sacc

commit c3bb55bb797cb476a5f26b148e1572521e389313
parent eae2a995544b2b48c3a7debcb186a00aa0c400b3
Author: parazyd <parazyd@dyne.org>
Date:   Tue,  6 Apr 2021 13:24:32 +0200

Add support for Gopher over TLS.

This implementation uses libtls and acts on gophers:// URIs.

Diffstat:
M
config.mk
 | 
4
++++
M
sacc.c
 | 
72
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------
A
tls.h
 | 
15
+++++++++++++++

3 files changed, 81 insertions(+), 10 deletions(-)
diff --git a/config.mk b/config.mk
@@ -12,3 +12,7 @@ LIBS=-lcurses
 # Define NEED_ASPRINTF and/or NEED_STRCASESTR in your cflags if your system does
 # not provide asprintf() or strcasestr(), respectively.
 #CFLAGS = -DNEED_ASPRINTF -DNEED_STRCASESTR
+
+# Define USE_TLS if you want Gopher over TLS support as gophers:// URIs
+#CFLAGS = -DUSE_TLS
+#LIBS = -lcurses -ltls
diff --git a/sacc.c b/sacc.c
@@ -19,6 +19,7 @@
 #include <sys/wait.h>
 
 #include "common.h"
+#include "tls.h"
 
 #include "config.h"
 
@@ -27,6 +28,8 @@ static Item *mainentry;
 static int devnullfd;
 static int parent = 1;
 static int interactive;
+static int dotls = 0;
+static struct tls *tlsctx = NULL;
 
 static void (*diag)(char *fmt, ...);
 
@@ -54,6 +57,40 @@ die(const char *fmt, ...)
 	exit(1);
 }
 
+static ssize_t
+read_wrap(int s, void *buf, size_t bs)
+{
+	if (tlsctx) {
+		ssize_t r = TLS_WANT_POLLIN;
+		while (r == TLS_WANT_POLLIN || r == TLS_WANT_POLLOUT)
+			r = tls_read(tlsctx, buf, bs);
+		return r;
+	}
+	return read(s, buf, bs);
+}
+
+static ssize_t
+write_wrap(int fd, const void *buf, size_t nbyte)
+{
+	if (tlsctx) {
+		ssize_t r = TLS_WANT_POLLIN;
+		while (r == TLS_WANT_POLLIN || r == TLS_WANT_POLLOUT)
+			r = tls_write(tlsctx, buf, nbyte);
+		return r;
+	}
+	return write(fd, buf, nbyte);
+}
+
+static int
+close_wrap(int fd)
+{
+	if (tlsctx) {
+		tls_close(tlsctx);
+		tls_reset(tlsctx);
+	}
+	return close(fd);
+}
+
 #ifdef NEED_ASPRINTF
 int
 asprintf(char **s, const char *fmt, ...)
@@ -435,18 +472,20 @@ getrawitem(int sock)
 			buf = raw + (bn-1) * BUFSIZ;
 			bs = BUFSIZ;
 		}
-	} while ((n = read(sock, buf, bs)) > 0);
+	} while ((n = read_wrap(sock, buf, bs)) > 0);
 
 	*buf = '\0';
 
 	if (n < 0) {
-		diag("Can't read socket: %s", strerror(errno));
+		diag("Can't read socket: %s",
+		     tlsctx ? tls_error(tlsctx) : strerror(errno));
 		clear(&raw);
 	}
 
 	return raw;
 }
 
+
 static int
 sendselector(int sock, const char *selector)
 {
@@ -458,14 +497,15 @@ sendselector(int sock, const char *selector)
 	msg = p = xmalloc(ln);
 	snprintf(msg, ln--, "%s\r\n", selector);
 
-	while ((n = write(sock, p, ln)) > 0) {
+	while ((n = write_wrap(sock, p, ln)) > 0) {
 		ln -= n;
 		p += n;
 	}
 
 	free(msg);
 	if (n == -1)
-		diag("Can't send message: %s", strerror(errno));
+		diag("Can't send message: %s",
+		     tlsctx ? tls_error(tlsctx) : strerror(errno));
 
 	return n;
 }
@@ -480,7 +520,7 @@ connectto(const char *host, const char *port)
 	    .ai_protocol = IPPROTO_TCP,
 	};
 	struct addrinfo *addrs, *addr;
-	int r, sock = -1;
+	int r, t = 0, sock = -1;
 
 	sigemptyset(&set);
 	sigaddset(&set, SIGWINCH);
@@ -497,9 +537,13 @@ connectto(const char *host, const char *port)
 		                   addr->ai_protocol)) < 0)
 			continue;
 		if ((r = connect(sock, addr->ai_addr, addr->ai_addrlen)) < 0) {
-			close(sock);
+			close_wrap(sock);
 			continue;
 		}
+		if (dotls) {
+			tlsctx = tls_client();
+			t = tls_connect_socket(tlsctx, sock, host);
+		}
 		break;
 	}
 
@@ -514,6 +558,10 @@ connectto(const char *host, const char *port)
 		     host, port, strerror(errno));
 		goto err;
 	}
+	if (t < 0) {
+		diag("Can't init TLS : %s", tls_error(tlsctx));
+		goto err;
+	}
 
 	sigprocmask(SIG_SETMASK, &oset, NULL);
 	return sock;
@@ -542,7 +590,7 @@ download(Item *item, int dest)
 	}
 
 	w = 0;
-	while ((r = read(src, buf, BUFSIZ)) > 0) {
+	while ((r = read_wrap(src, buf, BUFSIZ)) > 0) {
 		while ((w = write(dest, buf, r)) > 0)
 			r -= w;
 	}
@@ -553,7 +601,7 @@ download(Item *item, int dest)
 		errno = 0;
 	}
 
-	close(src);
+	close_wrap(src);
 
 	return (r == 0 && w == 0);
 }
@@ -615,7 +663,7 @@ fetchitem(Item *item)
 	    sendselector(sock, item->selector) < 0)
 		return 0;
 	raw = getrawitem(sock);
-	close(sock);
+	close_wrap(sock);
 
 	if (raw == NULL || !*raw) {
 		diag("Empty response from server");
@@ -900,7 +948,11 @@ moldentry(char *url)
 	int parsed, ipv6;
 
 	if (p = strstr(url, "://")) {
-		if (strncmp(url, "gopher", p - url))
+		if (!strncmp(url, "gopher", p - url))
+			dotls = 0;
+		else if (!strncmp(url, "gophers", p - url))
+			dotls = 1;
+		else
 			die("Protocol not supported: %.*s", p - url, url);
 		host = p + 3;
 	}
diff --git a/tls.h b/tls.h
@@ -0,0 +1,15 @@
+/* See LICENSE file for copyright and license details. */
+#ifndef USE_TLS
+
+#define TLS_WANT_POLLIN  0
+#define TLS_WANT_POLLOUT 0
+#define tls_read(a,b,c)  0
+#define tls_write(a,b,c) 0
+#define tls_close(a)     0
+#define tls_reset(a)     0
+#define tls_error(a)     0
+#define tls_client()     0
+#define tls_connect_socket(a,b,c) 0
+#else
+#include <tls.h>
+#endif