Adding upstream version 2.2.27.upstream/2.2.27upstream

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

1 files changed, 987 insertions, 0 deletions

diff --git a/g10/keyid.c b/g10/keyid.c
new file mode 100644
index 0000000..69d85da
--- /dev/null
+++ b/g10/keyid.c
@@ -0,0 +1,987 @@
+/* keyid.c - key ID and fingerprint handling
+ * Copyright (C) 1998, 1999, 2000, 2001, 2003,
+ *               2004, 2006, 2010 Free Software Foundation, Inc.
+ * Copyright (C) 2014 Werner Koch
+ * Copyright (C) 2016 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/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <time.h>
+
+#include "gpg.h"
+#include "../common/util.h"
+#include "main.h"
+#include "packet.h"
+#include "options.h"
+#include "keydb.h"
+#include "../common/i18n.h"
+#include "rmd160.h"
+#include "../common/host2net.h"
+
+
+#define KEYID_STR_SIZE 19
+
+#ifdef HAVE_UNSIGNED_TIME_T
+# define IS_INVALID_TIME_T(a) ((a) == (time_t)(-1))
+#else
+  /* Error or 32 bit time_t and value after 2038-01-19.  */
+# define IS_INVALID_TIME_T(a) ((a) < 0)
+#endif
+
+
+/* Return a letter describing the public key algorithms.  */
+int
+pubkey_letter( int algo )
+{
+  switch (algo)
+    {
+    case PUBKEY_ALGO_RSA:	return 'R' ;
+    case PUBKEY_ALGO_RSA_E:	return 'r' ;
+    case PUBKEY_ALGO_RSA_S:	return 's' ;
+    case PUBKEY_ALGO_ELGAMAL_E: return 'g' ;
+    case PUBKEY_ALGO_ELGAMAL:   return 'G' ;
+    case PUBKEY_ALGO_DSA:	return 'D' ;
+    case PUBKEY_ALGO_ECDH:	return 'e' ;	/* ECC DH (encrypt only) */
+    case PUBKEY_ALGO_ECDSA:	return 'E' ;	/* ECC DSA (sign only)   */
+    case PUBKEY_ALGO_EDDSA:	return 'E' ;	/* ECC EdDSA (sign only) */
+    default: return '?';
+    }
+}
+
+/* Return a string describing the public key algorithm and the
+   keysize.  For elliptic curves the functions prints the name of the
+   curve because the keysize is a property of the curve.  The string
+   is copied to the supplied buffer up a length of BUFSIZE-1.
+   Examples for the output are:
+
+   "rsa2048"  - RSA with 2048 bit
+   "elg1024"  - Elgamal with 1024 bit
+   "ed25519"  - ECC using the curve Ed25519.
+   "E_1.2.3.4"  - ECC using the unsupported curve with OID "1.2.3.4".
+   "E_1.3.6.1.4.1.11591.2.12242973" ECC with a bogus OID.
+   "unknown_N"  - Unknown OpenPGP algorithm N.
+
+   If the option --legacy-list-mode is active, the output use the
+   legacy format:
+
+   "2048R" - RSA with 2048 bit
+   "1024g" - Elgamal with 1024 bit
+   "256E"  - ECDSA using a curve with 256 bit
+
+   The macro PUBKEY_STRING_SIZE may be used to allocate a buffer with
+   a suitable size.*/
+char *
+pubkey_string (PKT_public_key *pk, char *buffer, size_t bufsize)
+{
+  const char *prefix = NULL;
+
+  if (opt.legacy_list_mode)
+    {
+      snprintf (buffer, bufsize, "%4u%c",
+                nbits_from_pk (pk), pubkey_letter (pk->pubkey_algo));
+      return buffer;
+    }
+
+  switch (pk->pubkey_algo)
+    {
+    case PUBKEY_ALGO_RSA:
+    case PUBKEY_ALGO_RSA_E:
+    case PUBKEY_ALGO_RSA_S:	prefix = "rsa"; break;
+    case PUBKEY_ALGO_ELGAMAL_E: prefix = "elg"; break;
+    case PUBKEY_ALGO_DSA:	prefix = "dsa"; break;
+    case PUBKEY_ALGO_ELGAMAL:   prefix = "xxx"; break;
+    case PUBKEY_ALGO_ECDH:
+    case PUBKEY_ALGO_ECDSA:
+    case PUBKEY_ALGO_EDDSA:     prefix = "";    break;
+    }
+
+  if (prefix && *prefix)
+    snprintf (buffer, bufsize, "%s%u", prefix, nbits_from_pk (pk));
+  else if (prefix)
+    {
+      char *curve = openpgp_oid_to_str (pk->pkey[0]);
+      const char *name = openpgp_oid_to_curve (curve, 0);
+
+      if (name)
+        snprintf (buffer, bufsize, "%s", name);
+      else if (curve)
+        snprintf (buffer, bufsize, "E_%s", curve);
+      else
+        snprintf (buffer, bufsize, "E_error");
+      xfree (curve);
+    }
+  else
+    snprintf (buffer, bufsize, "unknown_%u", (unsigned int)pk->pubkey_algo);
+
+  return buffer;
+}
+
+
+/* Hash a public key.  This function is useful for v4 fingerprints and
+   for v3 or v4 key signing. */
+void
+hash_public_key (gcry_md_hd_t md, PKT_public_key *pk)
+{
+  unsigned int n = 6;
+  unsigned int nn[PUBKEY_MAX_NPKEY];
+  byte *pp[PUBKEY_MAX_NPKEY];
+  int i;
+  unsigned int nbits;
+  size_t nbytes;
+  int npkey = pubkey_get_npkey (pk->pubkey_algo);
+
+  /* FIXME: We can avoid the extra malloc by calling only the first
+     mpi_print here which computes the required length and calling the
+     real mpi_print only at the end.  The speed advantage would only be
+     for ECC (opaque MPIs) or if we could implement an mpi_print
+     variant with a callback handler to do the hashing.  */
+  if (npkey==0 && pk->pkey[0]
+      && gcry_mpi_get_flag (pk->pkey[0], GCRYMPI_FLAG_OPAQUE))
+    {
+      pp[0] = gcry_mpi_get_opaque (pk->pkey[0], &nbits);
+      nn[0] = (nbits+7)/8;
+      n+=nn[0];
+    }
+  else
+    {
+      for (i=0; i < npkey; i++ )
+        {
+          if (!pk->pkey[i])
+            {
+              /* This case may only happen if the parsing of the MPI
+                 failed but the key was anyway created.  May happen
+                 during "gpg KEYFILE".  */
+              pp[i] = NULL;
+              nn[i] = 0;
+            }
+          else if (gcry_mpi_get_flag (pk->pkey[i], GCRYMPI_FLAG_OPAQUE))
+            {
+              const void *p;
+
+              p = gcry_mpi_get_opaque (pk->pkey[i], &nbits);
+              pp[i] = xmalloc ((nbits+7)/8);
+              if (p)
+                memcpy (pp[i], p, (nbits+7)/8);
+              else
+                pp[i] = NULL;
+              nn[i] = (nbits+7)/8;
+              n += nn[i];
+            }
+          else
+            {
+              if (gcry_mpi_print (GCRYMPI_FMT_PGP, NULL, 0,
+                                  &nbytes, pk->pkey[i]))
+                BUG ();
+              pp[i] = xmalloc (nbytes);
+              if (gcry_mpi_print (GCRYMPI_FMT_PGP, pp[i], nbytes,
+                                  &nbytes, pk->pkey[i]))
+                BUG ();
+              nn[i] = nbytes;
+              n += nn[i];
+            }
+        }
+    }
+
+  gcry_md_putc ( md, 0x99 );     /* ctb */
+  /* What does it mean if n is greater than 0xFFFF ? */
+  gcry_md_putc ( md, n >> 8 );   /* 2 byte length header */
+  gcry_md_putc ( md, n );
+  gcry_md_putc ( md, pk->version );
+
+  gcry_md_putc ( md, pk->timestamp >> 24 );
+  gcry_md_putc ( md, pk->timestamp >> 16 );
+  gcry_md_putc ( md, pk->timestamp >>  8 );
+  gcry_md_putc ( md, pk->timestamp       );
+
+  gcry_md_putc ( md, pk->pubkey_algo );
+
+  if(npkey==0 && pk->pkey[0]
+     && gcry_mpi_get_flag (pk->pkey[0], GCRYMPI_FLAG_OPAQUE))
+    {
+      if (pp[0])
+        gcry_md_write (md, pp[0], nn[0]);
+    }
+  else
+    {
+      for(i=0; i < npkey; i++ )
+        {
+          if (pp[i])
+            gcry_md_write ( md, pp[i], nn[i] );
+          xfree(pp[i]);
+        }
+    }
+}
+
+
+static gcry_md_hd_t
+do_fingerprint_md( PKT_public_key *pk )
+{
+  gcry_md_hd_t md;
+
+  if (gcry_md_open (&md, DIGEST_ALGO_SHA1, 0))
+    BUG ();
+  hash_public_key(md,pk);
+  gcry_md_final( md );
+
+  return md;
+}
+
+
+/* fixme: Check whether we can replace this function or if not
+   describe why we need it.  */
+u32
+v3_keyid (gcry_mpi_t a, u32 *ki)
+{
+  byte *buffer, *p;
+  size_t nbytes;
+
+  if (gcry_mpi_print (GCRYMPI_FMT_USG, NULL, 0, &nbytes, a ))
+    BUG ();
+  /* fixme: allocate it on the stack */
+  buffer = xmalloc (nbytes);
+  if (gcry_mpi_print( GCRYMPI_FMT_USG, buffer, nbytes, NULL, a ))
+    BUG ();
+  if (nbytes < 8) /* oops */
+    ki[0] = ki[1] = 0;
+  else
+    {
+      p = buffer + nbytes - 8;
+      ki[0] = buf32_to_u32 (p);
+      p += 4;
+      ki[1] = buf32_to_u32 (p);
+    }
+  xfree (buffer);
+  return ki[1];
+}
+
+
+/* Return PK's keyid.  The memory is owned by PK.  */
+u32 *
+pk_keyid (PKT_public_key *pk)
+{
+  keyid_from_pk (pk, NULL);
+
+  /* Uncomment this for help tracking down bugs related to keyid or
+     main_keyid not being set correctly.  */
+#if 0
+  if (! (pk->main_keyid[0] || pk->main_keyid[1]))
+    log_bug ("pk->main_keyid not set!\n");
+  if (keyid_cmp (pk->keyid, pk->main_keyid) == 0
+      && ! pk->flags.primary)
+    log_bug ("keyid and main_keyid are the same, but primary flag not set!\n");
+  if (keyid_cmp (pk->keyid, pk->main_keyid) != 0
+      && pk->flags.primary)
+    log_bug ("keyid and main_keyid are different, but primary flag set!\n");
+#endif
+
+  return pk->keyid;
+}
+
+/* Return the keyid of the primary key associated with PK.  The memory
+   is owned by PK.  */
+u32 *
+pk_main_keyid (PKT_public_key *pk)
+{
+  /* Uncomment this for help tracking down bugs related to keyid or
+     main_keyid not being set correctly.  */
+#if 0
+  if (! (pk->main_keyid[0] || pk->main_keyid[1]))
+    log_bug ("pk->main_keyid not set!\n");
+#endif
+
+  return pk->main_keyid;
+}
+
+/* Copy the keyid in SRC to DEST and return DEST.  */
+u32 *
+keyid_copy (u32 *dest, const u32 *src)
+{
+  dest[0] = src[0];
+  dest[1] = src[1];
+  return dest;
+}
+
+char *
+format_keyid (u32 *keyid, int format, char *buffer, int len)
+{
+  char tmp[KEYID_STR_SIZE];
+  if (! buffer)
+    {
+      buffer = tmp;
+      len = sizeof (tmp);
+    }
+
+  if (format == KF_DEFAULT)
+    format = opt.keyid_format;
+  if (format == KF_DEFAULT)
+    format = KF_NONE;
+
+  switch (format)
+    {
+    case KF_NONE:
+      if (len)
+        *buffer = 0;
+      break;
+
+    case KF_SHORT:
+      snprintf (buffer, len, "%08lX", (ulong)keyid[1]);
+      break;
+
+    case KF_LONG:
+      snprintf (buffer, len, "%08lX%08lX", (ulong)keyid[0], (ulong)keyid[1]);
+      break;
+
+    case KF_0xSHORT:
+      snprintf (buffer, len, "0x%08lX", (ulong)keyid[1]);
+      break;
+
+    case KF_0xLONG:
+      snprintf (buffer, len, "0x%08lX%08lX", (ulong)keyid[0],(ulong)keyid[1]);
+      break;
+
+    default:
+      BUG();
+    }
+
+  if (buffer == tmp)
+    return xstrdup (buffer);
+  return buffer;
+}
+
+size_t
+keystrlen(void)
+{
+  int format = opt.keyid_format;
+  if (format == KF_DEFAULT)
+    format = KF_NONE;
+
+  switch(format)
+    {
+    case KF_NONE:
+      return 0;
+
+    case KF_SHORT:
+      return 8;
+
+    case KF_LONG:
+      return 16;
+
+    case KF_0xSHORT:
+      return 10;
+
+    case KF_0xLONG:
+      return 18;
+
+    default:
+      BUG();
+    }
+}
+
+
+const char *
+keystr (u32 *keyid)
+{
+  static char keyid_str[KEYID_STR_SIZE];
+  int format = opt.keyid_format;
+
+  if (format == KF_DEFAULT)
+    format = KF_NONE;
+  if (format == KF_NONE)
+    format = KF_LONG;
+
+  return format_keyid (keyid, format, keyid_str, sizeof (keyid_str));
+}
+
+/* This function returns the key id of the main and possible the
+ * subkey as one string.  It is used by error messages.  */
+const char *
+keystr_with_sub (u32 *main_kid, u32 *sub_kid)
+{
+  static char buffer[KEYID_STR_SIZE+1+KEYID_STR_SIZE];
+  char *p;
+  int format = opt.keyid_format;
+
+  if (format == KF_NONE)
+    format = KF_LONG;
+
+  format_keyid (main_kid, format, buffer, KEYID_STR_SIZE);
+  if (sub_kid)
+    {
+      p = buffer + strlen (buffer);
+      *p++ = '/';
+      format_keyid (sub_kid, format, p, KEYID_STR_SIZE);
+    }
+  return buffer;
+}
+
+
+const char *
+keystr_from_pk(PKT_public_key *pk)
+{
+  keyid_from_pk(pk,NULL);
+
+  return keystr(pk->keyid);
+}
+
+
+const char *
+keystr_from_pk_with_sub (PKT_public_key *main_pk, PKT_public_key *sub_pk)
+{
+  keyid_from_pk (main_pk, NULL);
+  if (sub_pk)
+    keyid_from_pk (sub_pk, NULL);
+
+  return keystr_with_sub (main_pk->keyid, sub_pk? sub_pk->keyid:NULL);
+}
+
+
+/* Return PK's key id as a string using the default format.  PK owns
+   the storage.  */
+const char *
+pk_keyid_str (PKT_public_key *pk)
+{
+  return keystr (pk_keyid (pk));
+}
+
+
+const char *
+keystr_from_desc(KEYDB_SEARCH_DESC *desc)
+{
+  switch(desc->mode)
+    {
+    case KEYDB_SEARCH_MODE_LONG_KID:
+    case KEYDB_SEARCH_MODE_SHORT_KID:
+      return keystr(desc->u.kid);
+
+    case KEYDB_SEARCH_MODE_FPR20:
+      {
+	u32 keyid[2];
+
+	keyid[0] = buf32_to_u32 (desc->u.fpr+12);
+	keyid[1] = buf32_to_u32 (desc->u.fpr+16);
+	return keystr(keyid);
+      }
+
+    case KEYDB_SEARCH_MODE_FPR16:
+      return "?v3 fpr?";
+
+    default:
+      BUG();
+    }
+}
+
+
+/*
+ * Get the keyid from the public key and put it into keyid
+ * if this is not NULL. Return the 32 low bits of the keyid.
+ */
+u32
+keyid_from_pk (PKT_public_key *pk, u32 *keyid)
+{
+  u32 lowbits;
+  u32 dummy_keyid[2];
+
+  if (!keyid)
+    keyid = dummy_keyid;
+
+  if( pk->keyid[0] || pk->keyid[1] )
+    {
+      keyid[0] = pk->keyid[0];
+      keyid[1] = pk->keyid[1];
+      lowbits = keyid[1];
+    }
+  else
+    {
+      const byte *dp;
+      gcry_md_hd_t md;
+
+      md = do_fingerprint_md(pk);
+      if(md)
+	{
+	  dp = gcry_md_read ( md, 0 );
+	  keyid[0] = buf32_to_u32 (dp+12);
+	  keyid[1] = buf32_to_u32 (dp+16);
+	  lowbits = keyid[1];
+	  gcry_md_close (md);
+	  pk->keyid[0] = keyid[0];
+	  pk->keyid[1] = keyid[1];
+	}
+      else
+	pk->keyid[0]=pk->keyid[1]=keyid[0]=keyid[1]=lowbits=0xFFFFFFFF;
+    }
+
+  return lowbits;
+}
+
+
+/*
+ * Get the keyid from the fingerprint.	This function is simple for most
+ * keys, but has to do a keylookup for old stayle keys.
+ */
+u32
+keyid_from_fingerprint (ctrl_t ctrl, const byte *fprint,
+                        size_t fprint_len, u32 *keyid)
+{
+  u32 dummy_keyid[2];
+
+  if( !keyid )
+    keyid = dummy_keyid;
+
+  if (fprint_len != 20)
+    {
+      /* This is special as we have to lookup the key first.  */
+      PKT_public_key pk;
+      int rc;
+
+      memset (&pk, 0, sizeof pk);
+      rc = get_pubkey_byfprint (ctrl, &pk, NULL, fprint, fprint_len);
+      if( rc )
+        {
+          log_error("Oops: keyid_from_fingerprint: no pubkey\n");
+          keyid[0] = 0;
+          keyid[1] = 0;
+        }
+      else
+        keyid_from_pk (&pk, keyid);
+    }
+  else
+    {
+      const byte *dp = fprint;
+      keyid[0] = buf32_to_u32 (dp+12);
+      keyid[1] = buf32_to_u32 (dp+16);
+    }
+
+  return keyid[1];
+}
+
+
+u32
+keyid_from_sig (PKT_signature *sig, u32 *keyid)
+{
+  if( keyid )
+    {
+      keyid[0] = sig->keyid[0];
+      keyid[1] = sig->keyid[1];
+    }
+  return sig->keyid[1];
+}
+
+
+byte *
+namehash_from_uid (PKT_user_id *uid)
+{
+  if (!uid->namehash)
+    {
+      uid->namehash = xmalloc (20);
+
+      if (uid->attrib_data)
+	rmd160_hash_buffer (uid->namehash, uid->attrib_data, uid->attrib_len);
+      else
+	rmd160_hash_buffer (uid->namehash, uid->name, uid->len);
+    }
+
+  return uid->namehash;
+}
+
+
+/*
+ * Return the number of bits used in PK.
+ */
+unsigned int
+nbits_from_pk (PKT_public_key *pk)
+{
+    return pubkey_nbits (pk->pubkey_algo, pk->pkey);
+}
+
+
+/* Convert an UTC TIMESTAMP into an UTC yyyy-mm-dd string.  Return
+ * that string.  The caller should pass a buffer with at least a size
+ * of MK_DATESTR_SIZE.  */
+char *
+mk_datestr (char *buffer, size_t bufsize, u32 timestamp)
+{
+  time_t atime = timestamp;
+  struct tm *tp;
+
+  if (IS_INVALID_TIME_T (atime))
+    strcpy (buffer, "????" "-??" "-??"); /* Mark this as invalid. */
+  else
+    {
+      tp = gmtime (&atime);
+      snprintf (buffer, bufsize, "%04d-%02d-%02d",
+                1900+tp->tm_year, tp->tm_mon+1, tp->tm_mday );
+    }
+  return buffer;
+}
+
+
+/*
+ * return a string with the creation date of the pk
+ * Note: this is alloced in a static buffer.
+ *    Format is: yyyy-mm-dd
+ */
+const char *
+datestr_from_pk (PKT_public_key *pk)
+{
+  static char buffer[MK_DATESTR_SIZE];
+
+  return mk_datestr (buffer, sizeof buffer, pk->timestamp);
+}
+
+
+const char *
+datestr_from_sig (PKT_signature *sig )
+{
+  static char buffer[MK_DATESTR_SIZE];
+
+  return mk_datestr (buffer, sizeof buffer, sig->timestamp);
+}
+
+
+const char *
+expirestr_from_pk (PKT_public_key *pk)
+{
+  static char buffer[MK_DATESTR_SIZE];
+
+  if (!pk->expiredate)
+    return _("never     ");
+  return mk_datestr (buffer, sizeof buffer, pk->expiredate);
+}
+
+
+const char *
+expirestr_from_sig (PKT_signature *sig)
+{
+  static char buffer[MK_DATESTR_SIZE];
+
+  if (!sig->expiredate)
+    return _("never     ");
+  return mk_datestr (buffer, sizeof buffer, sig->expiredate);
+}
+
+
+const char *
+revokestr_from_pk( PKT_public_key *pk )
+{
+  static char buffer[MK_DATESTR_SIZE];
+
+  if(!pk->revoked.date)
+    return _("never     ");
+  return mk_datestr (buffer, sizeof buffer, pk->revoked.date);
+}
+
+
+const char *
+usagestr_from_pk (PKT_public_key *pk, int fill)
+{
+  static char buffer[10];
+  int i = 0;
+  unsigned int use = pk->pubkey_usage;
+
+  if ( use & PUBKEY_USAGE_SIG )
+    buffer[i++] = 'S';
+
+  if ( use & PUBKEY_USAGE_CERT )
+    buffer[i++] = 'C';
+
+  if ( use & PUBKEY_USAGE_ENC )
+    buffer[i++] = 'E';
+
+  if ( (use & PUBKEY_USAGE_AUTH) )
+    buffer[i++] = 'A';
+
+  while (fill && i < 4)
+    buffer[i++] = ' ';
+
+  buffer[i] = 0;
+  return buffer;
+}
+
+
+const char *
+colon_strtime (u32 t)
+{
+  static char buf[20];
+
+  if (!t)
+    return "";
+  snprintf (buf, sizeof buf, "%lu", (ulong)t);
+  return buf;
+}
+
+const char *
+colon_datestr_from_pk (PKT_public_key *pk)
+{
+  static char buf[20];
+
+  snprintf (buf, sizeof buf, "%lu", (ulong)pk->timestamp);
+  return buf;
+}
+
+
+const char *
+colon_datestr_from_sig (PKT_signature *sig)
+{
+  static char buf[20];
+
+  snprintf (buf, sizeof buf, "%lu", (ulong)sig->timestamp);
+  return buf;
+}
+
+const char *
+colon_expirestr_from_sig (PKT_signature *sig)
+{
+  static char buf[20];
+
+  if (!sig->expiredate)
+    return "";
+
+  snprintf (buf, sizeof buf,"%lu", (ulong)sig->expiredate);
+  return buf;
+}
+
+
+/*
+ * Return a byte array with the fingerprint for the given PK/SK
+ * The length of the array is returned in ret_len. Caller must free
+ * the array or provide an array of length MAX_FINGERPRINT_LEN.
+ */
+byte *
+fingerprint_from_pk (PKT_public_key *pk, byte *array, size_t *ret_len)
+{
+  const byte *dp;
+  size_t len;
+  gcry_md_hd_t md;
+
+  md = do_fingerprint_md(pk);
+  dp = gcry_md_read( md, 0 );
+  len = gcry_md_get_algo_dlen (gcry_md_get_algo (md));
+  log_assert( len <= MAX_FINGERPRINT_LEN );
+  if (!array)
+    array = xmalloc ( len );
+  memcpy (array, dp, len );
+  pk->keyid[0] = buf32_to_u32 (dp+12);
+  pk->keyid[1] = buf32_to_u32 (dp+16);
+  gcry_md_close( md);
+
+  if (ret_len)
+    *ret_len = len;
+  return array;
+}
+
+
+/* Return an allocated buffer with the fingerprint of PK formatted as
+ * a plain hexstring.  If BUFFER is NULL the result is a malloc'd
+ * string.  If BUFFER is not NULL the result will be copied into this
+ * buffer.  In the latter case BUFLEN describes the length of the
+ * buffer; if this is too short the function terminates the process.
+ * Returns a malloc'ed string or BUFFER.  A suitable length for BUFFER
+ * is (2*MAX_FINGERPRINT_LEN + 1). */
+char *
+hexfingerprint (PKT_public_key *pk, char *buffer, size_t buflen)
+{
+  unsigned char fpr[MAX_FINGERPRINT_LEN];
+  size_t len;
+
+  fingerprint_from_pk (pk, fpr, &len);
+  if (!buffer)
+    {
+      buffer = xtrymalloc (2 * len + 1);
+      if (!buffer)
+        return NULL;
+    }
+  else if (buflen < 2*len+1)
+    log_fatal ("%s: buffer too short (%zu)\n", __func__, buflen);
+  bin2hex (fpr, len, buffer);
+  return buffer;
+}
+
+
+/* Pretty print a hex fingerprint.  If BUFFER is NULL the result is a
+   malloc'd string.  If BUFFER is not NULL the result will be copied
+   into this buffer.  In the latter case BUFLEN describes the length
+   of the buffer; if this is too short the function terminates the
+   process.  Returns a malloc'ed string or BUFFER.  A suitable length
+   for BUFFER is (MAX_FORMATTED_FINGERPRINT_LEN + 1).  */
+char *
+format_hexfingerprint (const char *fingerprint, char *buffer, size_t buflen)
+{
+  int hexlen = strlen (fingerprint);
+  int space;
+  int i, j;
+
+  if (hexlen == 40)  /* v4 fingerprint */
+    {
+      space = (/* The characters and the NUL.  */
+	       40 + 1
+	       /* After every fourth character, we add a space (except
+		  the last).  */
+	       + 40 / 4 - 1
+	       /* Half way through we add a second space.  */
+	       + 1);
+    }
+  else  /* Other fingerprint versions - print as is.  */
+    {
+      space = hexlen + 1;
+    }
+
+  if (!buffer)
+    buffer = xmalloc (space);
+  else if (buflen < space)
+    log_fatal ("%s: buffer too short (%zu)\n", __func__, buflen);
+
+  if (hexlen == 40)  /* v4 fingerprint */
+    {
+      for (i = 0, j = 0; i < 40; i ++)
+        {
+          if (i && i % 4 == 0)
+            buffer[j ++] = ' ';
+          if (i == 40 / 2)
+            buffer[j ++] = ' ';
+
+          buffer[j ++] = fingerprint[i];
+        }
+      buffer[j ++] = 0;
+      log_assert (j == space);
+    }
+  else
+    {
+      strcpy (buffer, fingerprint);
+    }
+
+  return buffer;
+}
+
+
+
+/* Return the so called KEYGRIP which is the SHA-1 hash of the public
+   key parameters expressed as an canoncial encoded S-Exp.  ARRAY must
+   be 20 bytes long.  Returns 0 on success or an error code.  */
+gpg_error_t
+keygrip_from_pk (PKT_public_key *pk, unsigned char *array)
+{
+  gpg_error_t err;
+  gcry_sexp_t s_pkey;
+
+  if (DBG_PACKET)
+    log_debug ("get_keygrip for public key\n");
+
+  switch (pk->pubkey_algo)
+    {
+    case GCRY_PK_DSA:
+      err = gcry_sexp_build (&s_pkey, NULL,
+                             "(public-key(dsa(p%m)(q%m)(g%m)(y%m)))",
+                             pk->pkey[0], pk->pkey[1],
+                             pk->pkey[2], pk->pkey[3]);
+      break;
+
+    case GCRY_PK_ELG:
+    case GCRY_PK_ELG_E:
+      err = gcry_sexp_build (&s_pkey, NULL,
+                             "(public-key(elg(p%m)(g%m)(y%m)))",
+                             pk->pkey[0], pk->pkey[1], pk->pkey[2]);
+      break;
+
+    case GCRY_PK_RSA:
+    case GCRY_PK_RSA_S:
+    case GCRY_PK_RSA_E:
+      err = gcry_sexp_build (&s_pkey, NULL,
+                             "(public-key(rsa(n%m)(e%m)))",
+                             pk->pkey[0], pk->pkey[1]);
+      break;
+
+    case PUBKEY_ALGO_EDDSA:
+    case PUBKEY_ALGO_ECDSA:
+    case PUBKEY_ALGO_ECDH:
+      {
+        char *curve = openpgp_oid_to_str (pk->pkey[0]);
+        if (!curve)
+          err = gpg_error_from_syserror ();
+        else
+          {
+            err = gcry_sexp_build (&s_pkey, NULL,
+                                   pk->pubkey_algo == PUBKEY_ALGO_EDDSA?
+                                   "(public-key(ecc(curve%s)(flags eddsa)(q%m)))":
+                                   (pk->pubkey_algo == PUBKEY_ALGO_ECDH
+                                    && openpgp_oid_is_cv25519 (pk->pkey[0]))?
+                                   "(public-key(ecc(curve%s)(flags djb-tweak)(q%m)))":
+                                   "(public-key(ecc(curve%s)(q%m)))",
+                                   curve, pk->pkey[1]);
+            xfree (curve);
+          }
+      }
+      break;
+
+    default:
+      err = gpg_error (GPG_ERR_PUBKEY_ALGO);
+      break;
+    }
+
+  if (err)
+    return err;
+
+  if (!gcry_pk_get_keygrip (s_pkey, array))
+    {
+      char *hexfpr;
+
+      hexfpr = hexfingerprint (pk, NULL, 0);
+      log_info ("error computing keygrip (fpr=%s)\n", hexfpr);
+      xfree (hexfpr);
+
+      memset (array, 0, 20);
+      err = gpg_error (GPG_ERR_GENERAL);
+    }
+  else
+    {
+      if (DBG_PACKET)
+        log_printhex (array, 20, "keygrip=");
+      /* FIXME: Save the keygrip in PK.  */
+    }
+  gcry_sexp_release (s_pkey);
+
+  return err;
+}
+
+
+/* Store an allocated buffer with the keygrip of PK encoded as a
+   hexstring at r_GRIP.  Returns 0 on success.  */
+gpg_error_t
+hexkeygrip_from_pk (PKT_public_key *pk, char **r_grip)
+{
+  gpg_error_t err;
+  unsigned char grip[20];
+
+  *r_grip = NULL;
+  err = keygrip_from_pk (pk, grip);
+  if (!err)
+    {
+      char * buf = xtrymalloc (20*2+1);
+      if (!buf)
+        err = gpg_error_from_syserror ();
+      else
+        {
+          bin2hex (grip, 20, buf);
+          *r_grip = buf;
+        }
+    }
+  return err;
+}