sm: In --gen-key with "key from card" show also the algorithm.

* sm/certreqgen-ui.c (gpgsm_gencertreq_tty): Get and show algo.
--

This extends the prompt to show something like

  Serial number of the card: FF020001008A77F6
  Available keys:
     (1) 4130F84FA3704F4645924AEC3FFA48AD26D33656 PIV.9A nistp384
     (2) AB2988FB8C227BCD5175BF92F66AA3A95AE83214 PIV.9E rsa2048
     (3) DB7DDAEAA88534BA45CCD7A9B761425103EA2090 PIV.9C rsa2048
     (4) BABB48C3D80ACCF9839F101DF2910966C8B988DF PIV.9D nistp256
  Your selection? 1

Having the algorithm here is helpful in particular because right now
we support only RSA with X.509.  Take care: PIV card based certificate
creation does not yet work.

Signed-off-by: Werner Koch <[email protected]>
(cherry picked from commit 0328976c94adc2c518c7a7763a35319a0000c5e2)

Note that 2.2 does not support PIV cards, but the feature also works
also with other cards.

1 files changed, 21 insertions, 1 deletions

diff --git a/sm/certreqgen-ui.c b/sm/certreqgen-ui.c
index 9772a3baf..b131d7db5 100644
--- a/sm/certreqgen-ui.c
+++ b/sm/certreqgen-ui.c
@@ -244,7 +244,27 @@ gpgsm_gencertreq_tty (ctrl_t ctrl, estream_t output_stream)
         {
           tty_printf (_("Available keys:\n"));
           for (count=1,sl=keypairlist; sl; sl = sl->next, count++)
-            tty_printf ("   (%d) %s\n", count, sl->d);
+            {
+              ksba_sexp_t pkey;
+              gcry_sexp_t s_pkey;
+              char *algostr = NULL;
+              const char *keyref;
+
+              keyref = strchr (sl->d, ' ');
+              if (keyref)
+                {
+                  keyref++;
+                  if (!gpgsm_agent_readkey (ctrl, 1, keyref, &pkey))
+                    {
+                      if (!gcry_sexp_new (&s_pkey, pkey, 0, 0))
+                        algostr = pubkey_algo_string (s_pkey);
+                      gcry_sexp_release (s_pkey);
+                    }
+                  xfree (pkey);
+                }
+              tty_printf ("   (%d) %s %s\n", count, sl->d, algostr);
+              xfree (algostr);
+            }
           xfree (answer);
           answer = tty_get (_("Your selection? "));
           tty_kill_prompt ();