From 905b6a36d3ca21b2f619721e1de892398e5eb759 Mon Sep 17 00:00:00 2001
From: Werner Koch <wk@gnupg.org>
Date: Tue, 6 Nov 2012 12:02:25 +0100
Subject: [PATCH] Allow decryption with card keys > 3072 bits

* scd/command.c (MAXLEN_SETDATA): New.
(cmd_setdata): Add option --append.
* agent/call-scd.c (agent_card_pkdecrypt): Use new option for long
data.

* scd/app-openpgp.c (struct app_local_s): Add field manufacturer.
(app_select_openpgp): Store manufacturer.
(do_decipher): Print a note for broken cards.

--

Please note that I was not able to run a full test because I only have
broken cards (S/N < 346) available.
---
 agent/call-scd.c  | 25 +++++++++++++++----------
 scd/app-openpgp.c | 10 ++++++++++
 scd/command.c     | 40 +++++++++++++++++++++++++++++++++-------
 3 files changed, 58 insertions(+), 17 deletions(-)

diff --git a/agent/call-scd.c b/agent/call-scd.c
index 8fc00542e..2bda3779d 100644
--- a/agent/call-scd.c
+++ b/agent/call-scd.c
@@ -926,17 +926,22 @@ agent_card_pkdecrypt (ctrl_t ctrl,
     return rc;
 
   /* FIXME: use secure memory where appropriate */
-  if (indatalen*2 + 50 > DIM(line))
-    return unlock_scd (ctrl, gpg_error (GPG_ERR_GENERAL));
 
-  sprintf (line, "SETDATA ");
-  p = line + strlen (line);
-  for (i=0; i < indatalen ; i++, p += 2 )
-    sprintf (p, "%02X", indata[i]);
-  rc = assuan_transact (ctrl->scd_local->ctx, line,
-                        NULL, NULL, NULL, NULL, NULL, NULL);
-  if (rc)
-    return unlock_scd (ctrl, rc);
+  for (len = 0; len < indatalen;)
+    {
+      p = stpcpy (line, "SETDATA ");
+      if (len)
+        p = stpcpy (p, "--append ");
+      for (i=0; len < indatalen && (i*2 < DIM(line)-50); i++, len++)
+        {
+          sprintf (p, "%02X", indata[len]);
+          p += 2;
+        }
+      rc = assuan_transact (ctrl->scd_local->ctx, line,
+                            NULL, NULL, NULL, NULL, NULL, NULL);
+      if (rc)
+        return unlock_scd (ctrl, rc);
+    }
 
   init_membuf (&data, 1024);
   inqparm.ctx = ctrl->scd_local->ctx;
diff --git a/scd/app-openpgp.c b/scd/app-openpgp.c
index 9c8ef59cb..5a9214c1c 100644
--- a/scd/app-openpgp.c
+++ b/scd/app-openpgp.c
@@ -158,6 +158,8 @@ struct app_local_s {
 
   unsigned char status_indicator; /* The card status indicator.  */
 
+  unsigned int manufacturer:16;   /* Manufacturer ID from the s/n.  */
+
   /* Keep track of the ISO card capabilities.  */
   struct
   {
@@ -3474,6 +3476,12 @@ do_decipher (app_t app, const char *keyidstr,
                              indata, indatalen, le_value, padind,
                              outdata, outdatalen);
       xfree (fixbuf);
+
+      if (gpg_err_code (rc) == GPG_ERR_CARD /* actual SW is 0x640a */
+          && app->app_local->manufacturer == 5
+          && app->card_version == 0x0200)
+        log_info ("NOTE: Cards with manufacturer id 5 and s/n <= 346 (0x15a)"
+                  " do not work with encryption keys > 2048 bits\n");
     }
 
   return rc;
@@ -3761,6 +3769,8 @@ app_select_openpgp (app_t app)
           goto leave;
         }
 
+      app->app_local->manufacturer = manufacturer;
+
       if (app->card_version >= 0x0200)
         app->app_local->extcap.is_v2 = 1;
 
diff --git a/scd/command.c b/scd/command.c
index 102715804..17da5b7ae 100644
--- a/scd/command.c
+++ b/scd/command.c
@@ -48,6 +48,9 @@
 /* Maximum allowed size of key data as used in inquiries. */
 #define MAXLEN_KEYDATA 4096
 
+/* Maximum allowed total data size for SETDATA.  */
+#define MAXLEN_SETDATA 4096
+
 /* Maximum allowed size of certificate data as used in inquiries. */
 #define MAXLEN_CERTDATA 16384
 
@@ -848,17 +851,24 @@ cmd_readkey (assuan_context_t ctx, char *line)
 
 
 static const char hlp_setdata[] =
-  "SETDATA <hexstring> \n"
+  "SETDATA [--append] <hexstring>\n"
   "\n"
-  "The client should use this command to tell us the data he want to sign.";
+  "The client should use this command to tell us the data he want to sign.\n"
+  "With the option --append, the data is appended to the data set by a\n"
+  "previous SETDATA command.";
 static gpg_error_t
 cmd_setdata (assuan_context_t ctx, char *line)
 {
   ctrl_t ctrl = assuan_get_pointer (ctx);
-  int n;
+  int append;
+  int n, i, off;
   char *p;
   unsigned char *buf;
 
+  append = (ctrl->in_data.value && has_option (line, "--append"));
+
+  line = skip_options (line);
+
   if (locked_session && locked_session != ctrl->server_local)
     return gpg_error (GPG_ERR_LOCKED);
 
@@ -872,15 +882,31 @@ cmd_setdata (assuan_context_t ctx, char *line)
   if ((n&1))
     return set_error (GPG_ERR_ASS_PARAMETER, "odd number of digits");
   n /= 2;
-  buf = xtrymalloc (n);
+  if (append)
+    {
+      if (ctrl->in_data.valuelen + n > MAXLEN_SETDATA)
+        return set_error (GPG_ERR_TOO_LARGE,
+                          "limit on total size of data reached");
+      buf = xtrymalloc (ctrl->in_data.valuelen + n);
+    }
+  else
+    buf = xtrymalloc (n);
   if (!buf)
     return out_of_core ();
 
+  if (append)
+    {
+      memcpy (buf, ctrl->in_data.value, ctrl->in_data.valuelen);
+      off = ctrl->in_data.valuelen;
+    }
+  else
+    off = 0;
+  for (p=line, i=0; i < n; p += 2, i++)
+    buf[off+i] = xtoi_2 (p);
+
   xfree (ctrl->in_data.value);
   ctrl->in_data.value = buf;
-  ctrl->in_data.valuelen = n;
-  for (p=line, n=0; n < ctrl->in_data.valuelen; p += 2, n++)
-    buf[n] = xtoi_2 (p);
+  ctrl->in_data.valuelen = off+n;
   return 0;
 }