Prevent read_rsa_public_key() from returning an uninitialized RSA structure.

In case the config file could not be opened a new but unitialized RSA structure
would be returned, causing a segmentation fault later on. This would only
happen in the case that the config file could be opened before, but not when
read_rsa_public_key() was called. This situation could occur when the --user
option was used, and the config files were not readable by the specified user.

diff --git a/src/net_setup.c b/src/net_setup.c
index f18e3bf..c4337cc 100644 (file)
--- a/src/net_setup.c
+++ b/src/net_setup.c
@@ -113,11 +113,14 @@ bool read_rsa_public_key(connection_t *c) {
        xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
        fp = fopen(fname, "r");
 
-       if(fp) {
-               c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
-               fclose(fp);
+       if(!fp) {
+               logger(LOG_ERR, "Error reading RSA public key file `%s': %s", fname, strerror(errno));
+               free(fname);
+               return;
        }
 
+       c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
+       fclose(fp);
        free(fname);
 
        if(c->rsa_key)
@@ -128,12 +131,15 @@ bool read_rsa_public_key(connection_t *c) {
        xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
        fp = fopen(fname, "r");
 
-       if(fp) {
-               c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
-//             RSA_blinding_on(c->rsa_key, NULL);
-               fclose(fp);
+       if(!fp) {
+               logger(LOG_ERR, "Error reading RSA public key file `%s': %s", fname, strerror(errno));
+               free(fname);
+               return;
        }
 
+       c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
+//     RSA_blinding_on(c->rsa_key, NULL);
+       fclose(fp);
        free(fname);
 
        if(c->rsa_key)