Add support to talking to LDAP key servers.

* g10/call-dirmngr.c (record_output): New function.
(ks_put_inq_cb): Use it here to generate a --with-colons like output
instead of a custom format.
* dirmngr/ks-action.c: Include "ldap-parse-uri.h".
(ks_action_help): If the provided URI is an LDAP URI, then use
ldap_parse_uri to parse.  Call ks_ldap_help.
(ks_action_search): If passed an LDAP URI, then call ks_ldap_search.
(ks_action_get): Likewise.
(ks_action_put): Likewise.  Also, change data from a 'const void *' to
a 'void *' and add info and infolen parameters.  Add note that
function may modify DATA.
* dirmngr/ks-action.h (ks_action_put): Update declaration accordingly.
* dirmngr/server.c: Include "ldap-parse-uri.h".
(cmd_keyserver): If ITEM->URI is an LDAP URI, parse it using
ldap_parse_uri.
(hlp_ks_put): Improve documentation.
(cmd_ks_put): Also pass info and infolen to ks_action_put.  Improve
documentation.
* dirmngr/ks-engine.h (ks_ldap_help): New declaration.
(ks_ldap_search): Likewise.
(ks_ldap_get): Likewise.
(ks_ldap_put): Likewise.
* dirmngr/ks-engine-ldap.c: New file.
* dirmngr/Makefile.am (dirmngr_SOURCES): Add ks-engine-ldap.c,
ldap-parse-uri.c and ldap-parse-uri.h.
(dirmngr_LDADD) [USE_LDAP]: Add $(ldaplibs).

--
Signed-off-by: Neal H. Walfield <[email protected]>

1 files changed, 2055 insertions, 0 deletions

diff --git a/dirmngr/ks-engine-ldap.c b/dirmngr/ks-engine-ldap.c
new file mode 100644
index 000000000..68a1bb73e
--- /dev/null
+++ b/dirmngr/ks-engine-ldap.c
@@ -0,0 +1,2055 @@
+/* ks-engine-ldap.c - talk to a LDAP keyserver
+ * Copyright (C) 2001, 2002, 2004, 2005, 2006
+ *               2007  Free Software Foundation, Inc.
+ * Copyright (C) 2015  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 <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#ifdef HAVE_GETOPT_H
+# include <getopt.h>
+#endif
+#include <stdlib.h>
+#include <errno.h>
+#include <assert.h>
+
+#ifdef _WIN32
+# include <winsock2.h>
+# include <winldap.h>
+#else
+# ifdef NEED_LBER_H
+#  include <lber.h>
+# endif
+/* For OpenLDAP, to enable the API that we're using. */
+# define LDAP_DEPRECATED 1
+# include <ldap.h>
+#endif
+
+#include "dirmngr.h"
+#include "misc.h"
+#include "userids.h"
+#include "ks-engine.h"
+#include "ldap-parse-uri.h"
+
+#ifdef __riscos__
+# include "util.h"
+#endif
+
+#ifndef HAVE_TIMEGM
+time_t timegm(struct tm *tm);
+#endif
+
+/* Convert an LDAP error to a GPG error.  */
+static int
+ldap_err_to_gpg_err (int code)
+{
+  gpg_err_code_t ec;
+
+  switch (code)
+    {
+#ifdef LDAP_X_CONNECTING
+    case LDAP_X_CONNECTING: ec = GPG_ERR_LDAP_X_CONNECTING; break;
+#endif
+
+    case LDAP_REFERRAL_LIMIT_EXCEEDED: ec = GPG_ERR_LDAP_REFERRAL_LIMIT; break;
+    case LDAP_CLIENT_LOOP: ec = GPG_ERR_LDAP_CLIENT_LOOP; break;
+    case LDAP_NO_RESULTS_RETURNED: ec = GPG_ERR_LDAP_NO_RESULTS; break;
+    case LDAP_CONTROL_NOT_FOUND: ec = GPG_ERR_LDAP_CONTROL_NOT_FOUND; break;
+    case LDAP_NOT_SUPPORTED: ec = GPG_ERR_LDAP_NOT_SUPPORTED; break;
+    case LDAP_CONNECT_ERROR: ec = GPG_ERR_LDAP_CONNECT; break;
+    case LDAP_NO_MEMORY: ec = GPG_ERR_LDAP_NO_MEMORY; break;
+    case LDAP_PARAM_ERROR: ec = GPG_ERR_LDAP_PARAM; break;
+    case LDAP_USER_CANCELLED: ec = GPG_ERR_LDAP_USER_CANCELLED; break;
+    case LDAP_FILTER_ERROR: ec = GPG_ERR_LDAP_FILTER; break;
+    case LDAP_AUTH_UNKNOWN: ec = GPG_ERR_LDAP_AUTH_UNKNOWN; break;
+    case LDAP_TIMEOUT: ec = GPG_ERR_LDAP_TIMEOUT; break;
+    case LDAP_DECODING_ERROR: ec = GPG_ERR_LDAP_DECODING; break;
+    case LDAP_ENCODING_ERROR: ec = GPG_ERR_LDAP_ENCODING; break;
+    case LDAP_LOCAL_ERROR: ec = GPG_ERR_LDAP_LOCAL; break;
+    case LDAP_SERVER_DOWN: ec = GPG_ERR_LDAP_SERVER_DOWN; break;
+
+    case LDAP_SUCCESS: ec = GPG_ERR_LDAP_SUCCESS; break;
+
+    case LDAP_OPERATIONS_ERROR: ec = GPG_ERR_LDAP_OPERATIONS; break;
+    case LDAP_PROTOCOL_ERROR: ec = GPG_ERR_LDAP_PROTOCOL; break;
+    case LDAP_TIMELIMIT_EXCEEDED: ec = GPG_ERR_LDAP_TIMELIMIT; break;
+    case LDAP_SIZELIMIT_EXCEEDED: ec = GPG_ERR_LDAP_SIZELIMIT; break;
+    case LDAP_COMPARE_FALSE: ec = GPG_ERR_LDAP_COMPARE_FALSE; break;
+    case LDAP_COMPARE_TRUE: ec = GPG_ERR_LDAP_COMPARE_TRUE; break;
+    case LDAP_AUTH_METHOD_NOT_SUPPORTED: ec=GPG_ERR_LDAP_UNSUPPORTED_AUTH;break;
+    case LDAP_STRONG_AUTH_REQUIRED: ec = GPG_ERR_LDAP_STRONG_AUTH_RQRD; break;
+    case LDAP_PARTIAL_RESULTS: ec = GPG_ERR_LDAP_PARTIAL_RESULTS; break;
+    case LDAP_REFERRAL: ec = GPG_ERR_LDAP_REFERRAL; break;
+
+#ifdef LDAP_ADMINLIMIT_EXCEEDED
+    case LDAP_ADMINLIMIT_EXCEEDED: ec = GPG_ERR_LDAP_ADMINLIMIT; break;
+#endif
+
+#ifdef LDAP_UNAVAILABLE_CRITICAL_EXTENSION
+    case LDAP_UNAVAILABLE_CRITICAL_EXTENSION:
+                               ec = GPG_ERR_LDAP_UNAVAIL_CRIT_EXTN; break;
+#endif
+
+    case LDAP_CONFIDENTIALITY_REQUIRED: ec = GPG_ERR_LDAP_CONFIDENT_RQRD; break;
+    case LDAP_SASL_BIND_IN_PROGRESS: ec = GPG_ERR_LDAP_SASL_BIND_INPROG; break;
+    case LDAP_NO_SUCH_ATTRIBUTE: ec = GPG_ERR_LDAP_NO_SUCH_ATTRIBUTE; break;
+    case LDAP_UNDEFINED_TYPE: ec = GPG_ERR_LDAP_UNDEFINED_TYPE; break;
+    case LDAP_INAPPROPRIATE_MATCHING: ec = GPG_ERR_LDAP_BAD_MATCHING; break;
+    case LDAP_CONSTRAINT_VIOLATION: ec = GPG_ERR_LDAP_CONST_VIOLATION; break;
+
+#ifdef LDAP_TYPE_OR_VALUE_EXISTS
+    case LDAP_TYPE_OR_VALUE_EXISTS: ec = GPG_ERR_LDAP_TYPE_VALUE_EXISTS; break;
+#endif
+
+    case LDAP_INVALID_SYNTAX: ec = GPG_ERR_LDAP_INV_SYNTAX; break;
+    case LDAP_NO_SUCH_OBJECT: ec = GPG_ERR_LDAP_NO_SUCH_OBJ; break;
+    case LDAP_ALIAS_PROBLEM: ec = GPG_ERR_LDAP_ALIAS_PROBLEM; break;
+    case LDAP_INVALID_DN_SYNTAX: ec = GPG_ERR_LDAP_INV_DN_SYNTAX; break;
+    case LDAP_IS_LEAF: ec = GPG_ERR_LDAP_IS_LEAF; break;
+    case LDAP_ALIAS_DEREF_PROBLEM: ec = GPG_ERR_LDAP_ALIAS_DEREF; break;
+
+#ifdef LDAP_X_PROXY_AUTHZ_FAILURE
+    case LDAP_X_PROXY_AUTHZ_FAILURE: ec = GPG_ERR_LDAP_X_PROXY_AUTH_FAIL; break;
+#endif
+
+    case LDAP_INAPPROPRIATE_AUTH: ec = GPG_ERR_LDAP_BAD_AUTH; break;
+    case LDAP_INVALID_CREDENTIALS: ec = GPG_ERR_LDAP_INV_CREDENTIALS; break;
+
+#ifdef LDAP_INSUFFICIENT_ACCESS
+    case LDAP_INSUFFICIENT_ACCESS: ec = GPG_ERR_LDAP_INSUFFICIENT_ACC; break;
+#endif
+
+    case LDAP_BUSY: ec = GPG_ERR_LDAP_BUSY; break;
+    case LDAP_UNAVAILABLE: ec = GPG_ERR_LDAP_UNAVAILABLE; break;
+    case LDAP_UNWILLING_TO_PERFORM: ec = GPG_ERR_LDAP_UNWILL_TO_PERFORM; break;
+    case LDAP_LOOP_DETECT: ec = GPG_ERR_LDAP_LOOP_DETECT; break;
+    case LDAP_NAMING_VIOLATION: ec = GPG_ERR_LDAP_NAMING_VIOLATION; break;
+    case LDAP_OBJECT_CLASS_VIOLATION: ec = GPG_ERR_LDAP_OBJ_CLS_VIOLATION; break;
+    case LDAP_NOT_ALLOWED_ON_NONLEAF: ec=GPG_ERR_LDAP_NOT_ALLOW_NONLEAF;break;
+    case LDAP_NOT_ALLOWED_ON_RDN: ec = GPG_ERR_LDAP_NOT_ALLOW_ON_RDN; break;
+    case LDAP_ALREADY_EXISTS: ec = GPG_ERR_LDAP_ALREADY_EXISTS; break;
+    case LDAP_NO_OBJECT_CLASS_MODS: ec = GPG_ERR_LDAP_NO_OBJ_CLASS_MODS; break;
+    case LDAP_RESULTS_TOO_LARGE: ec = GPG_ERR_LDAP_RESULTS_TOO_LARGE; break;
+    case LDAP_AFFECTS_MULTIPLE_DSAS: ec = GPG_ERR_LDAP_AFFECTS_MULT_DSAS; break;
+
+#ifdef LDAP_VLV_ERROR
+    case LDAP_VLV_ERROR: ec = GPG_ERR_LDAP_VLV; break;
+#endif
+
+    case LDAP_OTHER: ec = GPG_ERR_LDAP_OTHER; break;
+
+#ifdef LDAP_CUP_RESOURCES_EXHAUSTED
+    case LDAP_CUP_RESOURCES_EXHAUSTED: ec=GPG_ERR_LDAP_CUP_RESOURCE_LIMIT;break;
+    case LDAP_CUP_SECURITY_VIOLATION: ec=GPG_ERR_LDAP_CUP_SEC_VIOLATION; break;
+    case LDAP_CUP_INVALID_DATA: ec = GPG_ERR_LDAP_CUP_INV_DATA; break;
+    case LDAP_CUP_UNSUPPORTED_SCHEME: ec = GPG_ERR_LDAP_CUP_UNSUP_SCHEME; break;
+    case LDAP_CUP_RELOAD_REQUIRED: ec = GPG_ERR_LDAP_CUP_RELOAD; break;
+#endif
+
+#ifdef LDAP_CANCELLED
+    case LDAP_CANCELLED: ec = GPG_ERR_LDAP_CANCELLED; break;
+#endif
+
+#ifdef LDAP_NO_SUCH_OPERATION
+    case LDAP_NO_SUCH_OPERATION: ec = GPG_ERR_LDAP_NO_SUCH_OPERATION; break;
+#endif
+
+#ifdef LDAP_TOO_LATE
+    case LDAP_TOO_LATE: ec = GPG_ERR_LDAP_TOO_LATE; break;
+#endif
+
+#ifdef LDAP_CANNOT_CANCEL
+    case LDAP_CANNOT_CANCEL: ec = GPG_ERR_LDAP_CANNOT_CANCEL; break;
+#endif
+
+#ifdef LDAP_ASSERTION_FAILED
+    case LDAP_ASSERTION_FAILED: ec = GPG_ERR_LDAP_ASSERTION_FAILED; break;
+#endif
+
+#ifdef LDAP_PROXIED_AUTHORIZATION_DENIED
+    case LDAP_PROXIED_AUTHORIZATION_DENIED:
+                                      ec = GPG_ERR_LDAP_PROX_AUTH_DENIED; break;
+#endif
+
+    default:
+#if defined(LDAP_E_ERROR) && defined(LDAP_X_ERROR)
+      if (LDAP_E_ERROR (code))
+        ec = GPG_ERR_LDAP_E_GENERAL;
+      else if (LDAP_X_ERROR (code))
+        ec = GPG_ERR_LDAP_X_GENERAL;
+      else
+#endif
+        ec = GPG_ERR_LDAP_GENERAL;
+      break;
+    }
+
+  return ec;
+}
+
+/* Retrieve an LDAP error and return it's GPG equivalent.  */
+static int
+ldap_to_gpg_err (LDAP *ld)
+{
+#if defined(HAVE_LDAP_GET_OPTION) && defined(LDAP_OPT_ERROR_NUMBER)
+  int err;
+
+  if (ldap_get_option (ld, LDAP_OPT_ERROR_NUMBER, &err) == 0)
+    return ldap_err_to_gpg_err (err);
+  else
+    return GPG_ERR_GENERAL;
+#elif defined(HAVE_LDAP_LD_ERRNO)
+  return ldap_err_to_gpg_err (ld->ld_errno);
+#else
+  /* We should never get here since the LDAP library should always
+     have either ldap_get_option or ld_errno, but just in case... */
+  return GPG_ERR_GENERAL;
+#endif
+}
+
+static time_t
+ldap2epochtime (const char *timestr)
+{
+  struct tm pgptime;
+  time_t answer;
+
+  memset (&pgptime, 0, sizeof(pgptime));
+
+  /* YYYYMMDDHHmmssZ */
+
+  sscanf (timestr, "%4d%2d%2d%2d%2d%2d",
+	  &pgptime.tm_year,
+	  &pgptime.tm_mon,
+	  &pgptime.tm_mday,
+	  &pgptime.tm_hour,
+	  &pgptime.tm_min,
+	  &pgptime.tm_sec);
+
+  pgptime.tm_year -= 1900;
+  pgptime.tm_isdst = -1;
+  pgptime.tm_mon--;
+
+  /* mktime() takes the timezone into account, so we use timegm() */
+
+  answer = timegm (&pgptime);
+
+  return answer;
+}
+
+/* Caller must free the result.  */
+static char *
+tm2ldaptime (struct tm *tm)
+{
+  struct tm tmp = *tm;
+  char buf[16];
+
+  /* YYYYMMDDHHmmssZ */
+
+  tmp.tm_year += 1900;
+  tmp.tm_mon ++;
+
+  sprintf (buf, "%04d%02d%02d%02d%02d%02dZ",
+	   tmp.tm_year,
+	   tmp.tm_mon,
+	   tmp.tm_mday,
+	   tmp.tm_hour,
+	   tmp.tm_min,
+	   tmp.tm_sec);
+
+  return xstrdup (buf);
+}
+
+#if 0
+/* Caller must free */
+static char *
+epoch2ldaptime (time_t stamp)
+{
+  struct tm tm;
+  if (gmtime_r (&stamp, &tm))
+    return tm2ldaptime (&tm);
+  else
+    return xstrdup ("INVALID TIME");
+}
+#endif
+
+/* Print a help output for the schemata supported by this module. */
+gpg_error_t
+ks_ldap_help (ctrl_t ctrl, parsed_uri_t uri)
+{
+  const char const data[] =
+    "Handler for LDAP URLs:\n"
+    "  ldap://host:port/[BASEDN]???[bindname=BINDNAME,password=PASSWORD]\n"
+    "\n"
+    "Note: basedn, bindname and password need to be percent escaped. In\n"
+    "particular, spaces need to be replaced with %20 and commas with %2c.\n"
+    "bindname will typically be of the form:\n"
+    "\n"
+    "  uid=user%2cou=PGP%20Users%2cdc=EXAMPLE%2cdc=ORG\n"
+    "\n"
+    "The ldaps:// and ldapi:// schemes are also supported.  If ldaps is used\n"
+    "then the server's certificate will be checked.  If it is not valid, any\n"
+    "operation will be aborted.\n"
+    "\n"
+    "Supported methods: search, get, put\n";
+  gpg_error_t err;
+
+  if (strcmp (uri->scheme, "ldap") == 0
+      || strcmp (uri->scheme, "ldaps") == 0
+      || strcmp (uri->scheme, "ldapi") == 0)
+    err = ks_print_help (ctrl, data);
+  else
+    err = 0;
+
+  return err;
+}
+
+/* Convert a keyspec to a filter.  Return an error if the keyspec is
+   bad or is not supported.  The filter is escaped and returned in
+   *filter.  It is the caller's responsibility to free *filter.
+   *filter is only set if this function returns success (i.e., 0).  */
+static gpg_error_t
+keyspec_to_ldap_filter (const char *keyspec, char **filter, int only_exact)
+{
+  /* Remove search type indicator and adjust PATTERN accordingly.
+     Note: don't include a preceding 0x when searching by keyid.  */
+
+  /* XXX: Should we include disabled / revoke options?  */
+  KEYDB_SEARCH_DESC desc;
+  char *f = NULL;
+
+  gpg_error_t err = classify_user_id (keyspec, &desc, 1);
+  if (err)
+    return err;
+
+  switch (desc.mode)
+    {
+    case KEYDB_SEARCH_MODE_EXACT:
+      f = xasprintf ("(pgpUserID=%s)",
+		     ldap_escape_filter (desc.u.name));
+      break;
+
+    case KEYDB_SEARCH_MODE_SUBSTR:
+      if (! only_exact)
+	f = xasprintf ("(pgpUserID=*%s*)",
+		       ldap_escape_filter (desc.u.name));
+      break;
+
+    case KEYDB_SEARCH_MODE_MAIL:
+      if (! only_exact)
+	f = xasprintf ("(pgpUserID=*<%s>*)",
+		       ldap_escape_filter (desc.u.name));
+      break;
+
+    case KEYDB_SEARCH_MODE_MAILSUB:
+      if (! only_exact)
+	f = xasprintf ("(pgpUserID=*<*%s*>*)",
+		       ldap_escape_filter (desc.u.name));
+      break;
+
+    case KEYDB_SEARCH_MODE_MAILEND:
+      if (! only_exact)
+	f = xasprintf ("(pgpUserID=*<*%s>*)",
+		       ldap_escape_filter (desc.u.name));
+      break;
+
+    case KEYDB_SEARCH_MODE_SHORT_KID:
+      f = xasprintf ("(pgpKeyID=%08lX)", (ulong) desc.u.kid[1]);
+      break;
+    case KEYDB_SEARCH_MODE_LONG_KID:
+      f = xasprintf ("(pgpCertID=%08lX%08lX)",
+		     (ulong) desc.u.kid[0], (ulong) desc.u.kid[1]);
+      break;
+
+    case KEYDB_SEARCH_MODE_FPR16:
+    case KEYDB_SEARCH_MODE_FPR20:
+    case KEYDB_SEARCH_MODE_FPR:
+    case KEYDB_SEARCH_MODE_ISSUER:
+    case KEYDB_SEARCH_MODE_ISSUER_SN:
+    case KEYDB_SEARCH_MODE_SN:
+    case KEYDB_SEARCH_MODE_SUBJECT:
+    case KEYDB_SEARCH_MODE_KEYGRIP:
+    case KEYDB_SEARCH_MODE_WORDS:
+    case KEYDB_SEARCH_MODE_FIRST:
+    case KEYDB_SEARCH_MODE_NEXT:
+    default:
+      break;
+    }
+
+  if (! f)
+    {
+      log_error ("Unsupported search mode.\n");
+      return gpg_error (GPG_ERR_NOT_SUPPORTED);
+    }
+
+  *filter = f;
+
+  return 0;
+}
+
+/* Connect to an LDAP server and interrogate it.
+
+     - uri describes the server to connect to and various options
+       including whether to use TLS and the username and password (see
+       ldap_parse_uri for a description of the various fields).
+
+   This function returns:
+
+     - The ldap connection handle in *LDAP_CONNP.
+
+     - The base DN for the PGP key space by querying the
+       pgpBaseKeySpaceDN attribute (This is normally
+       'ou=PGP Keys,dc=EXAMPLE,dc=ORG').
+
+     - The attribute to lookup to find the pgp key.  This is either
+       'pgpKey' or 'pgpKeyV2'.
+
+     - Whether this is a real ldap server.  (It's unclear what this
+       exactly means.)
+
+   The values are returned in the passed variables.  If you pass NULL,
+   then the value won't be returned.  It is the caller's
+   responsibility to release *LDAP_CONNP with ldap_unbind and xfree
+   *BASEDNP and *PGPKEYATTRP.
+
+   If this function successfully interrogated the server, it returns
+   0.  If there was an LDAP error, it returns the LDAP error code.  If
+   an error occured, *basednp, etc., are undefined (and don't need to
+   be freed.)
+
+   If no LDAP error occured, you still need to check that *basednp is
+   valid.  If it is NULL, then the server does not appear to be an
+   OpenPGP Keyserver.  In this case, you also do not need to free
+   *pgpkeyattrp.  */
+static int
+ldap_connect (parsed_uri_t uri, LDAP **ldap_connp,
+	      char **basednp, char **pgpkeyattrp, int *real_ldapp)
+{
+  int err = 0;
+
+  LDAP *ldap_conn = NULL;
+
+  char *user = uri->auth;
+  struct uri_tuple_s *password_param = uri_query_lookup (uri, "password");
+  char *password = password_param ? password_param->value : NULL;
+
+  char *basedn = NULL;
+  /* Whether to look for the pgpKey or pgpKeyv2 attribute.  */
+  char *pgpkeyattr = "pgpKey";
+  int real_ldap = 0;
+
+  log_debug ("ldap_connect(%s:%d/%s????%s%s%s%s%s)\n",
+	     uri->host, uri->port,
+	     uri->path ?: "",
+	     uri->auth ? "bindname=" : "", uri->auth ?: "",
+	     uri->auth && password ? "," : "",
+	     password ? "password=" : "", password ?: "");
+
+  /* If the uri specifies a secure connection and we don't support
+     TLS, then fail; don't silently revert to an insecure
+     connection.  */
+  if (uri->use_tls)
+    {
+#ifndef HAVE_LDAP_START_TLS_S
+      log_error ("Can't use LDAP to connect to the server: no TLS support.");
+      err = GPG_ERR_LDAP_NOT_SUPPORTED;
+      goto out;
+#endif
+    }
+
+  ldap_conn = ldap_init (uri->host, uri->port);
+  if (! ldap_conn)
+    {
+      log_error ("Failed to open connection to LDAP server (%s://%s:%d)\n",
+		 uri->scheme, uri->host, uri->port);
+      err = gpg_err_code_from_errno (errno);
+      goto out;
+    }
+
+#ifdef HAVE_LDAP_SET_OPTION
+  {
+    int ver = LDAP_VERSION3;
+
+    err = ldap_set_option (ldap_conn, LDAP_OPT_PROTOCOL_VERSION, &ver);
+    if (err != LDAP_SUCCESS)
+      {
+	log_error ("gpgkeys: unable to go to LDAP 3: %s\n",
+		   ldap_err2string (err));
+	goto out;
+      }
+  }
+#endif
+
+  /* XXX: It would be nice to have an option to provide the server's
+     certificate.  */
+#if 0
+#if defined(LDAP_OPT_X_TLS_CACERTFILE) && defined(HAVE_LDAP_SET_OPTION)
+  err = ldap_set_option (NULL, LDAP_OPT_X_TLS_CACERTFILE, ca_cert_file);
+  if (err)
+    {
+      log_error ("unable to set ca-cert-file to '%s': %s\n",
+		 ca_cert_file, ldap_err2string (err));
+      goto out;
+    }
+#endif /* LDAP_OPT_X_TLS_CACERTFILE && HAVE_LDAP_SET_OPTION */
+#endif
+
+#ifndef HAVE_LDAP_START_TLS_S
+  if (uri->use_tls)
+    {
+      /* XXX: We need an option to determine whether to abort if the
+	 certificate is bad or not.  Right now we conservatively
+	 default to checking the certificate and aborting.  */
+      int check_cert = LDAP_OPT_X_TLS_HARD; // LDAP_OPT_X_TLS_NEVER
+
+      err = ldap_set_option (ldap_conn,
+			     LDAP_OPT_X_TLS_REQUIRE_CERT, &check_cert);
+      if (err)
+	{
+	  log_error ("Failed to set TLS option on LDAP connection.\n");
+	  goto out;
+	}
+
+      err = ldap_start_tls_s (ldap_conn, NULL, NULL);
+      if (err)
+	{
+	  log_error ("Failed to connect to LDAP server with TLS.\n");
+	  goto out;
+	}
+    }
+#endif
+
+  /* By default we don't bind as there is usually no need to.  */
+  if (uri->auth)
+    {
+      log_debug ("LDAP bind to %s, password %s\n",
+		 user, password ? ">not shown<" : ">none<");
+
+      err = ldap_simple_bind_s (ldap_conn, user, password);
+      if (err != LDAP_SUCCESS)
+	{
+	  log_error ("Internal LDAP bind error: %s\n",
+		     ldap_err2string (err));
+	  goto out;
+	}
+    }
+
+  if (uri->path && *uri->path)
+    /* User specified base DN.  */
+    {
+      basedn = xstrdup (uri->path);
+
+      /* If the user specifies a base DN, then we know the server is a
+	 real LDAP server.  */
+      real_ldap = 1;
+    }
+  else
+    {
+      LDAPMessage *res = NULL;
+      /* Look for namingContexts.  */
+      char *attr[] = { "namingContexts", NULL };
+
+      err = ldap_search_s (ldap_conn, "", LDAP_SCOPE_BASE,
+			   "(objectClass=*)", attr, 0, &res);
+      if (err == LDAP_SUCCESS)
+	{
+	  char **context = ldap_get_values (ldap_conn, res, "namingContexts");
+	  if (context)
+	    /* We found some, so try each namingContext as the search
+	       base and look for pgpBaseKeySpaceDN.  Because we found
+	       this, we know we're talking to a regular-ish LDAP
+	       server and not an LDAP keyserver.  */
+	    {
+	      int i;
+	      char *attr2[] =
+		{ "pgpBaseKeySpaceDN", "pgpVersion", "pgpSoftware", NULL };
+
+	      real_ldap = 1;
+
+	      for (i = 0; context[i] && ! basedn; i++)
+		{
+		  char **vals;
+		  LDAPMessage *si_res;
+
+		  char *object = xasprintf ("cn=pgpServerInfo,%s", context[i]);
+		  err = ldap_search_s (ldap_conn, object, LDAP_SCOPE_BASE,
+				       "(objectClass=*)", attr2, 0, &si_res);
+		  free (object);
+
+		  if (err == LDAP_SUCCESS)
+		    {
+		      vals = ldap_get_values (ldap_conn, si_res,
+					      "pgpBaseKeySpaceDN");
+		      if (vals)
+			{
+			  basedn = strdup (vals[0]);
+			  ldap_value_free (vals);
+			}
+
+		      vals = ldap_get_values (ldap_conn, si_res,
+					      "pgpSoftware");
+		      if (vals)
+			{
+			  log_debug ("Server: \t%s\n", vals[0]);
+			  ldap_value_free (vals);
+			}
+
+		      vals = ldap_get_values (ldap_conn, si_res,
+					      "pgpVersion");
+		      if (vals)
+			{
+			  log_debug ("Version:\t%s\n", vals[0]);
+			  ldap_value_free (vals);
+			}
+		    }
+
+		  /* From man ldap_search_s: "res parameter of
+		     ldap_search_ext_s() and ldap_search_s() should be
+		     freed with ldap_msgfree() regardless of return
+		     value of these functions.  */
+		  ldap_msgfree (si_res);
+		}
+
+	      ldap_value_free (context);
+	    }
+	}
+      else
+	{
+	  /* We don't have an answer yet, which means the server might
+	     be an LDAP keyserver. */
+	  char **vals;
+	  LDAPMessage *si_res = NULL;
+
+	  char *attr2[] = { "pgpBaseKeySpaceDN", "version", "software", NULL };
+
+	  err = ldap_search_s (ldap_conn, "cn=pgpServerInfo", LDAP_SCOPE_BASE,
+			       "(objectClass=*)", attr2, 0, &si_res);
+	  if (err == LDAP_SUCCESS)
+	    {
+	      /* For the LDAP keyserver, this is always
+		 "OU=ACTIVE,O=PGP KEYSPACE,C=US", but it might not be
+		 in the future. */
+
+	      vals = ldap_get_values (ldap_conn, si_res, "baseKeySpaceDN");
+	      if (vals)
+		{
+		  basedn = strdup (vals[0]);
+		  ldap_value_free (vals);
+		}
+
+	      vals = ldap_get_values (ldap_conn, si_res, "software");
+	      if (vals)
+		{
+		  log_debug ("ldap: Server: \t%s\n", vals[0]);
+		  ldap_value_free (vals);
+		}
+
+	      vals = ldap_get_values (ldap_conn, si_res, "version");
+	      if (vals)
+		{
+		  log_debug ("ldap: Version:\t%s\n", vals[0]);
+
+		  /* If the version is high enough, use the new
+		     pgpKeyV2 attribute.  This design is iffy at best,
+		     but it matches how PGP does it.  I figure the NAI
+		     folks assumed that there would never be an LDAP
+		     keyserver vendor with a different numbering
+		     scheme. */
+		  if (atoi (vals[0]) > 1)
+		    pgpkeyattr = "pgpKeyV2";
+
+		  ldap_value_free (vals);
+		}
+	    }
+
+	  ldap_msgfree (si_res);
+	}
+
+      /* From man ldap_search_s: "res parameter of ldap_search_ext_s()
+	 and ldap_search_s() should be freed with ldap_msgfree()
+	 regardless of return value of these functions.  */
+      ldap_msgfree (res);
+    }
+
+ out:
+  if (! err)
+    {
+      log_debug ("ldap_conn: %p\n", ldap_conn);
+      log_debug ("real_ldap: %d\n", real_ldap);
+      log_debug ("basedn: %s\n", basedn);
+      log_debug ("pgpkeyattr: %s\n", pgpkeyattr);
+    }
+
+  if (! err && real_ldapp)
+    *real_ldapp = real_ldap;
+
+  if (err)
+    xfree (basedn);
+  else
+    {
+      if (pgpkeyattrp)
+	{
+	  if (basedn)
+	    *pgpkeyattrp = xstrdup (pgpkeyattr);
+	  else
+	    *pgpkeyattrp = NULL;
+	}
+
+      if (basednp)
+	*basednp = basedn;
+      else
+	xfree (basedn);
+    }
+
+  if (err)
+    {
+      if (ldap_conn)
+	ldap_unbind (ldap_conn);
+    }
+  else
+    *ldap_connp = ldap_conn;
+
+  return err;
+}
+
+/* Extract keys from an LDAP reply and write them out to the output
+   stream OUTPUT in a format GnuPG can import (either the OpenPGP
+   binary format or armored format).  */
+static void
+extract_keys (estream_t output,
+	      LDAP *ldap_conn, const char *certid, LDAPMessage *message)
+{
+  char **vals;
+
+  es_fprintf (output, "INFO %s BEGIN\n", certid);
+  es_fprintf (output, "pub:%s:", certid);
+
+  /* Note: ldap_get_values returns a NULL terminates array of
+     strings.  */
+  vals = ldap_get_values (ldap_conn, message, "pgpkeytype");
+  if (vals && vals[0])
+    {
+      if (strcmp (vals[0], "RSA") == 0)
+	es_fprintf  (output, "1");
+      else if (strcmp (vals[0],"DSS/DH") == 0)
+	es_fprintf (output, "17");
+      ldap_value_free (vals);
+    }
+
+  es_fprintf (output, ":");
+
+  vals = ldap_get_values (ldap_conn, message, "pgpkeysize");
+  if (vals && vals[0])
+    {
+      int v = atoi (vals[0]);
+      if (v > 0)
+	es_fprintf (output, "%d", v);
+      ldap_value_free (vals);
+    }
+
+  es_fprintf (output, ":");
+
+  vals = ldap_get_values (ldap_conn, message, "pgpkeycreatetime");
+  if (vals && vals[0])
+    {
+      if (strlen (vals[0]) == 15)
+	es_fprintf (output, "%u", (unsigned int) ldap2epochtime (vals[0]));
+      ldap_value_free (vals);
+    }
+
+  es_fprintf (output, ":");
+
+  vals = ldap_get_values (ldap_conn, message, "pgpkeyexpiretime");
+  if (vals && vals[0])
+    {
+      if (strlen (vals[0]) == 15)
+	es_fprintf (output, "%u", (unsigned int) ldap2epochtime (vals[0]));
+      ldap_value_free (vals);
+    }
+
+  es_fprintf (output, ":");
+
+  vals = ldap_get_values (ldap_conn, message, "pgprevoked");
+  if (vals && vals[0])
+    {
+      if (atoi (vals[0]) == 1)
+	es_fprintf (output, "r");
+      ldap_value_free (vals);
+    }
+
+  es_fprintf (output, "\n");
+
+  vals = ldap_get_values (ldap_conn, message, "pgpuserid");
+  if (vals && vals[0])
+    {
+      int i;
+      for (i = 0; vals[i]; i++)
+	es_fprintf (output, "uid:%s\n", vals[i]);
+      ldap_value_free (vals);
+    }
+
+  es_fprintf (output, "INFO %s END\n", certid);
+}
+
+/* Get the key described key the KEYSPEC string from the keyserver
+   identified by URI.  On success R_FP has an open stream to read the
+   data.  */
+gpg_error_t
+ks_ldap_get (ctrl_t ctrl, parsed_uri_t uri, const char *keyspec,
+	     estream_t *r_fp)
+{
+  gpg_error_t err = 0;
+  int ldap_err;
+
+  char *filter = NULL;
+
+  LDAP *ldap_conn = NULL;
+
+  char *basedn = NULL;
+  char *pgpkeyattr = NULL;
+
+  estream_t fp = NULL;
+
+  LDAPMessage *message = NULL;
+
+  (void) ctrl;
+
+  /* Before connecting to the server, make sure we have a sane
+     keyspec.  If not, there is no need to establish a network
+     connection.  */
+  err = keyspec_to_ldap_filter (keyspec, &filter, 1);
+  if (err)
+    return (err);
+
+  /* Make sure we are talking to an OpenPGP LDAP server.  */
+  ldap_err = ldap_connect (uri, &ldap_conn, &basedn, &pgpkeyattr, NULL);
+  if (ldap_err || !basedn)
+    {
+      if (ldap_err)
+	err = ldap_err_to_gpg_err (ldap_err);
+      else
+	err = GPG_ERR_GENERAL;
+      goto out;
+    }
+
+  {
+    /* The ordering is significant.  Specifically, "pgpcertid" needs
+       to be the second item in the list, since everything after it
+       may be discarded we aren't in verbose mode. */
+    char *attrs[] =
+      {
+	pgpkeyattr,
+	"pgpcertid", "pgpuserid", "pgpkeyid", "pgprevoked", "pgpdisabled",
+	"pgpkeycreatetime", "modifytimestamp", "pgpkeysize", "pgpkeytype",
+	NULL
+      };
+    /* 1 if we want just attribute types; 0 if we want both attribute
+       types and values.  */
+    int attrsonly = 0;
+
+    int count;
+
+    ldap_err = ldap_search_s (ldap_conn, basedn, LDAP_SCOPE_SUBTREE,
+			      filter, attrs, attrsonly, &message);
+    if (ldap_err)
+      {
+	err = ldap_err_to_gpg_err (ldap_err);
+
+	log_error ("gpgkeys: LDAP search error: %s\n",
+		   ldap_err2string (ldap_err));
+	goto out;
+      }
+
+    count = ldap_count_entries (ldap_conn, message);
+    if (count < 1)
+      {
+	log_error ("gpgkeys: key %s not found on keyserver\n", keyspec);
+
+	if (count == -1)
+	  err = ldap_to_gpg_err (ldap_conn);
+	else
+	  err = gpg_error (GPG_ERR_NO_DATA);
+
+	goto out;
+      }
+
+    {
+      /* There may be more than one unique result for a given keyID,
+	 so we should fetch them all (test this by fetching short key
+	 id 0xDEADBEEF). */
+
+      /* The set of entries that we've seen.  */
+      strlist_t seen = NULL;
+      LDAPMessage *each;
+
+      for (each = ldap_first_entry (ldap_conn, message);
+	   each;
+	   each = ldap_next_entry (ldap_conn, each))
+	{
+	  char **vals;
+	  char **certid;
+
+	  /* Use the long keyid to remove duplicates.  The LDAP
+	     server returns the same keyid more than once if there
+	     are multiple user IDs on the key.  Note that this does
+	     NOT mean that a keyid that exists multiple times on the
+	     keyserver will not be fetched.  It means that each KEY,
+	     no matter how many user IDs share its keyid, will be
+	     fetched only once.  If a keyid that belongs to more
+	     than one key is fetched, the server quite properly
+	     responds with all matching keys. -ds */
+
+	  certid = ldap_get_values (ldap_conn, each, "pgpcertid");
+	  if (certid && certid[0])
+	    {
+	      if (! strlist_find (seen, certid[0]))
+		{
+		  /* It's not a duplicate, add it */
+
+		  add_to_strlist (&seen, certid[0]);
+
+		  if (! fp)
+		    fp = es_fopenmem(0, "rw");
+
+		  extract_keys (fp, ldap_conn, certid[0], each);
+
+		  vals = ldap_get_values (ldap_conn, each, pgpkeyattr);
+		  if (! vals)
+		    {
+		      err = ldap_to_gpg_err (ldap_conn);
+		      log_error("gpgkeys: unable to retrieve key %s "
+				"from keyserver\n", certid[0]);
+		      goto out;
+		    }
+		  else
+		    {
+		      /* We should strip the new lines.  */
+		      es_fprintf (fp, "KEY 0x%s BEGIN\n", certid[0]);
+		      es_fputs (vals[0], fp);
+		      es_fprintf (fp, "\nKEY 0x%s END\n", certid[0]);
+
+		      ldap_value_free (vals);
+		    }
+		}
+	    }
+
+	  ldap_value_free (certid);
+	}
+
+      free_strlist (seen);
+
+      if (! fp)
+	err = gpg_error (GPG_ERR_NO_DATA);
+    }
+  }
+
+ out:
+  if (message)
+    ldap_msgfree (message);
+
+  if (err)
+    {
+      if (fp)
+	es_fclose (fp);
+    }
+  else
+    {
+      if (fp)
+	es_fseek (fp, 0, SEEK_SET);
+
+      *r_fp = fp;
+    }
+
+  xfree (pgpkeyattr);
+  xfree (basedn);
+
+  if (ldap_conn)
+    ldap_unbind (ldap_conn);
+
+  xfree (filter);
+
+  return err;
+}
+
+/* Search the keyserver identified by URI for keys matching PATTERN.
+   On success R_FP has an open stream to read the data.  */
+gpg_error_t
+ks_ldap_search (ctrl_t ctrl, parsed_uri_t uri, const char *pattern,
+		estream_t *r_fp)
+{
+  gpg_error_t err;
+  int ldap_err;
+
+  char *filter = NULL;
+
+  LDAP *ldap_conn = NULL;
+
+  char *basedn = NULL;
+
+  estream_t fp = NULL;
+
+  (void) ctrl;
+
+  /* Before connecting to the server, make sure we have a sane
+     keyspec.  If not, there is no need to establish a network
+     connection.  */
+  err = keyspec_to_ldap_filter (pattern, &filter, 0);
+  if (err)
+    {
+      log_error ("Bad search pattern: '%s'\n", pattern);
+      return (err);
+    }
+
+  /* Make sure we are talking to an OpenPGP LDAP server.  */
+  ldap_err = ldap_connect (uri, &ldap_conn, &basedn, NULL, NULL);
+  if (ldap_err || !basedn)
+    {
+      if (ldap_err)
+	err = ldap_err_to_gpg_err (ldap_err);
+      else
+	err = GPG_ERR_GENERAL;
+      goto out;
+    }
+
+  /* Even if we have no results, we want to return a stream.  */
+  fp = es_fopenmem(0, "rw");
+
+  {
+    char **vals;
+    LDAPMessage *res, *each;
+    int count = 0;
+    strlist_t dupelist = NULL;
+
+    /* The maximum size of the search, including the optional stuff
+       and the trailing \0 */
+    char *attrs[] =
+      {
+	"pgpcertid", "pgpuserid", "pgprevoked", "pgpdisabled",
+	"pgpkeycreatetime", "pgpkeyexpiretime", "modifytimestamp",
+	"pgpkeysize", "pgpkeytype", NULL
+      };
+
+    log_debug ("SEARCH '%s' => '%s' BEGIN\n", pattern, filter);
+
+    ldap_err = ldap_search_s (ldap_conn, basedn,
+			      LDAP_SCOPE_SUBTREE, filter, attrs, 0, &res);
+
+    xfree (filter);
+    filter = NULL;
+
+    if (err != LDAP_SUCCESS && err != LDAP_SIZELIMIT_EXCEEDED)
+      {
+	err = ldap_err_to_gpg_err (ldap_err);
+
+	log_error ("SEARCH %s FAILED %d\n", pattern, err);
+	log_error ("gpgkeys: LDAP search error: %s\n",
+		   ldap_err2string (err));
+	goto out;
+    }
+
+    /* The LDAP server doesn't return a real count of unique keys, so we
+       can't use ldap_count_entries here. */
+    for (each = ldap_first_entry (ldap_conn, res);
+	 each;
+	 each = ldap_next_entry (ldap_conn, each))
+      {
+	char **certid = ldap_get_values (ldap_conn, each, "pgpcertid");
+	if (certid && certid[0] && ! strlist_find (dupelist, certid[0]))
+	  {
+	    add_to_strlist (&dupelist, certid[0]);
+	    count++;
+	  }
+      }
+
+    if (err == LDAP_SIZELIMIT_EXCEEDED)
+      {
+	if (count == 1)
+	  log_error ("gpgkeys: search results exceeded server limit."
+		     "  First 1 result shown.\n");
+	else
+	  log_error ("gpgkeys: search results exceeded server limit."
+		     "  First %d results shown.\n", count);
+      }
+
+    free_strlist (dupelist);
+    dupelist = NULL;
+
+    if (count < 1)
+      es_fputs ("info:1:0\n", fp);
+    else
+      {
+	es_fprintf (fp, "info:1:%d\n", count);
+
+	for (each = ldap_first_entry (ldap_conn, res);
+	     each;
+	     each = ldap_next_entry (ldap_conn, each))
+	  {
+	    char **certid;
+	    LDAPMessage *uids;
+
+	    certid = ldap_get_values (ldap_conn, each, "pgpcertid");
+	    if (! certid || ! certid[0])
+	      continue;
+
+	    /* Have we seen this certid before? */
+	    if (! strlist_find (dupelist, certid[0]))
+	      {
+		add_to_strlist (&dupelist, certid[0]);
+
+		es_fprintf (fp, "pub:%s:",certid[0]);
+
+		  vals = ldap_get_values (ldap_conn, each, "pgpkeytype");
+		  if (vals)
+		    {
+		      /* The LDAP server doesn't exactly handle this
+			 well. */
+		      if (strcasecmp (vals[0], "RSA") == 0)
+			es_fputs ("1", fp);
+		      else if (strcasecmp (vals[0], "DSS/DH") == 0)
+			es_fputs ("17", fp);
+		      ldap_value_free (vals);
+		    }
+
+		  es_fputc (':', fp);
+
+		  vals = ldap_get_values (ldap_conn, each, "pgpkeysize");
+		  if (vals)
+		    {
+		      /* Not sure why, but some keys are listed with a
+			 key size of 0.  Treat that like an
+			 unknown. */
+		      if (atoi (vals[0]) > 0)
+			es_fprintf (fp, "%d", atoi (vals[0]));
+		      ldap_value_free (vals);
+		    }
+
+		  es_fputc (':', fp);
+
+		  /* YYYYMMDDHHmmssZ */
+
+		  vals = ldap_get_values (ldap_conn, each, "pgpkeycreatetime");
+		  if(vals && strlen (vals[0]) == 15)
+		    {
+		      es_fprintf (fp, "%u",
+				  (unsigned int) ldap2epochtime(vals[0]));
+		      ldap_value_free (vals);
+		    }
+
+		  es_fputc (':', fp);
+
+		  vals = ldap_get_values (ldap_conn, each, "pgpkeyexpiretime");
+		  if (vals && strlen (vals[0]) == 15)
+		    {
+		      es_fprintf (fp, "%u",
+				  (unsigned int) ldap2epochtime (vals[0]));
+		      ldap_value_free (vals);
+		    }
+
+		  es_fputc (':', fp);
+
+		  vals = ldap_get_values (ldap_conn, each, "pgprevoked");
+		  if (vals)
+		    {
+		      if (atoi (vals[0]) == 1)
+			es_fprintf (fp, "r");
+		      ldap_value_free (vals);
+		    }
+
+		  vals = ldap_get_values (ldap_conn, each, "pgpdisabled");
+		  if (vals)
+		    {
+		      if (atoi (vals[0]) ==1)
+			es_fprintf (fp, "d");
+		      ldap_value_free (vals);
+		    }
+
+#if 0
+		  /* This is not yet specified in the keyserver
+		     protocol, but may be someday. */
+		  es_fputc (':', fp);
+
+		  vals = ldap_get_values (ldap_conn, each, "modifytimestamp");
+		  if(vals && strlen (vals[0]) == 15)
+		    {
+		      es_fprintf (fp, "%u",
+				  (unsigned int) ldap2epochtime (vals[0]));
+		      ldap_value_free (vals);
+		    }
+#endif
+
+		  es_fprintf (fp, "\n");
+
+		  /* Now print all the uids that have this certid */
+		  for (uids = ldap_first_entry (ldap_conn, res);
+		       uids;
+		       uids = ldap_next_entry (ldap_conn, uids))
+		    {
+		      vals = ldap_get_values (ldap_conn, uids, "pgpcertid");
+		      if (! vals)
+			continue;
+
+		      if (strcasecmp (certid[0], vals[0]) == 0)
+			{
+			  char **uidvals;
+
+			  es_fprintf (fp, "uid:");
+
+			  uidvals = ldap_get_values (ldap_conn,
+						     uids, "pgpuserid");
+			  if (uidvals)
+			    {
+			      /* Need to escape any colons */
+			      char *quoted = percent_escape (uidvals[0], NULL);
+			      es_fputs (quoted, fp);
+			      xfree (quoted);
+			      ldap_value_free (uidvals);
+			    }
+
+			  es_fprintf (fp, "\n");
+			}
+
+		      ldap_value_free(vals);
+		    }
+	      }
+
+	      ldap_value_free (certid);
+	  }
+      }
+
+    ldap_msgfree (res);
+    free_strlist (dupelist);
+  }
+
+  log_debug ("SEARCH %s END\n", pattern);
+
+ out:
+  if (err)
+    {
+      if (fp)
+	es_fclose (fp);
+    }
+  else
+    {
+      /* Return the read stream.  */
+      if (fp)
+	es_fseek (fp, 0, SEEK_SET);
+
+      *r_fp = fp;
+    }
+
+  xfree (basedn);
+
+  if (ldap_conn)
+    ldap_unbind (ldap_conn);
+
+  xfree (filter);
+
+  return err;
+}
+
+/* A modlist describes a set of changes to an LDAP entry.  (An entry
+   consists of 1 or more attributes.  Attributes are <name, value>
+   pairs.  Note: an attribute may be multi-valued in which case
+   multiple values are associated with a single name.)
+
+   A modlist is a NULL terminated array of struct LDAPMod's.
+
+   Thus, if we have:
+
+     LDAPMod **modlist;
+
+   Then:
+
+     modlist[i]
+
+   Is the ith modification.
+
+   Each LDAPMod describes a change to a single attribute.  Further,
+   there is one modification for each attribute that we want to
+   change.  The attribute's new value is stored in LDAPMod.mod_values.
+   If the attribute is multi-valued, we still only use a single
+   LDAPMod structure: mod_values is a NULL-terminated array of
+   strings.  To delete an attribute from an entry, we set mod_values
+   to NULL.
+
+   Thus, if:
+
+     modlist[i]->mod_values == NULL
+
+   then we remove the attribute.
+
+   (Using LDAP_MOD_DELETE doesn't work here as we don't know if the
+   attribute in question exists or not.)
+
+   Note: this function does NOT copy or free ATTR.  It does copy
+   VALUE.  */
+static void
+modlist_add (LDAPMod ***modlistp, char *attr, const char *value)
+{
+  LDAPMod **modlist = *modlistp;
+
+  LDAPMod **m;
+  int nummods = 0;
+
+  /* Search modlist for the attribute we're playing with.  If modlist
+     is NULL, then the list is empty.  Recall: modlist is a NULL
+     terminated array.  */
+  for (m = modlist; m && *m; m++, nummods ++)
+    {
+      /* The attribute is already on the list.  */
+      char **ptr;
+      int numvalues = 0;
+
+      if (strcasecmp ((*m)->mod_type, attr) != 0)
+	continue;
+
+      /* We have this attribute already, so when the REPLACE happens,
+	 the server attributes will be replaced anyway. */
+      if (! value)
+	return;
+
+      /* Attributes can be multi-valued.  See if the value is already
+	 present.  mod_values is a NULL terminated array of pointers.
+	 Note: mod_values can be NULL.  */
+      for (ptr = (*m)->mod_values; ptr && *ptr; ptr++)
+	{
+	  if (strcmp (*ptr, value) == 0)
+	    /* Duplicate value, we're done.  */
+	    return;
+	  numvalues ++;
+	}
+
+      /* Append the value.  */
+      ptr = xrealloc ((*m)->mod_values, sizeof (char *) * (numvalues + 2));
+
+      (*m)->mod_values = ptr;
+      ptr[numvalues] = xstrdup (value);
+
+      ptr[numvalues + 1] = NULL;
+
+      return;
+    }
+
+  /* We didn't find the attr, so make one and add it to the end */
+
+  /* Like attribute values, the list of attributes is NULL terminated
+     array of pointers.  */
+  modlist = xrealloc (modlist, sizeof (LDAPMod *) * (nummods + 2));
+
+  *modlistp = modlist;
+  modlist[nummods] = xmalloc (sizeof (LDAPMod));
+
+  modlist[nummods]->mod_op = LDAP_MOD_REPLACE;
+  modlist[nummods]->mod_type = attr;
+  if (value)
+    {
+      modlist[nummods]->mod_values = xmalloc (sizeof(char *) * 2);
+
+      /* XXX: Is this the right thing?  Can a UTF8-encoded user ID
+	 have embedded nulls? */
+      modlist[nummods]->mod_values[0] = xstrdup (value);
+      modlist[nummods]->mod_values[1] = NULL;
+    }
+  else
+    modlist[nummods]->mod_values = NULL;
+
+  modlist[nummods + 1] = NULL;
+
+  return;
+}
+
+/* Look up the value of an attribute in the specified modlist.  If the
+   attribute is not on the mod list, returns NULL.  The result is a
+   NULL-terminated array of strings.  Don't change it.  */
+static char **
+modlist_lookup (LDAPMod **modlist, const char *attr)
+{
+  LDAPMod **m;
+  for (m = modlist; m && *m; m++)
+    {
+      if (strcasecmp ((*m)->mod_type, attr) != 0)
+	continue;
+
+      return (*m)->mod_values;
+    }
+
+  return NULL;
+}
+
+/* Dump a modlist to a file.  This is useful for debugging.  */
+static estream_t modlist_dump (LDAPMod **modlist, estream_t output)
+  __attribute__ ((used));
+
+static estream_t
+modlist_dump (LDAPMod **modlist, estream_t output)
+{
+  LDAPMod **m;
+
+  int opened = 0;
+  if (! output)
+    {
+      output = es_fopenmem (0, "rw");
+      opened = 1;
+    }
+
+  for (m = modlist; m && *m; m++)
+    {
+      es_fprintf (output, "  %s:", (*m)->mod_type);
+
+      if (! (*m)->mod_values)
+	es_fprintf(output, " delete.\n");
+      else
+	{
+	  char **ptr;
+	  int i;
+
+	  int multi = 0;
+	  if ((*m)->mod_values[0] && (*m)->mod_values[1])
+	    /* Have at least 2.  */
+	    multi = 1;
+
+	  if (multi)
+	    es_fprintf (output, "\n");
+
+	  for ((ptr = (*m)->mod_values), (i = 1); ptr && *ptr; ptr++, i ++)
+	    {
+	      /* At most about 10 lines.  */
+	      const int max_len = 10 * 70;
+	      size_t value_len = strlen (*ptr);
+	      char buffer[max_len + 4];
+	      char *temp;
+	      int elided = 0;
+	      if (value_len > max_len)
+		{
+		  temp = buffer;
+		  memcpy (temp, *ptr, max_len);
+		  temp[max_len] = temp[max_len + 1] = temp[max_len + 2] = '.';
+		  temp[max_len + 3] = 0;
+		  elided = 1;
+		}
+	      else
+		temp = *ptr;
+
+	      if (multi)
+		es_fprintf (output, "    %d. ", i);
+	      es_fprintf (output, "`%s'", temp);
+	      if (elided)
+		es_fprintf (output, " (%zd bytes elided)",
+			    value_len - max_len);
+	      es_fprintf (output, "\n");
+	    }
+	}
+    }
+
+  if (opened)
+    es_fseek (output, 0, SEEK_SET);
+
+  return output;
+}
+
+/* Free all of the memory allocated by the mod list.  This assumes
+   that the attribute names don't have to be freed, but the attributes
+   values do.  (Which is what modlist_add does.)  */
+static void
+modlist_free (LDAPMod **modlist)
+{
+  LDAPMod **ml;
+
+  if (! modlist)
+    return;
+
+  /* Unwind and free the whole modlist structure */
+
+  /* The modlist is a NULL terminated array of pointers.  */
+  for (ml = modlist; *ml; ml++)
+    {
+      LDAPMod *mod = *ml;
+      char **ptr;
+
+      /* The list of values is a NULL termianted array of pointers.
+	 If the list is NULL, there are no values.  */
+
+      if (mod->mod_values)
+	{
+	  for (ptr = mod->mod_values; *ptr; ptr++)
+	    free (*ptr);
+
+	  free (mod->mod_values);
+	}
+
+      free (mod);
+    }
+  free (modlist);
+}
+
+/* Append two onto the end of one.  Two is not freed, but its pointers
+   are now part of one.  Make sure you don't free them both!
+
+   As long as you don't add anything to ONE, TWO is still valid.
+   After that all bets are off.  */
+static void
+modlists_join (LDAPMod ***one, LDAPMod **two)
+{
+  int i, one_count = 0, two_count = 0;
+  LDAPMod **grow;
+
+  if (!*two)
+    /* two is empty.  Nothing to do.  */
+    return;
+
+  if (!*one)
+    /* one is empty.  Just set it equal to *two.  */
+    {
+      *one = two;
+      return;
+    }
+
+  for (grow = *one; *grow; grow++)
+    one_count ++;
+
+  for (grow = two; *grow; grow++)
+    two_count ++;
+
+  grow = xrealloc (*one, sizeof(LDAPMod *) * (one_count + two_count + 1));
+
+  for (i = 0; i < two_count; i++)
+    grow[one_count + i] = two[i];
+
+  grow[one_count + i] = NULL;
+
+  *one = grow;
+}
+
+/* Given a string, unescape C escapes.  In particular, \xXX.  This
+   modifies the string in place.  */
+static void
+uncescape (char *str)
+{
+  int r = 0;
+  int w = 0;
+
+  char *first = strchr (str, '\\');
+  if (! first)
+    /* No backslashes => no escaping.  We're done.  */
+    return;
+
+  /* Start at the first '\\'.  */
+  r = w = (uintptr_t) first - (uintptr_t) str;
+
+  while (str[r])
+    {
+      /* XXX: What to do about bad escapes?  */
+      if (str[r] == '\\' && str[r + 1] == 'x'
+	  && (('0' <= str[r + 2] && str[r + 2] <= '9')
+	      || ('a' <= str[r + 2] && str[r + 2] <= 'f')
+	      || ('A' <= str[r + 2] && str[r + 2] <= 'F'))
+	  && (('0' <= str[r + 3] && str[r + 3] <= '9')
+	      || ('a' <= str[r + 3] && str[r + 3] <= 'f')
+	      || ('A' <= str[r + 3] && str[r + 3] <= 'F')))
+	{
+	  int x = hextobyte (&str[r + 2]);
+	  assert (0 <= x && x <= 0xff);
+
+	  str[w] = x;
+
+	  /* We consumed 4 characters and wrote 1.  */
+	  r += 4;
+	  w ++;
+	}
+      else
+	str[w ++] = str[r ++];
+    }
+
+  str[w] = '\0';
+}
+
+/* Given one line from an info block (`gpg --list-{keys,sigs}
+   --with-colons KEYID'), pull it apart and fill in the modlist with
+   the relevant (for the LDAP schema) attributes.  */
+static void
+extract_attributes (LDAPMod ***modlist, char *line)
+{
+  int i;
+
+  int field_count;
+  char **fields;
+
+  char *keyid;
+
+  int is_pub, is_sub, is_uid, is_sig;
+
+  /* Remove trailing whitespace */
+  for (i = strlen (line) - 1; i >= 0 && ascii_isspace (line[i]); i--)
+    line[i] = '\0';
+
+  fields = strsplit (line, ':', '\0', &field_count);
+  if (field_count == 1)
+    /* We only have a single field.  There is definately nothing to
+       do.  */
+    goto out;
+
+  if (field_count < 7)
+    goto out;
+
+  is_pub = strcasecmp ("pub", fields[0]) == 0;
+  is_sub = strcasecmp ("sub", fields[0]) == 0;
+  is_uid = strcasecmp ("uid", fields[0]) == 0;
+  is_sig = strcasecmp ("sig", fields[0]) == 0;
+
+  if (!is_pub && !is_sub && !is_uid && !is_sig)
+    /* Not a relevant line.  */
+    goto out;
+
+  keyid = fields[4];
+
+  if (is_uid && strlen (keyid) == 0)
+    /* The uid record type can have an empty keyid.  */
+    ;
+  else if (strlen (keyid) == 16
+	   && strspn (keyid, "0123456789aAbBcCdDeEfF") == 16)
+    /* Otherwise, we expect exactly 16 hex characters.  */
+    ;
+  else
+    {
+      log_error ("malformed record!\n");
+      goto out;
+    }
+
+  if (is_pub)
+    {
+      int disabled = 0, revoked = 0;
+      char *flags;
+      for (flags = fields[1]; *flags; flags ++)
+	switch (*flags)
+	  {
+	  case 'r':
+	  case 'R':
+	    revoked = 1;
+	    break;
+
+	  case 'd':
+	  case 'D':
+	    disabled = 1;
+	    break;
+	  }
+
+      /* Note: we always create the pgpDisabled and pgpRevoked
+	attributes, regardless of whether the key is disabled/revoked
+	or not.  This is because a very common search is like
+	"(&(pgpUserID=*isabella*)(pgpDisabled=0))"  */
+
+      if (is_pub)
+	{
+	  modlist_add (modlist,"pgpDisabled", disabled ? "1" : "0");
+	  modlist_add (modlist,"pgpRevoked", revoked ? "1" : "0");
+	}
+    }
+
+  if (is_pub || is_sub)
+    {
+      char *size = fields[2];
+      int val = atoi (size);
+      size = NULL;
+
+      if (val > 0)
+	{
+	  /* We zero pad this on the left to make PGP happy. */
+	  char padded[6];
+	  if (val < 99999 && val > 0)
+	    {
+	      sprintf (padded, "%05u", val);
+	      size = padded;
+	    }
+	}
+
+      if (size)
+	{
+	  if (is_pub || is_sub)
+	    modlist_add (modlist, "pgpKeySize", size);
+	}
+    }
+
+  if (is_pub)
+    {
+      char *algo = fields[3];
+      int val = atoi (algo);
+      switch (val)
+	{
+	case 1:
+	  algo = "RSA";
+	  break;
+
+	case 17:
+	  algo = "DSS/DH";
+	  break;
+
+	default:
+	  algo = NULL;
+	  break;
+	}
+
+      if (algo)
+	{
+	  if (is_pub)
+	    modlist_add (modlist, "pgpKeyType", algo);
+	}
+    }
+
+  if (is_pub || is_sub || is_sig)
+    {
+      if (is_pub)
+	{
+	  modlist_add (modlist, "pgpCertID", keyid);
+	  modlist_add (modlist, "pgpKeyID", &keyid[8]);
+	}
+
+      if (is_sub)
+	modlist_add (modlist, "pgpSubKeyID", keyid);
+
+      if (is_sig)
+	modlist_add (modlist, "pgpSignerID", keyid);
+    }
+
+  if (is_pub)
+    {
+      char *create_time = fields[5];
+
+      if (strlen (create_time) == 0)
+	create_time = NULL;
+      else
+	{
+	  char *create_time_orig = create_time;
+	  struct tm tm;
+	  time_t t;
+	  char *end;
+
+	  memset (&tm, 0, sizeof (tm));
+
+	  /* parse_timestamp handles both seconds fromt he epoch and
+	     ISO 8601 format.  We also need to handle YYYY-MM-DD
+	     format (as generated by gpg1 --with-colons --list-key).
+	     Check that first and then if it fails, then try
+	     parse_timestamp.  */
+
+	  if (strptime (create_time, "%Y-%m-%d", &tm))
+	    create_time = tm2ldaptime (&tm);
+	  else if ((t = parse_timestamp (create_time, &end)) != (time_t) -1
+		   && *end == '\0')
+	    {
+	      if (! gmtime_r (&t, &tm))
+		create_time = NULL;
+	      else
+		create_time = tm2ldaptime (&tm);
+	    }
+	  else
+	    create_time = NULL;
+
+	  if (! create_time)
+	    /* Failed to parse string.  */
+	    log_error ("Failed to parse creation time ('%s')",
+		       create_time_orig);
+	}
+
+      if (create_time)
+	{
+	  modlist_add (modlist, "pgpKeyCreateTime", create_time);
+	  xfree (create_time);
+	}
+    }
+
+  if (is_pub)
+    {
+      char *expire_time = fields[6];
+
+      if (strlen (expire_time) == 0)
+	expire_time = NULL;
+      else
+	{
+	  char *expire_time_orig = expire_time;
+	  struct tm tm;
+	  time_t t;
+	  char *end;
+
+	  memset (&tm, 0, sizeof (tm));
+
+	  /* parse_timestamp handles both seconds fromt he epoch and
+	     ISO 8601 format.  We also need to handle YYYY-MM-DD
+	     format (as generated by gpg1 --with-colons --list-key).
+	     Check that first and then if it fails, then try
+	     parse_timestamp.  */
+
+	  if (strptime (expire_time, "%Y-%m-%d", &tm))
+	    expire_time = tm2ldaptime (&tm);
+	  else if ((t = parse_timestamp (expire_time, &end)) != (time_t) -1
+		   && *end == '\0')
+	    {
+	      if (! gmtime_r (&t, &tm))
+		expire_time = NULL;
+	      else
+		expire_time = tm2ldaptime (&tm);
+	    }
+	  else
+	    expire_time = NULL;
+
+	  if (! expire_time)
+	    /* Failed to parse string.  */
+	    log_error ("Failed to parse creation time ('%s')",
+		       expire_time_orig);
+	}
+
+      if (expire_time)
+	{
+	  modlist_add (modlist, "pgpKeyExpireTime", expire_time);
+	  xfree (expire_time);
+	}
+    }
+
+  if ((is_uid || is_pub) && field_count >= 10)
+    {
+      char *uid = fields[9];
+
+      if (is_pub && strlen (uid) == 0)
+	/* When using gpg --list-keys, the uid is included.  When
+	   passed via gpg, it is not.  It is important to process it
+	   when it is present, because gpg 1 won't print a UID record
+	   if there is only one key.  */
+	;
+      else
+	{
+	  uncescape (uid);
+	  modlist_add (modlist, "pgpUserID", uid);
+	}
+    }
+
+ out:
+  free (fields);
+}
+
+/* Send the key in {KEY,KEYLEN} with the metadata {INFO,INFOLEN} to
+   the keyserver identified by URI.  See server.c:cmd_ks_put for the
+   format of the data and metadata.  */
+gpg_error_t
+ks_ldap_put (ctrl_t ctrl, parsed_uri_t uri,
+	     void *data, size_t datalen,
+	     void *info, size_t infolen)
+{
+  gpg_error_t err = 0;
+  int ldap_err;
+
+  LDAP *ldap_conn = NULL;
+  char *basedn = NULL;
+  char *pgpkeyattr = NULL;
+  int real_ldap;
+
+  LDAPMod **modlist = NULL;
+  LDAPMod **addlist = NULL;
+
+  char *data_armored = NULL;
+
+  /* The last byte of the info block.  */
+  const char *infoend = (const char *) info + infolen - 1;
+
+  /* Enable this code to dump the modlist to /tmp/modlist.txt.  */
+#if 0
+# warning Disable debug code before checking in.
+  const int dump_modlist = 1;
+#else
+  const int dump_modlist = 0;
+#endif
+  estream_t dump = NULL;
+
+  /* Elide a warning.  */
+  (void) ctrl;
+
+  ldap_err = ldap_connect (uri, &ldap_conn, &basedn, &pgpkeyattr, &real_ldap);
+  if (ldap_err || !basedn)
+    {
+      if (ldap_err)
+	err = ldap_err_to_gpg_err (ldap_err);
+      else
+	err = GPG_ERR_GENERAL;
+      goto out;
+    }
+
+  if (! real_ldap)
+    /* We appear to have an OpenPGP Keyserver, which can unpack the key
+       on its own (not just a dumb LDAP server).  */
+    {
+      LDAPMod mod, *attrs[2];
+      char *key[] = { data, NULL };
+      char *dn;
+
+      memset (&mod, 0, sizeof (mod));
+      mod.mod_op = LDAP_MOD_ADD;
+      mod.mod_type = pgpkeyattr;
+      mod.mod_values = key;
+      attrs[0] = &mod;
+      attrs[1] = NULL;
+
+      dn = xasprintf ("pgpCertid=virtual,%s", basedn);
+      ldap_err = ldap_add_s (ldap_conn, dn, attrs);
+      xfree (dn);
+
+      if (ldap_err != LDAP_SUCCESS)
+	{
+	  err = ldap_err_to_gpg_err (err);
+	  goto out;
+	}
+
+      goto out;
+    }
+
+  modlist = xmalloc (sizeof (LDAPMod *));
+  *modlist = NULL;
+
+  if (dump_modlist)
+    {
+      dump = es_fopen("/tmp/modlist.txt", "w");
+      if (! dump)
+	log_error ("Failed to open /tmp/modlist.txt: %s\n",
+		   strerror (errno));
+
+      if (dump)
+	{
+	  es_fprintf(dump, "data (%zd bytes)\n", datalen);
+	  es_fprintf(dump, "info (%zd bytes): '\n", infolen);
+	  es_fwrite(info, infolen, 1, dump);
+	  es_fprintf(dump, "'\n");
+	}
+    }
+
+  /* Start by nulling out all attributes.  We try and do a modify
+     operation first, so this ensures that we don't leave old
+     attributes lying around. */
+  modlist_add (&modlist, "pgpDisabled", NULL);
+  modlist_add (&modlist, "pgpKeyID", NULL);
+  modlist_add (&modlist, "pgpKeyType", NULL);
+  modlist_add (&modlist, "pgpUserID", NULL);
+  modlist_add (&modlist, "pgpKeyCreateTime", NULL);
+  modlist_add (&modlist, "pgpSignerID", NULL);
+  modlist_add (&modlist, "pgpRevoked", NULL);
+  modlist_add (&modlist, "pgpSubKeyID", NULL);
+  modlist_add (&modlist, "pgpKeySize", NULL);
+  modlist_add (&modlist, "pgpKeyExpireTime", NULL);
+  modlist_add (&modlist, "pgpCertID", NULL);
+
+  /* Assemble the INFO stuff into LDAP attributes */
+
+  while (infolen > 0)
+    {
+      char *temp = NULL;
+
+      char *newline = memchr (info, '\n', infolen);
+      if (! newline)
+	/* The last line is not \n terminated!  Make a copy so we can
+	   add a NUL terminator.  */
+	{
+	  temp = alloca (infolen + 1);
+	  memcpy (temp, info, infolen);
+	  info = temp;
+	  newline = (char *) info + infolen;
+	}
+
+      *newline = '\0';
+
+      extract_attributes (&modlist, info);
+
+      infolen = infolen - ((uintptr_t) newline - (uintptr_t) info + 1);
+      info = newline + 1;
+
+      /* Sanity check.  */
+      if (! temp)
+	assert ((char *) info + infolen - 1 == infoend);
+      else
+	assert (infolen == -1);
+    }
+
+  modlist_add (&addlist, "objectClass", "pgpKeyInfo");
+
+  err = armor_data (&data_armored, data, datalen);
+  if (err)
+    goto out;
+
+  modlist_add (&addlist, pgpkeyattr, data_armored);
+
+  /* Now append addlist onto modlist.  */
+  modlists_join (&modlist, addlist);
+
+  if (dump)
+    {
+      estream_t input = modlist_dump (modlist, NULL);
+      copy_stream (input, dump);
+      es_fclose (input);
+    }
+
+  /* Going on the assumption that modify operations are more frequent
+     than adds, we try a modify first.  If it's not there, we just
+     turn around and send an add command for the same key.  Otherwise,
+     the modify brings the server copy into compliance with our copy.
+     Note that unlike the LDAP keyserver (and really, any other
+     keyserver) this does NOT merge signatures, but replaces the whole
+     key.  This should make some people very happy. */
+  {
+    char **certid;
+    char *dn;
+
+    certid = modlist_lookup (modlist, "pgpCertID");
+    if (/* We should have a value.  */
+	! certid
+	/* Exactly one.  */
+	|| !(certid[0] && !certid[1]))
+      {
+	log_error ("Bad certid.\n");
+	err = GPG_ERR_GENERAL;
+	goto out;
+      }
+
+    dn = xasprintf ("pgpCertID=%s,%s", certid[0], basedn);
+
+    err = ldap_modify_s (ldap_conn, dn, modlist);
+    if (err == LDAP_NO_SUCH_OBJECT)
+      err = ldap_add_s (ldap_conn, dn, addlist);
+
+    xfree (dn);
+
+    if (err != LDAP_SUCCESS)
+      {
+	log_error ("gpgkeys: error adding key to keyserver: %s\n",
+		   ldap_err2string (err));
+	err = ldap_err_to_gpg_err (err);
+      }
+  }
+
+ out:
+  if (dump)
+    es_fclose (dump);
+
+  if (ldap_conn)
+    ldap_unbind (ldap_conn);
+
+  xfree (basedn);
+  xfree (pgpkeyattr);
+
+  modlist_free (modlist);
+  xfree (addlist);
+
+  xfree (data_armored);
+
+  return err;
+}