gpg: Do not allow to accidently set the RENC usage.

* g10/keygen.c (print_key_flags): Print "RENC" if set.
(ask_key_flags_with_mask): Remove RENC from the possible set of
usages.  Add a direct way to set it iff the key is encryption capable.
--

This could be done by using "set your own capabilities" for an RSA
key.  In fact it was always set in this case.

GnuPG-bug-id: 7072

1 files changed, 13 insertions, 1 deletions

diff --git a/g10/keygen.c b/g10/keygen.c
index c8487be0a..52fd97a64 100644
--- a/g10/keygen.c
+++ b/g10/keygen.c
@@ -1859,6 +1859,9 @@ print_key_flags(int flags)
 
   if(flags&PUBKEY_USAGE_AUTH)
     tty_printf("%s ",_("Authenticate"));
+
+  if(flags&PUBKEY_USAGE_RENC)
+    tty_printf("%s ", "RENC");
 }
 
 
@@ -1892,8 +1895,11 @@ ask_key_flags_with_mask (int algo, int subkey, unsigned int current,
     }
 
   /* Mask the possible usage flags.  This is for example used for a
-   * card based key.  */
+   * card based key.  For ECDH we need to allows additional usages if
+   * they are provided.  RENC is not directly poissible here but see
+   * below for a workaround. */
   possible = (openpgp_pk_algo_usage (algo) & mask);
+  possible &= ~PUBKEY_USAGE_RENC;
 
   /* However, only primary keys may certify. */
   if (subkey)
@@ -1956,6 +1962,12 @@ ask_key_flags_with_mask (int algo, int subkey, unsigned int current,
                      want to experiment with a cert-only primary key.  */
                   current |= PUBKEY_USAGE_CERT;
                 }
+              else if ((*s == 'r' || *s == 'R') && (possible&PUBKEY_USAGE_ENC))
+                {
+                  /* Allow to set RENC or an encryption capable key.
+                   * This is on purpose not shown in the menu.  */
+                  current |= PUBKEY_USAGE_RENC;
+                }
             }
           break;
         }