* Mitigate OpenSSL security vulnerability:

  - Add key blacklisting support. Keys listed in
    /etc/ssh/blacklist.TYPE-LENGTH will be rejected for authentication by
    sshd, unless "PermitBlacklistedKeys yes" is set in
    /etc/ssh/sshd_config.
  - Add a new program, ssh-vulnkey, which can be used to check keys
    against these blacklists.
  - Depend on openssh-blacklist.
  - Force dependencies on libssl0.9.8 / libcrypto0.9.8-udeb to at least
    0.9.8g-9.
  - Automatically regenerate known-compromised host keys, with a
    critical-priority debconf note. (I regret that there was no time to
    gather translations.)

1 files changed, 15 insertions, 0 deletions

diff --git a/auth2-pubkey.c b/auth2-pubkey.c
index 9863cd9e6..cf911968a 100644
--- a/auth2-pubkey.c
+++ b/auth2-pubkey.c
@@ -42,6 +42,7 @@
 #include "compat.h"
 #include "key.h"
 #include "hostfile.h"
+#include "authfile.h"
 #include "auth.h"
 #include "pathnames.h"
 #include "uidswap.h"
@@ -269,9 +270,23 @@ user_key_allowed2(struct passwd *pw, Key *key, char *file)
 int
 user_key_allowed(struct passwd *pw, Key *key)
 {
+        char *fp;
         int success;
         char *file;
 
+        if (blacklisted_key(key)) {
+                fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
+                if (options.permit_blacklisted_keys)
+                        logit("Public key %s blacklisted (see "
+                            "ssh-vulnkey(1)); continuing anyway", fp);
+                else
+                        logit("Public key %s blacklisted (see "
+                            "ssh-vulnkey(1))", fp);
+                xfree(fp);
+                if (!options.permit_blacklisted_keys)
+                        return 0;
+        }
+
         file = authorized_keys_file(pw);
         success = user_key_allowed2(pw, key, file);
         xfree(file);