* 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/auth-rsa.c b/auth-rsa.c
index 69f9a5896..1d277f92a 100644
--- a/auth-rsa.c
+++ b/auth-rsa.c
@@ -40,6 +40,7 @@
 #include "servconf.h"
 #include "key.h"
 #include "hostfile.h"
+#include "authfile.h"
 #include "auth.h"
 #ifdef GSSAPI
 #include "ssh-gss.h"
@@ -221,6 +222,7 @@ auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
                 char *cp;
                 char *key_options;
                 int keybits;
+                char *fp;
 
                 /* Skip leading whitespace, empty and comment lines. */
                 for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
@@ -265,6 +267,19 @@ auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
                             "actual %d vs. announced %d.",
                             file, linenum, BN_num_bits(key->rsa->n), bits);
 
+                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)
+                                continue;
+                }
+
                 /* We have found the desired key. */
                 /*
                  * If our options do not allow this key to be used,