Adding upstream version 2.2.40.upstream/2.2.40upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3048 insertions, 0 deletions

diff --git a/sm/minip12.c b/sm/minip12.c
new file mode 100644
index 0000000..29b4898
--- /dev/null
+++ b/sm/minip12.c
@@ -0,0 +1,3048 @@
+/* minip12.c - A minimal pkcs-12 implementation.
+ * Copyright (C) 2002, 2003, 2004, 2006, 2011 Free Software Foundation, Inc.
+ * Copyright (C) 2014 Werner Koch
+ * Copyright (C) 2022 g10 Code GmbH
+ *
+ * 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 3 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, see <https://www.gnu.org/licenses/>.
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+/* References:
+ * RFC-7292 - PKCS #12: Personal Information Exchange Syntax v1.1
+ * RFC-8351 - The PKCS #8 EncryptedPrivateKeyInfo Media Type
+ * RFC-5958 - Asymmetric Key Packages
+ * RFC-3447 - PKCS  #1: RSA Cryptography Specifications Version 2.1
+ * RFC-5915 - Elliptic Curve Private Key Structure
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <gcrypt.h>
+#include <errno.h>
+
+#include <ksba.h>
+
+#include "../common/util.h"
+#include "../common/logging.h"
+#include "../common/utf8conv.h"
+#include "../common/tlv.h"
+#include "../common/openpgpdefs.h" /* Only for openpgp_curve_to_oid.  */
+#include "minip12.h"
+
+#ifndef DIM
+#define DIM(v)		     (sizeof(v)/sizeof((v)[0]))
+#endif
+
+
+
+static unsigned char const oid_data[9] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x07, 0x01 };
+static unsigned char const oid_encryptedData[9] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x07, 0x06 };
+static unsigned char const oid_pkcs_12_keyBag[11] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x0C, 0x0A, 0x01, 0x01 };
+static unsigned char const oid_pkcs_12_pkcs_8ShroudedKeyBag[11] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x0C, 0x0A, 0x01, 0x02 };
+static unsigned char const oid_pkcs_12_CertBag[11] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x0C, 0x0A, 0x01, 0x03 };
+static unsigned char const oid_pkcs_12_CrlBag[11] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x0C, 0x0A, 0x01, 0x04 };
+
+static unsigned char const oid_pbeWithSHAAnd3_KeyTripleDES_CBC[10] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x0C, 0x01, 0x03 };
+static unsigned char const oid_pbeWithSHAAnd40BitRC2_CBC[10] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x0C, 0x01, 0x06 };
+static unsigned char const oid_x509Certificate_for_pkcs_12[10] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x09, 0x16, 0x01 };
+
+static unsigned char const oid_pkcs5PBKDF2[9] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x05, 0x0C };
+static unsigned char const oid_pkcs5PBES2[9] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x05, 0x0D };
+static unsigned char const oid_aes128_CBC[9] = {
+  0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x01, 0x02 };
+
+static unsigned char const oid_rsaEncryption[9] = {
+  0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01 };
+static unsigned char const oid_pcPublicKey[7] = {
+  0x2A, 0x86, 0x48, 0xCE, 0x3D, 0x02, 0x01 };
+
+static unsigned char const data_3desiter2048[30] = {
+  0x30, 0x1C, 0x06, 0x0A, 0x2A, 0x86, 0x48, 0x86,
+  0xF7, 0x0D, 0x01, 0x0C, 0x01, 0x03, 0x30, 0x0E,
+  0x04, 0x08, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+  0xFF, 0xFF, 0x02, 0x02, 0x08, 0x00 };
+#define DATA_3DESITER2048_SALT_OFF  18
+
+static unsigned char const data_rc2iter2048[30] = {
+  0x30, 0x1C, 0x06, 0x0A, 0x2A, 0x86, 0x48, 0x86,
+  0xF7, 0x0D, 0x01, 0x0C, 0x01, 0x06, 0x30, 0x0E,
+  0x04, 0x08, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+  0xFF, 0xFF, 0x02, 0x02, 0x08, 0x00 };
+#define DATA_RC2ITER2048_SALT_OFF  18
+
+static unsigned char const data_mactemplate[51] = {
+  0x30, 0x31, 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
+  0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05, 0x00, 0x04,
+  0x14, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0x04, 0x08, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x02,
+  0x02, 0x08, 0x00 };
+#define DATA_MACTEMPLATE_MAC_OFF 17
+#define DATA_MACTEMPLATE_SALT_OFF 39
+
+static unsigned char const data_attrtemplate[106] = {
+  0x31, 0x7c, 0x30, 0x55, 0x06, 0x09, 0x2a, 0x86,
+  0x48, 0x86, 0xf7, 0x0d, 0x01, 0x09, 0x14, 0x31,
+  0x48, 0x1e, 0x46, 0x00, 0x47, 0x00, 0x6e, 0x00,
+  0x75, 0x00, 0x50, 0x00, 0x47, 0x00, 0x20, 0x00,
+  0x65, 0x00, 0x78, 0x00, 0x70, 0x00, 0x6f, 0x00,
+  0x72, 0x00, 0x74, 0x00, 0x65, 0x00, 0x64, 0x00,
+  0x20, 0x00, 0x63, 0x00, 0x65, 0x00, 0x72, 0x00,
+  0x74, 0x00, 0x69, 0x00, 0x66, 0x00, 0x69, 0x00,
+  0x63, 0x00, 0x61, 0x00, 0x74, 0x00, 0x65, 0x00,
+  0x20, 0x00, 0x66, 0x00, 0x66, 0x00, 0x66, 0x00,
+  0x66, 0x00, 0x66, 0x00, 0x66, 0x00, 0x66, 0x00,
+  0x66, 0x30, 0x23, 0x06, 0x09, 0x2a, 0x86, 0x48,
+  0x86, 0xf7, 0x0d, 0x01, 0x09, 0x15, 0x31, 0x16,
+  0x04, 0x14 }; /* Need to append SHA-1 digest. */
+#define DATA_ATTRTEMPLATE_KEYID_OFF 73
+
+struct buffer_s
+{
+  unsigned char *buffer;
+  size_t length;
+};
+
+
+struct tag_info
+{
+  int class;
+  int is_constructed;
+  unsigned long tag;
+  unsigned long length;  /* length part of the TLV */
+  int nhdr;
+  int ndef;              /* It is an indefinite length */
+};
+
+/* Parser communication object.  */
+struct p12_parse_ctx_s
+{
+  /* The callback for parsed certificates and its arg.  */
+  void (*certcb)(void*, const unsigned char*, size_t);
+  void *certcbarg;
+
+  /* The supplied parseword.  */
+  const char *password;
+
+  /* Set to true if the password was wrong.  */
+  int badpass;
+
+  /* Malloced name of the curve.  */
+  char *curve;
+
+  /* The private key as an MPI array.   */
+  gcry_mpi_t *privatekey;
+};
+
+
+static int opt_verbose;
+
+
+void
+p12_set_verbosity (int verbose)
+{
+  opt_verbose = verbose;
+}
+
+
+/* static void */
+/* dump_tag_info (struct tag_info *ti) */
+/* { */
+/*   log_debug ("p12_parse: ti.class=%d tag=%lu len=%lu nhdr=%d %s%s\n", */
+/*              ti->class, ti->tag, ti->length, ti->nhdr, */
+/*              ti->is_constructed?" cons":"", */
+/*              ti->ndef?" ndef":""); */
+/* } */
+
+
+/* Wrapper around tlv_builder_add_ptr to add an OID.  When we
+ * eventually put the whole tlv_builder stuff into Libksba, we can add
+ * such a function there.  Right now we don't do this to avoid a
+ * dependency on Libksba.  Function return 1 on error.  */
+static int
+builder_add_oid (tlv_builder_t tb, int class, const char *oid)
+{
+  gpg_error_t err;
+  unsigned char *der;
+  size_t derlen;
+
+  err = ksba_oid_from_str (oid, &der, &derlen);
+  if (err)
+    {
+      log_error ("%s: error converting '%s' to DER: %s\n",
+                 __func__, oid, gpg_strerror (err));
+      return 1;
+    }
+
+  tlv_builder_add_val (tb, class, TAG_OBJECT_ID, der, derlen);
+  ksba_free (der);
+  return 0;
+}
+
+
+/* Wrapper around tlv_builder_add_ptr to add an MPI.  TAG may either
+ * be OCTET_STRING or BIT_STRING.  When we eventually put the whole
+ * tlv_builder stuff into Libksba, we can add such a function there.
+ * Right now we don't do this to avoid a dependency on Libksba.
+ * Function return 1 on error.  STRIP is a hack to remove the first
+ * octet from the value. */
+static int
+builder_add_mpi (tlv_builder_t tb, int class, int tag, gcry_mpi_t mpi,
+                 int strip)
+{
+  int returncode;
+  gpg_error_t err;
+  const unsigned char *s;
+  unsigned char *freethis = NULL;
+  unsigned char *freethis2 = NULL;
+  unsigned int nbits;
+  size_t n;
+
+  if (gcry_mpi_get_flag (mpi, GCRYMPI_FLAG_OPAQUE))
+    {
+      s = gcry_mpi_get_opaque (mpi, &nbits);
+      n = (nbits+7)/8;
+    }
+  else
+    {
+      err = gcry_mpi_aprint (GCRYMPI_FMT_USG, &freethis, &n, mpi);
+      if (err)
+        {
+          log_error ("%s: error converting MPI: %s\n",
+                     __func__, gpg_strerror (err));
+          returncode = 1;
+          goto leave;
+        }
+      s = freethis;
+    }
+
+  if (tag == TAG_BIT_STRING)
+    {
+      freethis2 = xtrymalloc_secure (n + 1);
+      if (!freethis2)
+        {
+          err = gpg_error_from_syserror ();
+          log_error ("%s: error converting MPI: %s\n",
+                     __func__, gpg_strerror (err));
+          returncode = 1;
+          goto leave;
+        }
+      freethis2[0] = 0;
+      memcpy (freethis2+1, s, n);
+      s = freethis2;
+      n++;
+    }
+
+  strip = !!strip;
+  if (strip && n < 2)
+    strip = 0;
+
+  tlv_builder_add_val (tb, class, tag, s+strip, n-strip);
+  returncode = 0;
+
+ leave:
+  xfree (freethis);
+  xfree (freethis2);
+  return returncode;
+}
+
+
+/* Parse the buffer at the address BUFFER which is of SIZE and return
+   the tag and the length part from the TLV triplet.  Update BUFFER
+   and SIZE on success.  Checks that the encoded length does not
+   exhaust the length of the provided buffer. */
+static int
+parse_tag (unsigned char const **buffer, size_t *size, struct tag_info *ti)
+{
+  int c;
+  unsigned long tag;
+  const unsigned char *buf = *buffer;
+  size_t length = *size;
+
+  ti->length = 0;
+  ti->ndef = 0;
+  ti->nhdr = 0;
+
+  /* Get the tag */
+  if (!length)
+    return -1; /* premature eof */
+  c = *buf++; length--;
+  ti->nhdr++;
+
+  ti->class = (c & 0xc0) >> 6;
+  ti->is_constructed = !!(c & 0x20);
+  tag = c & 0x1f;
+
+  if (tag == 0x1f)
+    {
+      tag = 0;
+      do
+        {
+          tag <<= 7;
+          if (!length)
+            return -1; /* premature eof */
+          c = *buf++; length--;
+          ti->nhdr++;
+          tag |= c & 0x7f;
+        }
+      while (c & 0x80);
+    }
+  ti->tag = tag;
+
+  /* Get the length */
+  if (!length)
+    return -1; /* prematureeof */
+  c = *buf++; length--;
+  ti->nhdr++;
+
+  if ( !(c & 0x80) )
+    ti->length = c;
+  else if (c == 0x80)
+    ti->ndef = 1;
+  else if (c == 0xff)
+    return -1; /* forbidden length value */
+  else
+    {
+      unsigned long len = 0;
+      int count = c & 0x7f;
+
+      for (; count; count--)
+        {
+          len <<= 8;
+          if (!length)
+            return -1; /* premature_eof */
+          c = *buf++; length--;
+          ti->nhdr++;
+          len |= c & 0xff;
+        }
+      ti->length = len;
+    }
+
+  if (ti->class == CLASS_UNIVERSAL && !ti->tag)
+    ti->length = 0;
+
+  if (ti->length > length)
+    return -1; /* data larger than buffer. */
+
+  *buffer = buf;
+  *size = length;
+  return 0;
+}
+
+
+/* Given an ASN.1 chunk of a structure like:
+
+     24 NDEF:       OCTET STRING  -- This is not passed to us
+     04    1:         OCTET STRING  -- INPUT point s to here
+            :           30
+     04    1:         OCTET STRING
+            :           80
+          [...]
+     04    2:         OCTET STRING
+            :           00 00
+            :         } -- This denotes a Null tag and are the last
+                        -- two bytes in INPUT.
+
+   Create a new buffer with the content of that octet string.  INPUT
+   is the original buffer with a length as stored at LENGTH.  Returns
+   NULL on error or a new malloced buffer with the length of this new
+   buffer stored at LENGTH and the number of bytes parsed from input
+   are added to the value stored at INPUT_CONSUMED.  INPUT_CONSUMED is
+   allowed to be passed as NULL if the caller is not interested in
+   this value. */
+static unsigned char *
+cram_octet_string (const unsigned char *input, size_t *length,
+                   size_t *input_consumed)
+{
+  const unsigned char *s = input;
+  size_t n = *length;
+  unsigned char *output, *d;
+  struct tag_info ti;
+
+  /* Allocate output buf.  We know that it won't be longer than the
+     input buffer. */
+  d = output = gcry_malloc (n);
+  if (!output)
+    goto bailout;
+
+  while (n)
+    {
+      if (parse_tag (&s, &n, &ti))
+        goto bailout;
+      if (ti.class == CLASS_UNIVERSAL && ti.tag == TAG_OCTET_STRING
+          && !ti.ndef && !ti.is_constructed)
+        {
+          memcpy (d, s, ti.length);
+          s += ti.length;
+          d += ti.length;
+          n -= ti.length;
+        }
+      else if (ti.class == CLASS_UNIVERSAL && !ti.tag && !ti.is_constructed)
+        break; /* Ready */
+      else
+        goto bailout;
+    }
+
+
+  *length = d - output;
+  if (input_consumed)
+    *input_consumed += s - input;
+  return output;
+
+ bailout:
+  if (input_consumed)
+    *input_consumed += s - input;
+  gcry_free (output);
+  return NULL;
+}
+
+
+
+static int
+string_to_key (int id, char *salt, size_t saltlen, int iter, const char *pw,
+               int req_keylen, unsigned char *keybuf)
+{
+  int rc, i, j;
+  gcry_md_hd_t md;
+  gcry_mpi_t num_b1 = NULL;
+  int pwlen;
+  unsigned char hash[20], buf_b[64], buf_i[128], *p;
+  size_t cur_keylen;
+  size_t n;
+
+  cur_keylen = 0;
+  pwlen = strlen (pw);
+  if (pwlen > 63/2)
+    {
+      log_error ("password too long\n");
+      return -1;
+    }
+
+  if (saltlen < 8)
+    {
+      log_error ("salt too short\n");
+      return -1;
+    }
+
+  /* Store salt and password in BUF_I */
+  p = buf_i;
+  for(i=0; i < 64; i++)
+    *p++ = salt [i%saltlen];
+  for(i=j=0; i < 64; i += 2)
+    {
+      *p++ = 0;
+      *p++ = pw[j];
+      if (++j > pwlen) /* Note, that we include the trailing zero */
+        j = 0;
+    }
+
+  for (;;)
+    {
+      rc = gcry_md_open (&md, GCRY_MD_SHA1, 0);
+      if (rc)
+        {
+          log_error ( "gcry_md_open failed: %s\n", gpg_strerror (rc));
+          return rc;
+        }
+      for(i=0; i < 64; i++)
+        gcry_md_putc (md, id);
+      gcry_md_write (md, buf_i, 128);
+      memcpy (hash, gcry_md_read (md, 0), 20);
+      gcry_md_close (md);
+      for (i=1; i < iter; i++)
+        gcry_md_hash_buffer (GCRY_MD_SHA1, hash, hash, 20);
+
+      for (i=0; i < 20 && cur_keylen < req_keylen; i++)
+        keybuf[cur_keylen++] = hash[i];
+      if (cur_keylen == req_keylen)
+        {
+          gcry_mpi_release (num_b1);
+          return 0; /* ready */
+        }
+
+      /* need more bytes. */
+      for(i=0; i < 64; i++)
+        buf_b[i] = hash[i % 20];
+      rc = gcry_mpi_scan (&num_b1, GCRYMPI_FMT_USG, buf_b, 64, &n);
+      if (rc)
+        {
+          log_error ( "gcry_mpi_scan failed: %s\n", gpg_strerror (rc));
+          return -1;
+        }
+      gcry_mpi_add_ui (num_b1, num_b1, 1);
+      for (i=0; i < 128; i += 64)
+        {
+          gcry_mpi_t num_ij;
+
+          rc = gcry_mpi_scan (&num_ij, GCRYMPI_FMT_USG, buf_i + i, 64, &n);
+          if (rc)
+            {
+              log_error ( "gcry_mpi_scan failed: %s\n",
+                       gpg_strerror (rc));
+              return -1;
+            }
+          gcry_mpi_add (num_ij, num_ij, num_b1);
+          gcry_mpi_clear_highbit (num_ij, 64*8);
+          rc = gcry_mpi_print (GCRYMPI_FMT_USG, buf_i + i, 64, &n, num_ij);
+          if (rc)
+            {
+              log_error ( "gcry_mpi_print failed: %s\n",
+                          gpg_strerror (rc));
+              return -1;
+            }
+          gcry_mpi_release (num_ij);
+        }
+    }
+}
+
+
+static int
+set_key_iv (gcry_cipher_hd_t chd, char *salt, size_t saltlen, int iter,
+            const char *pw, int keybytes)
+{
+  unsigned char keybuf[24];
+  int rc;
+
+  log_assert (keybytes == 5 || keybytes == 24);
+  if (string_to_key (1, salt, saltlen, iter, pw, keybytes, keybuf))
+    return -1;
+  rc = gcry_cipher_setkey (chd, keybuf, keybytes);
+  if (rc)
+    {
+      log_error ( "gcry_cipher_setkey failed: %s\n", gpg_strerror (rc));
+      return -1;
+    }
+
+  if (string_to_key (2, salt, saltlen, iter, pw, 8, keybuf))
+    return -1;
+  rc = gcry_cipher_setiv (chd, keybuf, 8);
+  if (rc)
+    {
+      log_error ("gcry_cipher_setiv failed: %s\n", gpg_strerror (rc));
+      return -1;
+    }
+  return 0;
+}
+
+
+static int
+set_key_iv_pbes2 (gcry_cipher_hd_t chd, char *salt, size_t saltlen, int iter,
+                  const void *iv, size_t ivlen, const char *pw, int algo)
+{
+  unsigned char *keybuf;
+  size_t keylen;
+  int rc;
+
+  keylen = gcry_cipher_get_algo_keylen (algo);
+  if (!keylen)
+    return -1;
+  keybuf = gcry_malloc_secure (keylen);
+  if (!keybuf)
+    return -1;
+
+  rc = gcry_kdf_derive (pw, strlen (pw),
+                        GCRY_KDF_PBKDF2, GCRY_MD_SHA1,
+                        salt, saltlen, iter, keylen, keybuf);
+  if (rc)
+    {
+      log_error ("gcry_kdf_derive failed: %s\n", gpg_strerror (rc));
+      gcry_free (keybuf);
+      return -1;
+    }
+
+  rc = gcry_cipher_setkey (chd, keybuf, keylen);
+  gcry_free (keybuf);
+  if (rc)
+    {
+      log_error ("gcry_cipher_setkey failed: %s\n", gpg_strerror (rc));
+      return -1;
+    }
+
+
+  rc = gcry_cipher_setiv (chd, iv, ivlen);
+  if (rc)
+    {
+      log_error ("gcry_cipher_setiv failed: %s\n", gpg_strerror (rc));
+      return -1;
+    }
+  return 0;
+}
+
+
+static void
+crypt_block (unsigned char *buffer, size_t length, char *salt, size_t saltlen,
+             int iter, const void *iv, size_t ivlen,
+             const char *pw, int cipher_algo, int encrypt)
+{
+  gcry_cipher_hd_t chd;
+  int rc;
+
+  rc = gcry_cipher_open (&chd, cipher_algo, GCRY_CIPHER_MODE_CBC, 0);
+  if (rc)
+    {
+      log_error ( "gcry_cipher_open failed: %s\n", gpg_strerror(rc));
+      wipememory (buffer, length);
+      return;
+    }
+
+  if (cipher_algo == GCRY_CIPHER_AES128
+      ? set_key_iv_pbes2 (chd, salt, saltlen, iter, iv, ivlen, pw, cipher_algo)
+      : set_key_iv (chd, salt, saltlen, iter, pw,
+                    cipher_algo == GCRY_CIPHER_RFC2268_40? 5:24))
+    {
+      wipememory (buffer, length);
+      goto leave;
+    }
+
+  rc = encrypt? gcry_cipher_encrypt (chd, buffer, length, NULL, 0)
+              : gcry_cipher_decrypt (chd, buffer, length, NULL, 0);
+
+  if (rc)
+    {
+      wipememory (buffer, length);
+      log_error ("%scrytion failed (%zu bytes): %s\n",
+                 encrypt?"en":"de", length, gpg_strerror (rc));
+      goto leave;
+    }
+
+ leave:
+  gcry_cipher_close (chd);
+}
+
+
+/* Decrypt a block of data and try several encodings of the key.
+   CIPHERTEXT is the encrypted data of size LENGTH bytes; PLAINTEXT is
+   a buffer of the same size to receive the decryption result. SALT,
+   SALTLEN, ITER and PW are the information required for decryption
+   and CIPHER_ALGO is the algorithm id to use.  CHECK_FNC is a
+   function called with the plaintext and used to check whether the
+   decryption succeeded; i.e. that a correct passphrase has been
+   given.  That function shall return true if the decryption has likely
+   succeeded. */
+static void
+decrypt_block (const void *ciphertext, unsigned char *plaintext, size_t length,
+               char *salt, size_t saltlen,
+               int iter, const void *iv, size_t ivlen,
+               const char *pw, int cipher_algo,
+               int (*check_fnc) (const void *, size_t))
+{
+  static const char * const charsets[] = {
+    "",   /* No conversion - use the UTF-8 passphrase direct.  */
+    "ISO-8859-1",
+    "ISO-8859-15",
+    "ISO-8859-2",
+    "ISO-8859-3",
+    "ISO-8859-4",
+    "ISO-8859-5",
+    "ISO-8859-6",
+    "ISO-8859-7",
+    "ISO-8859-8",
+    "ISO-8859-9",
+    "KOI8-R",
+    "IBM437",
+    "IBM850",
+    "EUC-JP",
+    "BIG5",
+    NULL
+  };
+  int charsetidx = 0;
+  char *convertedpw = NULL;   /* Malloced and converted password or NULL.  */
+  size_t convertedpwsize = 0; /* Allocated length.  */
+
+  for (charsetidx=0; charsets[charsetidx]; charsetidx++)
+    {
+      if (*charsets[charsetidx])
+        {
+          jnlib_iconv_t cd;
+          const char *inptr;
+          char *outptr;
+          size_t inbytes, outbytes;
+
+          if (!convertedpw)
+            {
+              /* We assume one byte encodings.  Thus we can allocate
+                 the buffer of the same size as the original
+                 passphrase; the result will actually be shorter
+                 then.  */
+              convertedpwsize = strlen (pw) + 1;
+              convertedpw = gcry_malloc_secure (convertedpwsize);
+              if (!convertedpw)
+                {
+                  log_info ("out of secure memory while"
+                            " converting passphrase\n");
+                  break; /* Give up.  */
+                }
+            }
+
+          cd = jnlib_iconv_open (charsets[charsetidx], "utf-8");
+          if (cd == (jnlib_iconv_t)(-1))
+            continue;
+
+          inptr = pw;
+          inbytes = strlen (pw);
+          outptr = convertedpw;
+          outbytes = convertedpwsize - 1;
+          if ( jnlib_iconv (cd, (const char **)&inptr, &inbytes,
+                      &outptr, &outbytes) == (size_t)-1)
+            {
+              jnlib_iconv_close (cd);
+              continue;
+            }
+          *outptr = 0;
+          jnlib_iconv_close (cd);
+          log_info ("decryption failed; trying charset '%s'\n",
+                    charsets[charsetidx]);
+        }
+      memcpy (plaintext, ciphertext, length);
+      crypt_block (plaintext, length, salt, saltlen, iter, iv, ivlen,
+                   convertedpw? convertedpw:pw, cipher_algo, 0);
+      if (check_fnc (plaintext, length))
+        break; /* Decryption succeeded. */
+    }
+  gcry_free (convertedpw);
+}
+
+
+/* Return true if the decryption of an bag_encrypted_data object has
+   likely succeeded.  */
+static int
+bag_decrypted_data_p (const void *plaintext, size_t length)
+{
+  struct tag_info ti;
+  const unsigned char *p = plaintext;
+  size_t n = length;
+
+  /*   { */
+  /* #  warning debug code is enabled */
+  /*     FILE *fp = fopen ("tmp-minip12-plain-data.der", "wb"); */
+  /*     if (!fp || fwrite (p, n, 1, fp) != 1) */
+  /*       exit (2); */
+  /*     fclose (fp); */
+  /*   } */
+
+  if (parse_tag (&p, &n, &ti))
+    return 0;
+  if (ti.class || ti.tag != TAG_SEQUENCE)
+    return 0;
+  if (parse_tag (&p, &n, &ti))
+    return 0;
+
+  return 1;
+}
+
+
+static int
+parse_bag_encrypted_data (struct p12_parse_ctx_s *ctx,
+                          const unsigned char *buffer, size_t length,
+                          int startoffset, size_t *r_consumed)
+{
+  struct tag_info ti;
+  const unsigned char *p = buffer;
+  const unsigned char *p_start = buffer;
+  size_t n = length;
+  const char *where;
+  char salt[20];
+  size_t saltlen;
+  char iv[16];
+  unsigned int iter;
+  unsigned char *plain = NULL;
+  unsigned char *cram_buffer = NULL;
+  size_t consumed = 0; /* Number of bytes consumed from the original buffer. */
+  int is_3des = 0;
+  int is_pbes2 = 0;
+  int keyelem_count;
+
+  where = "start";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class != CLASS_CONTEXT || ti.tag)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.tag != TAG_SEQUENCE)
+    goto bailout;
+
+  where = "bag.encryptedData.version";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.tag != TAG_INTEGER || ti.length != 1 || *p != 0)
+    goto bailout;
+  p++; n--;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.tag != TAG_SEQUENCE)
+    goto bailout;
+
+  where = "bag.encryptedData.data";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.tag != TAG_OBJECT_ID || ti.length != DIM(oid_data)
+      || memcmp (p, oid_data, DIM(oid_data)))
+    goto bailout;
+  p += DIM(oid_data);
+  n -= DIM(oid_data);
+
+  where = "bag.encryptedData.keyinfo";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_SEQUENCE)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (!ti.class && ti.tag == TAG_OBJECT_ID
+      && ti.length == DIM(oid_pbeWithSHAAnd40BitRC2_CBC)
+      && !memcmp (p, oid_pbeWithSHAAnd40BitRC2_CBC,
+                  DIM(oid_pbeWithSHAAnd40BitRC2_CBC)))
+    {
+      p += DIM(oid_pbeWithSHAAnd40BitRC2_CBC);
+      n -= DIM(oid_pbeWithSHAAnd40BitRC2_CBC);
+    }
+  else if (!ti.class && ti.tag == TAG_OBJECT_ID
+      && ti.length == DIM(oid_pbeWithSHAAnd3_KeyTripleDES_CBC)
+      && !memcmp (p, oid_pbeWithSHAAnd3_KeyTripleDES_CBC,
+                  DIM(oid_pbeWithSHAAnd3_KeyTripleDES_CBC)))
+    {
+      p += DIM(oid_pbeWithSHAAnd3_KeyTripleDES_CBC);
+      n -= DIM(oid_pbeWithSHAAnd3_KeyTripleDES_CBC);
+      is_3des = 1;
+    }
+  else if (!ti.class && ti.tag == TAG_OBJECT_ID
+           && ti.length == DIM(oid_pkcs5PBES2)
+           && !memcmp (p, oid_pkcs5PBES2, ti.length))
+    {
+      p += ti.length;
+      n -= ti.length;
+      is_pbes2 = 1;
+    }
+  else
+    goto bailout;
+
+  if (is_pbes2)
+    {
+      where = "pkcs5PBES2-params";
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (!(!ti.class && ti.tag == TAG_OBJECT_ID
+            && ti.length == DIM(oid_pkcs5PBKDF2)
+            && !memcmp (p, oid_pkcs5PBKDF2, ti.length)))
+        goto bailout; /* Not PBKDF2.  */
+      p += ti.length;
+      n -= ti.length;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (!(!ti.class && ti.tag == TAG_OCTET_STRING
+            && ti.length >= 8 && ti.length < sizeof salt))
+        goto bailout;  /* No salt or unsupported length.  */
+      saltlen = ti.length;
+      memcpy (salt, p, saltlen);
+      p += saltlen;
+      n -= saltlen;
+
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (!(!ti.class && ti.tag == TAG_INTEGER && ti.length))
+        goto bailout;  /* No valid iteration count.  */
+      for (iter=0; ti.length; ti.length--)
+        {
+          iter <<= 8;
+          iter |= (*p++) & 0xff;
+          n--;
+        }
+      /* Note: We don't support the optional parameters but assume
+         that the algorithmIdentifier follows. */
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (!(!ti.class && ti.tag == TAG_OBJECT_ID
+            && ti.length == DIM(oid_aes128_CBC)
+            && !memcmp (p, oid_aes128_CBC, ti.length)))
+        goto bailout; /* Not AES-128.  */
+      p += ti.length;
+      n -= ti.length;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (!(!ti.class && ti.tag == TAG_OCTET_STRING && ti.length == sizeof iv))
+        goto bailout; /* Bad IV.  */
+      memcpy (iv, p, sizeof iv);
+      p += sizeof iv;
+      n -= sizeof iv;
+    }
+  else
+    {
+      where = "rc2or3des-params";
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_OCTET_STRING
+          || ti.length < 8 || ti.length > 20 )
+        goto bailout;
+      saltlen = ti.length;
+      memcpy (salt, p, saltlen);
+      p += saltlen;
+      n -= saltlen;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_INTEGER || !ti.length )
+        goto bailout;
+      for (iter=0; ti.length; ti.length--)
+        {
+          iter <<= 8;
+          iter |= (*p++) & 0xff;
+          n--;
+        }
+    }
+
+  where = "rc2or3desoraes-ciphertext";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+
+  consumed = p - p_start;
+  if (ti.class == CLASS_CONTEXT && ti.tag == 0 && ti.is_constructed && ti.ndef)
+    {
+      /* Mozilla exported certs now come with single byte chunks of
+         octet strings.  (Mozilla Firefox 1.0.4).  Arghh. */
+      where = "cram-rc2or3des-ciphertext";
+      cram_buffer = cram_octet_string ( p, &n, &consumed);
+      if (!cram_buffer)
+        goto bailout;
+      p = p_start = cram_buffer;
+      if (r_consumed)
+        *r_consumed = consumed;
+      r_consumed = NULL; /* Donot update that value on return. */
+      ti.length = n;
+    }
+  else if (ti.class == CLASS_CONTEXT && ti.tag == 0 && ti.is_constructed)
+    {
+      where = "octets-rc2or3des-ciphertext";
+      n = ti.length;
+      cram_buffer = cram_octet_string ( p, &n, &consumed);
+      if (!cram_buffer)
+        goto bailout;
+      p = p_start = cram_buffer;
+      if (r_consumed)
+        *r_consumed = consumed;
+      r_consumed = NULL; /* Do not update that value on return. */
+      ti.length = n;
+    }
+  else if (ti.class == CLASS_CONTEXT && ti.tag == 0 && ti.length )
+    ;
+  else
+    goto bailout;
+
+  if (opt_verbose)
+    log_info ("%lu bytes of %s encrypted text\n",ti.length,
+              is_pbes2?"AES128":is_3des?"3DES":"RC2");
+
+  plain = gcry_malloc_secure (ti.length);
+  if (!plain)
+    {
+      log_error ("error allocating decryption buffer\n");
+      goto bailout;
+    }
+  decrypt_block (p, plain, ti.length, salt, saltlen, iter,
+                 iv, is_pbes2?16:0, ctx->password,
+                 is_pbes2 ? GCRY_CIPHER_AES128 :
+                 is_3des  ? GCRY_CIPHER_3DES : GCRY_CIPHER_RFC2268_40,
+                 bag_decrypted_data_p);
+  n = ti.length;
+  startoffset = 0;
+  p_start = p = plain;
+
+  where = "outer.outer.seq";
+  if (parse_tag (&p, &n, &ti))
+    {
+      ctx->badpass = 1;
+      goto bailout;
+    }
+  if (ti.class || ti.tag != TAG_SEQUENCE)
+    {
+      ctx->badpass = 1;
+      goto bailout;
+    }
+
+  if (parse_tag (&p, &n, &ti))
+    {
+      ctx->badpass = 1;
+      goto bailout;
+    }
+
+  /* Loop over all certificates inside the bag. */
+  while (n)
+    {
+      int iscrlbag = 0;
+      int iskeybag = 0;
+
+      where = "certbag.nextcert";
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+
+      where = "certbag.objectidentifier";
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_OBJECT_ID)
+        goto bailout;
+      if ( ti.length == DIM(oid_pkcs_12_CertBag)
+           && !memcmp (p, oid_pkcs_12_CertBag, DIM(oid_pkcs_12_CertBag)))
+        {
+          p += DIM(oid_pkcs_12_CertBag);
+          n -= DIM(oid_pkcs_12_CertBag);
+        }
+      else if ( ti.length == DIM(oid_pkcs_12_CrlBag)
+           && !memcmp (p, oid_pkcs_12_CrlBag, DIM(oid_pkcs_12_CrlBag)))
+        {
+          p += DIM(oid_pkcs_12_CrlBag);
+          n -= DIM(oid_pkcs_12_CrlBag);
+          iscrlbag = 1;
+        }
+      else if ( ti.length == DIM(oid_pkcs_12_keyBag)
+           && !memcmp (p, oid_pkcs_12_keyBag, DIM(oid_pkcs_12_keyBag)))
+        {
+          /* The TrustedMIME plugin for MS Outlook started to create
+             files with just one outer 3DES encrypted container and
+             inside the certificates as well as the key. */
+          p += DIM(oid_pkcs_12_keyBag);
+          n -= DIM(oid_pkcs_12_keyBag);
+          iskeybag = 1;
+        }
+      else
+        goto bailout;
+
+      where = "certbag.before.certheader";
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class != CLASS_CONTEXT || ti.tag)
+        goto bailout;
+      if (iscrlbag)
+        {
+          log_info ("skipping unsupported crlBag\n");
+          p += ti.length;
+          n -= ti.length;
+        }
+      else if (iskeybag && ctx->privatekey)
+        {
+          log_info ("one keyBag already processed; skipping this one\n");
+          p += ti.length;
+          n -= ti.length;
+        }
+      else if (iskeybag)
+        {
+          int len;
+
+          if (opt_verbose)
+            log_info ("processing simple keyBag\n");
+
+          /* Fixme: This code is duplicated from parse_bag_data.  */
+          if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_SEQUENCE)
+            goto bailout;
+          if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_INTEGER
+              || ti.length != 1 || *p)
+            goto bailout;
+          p++; n--;
+          if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_SEQUENCE)
+            goto bailout;
+          len = ti.length;
+          if (parse_tag (&p, &n, &ti))
+            goto bailout;
+          if (len < ti.nhdr)
+            goto bailout;
+          len -= ti.nhdr;
+          if (ti.class || ti.tag != TAG_OBJECT_ID
+              || ti.length != DIM(oid_rsaEncryption)
+              || memcmp (p, oid_rsaEncryption,
+                         DIM(oid_rsaEncryption)))
+            goto bailout;
+          p += DIM (oid_rsaEncryption);
+          n -= DIM (oid_rsaEncryption);
+          if (len < ti.length)
+            goto bailout;
+          len -= ti.length;
+          if (n < len)
+            goto bailout;
+          p += len;
+          n -= len;
+          if ( parse_tag (&p, &n, &ti)
+               || ti.class || ti.tag != TAG_OCTET_STRING)
+            goto bailout;
+          if ( parse_tag (&p, &n, &ti)
+               || ti.class || ti.tag != TAG_SEQUENCE)
+            goto bailout;
+          len = ti.length;
+
+          log_assert (!ctx->privatekey);
+          ctx->privatekey = gcry_calloc (10, sizeof *ctx->privatekey);
+          if (!ctx->privatekey)
+            {
+              log_error ("error allocating private key element array\n");
+              goto bailout;
+            }
+          keyelem_count = 0;
+
+          where = "reading.keybag.key-parameters";
+          for (keyelem_count = 0; len && keyelem_count < 9;)
+            {
+              if ( parse_tag (&p, &n, &ti)
+                   || ti.class || ti.tag != TAG_INTEGER)
+                goto bailout;
+              if (len < ti.nhdr)
+                goto bailout;
+              len -= ti.nhdr;
+              if (len < ti.length)
+                goto bailout;
+              len -= ti.length;
+              if (!keyelem_count && ti.length == 1 && !*p)
+                ; /* ignore the very first one if it is a 0 */
+              else
+                {
+                  int rc;
+
+                  rc = gcry_mpi_scan (ctx->privatekey+keyelem_count,
+                                      GCRYMPI_FMT_USG, p,
+                                      ti.length, NULL);
+                  if (rc)
+                    {
+                      log_error ("error parsing key parameter: %s\n",
+                                 gpg_strerror (rc));
+                      goto bailout;
+                    }
+                  keyelem_count++;
+                }
+              p += ti.length;
+              n -= ti.length;
+            }
+          if (len)
+            goto bailout;
+        }
+      else
+        {
+          if (opt_verbose)
+            log_info ("processing certBag\n");
+          if (parse_tag (&p, &n, &ti))
+            goto bailout;
+          if (ti.class || ti.tag != TAG_SEQUENCE)
+            goto bailout;
+          if (parse_tag (&p, &n, &ti))
+            goto bailout;
+          if (ti.class || ti.tag != TAG_OBJECT_ID
+              || ti.length != DIM(oid_x509Certificate_for_pkcs_12)
+              || memcmp (p, oid_x509Certificate_for_pkcs_12,
+                         DIM(oid_x509Certificate_for_pkcs_12)))
+            goto bailout;
+          p += DIM(oid_x509Certificate_for_pkcs_12);
+          n -= DIM(oid_x509Certificate_for_pkcs_12);
+
+          where = "certbag.before.octetstring";
+          if (parse_tag (&p, &n, &ti))
+            goto bailout;
+          if (ti.class != CLASS_CONTEXT || ti.tag)
+            goto bailout;
+          if (parse_tag (&p, &n, &ti))
+            goto bailout;
+          if (ti.class || ti.tag != TAG_OCTET_STRING || ti.ndef)
+            goto bailout;
+
+          /* Return the certificate. */
+          if (ctx->certcb)
+            ctx->certcb (ctx->certcbarg, p, ti.length);
+
+          p += ti.length;
+          n -= ti.length;
+        }
+
+      /* Ugly hack to cope with the padding: Forget about the rest if
+         that is less or equal to the cipher's block length.  We can
+         reasonable assume that all valid data will be longer than
+         just one block. */
+      if (n <= (is_pbes2? 16:8))
+        n = 0;
+
+      /* Skip the optional SET with the pkcs12 cert attributes. */
+      if (n)
+        {
+          where = "bag.attributes";
+          if (parse_tag (&p, &n, &ti))
+            goto bailout;
+          if (!ti.class && ti.tag == TAG_SEQUENCE)
+            ; /* No attributes. */
+          else if (!ti.class && ti.tag == TAG_SET && !ti.ndef)
+            { /* The optional SET. */
+              p += ti.length;
+              n -= ti.length;
+              if (n <= (is_pbes2?16:8))
+                n = 0;
+              if (n && parse_tag (&p, &n, &ti))
+                goto bailout;
+            }
+          else
+            goto bailout;
+        }
+    }
+
+  if (r_consumed)
+    *r_consumed = consumed;
+  gcry_free (plain);
+  gcry_free (cram_buffer);
+  return 0;
+
+ bailout:
+  if (r_consumed)
+    *r_consumed = consumed;
+  gcry_free (plain);
+  gcry_free (cram_buffer);
+  log_error ("encryptedData error at \"%s\", offset %u\n",
+             where, (unsigned int)((p - p_start)+startoffset));
+  if (ctx->badpass)
+    {
+      /* Note, that the following string might be used by other programs
+         to check for a bad passphrase; it should therefore not be
+         translated or changed. */
+      log_error ("possibly bad passphrase given\n");
+    }
+  return -1;
+}
+
+
+/* Return true if the decryption of a bag_data object has likely
+   succeeded.  */
+static int
+bag_data_p (const void *plaintext, size_t length)
+{
+  struct tag_info ti;
+  const unsigned char *p = plaintext;
+  size_t n = length;
+
+/*   { */
+/* #  warning debug code is enabled */
+/*     FILE *fp = fopen ("tmp-minip12-plain-key.der", "wb"); */
+/*     if (!fp || fwrite (p, n, 1, fp) != 1) */
+/*       exit (2); */
+/*     fclose (fp); */
+/*   } */
+
+  if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_SEQUENCE)
+    return 0;
+  if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_INTEGER
+      || ti.length != 1 || *p)
+    return 0;
+
+  return 1;
+}
+
+
+static gpg_error_t
+parse_shrouded_key_bag (struct p12_parse_ctx_s *ctx,
+                        const unsigned char *buffer, size_t length,
+                        int startoffset,
+                        size_t *r_consumed)
+{
+  gpg_error_t err = 0;
+  struct tag_info ti;
+  const unsigned char *p = buffer;
+  const unsigned char *p_start = buffer;
+  size_t n = length;
+  const char *where;
+  char salt[20];
+  size_t saltlen;
+  char iv[16];
+  unsigned int iter;
+  int len;
+  unsigned char *plain = NULL;
+  unsigned char *cram_buffer = NULL;
+  size_t consumed = 0; /* Number of bytes consumed from the original buffer. */
+  int is_pbes2 = 0;
+  int keyelem_count = 0;
+
+  where = "shrouded_key_bag";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class != CLASS_CONTEXT || ti.tag)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_SEQUENCE)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_SEQUENCE)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class == 0 && ti.tag == TAG_OBJECT_ID
+      && ti.length == DIM(oid_pbeWithSHAAnd3_KeyTripleDES_CBC)
+      && !memcmp (p, oid_pbeWithSHAAnd3_KeyTripleDES_CBC,
+                  DIM(oid_pbeWithSHAAnd3_KeyTripleDES_CBC)))
+    {
+      p += DIM(oid_pbeWithSHAAnd3_KeyTripleDES_CBC);
+      n -= DIM(oid_pbeWithSHAAnd3_KeyTripleDES_CBC);
+    }
+  else if (ti.class == 0 && ti.tag == TAG_OBJECT_ID
+           && ti.length == DIM(oid_pkcs5PBES2)
+           && !memcmp (p, oid_pkcs5PBES2, DIM(oid_pkcs5PBES2)))
+    {
+      p += DIM(oid_pkcs5PBES2);
+      n -= DIM(oid_pkcs5PBES2);
+      is_pbes2 = 1;
+    }
+  else
+    goto bailout;
+
+  if (is_pbes2)
+    {
+      where = "shrouded_key_bag.pkcs5PBES2-params";
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (!(!ti.class && ti.tag == TAG_OBJECT_ID
+            && ti.length == DIM(oid_pkcs5PBKDF2)
+            && !memcmp (p, oid_pkcs5PBKDF2, ti.length)))
+        goto bailout; /* Not PBKDF2.  */
+      p += ti.length;
+      n -= ti.length;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (!(!ti.class && ti.tag == TAG_OCTET_STRING
+            && ti.length >= 8 && ti.length < sizeof salt))
+        goto bailout;  /* No salt or unsupported length.  */
+      saltlen = ti.length;
+      memcpy (salt, p, saltlen);
+      p += saltlen;
+      n -= saltlen;
+
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (!(!ti.class && ti.tag == TAG_INTEGER && ti.length))
+        goto bailout;  /* No valid iteration count.  */
+      for (iter=0; ti.length; ti.length--)
+        {
+          iter <<= 8;
+          iter |= (*p++) & 0xff;
+          n--;
+        }
+      /* Note: We don't support the optional parameters but assume
+         that the algorithmIdentifier follows. */
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (!(!ti.class && ti.tag == TAG_OBJECT_ID
+            && ti.length == DIM(oid_aes128_CBC)
+            && !memcmp (p, oid_aes128_CBC, ti.length)))
+        goto bailout; /* Not AES-128.  */
+      p += ti.length;
+      n -= ti.length;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (!(!ti.class && ti.tag == TAG_OCTET_STRING && ti.length == sizeof iv))
+        goto bailout; /* Bad IV.  */
+      memcpy (iv, p, sizeof iv);
+      p += sizeof iv;
+      n -= sizeof iv;
+    }
+  else
+    {
+      where = "shrouded_key_bag.3des-params";
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_OCTET_STRING
+          || ti.length < 8 || ti.length > 20)
+        goto bailout;
+      saltlen = ti.length;
+      memcpy (salt, p, saltlen);
+      p += saltlen;
+      n -= saltlen;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (ti.class || ti.tag != TAG_INTEGER || !ti.length )
+        goto bailout;
+      for (iter=0; ti.length; ti.length--)
+        {
+          iter <<= 8;
+          iter |= (*p++) & 0xff;
+          n--;
+        }
+    }
+
+  where = "shrouded_key_bag.3desoraes-ciphertext";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_OCTET_STRING || !ti.length )
+    goto bailout;
+
+  if (opt_verbose)
+    log_info ("%lu bytes of %s encrypted text\n",
+              ti.length, is_pbes2? "AES128":"3DES");
+
+  plain = gcry_malloc_secure (ti.length);
+  if (!plain)
+    {
+      log_error ("error allocating decryption buffer\n");
+      goto bailout;
+    }
+  consumed += p - p_start + ti.length;
+  decrypt_block (p, plain, ti.length, salt, saltlen, iter,
+                 iv, is_pbes2? 16:0, ctx->password,
+                 is_pbes2? GCRY_CIPHER_AES128 : GCRY_CIPHER_3DES,
+                 bag_data_p);
+  n = ti.length;
+  startoffset = 0;
+  p_start = p = plain;
+
+  where = "shrouded_key_bag.decrypted-text";
+  if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_SEQUENCE)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_INTEGER
+      || ti.length != 1 || *p)
+    goto bailout;
+  p++; n--;
+  if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_SEQUENCE)
+    goto bailout;
+  len = ti.length;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (len < ti.nhdr)
+    goto bailout;
+  len -= ti.nhdr;
+  if (ti.class || ti.tag != TAG_OBJECT_ID)
+    goto bailout;
+  /* gpgrt_log_printhex (p, ti.length, "OID:"); */
+  if (ti.length == DIM(oid_rsaEncryption)
+      && !memcmp (p, oid_rsaEncryption, DIM(oid_rsaEncryption)))
+    {
+      p += DIM (oid_rsaEncryption);
+      n -= DIM (oid_rsaEncryption);
+    }
+  else if (ti.length == DIM(oid_pcPublicKey)
+           && !memcmp (p, oid_pcPublicKey, DIM(oid_pcPublicKey)))
+    {
+      /* See RFC-5915 for the format.  */
+      p += DIM (oid_pcPublicKey);
+      n -= DIM (oid_pcPublicKey);
+      if (len < ti.length)
+        goto bailout;
+      len -= ti.length;
+      if (n < len)
+        goto bailout;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      /* gpgrt_log_debug ("ti=%d/%lu len=%lu\n",ti.class,ti.tag,ti.length); */
+      if (len < ti.nhdr)
+        goto bailout;
+      len -= ti.nhdr;
+      if (ti.class || ti.tag != TAG_OBJECT_ID)
+        goto bailout;
+      ksba_free (ctx->curve);
+      ctx->curve = ksba_oid_to_str (p, ti.length);
+      if (!ctx->curve)
+        goto bailout;
+      /* log_debug ("OID of curve is: %s\n", curve); */
+      p += ti.length;
+      n -= ti.length;
+    }
+  else
+    goto bailout;
+  if (len < ti.length)
+    goto bailout;
+  len -= ti.length;
+  if (n < len)
+    goto bailout;
+  p += len;
+  n -= len;
+  if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_OCTET_STRING)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_SEQUENCE)
+    goto bailout;
+  len = ti.length;
+
+  if (ctx->privatekey)
+    {
+      log_error ("a key has already been received\n");
+      goto bailout;
+    }
+  ctx->privatekey = gcry_calloc (10, sizeof *ctx->privatekey);
+  if (!ctx->privatekey)
+    {
+
+      log_error ("error allocating privatekey element array\n");
+      goto bailout;
+    }
+  keyelem_count = 0;
+
+  where = "shrouded_key_bag.reading.key-parameters";
+  if (ctx->curve)  /* ECC case.  */
+    {
+      if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_INTEGER)
+        goto bailout;
+      if (len < ti.nhdr)
+        goto bailout;
+      len -= ti.nhdr;
+      if (len < ti.length)
+        goto bailout;
+      len -= ti.length;
+      if (ti.length != 1 && *p != 1)
+        {
+          log_error ("error parsing private ecPublicKey parameter: %s\n",
+                     "bad version");
+          goto bailout;
+        }
+      p += ti.length;
+      n -= ti.length;
+      if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_OCTET_STRING)
+        goto bailout;
+      if (len < ti.nhdr)
+        goto bailout;
+      len -= ti.nhdr;
+      if (len < ti.length)
+        goto bailout;
+      len -= ti.length;
+      /* log_printhex (p, ti.length, "ecc q="); */
+      err = gcry_mpi_scan (ctx->privatekey, GCRYMPI_FMT_USG,
+                           p, ti.length, NULL);
+      if (err)
+        {
+          log_error ("error parsing key parameter: %s\n", gpg_strerror (err));
+          goto bailout;
+        }
+      p += ti.length;
+      n -= ti.length;
+
+      len = 0;  /* Skip the rest.  */
+    }
+  else  /* RSA case */
+    {
+      for (keyelem_count=0; len && keyelem_count < 9;)
+        {
+          if (parse_tag (&p, &n, &ti) || ti.class || ti.tag != TAG_INTEGER)
+            goto bailout;
+          if (len < ti.nhdr)
+            goto bailout;
+          len -= ti.nhdr;
+          if (len < ti.length)
+            goto bailout;
+          len -= ti.length;
+          if (!keyelem_count && ti.length == 1 && !*p)
+            ; /* ignore the very first one if it is a 0 */
+          else
+            {
+              err = gcry_mpi_scan (ctx->privatekey+keyelem_count,
+                                  GCRYMPI_FMT_USG, p, ti.length, NULL);
+              if (err)
+                {
+                  log_error ("error parsing key parameter: %s\n",
+                             gpg_strerror (err));
+                  goto bailout;
+                }
+              keyelem_count++;
+            }
+          p += ti.length;
+          n -= ti.length;
+        }
+    }
+  if (len)
+    goto bailout;
+
+  goto leave;
+
+ bailout:
+  gcry_free (plain);
+  log_error ("data error at \"%s\", offset %zu\n",
+              where, (size_t)((p - p_start) + startoffset));
+  if (!err)
+    err = gpg_error (GPG_ERR_GENERAL);
+
+ leave:
+  gcry_free (cram_buffer);
+  if (r_consumed)
+    *r_consumed = consumed;
+  return err;
+}
+
+
+static gpg_error_t
+parse_cert_bag (struct p12_parse_ctx_s *ctx,
+                const unsigned char *buffer, size_t length,
+                int startoffset,
+                size_t *r_consumed)
+{
+  gpg_error_t err = 0;
+  struct tag_info ti;
+  const unsigned char *p = buffer;
+  const unsigned char *p_start = buffer;
+  size_t n = length;
+  const char *where;
+  size_t consumed = 0; /* Number of bytes consumed from the original buffer. */
+
+  if (opt_verbose)
+    log_info ("processing certBag\n");
+
+  /* Expect:
+   *  [0]
+   *    SEQUENCE
+   *      OBJECT IDENTIFIER pkcs-12-certBag
+   */
+  where = "certbag.before.certheader";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class != CLASS_CONTEXT || ti.tag)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_SEQUENCE)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_OBJECT_ID
+      || ti.length != DIM(oid_x509Certificate_for_pkcs_12)
+      || memcmp (p, oid_x509Certificate_for_pkcs_12,
+                 DIM(oid_x509Certificate_for_pkcs_12)))
+    goto bailout;
+  p += DIM(oid_x509Certificate_for_pkcs_12);
+  n -= DIM(oid_x509Certificate_for_pkcs_12);
+
+  /* Expect:
+   *  [0]
+   *    OCTET STRING encapsulates -- the certificates
+   */
+  where = "certbag.before.octetstring";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class != CLASS_CONTEXT || ti.tag)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_OCTET_STRING || ti.ndef)
+    goto bailout;
+
+  /* Return the certificate from the octet string. */
+  if (ctx->certcb)
+     ctx->certcb (ctx->certcbarg, p, ti.length);
+
+  p += ti.length;
+  n -= ti.length;
+
+  if (!n)
+    goto leave;  /* ready.  */
+
+  /* Expect:
+   *  SET
+   *    SEQUENCE  -- we actually ignore this.
+   */
+  where = "certbag.attribute_set";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (!ti.class && ti.tag == TAG_SET && !ti.ndef)
+    { /* Comsume the optional SET. */
+      p += ti.length;
+      n -= ti.length;
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+    }
+
+  goto leave;
+
+ bailout:
+  log_error ( "data error at \"%s\", offset %u\n",
+              where, (unsigned int)((p - p_start) + startoffset));
+  err = gpg_error (GPG_ERR_GENERAL);
+
+ leave:
+  if (r_consumed)
+    *r_consumed = consumed;
+  return err;
+}
+
+
+static gpg_error_t
+parse_bag_data (struct p12_parse_ctx_s *ctx,
+                const unsigned char *buffer, size_t length, int startoffset,
+                size_t *r_consumed)
+{
+  gpg_error_t err = 0;
+  struct tag_info ti;
+  const unsigned char *p = buffer;
+  const unsigned char *p_start = buffer;
+  size_t n = length;
+  const char *where;
+  unsigned char *cram_buffer = NULL;
+  size_t consumed = 0; /* Number of bytes consumed from the original buffer. */
+
+  /* Expect:
+   * [0]
+   *   OCTET STRING, encapsulates
+   */
+  where = "data";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class != CLASS_CONTEXT || ti.tag)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_OCTET_STRING)
+    goto bailout;
+
+
+  consumed = p - p_start;
+  if (ti.is_constructed && ti.ndef)
+    {
+      /* Mozilla exported certs now come with single byte chunks of
+         octet strings.  (Mozilla Firefox 1.0.4).  Arghh. */
+      where = "data.cram_os";
+      cram_buffer = cram_octet_string ( p, &n, &consumed);
+      if (!cram_buffer)
+        goto bailout;
+      p = p_start = cram_buffer;
+      if (r_consumed)
+        *r_consumed = consumed;
+      r_consumed = NULL; /* Ugly hack to not update that value on return. */
+    }
+
+  /* Expect:
+   * SEQUENCE
+   *   SEQUENCE
+   */
+  where = "data.2seqs";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_SEQUENCE)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_SEQUENCE)
+    goto bailout;
+
+  /* Expect:
+   * OBJECT IDENTIFIER
+   */
+  where = "data.oid";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class || ti.tag != TAG_OBJECT_ID)
+    goto bailout;
+
+  /* Now divert to the actual parser.  */
+  if (ti.length == DIM(oid_pkcs_12_pkcs_8ShroudedKeyBag)
+      && !memcmp (p, oid_pkcs_12_pkcs_8ShroudedKeyBag,
+                 DIM(oid_pkcs_12_pkcs_8ShroudedKeyBag)))
+    {
+      p += DIM(oid_pkcs_12_pkcs_8ShroudedKeyBag);
+      n -= DIM(oid_pkcs_12_pkcs_8ShroudedKeyBag);
+
+      if (parse_shrouded_key_bag (ctx, p, n,
+                                  startoffset + (p - p_start), r_consumed))
+        goto bailout;
+    }
+  else if ( ti.length == DIM(oid_pkcs_12_CertBag)
+            && !memcmp (p, oid_pkcs_12_CertBag, DIM(oid_pkcs_12_CertBag)))
+    {
+      p += DIM(oid_pkcs_12_CertBag);
+      n -= DIM(oid_pkcs_12_CertBag);
+
+      if (parse_cert_bag (ctx, p, n,
+                          startoffset + (p - p_start), r_consumed))
+        goto bailout;
+    }
+  else
+    goto bailout;
+
+  goto leave;
+
+ bailout:
+  log_error ( "data error at \"%s\", offset %u\n",
+              where, (unsigned int)((p - p_start) + startoffset));
+  err = gpg_error (GPG_ERR_GENERAL);
+
+ leave:
+  gcry_free (cram_buffer);
+  if (r_consumed) /* Store the number of consumed bytes unless already done. */
+    *r_consumed = consumed;
+  return err;
+}
+
+
+/* Parse a PKCS12 object and return an array of MPI representing the
+   secret key parameters.  This is a very limited implementation in
+   that it is only able to look for 3DES encoded encryptedData and
+   tries to extract the first private key object it finds.  In case of
+   an error NULL is returned. CERTCB and CERRTCBARG are used to pass
+   X.509 certificates back to the caller.  If R_CURVE is not NULL and
+   an ECC key was found the OID of the curve is stored there. */
+gcry_mpi_t *
+p12_parse (const unsigned char *buffer, size_t length, const char *pw,
+           void (*certcb)(void*, const unsigned char*, size_t),
+           void *certcbarg, int *r_badpass, char **r_curve)
+{
+  struct tag_info ti;
+  const unsigned char *p = buffer;
+  const unsigned char *p_start = buffer;
+  size_t n = length;
+  const char *where;
+  int bagseqlength, len;
+  int bagseqndef, lenndef;
+  unsigned char *cram_buffer = NULL;
+  size_t consumed;
+  struct p12_parse_ctx_s ctx = { NULL };
+
+  *r_badpass = 0;
+
+  ctx.certcb = certcb;
+  ctx.certcbarg = certcbarg;
+  ctx.password = pw;
+
+
+  where = "pfx";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.tag != TAG_SEQUENCE)
+    goto bailout;
+
+  where = "pfxVersion";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.tag != TAG_INTEGER || ti.length != 1 || *p != 3)
+    goto bailout;
+  p++; n--;
+
+  where = "authSave";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.tag != TAG_SEQUENCE)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.tag != TAG_OBJECT_ID || ti.length != DIM(oid_data)
+      || memcmp (p, oid_data, DIM(oid_data)))
+    goto bailout;
+  p += DIM(oid_data);
+  n -= DIM(oid_data);
+
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class != CLASS_CONTEXT || ti.tag)
+    goto bailout;
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class != CLASS_UNIVERSAL || ti.tag != TAG_OCTET_STRING)
+    goto bailout;
+
+  if (ti.is_constructed && ti.ndef)
+    {
+      /* Mozilla exported certs now come with single byte chunks of
+         octet strings.  (Mozilla Firefox 1.0.4).  Arghh. */
+      where = "cram-bags";
+      cram_buffer = cram_octet_string ( p, &n, NULL);
+      if (!cram_buffer)
+        goto bailout;
+      p = p_start = cram_buffer;
+    }
+
+  where = "bags";
+  if (parse_tag (&p, &n, &ti))
+    goto bailout;
+  if (ti.class != CLASS_UNIVERSAL || ti.tag != TAG_SEQUENCE)
+    goto bailout;
+  bagseqndef = ti.ndef;
+  bagseqlength = ti.length;
+  while (bagseqlength || bagseqndef)
+    {
+      /* log_debug ("p12_parse: at offset %ld\n", (p - p_start)); */
+      where = "bag-sequence";
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (bagseqndef && ti.class == CLASS_UNIVERSAL
+          && !ti.tag && !ti.is_constructed)
+        break; /* Ready */
+      if (ti.class != CLASS_UNIVERSAL || ti.tag != TAG_SEQUENCE)
+        goto bailout;
+
+      if (!bagseqndef)
+        {
+          if (bagseqlength < ti.nhdr)
+            goto bailout;
+          bagseqlength -= ti.nhdr;
+          if (bagseqlength < ti.length)
+            goto bailout;
+          bagseqlength -= ti.length;
+        }
+      lenndef = ti.ndef;
+      len = ti.length;
+
+      if (parse_tag (&p, &n, &ti))
+        goto bailout;
+      if (lenndef)
+        len = ti.nhdr;
+      else
+        len -= ti.nhdr;
+
+      if (ti.tag == TAG_OBJECT_ID && ti.length == DIM(oid_encryptedData)
+          && !memcmp (p, oid_encryptedData, DIM(oid_encryptedData)))
+        {
+
+          p += DIM(oid_encryptedData);
+          n -= DIM(oid_encryptedData);
+          if (!lenndef)
+            len -= DIM(oid_encryptedData);
+          where = "bag.encryptedData";
+          consumed = 0;
+          if (parse_bag_encrypted_data (&ctx, p, n, (p - p_start), &consumed))
+            {
+              *r_badpass = ctx.badpass;
+              goto bailout;
+            }
+          if (lenndef)
+            len += consumed;
+        }
+      else if (ti.tag == TAG_OBJECT_ID && ti.length == DIM(oid_data)
+               && !memcmp (p, oid_data, DIM(oid_data)))
+        {
+          p += DIM(oid_data);
+          n -= DIM(oid_data);
+          if (!lenndef)
+            len -= DIM(oid_data);
+
+          where = "bag.data";
+          consumed = 0;
+          if (parse_bag_data (&ctx, p, n, (p - p_start), &consumed))
+            goto bailout;
+          if (lenndef)
+            len += consumed;
+        }
+      else
+        {
+          log_info ("unknown outer bag type - skipped\n");
+          p += ti.length;
+          n -= ti.length;
+        }
+
+      if (len < 0 || len > n)
+        goto bailout;
+      p += len;
+      n -= len;
+      if (lenndef)
+        {
+          /* Need to skip the Null Tag. */
+          if (parse_tag (&p, &n, &ti))
+            goto bailout;
+          if (!(ti.class == CLASS_UNIVERSAL && !ti.tag && !ti.is_constructed))
+            goto bailout;
+        }
+    }
+
+  gcry_free (cram_buffer);
+  if (r_curve)
+    *r_curve = ctx.curve;
+  else
+    gcry_free (ctx.curve);
+
+  return ctx.privatekey;
+
+ bailout:
+  log_error ("error at \"%s\", offset %u\n",
+             where, (unsigned int)(p - p_start));
+  if (ctx.privatekey)
+    {
+      int i;
+
+      for (i=0; ctx.privatekey[i]; i++)
+        gcry_mpi_release (ctx.privatekey[i]);
+      gcry_free (ctx.privatekey);
+      ctx.privatekey = NULL;
+    }
+  gcry_free (cram_buffer);
+  gcry_free (ctx.curve);
+  if (r_curve)
+    *r_curve = NULL;
+  return NULL;
+}
+
+
+
+static size_t
+compute_tag_length (size_t n)
+{
+  int needed = 0;
+
+  if (n < 128)
+    needed += 2; /* tag and one length byte */
+  else if (n < 256)
+    needed += 3; /* tag, number of length bytes, 1 length byte */
+  else if (n < 65536)
+    needed += 4; /* tag, number of length bytes, 2 length bytes */
+  else
+    {
+      log_error ("object too larger to encode\n");
+      return 0;
+    }
+  return needed;
+}
+
+static unsigned char *
+store_tag_length (unsigned char *p, int tag, size_t n)
+{
+  if (tag == TAG_SEQUENCE)
+    tag |= 0x20; /* constructed */
+
+  *p++ = tag;
+  if (n < 128)
+    *p++ = n;
+  else if (n < 256)
+    {
+      *p++ = 0x81;
+      *p++ = n;
+    }
+  else if (n < 65536)
+    {
+      *p++ = 0x82;
+      *p++ = n >> 8;
+      *p++ = n;
+    }
+
+  return p;
+}
+
+
+/* Create the final PKCS-12 object from the sequences contained in
+   SEQLIST.  PW is the password. That array is terminated with an NULL
+   object. */
+static unsigned char *
+create_final (struct buffer_s *sequences, const char *pw, size_t *r_length)
+{
+  int i;
+  size_t needed = 0;
+  size_t len[8], n;
+  unsigned char *macstart;
+  size_t maclen;
+  unsigned char *result, *p;
+  size_t resultlen;
+  char salt[8];
+  unsigned char keybuf[20];
+  gcry_md_hd_t md;
+  int rc;
+  int with_mac = 1;
+
+
+  /* 9 steps to create the pkcs#12 Krampf. */
+
+  /* 8. The MAC. */
+  /* We add this at step 0. */
+
+  /* 7. All the buffers. */
+  for (i=0; sequences[i].buffer; i++)
+    needed += sequences[i].length;
+
+  /* 6. This goes into a sequences. */
+  len[6] = needed;
+  n = compute_tag_length (needed);
+  needed += n;
+
+  /* 5. Encapsulate all in an octet string. */
+  len[5] = needed;
+  n = compute_tag_length (needed);
+  needed += n;
+
+  /* 4. And tag it with [0]. */
+  len[4] = needed;
+  n = compute_tag_length (needed);
+  needed += n;
+
+  /* 3. Prepend an data OID. */
+  needed += 2 + DIM (oid_data);
+
+  /* 2. Put all into a sequences. */
+  len[2] = needed;
+  n = compute_tag_length (needed);
+  needed += n;
+
+  /* 1. Prepend the version integer 3. */
+  needed += 3;
+
+  /* 0. And the final outer sequence. */
+  if (with_mac)
+    needed += DIM (data_mactemplate);
+  len[0] = needed;
+  n = compute_tag_length (needed);
+  needed += n;
+
+  /* Allocate a buffer. */
+  result = gcry_malloc (needed);
+  if (!result)
+    {
+      log_error ("error allocating buffer\n");
+      return NULL;
+    }
+  p = result;
+
+  /* 0. Store the very outer sequence. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[0]);
+
+  /* 1. Store the version integer 3. */
+  *p++ = TAG_INTEGER;
+  *p++ = 1;
+  *p++ = 3;
+
+  /* 2. Store another sequence. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[2]);
+
+  /* 3. Store the data OID. */
+  p = store_tag_length (p, TAG_OBJECT_ID, DIM (oid_data));
+  memcpy (p, oid_data, DIM (oid_data));
+  p += DIM (oid_data);
+
+  /* 4. Next comes a context tag. */
+  p = store_tag_length (p, 0xa0, len[4]);
+
+  /* 5. And an octet string. */
+  p = store_tag_length (p, TAG_OCTET_STRING, len[5]);
+
+  /* 6. And the inner sequence. */
+  macstart = p;
+  p = store_tag_length (p, TAG_SEQUENCE, len[6]);
+
+  /* 7. Append all the buffers. */
+  for (i=0; sequences[i].buffer; i++)
+    {
+      memcpy (p, sequences[i].buffer, sequences[i].length);
+      p += sequences[i].length;
+    }
+
+  if (with_mac)
+    {
+      /* Intermezzo to compute the MAC. */
+      maclen = p - macstart;
+      gcry_randomize (salt, 8, GCRY_STRONG_RANDOM);
+      if (string_to_key (3, salt, 8, 2048, pw, 20, keybuf))
+        {
+          gcry_free (result);
+          return NULL;
+        }
+      rc = gcry_md_open (&md, GCRY_MD_SHA1, GCRY_MD_FLAG_HMAC);
+      if (rc)
+        {
+          log_error ("gcry_md_open failed: %s\n", gpg_strerror (rc));
+          gcry_free (result);
+          return NULL;
+        }
+      rc = gcry_md_setkey (md, keybuf, 20);
+      if (rc)
+        {
+          log_error ("gcry_md_setkey failed: %s\n", gpg_strerror (rc));
+          gcry_md_close (md);
+          gcry_free (result);
+          return NULL;
+        }
+      gcry_md_write (md, macstart, maclen);
+
+      /* 8. Append the MAC template and fix it up. */
+      memcpy (p, data_mactemplate, DIM (data_mactemplate));
+      memcpy (p + DATA_MACTEMPLATE_SALT_OFF, salt, 8);
+      memcpy (p + DATA_MACTEMPLATE_MAC_OFF, gcry_md_read (md, 0), 20);
+      p += DIM (data_mactemplate);
+      gcry_md_close (md);
+    }
+
+  /* Ready. */
+  resultlen = p - result;
+  if (needed != resultlen)
+    log_debug ("p12_parse: warning: length mismatch: %lu, %lu\n",
+               (unsigned long)needed, (unsigned long)resultlen);
+
+  *r_length = resultlen;
+  return result;
+}
+
+
+/* Build a DER encoded SEQUENCE with the key:
+ *
+ * SEQUENCE {  -- OneAsymmetricKey (RFC-5958)
+ *   INTEGER 0
+ *   SEQUENCE {
+ *     OBJECT IDENTIFIER rsaEncryption (1 2 840 113549 1 1 1)
+ *     NULL
+ *     }
+ *   OCTET STRING, encapsulates {
+ *     SEQUENCE {   -- RSAPrivateKey (RFC-3447)
+ *       INTEGER 0  -- Version
+ *       INTEGER    -- n
+ *       INTEGER    -- e
+ *       INTEGER    -- d
+ *       INTEGER    -- p
+ *       INTEGER    -- q
+ *       INTEGER    -- d mod (p-1)
+ *       INTEGER    -- d mod (q-1)
+ *       INTEGER    -- q^-1 mod p
+ *       }
+ *     }
+ *   }
+ *
+ * MODE controls what is being generated:
+ *   0 - As described above
+ *   1 - Ditto but without the padding
+ *   2 - Only the inner part (pkcs#1)
+ */
+
+static unsigned char *
+build_rsa_key_sequence (gcry_mpi_t *kparms, int mode, size_t *r_length)
+{
+  int rc, i;
+  size_t needed, n;
+  unsigned char *plain, *p;
+  size_t plainlen;
+  size_t outseqlen, oidseqlen, octstrlen, inseqlen;
+
+  needed = 3; /* The version integer with value 0. */
+  for (i=0; kparms[i]; i++)
+    {
+      n = 0;
+      rc = gcry_mpi_print (GCRYMPI_FMT_STD, NULL, 0, &n, kparms[i]);
+      if (rc)
+        {
+          log_error ("error formatting parameter: %s\n", gpg_strerror (rc));
+          return NULL;
+        }
+      needed += n;
+      n = compute_tag_length (n);
+      if (!n)
+        return NULL;
+      needed += n;
+    }
+  if (i != 8)
+    {
+      log_error ("invalid parameters for p12_build\n");
+      return NULL;
+    }
+  /* Now this all goes into a sequence. */
+  inseqlen = needed;
+  n = compute_tag_length (needed);
+  if (!n)
+    return NULL;
+  needed += n;
+
+  if (mode != 2)
+    {
+      /* Encapsulate all into an octet string. */
+      octstrlen = needed;
+      n = compute_tag_length (needed);
+      if (!n)
+        return NULL;
+      needed += n;
+      /* Prepend the object identifier sequence. */
+      oidseqlen = 2 + DIM (oid_rsaEncryption) + 2;
+      needed += 2 + oidseqlen;
+      /* The version number. */
+      needed += 3;
+      /* And finally put the whole thing into a sequence. */
+      outseqlen = needed;
+      n = compute_tag_length (needed);
+      if (!n)
+        return NULL;
+      needed += n;
+    }
+
+  /* allocate 8 extra bytes for padding */
+  plain = gcry_malloc_secure (needed+8);
+  if (!plain)
+    {
+      log_error ("error allocating encryption buffer\n");
+      return NULL;
+    }
+
+  /* And now fill the plaintext buffer. */
+  p = plain;
+  if (mode != 2)
+    {
+      p = store_tag_length (p, TAG_SEQUENCE, outseqlen);
+      /* Store version. */
+      *p++ = TAG_INTEGER;
+      *p++ = 1;
+      *p++ = 0;
+      /* Store object identifier sequence. */
+      p = store_tag_length (p, TAG_SEQUENCE, oidseqlen);
+      p = store_tag_length (p, TAG_OBJECT_ID, DIM (oid_rsaEncryption));
+      memcpy (p, oid_rsaEncryption, DIM (oid_rsaEncryption));
+      p += DIM (oid_rsaEncryption);
+      *p++ = TAG_NULL;
+      *p++ = 0;
+      /* Start with the octet string. */
+      p = store_tag_length (p, TAG_OCTET_STRING, octstrlen);
+    }
+
+  p = store_tag_length (p, TAG_SEQUENCE, inseqlen);
+  /* Store the key parameters. */
+  *p++ = TAG_INTEGER;
+  *p++ = 1;
+  *p++ = 0;
+  for (i=0; kparms[i]; i++)
+    {
+      n = 0;
+      rc = gcry_mpi_print (GCRYMPI_FMT_STD, NULL, 0, &n, kparms[i]);
+      if (rc)
+        {
+          log_error ("oops: error formatting parameter: %s\n",
+                     gpg_strerror (rc));
+          gcry_free (plain);
+          return NULL;
+        }
+      p = store_tag_length (p, TAG_INTEGER, n);
+
+      n = plain + needed - p;
+      rc = gcry_mpi_print (GCRYMPI_FMT_STD, p, n, &n, kparms[i]);
+      if (rc)
+        {
+          log_error ("oops: error storing parameter: %s\n",
+                     gpg_strerror (rc));
+          gcry_free (plain);
+          return NULL;
+        }
+      p += n;
+    }
+
+  plainlen = p - plain;
+  log_assert (needed == plainlen);
+
+  if (!mode)
+    {
+      /* Append some pad characters; we already allocated extra space. */
+      n = 8 - plainlen % 8;
+      for (i=0; i < n; i++, plainlen++)
+        *p++ = n;
+    }
+
+  *r_length = plainlen;
+  return plain;
+}
+
+
+/* Build a DER encoded SEQUENCE for an ECC key:
+ *
+ * SEQUENCE {  -- OneAsymmetricKey (RFC-5958)
+ *   INTEGER 0
+ *   SEQUENCE {
+ *     OBJECT IDENTIFIER ecPublicKey (1 2 840 10045 2 1)
+ *     OBJECT IDENTIFIER -- curvename
+ *     }
+ *   OCTET STRING, encapsulates {
+ *     SEQUENCE {      -- ECPrivateKey
+ *       INTEGER  1    --  version
+ *       OCTET STRING  -- privateKey
+ *       [1] {
+ *          BIT STRING - publicKey
+ *       }
+ *     }
+ *   }
+ * }
+ *
+ * For details see RFC-5480 and RFC-5915 (ECparameters are not created).
+ *
+ * KPARMS[0] := Opaque MPI with the curve name as dotted-decimal string.
+ * KPARMS[1] := Opaque MPI with the public key (q)
+ * KPARMS[2] := Opaque MPI with the private key (d)
+ * MODE controls what is being generated:
+ *    0 - As described above
+ *    1 - Ditto but without the extra padding needed for pcsk#12
+ *    2 - Only the octet string (ECPrivateKey)
+ */
+
+static unsigned char *
+build_ecc_key_sequence (gcry_mpi_t *kparms, int mode, size_t *r_length)
+{
+  gpg_error_t err;
+  unsigned int nbits, n;
+  const unsigned char *s;
+  char *p;
+  tlv_builder_t tb;
+  void *result;
+  size_t resultlen;
+  const char *curve;
+  unsigned int curvebits;
+  int e;
+  int i;
+  int strip_one;
+
+  for (i=0; kparms[i]; i++)
+    ;
+  if (i != 3)
+    {
+      log_error ("%s: invalid number of parameters\n", __func__);
+      return NULL;
+    }
+
+  s = gcry_mpi_get_opaque (kparms[0], &nbits);
+  n = (nbits+7)/8;
+  p = xtrymalloc (n + 1);
+  if (!p)
+    {
+      err = gpg_error_from_syserror ();
+      log_error ("%s:%d: error getting parameter: %s\n",
+                 __func__, __LINE__, gpg_strerror (err));
+      return NULL;
+    }
+  memcpy (p, s, n);
+  p[n] = 0;
+  /* We need to use our OpenPGP mapping to turn a curve name into its
+   * canonical numerical OID.  We should have a Libgcrypt function to
+   * do this; see bug report #4926.  */
+  curve = openpgp_curve_to_oid (p, &curvebits, NULL);
+  xfree (p);
+  if (!curve)
+    {
+      err = gpg_error (GPG_ERR_UNKNOWN_CURVE);
+      log_error ("%s:%d: error getting parameter: %s\n",
+                 __func__, __LINE__, gpg_strerror (err));
+      return NULL;
+    }
+
+  /* Unfortunately the private key D may come with a single leading
+   * zero byte.  This is becuase at some point it was treated as
+   * signed MPI and the code made sure that it is always interpreted
+   * as unsigned.  Fortunately we got the size of the curve and can
+   * detect such a case reliable.  */
+  s = gcry_mpi_get_opaque (kparms[2], &nbits);
+  n = (nbits+7)/8;
+  strip_one = (n == (curvebits+7)/8 + 1 && !*s);
+
+
+  tb = tlv_builder_new (1);
+  if (!tb)
+    {
+      err = gpg_error_from_syserror ();
+      log_error ("%s:%d: error creating new TLV builder: %s\n",
+                 __func__, __LINE__, gpg_strerror (err));
+      return NULL;
+    }
+  e = 0;
+  tlv_builder_add_tag (tb, 0, TAG_SEQUENCE);
+  tlv_builder_add_ptr (tb, 0, TAG_INTEGER, "\0", 1);
+  tlv_builder_add_tag (tb, 0, TAG_SEQUENCE);
+  e|= builder_add_oid (tb, 0, "1.2.840.10045.2.1");
+  e|= builder_add_oid (tb, 0, curve);
+  tlv_builder_add_end (tb);
+  tlv_builder_add_tag (tb, 0, TAG_OCTET_STRING);
+  tlv_builder_add_tag (tb, 0, TAG_SEQUENCE);
+  tlv_builder_add_ptr (tb, 0, TAG_INTEGER, "\x01", 1);
+  e|= builder_add_mpi (tb, 0, TAG_OCTET_STRING, kparms[2], strip_one);
+  tlv_builder_add_tag (tb, CLASS_CONTEXT, 1);
+  e|= builder_add_mpi (tb, 0, TAG_BIT_STRING, kparms[1], 0);
+  tlv_builder_add_end (tb);
+  tlv_builder_add_end (tb);
+  tlv_builder_add_end (tb);
+  tlv_builder_add_end (tb);
+
+  err = tlv_builder_finalize (tb, &result, &resultlen);
+  if (err || e)
+    {
+      if (!err)
+        err = gpg_error (GPG_ERR_GENERAL);
+      log_error ("%s:%d: tlv building failed: %s\n",
+                 __func__, __LINE__, gpg_strerror (err));
+      return NULL;
+    }
+
+  /* Append some pad characters if needed. */
+  if (!mode && (n = 8 - resultlen % 8))
+    {
+      p = xtrymalloc_secure (resultlen + n);
+      if (!p)
+        {
+          err = gpg_error_from_syserror ();
+          log_error ("%s:%d: error allocating buffer: %s\n",
+                     __func__, __LINE__, gpg_strerror (err));
+          xfree (result);
+          return NULL;
+        }
+      memcpy (p, result, resultlen);
+      xfree (result);
+      result = p;
+      p = (unsigned char*)result + resultlen;
+      for (i=0; i < n; i++, resultlen++)
+        *p++ = n;
+    }
+
+  *r_length = resultlen;
+
+  return result;
+}
+
+
+static unsigned char *
+build_key_bag (unsigned char *buffer, size_t buflen, char *salt,
+               const unsigned char *sha1hash, const char *keyidstr,
+               size_t *r_length)
+{
+  size_t len[11], needed;
+  unsigned char *p, *keybag;
+  size_t keybaglen;
+
+  /* Walk 11 steps down to collect the info: */
+
+  /* 10. The data goes into an octet string. */
+  needed = compute_tag_length (buflen);
+  needed += buflen;
+
+  /* 9. Prepend the algorithm identifier. */
+  needed += DIM (data_3desiter2048);
+
+  /* 8. Put a sequence around. */
+  len[8] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 7. Prepend a [0] tag. */
+  len[7] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 6b. The attributes which are appended at the end. */
+  if (sha1hash)
+    needed += DIM (data_attrtemplate) + 20;
+
+  /* 6. Prepend the shroudedKeyBag OID. */
+  needed += 2 + DIM (oid_pkcs_12_pkcs_8ShroudedKeyBag);
+
+  /* 5+4. Put all into two sequences. */
+  len[5] = needed;
+  needed += compute_tag_length ( needed);
+  len[4] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 3. This all goes into an octet string. */
+  len[3] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 2. Prepend another [0] tag. */
+  len[2] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 1. Prepend the data OID. */
+  needed += 2 + DIM (oid_data);
+
+  /* 0. Prepend another sequence. */
+  len[0] = needed;
+  needed += compute_tag_length (needed);
+
+  /* Now that we have all length information, allocate a buffer. */
+  p = keybag = gcry_malloc (needed);
+  if (!keybag)
+    {
+      log_error ("error allocating buffer\n");
+      return NULL;
+    }
+
+  /* Walk 11 steps up to store the data. */
+
+  /* 0. Store the first sequence. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[0]);
+
+  /* 1. Store the data OID. */
+  p = store_tag_length (p, TAG_OBJECT_ID, DIM (oid_data));
+  memcpy (p, oid_data, DIM (oid_data));
+  p += DIM (oid_data);
+
+  /* 2. Store a [0] tag. */
+  p = store_tag_length (p, 0xa0, len[2]);
+
+  /* 3. And an octet string. */
+  p = store_tag_length (p, TAG_OCTET_STRING, len[3]);
+
+  /* 4+5. Two sequences. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[4]);
+  p = store_tag_length (p, TAG_SEQUENCE, len[5]);
+
+  /* 6. Store the shroudedKeyBag OID. */
+  p = store_tag_length (p, TAG_OBJECT_ID,
+                        DIM (oid_pkcs_12_pkcs_8ShroudedKeyBag));
+  memcpy (p, oid_pkcs_12_pkcs_8ShroudedKeyBag,
+          DIM (oid_pkcs_12_pkcs_8ShroudedKeyBag));
+  p += DIM (oid_pkcs_12_pkcs_8ShroudedKeyBag);
+
+  /* 7. Store a [0] tag. */
+  p = store_tag_length (p, 0xa0, len[7]);
+
+  /* 8. Store a sequence. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[8]);
+
+  /* 9. Now for the pre-encoded algorithm identifier and the salt. */
+  memcpy (p, data_3desiter2048, DIM (data_3desiter2048));
+  memcpy (p + DATA_3DESITER2048_SALT_OFF, salt, 8);
+  p += DIM (data_3desiter2048);
+
+  /* 10. And the octet string with the encrypted data. */
+  p = store_tag_length (p, TAG_OCTET_STRING, buflen);
+  memcpy (p, buffer, buflen);
+  p += buflen;
+
+  /* Append the attributes whose length we calculated at step 2b. */
+  if (sha1hash)
+    {
+      int i;
+
+      memcpy (p, data_attrtemplate, DIM (data_attrtemplate));
+      for (i=0; i < 8; i++)
+        p[DATA_ATTRTEMPLATE_KEYID_OFF+2*i+1] = keyidstr[i];
+      p += DIM (data_attrtemplate);
+      memcpy (p, sha1hash, 20);
+      p += 20;
+    }
+
+
+  keybaglen = p - keybag;
+  if (needed != keybaglen)
+    log_debug ("p12_parse: warning: length mismatch: %lu, %lu\n",
+               (unsigned long)needed, (unsigned long)keybaglen);
+
+  *r_length = keybaglen;
+  return keybag;
+}
+
+
+static unsigned char *
+build_cert_bag (unsigned char *buffer, size_t buflen, char *salt,
+                size_t *r_length)
+{
+  size_t len[9], needed;
+  unsigned char *p, *certbag;
+  size_t certbaglen;
+
+  /* Walk 9 steps down to collect the info: */
+
+  /* 8. The data goes into an octet string. */
+  needed = compute_tag_length (buflen);
+  needed += buflen;
+
+  /* 7. The algorithm identifier. */
+  needed += DIM (data_rc2iter2048);
+
+  /* 6. The data OID. */
+  needed += 2 + DIM (oid_data);
+
+  /* 5. A sequence. */
+  len[5] = needed;
+  needed += compute_tag_length ( needed);
+
+  /* 4. An integer. */
+  needed += 3;
+
+  /* 3. A sequence. */
+  len[3] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 2.  A [0] tag. */
+  len[2] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 1. The encryptedData OID. */
+  needed += 2 + DIM (oid_encryptedData);
+
+  /* 0. The first sequence. */
+  len[0] = needed;
+  needed += compute_tag_length (needed);
+
+  /* Now that we have all length information, allocate a buffer. */
+  p = certbag = gcry_malloc (needed);
+  if (!certbag)
+    {
+      log_error ("error allocating buffer\n");
+      return NULL;
+    }
+
+  /* Walk 9 steps up to store the data. */
+
+  /* 0. Store the first sequence. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[0]);
+
+  /* 1. Store the encryptedData OID. */
+  p = store_tag_length (p, TAG_OBJECT_ID, DIM (oid_encryptedData));
+  memcpy (p, oid_encryptedData, DIM (oid_encryptedData));
+  p += DIM (oid_encryptedData);
+
+  /* 2. Store a [0] tag. */
+  p = store_tag_length (p, 0xa0, len[2]);
+
+  /* 3. Store a sequence. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[3]);
+
+  /* 4. Store the integer 0. */
+  *p++ = TAG_INTEGER;
+  *p++ = 1;
+  *p++ = 0;
+
+  /* 5. Store a sequence. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[5]);
+
+  /* 6. Store the data OID. */
+  p = store_tag_length (p, TAG_OBJECT_ID, DIM (oid_data));
+  memcpy (p, oid_data, DIM (oid_data));
+  p += DIM (oid_data);
+
+  /* 7. Now for the pre-encoded algorithm identifier and the salt. */
+  memcpy (p, data_rc2iter2048, DIM (data_rc2iter2048));
+  memcpy (p + DATA_RC2ITER2048_SALT_OFF, salt, 8);
+  p += DIM (data_rc2iter2048);
+
+  /* 8. And finally the [0] tag with the encrypted data. */
+  p = store_tag_length (p, 0x80, buflen);
+  memcpy (p, buffer, buflen);
+  p += buflen;
+  certbaglen = p - certbag;
+
+  if (needed != certbaglen)
+    log_debug ("p12_parse: warning: length mismatch: %lu, %lu\n",
+               (unsigned long)needed, (unsigned long)certbaglen);
+
+  *r_length = certbaglen;
+  return certbag;
+}
+
+
+static unsigned char *
+build_cert_sequence (const unsigned char *buffer, size_t buflen,
+                     const unsigned char *sha1hash, const char *keyidstr,
+                     size_t *r_length)
+{
+  size_t len[8], needed, n;
+  unsigned char *p, *certseq;
+  size_t certseqlen;
+  int i;
+
+  log_assert (strlen (keyidstr) == 8);
+
+  /* Walk 8 steps down to collect the info: */
+
+  /* 7. The data goes into an octet string. */
+  needed = compute_tag_length (buflen);
+  needed += buflen;
+
+  /* 6. A [0] tag. */
+  len[6] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 5. An OID. */
+  needed += 2 + DIM (oid_x509Certificate_for_pkcs_12);
+
+  /* 4. A sequence. */
+  len[4] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 3. A [0] tag. */
+  len[3] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 2b. The attributes which are appended at the end. */
+  if (sha1hash)
+    needed += DIM (data_attrtemplate) + 20;
+
+  /* 2. An OID. */
+  needed += 2 + DIM (oid_pkcs_12_CertBag);
+
+  /* 1. A sequence. */
+  len[1] = needed;
+  needed += compute_tag_length (needed);
+
+  /* 0. The first sequence. */
+  len[0] = needed;
+  needed += compute_tag_length (needed);
+
+  /* Now that we have all length information, allocate a buffer. */
+  p = certseq = gcry_malloc (needed + 8 /*(for padding)*/);
+  if (!certseq)
+    {
+      log_error ("error allocating buffer\n");
+      return NULL;
+    }
+
+  /* Walk 8 steps up to store the data. */
+
+  /* 0. Store the first sequence. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[0]);
+
+  /* 1. Store the second sequence. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[1]);
+
+  /* 2. Store the pkcs12-cert-bag OID. */
+  p = store_tag_length (p, TAG_OBJECT_ID, DIM (oid_pkcs_12_CertBag));
+  memcpy (p, oid_pkcs_12_CertBag, DIM (oid_pkcs_12_CertBag));
+  p += DIM (oid_pkcs_12_CertBag);
+
+  /* 3. Store a [0] tag. */
+  p = store_tag_length (p, 0xa0, len[3]);
+
+  /* 4. Store a sequence. */
+  p = store_tag_length (p, TAG_SEQUENCE, len[4]);
+
+  /* 5. Store the x509Certificate OID. */
+  p = store_tag_length (p, TAG_OBJECT_ID,
+                        DIM (oid_x509Certificate_for_pkcs_12));
+  memcpy (p, oid_x509Certificate_for_pkcs_12,
+          DIM (oid_x509Certificate_for_pkcs_12));
+  p += DIM (oid_x509Certificate_for_pkcs_12);
+
+  /* 6. Store a [0] tag. */
+  p = store_tag_length (p, 0xa0, len[6]);
+
+  /* 7. And the octet string with the actual certificate. */
+  p = store_tag_length (p, TAG_OCTET_STRING, buflen);
+  memcpy (p, buffer, buflen);
+  p += buflen;
+
+  /* Append the attributes whose length we calculated at step 2b. */
+  if (sha1hash)
+    {
+      memcpy (p, data_attrtemplate, DIM (data_attrtemplate));
+      for (i=0; i < 8; i++)
+        p[DATA_ATTRTEMPLATE_KEYID_OFF+2*i+1] = keyidstr[i];
+      p += DIM (data_attrtemplate);
+      memcpy (p, sha1hash, 20);
+      p += 20;
+    }
+
+  certseqlen = p - certseq;
+  if (needed != certseqlen)
+    log_debug ("p12_parse: warning: length mismatch: %lu, %lu\n",
+               (unsigned long)needed, (unsigned long)certseqlen);
+
+  /* Append some pad characters; we already allocated extra space. */
+  n = 8 - certseqlen % 8;
+  for (i=0; i < n; i++, certseqlen++)
+    *p++ = n;
+
+  *r_length = certseqlen;
+  return certseq;
+}
+
+
+/* Expect the RSA key parameters in KPARMS and a password in PW.
+   Create a PKCS structure from it and return it as well as the length
+   in R_LENGTH; return NULL in case of an error.  If CHARSET is not
+   NULL, re-encode PW to that character set. */
+unsigned char *
+p12_build (gcry_mpi_t *kparms, const void *cert, size_t certlen,
+           const char *pw, const char *charset, size_t *r_length)
+{
+  unsigned char *buffer = NULL;
+  size_t n, buflen;
+  char salt[8];
+  struct buffer_s seqlist[3];
+  int seqlistidx = 0;
+  unsigned char sha1hash[20];
+  char keyidstr[8+1];
+  char *pwbuf = NULL;
+  size_t pwbufsize = 0;
+
+  n = buflen = 0; /* (avoid compiler warning). */
+  memset (sha1hash, 0, 20);
+  *keyidstr = 0;
+
+  if (charset && pw && *pw)
+    {
+      jnlib_iconv_t cd;
+      const char *inptr;
+      char *outptr;
+      size_t inbytes, outbytes;
+
+      /* We assume that the converted passphrase is at max 2 times
+         longer than its utf-8 encoding. */
+      pwbufsize = strlen (pw)*2 + 1;
+      pwbuf = gcry_malloc_secure (pwbufsize);
+      if (!pwbuf)
+        {
+          log_error ("out of secure memory while converting passphrase\n");
+          goto failure;
+        }
+
+      cd = jnlib_iconv_open (charset, "utf-8");
+      if (cd == (jnlib_iconv_t)(-1))
+        {
+          log_error ("can't convert passphrase to"
+                     " requested charset '%s': %s\n",
+                     charset, strerror (errno));
+          goto failure;
+        }
+
+      inptr = pw;
+      inbytes = strlen (pw);
+      outptr = pwbuf;
+      outbytes = pwbufsize - 1;
+      if ( jnlib_iconv (cd, (const char **)&inptr, &inbytes,
+                      &outptr, &outbytes) == (size_t)-1)
+        {
+          log_error ("error converting passphrase to"
+                     " requested charset '%s': %s\n",
+                     charset, strerror (errno));
+          jnlib_iconv_close (cd);
+          goto failure;
+        }
+      *outptr = 0;
+      jnlib_iconv_close (cd);
+      pw = pwbuf;
+    }
+
+
+  if (cert && certlen)
+    {
+      /* Calculate the hash value we need for the bag attributes. */
+      gcry_md_hash_buffer (GCRY_MD_SHA1, sha1hash, cert, certlen);
+      sprintf (keyidstr, "%02x%02x%02x%02x",
+               sha1hash[16], sha1hash[17], sha1hash[18], sha1hash[19]);
+
+      /* Encode the certificate. */
+      buffer = build_cert_sequence (cert, certlen, sha1hash, keyidstr,
+                                    &buflen);
+      if (!buffer)
+        goto failure;
+
+      /* Encrypt it. */
+      gcry_randomize (salt, 8, GCRY_STRONG_RANDOM);
+      crypt_block (buffer, buflen, salt, 8, 2048, NULL, 0, pw,
+                   GCRY_CIPHER_RFC2268_40, 1);
+
+      /* Encode the encrypted stuff into a bag. */
+      seqlist[seqlistidx].buffer = build_cert_bag (buffer, buflen, salt, &n);
+      seqlist[seqlistidx].length = n;
+      gcry_free (buffer);
+      buffer = NULL;
+      if (!seqlist[seqlistidx].buffer)
+        goto failure;
+      seqlistidx++;
+    }
+
+
+  if (kparms)
+    {
+      /* Encode the key. */
+      int i;
+
+      /* Right, that is a stupid way to distinguish ECC from RSA.  */
+      for (i=0; kparms[i]; i++)
+        ;
+
+      if (i == 3 && gcry_mpi_get_flag (kparms[0], GCRYMPI_FLAG_OPAQUE))
+        buffer = build_ecc_key_sequence (kparms, 0, &buflen);
+      else
+        buffer = build_rsa_key_sequence (kparms, 0, &buflen);
+      if (!buffer)
+        goto failure;
+
+      /* Encrypt it. */
+      gcry_randomize (salt, 8, GCRY_STRONG_RANDOM);
+      crypt_block (buffer, buflen, salt, 8, 2048, NULL, 0,
+                   pw, GCRY_CIPHER_3DES, 1);
+
+      /* Encode the encrypted stuff into a bag. */
+      if (cert && certlen)
+        seqlist[seqlistidx].buffer = build_key_bag (buffer, buflen, salt,
+                                                    sha1hash, keyidstr, &n);
+      else
+        seqlist[seqlistidx].buffer = build_key_bag (buffer, buflen, salt,
+                                                    NULL, NULL, &n);
+      seqlist[seqlistidx].length = n;
+      gcry_free (buffer);
+      buffer = NULL;
+      if (!seqlist[seqlistidx].buffer)
+        goto failure;
+      seqlistidx++;
+    }
+
+  seqlist[seqlistidx].buffer = NULL;
+  seqlist[seqlistidx].length = 0;
+
+  buffer = create_final (seqlist, pw, &buflen);
+
+ failure:
+  if (pwbuf)
+    {
+      /* Note that wipememory is not really needed due to the use of
+         gcry_malloc_secure.  */
+      wipememory (pwbuf, pwbufsize);
+      gcry_free (pwbuf);
+    }
+  for ( ; seqlistidx; seqlistidx--)
+    gcry_free (seqlist[seqlistidx].buffer);
+
+  *r_length = buffer? buflen : 0;
+  return buffer;
+}
+
+
+/* This is actually not a PKCS#12 function but one which creates an
+ * unencrypted PKCS#1 private key.  */
+unsigned char *
+p12_raw_build (gcry_mpi_t *kparms, int rawmode, size_t *r_length)
+{
+  unsigned char *buffer;
+  size_t buflen;
+  int i;
+
+  log_assert (rawmode == 1 || rawmode == 2);
+
+  /* Right, that is a stupid way to distinguish ECC from RSA.  */
+  for (i=0; kparms[i]; i++)
+    ;
+
+  if (gcry_mpi_get_flag (kparms[0], GCRYMPI_FLAG_OPAQUE))
+    buffer = build_ecc_key_sequence (kparms, rawmode, &buflen);
+  else
+    buffer = build_rsa_key_sequence (kparms, rawmode, &buflen);
+  if (!buffer)
+    return NULL;
+
+  *r_length = buflen;
+  return buffer;
+}