agent: Call TKDaemon READKEY command.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

agent/agent.h

@@ -748,8 +748,8 @@ int agent_tkd_pksign (ctrl_t ctrl,
                       const char *keygrip,
                       const unsigned char *indata, size_t indatalen,
                       unsigned char **r_buf, size_t *r_buflen);
-int agent_tkd_readkey (ctrl_t ctrl, const char *id,
-                       unsigned char **r_buf, char **r_keyref);
+int agent_tkd_readkey (ctrl_t ctrl, const char *keygrip,
+                       unsigned char **r_buf, size_t *r_buflen);
 
 /*-- learncard.c --*/
 int agent_handle_learn (ctrl_t ctrl, int send, void *assuan_context, int force);

agent/call-tkd.c

@@ -128,6 +128,52 @@ pin_cb (ctrl_t ctrl, const char *prompt, char **passphrase)
 			      hexgrip, CACHE_MODE_USER, NULL);
 }
 
+/* Read a key with KEYGRIP and return it in a malloced buffer pointed
+ * to by R_BUF as a valid S-expression.  If R_BUFLEN is not NULL the
+ * length is stored there. */
+int
+agent_tkd_readkey (ctrl_t ctrl, const char *keygrip,
+                   unsigned char **r_buf, size_t *r_buflen)
+{
+  int rc;
+  char line[ASSUAN_LINELENGTH];
+  membuf_t data;
+  size_t buflen;
+
+  *r_buf = NULL;
+  if (r_buflen)
+    *r_buflen = 0;
+
+  rc = start_tkd (ctrl);
+  if (rc)
+    return rc;
+
+  init_membuf (&data, 1024);
+  snprintf (line, DIM(line), "READKEY %s", keygrip);
+  rc = assuan_transact (daemon_ctx (ctrl), line,
+                        put_membuf_cb, &data,
+                        NULL, NULL, NULL, NULL);
+  if (rc)
+    {
+      xfree (get_membuf (&data, &buflen));
+      return unlock_tkd (ctrl, rc);
+    }
+  *r_buf = get_membuf (&data, &buflen);
+  if (!*r_buf)
+    return unlock_tkd (ctrl, gpg_error (GPG_ERR_ENOMEM));
+
+  if (!gcry_sexp_canon_len (*r_buf, buflen, NULL, NULL))
+    {
+      xfree (*r_buf); *r_buf = NULL;
+      return unlock_tkd (ctrl, gpg_error (GPG_ERR_INV_VALUE));
+    }
+  if (r_buflen)
+    *r_buflen = buflen;
+
+  return unlock_tkd (ctrl, 0);
+}
+
+
 int
 agent_tkd_pksign (ctrl_t ctrl, const char *keygrip,
                   const unsigned char *digest, size_t digestlen,
@@ -154,7 +200,7 @@ agent_tkd_pksign (ctrl_t ctrl, const char *keygrip,
   inqparm.extralen = digestlen;
   inqparm.pin = NULL;
 
-  snprintf(line, sizeof(line), "PKSIGN");
+  snprintf (line, sizeof(line), "PKSIGN %s", keygrip);
 
   rc = assuan_transact (daemon_ctx (ctrl), line,
 			put_membuf_cb, &data,

agent/command.c

@@ -1303,6 +1303,7 @@ cmd_keyattr (assuan_context_t ctx, char *line)
 static const char hlp_readkey[] =
   "READKEY [--no-data] [--format=ssh] <hexstring_with_keygrip>\n"
   "                    --card <keyid>\n"
+  "                    --token <hexstring_with_keygrip>\n"
   "\n"
   "Return the public key for the given keygrip or keyid.\n"
   "With --card, private key file with card information will be created.";
@@ -1315,13 +1316,14 @@ cmd_readkey (assuan_context_t ctx, char *line)
   gcry_sexp_t s_pkey = NULL;
   unsigned char *pkbuf = NULL;
   size_t pkbuflen;
-  int opt_card, opt_no_data, opt_format_ssh;
+  int opt_card, opt_token, opt_no_data, opt_format_ssh;
 
   if (ctrl->restricted)
     return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN));
 
   opt_no_data = has_option (line, "--no-data");
   opt_card = has_option (line, "--card");
+  opt_token = has_option (line, "--token");
   opt_format_ssh = has_option (line, "--format=ssh");
 
   line = skip_options (line);
@@ -1373,6 +1375,34 @@ cmd_readkey (assuan_context_t ctx, char *line)
       xfree (serialno);
       xfree (keyidbuf);
     }
+  else if (opt_token)
+    {
+      const char *keygrip = line;
+
+      rc = agent_tkd_readkey (ctrl, keygrip, &pkbuf, &pkbuflen);
+      if (rc)
+        goto leave;
+      rc = gcry_sexp_sscan (&s_pkey, NULL, (char*)pkbuf, pkbuflen);
+      if (rc)
+        goto leave;
+
+      if (!gcry_pk_get_keygrip (s_pkey, grip))
+        {
+          rc = gcry_pk_testkey (s_pkey);
+          if (rc == 0)
+            rc = gpg_error (GPG_ERR_INTERNAL);
+
+          goto leave;
+        }
+
+      if (agent_key_available (grip))
+        {
+          /* (Shadow)-key is not available in our key storage.  */
+          rc = agent_write_shadow_key (grip, NULL, NULL, pkbuf, 0);
+          if (rc)
+            goto leave;
+        }
+    }
   else
     {
       rc = parse_keygrip (ctx, line, grip);

agent/findkey.c

@@ -1821,16 +1821,22 @@ agent_write_shadow_key (const unsigned char *grip,
   unsigned char *shdkey;
   size_t len;
 
-  /* Just in case some caller did not parse the stuff correctly, skip
-   * leading spaces.  */
-  while (spacep (serialno))
-    serialno++;
-  while (spacep (keyid))
-    keyid++;
+  if (serialno == NULL && keyid == NULL)
+    /* It's a token, identified by the keygrip.  */
+    shadow_info = NULL;
+  else
+    {
+      /* Just in case some caller did not parse the stuff correctly, skip
+       * leading spaces.  */
+      while (spacep (serialno))
+        serialno++;
+      while (spacep (keyid))
+        keyid++;
 
-  shadow_info = make_shadow_info (serialno, keyid);
-  if (!shadow_info)
-    return gpg_error_from_syserror ();
+      shadow_info = make_shadow_info (serialno, keyid);
+      if (!shadow_info)
+        return gpg_error_from_syserror ();
+    }
 
   err = agent_shadow_key (pkbuf, shadow_info, &shdkey);
   xfree (shadow_info);

agent/keyformat.txt

@@ -342,9 +342,11 @@ to keys stored on a token:
    (comment whatever)
 )
 
-The currently used protocols are "t1-v1" (token info version 1) and
-"tpm2-v1" (TPM format key information).  The second list with the
-information has this layout for "t1-v1":
+The currently used protocols are "t1-v1" (token info version 1),
+"tpm2-v1" (TPM format key information), and "tkd-v1" (token daemon
+info version 1).
+
+The second list with the information has this layout for "t1-v1":
 
 (card_serial_number id_string_of_key fixed_pin_length)
 
@@ -353,13 +355,15 @@ the PIN; a value of 0 indicates that this information is not
 available.  The rationale for this field is that some pinpad equipped
 readers don't allow passing a variable length PIN.
 
-This is the (info) layout for "tpm2-v1":
+For "tpm2-v1", the layout of the (info) is:
 
 (parent tpm_private_string tpm_public_string)
 
 Although this precise format is encapsulated inside the tpm2daemon
 itself and nothing in gpg ever uses this.
 
+For "tkd-v1", the layout of the (info) part is nothing.
+
 More items may be added to the list.
 
 ** OpenPGP Private Key Transfer Format

agent/protect.c

@@ -1545,10 +1545,15 @@ agent_shadow_key_type (const unsigned char *pubkey,
   int depth = 0;
   char *p;
   size_t pubkey_len = gcry_sexp_canon_len (pubkey, 0, NULL,NULL);
-  size_t shadow_info_len = gcry_sexp_canon_len (shadow_info, 0, NULL,NULL);
+  size_t shadow_info_len;
 
-  if (!pubkey_len || !shadow_info_len)
+  if (!pubkey_len)
     return gpg_error (GPG_ERR_INV_VALUE);
+  if (shadow_info)
+    shadow_info_len = gcry_sexp_canon_len (shadow_info, 0, NULL,NULL);
+  else
+    shadow_info_len = 0;
+
   s = pubkey;
   if (*s != '(')
     return gpg_error (GPG_ERR_INV_SEXP);
@@ -1604,7 +1609,8 @@ agent_shadow_key_type (const unsigned char *pubkey,
   memcpy (p, pubkey+14, point - (pubkey+14));
   p += point - (pubkey+14);
   p += sprintf (p, "(8:shadowed%d:%s", (int)strlen(type), type);
-  memcpy (p, shadow_info, shadow_info_len);
+  if (shadow_info_len)
+    memcpy (p, shadow_info, shadow_info_len);
   p += shadow_info_len;
   *p++ = ')';
   memcpy (p, point, pubkey_len - (point - pubkey));
@@ -1618,7 +1624,10 @@ agent_shadow_key (const unsigned char *pubkey,
                   const unsigned char *shadow_info,
                   unsigned char **result)
 {
-  return agent_shadow_key_type (pubkey, shadow_info, "t1-v1", result);
+  if (shadow_info)
+    return agent_shadow_key_type (pubkey, shadow_info, "t1-v1", result);
+  else
+    return agent_shadow_key_type (pubkey, NULL, "tkd-v1", result);
 }
 
 /* Parse a canonical encoded shadowed key and return a pointer to the