From ec76b3cef0014c6aa68ec8982101892c74958b99 Mon Sep 17 00:00:00 2001
From: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Date: Sat, 7 Jun 2008 19:27:51 -0400
Subject: [PATCH] updated gpg2ssh to properly check for data encryption and
 authentication.

---
 gpg2ssh/Makefile  |  6 ++++--
 gpg2ssh/gpg2ssh.c | 14 ++++++++------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/gpg2ssh/Makefile b/gpg2ssh/Makefile
index aa18aaa..a0b7241 100644
--- a/gpg2ssh/Makefile
+++ b/gpg2ssh/Makefile
@@ -1,3 +1,5 @@
+all: monkeysphere gpg2ssh
+
 monkeysphere: main.c gnutls-helpers.o
 	gcc -g -Wall --pedantic -o monkeysphere main.c `libgnutls-config --libs --cflags` -lgnutls-extra gnutls-helpers.o
 
@@ -11,6 +13,6 @@ ssh2gpg: ssh2gpg.c gnutls-helpers.o
 	gcc -g -Wall --pedantic -o $@ -c $<
 
 clean: 
-	rm -f monkeysphere *.o
+	rm -f monkeysphere gpg2ssh *.o
 
-.PHONY: clean
+.PHONY: clean all
diff --git a/gpg2ssh/gpg2ssh.c b/gpg2ssh/gpg2ssh.c
index a1e94df..c99f03f 100644
--- a/gpg2ssh/gpg2ssh.c
+++ b/gpg2ssh/gpg2ssh.c
@@ -116,8 +116,9 @@ int main(int argc, char* argv[]) {
     err("failed to get the usage flags for the primary key (error: %d)\n", ret);
     return ret;
   }
-  if (usage & GNUTLS_KEY_KEY_AGREEMENT) {
-    err("the primary key can be used for authentication\n");
+  if (usage & GNUTLS_KEY_KEY_AGREEMENT &&
+      usage & GNUTLS_KEY_KEY_ENCIPHERMENT) {
+    err("the primary key can be used for authentication and communication encryption!\n");
 
     algo = gnutls_openpgp_crt_get_pk_algorithm(openpgp_crt, &bits);
     if (algo < 0) {
@@ -144,10 +145,10 @@ int main(int argc, char* argv[]) {
     }
     
   } else {
-    err("primary key is only good for: 0x%08x.  Trying subkeys...\n", usage);
+    err("primary key is not good for authentication and communication encryption.  Trying subkeys...\n");
     
     if (ret = gnutls_openpgp_crt_get_auth_subkey(openpgp_crt, keyid, 0), ret) {
-      err("failed to find a subkey capable of authentication (error: %d)\n", ret);
+      err("failed to find a subkey capable of authentication and communication encryption (error: %d)\n", ret);
       return ret;
     }
     make_keyid_printable(p_keyid, keyid);
@@ -169,8 +170,9 @@ int main(int argc, char* argv[]) {
       err("could not figure out usage of subkey %.16s (error: %d)\n", p_keyid, ret);
       return ret;
     }
-    if ((usage & GNUTLS_KEY_KEY_AGREEMENT) == 0) {
-      err("could not find a subkey with authentication privileges.\n");
+    if ((usage & GNUTLS_KEY_KEY_AGREEMENT) == 0 &&
+	usage & GNUTLS_KEY_KEY_ENCIPHERMENT) {
+      err("could not find a subkey with authentication and communication encryption.\n");
       return 1;
     }
 
-- 
2.25.1