X-Git-Url: http://www.project-moonshot.org/gitweb/?a=blobdiff_plain;f=mod_auth_gssweb.c;h=9bfcca72852762c4765c0ea4af09096d198ff711;hb=a27b292813973201e7a3c2131a93644ac6a97f93;hp=f59fe728391e6e6fce17c61782b89d2e28cd893e;hpb=d3713d71def8134987b474b83db4980241516868;p=mod_auth_kerb.cvs%2F.git

diff --git a/mod_auth_gssweb.c b/mod_auth_gssweb.c
index f59fe72..9bfcca7 100644
--- a/mod_auth_gssweb.c
+++ b/mod_auth_gssweb.c
@@ -1,39 +1,42 @@
 /*
- * Copyright (c) 2010 CESNET
+ * Copyright (c) 2012, 2013, 2014 JANET(UK)
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
+ * 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.
+ * 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 CESNET nor the names of its contributors may
- *    be used to endorse or promote products derived from this software
+ * 3. Neither the name of JANET(UK) 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
- */
-
-/* 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT HOLDER 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.
+ *
+ * NOTE: Some code in this module was derived from code in
+ * mod_auth_gssapi.c which is copyrighted by CESNET.  See that file
+ * for full copyright details.
+ *
  * NOTE: Portions of the code in this file were derived from example
  * code distributed under the Apache 2.0 license:
  *     http://www.apache.org/licenses/LICENSE-2.0
- * The example code was modified for inclusion in this module.
  * 
  * This module implements the Apache server side of the GSSWeb
  * authentiction type which allows Moonshot to be used for
@@ -49,6 +52,7 @@
  * described in the protocol.txt file included with module source.
  */
 
+#include <stdio.h>
 #include "mod_auth_gssweb.h"
 
 module AP_MODULE_DECLARE_DATA auth_gssweb_module;
@@ -68,36 +72,37 @@ static const command_rec gssweb_config_cmds[] = {
 #define DEFAULT_ENCTYPE		"application/x-www-form-urlencoded"
 #define GSS_MAX_TOKEN_SIZE	4096	//TBD -- check this value
 
-/* gssweb_read_post() -- Reads the post data associated with a
- * request.
+/* gssweb_read_req() -- reads the request data into a buffer 
  */
-static int gssweb_read_post(request_rec *r, const char **rbuf)
+static int gssweb_read_req(request_rec *r, const char **rbuf, apr_off_t *size)
 {
-  int rc;
-  if ((rc = ap_setup_client_block(r, REQUEST_CHUNKED_ERROR)) != OK) {
-    return rc;
+  int rc = OK;
+
+  if((rc = ap_setup_client_block(r, REQUEST_CHUNKED_ERROR))) {
+    return(rc);
   }
-  if (ap_should_client_block(r)) {
-    char argsbuffer[GSS_MAX_TOKEN_SIZE+256];
-    int rsize, len_read, rpos = 0;
-    long length = r->remaining;
-    *rbuf = ap_pcalloc(r->pool, length + 1);
-    ap_hard_timeout("util_read", r);
-    while ((len_read =
-	    ap_get_client_block(r, argsbuffer, sizeof(argsbuffer))) > 0) { 
-      ap_reset_timeout(r);
-      if ((rpos + len_read) > length) {
+  
+  if(ap_should_client_block(r)) {
+
+    char         argsbuffer[HUGE_STRING_LEN];
+    apr_off_t    rsize, len_read, rpos = 0;
+    apr_off_t    length = r->remaining;
+
+    *rbuf = (const char *) apr_pcalloc(r->pool, (apr_size_t) (length + 1));
+    *size = length;
+    while((len_read = ap_get_client_block(r, argsbuffer, sizeof(argsbuffer))) > 0) {
+      if((rpos + len_read) > length) {
 	rsize = length - rpos;
       }
       else {
 	rsize = len_read;
       }
-      memcpy((char*)*rbuf + rpos, argsbuffer, rsize);
+      
+      memcpy((char *) *rbuf + rpos, argsbuffer, (size_t) rsize);
       rpos += rsize;
     }
-    ap_kill_timeout(r);
   }
-  return rc;
+  return(rc);
 }
 
 /* gssweb_get_post_data() -- Gets the token and nonce from the request
@@ -106,34 +111,57 @@ static int gssweb_read_post(request_rec *r, const char **rbuf)
 static int gssweb_get_post_data(request_rec *r, int *nonce, gss_buffer_desc *input_token)
 {
   const char *data;
+  apr_off_t datalen;
   const char *key, *val, *type;
   int rc = 0;
 
+  *nonce = 0;
+  input_token->length = 0;
+  input_token->value = NULL;
+
   if(r->method_number != M_POST) {
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: Request data is not a POST, declining.");
     return DECLINED;
   }
 
-  type = ap_table_get(r->headers_in, "Content-Type");
+  type = apr_table_get(r->headers_in, "Content-Type");
   if(strcasecmp(type, DEFAULT_ENCTYPE) != 0) {
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: Unexpected content type, declining.");
     return DECLINED;
   }
 
-  if((rc = util_read(r, &data)) != OK) {
+  if((rc = gssweb_read_req(r, &data, &datalen)) != OK) {
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: Data read error, rc = %d", rc);
     return rc;
   }
-  if(*tab) {
-    ap_clear_table(*tab);
-  }
-  else {
-    *tab = ap_make_table(r->pool, 8);
-  }
+
   while(*data && (val = ap_getword(r->pool, &data, '&'))) { 
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: obtained val from ap_getword() (%s)", val);
     key = ap_getword(r->pool, &val, '=');
     ap_unescape_url((char*)key);
     ap_unescape_url((char*)val);
-    ap_table_merge(*tab, key, val);
+    if (0 == strcasecmp(key, "token")) {
+      gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: found token (%s)", val);
+      input_token->value = malloc(strlen(val));
+      input_token->length = apr_base64_decode(input_token->value, val);
+      gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: Token successfully decoded.");
+    }
+    else if (0 == strcasecmp(key, "nonce")) {
+      gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: found nonce (%s)", val);
+      *nonce = atoi(val);
+    }
+    else {
+      gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: unknown key (%s)", key);
+    }
+  }
+  if ((0 == *nonce) || (0 == input_token->length)) {
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: nonce (%d) or token len (%d) is 0, declining", *nonce, input_token->length);
+    return DECLINED;
+  }
+  else {
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_get_post_data: returning nonce (%d) and token (%d bytes)", *nonce, input_token->length);
+    return OK;
   }
-  return OK;
 }
 
 /* gssweb_authenticate_filter() -- Output filter for gssweb authentication.
@@ -143,72 +171,184 @@ static int gssweb_get_post_data(request_rec *r, int *nonce, gss_buffer_desc *inp
  * one filter call by maintaining state until an EOS bucket is received.
  */
 static apr_status_t gssweb_authenticate_filter (ap_filter_t *f,
-                                        apr_bucket_brigade *pbbIn)
+                                        apr_bucket_brigade *brig_in)
 {
   request_rec *r = f->r;
   conn_rec *c = r->connection;
-  apr_bucket *pbktIn;
-  apr_bucket_brigade *pbbOut;
+  apr_bucket_brigade *brig_out;
+  apr_bucket *bkt_in = NULL;
+  apr_bucket *bkt_out = NULL;
+  apr_bucket *bkt_eos = NULL;
+  const char *data = NULL;
+  apr_size_t len = 0;
+  apr_size_t enc_len = 0;
+  char *buf = NULL;
+  char *stoken = NULL;
+  apr_size_t n = 0;
+  gss_conn_ctx conn_ctx = NULL;
+  const char *c_type = NULL;
+  const char *c_len = NULL;
+  apr_status_t ret = 0;
+
+  gss_log(APLOG_MARK, APLOG_DEBUG, 0, f->r, "Entering GSSWeb filter");
+
+  /* get the context from the request */
+  conn_ctx = gss_retrieve_conn_ctx(r);
+  if (NULL == conn_ctx) {
+    gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Failed to find valid context.");
+    apr_brigade_cleanup(brig_in);
+    return HTTP_INTERNAL_SERVER_ERROR;
+  }
+    
+  /* if this is the first call for a response, send opening JSON block */
+  if (GSS_FILT_NEW == conn_ctx->filter_stat) {
+    if (NULL == (brig_out = apr_brigade_create(r->pool, c->bucket_alloc))) {
+      conn_ctx->filter_stat = GSS_FILT_ERROR;
+      gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate output brigade (opening)");
+      apr_brigade_cleanup(brig_in);
+      return HTTP_INTERNAL_SERVER_ERROR;
+    }
 
-  pbbOut=apr_brigade_create(r->pool, c->bucket_alloc);
-  for (pbktIn = APR_BRIGADE_FIRST(pbbIn);
-       pbktIn != APR_BRIGADE_SENTINEL(pbbIn);
-       pbktIn = APR_BUCKET_NEXT(pbktIn))
+    len = apr_base64_encode_len(conn_ctx->output_token.length);
+    if (NULL == (data = apr_bucket_alloc(len+1024, c->bucket_alloc)) ||
+	NULL == (stoken = apr_bucket_alloc(len+1, c->bucket_alloc))) {
+      gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate space for opening json block");
+      apr_brigade_cleanup(brig_in);
+      apr_brigade_cleanup(brig_out);
+      return HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    apr_base64_encode_binary(stoken, conn_ctx->output_token.value, conn_ctx->output_token.length);
+    snprintf((char *)data, len+1024, 
+	     "{\"gssweb\": {\n\"token\": \"%s\",\n\"nonce\": \"%d\"},\n\"application\": {\n\"data\": \"", 
+	     stoken, conn_ctx->nonce);
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: Sending (%d bytes): %s", strlen(data), data);
+    
+    bkt_out = apr_bucket_heap_create(data, strlen(data), apr_bucket_free,
+				     c->bucket_alloc);
+    APR_BRIGADE_INSERT_TAIL(brig_out, bkt_out);
+    if (0 != (ret = ap_pass_brigade(f->next, brig_out))) {
+      apr_brigade_cleanup(brig_in);
+      apr_brigade_cleanup(brig_out);
+      return ret;
+    }
+
+    conn_ctx->filter_stat = GSS_FILT_INPROGRESS;
+  }
+
+  /* loop through the app data buckets, escaping and sending each one */
+  for (bkt_in = APR_BRIGADE_FIRST(brig_in);
+       bkt_in != APR_BRIGADE_SENTINEL(brig_in);
+       bkt_in = APR_BUCKET_NEXT(bkt_in))
     {
-      const char *data;
-      apr_size_t len;
-      char *buf;
-      apr_size_t n;
-      apr_bucket *pbktOut;
+      if (NULL == (brig_out = apr_brigade_create(r->pool, c->bucket_alloc))) {
+	    gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate brigade (loop)");
+	    conn_ctx->filter_stat = GSS_FILT_ERROR;
+	    apr_brigade_cleanup(brig_in);
+	    return HTTP_INTERNAL_SERVER_ERROR;
+      }
 
-      if(APR_BUCKET_IS_EOS(pbktIn))
+      /* if this is an EOS, send the JSON closing block */
+      if(APR_BUCKET_IS_EOS(bkt_in))
 	{
-	  apr_bucket *pbktEOS=apr_bucket_eos_create(c->bucket_alloc);
-	  APR_BRIGADE_INSERT_TAIL(pbbOut,pbktEOS);
-	  continue;
+	  /* create and add the JSON closing block */
+	  
+	  if (NULL == (data = apr_bucket_alloc(1024, c->bucket_alloc))) {
+	      gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate space for closing json block");
+	      apr_brigade_cleanup(brig_in);
+	      apr_brigade_cleanup(brig_out);
+	      return HTTP_INTERNAL_SERVER_ERROR;
+	  }
+
+	  c_type = apr_table_get(r->headers_in, "Content-Type");
+          c_len = apr_table_get(r->headers_in, "Content-Length");
+	  snprintf((char *)data, 1024, "\",\n\"content-type\": \"%s\",\n\"content-length\": \"%s\"\n}\n}", c_type, c_len);
+	  gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: Sending (%d bytes) %s", strlen(data), data);
+
+	  bkt_out = apr_bucket_heap_create(data, strlen(data), apr_bucket_free,
+					   c->bucket_alloc);
+	  APR_BRIGADE_INSERT_TAIL(brig_out, bkt_out);
+
+	  /* Indicate that the next filter call is a new response */
+	  conn_ctx->filter_stat = GSS_FILT_NEW;
+	  
+	  /* set EOS in the outbound brigade */
+	  bkt_eos = apr_bucket_eos_create(c->bucket_alloc);
+	  APR_BRIGADE_INSERT_TAIL (brig_out, bkt_eos);
+	  
+	  /* pass the brigade */
+	  gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: Sending: EOS");
+	  if (0 != (ret = ap_pass_brigade(f->next, brig_out))) {
+	    conn_ctx->filter_stat = GSS_FILT_ERROR;
+	    apr_brigade_cleanup(brig_in);
+	    apr_brigade_cleanup(brig_out);
+	    return ret;
+	  }
+	  break;
 	}
 
-      /* read */
-      apr_bucket_read(pbktIn,&data,&len,APR_BLOCK_READ);
+      /* Read application data from each input bucket */
+      apr_bucket_read(bkt_in, &data, &len, APR_BLOCK_READ);
+      gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: Application Data (%d bytes): %s", len, data);
+
+      /* Base64 encode the data */
+      enc_len = apr_base64_encode_len(len);
+      if (NULL == (buf = apr_bucket_alloc(enc_len, c->bucket_alloc))) {
+	gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_filter: Unable to allocate space for application data");
+	apr_brigade_cleanup(brig_in);
+	apr_brigade_cleanup(brig_out);
+	return HTTP_INTERNAL_SERVER_ERROR;
+      }
+      enc_len = apr_base64_encode_binary(buf, data, len);
+
+      /* Put the data in a bucket and add it to the the output brigade */
+      bkt_out = apr_bucket_heap_create(buf, enc_len-1, apr_bucket_free, c->bucket_alloc);
+      buf[enc_len] = '\0';
+      gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: Sending (%d bytes):", enc_len, buf);
+      APR_BRIGADE_INSERT_TAIL(brig_out, bkt_out);
+
+      /* Send the output brigade */
+      gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_filter: Passing the application data brigade");
+      if (OK != (ret = ap_pass_brigade(f->next, brig_out))) {
+	apr_brigade_cleanup(brig_in);
+	apr_brigade_cleanup(brig_out);
+	return ret;
+      }
+    }
+
+  /* Make sure we don't see the same data again */
+  apr_brigade_cleanup(brig_in);
+  return OK;
+}
 
-      /* write */
-      buf = apr_bucket_alloc(len, c->bucket_alloc);
-      for(n=0 ; n < len ; ++n)
-	buf[n] = apr_toupper(data[n]);
+/* gssweb_add_filter() -- Hook to add our output filter to the request
+ * (r). Called for all error responses through the
+ * gssweb_insert_error_filter hook.
+ */
+static void
+gssweb_add_filter(request_rec *r) 
+{
+  gss_conn_ctx conn_ctx = NULL;
 
-      pbktOut = apr_bucket_heap_create(buf, len, apr_bucket_free,
-				       c->bucket_alloc);
-      APR_BRIGADE_INSERT_TAIL(pbbOut,pbktOut);
-    }
+  /* Get the context for this request, if any */
+  conn_ctx = gss_retrieve_conn_ctx(r);
 
-  /* Q: is there any advantage to passing a brigade for each bucket? 
-   * A: obviously, it can cut down server resource consumption, if this
-   * experimental module was fed a file of 4MB, it would be using 8MB for
-   * the 'read' buckets and the 'write' buckets.
-   *
-   * Note it is more efficient to consume (destroy) each bucket as it's
-   * processed above than to do a single cleanup down here.  In any case,
-   * don't let our caller pass the same buckets to us, twice;
-   */
-  apr_brigade_cleanup(pbbIn);
-  return ap_pass_brigade(f->next,pbbOut);
+  /* Add the output filter */
+  ap_add_output_filter("gssweb_auth_filter", (void *)conn_ctx, r, r->connection);
+  return;
 }
 
 /* gssweb_authenticate_user() -- Hook to perform actual user
  * authentication.  Will be called once for each round trip in the GSS
  * authentication loop.  Reads the tokend from the request, calls
  * gss_accept_sec_context(), and stores the output token and context
- * in the user data area. Registers output filter to send the GSS
+ * in the user data areas.  Adds output filter to send the GSS
  * output token back to the client.
  */
 static int
 gssweb_authenticate_user(request_rec *r) 
 {
-  gss_auth_config *conf = 
-    (gss_auth_config *) ap_get_module_config(r->per_dir_config,
-						&auth_gssweb_module);
   const char *auth_line = NULL;
-  const char *type = NULL;
   char *auth_type = NULL;
   char *negotiate_ret_value = NULL;
   gss_conn_ctx conn_ctx = NULL;
@@ -216,82 +356,74 @@ gssweb_authenticate_user(request_rec *r)
   OM_uint32 major_status, minor_status, minor_status2;
   gss_buffer_desc input_token = GSS_C_EMPTY_BUFFER;
   gss_buffer_desc output_token = GSS_C_EMPTY_BUFFER;
-  const char *posted_token = NULL;
   gss_name_t client_name = GSS_C_NO_NAME;
   gss_cred_id_t delegated_cred = GSS_C_NO_CREDENTIAL;
-  gss_cred_id_t server_creds = GSS_C_NO_CREDENTIAL;
   OM_uint32 ret_flags = 0;
   unsigned int nonce;
+  int release_output_token = 1;
+  gss_auth_config *conf = NULL;
 
   gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "Entering GSSWeb authentication");
-   
-  /* Check if this is for our auth type */
-  type = ap_auth_type(r);
-  if (type == NULL || strcasecmp(type, "GSSWeb") != 0) {
-        gss_log(APLOG_MARK, APLOG_DEBUG, 0, r,
-		"AuthType '%s' is not GSSWeb, bailing out",
-		(type) ? type : "(NULL)");
 
-        return DECLINED;
-  }
+  /* Get the module configuration */
+  conf = (gss_auth_config *) ap_get_module_config(r->per_dir_config,
+						  &auth_gssweb_module);
 
-  /* Set up a GSS context for this request, if there isn't one already */
-  conn_ctx = gss_get_conn_ctx(r);
-  if (conn_ctx == NULL) {
-    gss_log(APLOG_MARK, APLOG_ERR, 0, r, "Failed to create internal context: probably not enough memory");
-    return HTTP_INTERNAL_SERVER_ERROR;
+  /* Check if this is for our auth type */
+  auth_type = (char *)ap_auth_type(r);
+  if (auth_type == NULL || strcasecmp(auth_type, "GSSWeb") != 0) {
+        gss_log(APLOG_MARK, APLOG_DEBUG, 0, r,
+		"gssweb_authenticate_user: AuthType '%s' is not GSSWeb, bailing out",
+		(auth_type) ? auth_type : "(NULL)");
+        ret = DECLINED;
+	goto end;
   }
 
   /* Read the token and nonce from the POST */
   if (0 != gssweb_get_post_data(r, &nonce, &input_token)) {
+    gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_user: Unable to read nonce or input token.");
     ret = HTTP_UNAUTHORIZED;
-    gss_log(APLOG_MARK, APLOG_ERR, 0, r, "Unable to read nonce or input token.");
     goto end;
   }
-  gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "GSSWeb nonce value = %u.", nonce);
-   
-  /* If the nonce is set and doesn't match, start over */
-  if ((0 != conn_ctx->nonce) && (conn_ctx->nonce != nonce)) {
-    if (GSS_C_NO_CONTEXT != conn_ctx->context) {
-      gss_delete_sec_context(&minor_status, &conn_ctx->context, GSS_C_NO_BUFFER);
-    }
-    conn_ctx->context = GSS_C_NO_CONTEXT;
-    conn_ctx->state = GSS_CTX_EMPTY;
-    conn_ctx->user = NULL;
-    if (0 != conn_ctx->output_token.length) {
-      gss_release_buffer(&minor_status, &conn_ctx->output_token);
+  gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_user: GSSWeb nonce value = %u.", nonce);
+
+  /* Retrieve the existing context (if any) and see if it matches this request */
+  gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_user: Attempting to retrieve GSS context");
+  conn_ctx = gss_retrieve_conn_ctx(r);
+
+  /* If there is no matching context, create a new one */
+  if ((NULL == conn_ctx) || 
+      (conn_ctx->nonce != nonce)) {
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_user: Creating a new GSS context");
+    if (conn_ctx)
+      gss_cleanup_conn_ctx(conn_ctx);
+    if (NULL == (conn_ctx = gss_create_conn_ctx (r, conf))) {
+      gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_user: Failed to create GSS context");
+      ret = HTTP_INTERNAL_SERVER_ERROR;
+      goto end;
     }
-      conn_ctx->output_token = GSS_C_EMPTY_BUFFER;
   }
- 
+
+  if (NULL == conn_ctx) {
+      gss_log(APLOG_MARK, APLOG_ERR, 0, r, "gssweb_authenticate_user: ERROR -- no GSS context");
+      goto end;
+  }
+
   /* If the output filter reported an internal server error, return it */
-  if (GSS_CTX_ERROR == conn_ctx->state) {
+  if (GSS_FILT_ERROR == conn_ctx->filter_stat) {
     ret = HTTP_INTERNAL_SERVER_ERROR;
     gss_log(APLOG_MARK, APLOG_ERR, 0, r,
-	    "Output filter returned internal server error, reporting.");
+	    "gssweb_authenticate_user: Output filter returned error, reporting.");
     goto end;
   }
 
-  /* If this is a new authentiction cycle, set-up the output filter. */
-  if (GSS_CTX_EMPTY == conn_ctx->state)
- {
-   ap_add_output_filter("gssweb_auth_filter",conn_ctx->ctx,r,r->connection);
-   ap_register_output_filter("gssweb_auth_filter",gssweb_authenticate_filter,AP_FTYPE_RESOURCE);
-
-  }
+  /* Add the output filter to this request (only applies to non-error returns) */
+  ap_add_output_filter("gssweb_auth_filter", (void *)conn_ctx, r, r->connection);
 
-  /* Acquire server credentials */
-  ret = get_gss_creds(r, conf, &server_creds);
-  if (ret)
-    goto end;
-    
-  /* Decode input token */
-  input_token.length = apr_base64_decode(input_token.value, posted_token);
-  
   /* Call gss_accept_sec_context */
   major_status = gss_accept_sec_context(&minor_status,
-					&ctx->context,
-					server_creds,
+					&conn_ctx->context,
+					conn_ctx->server_creds,
 					&input_token,
 					GSS_C_NO_CHANNEL_BINDINGS,
 					NULL,
@@ -301,55 +433,67 @@ gssweb_authenticate_user(request_rec *r)
 					NULL,
 					&delegated_cred);
   gss_log(APLOG_MARK, APLOG_DEBUG, 0, r,
-	  "Client %s us their credential",
+	  "gssweb_authenticate_user: Client %s us their credential",
 	  (ret_flags & GSS_C_DELEG_FLAG) ? "delegated" : "didn't delegate");
-
+  if (output_token.length >= 4) {
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_user: First four bytes of output token are: %.2x %.2x %.2x %.2x", ((char *)output_token.value)[0], ((char *)output_token.value)[1], ((char *)output_token.value)[2], ((char *)output_token.value)[3]);
+  } else {
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_user: No output token");
+  }
+ 
   if (GSS_ERROR(major_status)) {
     gss_log(APLOG_MARK, APLOG_ERR, 0, r,
 	    "%s", get_gss_error(r, major_status, minor_status,
-				"Failed to establish authentication"));
-    gss_delete_sec_context(&minor_status, &ctx->context, GSS_C_NO_BUFFER);
-    ctx->context = GSS_C_NO_CONTEXT;
-    ctx->state = GSS_CTX_EMPTY;
+				"gssweb_authenticate_user: Failed to establish authentication"));
+    gss_delete_sec_context(&minor_status, &conn_ctx->context, GSS_C_NO_BUFFER);
+    conn_ctx->context = GSS_C_NO_CONTEXT;
+    conn_ctx->state = GSS_CTX_EMPTY;
     ret = HTTP_UNAUTHORIZED;
     goto end;
+    gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_user: Decoding ouput token.");
   }
 
+  gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "gssweb_authenticate_user: Got sec context, storing nonce and output token.");
+
   /* Store the nonce & ouput token in the stored context */
   conn_ctx->nonce = nonce;
   conn_ctx->output_token = output_token;
-    
+  release_output_token = 0;
+
   /* If we aren't done yet, go around again */
   if (major_status & GSS_S_CONTINUE_NEEDED) {
-    ctx->state = GSS_CTX_IN_PROGRESS;
+    conn_ctx->state = GSS_CTX_IN_PROGRESS;
     ret = HTTP_UNAUTHORIZED;
     goto end;
   }
 
-  ctx->state = GSS_CTX_ESTABLISHED;
-  // TBD -- set the user and authtype in the request structure
+  conn_ctx->state = GSS_CTX_ESTABLISHED;
+	r->user = apr_pstrdup(r->pool, conn_ctx->user);
+	r->ap_auth_type = "GSSWeb";
   ret = OK;
 
  end:
   if (delegated_cred)
     gss_release_cred(&minor_status, &delegated_cred);
   
-  if (output_token.length) 
+  if ((release_output_token) && (output_token.length))
     gss_release_buffer(&minor_status, &output_token);
     
   if (client_name != GSS_C_NO_NAME)
     gss_release_name(&minor_status, &client_name);
 
-  if (server_creds != GSS_C_NO_CREDENTIAL)
-    gss_release_cred(&minor_status, &server_creds);
-
   return ret;
 }
 
 static void
 gssweb_register_hooks(apr_pool_t *p)
 {
-    ap_hook_check_user_id(gssweb_authenticate_user, NULL, NULL, APR_HOOK_MIDDLE);
+  /* register the gssweb output filter */
+  ap_register_output_filter("gssweb_auth_filter", gssweb_authenticate_filter, NULL, AP_FTYPE_RESOURCE);
+
+  /* register hooks */
+  ap_hook_check_user_id(gssweb_authenticate_user, NULL, NULL, APR_HOOK_MIDDLE);
+  ap_hook_insert_error_filter(gssweb_add_filter, NULL, NULL, APR_HOOK_MIDDLE);
 }
 
 module AP_MODULE_DECLARE_DATA auth_gssweb_module = {