Delay sending the real ID request until after a proxy request is granted.
[tinc] / src / protocol_auth.c
index a7a6fe0..46b38eb 100644 (file)
@@ -1,7 +1,7 @@
 /*
     protocol_auth.c -- handle the meta-protocol, authentication
     Copyright (C) 1999-2005 Ivo Timmermans,
-                  2000-2013 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2016 Guus Sliepen <guus@tinc-vpn.org>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
 #include "netutl.h"
 #include "node.h"
 #include "protocol.h"
+#include "proxy.h"
 #include "utils.h"
 #include "xalloc.h"
 
-static bool send_proxyrequest(connection_t *c) {
-       switch(proxytype) {
-               case PROXY_HTTP: {
-                       char *host;
-                       char *port;
-
-                       sockaddr2str(&c->address, &host, &port);
-                       send_request(c, "CONNECT %s:%s HTTP/1.1\r\n\r", host, port);
-                       free(host);
-                       free(port);
-                       return true;
-               }
-               case PROXY_SOCKS4: {
-                       if(c->address.sa.sa_family != AF_INET) {
-                               logger(LOG_ERR, "Cannot connect to an IPv6 host through a SOCKS 4 proxy!");
-                               return false;
-                       }
-                       char s4req[9 + (proxyuser ? strlen(proxyuser) : 0)];
-                       s4req[0] = 4;
-                       s4req[1] = 1;
-                       memcpy(s4req + 2, &c->address.in.sin_port, 2);
-                       memcpy(s4req + 4, &c->address.in.sin_addr, 4);
-                       if(proxyuser)
-                               strcpy(s4req + 8, proxyuser);
-                       s4req[sizeof s4req - 1] = 0;
-                       c->tcplen = 8;
-                       return send_meta(c, s4req, sizeof s4req);
-               }
-               case PROXY_SOCKS5: {
-                       int len = 3 + 6 + (c->address.sa.sa_family == AF_INET ? 4 : 16);
-                       c->tcplen = 2;
-                       if(proxypass)
-                               len += 3 + strlen(proxyuser) + strlen(proxypass);
-                       char s5req[len];
-                       int i = 0;
-                       s5req[i++] = 5;
-                       s5req[i++] = 1;
-                       if(proxypass) {
-                               s5req[i++] = 2;
-                               s5req[i++] = 1;
-                               s5req[i++] = strlen(proxyuser);
-                               strcpy(s5req + i, proxyuser);
-                               i += strlen(proxyuser);
-                               s5req[i++] = strlen(proxypass);
-                               strcpy(s5req + i, proxypass);
-                               i += strlen(proxypass);
-                               c->tcplen += 2;
-                       } else {
-                               s5req[i++] = 0;
-                       }
-                       s5req[i++] = 5;
-                       s5req[i++] = 1;
-                       s5req[i++] = 0;
-                       if(c->address.sa.sa_family == AF_INET) {
-                               s5req[i++] = 1;
-                               memcpy(s5req + i, &c->address.in.sin_addr, 4);
-                               i += 4;
-                               memcpy(s5req + i, &c->address.in.sin_port, 2);
-                               i += 2;
-                               c->tcplen += 10;
-                       } else if(c->address.sa.sa_family == AF_INET6) {
-                               s5req[i++] = 3;
-                               memcpy(s5req + i, &c->address.in6.sin6_addr, 16);
-                               i += 16;
-                               memcpy(s5req + i, &c->address.in6.sin6_port, 2);
-                               i += 2;
-                               c->tcplen += 22;
-                       } else {
-                               logger(LOG_ERR, "Address family %hx not supported for SOCKS 5 proxies!", c->address.sa.sa_family);
-                               return false;
-                       }
-                       if(i > len)
-                               abort();
-                       return send_meta(c, s5req, sizeof s5req);
-               }
-               case PROXY_SOCKS4A:
-                       logger(LOG_ERR, "Proxy type not implemented yet");
-                       return false;
-               case PROXY_EXEC:
-                       return true;
-               default:
-                       logger(LOG_ERR, "Unknown proxy type");
-                       return false;
-       }
-}
-
 bool send_id(connection_t *c) {
-       if(proxytype && c->outgoing)
-               if(!send_proxyrequest(c))
-                       return false;
+       if(proxytype && c->outgoing && !c->status.proxy_passed)
+               return send_proxyrequest(c);
 
        return send_request(c, "%d %s %d", ID, myself->connection->name,
                                                myself->connection->protocol_version);
@@ -210,12 +124,20 @@ bool send_metakey(connection_t *c) {
        
        c->outkey = xrealloc(c->outkey, len);
 
-       if(!c->outctx)
-               c->outctx = xmalloc_and_zero(sizeof(*c->outctx));
+       if(!c->outctx) {
+               c->outctx = EVP_CIPHER_CTX_new();
+               if(!c->outctx)
+                       abort();
+       }
 
        /* Copy random data to the buffer */
 
-       RAND_pseudo_bytes((unsigned char *)c->outkey, len);
+       if (1 != RAND_bytes((unsigned char *)c->outkey, len)) {
+               int err = ERR_get_error();
+               logger(LOG_ERR, "Failed to generate meta key (%s)", ERR_error_string(err, NULL));
+               return false;
+       }
+
 
        /* The message we send must be smaller than the modulus of the RSA key.
           By definition, for a key of k bits, the following formula holds:
@@ -257,17 +179,17 @@ bool send_metakey(connection_t *c) {
        /* Send the meta key */
 
        x = send_request(c, "%d %d %d %d %d %s", METAKEY,
-                                        c->outcipher ? c->outcipher->nid : 0,
-                                        c->outdigest ? c->outdigest->type : 0, c->outmaclength,
+                                        c->outcipher ? EVP_CIPHER_nid(c->outcipher) : 0,
+                                        c->outdigest ? EVP_MD_type(c->outdigest) : 0, c->outmaclength,
                                         c->outcompression, buffer);
 
        /* Further outgoing requests are encrypted with the key we just generated */
 
        if(c->outcipher) {
                if(!EVP_EncryptInit(c->outctx, c->outcipher,
-                                       (unsigned char *)c->outkey + len - c->outcipher->key_len,
-                                       (unsigned char *)c->outkey + len - c->outcipher->key_len -
-                                       c->outcipher->iv_len)) {
+                                       (unsigned char *)c->outkey + len - EVP_CIPHER_key_length(c->outcipher),
+                                       (unsigned char *)c->outkey + len - EVP_CIPHER_key_length(c->outcipher) -
+                                       EVP_CIPHER_iv_length(c->outcipher))) {
                        logger(LOG_ERR, "Error during initialisation of cipher for %s (%s): %s",
                                        c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
                        return false;
@@ -303,8 +225,11 @@ bool metakey_h(connection_t *c) {
 
        c->inkey = xrealloc(c->inkey, len);
 
-       if(!c->inctx)
-               c->inctx = xmalloc_and_zero(sizeof(*c->inctx));
+       if(!c->inctx) {
+               c->inctx = EVP_CIPHER_CTX_new();
+               if(!c->inctx)
+                       abort();
+       }
 
        /* Convert the challenge from hexadecimal back to binary */
 
@@ -340,9 +265,9 @@ bool metakey_h(connection_t *c) {
                }
 
                if(!EVP_DecryptInit(c->inctx, c->incipher,
-                                       (unsigned char *)c->inkey + len - c->incipher->key_len,
-                                       (unsigned char *)c->inkey + len - c->incipher->key_len -
-                                       c->incipher->iv_len)) {
+                                       (unsigned char *)c->inkey + len - EVP_CIPHER_key_length(c->incipher),
+                                       (unsigned char *)c->inkey + len - EVP_CIPHER_key_length(c->incipher) -
+                                       EVP_CIPHER_iv_length(c->incipher))) {
                        logger(LOG_ERR, "Error during initialisation of cipher from %s (%s): %s",
                                        c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
                        return false;
@@ -363,7 +288,7 @@ bool metakey_h(connection_t *c) {
                        return false;
                }
 
-               if(c->inmaclength > c->indigest->md_size || c->inmaclength < 0) {
+               if(c->inmaclength > EVP_MD_size(c->indigest) || c->inmaclength < 0) {
                        logger(LOG_ERR, "%s (%s) uses bogus MAC length!", c->name, c->hostname);
                        return false;
                }
@@ -391,7 +316,11 @@ bool send_challenge(connection_t *c) {
 
        /* Copy random data to the buffer */
 
-       RAND_pseudo_bytes((unsigned char *)c->hischallenge, len);
+       if (1 != RAND_bytes((unsigned char *)c->hischallenge, len)) {
+               int err = ERR_get_error();
+               logger(LOG_ERR, "Failed to generate challenge (%s)", ERR_error_string(err, NULL));
+               return false; // Do not send predictable challenges, let connection attempt fail.
+       }
 
        /* Convert to hex */
 
@@ -443,22 +372,29 @@ bool challenge_h(connection_t *c) {
 
 bool send_chal_reply(connection_t *c) {
        char hash[EVP_MAX_MD_SIZE * 2 + 1];
-       EVP_MD_CTX ctx;
+       EVP_MD_CTX *ctx;
 
        /* Calculate the hash from the challenge we received */
 
-       if(!EVP_DigestInit(&ctx, c->indigest)
-                       || !EVP_DigestUpdate(&ctx, c->mychallenge, RSA_size(myself->connection->rsa_key))
-                       || !EVP_DigestFinal(&ctx, (unsigned char *)hash, NULL)) {
+       ctx = EVP_MD_CTX_create();
+       if(!ctx)
+               abort();
+
+       if(!EVP_DigestInit(ctx, c->indigest)
+                       || !EVP_DigestUpdate(ctx, c->mychallenge, RSA_size(myself->connection->rsa_key))
+                       || !EVP_DigestFinal(ctx, (unsigned char *)hash, NULL)) {
+               EVP_MD_CTX_destroy(ctx);
                logger(LOG_ERR, "Error during calculation of response for %s (%s): %s",
                        c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
                return false;
        }
 
+       EVP_MD_CTX_destroy(ctx);
+
        /* Convert the hash to a hexadecimal formatted string */
 
-       bin2hex(hash, hash, c->indigest->md_size);
-       hash[c->indigest->md_size * 2] = '\0';
+       bin2hex(hash, hash, EVP_MD_size(c->indigest));
+       hash[EVP_MD_size(c->indigest) * 2] = '\0';
 
        /* Send the reply */
 
@@ -468,7 +404,7 @@ bool send_chal_reply(connection_t *c) {
 bool chal_reply_h(connection_t *c) {
        char hishash[MAX_STRING_SIZE];
        char myhash[EVP_MAX_MD_SIZE];
-       EVP_MD_CTX ctx;
+       EVP_MD_CTX *ctx;
 
        if(sscanf(c->buffer, "%*d " MAX_STRING, hishash) != 1) {
                logger(LOG_ERR, "Got bad %s from %s (%s)", "CHAL_REPLY", c->name,
@@ -478,7 +414,7 @@ bool chal_reply_h(connection_t *c) {
 
        /* Check if the length of the hash is all right */
 
-       if(strlen(hishash) != c->outdigest->md_size * 2) {
+       if(strlen(hishash) != EVP_MD_size(c->outdigest) * 2) {
                logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name,
                           c->hostname, "wrong challenge reply length");
                return false;
@@ -486,24 +422,31 @@ bool chal_reply_h(connection_t *c) {
 
        /* Convert the hash to binary format */
 
-       if(!hex2bin(hishash, hishash, c->outdigest->md_size)) {
+       if(!hex2bin(hishash, hishash, EVP_MD_size(c->outdigest))) {
                logger(LOG_ERR, "Got bad %s from %s(%s): %s", "CHAL_REPLY", c->name, c->hostname, "invalid hash");
                return false;
        }
 
        /* Calculate the hash from the challenge we sent */
 
-       if(!EVP_DigestInit(&ctx, c->outdigest)
-                       || !EVP_DigestUpdate(&ctx, c->hischallenge, RSA_size(c->rsa_key))
-                       || !EVP_DigestFinal(&ctx, (unsigned char *)myhash, NULL)) {
+       ctx = EVP_MD_CTX_create();
+       if(!ctx)
+               abort();
+
+       if(!EVP_DigestInit(ctx, c->outdigest)
+                       || !EVP_DigestUpdate(ctx, c->hischallenge, RSA_size(c->rsa_key))
+                       || !EVP_DigestFinal(ctx, (unsigned char *)myhash, NULL)) {
+               EVP_MD_CTX_destroy(ctx);
                logger(LOG_ERR, "Error during calculation of response from %s (%s): %s",
                        c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
                return false;
        }
 
+       EVP_MD_CTX_destroy(ctx);
+
        /* Verify the incoming hash with the calculated hash */
 
-       if(memcmp(hishash, myhash, c->outdigest->md_size)) {
+       if(memcmp(hishash, myhash, EVP_MD_size(c->outdigest))) {
                logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name,
                           c->hostname, "wrong challenge reply");
 
@@ -592,7 +535,6 @@ static void send_everything(connection_t *c) {
 
 bool ack_h(connection_t *c) {
        char hisport[MAX_STRING_SIZE];
-       char *hisaddress;
        int weight, mtu;
        uint32_t options;
        node_t *n;
@@ -661,9 +603,8 @@ bool ack_h(connection_t *c) {
        c->edge = new_edge();
        c->edge->from = myself;
        c->edge->to = n;
-       sockaddr2str(&c->address, &hisaddress, NULL);
-       c->edge->address = str2sockaddr(hisaddress, hisport);
-       free(hisaddress);
+       sockaddrcpy(&c->edge->address, &c->address);
+       sockaddr_setport(&c->edge->address, hisport);
        c->edge->weight = (weight + c->estimated_weight) / 2;
        c->edge->connection = c;
        c->edge->options = c->options;