upstream: change explicit_bzero();free() to freezero()

While freezero() returns early if the pointer is NULL the tests for
NULL in callers are left to avoid warnings about passing an
uninitialised size argument across a function boundry.

ok deraadt@ djm@

OpenBSD-Commit-ID: 2660fa334fcc7cd05ec74dd99cb036f9ade6384a

1 files changed, 9 insertions, 17 deletions

diff --git a/ssh-keygen.c b/ssh-keygen.c
index 0d6ed1fff..d9c207b42 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.398 2020/02/07 03:27:54 djm Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.399 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -327,8 +327,7 @@ load_identity(const char *filename, char **commentp)
         else
                 pass = read_passphrase("Enter passphrase: ", RP_ALLOW_STDIN);
         r = sshkey_load_private(filename, pass, &prv, commentp);
-        explicit_bzero(pass, strlen(pass));
-        free(pass);
+        freezero(pass, strlen(pass));
         if (r != 0)
                 fatal("Load key \"%s\": %s", filename, ssh_err(r));
         return prv;
@@ -1424,8 +1423,7 @@ do_change_passphrase(struct passwd *pw)
                             RP_ALLOW_STDIN);
                 r = sshkey_load_private(identity_file, old_passphrase,
                     &private, &comment);
-                explicit_bzero(old_passphrase, strlen(old_passphrase));
-                free(old_passphrase);
+                freezero(old_passphrase, strlen(old_passphrase));
                 if (r != 0)
                         goto badkey;
         } else if (r != 0) {
@@ -1456,8 +1454,7 @@ do_change_passphrase(struct passwd *pw)
                         exit(1);
                 }
                 /* Destroy the other copy. */
-                explicit_bzero(passphrase2, strlen(passphrase2));
-                free(passphrase2);
+                freezero(passphrase2, strlen(passphrase2));
         }
 
         /* Save the file using the new passphrase. */
@@ -1465,15 +1462,13 @@ do_change_passphrase(struct passwd *pw)
             comment, private_key_format, openssh_format_cipher, rounds)) != 0) {
                 error("Saving key \"%s\" failed: %s.",
                     identity_file, ssh_err(r));
-                explicit_bzero(passphrase1, strlen(passphrase1));
-                free(passphrase1);
+                freezero(passphrase1, strlen(passphrase1));
                 sshkey_free(private);
                 free(comment);
                 exit(1);
         }
         /* Destroy the passphrase and the copy of the key in memory. */
-        explicit_bzero(passphrase1, strlen(passphrase1));
-        free(passphrase1);
+        freezero(passphrase1, strlen(passphrase1));
         sshkey_free(private);            /* Destroys contents */
         free(comment);
 
@@ -1543,8 +1538,7 @@ do_change_comment(struct passwd *pw, const char *identity_comment)
                 /* Try to load using the passphrase. */
                 if ((r = sshkey_load_private(identity_file, passphrase,
                     &private, &comment)) != 0) {
-                        explicit_bzero(passphrase, strlen(passphrase));
-                        free(passphrase);
+                        freezero(passphrase, strlen(passphrase));
                         fatal("Cannot load private key \"%s\": %s.",
                             identity_file, ssh_err(r));
                 }
@@ -1589,14 +1583,12 @@ do_change_comment(struct passwd *pw, const char *identity_comment)
             rounds)) != 0) {
                 error("Saving key \"%s\" failed: %s",
                     identity_file, ssh_err(r));
-                explicit_bzero(passphrase, strlen(passphrase));
-                free(passphrase);
+                freezero(passphrase, strlen(passphrase));
                 sshkey_free(private);
                 free(comment);
                 exit(1);
         }
-        explicit_bzero(passphrase, strlen(passphrase));
-        free(passphrase);
+        freezero(passphrase, strlen(passphrase));
         if ((r = sshkey_from_private(private, &public)) != 0)
                 fatal("sshkey_from_private failed: %s", ssh_err(r));
         sshkey_free(private);