Initial revision

1 files changed, 1390 insertions, 0 deletions

diff --git a/pwmanager/libcrypt/cipher/ac.c b/pwmanager/libcrypt/cipher/ac.c
new file mode 100644
index 0000000..c18f243
--- a/dev/null
+++ b/pwmanager/libcrypt/cipher/ac.c
@@ -0,0 +1,1390 @@
+/* ac.c - Alternative interface for asymmetric cryptography.
+   Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+ 
+   This file is part of Libgcrypt.
+  
+   Libgcrypt is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser general Public License as
+   published by the Free Software Foundation; either version 2.1 of
+   the License, or (at your option) any later version.
+  
+   Libgcrypt 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 Lesser General Public License for more details.
+  
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include <config.h>
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <stddef.h>
+
+#include "g10lib.h"
+#include "cipher.h"
+
+
+
+/* At the moment the ac interface is a wrapper around the pk
+   interface, but this might change somewhen in the future, depending
+   on how much people prefer the ac interface.  */
+
+/* Mapping of flag numbers to the according strings as it is expected
+   for S-expressions.  */
+struct number_string
+{
+  int number;
+  const char *string;
+} gcry_ac_flags[] =
+  {
+    { GCRY_AC_FLAG_NO_BLINDING, "no-blinding" },
+    { 0, NULL },
+  };
+
+/* The positions in this list correspond to the values contained in
+   the gcry_ac_key_type_t enumeration list.  */
+static const char *ac_key_identifiers[] =
+  {
+    "private-key",
+    "public-key",
+  };
+
+/* These specifications are needed for key-pair generation; the caller
+   is allowed to pass additional, algorithm-specific `specs' to
+   gcry_ac_key_pair_generate.  This list is used for decoding the
+   provided values according to the selected algorithm.  */
+struct gcry_ac_key_generate_spec
+{
+  int algorithm;		/* Algorithm for which this flag is
+				   relevant.  */
+  const char *name;		/* Name of this flag.  */
+  size_t offset;		/* Offset in the cipher-specific spec
+				   structure at which the MPI value
+				   associated with this flag is to be
+				   found.  */
+} gcry_ac_key_generate_specs[] =
+  {
+    { GCRY_AC_RSA, "rsa-use-e", offsetof (gcry_ac_key_spec_rsa_t, e) },
+    { 0 },
+  };
+
+/* Handle structure.  */
+struct gcry_ac_handle
+{
+  int algorithm;		/* Algorithm ID associated with this
+				   handle.  */
+  const char *algorithm_name;	/* Name of the algorithm.  */
+  unsigned int flags;		/* Flags, not used yet.  */
+  gcry_module_t module;	        /* Reference to the algorithm
+				   module.  */
+};
+
+/* A named MPI value.  */
+typedef struct gcry_ac_mpi
+{
+  const char *name;		/* Name of MPI value. */
+  gcry_mpi_t mpi;		/* MPI value.         */
+  unsigned int flags;		/* Flags.             */
+} gcry_ac_mpi_t;
+
+/* A data set, that is simply a list of named MPI values.  */
+struct gcry_ac_data
+{
+  gcry_ac_mpi_t *data;		/* List of named values.      */
+  unsigned int data_n;		/* Number of values in DATA.  */
+};
+
+/* The key in `native' ac form and as an S-expression. */
+struct gcry_ac_key
+{
+  gcry_ac_data_t data;		/* Data in native ac structure.  */
+  gcry_sexp_t data_sexp;	/* Data as an S-expression.      */
+  gcry_ac_key_type_t type;	/* Type of the key.              */
+};
+
+/* Two keys.  */
+struct gcry_ac_key_pair
+{
+  gcry_ac_key_t public;
+  gcry_ac_key_t secret;
+};
+
+
+
+/*
+ * Primitive functions for the manipulation of `data sets'.
+ */
+
+/* Create a copy of the data set DATA and store it in DATA_CP.  */
+static gcry_err_code_t
+gcry_ac_data_copy_internal (gcry_ac_data_t *data_cp, gcry_ac_data_t data)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_ac_data_t data_new;
+  void *p = NULL;
+  int i = 0;
+
+  /* Allocate data set.  */
+  err = _gcry_malloc (sizeof (struct gcry_ac_data), 0, &p);
+  data_new = p;
+  if (! err)
+    data_new->data_n = data->data_n;
+
+  if (! err)
+    /* Allocate space for named MPIs.  */
+    err = _gcry_malloc (sizeof (gcry_ac_mpi_t) * data->data_n, 0,
+			(void **) &data_new->data);
+
+  if (! err)
+    {
+      /* Copy named MPIs.  */
+      
+      for (i = 0; i < data_new->data_n && (! err); i++)
+	{
+	  data_new->data[i].name = NULL;
+	  data_new->data[i].mpi = NULL;
+
+	  /* Name.  */
+	  data_new->data[i].name = strdup (data->data[i].name);
+	  if (! data_new->data[i].name)
+	    err = gpg_err_code_from_errno (errno);
+
+	  if (! err)
+	    {
+	      /* MPI.  */
+	      data_new->data[i].mpi = gcry_mpi_copy (data->data[i].mpi);
+	      if (! data_new->data[i].mpi)
+		err = gpg_err_code_from_errno (errno);
+	    }
+	}
+    }
+
+  if (! err)
+    {
+      /* Copy out.  */
+      *data_cp = data_new;
+    }
+  else
+    {
+      /* Deallocate resources.  */
+      if (data_new)
+	{
+	  if (data_new->data)
+	    {
+	      for (; i >= 0; i--)
+		{
+		  if (data_new->data[i].name)
+		    free ((void *) data_new->data[i].name);
+		  if (data_new->data[i].mpi)
+		    gcry_mpi_release (data_new->data[i].mpi);
+		}
+	      gcry_free (data_new->data);
+	    }
+	  gcry_free (data_new);
+	}
+    }
+
+  return err;
+}
+
+
+
+/* 
+ * Functions for converting data between the native ac and the
+ * S-expression structure.
+ */
+
+/* Extract the S-Expression DATA_SEXP into DATA under the control of
+   TYPE and NAME.  This function assumes that S-Expressions are of the
+   following structure:
+
+     (IDENTIFIER <data to be ignored>
+                 (ALGORITHM <list of named MPI values>))
+
+  IDENTIFIER is one of `private-key', `public-key', `enc-val',
+  `sig-val'; ALGORITHM is the name of the algorithm used.  */
+static gcry_err_code_t
+gcry_ac_data_extract (const char *identifier, const char *algorithm,
+		      gcry_sexp_t data_sexp, gcry_ac_data_t *data)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_sexp_t data_element_sexp = NULL;
+  gcry_sexp_t inner_data_sexp = NULL;
+  size_t inner_data_n;
+
+  const char *name;
+  size_t name_n;
+
+  gcry_mpi_t data_elem_mpi = NULL;
+  char *data_elem_name = NULL;
+
+  gcry_ac_data_t data_new = NULL;
+
+  int i = 0;
+
+  /* Verify that the S-expression contains the correct identifier.  */
+  name = gcry_sexp_nth_data (data_sexp, 0, &name_n);
+  if (! name)
+    err = GPG_ERR_INTERNAL;
+  else if (strncmp (identifier, name, name_n))
+    err = GPG_ERR_INTERNAL;
+
+  if (! err)
+    {
+      /* Extract inner S-expression.  */
+      inner_data_sexp = gcry_sexp_find_token (data_sexp, algorithm, 0);
+      if (! inner_data_sexp)
+	err = GPG_ERR_INTERNAL;
+      else
+	/* Count data elements, this includes the name of the
+	   algorithm.  */
+	inner_data_n = gcry_sexp_length (inner_data_sexp);
+    }
+
+  if (! err)
+    {
+      /* Allocate new data set.  */
+      data_new = gcry_malloc (sizeof (struct gcry_ac_data));
+      if (! data_new)
+	err = gpg_err_code_from_errno (errno);
+      else
+	{
+	  data_new->data = gcry_malloc (sizeof (gcry_ac_mpi_t)
+                                        * (inner_data_n - 1));
+	  if (! data_new->data)
+	    err = gpg_err_code_from_errno (errno);
+	}
+    }
+
+  if (! err)
+    {
+      /* Iterate through list of data elements and add them to the
+	 data set.  */
+
+      for (i = 1; i < inner_data_n; i++)
+	{
+	  data_new->data[i - 1].name = NULL;
+	  data_new->data[i - 1].mpi = NULL;
+
+	  /* Get the S-expression of the named MPI, that contains the
+	     name and the MPI value.  */
+	  data_element_sexp = gcry_sexp_nth (inner_data_sexp, i);
+	  if (! data_element_sexp)
+	    err = GPG_ERR_INTERNAL;
+
+	  if (! err)
+	    {
+	      /* Extract the name.  */
+	      name = gcry_sexp_nth_data (data_element_sexp, 0, &name_n);
+	      if (! name)
+		err = GPG_ERR_INTERNAL;
+	    }
+
+	  if (! err)
+	    {
+	      /* Extract the MPI value.  */
+	      data_elem_mpi = gcry_sexp_nth_mpi (data_element_sexp, 1,
+						 GCRYMPI_FMT_USG);
+	      if (! data_elem_mpi)
+		err = GPG_ERR_INTERNAL;
+	    }
+
+	  if (! err)
+	    {
+	      /* Duplicate the name.  */
+	      data_elem_name = gcry_malloc (name_n + 1);
+	      if (! data_elem_name)
+		
+		err = gpg_err_code_from_errno (errno);
+	      else
+		{
+		  strncpy (data_elem_name, name, name_n);
+		  data_elem_name[name_n] = 0;
+		}
+	    }
+
+	  /* Done.  */
+
+	  if (data_element_sexp)
+	    gcry_sexp_release (data_element_sexp);
+
+	  if (! err)
+	    {
+	      data_new->data[i - 1].name = data_elem_name;
+	      data_new->data[i - 1].mpi = data_elem_mpi;
+	    }
+	  else
+	    break;
+	}
+    }
+
+  if (! err)
+    {
+      /* Copy out.  */
+      data_new->data_n = inner_data_n - 1;
+      *data = data_new;
+    }
+  else
+    {
+      /* Deallocate resources.  */
+
+      if (data_new)
+	{
+	  if (data_new->data)
+	    {
+	      int j;
+	     
+	      for (j = 0; j < i - 1; j++)
+		{
+		  if (data_new->data[j].name)
+		    gcry_free ((void *) data_new->data[j].name);
+		  if (data_new->data[j].mpi)
+		    gcry_mpi_release (data_new->data[j].mpi);
+		}
+
+	      gcry_free (data_new->data);
+	    }
+	  gcry_free (data_new);
+	}
+    }
+
+  return err;
+}
+
+/* Construct an S-expression from the DATA and store it in
+   DATA_SEXP. The S-expression will be of the following structure:
+
+     (IDENTIFIER [(flags [...])]
+                 (ALGORITHM <list of named MPI values>))  */
+static gcry_err_code_t
+gcry_ac_data_construct (const char *identifier, int include_flags,
+			unsigned int flags, const char *algorithm,
+			gcry_ac_data_t data, gcry_sexp_t *data_sexp)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  void **arg_list = NULL;
+
+  gcry_sexp_t data_sexp_new = NULL;
+
+  size_t data_format_n = 0;
+  char *data_format = NULL;
+
+  int i;
+
+  /* We build a list of arguments to pass to
+     gcry_sexp_build_array().  */
+  arg_list = gcry_malloc (sizeof (void *) * data->data_n);
+  if (! arg_list)
+    err = gpg_err_code_from_errno (errno);
+  else
+    /* Fill list with MPIs.  */
+    for (i = 0; i < data->data_n; i++)
+      arg_list[i] = (void *) &data->data[i].mpi;
+
+  if (! err)
+    {
+      /* Calculate size of format string.  */
+
+      data_format_n = (5 + (include_flags ? 7 : 0)
+                       + strlen (identifier) + strlen (algorithm));
+
+      for (i = 0; i < data->data_n; i++)
+        {
+          /* Per-element sizes.  */
+          data_format_n += 4 + strlen (data->data[i].name);
+        }
+
+      if (include_flags)
+        {
+          /* Add flags.  */
+          for (i = 0; gcry_ac_flags[i].number; i++)
+            if (flags & gcry_ac_flags[i].number)
+              data_format_n += strlen (gcry_ac_flags[i].string) + 1;
+        }
+
+      /* Done.  */
+      data_format = gcry_malloc (data_format_n);
+      if (! data_format)
+	err = gpg_err_code_from_errno (errno);
+    }
+
+  if (! err)
+    {
+      /* Construct the format string.  */
+
+      *data_format = 0;
+      strcat (data_format, "(");
+      strcat (data_format, identifier);
+      if (include_flags)
+	{
+	  strcat (data_format, "(flags");
+	  for (i = 0; gcry_ac_flags[i].number; i++)
+	    if (flags & gcry_ac_flags[i].number)
+	      {
+		strcat (data_format, " ");
+		strcat (data_format, gcry_ac_flags[i].string);
+	      }
+	  strcat (data_format, ")");
+	}
+      strcat (data_format, "(");
+      strcat (data_format, algorithm);
+      for (i = 0; i < data->data_n; i++)
+	{
+	  strcat (data_format, "(");
+	  strcat (data_format, data->data[i].name);
+	  strcat (data_format, "%m)");
+	}
+      strcat (data_format, "))");
+
+      /* Create final S-expression.  */
+      err = gcry_sexp_build_array (&data_sexp_new, NULL,
+				   data_format, arg_list);
+    }
+
+  if (err)
+    {
+      /* Deallocate resources.  */
+
+      if (arg_list)
+	gcry_free (arg_list);
+      if (data_format)
+	gcry_free (data_format);
+      if (data_sexp_new)
+	gcry_sexp_release (data_sexp_new);
+    }
+
+  else
+    /* Copy-out.  */
+    *data_sexp = data_sexp_new;
+
+  return err;
+}
+
+
+
+/* 
+ * Functions for working with data sets.
+ */
+
+/* Creates a new, empty data set and stores it in DATA.  */
+gcry_error_t
+gcry_ac_data_new (gcry_ac_data_t *data)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_ac_data_t data_new = NULL;
+
+  data_new = gcry_malloc (sizeof (struct gcry_ac_data));
+  if (! data_new)
+    err = gpg_err_code_from_errno (errno);
+
+  if (! err)
+    {
+      data_new->data = NULL;
+      data_new->data_n = 0;
+      *data = data_new;
+    }
+
+  return gcry_error (err);
+}
+
+/* Destroys the data set DATA.  */
+void
+gcry_ac_data_destroy (gcry_ac_data_t data)
+{
+  int i;
+
+  for (i = 0; i < data->data_n; i++)
+    {
+      gcry_free ((void *) data->data[i].name);
+      gcry_mpi_release (data->data[i].mpi);
+    }
+  gcry_free (data->data);
+  gcry_free (data);
+}
+
+/* Add the value MPI to DATA with the label NAME.  If FLAGS contains
+   GCRY_AC_FLAG_DATA_COPY, the data set will contain copies of NAME
+   and MPI.  If FLAGS contains GCRY_AC_FLAG_DATA_DEALLOC or
+   GCRY_AC_FLAG_DATA_COPY, the values contained in the data set will
+   be deallocated when they are to be removed from the data set.  */
+gcry_error_t
+gcry_ac_data_set (gcry_ac_data_t data, unsigned int flags,
+		  const char *name, gcry_mpi_t mpi)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_ac_mpi_t *ac_mpi = NULL;
+  gcry_mpi_t mpi_add = NULL;
+  char *name_add = NULL;
+  unsigned int i = 0;
+
+  if (flags & ~(GCRY_AC_FLAG_DEALLOC | GCRY_AC_FLAG_COPY))
+    err = GPG_ERR_INV_ARG;
+  else
+    {
+      if (flags & GCRY_AC_FLAG_COPY)
+	{
+	  /* Create copies.  */
+
+	  name_add = strdup (name);
+	  if (! name_add)
+	    err = GPG_ERR_ENOMEM;
+	  if (! err)
+	    {
+	      mpi_add = gcry_mpi_copy (mpi);
+	      if (! mpi_add)
+		err = GPG_ERR_ENOMEM;
+	    }
+	}
+      else
+	{
+	  name_add = (char *) name;
+	  mpi_add = mpi;
+	}
+      
+      /* Search for existing entry.  */
+      for (i = 0; (i < data->data_n) && (! ac_mpi); i++)
+	if (! strcmp (name, data->data[i].name))
+	  ac_mpi = data->data + i;
+      
+      if (ac_mpi)
+	{
+	  /* An entry for NAME does already exist.  */
+	  if (ac_mpi->flags & GCRY_AC_FLAG_DEALLOC)
+	    {
+	      /* Deallocate old values.  */
+	      gcry_free ((char *) ac_mpi->name);
+	      gcry_mpi_release (ac_mpi->mpi);
+	    }
+	}
+      else
+	{
+	  /* Create a new entry.  */
+	  
+	  gcry_ac_mpi_t *ac_mpis = NULL;
+	  
+	  ac_mpis = realloc (data->data, sizeof (*data->data) * (data->data_n + 1));
+	  if (! ac_mpis)
+	    err = gpg_err_code_from_errno (errno);
+	  
+	  if (data->data != ac_mpis)
+	    data->data = ac_mpis;
+	  ac_mpi = data->data + data->data_n;
+	  data->data_n++;
+	}
+      
+      ac_mpi->flags = flags;
+      ac_mpi->name = name_add;
+      ac_mpi->mpi = mpi_add;
+    }
+
+  return gcry_error (err);
+}
+
+/* Create a copy of the data set DATA and store it in DATA_CP.  */
+gcry_error_t
+gcry_ac_data_copy (gcry_ac_data_t *data_cp, gcry_ac_data_t data)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+
+  err = gcry_ac_data_copy_internal (data_cp, data);
+
+  return gcry_error (err);
+}
+
+/* Returns the number of named MPI values inside of the data set
+   DATA.  */
+unsigned int
+gcry_ac_data_length (gcry_ac_data_t data)
+{
+  return data->data_n;
+}
+
+/* Store the value labelled with NAME found in DATA in MPI.  If FLAGS
+   contains GCRY_AC_FLAG_COPY, store a copy of the MPI value contained
+   in the data set.  MPI may be NULL.  */
+gcry_error_t
+gcry_ac_data_get_name (gcry_ac_data_t data, unsigned int flags,
+		       const char *name, gcry_mpi_t *mpi)
+{
+  gcry_err_code_t err = GPG_ERR_NO_DATA;
+  gcry_mpi_t mpi_found = NULL;
+  unsigned int i = 0;
+
+  if (flags & ~(GCRY_AC_FLAG_COPY))
+    err = GPG_ERR_INV_ARG;
+  else
+    {
+      for (i = 0; i < data->data_n && (! mpi_found); i++)
+	if (! strcmp (data->data[i].name, name))
+	  {
+	    if (flags & GCRY_AC_FLAG_COPY)
+	      {
+		mpi_found = gcry_mpi_copy (data->data[i].mpi);
+		if (! mpi_found)
+		  err = GPG_ERR_ENOMEM;
+	      }
+	    else
+	      mpi_found = data->data[i].mpi;
+	    
+	    if (mpi_found)
+	      err = GPG_ERR_NO_ERROR;
+	  }
+    }
+
+  if (! err)
+    if (mpi)
+      *mpi = mpi_found;
+
+  return gcry_error (err);
+}
+
+/* Stores in NAME and MPI the named MPI value contained in the data
+   set DATA with the index IDX.  If FLAGS contains GCRY_AC_FLAG_COPY,
+   store copies of the values contained in the data set. NAME or MPI
+   may be NULL.  */
+gcry_error_t
+gcry_ac_data_get_index (gcry_ac_data_t data, unsigned int flags, unsigned int idx,
+			const char **name, gcry_mpi_t *mpi)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_mpi_t mpi_return = NULL;
+  char *name_return = NULL;
+
+  if (flags & ~(GCRY_AC_FLAG_COPY))
+    err = GPG_ERR_INV_ARG;
+  else
+    {
+      if (idx < data->data_n)
+	{
+	  if (flags & GCRY_AC_FLAG_COPY)
+	    {
+	      /* Return copies to the user.  */
+	      if (name)
+		name_return = strdup (data->data[idx].name);
+	      if (mpi)
+		mpi_return = gcry_mpi_copy (data->data[idx].mpi);
+	      
+	      if (! (name_return && mpi_return))
+		{
+		  if (name_return)
+		    free (name_return);
+		  if (mpi_return)
+		    gcry_mpi_release (mpi_return);
+		  err = GPG_ERR_ENOMEM;
+		}
+	    }
+	  else
+	    {
+	      name_return = (char *) data->data[idx].name;
+	      mpi_return = data->data[idx].mpi;
+	    }
+	}
+      else
+	err = GPG_ERR_NO_DATA;
+    }
+
+  if (! err)
+    {
+      if (name)
+	*name = name_return;
+      if (mpi)
+	*mpi = mpi_return;
+    }
+
+  return gcry_error (err);
+}
+
+/* Destroys any values contained in the data set DATA.  */
+void
+gcry_ac_data_clear (gcry_ac_data_t data)
+{
+  gcry_free (data->data);
+  data->data = NULL;
+  data->data_n = 0;
+}
+
+
+
+/*
+ * Handle management.
+ */
+
+/* Creates a new handle for the algorithm ALGORITHM and store it in
+   HANDLE.  FLAGS is not used yet.  */
+gcry_error_t
+gcry_ac_open (gcry_ac_handle_t *handle,
+	      gcry_ac_id_t algorithm, unsigned int flags)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_module_t module = NULL;
+  gcry_ac_handle_t handle_new;
+  const char *algorithm_name;
+
+  *handle = NULL;
+
+  /* Get name.  */
+  algorithm_name = _gcry_pk_aliased_algo_name (algorithm);
+  if (! *algorithm_name)
+    err = GPG_ERR_PUBKEY_ALGO;
+
+  if (! err)  /* Acquire reference to the pubkey module.  */
+    err = _gcry_pk_module_lookup (algorithm, &module);
+  
+  if (! err)
+    {
+      /* Allocate.  */
+      handle_new = gcry_malloc (sizeof (struct gcry_ac_handle));
+      if (! handle_new)
+	err = gpg_err_code_from_errno (errno);
+    }
+
+  if (! err)
+    {
+      /* Done.  */
+      handle_new->algorithm = algorithm;
+      handle_new->algorithm_name = algorithm_name;
+      handle_new->flags = flags;
+      handle_new->module = module;
+      *handle = handle_new;
+    }
+  else
+    {
+      /* Deallocate resources.  */
+      if (module)
+	_gcry_pk_module_release (module);
+    }
+
+  return gcry_error (err);
+}
+
+/* Destroys the handle HANDLE.  */
+void
+gcry_ac_close (gcry_ac_handle_t handle)
+{
+  /* Release reference to pubkey module.  */
+  if (handle)
+    {
+      _gcry_pk_module_release (handle->module);
+      gcry_free (handle);
+    }
+}
+
+
+
+/* 
+ * Key management.
+ */
+
+/* Creates a new key of type TYPE, consisting of the MPI values
+   contained in the data set DATA and stores it in KEY.  */
+gcry_error_t
+gcry_ac_key_init (gcry_ac_key_t *key,
+		  gcry_ac_handle_t handle,
+		  gcry_ac_key_type_t type,
+		  gcry_ac_data_t data)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_ac_data_t data_new = NULL;
+  gcry_sexp_t data_sexp = NULL;
+  gcry_ac_key_t key_new = NULL;
+
+  /* Allocate.  */
+  key_new = gcry_malloc (sizeof (struct gcry_ac_key));
+  if (! key_new)
+    err = gpg_err_code_from_errno (errno);
+
+  if (! err)
+    {
+      /* Create S-expression from data set.  */
+      err = gcry_ac_data_construct (ac_key_identifiers[type], 0, 0,
+                                    handle->algorithm_name, data, &data_sexp);
+    }
+
+  if (! err)
+    {
+      /* Copy data set.  */
+      err = gcry_ac_data_copy_internal (&data_new, data);
+    }
+
+  if (! err)
+    {
+      /* Done.  */
+      key_new->data_sexp = data_sexp;
+      key_new->data = data_new;
+      key_new->type = type;
+      *key = key_new;
+    }
+  else
+    {
+      /* Deallocate resources.  */
+      if (key_new)
+	gcry_free (key_new);
+      if (data_sexp)
+	gcry_sexp_release (data_sexp);
+    }
+
+  return gcry_error (err);
+}
+
+/* Generates a new key pair via the handle HANDLE of NBITS bits and
+   stores it in KEY_PAIR.  In case non-standard settings are wanted, a
+   pointer to a structure of type gcry_ac_key_spec_<algorithm>_t,
+   matching the selected algorithm, can be given as KEY_SPEC.
+   MISC_DATA is not used yet.  */
+gcry_error_t
+gcry_ac_key_pair_generate (gcry_ac_handle_t handle, unsigned int nbits, void *key_spec,
+			   gcry_ac_key_pair_t *key_pair, gcry_mpi_t **misc_data)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+
+  gcry_ac_key_pair_t key_pair_new = NULL;
+
+  gcry_sexp_t genkey_sexp_request = NULL;
+  gcry_sexp_t genkey_sexp_reply = NULL;
+
+  char *genkey_format = NULL;
+  size_t genkey_format_n = 0;
+
+  void **arg_list = NULL;
+  size_t arg_list_n = 0;
+
+  unsigned int i = 0;
+
+  /* Allocate key pair.  */
+  key_pair_new = gcry_malloc (sizeof (struct gcry_ac_key_pair));
+  if (! key_pair_new)
+    err = gpg_err_code_from_errno (errno);
+
+  if (! err)
+    {
+      /* Allocate keys.  */
+      key_pair_new->secret = gcry_malloc (sizeof (struct gcry_ac_key));
+      key_pair_new->public = gcry_malloc (sizeof (struct gcry_ac_key));
+
+      if (! (key_pair_new->secret || key_pair_new->public))
+ 	err = gpg_err_code_from_errno (errno);
+      else
+	{
+	  key_pair_new->secret->type = GCRY_AC_KEY_SECRET;
+	  key_pair_new->public->type = GCRY_AC_KEY_PUBLIC;
+	  key_pair_new->secret->data_sexp = NULL;
+	  key_pair_new->public->data_sexp = NULL;
+	  key_pair_new->secret->data = NULL;
+	  key_pair_new->public->data = NULL;
+	}
+    }
+
+  if (! err)
+    {
+      /* Calculate size of the format string, that is used for
+	 creating the request S-expression.  */
+      genkey_format_n = 23;
+
+      /* Respect any relevant algorithm specific commands.  */
+      if (key_spec)
+	for (i = 0; gcry_ac_key_generate_specs[i].algorithm; i++)
+	  if (handle->algorithm == gcry_ac_key_generate_specs[i].algorithm)
+	    genkey_format_n += 6;
+
+      /* Create format string.  */
+      genkey_format = gcry_malloc (genkey_format_n);
+      if (! genkey_format)
+	err = gpg_err_code_from_errno (errno);
+      else
+	{
+	  /* Fill format string.  */
+	  *genkey_format = 0;
+	  strcat (genkey_format, "(genkey(%s(nbits%d)");
+	  if (key_spec)
+	    for (i = 0; gcry_ac_key_generate_specs[i].algorithm; i++)
+	      if (handle->algorithm == gcry_ac_key_generate_specs[i].algorithm)
+		strcat (genkey_format, "(%s%m)");
+	  strcat (genkey_format, "))");
+	}
+    }
+
+  if (! err)
+    {
+      /* Build list of argument pointers, the algorithm name and the
+	 nbits are needed always.  */
+      arg_list_n = 2;
+
+      /* Now the algorithm specific arguments.  */
+      if (key_spec)
+	for (i = 0; gcry_ac_key_generate_specs[i].algorithm; i++)
+	  if (handle->algorithm == gcry_ac_key_generate_specs[i].algorithm)
+	    arg_list_n += 2;
+
+      /* Allocate list.  */
+      arg_list = gcry_malloc (sizeof (void *) * arg_list_n);
+      if (! arg_list)
+	err = gpg_err_code_from_errno (errno);
+      else
+	{
+	  /* Fill argument list. */
+	  
+	  int j;
+
+	  arg_list[0] = (void *) &handle->algorithm_name;
+	  arg_list[1] = (void *) &nbits;
+
+	  if (key_spec)
+	    for (j = 2, i = 0; gcry_ac_key_generate_specs[i].algorithm; i++)
+	      if (handle->algorithm == gcry_ac_key_generate_specs[i].algorithm)
+		{
+		  /* Add name of this specification flag and the
+		     according member of the spec strucuture.  */
+		  arg_list[j++] = (void *)(&gcry_ac_key_generate_specs[i].name);
+		  arg_list[j++] = (void *)
+                                  (((char *) key_spec)
+                                   + gcry_ac_key_generate_specs[i].offset);
+		}
+	}
+    }
+
+  if (! err)
+    /* Construct final request S-expression.  */
+    err = gcry_err_code (gcry_sexp_build_array (&genkey_sexp_request, NULL,
+					       genkey_format, arg_list));
+
+  if (! err)
+    /* Perform genkey operation.  */
+    err = gcry_err_code (gcry_pk_genkey (&genkey_sexp_reply,
+					genkey_sexp_request));
+
+  /* Split keys.  */
+  if (! err)
+    {
+      key_pair_new->secret->data_sexp = gcry_sexp_find_token (genkey_sexp_reply,
+							      "private-key", 0);
+      if (! key_pair_new->secret->data_sexp)
+	err = GPG_ERR_INTERNAL;
+    }
+  if (! err)
+    {
+      key_pair_new->public->data_sexp = gcry_sexp_find_token (genkey_sexp_reply,
+							      "public-key", 0);
+      if (! key_pair_new->public->data_sexp)
+	err = GPG_ERR_INTERNAL;
+    }
+
+  /* Extract key material.  */
+  if (! err)
+    err = gcry_ac_data_extract ("private-key", handle->algorithm_name,
+				key_pair_new->secret->data_sexp,
+				&key_pair_new->secret->data);
+  if (! err)
+    err = gcry_ac_data_extract ("public-key", handle->algorithm_name,
+				key_pair_new->public->data_sexp,
+				&key_pair_new->public->data);
+
+  /* Done.  */
+
+  if (! err)
+    *key_pair = key_pair_new;
+  else
+    {
+      /* Deallocate resources.  */
+
+      if (key_pair_new)
+	{
+	  if (key_pair_new->secret)
+	    gcry_ac_key_destroy (key_pair_new->secret);
+	  if (key_pair_new->public)
+	    gcry_ac_key_destroy (key_pair_new->public);
+
+	  gcry_free (key_pair_new);
+	}
+
+      if (arg_list)
+	gcry_free (arg_list);
+
+      if (genkey_format)
+	gcry_free (genkey_format);
+
+      if (genkey_sexp_request)
+	gcry_sexp_release (genkey_sexp_request);
+      if (genkey_sexp_reply)
+	gcry_sexp_release (genkey_sexp_reply);
+    }
+
+  return gcry_error (err);
+}
+
+/* Returns the key of type WHICH out of the key pair KEY_PAIR.  */
+gcry_ac_key_t
+gcry_ac_key_pair_extract (gcry_ac_key_pair_t key_pair,
+			  gcry_ac_key_type_t witch)
+{
+  gcry_ac_key_t key = NULL;
+
+  switch (witch)
+    {
+    case GCRY_AC_KEY_SECRET:
+      key = key_pair->secret;
+      break;
+
+    case GCRY_AC_KEY_PUBLIC:
+      key = key_pair->public;
+      break;
+    }
+
+  return key;
+}
+
+/* Destroys the key KEY.  */
+void
+gcry_ac_key_destroy (gcry_ac_key_t key)
+{
+  int i;
+
+  if (key)
+    {
+      if (key->data)
+        {
+          for (i = 0; i < key->data->data_n; i++)
+            if (key->data->data[i].mpi != NULL)
+              gcry_mpi_release (key->data->data[i].mpi);
+          gcry_free (key->data);
+        }
+      if (key->data_sexp)
+        gcry_sexp_release (key->data_sexp);
+      gcry_free (key);
+    }
+}
+
+/* Destroys the key pair KEY_PAIR.  */
+void
+gcry_ac_key_pair_destroy (gcry_ac_key_pair_t key_pair)
+{
+  if (key_pair)
+    {
+      gcry_ac_key_destroy (key_pair->secret);
+      gcry_ac_key_destroy (key_pair->public);
+      gcry_free (key_pair);
+    }
+}
+
+/* Returns the data set contained in the key KEY.  */
+gcry_ac_data_t
+gcry_ac_key_data_get (gcry_ac_key_t key)
+{
+  return  key->data;
+}
+
+/* Verifies that the key KEY is sane via HANDLE.  */
+gcry_error_t
+gcry_ac_key_test (gcry_ac_handle_t handle, gcry_ac_key_t key)
+{
+  gcry_err_code_t err;
+
+  err = gcry_err_code (gcry_pk_testkey (key->data_sexp));
+
+  return gcry_error (err);
+}
+
+/* Stores the number of bits of the key KEY in NBITS via HANDLE.  */
+gcry_error_t
+gcry_ac_key_get_nbits (gcry_ac_handle_t handle, gcry_ac_key_t key, unsigned int *nbits)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  unsigned int n;
+
+  n = gcry_pk_get_nbits (key->data_sexp);
+  if (n)
+    *nbits = n;
+  else
+    err = GPG_ERR_PUBKEY_ALGO;
+
+  return gcry_error (err);
+}
+
+/* Writes the 20 byte long key grip of the key KEY to KEY_GRIP via
+   HANDLE.  */
+gcry_error_t
+gcry_ac_key_get_grip (gcry_ac_handle_t handle, gcry_ac_key_t key, unsigned char *key_grip)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  unsigned char *ret;
+
+  ret = gcry_pk_get_keygrip (key->data_sexp, key_grip);
+  if (! ret)
+    err = GPG_ERR_INV_OBJ;
+
+  return gcry_error (err);
+}
+
+
+
+/* 
+ * Functions performing cryptographic operations.
+ */
+
+/* Encrypts the plain text MPI value DATA_PLAIN with the key public
+   KEY under the control of the flags FLAGS and stores the resulting
+   data set into DATA_ENCRYPTED.  */
+gcry_error_t
+gcry_ac_data_encrypt (gcry_ac_handle_t handle,
+		      unsigned int flags,
+		      gcry_ac_key_t key,
+		      gcry_mpi_t data_plain,
+		      gcry_ac_data_t *data_encrypted)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_sexp_t sexp_request = NULL;
+  gcry_sexp_t sexp_reply = NULL;
+  char *request_format = NULL;
+  size_t request_format_n = 0;
+  gcry_ac_data_t data;
+  
+  int i;
+
+  if (key->type != GCRY_AC_KEY_PUBLIC)
+    err = GPG_ERR_WRONG_KEY_USAGE;
+
+  if (! err)
+    {
+      /* Calculate request format string.  */
+
+      request_format_n += 23;
+      for (i = 0; gcry_ac_flags[i].number; i++)
+	if (flags & gcry_ac_flags[i].number)
+	  request_format_n += strlen (gcry_ac_flags[i].string) + 1;
+
+      /* Allocate request format string.  */
+      request_format = gcry_malloc (request_format_n);
+      if (! request_format)
+	err = gpg_err_code_from_errno (errno);
+    }
+
+  if (! err)
+    {
+      /* Fill format string.  */
+      *request_format = 0;
+      strcat (request_format, "(data(flags");
+      for (i = 0; gcry_ac_flags[i].number; i++)
+	if (flags & gcry_ac_flags[i].number)
+	  {
+	    strcat (request_format, " ");
+	    strcat (request_format, gcry_ac_flags[i].string);
+	  }
+      strcat (request_format, ")(value%m))");
+
+      /* Create S-expression.  */
+      err = gcry_sexp_build (&sexp_request, NULL,
+			     request_format, data_plain);
+    }
+
+  if (! err)
+    /* Encrypt.  */
+    err = gcry_pk_encrypt (&sexp_reply, sexp_request, key->data_sexp);
+
+  if (! err)
+    /* Extract data.  */
+    err = gcry_ac_data_extract ("enc-val", handle->algorithm_name,
+				sexp_reply, &data);
+
+  /* Deallocate resources.  */
+
+  if (sexp_request)
+    gcry_sexp_release (sexp_request);
+  if (sexp_reply)
+    gcry_sexp_release (sexp_reply);
+
+  if (! err)
+    /* Copy out.  */
+    *data_encrypted = data;
+
+  return gcry_error (err);
+}
+
+/* Decrypts the encrypted data contained in the data set
+   DATA_ENCRYPTED with the secret key KEY under the control of the
+   flags FLAGS and stores the resulting plain text MPI value in
+   DATA_PLAIN.  */
+gcry_error_t
+gcry_ac_data_decrypt (gcry_ac_handle_t handle,
+		      unsigned int flags,
+		      gcry_ac_key_t key,
+		      gcry_mpi_t *data_plain,
+		      gcry_ac_data_t data_encrypted)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_mpi_t data_decrypted = NULL;
+  gcry_sexp_t sexp_request = NULL;
+  gcry_sexp_t sexp_reply = NULL;
+
+  if (key->type != GCRY_AC_KEY_SECRET)
+    err = GPG_ERR_WRONG_KEY_USAGE;
+
+  if (! err)
+    /* Create S-expression from data.  */
+    err = gcry_ac_data_construct ("enc-val", 1, flags, handle->algorithm_name,
+				  data_encrypted, &sexp_request);
+
+  if (! err)
+    /* Decrypt.  */
+    err = gcry_pk_decrypt (&sexp_reply, sexp_request, key->data_sexp);
+
+  if (! err)
+    {
+      /* Extract plain text. */
+
+      gcry_sexp_t l;
+
+      l = gcry_sexp_find_token (sexp_reply, "value", 0);
+      if (! l)
+	err = GPG_ERR_GENERAL;
+      else
+	{
+	  data_decrypted = gcry_sexp_nth_mpi (l, 1, GCRYMPI_FMT_USG);
+	  if (! data_decrypted)
+	    err = GPG_ERR_GENERAL;
+	  gcry_sexp_release (l);
+	}
+    }
+
+  /* Done.  */
+
+  if (err)
+    {
+      /* Deallocate resources.  */
+      if (sexp_request)
+	gcry_sexp_release (sexp_request);
+      if (sexp_reply)
+	gcry_sexp_release (sexp_reply);
+    }
+  else
+    *data_plain = data_decrypted;
+
+  return gcry_error (err);
+
+}
+
+/* Signs the data contained in DATA with the secret key KEY and stores
+   the resulting signature data set in DATA_SIGNATURE.  */
+gcry_error_t
+gcry_ac_data_sign (gcry_ac_handle_t handle,
+		   gcry_ac_key_t key,
+		   gcry_mpi_t data,
+		   gcry_ac_data_t *data_signature)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_sexp_t sexp_request = NULL;
+  gcry_sexp_t sexp_reply = NULL;
+  gcry_ac_data_t ac_data;
+
+  if (key->type != GCRY_AC_KEY_SECRET)
+    err = GPG_ERR_WRONG_KEY_USAGE;
+
+  if (! err)
+    /* Create S-expression holding the data.  */
+    err = gcry_sexp_build (&sexp_request, NULL,
+			   "(data(flags)(value%m))", data);
+  if (! err)
+    /* Sign.  */
+    err = gcry_pk_sign (&sexp_reply, sexp_request, key->data_sexp);
+
+  if (! err)
+    /* Extract data.  */
+    err = gcry_ac_data_extract ("sig-val", handle->algorithm_name,
+				sexp_reply, &ac_data);
+
+  /* Done.  */
+
+  if (sexp_request)
+    gcry_sexp_release (sexp_request);
+  if (sexp_reply)
+    gcry_sexp_release (sexp_reply);
+
+  if (! err)
+    *data_signature = ac_data;
+
+  return gcry_error (err);
+}
+
+/* Verifies that the signature contained in the data set
+   DATA_SIGNATURE is indeed the result of signing the data contained
+   in DATA with the secret key belonging to the public key KEY.  */
+gcry_error_t
+gcry_ac_data_verify (gcry_ac_handle_t handle,
+		     gcry_ac_key_t key,
+		     gcry_mpi_t data,
+		     gcry_ac_data_t data_signature)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  gcry_sexp_t sexp_request = NULL;
+  gcry_sexp_t sexp_data = NULL;
+
+  if (key->type != GCRY_AC_KEY_PUBLIC)
+    err = GPG_ERR_WRONG_KEY_USAGE;
+
+  if (! err)
+    /* Construct S-expression holding the signature data.  */
+    err = gcry_ac_data_construct ("sig-val", 1, 0, handle->algorithm_name,
+				  data_signature, &sexp_request);
+
+  if (! err)
+    /* Construct S-expression holding the data.  */
+    err = gcry_sexp_build (&sexp_data, NULL,
+			   "(data(flags)(value%m))", data);
+
+  if (! err)
+    /* Verify signature.  */
+    err = gcry_pk_verify (sexp_request, sexp_data, key->data_sexp);
+
+  /* Done.  */
+
+  if (sexp_request)
+    gcry_sexp_release (sexp_request);
+  if (sexp_data)
+    gcry_sexp_release (sexp_data);
+
+  return gcry_error (err);
+}
+
+
+
+/* 
+ * General functions.
+ */
+
+/* Stores the textual representation of the algorithm whose id is
+   given in ALGORITHM in NAME.  */
+gcry_error_t
+gcry_ac_id_to_name (gcry_ac_id_t algorithm, const char **name)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  const char *n;
+
+  n = gcry_pk_algo_name (algorithm);
+  if (*n)
+    *name = n;
+  else
+    err = GPG_ERR_PUBKEY_ALGO;
+
+  return gcry_error (err);
+}
+
+/* Stores the numeric ID of the algorithm whose textual representation
+   is contained in NAME in ALGORITHM.  */
+gcry_error_t
+gcry_ac_name_to_id (const char *name, gcry_ac_id_t *algorithm)
+{
+  gcry_err_code_t err = GPG_ERR_NO_ERROR;
+  int algo;
+
+  algo = gcry_pk_map_name (name);
+  if (algo)
+    *algorithm = algo;
+  else
+    err = GPG_ERR_PUBKEY_ALGO;
+    
+  return gcry_error (err);
+}