sm/

* gpgsm.c: New command --learn-card
* call-agent.c (learn_cb,gpgsm_agent_learn): New.
* gpgsm.c (main): Print error messages for non-implemented commands.
agent/
* learncard.c: New.
* divert-scd.c (ask_for_card): The serial number is binary so
convert it to hex here.
* findkey.c (agent_write_private_key): New.
* genkey.c (store_key): And use it here.
scd/
* pkdecrypt.c (agent_pkdecrypt): Changed the way the diversion is done.
* divert-scd.c (divert_pkdecrypt): Changed interface and
implemented it.

10 files changed, 462 insertions, 82 deletions

diff --git a/agent/ChangeLog b/agent/ChangeLog
index bc0ca11ef..cbc05b1e4 100644
--- a/agent/ChangeLog
+++ b/agent/ChangeLog
@@ -1,5 +1,11 @@
 2002-03-06  Werner Koch  <[email protected]>
 
+	* learncard.c: New.
+	* divert-scd.c (ask_for_card): The serial number is binary so
+	convert it to hex here.
+	* findkey.c (agent_write_private_key): New.
+	* genkey.c (store_key): And use it here.
+	
 	* pkdecrypt.c (agent_pkdecrypt): Changed the way the diversion is done.
 	* divert-scd.c (divert_pkdecrypt): Changed interface and
 	implemented it.
diff --git a/agent/Makefile.am b/agent/Makefile.am
index 7ee2fb398..5716519bf 100644
--- a/agent/Makefile.am
+++ b/agent/Makefile.am
@@ -38,6 +38,7 @@ gpg_agent_SOURCES = \
 	trustlist.c \
 	divert-scd.c \
 	call-scd.c \
+	learncard.c \
 	sexp-parse.h
 
 
diff --git a/agent/agent.h b/agent/agent.h
index 2d92f94be..2b5a2fa31 100644
--- a/agent/agent.h
+++ b/agent/agent.h
@@ -102,6 +102,8 @@ const char *trans (const char *text);
 void start_command_handler (int);
 
 /*-- findkey.c --*/
+int agent_write_private_key (const unsigned char *grip,
+                             const void *buffer, size_t length, int force);
 GCRY_SEXP agent_key_from_file (const unsigned char *grip,
                                unsigned char **shadow_info);
 int agent_key_available (const unsigned char *grip);
@@ -152,12 +154,14 @@ int agent_marktrusted (const char *name, const char *fpr, int flag);
 
 /*-- divert-scd.c --*/
 int divert_pksign (const unsigned char *digest, size_t digestlen, int algo,
-                   const char *shadow_info, unsigned char **r_sig);
-int divert_pkdecrypt (const unsigned char *cipher, const char *shadow_info,
+                   const unsigned char *shadow_info, unsigned char **r_sig);
+int divert_pkdecrypt (const unsigned char *cipher,
+                      const unsigned char *shadow_info,
                       char **r_buf, size_t *r_len);
 
 /*-- call-scd.c --*/
-int agent_card_learn (void);
+int agent_card_learn (void (*kpinfo_cb)(void*, const char *),
+                      void *kpinfo_cb_arg);
 int agent_card_serialno (char **r_serialno);
 int agent_card_pksign (const char *keyid,
                        int (*getpin_cb)(void *, const char *, char*, size_t),
@@ -169,6 +173,12 @@ int agent_card_pkdecrypt (const char *keyid,
                           void *getpin_cb_arg,
                           const unsigned char *indata, size_t indatalen,
                           char **r_buf, size_t *r_buflen);
+int agent_card_readcert (const char *id, char **r_buf, size_t *r_buflen);
+int agent_card_readkey (const char *id, unsigned char **r_buf);
+
+
+/*-- learncard.c --*/
+int agent_handle_learn (void *assuan_context);
 
 
 #endif /*AGENT_H*/
diff --git a/agent/call-scd.c b/agent/call-scd.c
index dd8853f22..040201f25 100644
--- a/agent/call-scd.c
+++ b/agent/call-scd.c
@@ -41,9 +41,8 @@ static ASSUAN_CONTEXT scd_ctx = NULL;
 
 /* callback parameter for learn card */
 struct learn_parm_s {
-  int lines;
-  size_t size;
-  char *buffer;
+  void (*kpinfo_cb)(void*, const char *);
+  void *kpinfo_cb_arg;
 };
 
 struct inq_needpin_s {
@@ -176,7 +175,7 @@ start_scd (void)
 static AssuanError
 learn_status_cb (void *opaque, const char *line)
 {
-  /*  struct learn_parm_s *parm = opaque;*/
+  struct learn_parm_s *parm = opaque;
   const char *keyword = line;
   int keywordlen;
 
@@ -186,7 +185,7 @@ learn_status_cb (void *opaque, const char *line)
     line++;
   if (keywordlen == 11 && !memcmp (keyword, "KEYPAIRINFO", keywordlen))
     {
-      log_debug ("learn_status_cb: keypair `%s'\n", line);
+      parm->kpinfo_cb (parm->kpinfo_cb_arg, line);
     }
   else if (keywordlen == 8 && !memcmp (keyword, "SERIALNO", keywordlen))
     {
@@ -201,7 +200,7 @@ learn_status_cb (void *opaque, const char *line)
 /* Perform the learn command and return a list of all private keys
    stored on the card. */
 int
-agent_card_learn (void)
+agent_card_learn (void (*kpinfo_cb)(void*, const char *), void *kpinfo_cb_arg)
 {
   int rc;
   struct learn_parm_s parm;
@@ -210,12 +209,9 @@ agent_card_learn (void)
   if (rc)
     return rc;
 
-  rc = assuan_transact (scd_ctx, "RESET", NULL, NULL, NULL, NULL, NULL, NULL);
-  if (rc)
-    return map_assuan_err (rc);
-
   memset (&parm, 0, sizeof parm);
-
+  parm.kpinfo_cb = kpinfo_cb;
+  parm.kpinfo_cb_arg = kpinfo_cb_arg;
   rc = assuan_transact (scd_ctx, "LEARN --force",
                         NULL, NULL, NULL, NULL,
                         learn_status_cb, &parm);
@@ -259,7 +255,7 @@ get_serialno_cb (void *opaque, const char *line)
 }
 
 /* Return the serial number of the card or an appropriate error.  The
-   serial number is returned as a hext string. */
+   serial number is returned as a hexstring. */
 int
 agent_card_serialno (char **r_serialno)
 {
@@ -296,7 +292,8 @@ membuf_data_cb (void *opaque, const void *buffer, size_t length)
 {
   struct membuf *data = opaque;
 
-  put_membuf (data, buffer, length);
+  if (buffer)
+    put_membuf (data, buffer, length);
   return 0;
 }
   
@@ -456,3 +453,82 @@ agent_card_pkdecrypt (const char *keyid,
   return 0;
 }
 
+
+
+/* Read a certificate with ID into R_BUF and R_BUFLEN. */
+int
+agent_card_readcert (const char *id, char **r_buf, size_t *r_buflen)
+{
+  int rc;
+  char line[ASSUAN_LINELENGTH];
+  struct membuf data;
+  size_t len;
+
+  *r_buf = NULL;
+  rc = start_scd ();
+  if (rc)
+    return rc;
+
+  init_membuf (&data, 1024);
+  snprintf (line, DIM(line)-1, "READCERT %s", id);
+  line[DIM(line)-1] = 0;
+  rc = assuan_transact (scd_ctx, line,
+                        membuf_data_cb, &data,
+                        NULL, NULL,
+                        NULL, NULL);
+  if (rc)
+    {
+      xfree (get_membuf (&data, &len));
+      return map_assuan_err (rc);
+    }
+  *r_buf = get_membuf (&data, r_buflen);
+  if (!*r_buf)
+    return GNUPG_Out_Of_Core;
+
+  return 0;
+}
+
+
+
+/* Read a key with ID and return it in an allocate buffer pointed to
+   by r_BUF as a valid S-expression. */
+int
+agent_card_readkey (const char *id, unsigned char **r_buf)
+{
+  int rc;
+  char line[ASSUAN_LINELENGTH];
+  struct membuf data;
+  size_t len, buflen;
+
+  *r_buf = NULL;
+  rc = start_scd ();
+  if (rc)
+    return rc;
+
+  init_membuf (&data, 1024);
+  snprintf (line, DIM(line)-1, "READKEY %s", id);
+  line[DIM(line)-1] = 0;
+  rc = assuan_transact (scd_ctx, line,
+                        membuf_data_cb, &data,
+                        NULL, NULL,
+                        NULL, NULL);
+  if (rc)
+    {
+      xfree (get_membuf (&data, &len));
+      return map_assuan_err (rc);
+    }
+  *r_buf = get_membuf (&data, &buflen);
+  if (!*r_buf)
+    return GNUPG_Out_Of_Core;
+
+  if (!gcry_sexp_canon_len (*r_buf, buflen, NULL, NULL))
+    {
+      xfree (*r_buf); *r_buf = NULL;
+      return GNUPG_Invalid_Value;
+    }
+
+  return 0;
+}
+
+
+
diff --git a/agent/command.c b/agent/command.c
index bed9da648..e617d684f 100644
--- a/agent/command.c
+++ b/agent/command.c
@@ -64,6 +64,21 @@ reset_notify (ASSUAN_CONTEXT ctx)
   ctrl->digest.valuelen = 0;
 }
 
+
+/* Check whether the option NAME appears in LINE */
+static int
+has_option (const char *line, const char *name)
+{
+  const char *s;
+  int n = strlen (name);
+
+  s = strstr (line, name);
+  return (s && (s == line || spacep (s-1)) && (!s[n] || spacep (s+n)));
+}
+
+
+
+
 /* ISTRUSTED <hexstring_with_fingerprint>
 
    Return OK when we have an entry with this fingerprint in our
@@ -463,18 +478,18 @@ cmd_clear_passphrase (ASSUAN_CONTEXT ctx, char *line)
 }
 
 
-/* LEARN
+/* LEARN [--send]
 
-   Learn something about the currently inserted smartcard 
- */
+   Learn something about the currently inserted smartcard.  With
+   --send the new certificates are send back.  */
 static int
 cmd_learn (ASSUAN_CONTEXT ctx, char *line)
 {
   int rc;
 
-  rc = agent_card_learn ();
+  rc = agent_handle_learn (has_option (line, "--send")? ctx : NULL);
   if (rc)
-    log_error ("agent_learn_card failed: %s\n", gnupg_strerror (rc));
+    log_error ("agent_handle_learn failed: %s\n", gnupg_strerror (rc));
   return map_to_assuan_status (rc);
 }
 
diff --git a/agent/divert-scd.c b/agent/divert-scd.c
index 33fd5ce26..9b176a6bd 100644
--- a/agent/divert-scd.c
+++ b/agent/divert-scd.c
@@ -52,11 +52,11 @@ ask_for_card (const unsigned char *shadow_info, char **r_kid)
   n = snext (&s);
   if (!n)
     return GNUPG_Invalid_Sexp;
-  want_sn = xtrymalloc (n+1);
+  want_sn = xtrymalloc (n*2+1);
   if (!want_sn)
     return GNUPG_Out_Of_Core;
-  memcpy (want_sn, s, n);
-  want_sn[n] = 0;
+  for (i=0; i < n; i++)
+    sprintf (want_sn+2*i, "%02X", s[i]);
   s += n;
 
   n = snext (&s);
@@ -229,7 +229,7 @@ getpin_cb (void *opaque, const char *info, char *buf, size_t maxbuf)
 
 int
 divert_pksign (const unsigned char *digest, size_t digestlen, int algo,
-               const char *shadow_info, unsigned char **r_sig)
+               const unsigned char *shadow_info, unsigned char **r_sig)
 {
   int rc;
   char *kid;
@@ -262,7 +262,8 @@ divert_pksign (const unsigned char *digest, size_t digestlen, int algo,
    key identified by SHADOW_INFO and return the plaintext in an
    allocated buffer in R_BUF.  */
 int  
-divert_pkdecrypt (const unsigned char *cipher, const char *shadow_info,
+divert_pkdecrypt (const unsigned char *cipher,
+                  const unsigned char *shadow_info,
                   char **r_buf, size_t *r_len)
 {
   int rc;
diff --git a/agent/findkey.c b/agent/findkey.c
index 14ad762d9..662a56f89 100644
--- a/agent/findkey.c
+++ b/agent/findkey.c
@@ -30,6 +30,64 @@
 
 #include "agent.h"
 
+
+int
+agent_write_private_key (const unsigned char *grip,
+                         const void *buffer, size_t length, int force)
+{
+  int i;
+  char *fname;
+  FILE *fp;
+  char hexgrip[40+4+1];
+  
+  for (i=0; i < 20; i++)
+    sprintf (hexgrip+2*i, "%02X", grip[i]);
+  strcpy (hexgrip+40, ".key");
+
+  fname = make_filename (opt.homedir, "private-keys-v1.d", hexgrip, NULL);
+  if (force)
+    fp = fopen (fname, "wb");
+  else
+    {
+      if (!access (fname, F_OK))
+      {
+        log_error ("secret key file `%s' already exists\n", fname);
+        xfree (fname);
+        return seterr (General_Error);
+      }
+      fp = fopen (fname, "wbx");  /* FIXME: the x is a GNU extension - let
+                                     configure check whether this actually
+                                     works */
+    }
+
+  if (!fp) 
+    { 
+      log_error ("can't create `%s': %s\n", fname, strerror (errno));
+      xfree (fname);
+      return seterr (File_Create_Error);
+    }
+
+  if (fwrite (buffer, length, 1, fp) != 1)
+    {
+      log_error ("error writing `%s': %s\n", fname, strerror (errno));
+      fclose (fp);
+      remove (fname);
+      xfree (fname);
+      return seterr (File_Create_Error);
+    }
+  if ( fclose (fp) )
+    {
+      log_error ("error closing `%s': %s\n", fname, strerror (errno));
+      remove (fname);
+      xfree (fname);
+      return seterr (File_Create_Error);
+    }
+
+  xfree (fname);
+  return 0;
+}
+
+
 static int
 unprotect (unsigned char **keybuf, const unsigned char *grip)
 {
diff --git a/agent/genkey.c b/agent/genkey.c
index 1aca33b83..ae46c4694 100644
--- a/agent/genkey.c
+++ b/agent/genkey.c
@@ -25,8 +25,6 @@
 #include <string.h>
 #include <ctype.h>
 #include <assert.h>
-#include <unistd.h>
-#include <sys/stat.h>
 
 #include "agent.h"
 
@@ -34,65 +32,32 @@
 static int
 store_key (GCRY_SEXP private, const char *passphrase)
 {
-  int i;
-  char *fname;
-  FILE *fp;
+  int rc;
   char *buf;
   size_t len;
   unsigned char grip[20];
-  char hexgrip[40+4+1];
   
   if ( !gcry_pk_get_keygrip (private, grip) )
     {
       log_error ("can't calculate keygrip\n");
       return seterr (General_Error);
     }
-  for (i=0; i < 20; i++)
-    sprintf (hexgrip+2*i, "%02X", grip[i]);
-  strcpy (hexgrip+40, ".key");
-
-  fname = make_filename (opt.homedir, "private-keys-v1.d", hexgrip, NULL);
-  if (!access (fname, F_OK))
-    {
-      log_error ("secret key file `%s' already exists - very strange\n",
-                 fname);
-      xfree (fname);
-      return seterr (General_Error);
-    }
-  fp = fopen (fname, "wbx");  /* FIXME: the x is a GNU extension - let
-                                 configure check whether this actually
-                                 works */
-  if (!fp) 
-    { 
-      log_error ("can't create `%s': %s\n", fname, strerror (errno));
-      xfree (fname);
-      return seterr (File_Create_Error);
-    }
 
   len = gcry_sexp_sprint (private, GCRYSEXP_FMT_CANON, NULL, 0);
   assert (len);
   buf = gcry_malloc_secure (len);
   if (!buf)
-    {
-      fclose (fp);
-      remove (fname);
-      xfree (fname);
       return seterr (Out_Of_Core);
-    }
   len = gcry_sexp_sprint (private, GCRYSEXP_FMT_CANON, buf, len);
   assert (len);
 
   if (passphrase)
     {
       unsigned char *p;
-      int rc;
 
       rc = agent_protect (buf, passphrase, &p, &len);
       if (rc)
         {
-          fclose (fp);
-          remove (fname);
-          xfree (fname);
           xfree (buf);
           return rc;
         }
@@ -100,27 +65,9 @@ store_key (GCRY_SEXP private, const char *passphrase)
       buf = p;
     }
 
-  if (fwrite (buf, len, 1, fp) != 1)
-    {
-      log_error ("error writing `%s': %s\n", fname, strerror (errno));
-      fclose (fp);
-      remove (fname);
-      xfree (fname);
-      xfree (buf);
-      return seterr (File_Create_Error);
-    }
-  if ( fclose (fp) )
-    {
-      log_error ("error closing `%s': %s\n", fname, strerror (errno));
-      remove (fname);
-      xfree (fname);
-      xfree (buf);
-      return seterr (File_Create_Error);
-    }
-
-  xfree (fname);
+  rc = agent_write_private_key (grip, buf, len, 0);
   xfree (buf);
-  return 0;
+  return rc;
 }
 
 
diff --git a/agent/learncard.c b/agent/learncard.c
new file mode 100644
index 000000000..4cd1cb848
--- /dev/null
+++ b/agent/learncard.c
@@ -0,0 +1,263 @@
+/* learncard.c - Handle the LEARN command
+ *	Copyright (C) 2002 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include <config.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <assert.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include "agent.h"
+#include "../assuan/assuan.h"
+
+struct keypair_info_s {
+  struct keypair_info_s *next;
+  int no_cert;
+  char *id;  /* points into grip */
+  char hexgrip[1];
+};
+typedef struct keypair_info_s *KEYPAIR_INFO;
+
+struct kpinfo_cb_parm_s {
+  int error;
+  KEYPAIR_INFO info;
+};
+
+
+static void
+release_keypair_info (KEYPAIR_INFO info)
+{
+  while (info)
+    {
+      KEYPAIR_INFO tmp = info->next;
+      xfree (info);
+      info = tmp;
+    }
+}
+
+
+
+/* This callback is used by agent_card_leanr and passed the content of
+   all KEYPAIRINFO lines.  It merely store this data away */
+static void
+kpinfo_cb (void *opaque, const char *line)
+{
+  struct kpinfo_cb_parm_s *parm = opaque;
+  KEYPAIR_INFO item;
+  char *p;
+
+  if (parm->error)
+    return; /* no need to gather data after an error coccured */
+  item = xtrycalloc (1, sizeof *item + strlen (line));
+  if (!item)
+    {
+      parm->error = GNUPG_Out_Of_Core;
+      return;
+    }
+  strcpy (item->hexgrip, line);
+  for (p = item->hexgrip; hexdigitp (p); p++)
+    ;
+  if (p == item->hexgrip && *p == 'X' && spacep (p+1))
+    {
+      item->no_cert = 1;
+      p++;
+    }
+  else if ((p - item->hexgrip) != 40 || !spacep (p))
+    { /* not a 20 byte hex keygrip or now followed by a space */
+      parm->error = GNUPG_Invalid_Response;
+      xfree (item);
+      return;
+    }
+  *p++ = 0;
+  while (spacep (p))
+    p++;
+  item->id = p;
+  for (; hexdigitp (p) || *p == '.'; p++)
+    ;
+  if (!(spacep (p) || !*p))
+    { /* invalid ID string */
+      parm->error = GNUPG_Invalid_Response;
+      xfree (item);
+      return;
+    }
+  *p = 0; /* ignore trailing stuff */
+  
+  /* store it */
+  item->next = parm->info;
+  parm->info = item;
+}
+
+
+/* Create an S-expression with the shadow info.  */
+static unsigned char *
+make_shadow_info (const char *serialno, const char *idstring)
+{
+  const char *s;
+  unsigned char *info, *p;
+  char numbuf[21];
+  int n;
+
+  for (s=serialno, n=0; *s && s[1]; s += 2)
+    n++;
+
+  info = p = xtrymalloc (1 + 21 + n
+                           + 21 + strlen (idstring) + 1 + 1);
+  *p++ = '(';
+  sprintf (numbuf, "%d:", n);
+  p = stpcpy (p, numbuf);
+  for (s=serialno; *s && s[1]; s += 2)
+    *p++ = xtoi_2 (s);
+  sprintf (numbuf, "%d:", strlen (idstring));
+  p = stpcpy (p, numbuf);
+  p = stpcpy (p, idstring);
+  *p++ = ')';
+  *p = 0;
+  return info;
+}
+
+
+/* Perform the learn operation.  If ASSUAN_CONTEXT is not NULL all new
+   certificates are send via Assuan */
+int
+agent_handle_learn (void *assuan_context)
+{
+  int rc;
+  struct kpinfo_cb_parm_s parm;
+  char *serialno = NULL;
+  KEYPAIR_INFO item;
+  unsigned char grip[20];
+  char *p;
+  int i;
+
+  memset (&parm, 0, sizeof parm);
+
+  /* Check whether a card is present and get the serial number */
+  rc = agent_card_serialno (&serialno);
+  if (rc)
+    goto leave;
+
+  /* now gather all the availabe info */
+  rc = agent_card_learn (kpinfo_cb, &parm);
+  if (!rc && parm.error)
+    rc = parm.error;
+  if (rc)
+    {
+      log_debug ("agent_card_learn failed: %s\n", gnupg_strerror (rc));
+      goto leave;
+    }
+
+  log_info ("card has S/N: %s\n", serialno);
+  for (item = parm.info; item; item = item->next)
+    {
+      unsigned char *pubkey, *shdkey;
+      size_t n;
+
+      if (opt.verbose)
+        log_info ("          id: %s    (grip=%s)\n", item->id, item->hexgrip);
+
+      if (item->no_cert)
+        continue; /* no public key yet available */
+
+      for (p=item->hexgrip, i=0; i < 20; p += 2, i++)
+        grip[i] = xtoi_2 (p);
+      
+      if (!agent_key_available (grip))
+        continue;
+      
+      /* unknown - store it */
+      rc = agent_card_readkey (item->id, &pubkey);
+      if (rc)
+        {
+          log_debug ("agent_card_readkey failed: %s\n", gnupg_strerror (rc));
+          goto leave;
+        }
+
+      {
+        unsigned char *shadow_info = make_shadow_info (serialno, item->id);
+        if (!shadow_info)
+          {
+            rc = GNUPG_Out_Of_Core;
+            xfree (pubkey);
+            goto leave;
+          }
+        rc = agent_shadow_key (pubkey, shadow_info, &shdkey);
+        xfree (shadow_info);
+      }
+      xfree (pubkey);
+      if (rc)
+        {
+          log_error ("shadowing the key failed: %s\n", gnupg_strerror (rc));
+          goto leave;
+        }
+      n = gcry_sexp_canon_len (shdkey, 0, NULL, NULL);
+      assert (n);
+
+      rc = agent_write_private_key (grip, shdkey, n, 0);
+      xfree (shdkey);
+      if (rc)
+        {
+          log_error ("error writing key: %s\n", gnupg_strerror (rc));
+          goto leave;
+        }
+
+      if (opt.verbose)
+        log_info ("stored\n");
+      
+      if (assuan_context)
+        {
+          char *derbuf;
+          size_t derbuflen;
+
+          rc = agent_card_readcert (item->id, &derbuf, &derbuflen);
+          if (rc)
+            {
+              log_error ("error reading certificate: %s\n",
+                         gnupg_strerror (rc));
+              goto leave;
+            }
+
+          rc = assuan_send_data (assuan_context, derbuf, derbuflen);
+          xfree (derbuf);
+          if (!rc)
+            rc = assuan_send_data (assuan_context, NULL, 0);
+          if (!rc)
+            rc = assuan_write_line (assuan_context, "END");
+          if (rc)
+            {
+              log_error ("sending certificate failed: %s\n",
+                         assuan_strerror (rc));
+              rc = map_assuan_err (rc);
+              goto leave;
+            }
+        }
+    }
+
+  
+ leave:
+  xfree (serialno);
+  release_keypair_info (parm.info);
+  return rc;
+}
+
+
diff --git a/agent/query.c b/agent/query.c
index 795e214e3..09aada0fd 100644
--- a/agent/query.c
+++ b/agent/query.c
@@ -110,6 +110,9 @@ getpin_cb (void *opaque, const void *buffer, size_t length)
 {
   struct entry_parm_s *parm = opaque;
 
+  if (!buffer)
+    return 0;
+
   /* we expect the pin to fit on one line */
   if (parm->lines || length >= parm->size)
     return ASSUAN_Too_Much_Data;