Wipe (some) secrets from memory after use

[tinc] / src / invitation.c

diff --git a/src/invitation.c b/src/invitation.c
index cff9e72..5db1e98 100644 (file)
--- a/src/invitation.c
+++ b/src/invitation.c
@@ -314,6 +314,7 @@ static bool copy_config_replacing_port(FILE *out, const char *filename, const ch
                }
        }
 
+       memzero(line, sizeof(line));
        fclose(in);
        return true;
 }
@@ -521,6 +522,7 @@ int cmd_invite(int argc, char *argv[]) {
        int ifd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
 
        if(!ifd) {
+               memzero(cookie, sizeof(cookie));
                fprintf(stderr, "Could not create invitation file %s: %s\n", filename, strerror(errno));
                return 1;
        }
@@ -536,9 +538,17 @@ int cmd_invite(int argc, char *argv[]) {
        char *port = NULL;
 
        if(!get_my_hostname(&address, &port)) {
+               memzero(cookie, sizeof(cookie));
                return 1;
        }
 
+       // Create an URL from the local address, key hash and cookie
+       char *url;
+       xasprintf(&url, "%s/%s%s", address, hash, cookie);
+
+       memzero(cookie, sizeof(cookie));
+       free(address);
+
        // Fill in the details.
        fprintf(f, "Name = %s\n", argv[1]);
 
@@ -577,14 +587,10 @@ int cmd_invite(int argc, char *argv[]) {
 
        if(!appended) {
                fprintf(stderr, "Could not append my config to invitation file: %s.\n", strerror(errno));
-               free(address);
+               free_string(url);
                return 1;
        }
 
-       // Create an URL from the local address, key hash and cookie
-       char *url;
-       xasprintf(&url, "%s/%s%s", address, hash, cookie);
-
        // Call the inviation-created script
        environment_t env;
        environment_init(&env);
@@ -595,8 +601,7 @@ int cmd_invite(int argc, char *argv[]) {
        environment_exit(&env);
 
        puts(url);
-       free(url);
-       free(address);
+       free_string(url);
 
        return 0;
 }
@@ -972,9 +977,9 @@ make_names:
                return false;
        }
 
-       char *b64key = ecdsa_get_base64_public_key(key);
+       char *b64_pubkey = ecdsa_get_base64_public_key(key);
 
-       if(!b64key) {
+       if(!b64_pubkey) {
                return false;
        }
 
@@ -994,10 +999,10 @@ make_names:
 
        fclose(f);
 
-       fprintf(fh, "Ed25519PublicKey = %s\n", b64key);
+       fprintf(fh, "Ed25519PublicKey = %s\n", b64_pubkey);
 
-       sptps_send_record(&sptps, 1, b64key, strlen(b64key));
-       free(b64key);
+       sptps_send_record(&sptps, 1, b64_pubkey, strlen(b64_pubkey));
+       free(b64_pubkey);
        ecdsa_free(key);
 
 #ifndef DISABLE_LEGACY
@@ -1299,13 +1304,13 @@ int cmd_join(int argc, char *argv[]) {
                return 1;
        }
 
-       char *b64key = ecdsa_get_base64_public_key(key);
+       char *b64_pubkey = ecdsa_get_base64_public_key(key);
 
        // Connect to the tinc daemon mentioned in the URL.
        struct addrinfo *ai = str2addrinfo(address, port, SOCK_STREAM);
 
        if(!ai) {
-               free(b64key);
+               free(b64_pubkey);
                ecdsa_free(key);
                return 1;
        }
@@ -1320,7 +1325,7 @@ next:
 
                if(!aip) {
                        freeaddrinfo(ai);
-                       free(b64key);
+                       free(b64_pubkey);
                        ecdsa_free(key);
                        return 1;
                }
@@ -1346,13 +1351,13 @@ next:
        fprintf(stderr, "Connected to %s port %s...\n", address, port);
 
        // Tell him we have an invitation, and give him our throw-away key.
-       ssize_t len = snprintf(line, sizeof(line), "0 ?%s %d.%d\n", b64key, PROT_MAJOR, PROT_MINOR);
+       ssize_t len = snprintf(line, sizeof(line), "0 ?%s %d.%d\n", b64_pubkey, PROT_MAJOR, PROT_MINOR);
 
        if(len <= 0 || (size_t)len >= sizeof(line)) {
                abort();
        }
 
-       if(!sendline(sock, "0 ?%s %d.%d", b64key, PROT_MAJOR, 1)) {
+       if(!sendline(sock, "0 ?%s %d.%d", b64_pubkey, PROT_MAJOR, 1)) {
                fprintf(stderr, "Error sending request to %s port %s: %s\n", address, port, strerror(errno));
                closesocket(sock);
                goto next;
@@ -1371,8 +1376,8 @@ next:
        ai = NULL;
        aip = NULL;
 
-       free(b64key);
-       b64key = NULL;
+       free(b64_pubkey);
+       b64_pubkey = NULL;
 
        // Check if the hash of the key he gave us matches the hash in the URL.
        char *fingerprint = line + 2;