X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/1549e076bc8f485888261a3b97ce35e442b5fda9..7bd029472d96162f71f61df67baedc00fc0bb1a8:/proxy.c diff --git a/proxy.c b/proxy.c index f73b9ad1..2ea0bc8c 100644 --- a/proxy.c +++ b/proxy.c @@ -5,13 +5,19 @@ * code and the higher level backend. */ -#include +#include +#include +#include #define DEFINE_PLUG_METHOD_MACROS #include "putty.h" #include "network.h" #include "proxy.h" +#define do_proxy_dns(cfg) \ + (cfg->proxy_dns == FORCE_ON || \ + (cfg->proxy_dns == AUTO && cfg->proxy_type != PROXY_SOCKS)) + /* * Call this when proxy negotiation is complete, so that this * socket can begin working normally. @@ -20,43 +26,50 @@ void proxy_activate (Proxy_Socket p) { void *data; int len; - + long output_before, output_after; + p->state = PROXY_STATE_ACTIVE; - /* let's try to keep extra receive events from coming through */ + /* we want to ignore new receive events until we have sent + * all of our buffered receive data. + */ sk_set_frozen(p->sub_socket, 1); + /* how many bytes of output have we buffered? */ + output_before = bufchain_size(&p->pending_oob_output_data) + + bufchain_size(&p->pending_output_data); + /* and keep track of how many bytes do not get sent. */ + output_after = 0; + /* send buffered OOB writes */ while (bufchain_size(&p->pending_oob_output_data) > 0) { bufchain_prefix(&p->pending_oob_output_data, &data, &len); - sk_write_oob(p->sub_socket, data, len); + output_after += sk_write_oob(p->sub_socket, data, len); bufchain_consume(&p->pending_oob_output_data, len); } - bufchain_clear(&p->pending_oob_output_data); /* send buffered normal writes */ while (bufchain_size(&p->pending_output_data) > 0) { bufchain_prefix(&p->pending_output_data, &data, &len); - sk_write(p->sub_socket, data, len); + output_after += sk_write(p->sub_socket, data, len); bufchain_consume(&p->pending_output_data, len); } - bufchain_clear(&p->pending_output_data); + + /* if we managed to send any data, let the higher levels know. */ + if (output_after < output_before) + plug_sent(p->plug, output_after); /* if we were asked to flush the output during * the proxy negotiation process, do so now. */ if (p->pending_flush) sk_flush(p->sub_socket); - /* forward buffered recv data to the backend */ - while (bufchain_size(&p->pending_input_data) > 0) { - bufchain_prefix(&p->pending_input_data, &data, &len); - plug_receive(p->plug, 0, data, len); - bufchain_consume(&p->pending_input_data, len); - } - bufchain_clear(&p->pending_input_data); - - /* now set the underlying socket to whatever freeze state they wanted */ - sk_set_frozen(p->sub_socket, p->freeze); + /* if the backend wanted the socket unfrozen, try to unfreeze. + * our set_frozen handler will flush buffered receive data before + * unfreezing the actual underlying socket. + */ + if (!p->freeze) + sk_set_frozen((Socket)p, 0); } /* basic proxy socket functions */ @@ -78,7 +91,7 @@ static void sk_proxy_close (Socket s) sfree(ps); } -static int sk_proxy_write (Socket s, char *data, int len) +static int sk_proxy_write (Socket s, const char *data, int len) { Proxy_Socket ps = (Proxy_Socket) s; @@ -89,7 +102,7 @@ static int sk_proxy_write (Socket s, char *data, int len) return sk_write(ps->sub_socket, data, len); } -static int sk_proxy_write_oob (Socket s, char *data, int len) +static int sk_proxy_write_oob (Socket s, const char *data, int len) { Proxy_Socket ps = (Proxy_Socket) s; @@ -133,6 +146,30 @@ static void sk_proxy_set_frozen (Socket s, int is_frozen) ps->freeze = is_frozen; return; } + + /* handle any remaining buffered recv data first */ + if (bufchain_size(&ps->pending_input_data) > 0) { + ps->freeze = is_frozen; + + /* loop while we still have buffered data, and while we are + * unfrozen. the plug_receive call in the loop could result + * in a call back into this function refreezing the socket, + * so we have to check each time. + */ + while (!ps->freeze && bufchain_size(&ps->pending_input_data) > 0) { + void *data; + int len; + bufchain_prefix(&ps->pending_input_data, &data, &len); + plug_receive(ps->plug, 0, data, len); + bufchain_consume(&ps->pending_input_data, len); + } + + /* if we're still frozen, we'll have to wait for another + * call from the backend to finish unbuffering the data. + */ + if (ps->freeze) return; + } + sk_set_frozen(ps->sub_socket, is_frozen); } @@ -207,20 +244,37 @@ static int plug_proxy_accepting (Plug p, void *sock) return plug_accepting(ps->plug, sock); } -static int proxy_for_destination (SockAddr addr, char * hostname, int port) +/* + * This function can accept a NULL pointer as `addr', in which case + * it will only check the host name. + */ +static int proxy_for_destination (SockAddr addr, char *hostname, int port, + const Config *cfg) { int s = 0, e = 0; char hostip[64]; int hostip_len, hostname_len; - char * exclude_list; + const char *exclude_list; + + /* + * Check the host name and IP against the hard-coded + * representations of `localhost'. + */ + if (!cfg->even_proxy_localhost && + (sk_hostname_is_local(hostname) || + (addr && sk_address_is_local(addr)))) + return 0; /* do not proxy */ /* we want a string representation of the IP address for comparisons */ - sk_getaddr(addr, hostip, 64); + if (addr) { + sk_getaddr(addr, hostip, 64); + hostip_len = strlen(hostip); + } else + hostip_len = 0; /* placate gcc; shouldn't be required */ - hostip_len = strlen(hostip); hostname_len = strlen(hostname); - exclude_list = cfg.proxy_exclude_list; + exclude_list = cfg->proxy_exclude_list; /* now parse the exclude list, and see if either our IP * or hostname matches anything in it. @@ -228,7 +282,7 @@ static int proxy_for_destination (SockAddr addr, char * hostname, int port) while (exclude_list[s]) { while (exclude_list[s] && - (isspace(exclude_list[s]) || + (isspace((unsigned char)exclude_list[s]) || exclude_list[s] == ',')) s++; if (!exclude_list[s]) break; @@ -236,7 +290,7 @@ static int proxy_for_destination (SockAddr addr, char * hostname, int port) e = s; while (exclude_list[e] && - (isalnum(exclude_list[e]) || + (isalnum((unsigned char)exclude_list[e]) || exclude_list[e] == '-' || exclude_list[e] == '.' || exclude_list[e] == '*')) e++; @@ -244,8 +298,8 @@ static int proxy_for_destination (SockAddr addr, char * hostname, int port) if (exclude_list[s] == '*') { /* wildcard at beginning of entry */ - if (strnicmp(hostip + hostip_len - (e - s - 1), - exclude_list + s + 1, e - s - 1) == 0 || + if ((addr && strnicmp(hostip + hostip_len - (e - s - 1), + exclude_list + s + 1, e - s - 1) == 0) || strnicmp(hostname + hostname_len - (e - s - 1), exclude_list + s + 1, e - s - 1) == 0) return 0; /* IP/hostname range excluded. do not use proxy. */ @@ -253,7 +307,7 @@ static int proxy_for_destination (SockAddr addr, char * hostname, int port) } else if (exclude_list[e-1] == '*') { /* wildcard at end of entry */ - if (strnicmp(hostip, exclude_list + s, e - s - 1) == 0 || + if ((addr && strnicmp(hostip, exclude_list + s, e - s - 1) == 0) || strnicmp(hostname, exclude_list + s, e - s - 1) == 0) return 0; /* IP/hostname range excluded. do not use proxy. */ @@ -262,24 +316,43 @@ static int proxy_for_destination (SockAddr addr, char * hostname, int port) * match (ie. a specific IP) */ - if (stricmp(hostip, exclude_list + s) == 0) + if (addr && stricmp(hostip, exclude_list + s) == 0) return 0; /* IP/hostname excluded. do not use proxy. */ if (stricmp(hostname, exclude_list + s) == 0) return 0; /* IP/hostname excluded. do not use proxy. */ } s = e; + + /* Make sure we really have reached the next comma or end-of-string */ + while (exclude_list[s] && + !isspace((unsigned char)exclude_list[s]) && + exclude_list[s] != ',') s++; } /* no matches in the exclude list, so use the proxy */ return 1; } +SockAddr name_lookup(char *host, int port, char **canonicalname, + const Config *cfg) +{ + if (cfg->proxy_type != PROXY_NONE && + do_proxy_dns(cfg) && + proxy_for_destination(NULL, host, port, cfg)) { + *canonicalname = dupstr(host); + return sk_nonamelookup(host); + } + + return sk_namelookup(host, canonicalname); +} + Socket new_connection(SockAddr addr, char *hostname, int port, int privport, - int oobinline, int nodelay, Plug plug) + int oobinline, int nodelay, Plug plug, + const Config *cfg) { - static struct socket_function_table socket_fn_table = { + static const struct socket_function_table socket_fn_table = { sk_proxy_plug, sk_proxy_close, sk_proxy_write, @@ -291,63 +364,73 @@ Socket new_connection(SockAddr addr, char *hostname, sk_proxy_socket_error }; - static struct plug_function_table plug_fn_table = { + static const struct plug_function_table plug_fn_table = { plug_proxy_closing, plug_proxy_receive, plug_proxy_sent, plug_proxy_accepting }; - if (cfg.proxy_type != PROXY_NONE && - proxy_for_destination(addr, hostname, port)) + if (cfg->proxy_type != PROXY_NONE && + proxy_for_destination(addr, hostname, port, cfg)) { Proxy_Socket ret; Proxy_Plug pplug; SockAddr proxy_addr; - char * proxy_canonical_name; + char *proxy_canonical_name, *err; - ret = smalloc(sizeof(struct Socket_proxy_tag)); + ret = snew(struct Socket_proxy_tag); ret->fn = &socket_fn_table; + ret->cfg = *cfg; /* STRUCTURE COPY */ ret->plug = plug; ret->remote_addr = addr; ret->remote_port = port; + ret->error = NULL; + ret->pending_flush = 0; + ret->freeze = 0; + bufchain_init(&ret->pending_input_data); bufchain_init(&ret->pending_output_data); bufchain_init(&ret->pending_oob_output_data); ret->sub_socket = NULL; ret->state = PROXY_STATE_NEW; - - if (cfg.proxy_type == PROXY_HTTP) { + ret->negotiate = NULL; + + if (cfg->proxy_type == PROXY_HTTP) { ret->negotiate = proxy_http_negotiate; - } else if (cfg.proxy_type == PROXY_SOCKS) { - if (cfg.proxy_socks_version == 4) + } else if (cfg->proxy_type == PROXY_SOCKS) { + if (cfg->proxy_socks_version == 4) ret->negotiate = proxy_socks4_negotiate; else ret->negotiate = proxy_socks5_negotiate; - } else if (cfg.proxy_type == PROXY_TELNET) { + } else if (cfg->proxy_type == PROXY_TELNET) { ret->negotiate = proxy_telnet_negotiate; } else { - ret->error = "Network error: Unknown proxy method"; + ret->error = "Proxy error: Unknown proxy method"; return (Socket) ret; } /* create the proxy plug to map calls from the actual * socket into our proxy socket layer */ - pplug = smalloc(sizeof(struct Plug_proxy_tag)); + pplug = snew(struct Plug_proxy_tag); pplug->fn = &plug_fn_table; pplug->proxy_socket = ret; /* look-up proxy */ - proxy_addr = sk_namelookup(cfg.proxy_host, + proxy_addr = sk_namelookup(cfg->proxy_host, &proxy_canonical_name); + if ((err = sk_addr_error(proxy_addr)) != NULL) { + ret->error = "Proxy error: Unable to resolve proxy host name"; + return (Socket)ret; + } sfree(proxy_canonical_name); /* create the actual socket we will be using, * connected to our proxy server and port. */ - ret->sub_socket = sk_new(proxy_addr, cfg.proxy_port, + ret->sub_socket = sk_new(proxy_addr, cfg->proxy_port, privport, oobinline, nodelay, (Plug) pplug); if (sk_socket_error(ret->sub_socket) != NULL) @@ -366,13 +449,14 @@ Socket new_connection(SockAddr addr, char *hostname, return sk_new(addr, port, privport, oobinline, nodelay, plug); } -Socket new_listener(int port, Plug plug, int local_host_only) +Socket new_listener(char *srcaddr, int port, Plug plug, int local_host_only, + const Config *cfg) { /* TODO: SOCKS (and potentially others) support inbound * TODO: connections via the proxy. support them. */ - return sk_newlistener(port, plug, local_host_only); + return sk_newlistener(srcaddr, port, plug, local_host_only); } /* ---------------------------------------------------------------------- @@ -421,29 +505,30 @@ int proxy_http_negotiate (Proxy_Socket p, int change) * for this proxy method, it's just a simple HTTP * request */ - char buf[256], dest[64]; + char *buf, dest[512]; - sk_getaddr(p->remote_addr, dest, 64); + sk_getaddr(p->remote_addr, dest, lenof(dest)); - sprintf(buf, "CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n", - dest, p->remote_port, dest, p->remote_port); + buf = dupprintf("CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n", + dest, p->remote_port, dest, p->remote_port); sk_write(p->sub_socket, buf, strlen(buf)); + sfree(buf); - if (cfg.proxy_username[0] || cfg.proxy_password[0]) { - char buf[sizeof(cfg.proxy_username)+sizeof(cfg.proxy_password)]; + if (p->cfg.proxy_username[0] || p->cfg.proxy_password[0]) { + char buf[sizeof(p->cfg.proxy_username)+sizeof(p->cfg.proxy_password)]; char buf2[sizeof(buf)*4/3 + 100]; int i, j, len; - sprintf(buf, "%s:%s", cfg.proxy_username, cfg.proxy_password); + sprintf(buf, "%s:%s", p->cfg.proxy_username, p->cfg.proxy_password); len = strlen(buf); - sprintf(buf2, "Proxy-Authorization: basic "); + sprintf(buf2, "Proxy-Authorization: Basic "); for (i = 0, j = strlen(buf2); i < len; i += 3, j += 4) - base64_encode_atom(buf+i, (len-i > 3 ? 3 : len-i), buf2+j); + base64_encode_atom((unsigned char *)(buf+i), + (len-i > 3 ? 3 : len-i), buf2+j); strcpy(buf2+j, "\r\n"); sk_write(p->sub_socket, buf2, strlen(buf2)); } - sprintf(buf, "\r\n"); - sk_write(p->sub_socket, buf, strlen(buf)); + sk_write(p->sub_socket, "\r\n", 2); p->state = 1; return 0; @@ -484,7 +569,7 @@ int proxy_http_negotiate (Proxy_Socket p, int change) * we'll need to parse, process, and respond to appropriately. */ - void *data; + char *data, *datap; int len; int eol; @@ -493,27 +578,45 @@ int proxy_http_negotiate (Proxy_Socket p, int change) int min_ver, maj_ver, status; /* get the status line */ - bufchain_prefix(&p->pending_input_data, &data, &len); + len = bufchain_size(&p->pending_input_data); + assert(len > 0); /* or we wouldn't be here */ + data = snewn(len, char); + bufchain_fetch(&p->pending_input_data, data, len); + eol = get_line_end(data, len); - if (eol < 0) return 1; + if (eol < 0) { + sfree(data); + return 1; + } - sscanf((char *)data, "HTTP/%i.%i %i", &maj_ver, &min_ver, &status); + status = -1; + /* We can't rely on whether the %n incremented the sscanf return */ + if (sscanf((char *)data, "HTTP/%i.%i %n", + &maj_ver, &min_ver, &status) < 2 || status == -1) { + plug_closing(p->plug, "Proxy error: HTTP response was absent", + PROXY_ERROR_GENERAL, 0); + sfree(data); + return 1; + } /* remove the status line from the input buffer. */ bufchain_consume(&p->pending_input_data, eol); - - /* TODO: we need to support Proxy-Auth headers */ - - if (status < 200 || status > 299) { + if (data[status] != '2') { /* error */ - /* TODO: return a more specific error message, - * TODO: based on the status code. - */ - plug_closing(p->plug, "Network error: Error while communicating with proxy", - PROXY_ERROR_GENERAL, 0); + char *buf; + data[eol] = '\0'; + while (eol > status && + (data[eol-1] == '\r' || data[eol-1] == '\n')) + data[--eol] = '\0'; + buf = dupprintf("Proxy error: %s", data+status); + plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0); + sfree(buf); + sfree(data); return 1; } + sfree(data); + p->state = 2; } @@ -523,16 +626,23 @@ int proxy_http_negotiate (Proxy_Socket p, int change) * header of length 2, (ie. just "\r\n") */ - bufchain_prefix(&p->pending_input_data, &data, &len); - eol = get_line_end(data, len); + len = bufchain_size(&p->pending_input_data); + assert(len > 0); /* or we wouldn't be here */ + data = snewn(len, char); + datap = data; + bufchain_fetch(&p->pending_input_data, data, len); + + eol = get_line_end(datap, len); + if (eol < 0) { + sfree(data); + return 1; + } while (eol > 2) { - /* TODO: Proxy-Auth stuff. in some cases, we will - * TODO: need to extract information from headers. - */ bufchain_consume(&p->pending_input_data, eol); - bufchain_prefix(&p->pending_input_data, &data, &len); - eol = get_line_end(data, len); + datap += eol; + len -= eol; + eol = get_line_end(datap, len); } if (eol == 2) { @@ -541,14 +651,16 @@ int proxy_http_negotiate (Proxy_Socket p, int change) proxy_activate(p); /* proxy activate will have dealt with * whatever is left of the buffer */ + sfree(data); return 1; } + sfree(data); return 1; } } - plug_closing(p->plug, "Network error: Unexpected proxy error", + plug_closing(p->plug, "Proxy error: unexpected proxy error", PROXY_ERROR_UNEXPECTED, 0); return 1; } @@ -572,18 +684,28 @@ int proxy_socks4_negotiate (Proxy_Socket p, int change) * user ID (variable length, null terminated string) */ - int length; - char * command; + int length, type, namelen; + char *command, addr[4], hostname[512]; - if (sk_addrtype(p->remote_addr) != AF_INET) { - plug_closing(p->plug, "Network error: SOCKS version 4 does not support IPv6", - PROXY_ERROR_GENERAL, 0); + type = sk_addrtype(p->remote_addr); + if (type == ADDRTYPE_IPV6) { + plug_closing(p->plug, "Proxy error: SOCKS version 4 does" + " not support IPv6", PROXY_ERROR_GENERAL, 0); return 1; + } else if (type == ADDRTYPE_IPV4) { + namelen = 0; + sk_addrcopy(p->remote_addr, addr); + } else { /* type == ADDRTYPE_NAME */ + assert(type == ADDRTYPE_NAME); + sk_getaddr(p->remote_addr, hostname, lenof(hostname)); + namelen = strlen(hostname) + 1; /* include the NUL */ + addr[0] = addr[1] = addr[2] = 0; + addr[3] = 1; } - length = strlen(cfg.proxy_username) + 9; - command = (char*) malloc(length); - strcpy(command + 8, cfg.proxy_username); + length = strlen(p->cfg.proxy_username) + namelen + 9; + command = snewn(length, char); + strcpy(command + 8, p->cfg.proxy_username); command[0] = 4; /* version 4 */ command[1] = 1; /* CONNECT command */ @@ -593,10 +715,14 @@ int proxy_socks4_negotiate (Proxy_Socket p, int change) command[3] = (char) p->remote_port & 0xff; /* address */ - sk_addrcopy(p->remote_addr, command + 4); + memcpy(command + 4, addr, 4); + + /* hostname */ + memcpy(command + 8 + strlen(p->cfg.proxy_username) + 1, + hostname, namelen); sk_write(p->sub_socket, command, length); - free(command); + sfree(command); p->state = 1; return 0; @@ -650,14 +776,16 @@ int proxy_socks4_negotiate (Proxy_Socket p, int change) * dest. address (4 bytes) */ - char *data; - int len; + char data[8]; + if (bufchain_size(&p->pending_input_data) < 8) + return 1; /* not got anything yet */ + /* get the response */ - bufchain_prefix(&p->pending_input_data, &data, &len); + bufchain_fetch(&p->pending_input_data, data, 8); if (data[0] != 0) { - plug_closing(p->plug, "Network error: SOCKS proxy responded with " + plug_closing(p->plug, "Proxy error: SOCKS proxy responded with " "unexpected reply code version", PROXY_ERROR_GENERAL, 0); return 1; @@ -667,22 +795,23 @@ int proxy_socks4_negotiate (Proxy_Socket p, int change) switch (data[1]) { case 92: - plug_closing(p->plug, "Network error: SOCKS server wanted IDENTD on client", + plug_closing(p->plug, "Proxy error: SOCKS server wanted IDENTD on client", PROXY_ERROR_GENERAL, 0); break; case 93: - plug_closing(p->plug, "Network error: Username and IDENTD on client don't agree", + plug_closing(p->plug, "Proxy error: Username and IDENTD on client don't agree", PROXY_ERROR_GENERAL, 0); break; case 91: default: - plug_closing(p->plug, "Network error: Error while communicating with proxy", + plug_closing(p->plug, "Proxy error: Error while communicating with proxy", PROXY_ERROR_GENERAL, 0); break; } return 1; } + bufchain_consume(&p->pending_input_data, 8); /* we're done */ proxy_activate(p); @@ -692,7 +821,7 @@ int proxy_socks4_negotiate (Proxy_Socket p, int change) } } - plug_closing(p->plug, "Network error: Unexpected proxy error", + plug_closing(p->plug, "Proxy error: unexpected proxy error", PROXY_ERROR_UNEXPECTED, 0); return 1; } @@ -713,13 +842,22 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) * 0x03 = CHAP */ - char command[3]; + char command[4]; + int len; command[0] = 5; /* version 5 */ - command[1] = 1; /* TODO: we don't currently support any auth methods */ - command[2] = 0x00; /* no authentication */ + if (p->cfg.proxy_username[0] || p->cfg.proxy_password[0]) { + command[1] = 2; /* two methods supported: */ + command[2] = 0x00; /* no authentication */ + command[3] = 0x02; /* username/password */ + len = 4; + } else { + command[1] = 1; /* one methods supported: */ + command[2] = 0x00; /* no authentication */ + len = 3; + } - sk_write(p->sub_socket, command, 3); + sk_write(p->sub_socket, command, len); p->state = 1; return 0; @@ -760,9 +898,6 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) * we'll need to parse, process, and respond to appropriately. */ - char *data; - int len; - if (p->state == 1) { /* initial response: @@ -775,12 +910,16 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) * 0x03 = CHAP * 0xff = no acceptable methods */ + char data[2]; + + if (bufchain_size(&p->pending_input_data) < 2) + return 1; /* not got anything yet */ /* get the response */ - bufchain_prefix(&p->pending_input_data, &data, &len); + bufchain_fetch(&p->pending_input_data, data, 2); if (data[0] != 5) { - plug_closing(p->plug, "Network error: Error while communicating with proxy", + plug_closing(p->plug, "Proxy error: SOCKS proxy returned unexpected version", PROXY_ERROR_GENERAL, 0); return 1; } @@ -790,11 +929,46 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) else if (data[1] == 0x02) p->state = 5; /* username/password authentication */ else if (data[1] == 0x03) p->state = 6; /* CHAP authentication */ else { - plug_closing(p->plug, "Network error: We don't support any of the SOCKS " - "server's authentication methods", + plug_closing(p->plug, "Proxy error: SOCKS proxy did not accept our authentication", PROXY_ERROR_GENERAL, 0); return 1; } + bufchain_consume(&p->pending_input_data, 2); + } + + if (p->state == 7) { + + /* password authentication reply format: + * version number (1 bytes) = 1 + * reply code (1 byte) + * 0 = succeeded + * >0 = failed + */ + char data[2]; + + if (bufchain_size(&p->pending_input_data) < 2) + return 1; /* not got anything yet */ + + /* get the response */ + bufchain_fetch(&p->pending_input_data, data, 2); + + if (data[0] != 1) { + plug_closing(p->plug, "Proxy error: SOCKS password " + "subnegotiation contained wrong version number", + PROXY_ERROR_GENERAL, 0); + return 1; + } + + if (data[1] != 0) { + + plug_closing(p->plug, "Proxy error: SOCKS proxy refused" + " password authentication", + PROXY_ERROR_GENERAL, 0); + return 1; + } + + bufchain_consume(&p->pending_input_data, 2); + p->state = 2; /* now proceed as authenticated */ } if (p->state == 2) { @@ -814,24 +988,31 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) * dest. port (2 bytes) [network order] */ - char command[22]; + char command[512]; int len; + int type; - if (sk_addrtype(p->remote_addr) == AF_INET) { - len = 10; + type = sk_addrtype(p->remote_addr); + if (type == ADDRTYPE_IPV4) { + len = 10; /* 4 hdr + 4 addr + 2 trailer */ command[3] = 1; /* IPv4 */ - } else { - len = 22; + sk_addrcopy(p->remote_addr, command+4); + } else if (type == ADDRTYPE_IPV6) { + len = 22; /* 4 hdr + 16 addr + 2 trailer */ command[3] = 4; /* IPv6 */ + sk_addrcopy(p->remote_addr, command+4); + } else { + assert(type == ADDRTYPE_NAME); + command[3] = 3; + sk_getaddr(p->remote_addr, command+5, 256); + command[4] = strlen(command+5); + len = 7 + command[4]; /* 4 hdr, 1 len, N addr, 2 trailer */ } command[0] = 5; /* version 5 */ command[1] = 1; /* CONNECT command */ command[2] = 0x00; - /* address */ - sk_addrcopy(p->remote_addr, command+4); - /* port */ command[len-2] = (char) (p->remote_port >> 8) & 0xff; command[len-1] = (char) p->remote_port & 0xff; @@ -864,67 +1045,109 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) * server bound address (variable) * server bound port (2 bytes) [network order] */ + char data[5]; + int len; + + /* First 5 bytes of packet are enough to tell its length. */ + if (bufchain_size(&p->pending_input_data) < 5) + return 1; /* not got anything yet */ /* get the response */ - bufchain_prefix(&p->pending_input_data, &data, &len); + bufchain_fetch(&p->pending_input_data, data, 5); if (data[0] != 5) { - plug_closing(p->plug, "Network error: Error while communicating with proxy", + plug_closing(p->plug, "Proxy error: SOCKS proxy returned wrong version number", PROXY_ERROR_GENERAL, 0); return 1; } if (data[1] != 0) { + char buf[256]; + + strcpy(buf, "Proxy error: "); switch (data[1]) { - case 1: - case 2: - case 3: - case 4: - case 5: - case 6: - case 7: - case 8: - default: - plug_closing(p->plug, "Network error: Error while communicating with proxy", - PROXY_ERROR_GENERAL, 0); + case 1: strcat(buf, "General SOCKS server failure"); break; + case 2: strcat(buf, "Connection not allowed by ruleset"); break; + case 3: strcat(buf, "Network unreachable"); break; + case 4: strcat(buf, "Host unreachable"); break; + case 5: strcat(buf, "Connection refused"); break; + case 6: strcat(buf, "TTL expired"); break; + case 7: strcat(buf, "Command not supported"); break; + case 8: strcat(buf, "Address type not supported"); break; + default: sprintf(buf+strlen(buf), + "Unrecognised SOCKS error code %d", + data[1]); break; } + plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0); + + return 1; + } + /* + * Eat the rest of the reply packet. + */ + len = 6; /* first 4 bytes, last 2 */ + switch (data[3]) { + case 1: len += 4; break; /* IPv4 address */ + case 4: len += 16; break;/* IPv6 address */ + case 3: len += (unsigned char)data[4]; break; /* domain name */ + default: + plug_closing(p->plug, "Proxy error: SOCKS proxy returned " + "unrecognised address format", + PROXY_ERROR_GENERAL, 0); return 1; } + if (bufchain_size(&p->pending_input_data) < len) + return 1; /* not got whole reply yet */ + bufchain_consume(&p->pending_input_data, len); /* we're done */ proxy_activate(p); - /* proxy activate will have dealt with - * whatever is left of the buffer */ return 1; } if (p->state == 4) { /* TODO: Handle GSSAPI authentication */ - plug_closing(p->plug, "Network error: We don't support GSSAPI authentication", + plug_closing(p->plug, "Proxy error: We don't support GSSAPI authentication", PROXY_ERROR_GENERAL, 0); return 1; } if (p->state == 5) { - /* TODO: Handle username/password authentication */ - plug_closing(p->plug, "Network error: We don't support username/password " - "authentication", + if (p->cfg.proxy_username[0] || p->cfg.proxy_password[0]) { + char userpwbuf[514]; + int ulen, plen; + ulen = strlen(p->cfg.proxy_username); + if (ulen > 255) ulen = 255; if (ulen < 1) ulen = 1; + plen = strlen(p->cfg.proxy_password); + if (plen > 255) plen = 255; if (plen < 1) plen = 1; + userpwbuf[0] = 1; /* version number of subnegotiation */ + userpwbuf[1] = ulen; + memcpy(userpwbuf+2, p->cfg.proxy_username, ulen); + userpwbuf[ulen+2] = plen; + memcpy(userpwbuf+ulen+3, p->cfg.proxy_password, plen); + sk_write(p->sub_socket, userpwbuf, ulen + plen + 3); + p->state = 7; + } else + plug_closing(p->plug, "Proxy error: Server chose " + "username/password authentication but we " + "didn't offer it!", PROXY_ERROR_GENERAL, 0); return 1; } if (p->state == 6) { /* TODO: Handle CHAP authentication */ - plug_closing(p->plug, "Network error: We don't support CHAP authentication", + plug_closing(p->plug, "Proxy error: We don't support CHAP authentication", PROXY_ERROR_GENERAL, 0); return 1; } + } - plug_closing(p->plug, "Network error: Unexpected proxy error", + plug_closing(p->plug, "Proxy error: Unexpected proxy error", PROXY_ERROR_UNEXPECTED, 0); return 1; } @@ -945,40 +1168,40 @@ int proxy_telnet_negotiate (Proxy_Socket p, int change) int so = 0, eo = 0; /* we need to escape \\, \%, \r, \n, \t, \x??, \0???, - * %%, %host, and %port + * %%, %host, %port, %user, and %pass */ - while (cfg.proxy_telnet_command[eo] != 0) { + while (p->cfg.proxy_telnet_command[eo] != 0) { /* scan forward until we hit end-of-line, * or an escape character (\ or %) */ - while (cfg.proxy_telnet_command[eo] != 0 && - cfg.proxy_telnet_command[eo] != '%' && - cfg.proxy_telnet_command[eo] != '\\') eo++; + while (p->cfg.proxy_telnet_command[eo] != 0 && + p->cfg.proxy_telnet_command[eo] != '%' && + p->cfg.proxy_telnet_command[eo] != '\\') eo++; /* if we hit eol, break out of our escaping loop */ - if (cfg.proxy_telnet_command[eo] == 0) break; + if (p->cfg.proxy_telnet_command[eo] == 0) break; /* if there was any unescaped text before the escape * character, send that now */ if (eo != so) { sk_write(p->sub_socket, - cfg.proxy_telnet_command + so, eo - so); + p->cfg.proxy_telnet_command + so, eo - so); } so = eo++; /* if the escape character was the last character of * the line, we'll just stop and send it. */ - if (cfg.proxy_telnet_command[eo] == 0) break; + if (p->cfg.proxy_telnet_command[eo] == 0) break; - if (cfg.proxy_telnet_command[so] == '\\') { + if (p->cfg.proxy_telnet_command[so] == '\\') { /* we recognize \\, \%, \r, \n, \t, \x??. * anything else, we just send unescaped (including the \). */ - switch (cfg.proxy_telnet_command[eo]) { + switch (p->cfg.proxy_telnet_command[eo]) { case '\\': sk_write(p->sub_socket, "\\", 1); @@ -1014,15 +1237,15 @@ int proxy_telnet_negotiate (Proxy_Socket p, int change) for (;;) { eo++; - if (cfg.proxy_telnet_command[eo] >= '0' && - cfg.proxy_telnet_command[eo] <= '9') - v += cfg.proxy_telnet_command[eo] - '0'; - else if (cfg.proxy_telnet_command[eo] >= 'a' && - cfg.proxy_telnet_command[eo] <= 'f') - v += cfg.proxy_telnet_command[eo] - 'a' + 10; - else if (cfg.proxy_telnet_command[eo] >= 'A' && - cfg.proxy_telnet_command[eo] <= 'F') - v += cfg.proxy_telnet_command[eo] - 'A' + 10; + if (p->cfg.proxy_telnet_command[eo] >= '0' && + p->cfg.proxy_telnet_command[eo] <= '9') + v += p->cfg.proxy_telnet_command[eo] - '0'; + else if (p->cfg.proxy_telnet_command[eo] >= 'a' && + p->cfg.proxy_telnet_command[eo] <= 'f') + v += p->cfg.proxy_telnet_command[eo] - 'a' + 10; + else if (p->cfg.proxy_telnet_command[eo] >= 'A' && + p->cfg.proxy_telnet_command[eo] <= 'F') + v += p->cfg.proxy_telnet_command[eo] - 'A' + 10; else { /* non hex character, so we abort and just * send the whole thing unescaped (including \x) @@ -1034,7 +1257,7 @@ int proxy_telnet_negotiate (Proxy_Socket p, int change) /* we only extract two hex characters */ if (i == 1) { - sk_write(p->sub_socket, &v, 1); + sk_write(p->sub_socket, (char *)&v, 1); eo++; break; } @@ -1047,33 +1270,46 @@ int proxy_telnet_negotiate (Proxy_Socket p, int change) default: sk_write(p->sub_socket, - cfg.proxy_telnet_command + so, 2); + p->cfg.proxy_telnet_command + so, 2); eo++; break; } } else { - /* % escape. we recognize %%, %host, %port. anything else, - * we just send unescaped (including the %). */ + /* % escape. we recognize %%, %host, %port, %user, %pass. + * anything else, we just send unescaped (including the %). + */ - if (cfg.proxy_telnet_command[eo] == '%') { + if (p->cfg.proxy_telnet_command[eo] == '%') { sk_write(p->sub_socket, "%", 1); eo++; - } - else if (strnicmp(cfg.proxy_telnet_command + eo, + } + else if (strnicmp(p->cfg.proxy_telnet_command + eo, "host", 4) == 0) { - char dest[64]; - sk_getaddr(p->remote_addr, dest, 64); + char dest[512]; + sk_getaddr(p->remote_addr, dest, lenof(dest)); sk_write(p->sub_socket, dest, strlen(dest)); eo += 4; - } - else if (strnicmp(cfg.proxy_telnet_command + eo, + } + else if (strnicmp(p->cfg.proxy_telnet_command + eo, "port", 4) == 0) { char port[8]; sprintf(port, "%i", p->remote_port); sk_write(p->sub_socket, port, strlen(port)); eo += 4; - } + } + else if (strnicmp(p->cfg.proxy_telnet_command + eo, + "user", 4) == 0) { + sk_write(p->sub_socket, p->cfg.proxy_username, + strlen(p->cfg.proxy_username)); + eo += 4; + } + else if (strnicmp(p->cfg.proxy_telnet_command + eo, + "pass", 4) == 0) { + sk_write(p->sub_socket, p->cfg.proxy_password, + strlen(p->cfg.proxy_password)); + eo += 4; + } else { /* we don't escape this, so send the % now, and * don't advance eo, so that we'll consider the @@ -1089,7 +1325,7 @@ int proxy_telnet_negotiate (Proxy_Socket p, int change) /* if there is any unescaped text at the end of the line, send it */ if (eo != so) { - sk_write(p->sub_socket, cfg.proxy_telnet_command + so, eo - so); + sk_write(p->sub_socket, p->cfg.proxy_telnet_command + so, eo - so); } p->state = 1; @@ -1138,7 +1374,7 @@ int proxy_telnet_negotiate (Proxy_Socket p, int change) return 1; } - plug_closing(p->plug, "Network error: Unexpected proxy error", + plug_closing(p->plug, "Proxy error: Unexpected proxy error", PROXY_ERROR_UNEXPECTED, 0); return 1; }