
+	 * loopback addresses.  Checking the numeric addresses first makes
+	 * sure that connection attempts to numeric addresses and especially
+	 * 127.0.0.1 or ::1 loopback addresses are always possible.
+	 */
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_socktype = SOCK_STREAM;
+
+	/* try as an IPv4 literal */
+	hints.ai_family = AF_INET;
+	hints.ai_flags = AI_NUMERICHOST;
+	if (getaddrinfo(h, p, &hints, &res0) != 0) {
+		/* try again as an IPv6 literal */
+		hints.ai_family = AF_INET6;
+		if (getaddrinfo(h, p, &hints, &res0) != 0) {
+			/* last try, with name resolution and save the error */
+			hints.ai_family = AF_UNSPEC;
+			hints.ai_flags = AI_ADDRCONFIG;
+			if ((s = getaddrinfo(h, p, &hints, &res0)) != 0) {
+				tls_set_error(ctx, "%s", gai_strerror(s));
+				goto err;
+			}
+		}
+	}
+
+	/* It was resolved somehow; now try connecting to what we got */
+	s = -1;
+	for (res = res0; res; res = res->ai_next) {
+		s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+		if (s == -1) {
+			tls_set_error(ctx, "socket");
+			continue;
+		}
+		if (connect(s, res->ai_addr, res->ai_addrlen) == -1) {
+			tls_set_error(ctx, "connect");
+			close(s);
+			s = -1;
+			continue;
+		}
+
+		break;  /* Connected. */
+	}
+	freeaddrinfo(res0);
+
+	if (s == -1)
+		goto err;
+
+	if (servername == NULL)
+		servername = h;
+
+	if (tls_connect_socket(ctx, s, servername) != 0) {
+		close(s);
+		goto err;
+	}
+
+	ctx->socket = s;
+
+	rv = 0;
+
+ err:
+	free(hs);
+	free(ps);
+
+	return (rv);
+}
+
+static int
+tls_client_read_session(struct tls *ctx)
+{
+	int sfd = ctx->config->session_fd;
+	uint8_t *session = NULL;
+	size_t session_len = 0;
+	SSL_SESSION *ss = NULL;
+	BIO *bio = NULL;
+	struct stat sb;
+	ssize_t n;
+	int rv = -1;
+
+	if (fstat(sfd, &sb) == -1) {
+		tls_set_error(ctx, "failed to stat session file");
+		goto err;
+	}
+	if (sb.st_size < 0 || sb.st_size > INT_MAX) {
+		tls_set_errorx(ctx, "invalid session file size");
+		goto err;
+	}
+	session_len = (size_t)sb.st_size;
+
+	/* A zero size file means that we do not yet have a valid session. */
+	if (session_len == 0)
+		goto done;
+
+	if ((session = malloc(session_len)) == NULL)
+		goto err;
+
+	n = pread(sfd, session, session_len, 0);
+	if (n < 0 || (size_t)n != session_len) {
+		tls_set_error(ctx, "failed to read session file");
+		goto err;
+	}
+	if ((bio = BIO_new_mem_buf(session, session_len)) == NULL)
+		goto err;
+	if ((ss = PEM_read_bio_SSL_SESSION(bio, NULL, tls_password_cb,
+	    NULL)) == NULL) {
+		tls_set_errorx(ctx, "failed to parse session");
+		goto err;
+	}
+
+	if (SSL_set_session(ctx->ssl_conn, ss) != 1) {
+		tls_set_errorx(ctx, "failed to set session");
+		goto err;
+	}
+
+ done:
+	rv = 0;
+
+ err:
+	freezero(session, session_len);
+	SSL_SESSION_free(ss);
+	BIO_free(bio);
+
+	return rv;
+}
+
+static int
+tls_client_write_session(struct tls *ctx)
+{
+	int sfd = ctx->config->session_fd;
+	SSL_SESSION *ss = NULL;
+	BIO *bio = NULL;
+	long data_len;
+	char *data;
+	off_t offset;
+	size_t len;
+	ssize_t n;
+	int rv = -1;
+
+	if ((ss = SSL_get1_session(ctx->ssl_conn)) == NULL) {
+		if (ftruncate(sfd, 0) == -1) {
+			tls_set_error(ctx, "failed to truncate session file");
+			goto err;
+		}
+		goto done;
+	}
+
+	if ((bio = BIO_new(BIO_s_mem())) == NULL)
+		goto err;
+	if (PEM_write_bio_SSL_SESSION(bio, ss) == 0)
+		goto err;
+	if ((data_len = BIO_get_mem_data(bio, &data)) <= 0)
+		goto err;
+
+	len = (size_t)data_len;
+	offset = 0;
+
+	if (ftruncate(sfd, len) == -1) {
+		tls_set_error(ctx, "failed to truncate session file");
+		goto err;
+	}
+	while (len > 0) {
+		if ((n = pwrite(sfd, data + offset, len, offset)) == -1) {
+			tls_set_error(ctx, "failed to write session file");
+			goto err;
+		}
+		offset += n;
+		len -= n;
+	}
+
+ done:
+	rv = 0;
+
+ err:
+	SSL_SESSION_free(ss);
+	BIO_free_all(bio);
+
+	return (rv);
+}
+
+static int
+tls_connect_common(struct tls *ctx, const char *servername)
+{
+	union tls_addr addrbuf;
+	int rv = -1;
+
+	if ((ctx->flags & TLS_CLIENT) == 0) {
+		tls_set_errorx(ctx, "not a client context");
+		goto err;
+	}
+
+	if (servername != NULL) {
+		if ((ctx->servername = strdup(servername)) == NULL) {
+			tls_set_errorx(ctx, "out of memory");
+			goto err;
+		}
+	}
+
+	if ((ctx->ssl_ctx = SSL_CTX_new(SSLv23_client_method())) == NULL) {
+		tls_set_errorx(ctx, "ssl context failure");
+		goto err;
+	}
+
+	if (tls_configure_ssl(ctx, ctx->ssl_ctx) != 0)
+		goto err;
+
+	if (tls_configure_ssl_keypair(ctx, ctx->ssl_ctx,
+	    ctx->config->keypair, 0) != 0)
+		goto err;
+
+	if (ctx->config->verify_name) {
+		if (servername == NULL) {
+			tls_set_errorx(ctx, "server name not specified");
+			goto err;
+		}
+	}
+
+	if (tls_configure_ssl_verify(ctx, ctx->ssl_ctx, SSL_VERIFY_PEER) == -1)
+		goto err;
+
+	if (ctx->config->ecdhecurves != NULL) {
+		if (SSL_CTX_set1_groups(ctx->ssl_ctx, ctx->config->ecdhecurves,
+		    ctx->config->ecdhecurves_len) != 1) {
+			tls_set_errorx(ctx, "failed to set ecdhe curves");
+			goto err;
+		}
+	}
+
+	if (SSL_CTX_set_tlsext_status_cb(ctx->ssl_ctx, tls_ocsp_verify_cb) != 1) {
+		tls_set_errorx(ctx, "ssl OCSP verification setup failure");
+		goto err;
+	}
+
+	if ((ctx->ssl_conn = SSL_new(ctx->ssl_ctx)) == NULL) {
+		tls_set_errorx(ctx, "ssl connection failure");
+		goto err;
+	}
+
+	if (SSL_set_app_data(ctx->ssl_conn, ctx) != 1) {
+		tls_set_errorx(ctx, "ssl application data failure");
+		goto err;
+	}
+
+	if (ctx->config->session_fd != -1) {
+		SSL_clear_options(ctx->ssl_conn, SSL_OP_NO_TICKET);
+		if (tls_client_read_session(ctx) == -1)
+			goto err;
+	}
+
+	if (SSL_set_tlsext_status_type(ctx->ssl_conn, TLSEXT_STATUSTYPE_ocsp) != 1) {
+		tls_set_errorx(ctx, "ssl OCSP extension setup failure");
+		goto err;
+	}
+
+	/*
+	 * RFC4366 (SNI): Literal IPv4 and IPv6 addresses are not
+	 * permitted in "HostName".
+	 */
+	if (servername != NULL &&
+	    inet_pton(AF_INET, servername, &addrbuf) != 1 &&
+	    inet_pton(AF_INET6, servername, &addrbuf) != 1) {
+		if (SSL_set_tlsext_host_name(ctx->ssl_conn, servername) == 0) {
+			tls_set_errorx(ctx, "server name indication failure");
+			goto err;
+		}
+	}
+
+	ctx->state |= TLS_CONNECTED;
+	rv = 0;
+
+ err:
+	return (rv);
+}
+
+int
+tls_connect_socket(struct tls *ctx, int s, const char *servername)
+{
+	return tls_connect_fds(ctx, s, s, servername);
+}
+
+int
+tls_connect_fds(struct tls *ctx, int fd_read, int fd_write,
+    const char *servername)
+{
+	int rv = -1;
+
+	if (fd_read < 0 || fd_write < 0) {
+		tls_set_errorx(ctx, "invalid file descriptors");
+		goto err;
+	}
+
+	if (tls_connect_common(ctx, servername) != 0)
+		goto err;
+
+	if (SSL_set_rfd(ctx->ssl_conn, fd_read) != 1 ||
+	    SSL_set_wfd(ctx->ssl_conn, fd_write) != 1) {
+		tls_set_errorx(ctx, "ssl file descriptor failure");
+		goto err;
+	}
+
+	rv = 0;
+ err:
+	return (rv);
+}
+
+int
+tls_connect_cbs(struct tls *ctx, tls_read_cb read_cb,
+    tls_write_cb write_cb, void *cb_arg, const char *servername)
+{
+	int rv = -1;
+
+	if (tls_connect_common(ctx, servername) != 0)
+		goto err;
+
+	if (tls_set_cbs(ctx, read_cb, write_cb, cb_arg) != 0)
+		goto err;
+
+	rv = 0;
+
+ err:
+	return (rv);
+}
+
+int
+tls_handshake_client(struct tls *ctx)
+{
+	X509 *cert = NULL;
+	int match, ssl_ret;
+	int rv = -1;
+
+	if ((ctx->flags & TLS_CLIENT) == 0) {
+		tls_set_errorx(ctx, "not a client context");
+		goto err;
+	}
+
+	if ((ctx->state & TLS_CONNECTED) == 0) {
+		tls_set_errorx(ctx, "context not connected");
+		goto err;
+	}
+
+	ctx->state |= TLS_SSL_NEEDS_SHUTDOWN;
+
+	ERR_clear_error();
+	if ((ssl_ret = SSL_connect(ctx->ssl_conn)) != 1) {
+		rv = tls_ssl_error(ctx, ctx->ssl_conn, ssl_ret, "handshake");
+		goto err;
+	}
+
+	if (ctx->config->verify_name) {
+		cert = SSL_get_peer_certificate(ctx->ssl_conn);
+		if (cert == NULL) {
+			tls_set_errorx(ctx, "no server certificate");
+			goto err;
+		}
+		if (tls_check_name(ctx, cert, ctx->servername, &match) == -1)
+			goto err;
+		if (!match) {
+			tls_set_errorx(ctx, "name `%s' not present in"
+			    " server certificate", ctx->servername);
+			goto err;
+		}
+	}
+
+	ctx->state |= TLS_HANDSHAKE_COMPLETE;
+
+	if (ctx->config->session_fd != -1) {
+		if (tls_client_write_session(ctx) == -1)
+			goto err;
+	}
+
+	rv = 0;
+
+ err:
+	X509_free(cert);
+
+	return (rv);
+}