upstream: load_hostkeys()/hostkeys_foreach() variants for FILE*

Add load_hostkeys_file() and hostkeys_foreach_file() that accept a
FILE* argument instead of opening the file directly.

Original load_hostkeys() and hostkeys_foreach() are implemented using
these new interfaces.

Add a u_int note field to the hostkey_entry and hostkey_foreach_line
structs that is passed directly from the load_hostkeys() and
hostkeys_foreach() call. This is a lightweight way to annotate results
between different invocations of load_hostkeys().

ok markus@

OpenBSD-Commit-ID: 6ff6db13ec9ee4edfa658b2c38baad0f505d8c20

7 files changed, 76 insertions, 34 deletions

diff --git a/auth.c b/auth.c
index e82d7fea..e1bf4e75 100644
--- a/auth.c
+++ b/auth.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth.c,v 1.149 2020/10/18 11:32:01 djm Exp $ */
+/* $OpenBSD: auth.c,v 1.150 2020/12/20 23:36:51 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -468,7 +468,7 @@ check_key_in_hostfiles(struct passwd *pw, struct sshkey *key, const char *host,
 	const struct hostkey_entry *found;
 
 	hostkeys = init_hostkeys();
-	load_hostkeys(hostkeys, host, sysfile);
+	load_hostkeys(hostkeys, host, sysfile, 0);
 	if (userfile != NULL) {
 		user_hostfile = tilde_expand_filename(userfile, pw->pw_uid);
 		if (options.strict_modes &&
@@ -482,7 +482,7 @@ check_key_in_hostfiles(struct passwd *pw, struct sshkey *key, const char *host,
 			    user_hostfile);
 		} else {
 			temporarily_use_uid(pw);
-			load_hostkeys(hostkeys, host, user_hostfile);
+			load_hostkeys(hostkeys, host, user_hostfile, 0);
 			restore_uid();
 		}
 		free(user_hostfile);
diff --git a/clientloop.c b/clientloop.c
index c49eed39..63ba59f0 100644
--- a/clientloop.c
+++ b/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.355 2020/10/29 02:47:23 djm Exp $ */
+/* $OpenBSD: clientloop.c,v 1.356 2020/12/20 23:36:51 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1984,7 +1984,7 @@ check_old_keys_othernames(struct hostkeys_update_ctx *ctx)
 		    ctx->ip_str ? ctx->ip_str : "(none)");
 		if ((r = hostkeys_foreach(options.user_hostfiles[i],
 		    hostkeys_check_old, ctx, ctx->host_str, ctx->ip_str,
-		    HKF_WANT_PARSE_KEY)) != 0) {
+		    HKF_WANT_PARSE_KEY, 0)) != 0) {
 			if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
 				debug_f("hostkeys file %s does not exist",
 				    options.user_hostfiles[i]);
@@ -2298,7 +2298,7 @@ client_input_hostkeys(struct ssh *ssh)
 		    ctx->ip_str ? ctx->ip_str : "(none)");
 		if ((r = hostkeys_foreach(options.user_hostfiles[i],
 		    hostkeys_find, ctx, ctx->host_str, ctx->ip_str,
-		    HKF_WANT_PARSE_KEY)) != 0) {
+		    HKF_WANT_PARSE_KEY, 0)) != 0) {
 			if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
 				debug_f("hostkeys file %s does not exist",
 				    options.user_hostfiles[i]);
diff --git a/hostfile.c b/hostfile.c
index 4ec7b671..c3a28178 100644
--- a/hostfile.c
+++ b/hostfile.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: hostfile.c,v 1.86 2020/10/18 11:32:01 djm Exp $ */
+/* $OpenBSD: hostfile.c,v 1.87 2020/12/20 23:36:51 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -260,6 +260,7 @@ record_hostkey(struct hostkey_foreach_line *l, void *_ctx)
 	hostkeys->entries[hostkeys->num_entries].key = l->key;
 	l->key = NULL; /* steal it */
 	hostkeys->entries[hostkeys->num_entries].marker = l->marker;
+	hostkeys->entries[hostkeys->num_entries].note = l->note;
 	hostkeys->num_entries++;
 	ctx->num_loaded++;
 
@@ -267,7 +268,8 @@ record_hostkey(struct hostkey_foreach_line *l, void *_ctx)
 }
 
 void
-load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path)
+load_hostkeys_file(struct hostkeys *hostkeys, const char *host,
+    const char *path, FILE *f, u_int note)
 {
 	int r;
 	struct load_callback_ctx ctx;
@@ -276,8 +278,8 @@ load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path)
 	ctx.num_loaded = 0;
 	ctx.hostkeys = hostkeys;
 
-	if ((r = hostkeys_foreach(path, record_hostkey, &ctx, host, NULL,
-	    HKF_WANT_MATCH|HKF_WANT_PARSE_KEY)) != 0) {
+	if ((r = hostkeys_foreach_file(path, f, record_hostkey, &ctx, host,
+	    NULL, HKF_WANT_MATCH|HKF_WANT_PARSE_KEY, note)) != 0) {
 		if (r != SSH_ERR_SYSTEM_ERROR && errno != ENOENT)
 			debug_fr(r, "hostkeys_foreach failed for %s", path);
 	}
@@ -286,6 +288,21 @@ load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path)
 }
 
 void
+load_hostkeys(struct hostkeys *hostkeys, const char *host, const char *path,
+    u_int note)
+{
+	FILE *f;
+
+	if ((f = fopen(path, "r")) == NULL) {
+		debug_f("fopen %s: %s", path, strerror(errno));
+		return;
+	}
+
+	load_hostkeys_file(hostkeys, host, path, f, note);
+	fclose(f);
+}
+
+void
 free_hostkeys(struct hostkeys *hostkeys)
 {
 	u_int i;
@@ -620,7 +637,7 @@ hostfile_replace_entries(const char *filename, const char *host, const char *ip,
 
 	/* Remove stale/mismatching entries for the specified host */
 	if ((r = hostkeys_foreach(filename, host_delete, &ctx, host, ip,
-	    HKF_WANT_PARSE_KEY)) != 0) {
+	    HKF_WANT_PARSE_KEY, 0)) != 0) {
 		oerrno = errno;
 		error_fr(r, "hostkeys_foreach");
 		goto fail;
@@ -733,10 +750,9 @@ match_maybe_hashed(const char *host, const char *names, int *was_hashed)
 }
 
 int
-hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
-    const char *host, const char *ip, u_int options)
+hostkeys_foreach_file(const char *path, FILE *f, hostkeys_foreach_fn *callback,
+    void *ctx, const char *host, const char *ip, u_int options, u_int note)
 {
-	FILE *f;
 	char *line = NULL, ktype[128];
 	u_long linenum = 0;
 	char *cp, *cp2;
@@ -749,10 +765,7 @@ hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
 	memset(&lineinfo, 0, sizeof(lineinfo));
 	if (host == NULL && (options & HKF_WANT_MATCH) != 0)
 		return SSH_ERR_INVALID_ARGUMENT;
-	if ((f = fopen(path, "r")) == NULL)
-		return SSH_ERR_SYSTEM_ERROR;
 
-	debug3_f("reading file \"%s\"", path);
 	while (getline(&line, &linesize, f) != -1) {
 		linenum++;
 		line[strcspn(line, "\n")] = '\0';
@@ -766,6 +779,7 @@ hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
 		lineinfo.marker = MRK_NONE;
 		lineinfo.status = HKF_STATUS_OK;
 		lineinfo.keytype = KEY_UNSPEC;
+		lineinfo.note = note;
 
 		/* Skip any leading whitespace, comments and empty lines. */
 		for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
@@ -902,6 +916,24 @@ hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
 	sshkey_free(lineinfo.key);
 	free(lineinfo.line);
 	free(line);
+	return r;
+}
+
+int
+hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
+    const char *host, const char *ip, u_int options, u_int note)
+{
+	FILE *f;
+	int r, oerrno;
+
+	if ((f = fopen(path, "r")) == NULL)
+		return SSH_ERR_SYSTEM_ERROR;
+
+	debug3_f("reading file \"%s\"", path);
+	r = hostkeys_foreach_file(path, f, callback, ctx, host, ip,
+	    options, note);
+	oerrno = errno;
 	fclose(f);
+	errno = oerrno;
 	return r;
 }
diff --git a/hostfile.h b/hostfile.h
index 7ea31444..bc828ecc 100644
--- a/hostfile.h
+++ b/hostfile.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: hostfile.h,v 1.27 2020/10/04 09:45:01 djm Exp $ */
+/* $OpenBSD: hostfile.h,v 1.28 2020/12/20 23:36:51 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -28,11 +28,15 @@ struct hostkey_entry {
 	u_long line;
 	struct sshkey *key;
 	HostkeyMarker marker;
+	u_int note; /* caller-specific note/flag */
 };
 struct hostkeys;
 
 struct hostkeys *init_hostkeys(void);
-void	 load_hostkeys(struct hostkeys *, const char *, const char *);
+void	 load_hostkeys(struct hostkeys *, const char *,
+    const char *, u_int);
+void	 load_hostkeys_file(struct hostkeys *, const char *,
+    const char *, FILE *, u_int note);
 void	 free_hostkeys(struct hostkeys *);
 
 HostStatus check_key_in_hostkeys(struct hostkeys *, struct sshkey *,
@@ -93,6 +97,7 @@ struct hostkey_foreach_line {
 	int keytype;	/* Type of key; KEY_UNSPEC for invalid/comment lines */
 	struct sshkey *key; /* Key, if parsed ok and HKF_WANT_MATCH_HOST set */
 	const char *comment; /* Any comment following the key */
+	u_int note;	/* caller-specified note copied from arguments */
 };
 
 /*
@@ -103,8 +108,12 @@ struct hostkey_foreach_line {
 typedef int hostkeys_foreach_fn(struct hostkey_foreach_line *l, void *ctx);
 
 /* Iterate over a hostkeys file */
-int hostkeys_foreach(const char *path, hostkeys_foreach_fn *callback, void *ctx,
-    const char *host, const char *ip, u_int options);
+int hostkeys_foreach(const char *path,
+    hostkeys_foreach_fn *callback, void *ctx,
+    const char *host, const char *ip, u_int options, u_int note);
+int hostkeys_foreach_file(const char *path, FILE *f,
+    hostkeys_foreach_fn *callback, void *ctx,
+    const char *host, const char *ip, u_int options, u_int note);
 
 void hostfile_create_user_ssh_dir(const char *, int);
 
diff --git a/ssh-keygen.c b/ssh-keygen.c
index 634e1ee3..cfb5f115 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.426 2020/11/28 12:52:32 dtucker Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.427 2020/12/20 23:36:51 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1341,7 +1341,7 @@ do_known_hosts(struct passwd *pw, const char *name, int find_host,
 	foreach_options |= print_fingerprint ? HKF_WANT_PARSE_KEY : 0;
 	if ((r = hostkeys_foreach(identity_file, (find_host || !hash_hosts) ?
 	    known_hosts_find_delete : known_hosts_hash, &ctx, name, NULL,
-	    foreach_options)) != 0) {
+	    foreach_options, 0)) != 0) {
 		if (inplace)
 			unlink(tmp);
 		fatal_fr(r, "hostkeys_foreach");
diff --git a/sshconnect.c b/sshconnect.c
index 6b60ca0d..59211416 100644
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.345 2020/11/27 00:49:58 djm Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.346 2020/12/20 23:36:51 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -773,7 +773,7 @@ hostkeys_find_by_key_hostfile(const char *file, const char *which,
 
 	debug3_f("trying %s hostfile \"%s\"", which, file);
 	if ((r = hostkeys_foreach(file, hostkeys_find_by_key_cb, ctx,
-	    ctx->host, ctx->ip, HKF_WANT_PARSE_KEY)) != 0) {
+	    ctx->host, ctx->ip, HKF_WANT_PARSE_KEY, 0)) != 0) {
 		if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
 			debug_f("hostkeys file %s does not exist", file);
 			return 0;
@@ -924,17 +924,17 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
 
 	host_hostkeys = init_hostkeys();
 	for (i = 0; i < num_user_hostfiles; i++)
-		load_hostkeys(host_hostkeys, host, user_hostfiles[i]);
+		load_hostkeys(host_hostkeys, host, user_hostfiles[i], 0);
 	for (i = 0; i < num_system_hostfiles; i++)
-		load_hostkeys(host_hostkeys, host, system_hostfiles[i]);
+		load_hostkeys(host_hostkeys, host, system_hostfiles[i], 0);
 
 	ip_hostkeys = NULL;
 	if (!want_cert && options.check_host_ip) {
 		ip_hostkeys = init_hostkeys();
 		for (i = 0; i < num_user_hostfiles; i++)
-			load_hostkeys(ip_hostkeys, ip, user_hostfiles[i]);
+			load_hostkeys(ip_hostkeys, ip, user_hostfiles[i], 0);
 		for (i = 0; i < num_system_hostfiles; i++)
-			load_hostkeys(ip_hostkeys, ip, system_hostfiles[i]);
+			load_hostkeys(ip_hostkeys, ip, system_hostfiles[i], 0);
 	}
 
  retry:
diff --git a/sshconnect2.c b/sshconnect2.c
index 149bb8d6..afbb8526 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect2.c,v 1.336 2020/11/13 07:30:44 djm Exp $ */
+/* $OpenBSD: sshconnect2.c,v 1.337 2020/12/20 23:36:51 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Damien Miller.  All rights reserved.
@@ -129,10 +129,11 @@ order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
 	get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
 	hostkeys = init_hostkeys();
 	for (i = 0; i < options.num_user_hostfiles; i++)
-		load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
-	for (i = 0; i < options.num_system_hostfiles; i++)
-		load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
-
+		load_hostkeys(hostkeys, hostname, options.user_hostfiles[i], 0);
+	for (i = 0; i < options.num_system_hostfiles; i++) {
+		load_hostkeys(hostkeys, hostname,
+		    options.system_hostfiles[i], 0);
+	}
 	/*
 	 * If a plain public key exists that matches the type of the best
 	 * preference HostkeyAlgorithms, then use the whole list as is.