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, 18 insertions, 3 deletions

diff --git a/scd/app-help.c b/scd/app-help.c
index f2b592399..b599add71 100644
--- a/scd/app-help.c
+++ b/scd/app-help.c
@@ -57,10 +57,12 @@ app_help_count_bits (const unsigned char *a, size_t len)
  * function succeeded, the S-expression representing the key is stored
  * there.  The caller needs to call gcry_sexp_release on that.  If
  * R_ALGO is not NULL the public key algorithm id of Libgcrypt is
- * stored there.  */
+ * stored there.  If R_ALGOSTR is not NULL and the function succeeds a
+ * newly allocated algo string (e.g. "rsa2048") is stored there. */
 gpg_error_t
 app_help_get_keygrip_string_pk (const void *pk, size_t pklen, char *hexkeygrip,
-                                gcry_sexp_t *r_pkey, int *r_algo)
+                                gcry_sexp_t *r_pkey, int *r_algo,
+                                char **r_algostr)
 {
   gpg_error_t err;
   gcry_sexp_t s_pkey;
@@ -68,6 +70,8 @@ app_help_get_keygrip_string_pk (const void *pk, size_t pklen, char *hexkeygrip,
 
   if (r_pkey)
     *r_pkey = NULL;
+  if (r_algostr)
+    *r_algostr = NULL;
 
   err = gcry_sexp_sscan (&s_pkey, NULL, pk, pklen);
   if (err)
@@ -81,6 +85,17 @@ app_help_get_keygrip_string_pk (const void *pk, size_t pklen, char *hexkeygrip,
   if (r_algo)
     *r_algo = get_pk_algo_from_key (s_pkey);
 
+  if (r_algostr)
+    {
+      *r_algostr = pubkey_algo_string (s_pkey, NULL);
+      if (!*r_algostr)
+        {
+          err = gpg_error_from_syserror ();
+          gcry_sexp_release (s_pkey);
+          return err;
+        }
+    }
+
   if (r_pkey)
     *r_pkey = s_pkey;
   else
@@ -116,7 +131,7 @@ app_help_get_keygrip_string (ksba_cert_t cert, char *hexkeygrip,
   if (!n)
     return gpg_error (GPG_ERR_INV_SEXP);
   err = app_help_get_keygrip_string_pk ((void*)p, n, hexkeygrip,
-                                        r_pkey, r_algo);
+                                        r_pkey, r_algo, NULL);
   ksba_free (p);
   return err;
 }