- djm@cvs.openbsd.org 2010/08/04 06:07:11

     [ssh-keygen.1 ssh-keygen.c]
     Support CA keys in PKCS#11 tokens; feedback and ok markus@

3 files changed, 66 insertions, 13 deletions

diff --git a/ChangeLog b/ChangeLog
index 684c5233b..0eec9ed7c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -19,6 +19,9 @@
      commited the wrong version of the hostbased certificate diff; this
      version replaces some strlc{py,at} verbosity with xasprintf() at
      the request of markus@
+   - djm@cvs.openbsd.org 2010/08/04 06:07:11
+     [ssh-keygen.1 ssh-keygen.c]
+     Support CA keys in PKCS#11 tokens; feedback and ok markus@
 
 20100903
  - (dtucker) [monitor.c] Bug #1795: Initialize the values to be returned from
diff --git a/ssh-keygen.1 b/ssh-keygen.1
index c4464878d..9acd8f8c9 100644
--- a/ssh-keygen.1
+++ b/ssh-keygen.1
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: ssh-keygen.1,v 1.97 2010/07/15 21:20:38 schwarze Exp $
+.\"     $OpenBSD: ssh-keygen.1,v 1.98 2010/08/04 06:07:11 djm Exp $
 .\"
 .\"  -*- nroff -*-
 .\"
@@ -37,7 +37,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: July 15 2010 $
+.Dd $Mdocdate: August 4 2010 $
 .Dt SSH-KEYGEN 1
 .Os
 .Sh NAME
@@ -215,6 +215,11 @@ the passphrase if the key has one, and for the new comment.
 .It Fl D Ar pkcs11
 Download the RSA public keys provided by the PKCS#11 shared library
 .Ar pkcs11 .
+When used in combination with
+.Fl s ,
+this option indicates that a CA key resides in a PKCS#11 token (see the
+.Sx CERTIFICATES
+section for details).
 .It Fl e
 This option will read a private or public OpenSSH key file and
 print to stdout the key in one of the formats specified by the
@@ -553,7 +558,17 @@ option:
 .Pp
 The host certificate will be output to
 .Pa /path/to/host_key-cert.pub .
-In both cases,
+.Pp
+It is possible to sign using a CA key stored in a PKCS#11 token by
+providing the token library using
+.Fl D
+and identifying the CA key by providing its public half as an argument
+to
+.Fl s :
+.Pp
+.Dl $ ssh-keygen -s ca_key.pub -D libpkcs11.so -I key_id host_key.pub
+.Pp
+In all cases,
 .Ar key_id
 is a "key identifier" that is logged by the server when the certificate
 is used for authentication.
diff --git a/ssh-keygen.c b/ssh-keygen.c
index 4c60a659f..d90b1dfdd 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.196 2010/08/04 05:40:39 djm Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.197 2010/08/04 06:07:11 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -146,6 +146,8 @@ int print_generic = 0;
 
 char *key_type_name = NULL;
 
+/* Load key from this PKCS#11 provider */
+char *pkcs11provider = NULL;
 
 /* argv0 */
 extern char *__progname;
@@ -655,7 +657,7 @@ do_print_public(struct passwd *pw)
 }
 
 static void
-do_download(struct passwd *pw, char *pkcs11provider)
+do_download(struct passwd *pw)
 {
 #ifdef ENABLE_PKCS11
         Key **keys = NULL;
@@ -1318,6 +1320,35 @@ prepare_options_buf(Buffer *c, int which)
                 add_string_option(c, "source-address", certflags_src_addr);
 }
 
+static Key *
+load_pkcs11_key(char *path)
+{
+#ifdef ENABLE_PKCS11
+        Key **keys = NULL, *public, *private = NULL;
+        int i, nkeys;
+
+        if ((public = key_load_public(path, NULL)) == NULL)
+                fatal("Couldn't load CA public key \"%s\"", path);
+
+        nkeys = pkcs11_add_provider(pkcs11provider, identity_passphrase, &keys);
+        debug3("%s: %d keys", __func__, nkeys);
+        if (nkeys <= 0)
+                fatal("cannot read public key from pkcs11");
+        for (i = 0; i < nkeys; i++) {
+                if (key_equal_public(public, keys[i])) {
+                        private = keys[i];
+                        continue;
+                }
+                key_free(keys[i]);
+        }
+        xfree(keys);
+        key_free(public);
+        return private;
+#else
+        fatal("no pkcs11 support");
+#endif /* ENABLE_PKCS11 */
+}
+
 static void
 do_ca_sign(struct passwd *pw, int argc, char **argv)
 {
@@ -1328,11 +1359,6 @@ do_ca_sign(struct passwd *pw, int argc, char **argv)
         FILE *f;
         int v00 = 0; /* legacy keys */
 
-        tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
-        if ((ca = load_identity(tmp)) == NULL)
-                fatal("Couldn't load CA key \"%s\"", tmp);
-        xfree(tmp);
-
         if (key_type_name != NULL) {
                 switch (key_type_from_name(key_type_name)) {
                 case KEY_RSA_CERT_V00:
@@ -1352,6 +1378,15 @@ do_ca_sign(struct passwd *pw, int argc, char **argv)
                 }
         }
 
+        pkcs11_init(1);
+        tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
+        if (pkcs11provider != NULL) {
+                if ((ca = load_pkcs11_key(tmp)) == NULL)
+                        fatal("No PKCS#11 key matching %s found", ca_key_path);
+        } else if ((ca = load_identity(tmp)) == NULL)
+                fatal("Couldn't load CA key \"%s\"", tmp);
+        xfree(tmp);
+
         for (i = 0; i < argc; i++) {
                 /* Split list of principals */
                 n = 0;
@@ -1424,6 +1459,7 @@ do_ca_sign(struct passwd *pw, int argc, char **argv)
                 key_free(public);
                 xfree(out);
         }
+        pkcs11_terminate();
         exit(0);
 }
 
@@ -1725,8 +1761,7 @@ int
 main(int argc, char **argv)
 {
         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
-        char out_file[MAXPATHLEN], *pkcs11provider = NULL;
-        char *rr_hostname = NULL;
+        char out_file[MAXPATHLEN], *rr_hostname = NULL;
         Key *private, *public;
         struct passwd *pw;
         struct stat st;
@@ -2001,7 +2036,7 @@ main(int argc, char **argv)
                 }
         }
         if (pkcs11provider != NULL)
-                do_download(pw, pkcs11provider);
+                do_download(pw);
 
         if (do_gen_candidates) {
                 FILE *out = fopen(out_file, "w");