Fix ssh-keygen -H accidentally corrupting known_hosts that contained already-hashed entries (closes: #851734, LP: #1668093).

2 files changed, 45 insertions, 0 deletions

diff --git a/debian/patches/series b/debian/patches/series
index 6f0004748..7ddc4a772 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -30,3 +30,4 @@ regress-mktemp.patch
 sandbox-x32-workaround.patch
 no-dsa-host-key-by-default.patch
 restore-authorized_keys2.patch
+ssh-keygen-hash-corruption.patch
diff --git a/debian/patches/ssh-keygen-hash-corruption.patch b/debian/patches/ssh-keygen-hash-corruption.patch
new file mode 100644
index 000000000..7ef3c637c
--- /dev/null
+++ b/debian/patches/ssh-keygen-hash-corruption.patch
@@ -0,0 +1,44 @@
+From 78800aa252da1ebbfb55f7e593f43c337e694cc3 Mon Sep 17 00:00:00 2001
+From: "djm@openbsd.org" <djm@openbsd.org>
+Date: Fri, 3 Mar 2017 06:13:11 +0000
+Subject: upstream commit
+
+fix ssh-keygen -H accidentally corrupting known_hosts that
+contained already-hashed entries. HKF_MATCH_HOST_HASHED is only set by
+hostkeys_foreach() when hostname matching is in use, so we need to look for
+the hash marker explicitly.
+
+Upstream-ID: da82ad653b93e8a753580d3cf5cd448bc2520528
+
+Origin: https://anongit.mindrot.org/openssh.git/commit/?id=12d3767ba4c84c32150cbe6ff6494498780f12c9
+Bug-Debian: https://bugs.debian.org/851734
+Bug-Ubuntu: https://bugs.launchpad.net/bugs/1668093
+Last-Update: 2017-03-09
+
+Patch-Name: ssh-keygen-hash-corruption.patch
+---
+ ssh-keygen.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/ssh-keygen.c b/ssh-keygen.c
+index 2a7939bf..0833ee61 100644
+--- a/ssh-keygen.c
++++ b/ssh-keygen.c
+@@ -1082,6 +1082,7 @@ known_hosts_hash(struct hostkey_foreach_line *l, void *_ctx)
+        struct known_hosts_ctx *ctx = (struct known_hosts_ctx *)_ctx;
+        char *hashed, *cp, *hosts, *ohosts;
+        int has_wild = l->hosts && strcspn(l->hosts, "*?!") != strlen(l->hosts);
++       int was_hashed = l->hosts[0] == HASH_DELIM;
+ 
+        switch (l->status) {
+        case HKF_STATUS_OK:
+@@ -1090,8 +1091,7 @@ known_hosts_hash(struct hostkey_foreach_line *l, void *_ctx)
+                 * Don't hash hosts already already hashed, with wildcard
+                 * characters or a CA/revocation marker.
+                 */
+-               if ((l->match & HKF_MATCH_HOST_HASHED) != 0 ||
+-                   has_wild || l->marker != MRK_NONE) {
++               if (was_hashed || has_wild || l->marker != MRK_NONE) {
+                        fprintf(ctx->out, "%s\n", l->line);
+                        if (has_wild && !find_host) {
+                                logit("%s:%ld: ignoring host name "