cgtest: fix all memory leaks.

I've adjusted the cmdgen main program so that it does all early
returns via the 'goto out' idiom, so that they still go through all
the last-minute freeing steps. That meant I had to adjust a few of the
last-minute freeing steps so they don't try to do impossible things
like freeing SSH2_WRONG_PASSPHRASE or calling a vtable method of a
null object. Also added a couple of completely missing frees, in
cmdgen itself ('outfiletmp') and in the cgtest wrapper main ('fp').

Now cgtest gets a completely clean run through Leak Sanitiser.

1 files changed, 40 insertions, 27 deletions

diff --git a/cmdgen.c b/cmdgen.c
index 0ba70f19..60db95d3 100644
--- a/cmdgen.c
+++ b/cmdgen.c
@@ -236,6 +236,9 @@ int main(int argc, char **argv)
     bool load_encrypted;
     progfn_t progressfn = is_interactive() ? progress_update : no_progress;
     const char *random_device = NULL;
+    int exit_status = 0;
+
+    #define RETURN(status) do { exit_status = (status); goto out; } while (0)
 
     /* ------------------------------------------------------------------
      * Parse the command line to figure out what we've been asked to do.
@@ -247,7 +250,7 @@ int main(int argc, char **argv)
      */
     if (argc <= 1) {
         usage(true);
-        return 0;
+        RETURN(0);
     }
 
     /*
@@ -518,10 +521,10 @@ int main(int argc, char **argv)
     }
 
     if (errs)
-        return 1;
+        RETURN(1);
 
     if (nogo)
-        return 0;
+        RETURN(0);
 
     /*
      * If run with at least one argument _but_ not the required
@@ -529,7 +532,7 @@ int main(int argc, char **argv)
      */
     if (!infile && keytype == NOKEYGEN) {
         usage(true);
-        return 1;
+        RETURN(1);
     }
 
     /* ------------------------------------------------------------------
@@ -542,7 +545,7 @@ int main(int argc, char **argv)
      */
     if (keytype != NOKEYGEN && infile) {
         fprintf(stderr, "puttygen: cannot both load and generate a key\n");
-        return 1;
+        RETURN(1);
     }
 
     /*
@@ -553,7 +556,7 @@ int main(int argc, char **argv)
          outtype != OPENSSH_NEW && outtype != SSHCOM)) {
         fprintf(stderr, "puttygen: this would generate a new key but "
                 "discard the private part\n");
-        return 1;
+        RETURN(1);
     }
 
     /*
@@ -570,14 +573,14 @@ int main(int argc, char **argv)
           case SSH_KEYTYPE_UNKNOWN:
             fprintf(stderr, "puttygen: unable to load file `%s': %s\n",
                     infile, key_type_to_str(intype));
-            return 1;
+            RETURN(1);
 
           case SSH_KEYTYPE_SSH1:
           case SSH_KEYTYPE_SSH1_PUBLIC:
             if (sshver == 2) {
                 fprintf(stderr, "puttygen: conversion from SSH-1 to SSH-2 keys"
                         " not supported\n");
-                return 1;
+                RETURN(1);
             }
             sshver = 1;
             break;
@@ -591,7 +594,7 @@ int main(int argc, char **argv)
             if (sshver == 1) {
                 fprintf(stderr, "puttygen: conversion from SSH-2 to SSH-1 keys"
                         " not supported\n");
-                return 1;
+                RETURN(1);
             }
             sshver = 2;
             break;
@@ -625,7 +628,7 @@ int main(int argc, char **argv)
         if (!change_passphrase && !comment) {
             fprintf(stderr, "puttygen: this command would perform no useful"
                     " action\n");
-            return 1;
+            RETURN(1);
         }
     } else {
         if (!outfile) {
@@ -636,7 +639,7 @@ int main(int argc, char **argv)
             if (outtype == PRIVATE || outtype == OPENSSH_AUTO ||
                 outtype == OPENSSH_NEW || outtype == SSHCOM) {
                 fprintf(stderr, "puttygen: need to specify an output file\n");
-                return 1;
+                RETURN(1);
             }
         }
     }
@@ -661,7 +664,7 @@ int main(int argc, char **argv)
                            intype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH)) {
         fprintf(stderr, "puttygen: cannot perform this action on a "
                 "public-key-only input file\n");
-        return 1;
+        RETURN(1);
     }
 
     /* ------------------------------------------------------------------
@@ -694,7 +697,7 @@ int main(int argc, char **argv)
         if (!entropy) {
             fprintf(stderr, "puttygen: failed to collect entropy, "
                     "could not generate key\n");
-            return 1;
+            RETURN(1);
         }
         random_setup_special();
         random_reseed(make_ptrlen(entropy, bits / 8));
@@ -772,7 +775,7 @@ int main(int argc, char **argv)
                 if (!ret) {
                     free_prompts(p);
                     perror("puttygen: unable to read passphrase");
-                    return 1;
+                    RETURN(1);
                 } else {
                     old_passphrase = dupstr(p->prompts[0]->result);
                     free_prompts(p);
@@ -788,6 +791,7 @@ int main(int argc, char **argv)
           case SSH_KEYTYPE_SSH1:
           case SSH_KEYTYPE_SSH1_PUBLIC:
             ssh1key = snew(RSAKey);
+            memset(ssh1key, 0, sizeof(RSAKey));
             if (!load_encrypted) {
                 strbuf *blob;
                 BinarySource src[1];
@@ -871,7 +875,7 @@ int main(int argc, char **argv)
         if (error) {
             fprintf(stderr, "puttygen: error loading `%s': %s\n",
                     infile, error);
-            return 1;
+            RETURN(1);
         }
     }
 
@@ -915,12 +919,12 @@ int main(int argc, char **argv)
         if (!ret) {
             free_prompts(p);
             perror("puttygen: unable to read new passphrase");
-            return 1;
+            RETURN(1);
         } else {
             if (strcmp(p->prompts[0]->result, p->prompts[1]->result)) {
                 free_prompts(p);
                 fprintf(stderr, "puttygen: passphrases do not match\n");
-                return 1;
+                RETURN(1);
             }
             new_passphrase = dupstr(p->prompts[0]->result);
             free_prompts(p);
@@ -955,19 +959,19 @@ int main(int argc, char **argv)
             ret = rsa1_save_f(outfilename, ssh1key, new_passphrase);
             if (!ret) {
                 fprintf(stderr, "puttygen: unable to save SSH-1 private key\n");
-                return 1;
+                RETURN(1);
             }
         } else {
             assert(ssh2key);
             ret = ppk_save_f(outfilename, ssh2key, new_passphrase);
             if (!ret) {
                 fprintf(stderr, "puttygen: unable to save SSH-2 private key\n");
-                return 1;
+                RETURN(1);
             }
         }
         if (outfiletmp) {
             if (!move(outfiletmp, outfile))
-                return 1;              /* rename failed */
+                RETURN(1);              /* rename failed */
         }
         break;
 
@@ -1065,15 +1069,19 @@ int main(int argc, char **argv)
         ret = export_ssh2(outfilename, real_outtype, ssh2key, new_passphrase);
         if (!ret) {
             fprintf(stderr, "puttygen: unable to export key\n");
-            return 1;
+            RETURN(1);
         }
         if (outfiletmp) {
             if (!move(outfiletmp, outfile))
-                return 1;              /* rename failed */
+                RETURN(1);              /* rename failed */
         }
         break;
     }
 
+  out:
+
+    #undef RETURN
+
     if (old_passphrase) {
         smemclr(old_passphrase, strlen(old_passphrase));
         sfree(old_passphrase);
@@ -1087,9 +1095,10 @@ int main(int argc, char **argv)
         freersakey(ssh1key);
         sfree(ssh1key);
     }
-    if (ssh2key) {
+    if (ssh2key && ssh2key != SSH2_WRONG_PASSPHRASE) {
         sfree(ssh2key->comment);
-        ssh_key_free(ssh2key->key);
+        if (ssh2key->key)
+            ssh_key_free(ssh2key->key);
         sfree(ssh2key);
     }
     if (ssh2blob)
@@ -1097,9 +1106,11 @@ int main(int argc, char **argv)
     sfree(origcomment);
     if (infilename)
         filename_free(infilename);
-    filename_free(outfilename);
+    if (outfilename)
+        filename_free(outfilename);
+    sfree(outfiletmp);
 
-    return 0;
+    return exit_status;
 }
 
 #ifdef TEST_CMDGEN
@@ -1308,7 +1319,7 @@ int main(int argc, char **argv)
     for (i = 0; i < lenof(keytypes); i++) {
         char filename[128], osfilename[128], scfilename[128];
         char pubfilename[128], tmpfilename1[128], tmpfilename2[128];
-        char *fp;
+        char *fp = NULL;
 
         sprintf(filename, "test-%s.ppk", keytypes[i]);
         sprintf(pubfilename, "test-%s.pub", keytypes[i]);
@@ -1677,6 +1688,8 @@ int main(int argc, char **argv)
          */
         setup_passphrases(NULL);
         test(1, "puttygen", "-C", "spurious-new-comment", pubfilename, NULL);
+
+        sfree(fp);
     }
     printf("%d passes, %d fails\n", passes, fails);
     return fails == 0 ? 0 : 1;