Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

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

1 files changed, 1108 insertions, 0 deletions

diff --git a/third_party/heimdal/lib/krb5/rd_req.c b/third_party/heimdal/lib/krb5/rd_req.c
new file mode 100644
index 0000000..371037c
--- /dev/null
+++ b/third_party/heimdal/lib/krb5/rd_req.c
@@ -0,0 +1,1108 @@
+
+/*
+ * Copyright (c) 1997 - 2007 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "krb5_locl.h"
+
+static krb5_error_code
+decrypt_tkt_enc_part (krb5_context context,
+		      krb5_keyblock *key,
+		      EncryptedData *enc_part,
+		      EncTicketPart *decr_part)
+{
+    krb5_error_code ret;
+    krb5_data plain;
+    size_t len;
+    krb5_crypto crypto;
+
+    ret = krb5_crypto_init(context, key, 0, &crypto);
+    if (ret)
+	return ret;
+    ret = krb5_decrypt_EncryptedData (context,
+				      crypto,
+				      KRB5_KU_TICKET,
+				      enc_part,
+				      &plain);
+    krb5_crypto_destroy(context, crypto);
+    if (ret)
+	return ret;
+
+    ret = decode_EncTicketPart(plain.data, plain.length, decr_part, &len);
+    if (ret)
+        krb5_set_error_message(context, ret,
+			       N_("Failed to decode encrypted "
+				  "ticket part", ""));
+    krb5_data_free (&plain);
+    return ret;
+}
+
+static krb5_error_code
+decrypt_authenticator (krb5_context context,
+		       EncryptionKey *key,
+		       EncryptedData *enc_part,
+		       Authenticator *authenticator,
+		       krb5_key_usage usage)
+{
+    krb5_error_code ret;
+    krb5_data plain;
+    size_t len;
+    krb5_crypto crypto;
+
+    ret = krb5_crypto_init(context, key, 0, &crypto);
+    if (ret)
+	return ret;
+    ret = krb5_decrypt_EncryptedData (context,
+				      crypto,
+				      usage /* KRB5_KU_AP_REQ_AUTH */,
+				      enc_part,
+				      &plain);
+    /* for backwards compatibility, also try the old usage */
+    if (ret && usage == KRB5_KU_TGS_REQ_AUTH)
+	ret = krb5_decrypt_EncryptedData (context,
+					  crypto,
+					  KRB5_KU_AP_REQ_AUTH,
+					  enc_part,
+					  &plain);
+    krb5_crypto_destroy(context, crypto);
+    if (ret)
+	return ret;
+
+    ret = decode_Authenticator(plain.data, plain.length,
+			       authenticator, &len);
+    krb5_data_free (&plain);
+    return ret;
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_decode_ap_req(krb5_context context,
+		   const krb5_data *inbuf,
+		   krb5_ap_req *ap_req)
+{
+    krb5_error_code ret;
+    size_t len;
+    ret = decode_AP_REQ(inbuf->data, inbuf->length, ap_req, &len);
+    if (ret)
+	return ret;
+    if (ap_req->pvno != 5){
+	free_AP_REQ(ap_req);
+	krb5_clear_error_message (context);
+	return KRB5KRB_AP_ERR_BADVERSION;
+    }
+    if (ap_req->msg_type != krb_ap_req){
+	free_AP_REQ(ap_req);
+	krb5_clear_error_message (context);
+	return KRB5KRB_AP_ERR_MSG_TYPE;
+    }
+    if (ap_req->ticket.tkt_vno != 5){
+	free_AP_REQ(ap_req);
+	krb5_clear_error_message (context);
+	return KRB5KRB_AP_ERR_BADVERSION;
+    }
+    return 0;
+}
+
+static krb5_error_code
+check_transited(krb5_context context, Ticket *ticket, EncTicketPart *enc)
+{
+    char **realms;
+    unsigned int num_realms, n;
+    krb5_error_code ret;
+
+    /*
+     * Windows 2000 and 2003 uses this inside their TGT so it's normaly
+     * not seen by others, however, samba4 joined with a Windows AD as
+     * a Domain Controller gets exposed to this.
+     */
+    if(enc->transited.tr_type == 0 && enc->transited.contents.length == 0)
+	return 0;
+
+    if(enc->transited.tr_type != domain_X500_Compress)
+	return KRB5KDC_ERR_TRTYPE_NOSUPP;
+
+    if(enc->transited.contents.length == 0)
+	return 0;
+
+    ret = krb5_domain_x500_decode(context, enc->transited.contents,
+				  &realms, &num_realms,
+				  enc->crealm,
+				  ticket->realm);
+    if(ret)
+	return ret;
+    ret = krb5_check_transited(context, enc->crealm,
+			       ticket->realm,
+			       realms, num_realms, NULL);
+    for (n = 0; n < num_realms; n++)
+	free(realms[n]);
+    free(realms);
+    return ret;
+}
+
+static krb5_error_code
+find_etypelist(krb5_context context,
+	       krb5_auth_context auth_context,
+	       EtypeList *etypes)
+{
+    krb5_error_code ret;
+    krb5_data data;
+  
+    ret = _krb5_get_ad(context, auth_context->authenticator->authorization_data, NULL, KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION, &data);
+    if (ret)
+  	return 0;
+    
+    ret = decode_EtypeList(data.data, data.length, etypes, NULL);
+    krb5_data_free(&data);
+    if (ret)
+  	krb5_clear_error_message(context);
+    
+    return ret;
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_decrypt_ticket(krb5_context context,
+		    Ticket *ticket,
+		    krb5_keyblock *key,
+		    EncTicketPart *out,
+		    krb5_flags flags)
+{
+    EncTicketPart t;
+    krb5_error_code ret;
+    ret = decrypt_tkt_enc_part (context, key, &ticket->enc_part, &t);
+    if (ret)
+	return ret;
+
+    {
+	krb5_timestamp now;
+	time_t start = t.authtime;
+
+	krb5_timeofday (context, &now);
+	if(t.starttime)
+	    start = *t.starttime;
+	if(start - now > context->max_skew
+	   || (t.flags.invalid
+	       && !(flags & KRB5_VERIFY_AP_REQ_IGNORE_INVALID))) {
+	    free_EncTicketPart(&t);
+	    krb5_clear_error_message (context);
+	    return KRB5KRB_AP_ERR_TKT_NYV;
+	}
+	if(now - t.endtime > context->max_skew) {
+	    free_EncTicketPart(&t);
+	    krb5_clear_error_message (context);
+	    return KRB5KRB_AP_ERR_TKT_EXPIRED;
+	}
+
+	if(!t.flags.transited_policy_checked) {
+	    ret = check_transited(context, ticket, &t);
+	    if(ret) {
+		free_EncTicketPart(&t);
+		return ret;
+	    }
+	}
+    }
+
+    if(out)
+	*out = t;
+    else
+	free_EncTicketPart(&t);
+    return 0;
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_verify_authenticator_checksum(krb5_context context,
+				   krb5_auth_context ac,
+				   void *data,
+				   size_t len)
+{
+    krb5_error_code ret;
+    krb5_keyblock *key = NULL;
+    krb5_authenticator authenticator;
+    krb5_crypto crypto;
+
+    ret = krb5_auth_con_getauthenticator(context, ac, &authenticator);
+    if (ret)
+	return ret;
+    if (authenticator->cksum == NULL) {
+	ret = -17;
+        goto out;
+    }
+    ret = krb5_auth_con_getkey(context, ac, &key);
+    if (ret)
+        goto out;
+    ret = krb5_crypto_init(context, key, 0, &crypto);
+    if (ret)
+	goto out;
+
+    _krb5_crypto_set_flags(context, crypto, KRB5_CRYPTO_FLAG_ALLOW_UNKEYED_CHECKSUM);
+    ret = krb5_verify_checksum(context, crypto,
+                               KRB5_KU_AP_REQ_AUTH_CKSUM,
+                               data, len, authenticator->cksum);
+    krb5_crypto_destroy(context, crypto);
+out:
+    krb5_free_authenticator(context, &authenticator);
+    krb5_free_keyblock(context, key);
+    return ret;
+}
+
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_verify_ap_req(krb5_context context,
+		   krb5_auth_context *auth_context,
+		   krb5_ap_req *ap_req,
+		   krb5_const_principal server,
+		   krb5_keyblock *keyblock,
+		   krb5_flags flags,
+		   krb5_flags *ap_req_options,
+		   krb5_ticket **ticket)
+{
+    return krb5_verify_ap_req2 (context,
+				auth_context,
+				ap_req,
+				server,
+				keyblock,
+				flags,
+				ap_req_options,
+				ticket,
+				KRB5_KU_AP_REQ_AUTH);
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_verify_ap_req2(krb5_context context,
+		    krb5_auth_context *auth_context,
+		    krb5_ap_req *ap_req,
+		    krb5_const_principal server,
+		    krb5_keyblock *keyblock,
+		    krb5_flags flags,
+		    krb5_flags *ap_req_options,
+		    krb5_ticket **ticket,
+		    krb5_key_usage usage)
+{
+    krb5_ticket *t;
+    krb5_auth_context ac;
+    krb5_error_code ret;
+    EtypeList etypes;
+    int badaddr = 0;
+
+    memset(&etypes, 0, sizeof(etypes));
+
+    if (ticket)
+	*ticket = NULL;
+
+    if (auth_context && *auth_context) {
+	ac = *auth_context;
+    } else {
+	ret = krb5_auth_con_init (context, &ac);
+	if (ret)
+	    return ret;
+    }
+
+    t = calloc(1, sizeof(*t));
+    if (t == NULL) {
+	ret = krb5_enomem(context);
+	goto out;
+    }
+
+    if (ap_req->ap_options.use_session_key && ac->keyblock){
+	ret = krb5_decrypt_ticket(context, &ap_req->ticket,
+				  ac->keyblock,
+				  &t->ticket,
+				  flags);
+	krb5_free_keyblock(context, ac->keyblock);
+	ac->keyblock = NULL;
+    }else
+	ret = krb5_decrypt_ticket(context, &ap_req->ticket,
+				  keyblock,
+				  &t->ticket,
+				  flags);
+
+    if(ret)
+	goto out;
+
+    ret = _krb5_principalname2krb5_principal(context,
+					     &t->server,
+					     ap_req->ticket.sname,
+					     ap_req->ticket.realm);
+    if (ret) goto out;
+
+    ret = decrypt_authenticator (context,
+				 &t->ticket.key,
+				 &ap_req->authenticator,
+				 ac->authenticator,
+				 usage);
+    if (ret)
+	goto out;
+
+    {
+	krb5_principal p1, p2;
+	krb5_boolean res;
+
+	_krb5_principalname2krb5_principal(context,
+					   &p1,
+					   ac->authenticator->cname,
+					   ac->authenticator->crealm);
+	_krb5_principalname2krb5_principal(context,
+					   &p2,
+					   t->ticket.cname,
+					   t->ticket.crealm);
+	res = krb5_principal_compare (context, p1, p2);
+	krb5_free_principal (context, p1);
+	krb5_free_principal (context, p2);
+	if (!res) {
+	    ret = KRB5KRB_AP_ERR_BADMATCH;
+	    krb5_clear_error_message (context);
+	    goto out;
+	}
+    }
+
+    /*
+     * The ticket authenticates the client, and conveys naming attributes that
+     * we want to expose in GSS using RFC6680 APIs.
+     *
+     * So we same the ticket enc-part in the client's krb5_principal object
+     * (note though that the session key will be absent in that copy of the
+     * ticket enc-part).
+     */
+    ret = _krb5_ticket2krb5_principal(context, &t->client, &t->ticket,
+                                      ac->authenticator->authorization_data);
+    if (ret) goto out;
+
+    t->client->nameattrs->peer_realm =
+        calloc(1, sizeof(t->client->nameattrs->peer_realm[0]));
+    if (t->client->nameattrs->peer_realm == NULL) {
+        ret = krb5_enomem(context);
+        goto out;
+    }
+    ret = copy_Realm(&ap_req->ticket.realm, t->client->nameattrs->peer_realm);
+    if (ret) goto out;
+
+    /* check addresses */
+
+    if (t->ticket.caddr
+	&& ac->remote_address
+	&& !krb5_address_search (context,
+				 ac->remote_address,
+				 t->ticket.caddr)) {
+        /*
+         * Hack alert.  If KRB5_VERIFY_AP_REQ_IGNORE_ADDRS and the client's
+         * address didn't check out then we'll return KRB5KRB_AP_ERR_BADADDR
+         * even on success, and we'll let the caller figure it out because
+         * `*ticket != NULL' or `*auth_context != NULL'.
+         */
+        if ((flags & KRB5_VERIFY_AP_REQ_IGNORE_ADDRS)) {
+            badaddr = 1;
+        } else {
+            ret = KRB5KRB_AP_ERR_BADADDR;
+            krb5_clear_error_message(context);
+            goto out;
+        }
+    }
+
+    /* check timestamp in authenticator */
+    {
+	krb5_timestamp now;
+
+	krb5_timeofday (context, &now);
+
+	if (krb5_time_abs(ac->authenticator->ctime, now) > context->max_skew) {
+	    ret = KRB5KRB_AP_ERR_SKEW;
+	    krb5_clear_error_message (context);
+	    goto out;
+	}
+    }
+
+    if (ac->authenticator->seq_number)
+	krb5_auth_con_setremoteseqnumber(context, ac,
+					 *ac->authenticator->seq_number);
+
+    /* XXX - Xor sequence numbers */
+
+    if (ac->authenticator->subkey) {
+	ret = krb5_auth_con_setremotesubkey(context, ac,
+					    ac->authenticator->subkey);
+	if (ret)
+	    goto out;
+    }
+
+    ret = find_etypelist(context, ac, &etypes);
+    if (ret)
+	goto out;
+
+    ac->keytype = ETYPE_NULL;
+
+    if (etypes.val) {
+	size_t i;
+
+	for (i = 0; i < etypes.len; i++) {
+	    if (krb5_enctype_valid(context, etypes.val[i]) == 0) {
+		ac->keytype = etypes.val[i];
+		break;
+	    }
+	}
+    }
+
+    /* save key */
+    ret = krb5_copy_keyblock(context, &t->ticket.key, &ac->keyblock);
+    if (ret) goto out;
+
+    if (ap_req_options) {
+	*ap_req_options = 0;
+	if (ac->keytype != ETYPE_NULL)
+	    *ap_req_options |= AP_OPTS_USE_SUBKEY;
+	if (ap_req->ap_options.use_session_key)
+	    *ap_req_options |= AP_OPTS_USE_SESSION_KEY;
+	if (ap_req->ap_options.mutual_required)
+	    *ap_req_options |= AP_OPTS_MUTUAL_REQUIRED;
+    }
+
+    if(ticket)
+	*ticket = t;
+    else
+	krb5_free_ticket (context, t);
+    if (auth_context) {
+	if (*auth_context == NULL)
+	    *auth_context = ac;
+    } else
+	krb5_auth_con_free (context, ac);
+    free_EtypeList(&etypes);
+
+    if (badaddr) {
+        krb5_clear_error_message(context);
+        return KRB5KRB_AP_ERR_BADADDR;
+    }
+    return 0;
+ out:
+    free_EtypeList(&etypes);
+    if (t)
+	krb5_free_ticket (context, t);
+    if (auth_context == NULL || *auth_context == NULL)
+	krb5_auth_con_free (context, ac);
+    return ret;
+}
+
+/*
+ *
+ */
+
+struct krb5_rd_req_in_ctx_data {
+    krb5_keytab keytab;
+    krb5_keyblock *keyblock;
+    krb5_boolean check_pac;
+};
+
+struct krb5_rd_req_out_ctx_data {
+    krb5_keyblock *keyblock;
+    krb5_flags ap_req_options;
+    krb5_ticket *ticket;
+    krb5_principal server;
+};
+
+/**
+ * Allocate a krb5_rd_req_in_ctx as an input parameter to
+ * krb5_rd_req_ctx(). The caller should free the context with
+ * krb5_rd_req_in_ctx_free() when done with the context.
+ *
+ * @param context Keberos 5 context.
+ * @param ctx in ctx to krb5_rd_req_ctx().
+ *
+ * @return Kerberos 5 error code, see krb5_get_error_message().
+ *
+ * @ingroup krb5_auth
+ */
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req_in_ctx_alloc(krb5_context context, krb5_rd_req_in_ctx *ctx)
+{
+    *ctx = calloc(1, sizeof(**ctx));
+    if (*ctx == NULL)
+	return krb5_enomem(context);
+    (*ctx)->check_pac = (context->flags & KRB5_CTX_F_CHECK_PAC) ? 1 : 0;
+    return 0;
+}
+
+/**
+ * Set the keytab that krb5_rd_req_ctx() will use.
+ *
+ * @param context Keberos 5 context.
+ * @param in in ctx to krb5_rd_req_ctx().
+ * @param keytab keytab that krb5_rd_req_ctx() will use, only copy the
+ *        pointer, so the caller must free they keytab after
+ *        krb5_rd_req_in_ctx_free() is called.
+ *
+ * @return Kerberos 5 error code, see krb5_get_error_message().
+ *
+ * @ingroup krb5_auth
+ */
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req_in_set_keytab(krb5_context context,
+			  krb5_rd_req_in_ctx in,
+			  krb5_keytab keytab)
+{
+    in->keytab = keytab;
+    return 0;
+}
+
+/**
+ * Set if krb5_rq_red() is going to check the Windows PAC or not
+ *
+ * @param context Keberos 5 context.
+ * @param in krb5_rd_req_in_ctx to check the option on.
+ * @param flag flag to select if to check the pac (TRUE) or not (FALSE).
+ *
+ * @return Kerberos 5 error code, see krb5_get_error_message().
+ *
+ * @ingroup krb5_auth
+ */
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req_in_set_pac_check(krb5_context context,
+			     krb5_rd_req_in_ctx in,
+			     krb5_boolean flag)
+{
+    in->check_pac = flag;
+    return 0;
+}
+
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req_in_set_keyblock(krb5_context context,
+			    krb5_rd_req_in_ctx in,
+			    krb5_keyblock *keyblock)
+{
+    in->keyblock = keyblock; /* XXX should make copy */
+    return 0;
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req_out_get_ap_req_options(krb5_context context,
+				   krb5_rd_req_out_ctx out,
+				   krb5_flags *ap_req_options)
+{
+    *ap_req_options = out->ap_req_options;
+    return 0;
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req_out_get_ticket(krb5_context context,
+			    krb5_rd_req_out_ctx out,
+			    krb5_ticket **ticket)
+{
+    return krb5_copy_ticket(context, out->ticket, ticket);
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req_out_get_keyblock(krb5_context context,
+			    krb5_rd_req_out_ctx out,
+			    krb5_keyblock **keyblock)
+{
+    return krb5_copy_keyblock(context, out->keyblock, keyblock);
+}
+
+/**
+ * Get the principal that was used in the request from the
+ * client. Might not match whats in the ticket if krb5_rd_req_ctx()
+ * searched in the keytab for a matching key.
+ *
+ * @param context a Kerberos 5 context.
+ * @param out a krb5_rd_req_out_ctx from krb5_rd_req_ctx().
+ * @param principal return principal, free with krb5_free_principal().
+ *
+ * @ingroup krb5_auth
+ */
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req_out_get_server(krb5_context context,
+			    krb5_rd_req_out_ctx out,
+			    krb5_principal *principal)
+{
+    return krb5_copy_principal(context, out->server, principal);
+}
+
+KRB5_LIB_FUNCTION void KRB5_LIB_CALL
+krb5_rd_req_in_ctx_free(krb5_context context, krb5_rd_req_in_ctx ctx)
+{
+    free(ctx);
+}
+
+/**
+ * Free the krb5_rd_req_out_ctx.
+ *
+ * @param context Keberos 5 context.
+ * @param ctx krb5_rd_req_out_ctx context to free.
+ *
+ * @ingroup krb5_auth
+ */
+
+KRB5_LIB_FUNCTION void KRB5_LIB_CALL
+krb5_rd_req_out_ctx_free(krb5_context context, krb5_rd_req_out_ctx ctx)
+{
+    if (ctx->ticket)
+	krb5_free_ticket(context, ctx->ticket);
+    if (ctx->keyblock)
+	krb5_free_keyblock(context, ctx->keyblock);
+    if (ctx->server)
+	krb5_free_principal(context, ctx->server);
+    free(ctx);
+}
+
+/**
+ * Process an AP_REQ message.
+ *
+ * @param context        Kerberos 5 context.
+ * @param auth_context   authentication context of the peer.
+ * @param inbuf          the AP_REQ message, obtained for example with krb5_read_message().
+ * @param server         server principal.
+ * @param keytab         server keytab.
+ * @param ap_req_options set to the AP_REQ options. See the AP_OPTS_* defines.
+ * @param ticket         on success, set to the authenticated client credentials.
+ *                       Must be deallocated with krb5_free_ticket(). If not
+ *                       interested, pass a NULL value.
+ *
+ * @return 0 to indicate success. Otherwise a Kerberos error code is
+ *         returned, see krb5_get_error_message().
+ */
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req(krb5_context context,
+	    krb5_auth_context *auth_context,
+	    const krb5_data *inbuf,
+	    krb5_const_principal server,
+	    krb5_keytab keytab,
+	    krb5_flags *ap_req_options,
+	    krb5_ticket **ticket)
+{
+    krb5_error_code ret;
+    krb5_rd_req_in_ctx in;
+    krb5_rd_req_out_ctx out;
+
+    ret = krb5_rd_req_in_ctx_alloc(context, &in);
+    if (ret)
+	return ret;
+
+    ret = krb5_rd_req_in_set_keytab(context, in, keytab);
+    if (ret) {
+	krb5_rd_req_in_ctx_free(context, in);
+	return ret;
+    }
+
+    ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
+    krb5_rd_req_in_ctx_free(context, in);
+    if (ret)
+	return ret;
+
+    if (ap_req_options)
+	*ap_req_options = out->ap_req_options;
+    if (ticket) {
+	ret = krb5_copy_ticket(context, out->ticket, ticket);
+	if (ret)
+	    goto out;
+    }
+
+out:
+    krb5_rd_req_out_ctx_free(context, out);
+    return ret;
+}
+
+/*
+ *
+ */
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req_with_keyblock(krb5_context context,
+			  krb5_auth_context *auth_context,
+			  const krb5_data *inbuf,
+			  krb5_const_principal server,
+			  krb5_keyblock *keyblock,
+			  krb5_flags *ap_req_options,
+			  krb5_ticket **ticket)
+{
+    krb5_error_code ret;
+    krb5_rd_req_in_ctx in;
+    krb5_rd_req_out_ctx out;
+
+    ret = krb5_rd_req_in_ctx_alloc(context, &in);
+    if (ret)
+	return ret;
+
+    ret = krb5_rd_req_in_set_keyblock(context, in, keyblock);
+    if (ret) {
+	krb5_rd_req_in_ctx_free(context, in);
+	return ret;
+    }
+
+    ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out);
+    krb5_rd_req_in_ctx_free(context, in);
+    if (ret)
+	return ret;
+
+    if (ap_req_options)
+	*ap_req_options = out->ap_req_options;
+    if (ticket) {
+	ret = krb5_copy_ticket(context, out->ticket, ticket);
+	if (ret)
+	    goto out;
+    }
+
+out:
+    krb5_rd_req_out_ctx_free(context, out);
+    return ret;
+}
+
+/*
+ *
+ */
+
+static krb5_error_code
+get_key_from_keytab(krb5_context context,
+		    krb5_ap_req *ap_req,
+		    krb5_const_principal server,
+		    krb5_keytab keytab,
+		    krb5_keyblock **out_key)
+{
+    krb5_keytab_entry entry;
+    krb5_error_code ret;
+    int kvno;
+    krb5_keytab real_keytab;
+
+    if(keytab == NULL)
+	krb5_kt_default(context, &real_keytab);
+    else
+	real_keytab = keytab;
+
+    if (ap_req->ticket.enc_part.kvno)
+	kvno = *ap_req->ticket.enc_part.kvno;
+    else
+	kvno = 0;
+
+    ret = krb5_kt_get_entry (context,
+			     real_keytab,
+			     server,
+			     kvno,
+			     ap_req->ticket.enc_part.etype,
+			     &entry);
+    if(ret == 0) {
+        ret = krb5_copy_keyblock(context, &entry.keyblock, out_key);
+        krb5_kt_free_entry(context, &entry);
+    }
+    if(keytab == NULL)
+	krb5_kt_close(context, real_keytab);
+
+    return ret;
+}
+
+/**
+ * The core server function that verify application authentication
+ * requests from clients.
+ *
+ * @param context Keberos 5 context.
+ * @param auth_context the authentication context, can be NULL, then
+ *        default values for the authentication context will used.
+ * @param inbuf the (AP-REQ) authentication buffer
+ *
+ * @param server the server to authenticate to. If NULL the function
+ *        will try to find any available credential in the keytab
+ *        that will verify the reply. The function will prefer the
+ *        server specified in the AP-REQ, but if
+ *        there is no mach, it will try all keytab entries for a
+ *        match. This has serious performance issues for large keytabs.
+ *
+ * @param inctx control the behavior of the function, if NULL, the
+ *        default behavior is used.
+ * @param outctx the return outctx, free with krb5_rd_req_out_ctx_free().
+ * @return Kerberos 5 error code, see krb5_get_error_message().
+ *
+ * @ingroup krb5_auth
+ */
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_rd_req_ctx(krb5_context context,
+		krb5_auth_context *auth_context,
+		const krb5_data *inbuf,
+		krb5_const_principal server,
+		krb5_rd_req_in_ctx inctx,
+		krb5_rd_req_out_ctx *outctx)
+{
+    krb5_error_code ret;
+    krb5_ap_req ap_req;
+    krb5_rd_req_out_ctx o = NULL;
+    krb5_keytab id = NULL, keytab = NULL;
+    krb5_principal service = NULL;
+
+    if (outctx)
+        *outctx = NULL;
+
+    o = calloc(1, sizeof(*o));
+    if (o == NULL)
+	return krb5_enomem(context);
+
+    if (*auth_context == NULL) {
+	ret = krb5_auth_con_init(context, auth_context);
+	if (ret)
+	    goto out;
+    }
+
+    ret = krb5_decode_ap_req(context, inbuf, &ap_req);
+    if(ret)
+	goto out;
+
+    /* Save the principal that was in the request */
+    ret = _krb5_principalname2krb5_principal(context,
+					     &o->server,
+					     ap_req.ticket.sname,
+					     ap_req.ticket.realm);
+    if (ret)
+	goto out;
+
+    if (ap_req.ap_options.use_session_key &&
+	(*auth_context)->keyblock == NULL) {
+	ret = KRB5KRB_AP_ERR_NOKEY;
+	krb5_set_error_message(context, ret,
+			       N_("krb5_rd_req: user to user auth "
+				  "without session key given", ""));
+	goto out;
+    }
+
+    if (inctx && inctx->keytab)
+	id = inctx->keytab;
+
+    if((*auth_context)->keyblock){
+	ret = krb5_copy_keyblock(context,
+				 (*auth_context)->keyblock,
+				 &o->keyblock);
+	if (ret)
+	    goto out;
+    } else if(inctx && inctx->keyblock){
+	ret = krb5_copy_keyblock(context,
+				 inctx->keyblock,
+				 &o->keyblock);
+	if (ret)
+	    goto out;
+    } else {
+
+	if(id == NULL) {
+	    krb5_kt_default(context, &keytab);
+	    id = keytab;
+	}
+	if (id == NULL)
+	    goto out;
+
+	if (server == NULL) {
+	    ret = _krb5_principalname2krb5_principal(context,
+						     &service,
+						     ap_req.ticket.sname,
+						     ap_req.ticket.realm);
+	    if (ret)
+		goto out;
+	    server = service;
+	}
+
+	ret = get_key_from_keytab(context,
+				  &ap_req,
+				  server,
+				  id,
+				  &o->keyblock);
+	if (ret) {
+	    /* If caller specified a server, fail. */
+	    if (service == NULL && (context->flags & KRB5_CTX_F_RD_REQ_IGNORE) == 0)
+		goto out;
+	    /* Otherwise, fall back to iterating over the keytab. This
+	     * have serious performace issues for larger keytab.
+	     */
+	    o->keyblock = NULL;
+	}
+    }
+
+    if (o->keyblock) {
+	/*
+	 * We got an exact keymatch, use that.
+	 */
+
+	ret = krb5_verify_ap_req2(context,
+				  auth_context,
+				  &ap_req,
+				  server,
+				  o->keyblock,
+				  0,
+				  &o->ap_req_options,
+				  &o->ticket,
+				  KRB5_KU_AP_REQ_AUTH);
+
+	if (ret)
+	    goto out;
+
+    } else {
+	/*
+	 * Interate over keytab to find a key that can decrypt the request.
+	 */
+
+	krb5_keytab_entry entry;
+	krb5_kt_cursor cursor;
+	int done = 0, kvno = 0;
+
+	memset(&cursor, 0, sizeof(cursor));
+
+	if (ap_req.ticket.enc_part.kvno)
+	    kvno = *ap_req.ticket.enc_part.kvno;
+
+	ret = krb5_kt_start_seq_get(context, id, &cursor);
+	if (ret)
+	    goto out;
+
+	done = 0;
+	while (!done) {
+	    krb5_principal p;
+
+	    ret = krb5_kt_next_entry(context, id, &entry, &cursor);
+	    if (ret) {
+		_krb5_kt_principal_not_found(context, ret, id, o->server,
+					     ap_req.ticket.enc_part.etype,
+					     kvno);
+		break;
+	    }
+
+	    if (entry.keyblock.keytype != ap_req.ticket.enc_part.etype) {
+		krb5_kt_free_entry (context, &entry);
+		continue;
+	    }
+
+	    ret = krb5_verify_ap_req2(context,
+				      auth_context,
+				      &ap_req,
+				      server,
+				      &entry.keyblock,
+				      0,
+				      &o->ap_req_options,
+				      &o->ticket,
+				      KRB5_KU_AP_REQ_AUTH);
+	    if (ret) {
+		krb5_kt_free_entry (context, &entry);
+		continue;
+	    }
+
+	    /*
+	     * Found a match, save the keyblock for PAC processing,
+	     * and update the service principal in the ticket to match
+	     * whatever is in the keytab.
+	     */
+
+	    ret = krb5_copy_keyblock(context,
+				     &entry.keyblock,
+				     &o->keyblock);
+	    if (ret) {
+		krb5_kt_free_entry (context, &entry);
+		break;
+	    }
+
+	    ret = krb5_copy_principal(context, entry.principal, &p);
+	    if (ret) {
+		krb5_kt_free_entry (context, &entry);
+		break;
+	    }
+	    krb5_free_principal(context, o->ticket->server);
+	    o->ticket->server = p;
+
+	    krb5_kt_free_entry (context, &entry);
+
+	    done = 1;
+	}
+	krb5_kt_end_seq_get (context, id, &cursor);
+        if (ret)
+            goto out;
+    }
+
+    ret = krb5_ticket_get_authorization_data_type(context, o->ticket,
+                                                  KRB5_AUTHDATA_KDC_ISSUED,
+                                                  NULL);
+    if (ret == 0)
+        o->ticket->client->nameattrs->kdc_issued_verified = 1;
+
+    /* If there is a PAC, verify its server signature */
+    if (inctx == NULL || inctx->check_pac) {
+	krb5_pac pac;
+	krb5_data data;
+
+	ret = krb5_ticket_get_authorization_data_type(context,
+						      o->ticket,
+						      KRB5_AUTHDATA_WIN2K_PAC,
+						      &data);
+	if (ret == 0) {
+	    ret = krb5_pac_parse(context, data.data, data.length, &pac);
+	    krb5_data_free(&data);
+	    if (ret)
+		goto out;
+
+	    ret = krb5_pac_verify(context,
+				  pac,
+				  o->ticket->ticket.authtime,
+				  o->ticket->client,
+				  o->keyblock,
+				  NULL);
+            if (ret == 0)
+                o->ticket->client->nameattrs->pac_verified = 1;
+	    if (ret == 0 && (context->flags & KRB5_CTX_F_REPORT_CANONICAL_CLIENT_NAME)) {
+		krb5_error_code ret2;
+		krb5_principal canon_name;
+
+		ret2 = _krb5_pac_get_canon_principal(context, pac, &canon_name);
+		if (ret2 == 0) {
+                    free_Realm(&o->ticket->client->realm);
+                    free_PrincipalName(&o->ticket->client->name);
+                    ret = copy_Realm(&canon_name->realm, &o->ticket->client->realm);
+                    if (ret == 0)
+                        ret = copy_PrincipalName(&canon_name->name, &o->ticket->client->name);
+                    krb5_free_principal(context, canon_name);
+		} else if (ret2 != ENOENT)
+		    ret = ret2;
+	    }
+	    if (ret) {
+		krb5_pac_free(context, pac);
+		goto out;
+	    }
+	    o->ticket->client->nameattrs->pac = pac;
+	} else
+	  ret = 0;
+    }
+out:
+
+    if (ret || outctx == NULL)
+	krb5_rd_req_out_ctx_free(context, o);
+    else
+	*outctx = o;
+
+    free_AP_REQ(&ap_req);
+
+    if (service)
+	krb5_free_principal(context, service);
+
+    if (keytab)
+	krb5_kt_close(context, keytab);
+
+    return ret;
+}