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-rw-r--r--src/proxy-polarssl.c360
1 files changed, 360 insertions, 0 deletions
diff --git a/src/proxy-polarssl.c b/src/proxy-polarssl.c
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+++ b/src/proxy-polarssl.c
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+/*
+ * proxy-polarssl.c - Net stack layer for SOCKS4a/5 proxy connections
+ *
+ * Based on proxy-bio.c - Original copyright (c) 2012 The Chromium OS Authors.
+ *
+ * This file was adapted by Paul Bakker <p.j.bakker@offspark.com>
+ * All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * This file implements a SOCKS4a/SOCKS5 net layer as used by PolarSSL.
+ */
+
+#include "config.h"
+
+#include <arpa/inet.h>
+#include <assert.h>
+#ifndef __USE_MISC
+#define __USE_MISC
+#endif
+#ifndef __USE_POSIX
+#define __USE_POSIX
+#endif
+#include <netdb.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#ifndef HAVE_STRNLEN
+#include "src/common/strnlen.h"
+#endif
+
+#include "src/proxy-polarssl.h"
+#include "src/util.h"
+
+int socks4a_connect(proxy_polarssl_ctx *ctx)
+{
+ int r;
+ unsigned char buf[NI_MAXHOST + 16];
+ uint16_t port_n;
+ size_t sz = 0;
+
+ if (!ctx)
+ return 0;
+
+ verb("V: proxy4: connecting %s:%d", ctx->host, ctx->port);
+
+ port_n = htons(ctx->port);
+
+ /*
+ * Packet layout:
+ * 1b: Version (must be 0x04)
+ * 1b: command (0x01 is connect)
+ * 2b: port number, big-endian
+ * 4b: 0x00, 0x00, 0x00, 0x01 (bogus IPv4 addr)
+ * 1b: 0x00 (empty 'userid' field)
+ * nb: hostname, null-terminated
+ */
+ buf[0] = 0x04;
+ buf[1] = 0x01;
+ sz += 2;
+
+ memcpy(buf + 2, &port_n, sizeof(port_n));
+ sz += sizeof(port_n);
+
+ buf[4] = 0x00;
+ buf[5] = 0x00;
+ buf[6] = 0x00;
+ buf[7] = 0x01;
+ sz += 4;
+
+ buf[8] = 0x00;
+ sz += 1;
+
+ memcpy(buf + sz, ctx->host, strlen(ctx->host) + 1);
+ sz += strlen(ctx->host) + 1;
+
+ r = ctx->f_send(ctx->p_send, buf, sz);
+ if (r != sz)
+ return 0;
+
+ /* server reply: 1 + 1 + 2 + 4 */
+ r = ctx->f_recv(ctx->p_recv, buf, 8);
+ if (r != 8)
+ return 0;
+
+ if (buf[1] == 0x5a) {
+ verb("V: proxy4: connected");
+ ctx->connected = 1;
+ return 1;
+ }
+ return 0;
+}
+
+int socks5_connect(proxy_polarssl_ctx *ctx)
+{
+ unsigned char buf[NI_MAXHOST + 16];
+ int r;
+ uint16_t port_n;
+ size_t sz = 0;
+
+ if (!ctx)
+ return 0;
+
+ /* the length for SOCKS addresses is only one byte. */
+ if (strnlen(ctx->host, UINT8_MAX + 1) == UINT8_MAX + 1)
+ return 0;
+
+ verb("V: proxy5: connecting %s:%d", ctx->host, ctx->port);
+
+ port_n = htons(ctx->port);
+
+ /*
+ * Hello packet layout:
+ * 1b: Version
+ * 1b: auth methods
+ * nb: method types
+ *
+ * We support only one method (no auth, 0x00). Others listed in RFC
+ * 1928.
+ */
+ buf[0] = 0x05;
+ buf[1] = 0x01;
+ buf[2] = 0x00;
+
+ r = ctx->f_send(ctx->p_send, buf, 3);
+ if (r != 3)
+ return 0;
+
+ r = ctx->f_recv(ctx->p_recv, buf, 2);
+ if (r != 2)
+ return 0;
+
+ if (buf[0] != 0x05 || buf[1] != 0x00) {
+ verb("V: proxy5: auth error %02x %02x", buf[0], buf[1]);
+ return 0;
+ }
+
+ /*
+ * Connect packet layout:
+ * 1b: version
+ * 1b: command (0x01 is connect)
+ * 1b: reserved, 0x00
+ * 1b: addr type (0x03 is domain name)
+ * nb: addr len (1b) + addr bytes, no null termination
+ * 2b: port, network byte order
+ */
+ buf[0] = 0x05;
+ buf[1] = 0x01;
+ buf[2] = 0x00;
+ buf[3] = 0x03;
+ buf[4] = strlen(ctx->host);
+ sz += 5;
+ memcpy(buf + 5, ctx->host, strlen(ctx->host));
+ sz += strlen(ctx->host);
+ memcpy(buf + sz, &port_n, sizeof(port_n));
+ sz += sizeof(port_n);
+
+ r = ctx->f_send(ctx->p_send, buf, sz);
+ if (r != sz)
+ return 0;
+
+ /*
+ * Server's response:
+ * 1b: version
+ * 1b: status (0x00 is okay)
+ * 1b: reserved, 0x00
+ * 1b: addr type (0x03 is domain name, 0x01 ipv4)
+ * nb: addr len (1b) + addr bytes, no null termination
+ * 2b: port, network byte order
+ */
+
+ /* grab up through the addr type */
+ r = ctx->f_recv(ctx->p_recv, buf, 4);
+ if (r != 4)
+ return 0;
+
+ if (buf[0] != 0x05 || buf[1] != 0x00) {
+ verb("V: proxy5: connect error %02x %02x", buf[0], buf[1]);
+ return 0;
+ }
+
+ if (buf[3] == 0x03) {
+ unsigned int len;
+ r = ctx->f_recv(ctx->p_recv, buf + 4, 1);
+ if (r != 1)
+ return 0;
+ /* host (buf[4] bytes) + port (2 bytes) */
+ len = buf[4] + 2;
+ while (len) {
+ r = ctx->f_recv(ctx->p_recv, buf + 5, min(len, sizeof(buf)));
+ if (r <= 0)
+ return 0;
+ len -= min(len, r);
+ }
+ } else if (buf[3] == 0x01) {
+ /* 4 bytes ipv4 addr, 2 bytes port */
+ r = ctx->f_recv(ctx->p_recv, buf + 4, 6);
+ if (r != 6)
+ return 0;
+ }
+
+ verb("V: proxy5: connected");
+ ctx->connected = 1;
+ return 1;
+}
+
+/* SSL socket BIOs don't support BIO_gets, so... */
+int sock_gets(proxy_polarssl_ctx *ctx, char *buf, size_t sz)
+{
+ unsigned char c;
+ while (ctx->f_recv(ctx->p_recv, &c, 1) > 0 && sz > 1) {
+ *buf++ = c;
+ sz--;
+ if (c == '\n') {
+ *buf = '\0';
+ return 0;
+ }
+ }
+ return 1;
+}
+
+int http_connect(proxy_polarssl_ctx *ctx)
+{
+ int r;
+ char buf[4096];
+ int retcode;
+
+ snprintf(buf, sizeof(buf), "CONNECT %s:%d HTTP/1.1\r\n",
+ ctx->host, ctx->port);
+ r = ctx->f_send(ctx->p_send, (unsigned char *) buf, strlen(buf));
+ if (r != strlen(buf))
+ return 0;
+ /* required by RFC 2616 14.23 */
+ snprintf(buf, sizeof(buf), "Host: %s:%d\r\n", ctx->host, ctx->port);
+ r = ctx->f_send(ctx->p_send, (unsigned char *) buf, strlen(buf));
+ if (r != strlen(buf))
+ return 0;
+ strcpy(buf, "\r\n");
+ r = ctx->f_send(ctx->p_send, (unsigned char *) buf, strlen(buf));
+ if (r != strlen(buf))
+ return 0;
+
+ r = sock_gets(ctx, buf, sizeof(buf));
+ if (r)
+ return 0;
+ /* use %*s to ignore the version */
+ if (sscanf(buf, "HTTP/%*s %d", &retcode) != 1)
+ return 0;
+
+ if (retcode < 200 || retcode > 299)
+ return 0;
+ while (!(r = sock_gets(ctx, buf, sizeof(buf)))) {
+ if (!strcmp(buf, "\r\n")) {
+ /* Done with the header */
+ ctx->connected = 1;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+int API proxy_polarssl_init(proxy_polarssl_ctx *ctx)
+{
+ if (!ctx)
+ return 0;
+
+ memset(ctx, 0, sizeof(proxy_polarssl_ctx));
+ return 1;
+}
+
+void API proxy_polarssl_set_bio(proxy_polarssl_ctx *ctx,
+ int (*f_recv)(void *, unsigned char *, size_t), void *p_recv,
+ int (*f_send)(void *, const unsigned char *, size_t), void *p_send)
+{
+ if (!ctx)
+ return;
+
+ ctx->f_recv = f_recv;
+ ctx->p_recv = p_recv;
+ ctx->f_send = f_send;
+ ctx->p_send = p_send;
+}
+
+int API proxy_polarssl_free(proxy_polarssl_ctx *ctx)
+{
+ if (!ctx)
+ return 0;
+
+ if (ctx->host)
+ {
+ free(ctx->host);
+ ctx->host = NULL;
+ }
+
+ return 1;
+}
+
+int API proxy_polarssl_set_scheme(proxy_polarssl_ctx *ctx, const char *scheme)
+{
+ if (!strcmp(scheme, "socks5"))
+ ctx->f_connect = socks5_connect;
+ else if (!strcmp(scheme, "socks4"))
+ ctx->f_connect = socks4a_connect;
+ else if (!strcmp(scheme, "http"))
+ ctx->f_connect = http_connect;
+ else
+ return 1;
+ return 0;
+}
+
+int API proxy_polarssl_set_host(proxy_polarssl_ctx *ctx, const char *host)
+{
+ if (strnlen(host, NI_MAXHOST) == NI_MAXHOST)
+ return 1;
+ ctx->host = strdup(host);
+ return 0;
+}
+
+void API proxy_polarssl_set_port(proxy_polarssl_ctx *ctx, uint16_t port)
+{
+ ctx->port = port;
+}
+
+int API proxy_polarssl_recv(void *ctx, unsigned char *data, size_t len)
+{
+ proxy_polarssl_ctx *proxy = (proxy_polarssl_ctx *) ctx;
+ int r;
+
+ if (!ctx)
+ return -1;
+
+ if (!proxy->connected)
+ {
+ r = proxy->f_connect(ctx);
+ if (r)
+ return (r);
+ }
+
+ return proxy->f_recv(proxy->p_recv, data, len);
+}
+
+
+int API proxy_polarssl_send(void *ctx, const unsigned char *data, size_t len)
+{
+ proxy_polarssl_ctx *proxy = (proxy_polarssl_ctx *) ctx;
+ int r;
+
+ if (!ctx)
+ return -1;
+
+ if (!proxy->connected)
+ {
+ r = proxy->f_connect(ctx);
+ if (r)
+ return (r);
+ }
+
+ return proxy->f_send(proxy->p_send, data, len);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-25 15:07:38 +0000