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

auth-options.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: auth-options.c,v 1.90 2019/11/25 00:54:23 djm Exp $ */
+/* $OpenBSD: auth-options.c,v 1.91 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright (c) 2018 Damien Miller <[email protected]>
  *
@@ -222,8 +222,7 @@ sshauthopt_free(struct sshauthopt *opts)
 		free(opts->permitlisten[i]);
 	free(opts->permitlisten);
 
-	explicit_bzero(opts, sizeof(*opts));
-	free(opts);
+	freezero(opts, sizeof(*opts));
 }
 
 struct sshauthopt *

auth2-chall.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-chall.c,v 1.52 2019/11/13 04:47:52 deraadt Exp $ */
+/* $OpenBSD: auth2-chall.c,v 1.53 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2001 Per Allansson.  All rights reserved.
@@ -147,8 +147,7 @@ kbdint_free(KbdintAuthctxt *kbdintctxt)
 	if (kbdintctxt->device)
 		kbdint_reset_device(kbdintctxt);
 	free(kbdintctxt->devices);
-	explicit_bzero(kbdintctxt, sizeof(*kbdintctxt));
-	free(kbdintctxt);
+	freezero(kbdintctxt, sizeof(*kbdintctxt));
 }
 /* get next device */
 static int

auth2-passwd.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-passwd.c,v 1.17 2019/09/06 04:53:27 djm Exp $ */
+/* $OpenBSD: auth2-passwd.c,v 1.18 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -66,8 +66,7 @@ userauth_passwd(struct ssh *ssh)
 		logit("password change not supported");
 	else if (PRIVSEP(auth_password(ssh, password)) == 1)
 		authenticated = 1;
-	explicit_bzero(password, len);
-	free(password);
+	freezero(password, len);
 	return authenticated;
 }
 

authfd.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: authfd.c,v 1.121 2019/12/21 02:19:13 djm Exp $ */
+/* $OpenBSD: authfd.c,v 1.122 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -561,10 +561,8 @@ ssh_remove_identity(int sock, struct sshkey *key)
 		goto out;
 	r = decode_reply(type);
  out:
-	if (blob != NULL) {
-		explicit_bzero(blob, blen);
-		free(blob);
-	}
+	if (blob != NULL)
+		freezero(blob, blen);
 	sshbuf_free(msg);
 	return r;
 }

channels.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.c,v 1.395 2020/01/25 06:40:20 djm Exp $ */
+/* $OpenBSD: channels.c,v 1.396 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -625,14 +625,12 @@ channel_free(struct ssh *ssh, Channel *c)
 		if (cc->abandon_cb != NULL)
 			cc->abandon_cb(ssh, c, cc->ctx);
 		TAILQ_REMOVE(&c->status_confirms, cc, entry);
-		explicit_bzero(cc, sizeof(*cc));
-		free(cc);
+		freezero(cc, sizeof(*cc));
 	}
 	if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
 		c->filter_cleanup(ssh, c->self, c->filter_ctx);
 	sc->channels[c->self] = NULL;
-	explicit_bzero(c, sizeof(*c));
-	free(c);
+	freezero(c, sizeof(*c));
 }
 
 void
@@ -3295,8 +3293,7 @@ channel_input_status_confirm(int type, u_int32_t seq, struct ssh *ssh)
 		return 0;
 	cc->cb(ssh, type, c, cc->ctx);
 	TAILQ_REMOVE(&c->status_confirms, cc, entry);
-	explicit_bzero(cc, sizeof(*cc));
-	free(cc);
+	freezero(cc, sizeof(*cc));
 	return 0;
 }
 

cipher.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cipher.c,v 1.114 2020/01/23 10:24:29 dtucker Exp $ */
+/* $OpenBSD: cipher.c,v 1.115 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -328,8 +328,7 @@ cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
 #ifdef WITH_OPENSSL
 			EVP_CIPHER_CTX_free(cc->evp);
 #endif /* WITH_OPENSSL */
-			explicit_bzero(cc, sizeof(*cc));
-			free(cc);
+			freezero(cc, sizeof(*cc));
 		}
 	}
 	return ret;
@@ -434,8 +433,7 @@ cipher_free(struct sshcipher_ctx *cc)
 	EVP_CIPHER_CTX_free(cc->evp);
 	cc->evp = NULL;
 #endif
-	explicit_bzero(cc, sizeof(*cc));
-	free(cc);
+	freezero(cc, sizeof(*cc));
 }
 
 /*

clientloop.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.341 2020/02/26 01:31:47 dtucker Exp $ */
+/* $OpenBSD: clientloop.c,v 1.342 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -473,8 +473,7 @@ client_global_request_reply(int type, u_int32_t seq, struct ssh *ssh)
 		gc->cb(ssh, type, seq, gc->ctx);
 	if (--gc->ref_count <= 0) {
 		TAILQ_REMOVE(&global_confirms, gc, entry);
-		explicit_bzero(gc, sizeof(*gc));
-		free(gc);
+		freezero(gc, sizeof(*gc));
 	}
 
 	ssh_packet_set_alive_timeouts(ssh, 0);

digest-libc.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: digest-libc.c,v 1.6 2017/05/08 22:57:38 djm Exp $ */
+/* $OpenBSD: digest-libc.c,v 1.7 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright (c) 2013 Damien Miller <[email protected]>
  * Copyright (c) 2014 Markus Friedl.  All rights reserved.
@@ -230,8 +230,7 @@ ssh_digest_free(struct ssh_digest_ctx *ctx)
 		if (digest) {
 			explicit_bzero(ctx->mdctx, digest->ctx_len);
 			free(ctx->mdctx);
-			explicit_bzero(ctx, sizeof(*ctx));
-			free(ctx);
+			freezero(ctx, sizeof(*ctx));
 		}
 	}
 }

hmac.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: hmac.c,v 1.13 2019/09/06 04:53:27 djm Exp $ */
+/* $OpenBSD: hmac.c,v 1.14 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright (c) 2014 Markus Friedl.  All rights reserved.
  *
@@ -131,8 +131,7 @@ ssh_hmac_free(struct ssh_hmac_ctx *ctx)
 			explicit_bzero(ctx->buf, ctx->buf_len);
 			free(ctx->buf);
 		}
-		explicit_bzero(ctx, sizeof(*ctx));
-		free(ctx);
+		freezero(ctx, sizeof(*ctx));
 	}
 }
 

hostfile.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: hostfile.c,v 1.77 2020/01/25 00:21:08 djm Exp $ */
+/* $OpenBSD: hostfile.c,v 1.78 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -298,8 +298,7 @@ free_hostkeys(struct hostkeys *hostkeys)
 		explicit_bzero(hostkeys->entries + i, sizeof(*hostkeys->entries));
 	}
 	free(hostkeys->entries);
-	explicit_bzero(hostkeys, sizeof(*hostkeys));
-	free(hostkeys);
+	freezero(hostkeys, sizeof(*hostkeys));
 }
 
 static int

kex.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.c,v 1.156 2020/01/23 10:24:29 dtucker Exp $ */
+/* $OpenBSD: kex.c,v 1.157 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  *
@@ -670,8 +670,7 @@ kex_free_newkeys(struct newkeys *newkeys)
 	}
 	free(newkeys->mac.name);
 	explicit_bzero(&newkeys->mac, sizeof(newkeys->mac));
-	explicit_bzero(newkeys, sizeof(*newkeys));
-	free(newkeys);
+	freezero(newkeys, sizeof(*newkeys));
 }
 
 void

monitor.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor.c,v 1.208 2020/02/06 22:30:54 naddy Exp $ */
+/* $OpenBSD: monitor.c,v 1.209 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright 2002 Niels Provos <[email protected]>
  * Copyright 2002 Markus Friedl <[email protected]>
@@ -893,8 +893,7 @@ mm_answer_authpassword(struct ssh *ssh, int sock, struct sshbuf *m)
 	/* Only authenticate if the context is valid */
 	authenticated = options.password_authentication &&
 	    auth_password(ssh, passwd);
-	explicit_bzero(passwd, plen);
-	free(passwd);
+	freezero(passwd, plen);
 
 	sshbuf_reset(m);
 	if ((r = sshbuf_put_u32(m, authenticated)) != 0)

ssh-add.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-add.c,v 1.153 2020/02/18 08:58:33 dtucker Exp $ */
+/* $OpenBSD: ssh-add.c,v 1.154 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -105,8 +105,7 @@ static void
 clear_pass(void)
 {
 	if (pass) {
-		explicit_bzero(pass, strlen(pass));
-		free(pass);
+		freezero(pass, strlen(pass));
 		pass = NULL;
 	}
 }
@@ -521,8 +520,7 @@ lock_agent(int agent_fd, int lock)
 			fprintf(stderr, "Passwords do not match.\n");
 			passok = 0;
 		}
-		explicit_bzero(p2, strlen(p2));
-		free(p2);
+		freezero(p2, strlen(p2));
 	}
 	if (passok) {
 		if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) {
@@ -533,8 +531,7 @@ lock_agent(int agent_fd, int lock)
 			    lock ? "" : "un", ssh_err(r));
 		}
 	}
-	explicit_bzero(p1, strlen(p1));
-	free(p1);
+	freezero(p1, strlen(p1));
 	return (ret);
 }
 

ssh-agent.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-agent.c,v 1.255 2020/02/06 22:30:54 naddy Exp $ */
+/* $OpenBSD: ssh-agent.c,v 1.256 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -620,8 +620,7 @@ process_lock_agent(SocketEntry *e, int lock)
 			fatal("bcrypt_pbkdf");
 		success = 1;
 	}
-	explicit_bzero(passwd, pwlen);
-	free(passwd);
+	freezero(passwd, pwlen);
 	send_status(e, success);
 }
 

ssh-dss.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-dss.c,v 1.37 2018/02/07 02:06:51 jsing Exp $ */
+/* $OpenBSD: ssh-dss.c,v 1.39 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -200,10 +200,8 @@ ssh_dss_verify(const struct sshkey *key,
 	BN_clear_free(sig_s);
 	sshbuf_free(b);
 	free(ktype);
-	if (sigblob != NULL) {
-		explicit_bzero(sigblob, len);
-		free(sigblob);
-	}
+	if (sigblob != NULL)
+		freezero(sigblob, len);
 	return ret;
 }
 #endif /* WITH_OPENSSL */

ssh-ed25519-sk.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-ed25519-sk.c,v 1.4 2019/11/26 03:04:27 djm Exp $ */
+/* $OpenBSD: ssh-ed25519-sk.c,v 1.5 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright (c) 2019 Markus Friedl.  All rights reserved.
  *
@@ -154,10 +154,8 @@ ssh_ed25519_sk_verify(const struct sshkey *key,
 		details = NULL;
 	}
  out:
-	if (m != NULL) {
-		explicit_bzero(m, smlen); /* NB mlen may be invalid if r != 0 */
-		free(m);
-	}
+	if (m != NULL)
+		freezero(m, smlen); /* NB mlen may be invalid if r != 0 */
 	sshkey_sig_details_free(details);
 	sshbuf_free(b);
 	sshbuf_free(encoded);

ssh-ed25519.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-ed25519.c,v 1.7 2016/04/21 06:08:02 djm Exp $ */
+/* $OpenBSD: ssh-ed25519.c,v 1.8 2020/02/26 13:40:09 jsg Exp $ */
 /*
  * Copyright (c) 2013 Markus Friedl <[email protected]>
  *
@@ -83,10 +83,8 @@ ssh_ed25519_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
 	r = 0;
  out:
 	sshbuf_free(b);
-	if (sig != NULL) {
-		explicit_bzero(sig, slen);
-		free(sig);
-	}
+	if (sig != NULL) 
+		freezero(sig, slen);
 
 	return r;
 }
@@ -153,14 +151,10 @@ ssh_ed25519_verify(const struct sshkey *key,
 	/* success */
 	r = 0;
  out:
-	if (sm != NULL) {
-		explicit_bzero(sm, smlen);
-		free(sm);
-	}
-	if (m != NULL) {
-		explicit_bzero(m, smlen); /* NB mlen may be invalid if r != 0 */
-		free(m);
-	}
+	if (sm != NULL) 
+		freezero(sm, smlen);
+	if (m != NULL) 
+		freezero(m, smlen); /* NB mlen may be invalid if r != 0 */
 	sshbuf_free(b);
 	free(ktype);
 	return r;