scd: Extend KEYPAIRINFO with an algorithm string.

* scd/app-openpgp.c (send_keypair_info): Emit the algo string as part
of a KEYPAIRINFO.
* scd/command.c (do_readkey): Ditto.
* scd/app-piv.c (do_readkey): Ditto.
* scd/app-nks.c (do_learn_status_core): Ditto.
(struct fid_cache_s): Add field algostr.
(flush_fid_cache): Release it.
(keygripstr_from_pk_file): Fill it and add it to the cache.  Use a
single exit label.
* scd/app-help.c (app_help_get_keygrip_string_pk): Add new arg
r_algostr.  Change all callers.
--

This is helpful so that callers do not need to parse the key for this
basic information.  Use "scd readkey --info-only" to return the info
status line instead of the key material; using just --info returns the
info in addition to the key material.

Signed-off-by: Werner Koch <[email protected]>

1 files changed, 21 insertions, 2 deletions

diff --git a/scd/app-openpgp.c b/scd/app-openpgp.c
index 465819adc..c631383c0 100644
--- a/scd/app-openpgp.c
+++ b/scd/app-openpgp.c
@@ -2049,6 +2049,7 @@ send_keypair_info (app_t app, ctrl_t ctrl, int key)
   gpg_error_t err = 0;
   const char *usage;
   u32 fprtime;
+  char *algostr = NULL;
 
   err = get_public_key (app, keyno);
   if (err)
@@ -2069,11 +2070,29 @@ send_keypair_info (app_t app, ctrl_t ctrl, int key)
   if (retrieve_fprtime_from_card (app, keyno, &fprtime))
     fprtime = 0;
 
-  err = send_status_printf (ctrl, "KEYPAIRINFO", "%s OPENPGP.%d %s %lu",
+  {
+    gcry_sexp_t s_pkey;
+    if (gcry_sexp_new (&s_pkey, app->app_local->pk[keyno].key,
+                       app->app_local->pk[keyno].keylen, 0))
+      algostr = xtrystrdup ("?");
+    else
+      {
+        algostr = pubkey_algo_string (s_pkey, NULL);
+        gcry_sexp_release (s_pkey);
+      }
+  }
+  if (!algostr)
+    {
+      err = gpg_error_from_syserror ();
+      goto leave;
+    }
+
+  err = send_status_printf (ctrl, "KEYPAIRINFO", "%s OPENPGP.%d %s %lu %s",
                             app->app_local->pk[keyno].keygrip_str,
-                            keyno+1, usage, (unsigned long)fprtime);
+                            keyno+1, usage, (unsigned long)fprtime, algostr);
 
  leave:
+  xfree (algostr);
   return err;
 }