tincctl: Avoid falling back to 1024 bits RSA key generation when an invalid key size...

[tinc] / src / tincctl.c

diff --git a/src/tincctl.c b/src/tincctl.c
index 4231cce..1f0246c 100644 (file)
--- a/src/tincctl.c
+++ b/src/tincctl.c
@@ -1,6 +1,6 @@
 /*
     tincctl.c -- Controlling a running tincd
-    Copyright (C) 2007-2015 Guus Sliepen <guus@tinc-vpn.org>
+    Copyright (C) 2007-2016 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
@@ -89,7 +89,7 @@ static struct option const long_options[] = {
 static void version(void) {
        printf("%s version %s (built %s %s, protocol %d.%d)\n", PACKAGE,
                   BUILD_VERSION, BUILD_DATE, BUILD_TIME, PROT_MAJOR, PROT_MINOR);
-       printf("Copyright (C) 1998-2015 Ivo Timmermans, Guus Sliepen and others.\n"
+       printf("Copyright (C) 1998-2016 Ivo Timmermans, Guus Sliepen and others.\n"
                        "See the AUTHORS file for a complete list.\n\n"
                        "tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
                        "and you are welcome to redistribute it under certain conditions;\n"
@@ -446,11 +446,13 @@ static bool rsa_keygen(int bits, bool ask) {
        // Make sure the key size is a multiple of 8 bits.
        bits &= ~0x7;
 
-       // Force them to be between 1024 and 8192 bits long.
-       if(bits < 1024)
-               bits = 1024;
-       if(bits > 8192)
-               bits = 8192;
+       // Make sure that a valid key size is used.
+       if(bits < 1024 || bits > 8192) {
+               fprintf(stderr, "Invalid key size %d specified! It should be between 1024 and 8192 bits.\n", bits);
+               return false;
+       } else if(bits < 2048) {
+               fprintf(stderr, "WARNING: generating a weak %d bits RSA key! 2048 or more bits are recommended.\n", bits);
+       }
 
        fprintf(stderr, "Generating %d bits keys:\n", bits);
 
@@ -560,6 +562,7 @@ bool sendline(int fd, char *format, ...) {
 
        va_start(ap, format);
        blen = vsnprintf(buffer, sizeof buffer, format, ap);
+       buffer[sizeof buffer - 1] = 0;
        va_end(ap);
 
        if(blen < 1 || blen >= sizeof buffer)
@@ -718,6 +721,13 @@ bool connect_tincd(bool verbose) {
        }
 
        fclose(f);
+       if ((pid == 0) || (kill(pid, 0) && (errno == ESRCH))) {
+               fprintf(stderr, "Could not find tincd running at pid %d\n", pid);
+               /* clean up the stale socket and pid file */
+               unlink(pidfilename);
+               unlink(unixsocketname);
+               return false;
+       }
 
 #ifndef HAVE_MINGW
        struct sockaddr_un sa;
@@ -878,7 +888,7 @@ static int cmd_start(int argc, char *argv[]) {
 
        if(!pid) {
                close(pfd[0]);
-               char buf[100] = "";
+               char buf[100];
                snprintf(buf, sizeof buf, "%d", pfd[1]);
                setenv("TINC_UMBILICAL", buf, true);
                exit(execvp(c, nargv));
@@ -1384,7 +1394,7 @@ static int cmd_pid(int argc, char *argv[]) {
                return 1;
        }
 
-       if(!connect_tincd(true) && !pid)
+       if(!connect_tincd(true) || !pid)
                return 1;
 
        printf("%d\n", pid);
@@ -1433,7 +1443,7 @@ char *get_my_name(bool verbose) {
        return NULL;
 }
 
-static ecdsa_t *get_pubkey(FILE *f) {
+ecdsa_t *get_pubkey(FILE *f) {
        char buf[4096];
        char *value;
        while(fgets(buf, sizeof buf, f)) {
@@ -2513,10 +2523,12 @@ static int cmd_verify(int argc, char *argv[]) {
        char *newline = memchr(data, '\n', len);
        if(!newline || (newline - data > MAX_STRING_SIZE - 1)) {
                fprintf(stderr, "Invalid input\n");
+               free(data);
                return 1;
        }
 
        *newline++ = '\0';
+       size_t skip = newline - data;
 
        char signer[MAX_STRING_SIZE] = "";
        char sig[MAX_STRING_SIZE] = "";
@@ -2524,11 +2536,13 @@ static int cmd_verify(int argc, char *argv[]) {
 
        if(sscanf(data, "Signature = %s %ld %s", signer, &t, sig) != 3 || strlen(sig) != 86 || !t || !check_id(signer)) {
                fprintf(stderr, "Invalid input\n");
+               free(data);
                return 1;
        }
 
        if(node && strcmp(node, signer)) {
                fprintf(stderr, "Signature is not made by %s\n", node);
+               free(data);
                return 1;
        }
 
@@ -2543,6 +2557,8 @@ static int cmd_verify(int argc, char *argv[]) {
        memcpy(data + len, trailer, trailer_len);
        free(trailer);
 
+       newline = data + skip;
+
        char fname[PATH_MAX];
        snprintf(fname, sizeof fname, "%s" SLASH "hosts" SLASH "%s", confbase, node);
        FILE *fp = fopen(fname, "r");
@@ -2820,8 +2836,10 @@ static int cmd_shell(int argc, char *argv[]) {
                if(nargc == argc)
                        continue;
 
-               if(!strcasecmp(nargv[argc], "exit") || !strcasecmp(nargv[argc], "quit"))
+               if(!strcasecmp(nargv[argc], "exit") || !strcasecmp(nargv[argc], "quit")) {
+                       free(nargv);
                        return result;
+               }
 
                bool found = false;