* POSSIBILITY OF SUCH DAMAGE.
*/
+/*
+ * 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
+ * authentication in web applications. The module consists of two
+ * components: the hook function (gssweb_authenticate_user) that does
+ * most of the work, and an output filter (gssweb_authenticate_filter)
+ * that is registered by the hook function to send the output token
+ * back to the client in a json message that wraps the original
+ * response content.
+ *
+ * This module uses a simple protocol between the client and server
+ * to exchange GSS tokens and nonce information. The protocol is
+ * described in the protocol.txt file included with module source.
+ */
+
#include "mod_auth_gssweb.h"
module AP_MODULE_DECLARE_DATA auth_gssweb_module;
{ NULL }
};
+
+#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.
+ */
+static int gssweb_read_post(request_rec *r, const char **rbuf)
+{
+ int rc;
+ if ((rc = ap_setup_client_block(r, REQUEST_CHUNKED_ERROR)) != OK) {
+ 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) {
+ rsize = length - rpos;
+ }
+ else {
+ rsize = len_read;
+ }
+ memcpy((char*)*rbuf + rpos, argsbuffer, rsize);
+ rpos += rsize;
+ }
+ ap_kill_timeout(r);
+ }
+ return rc;
+}
+
+/* gssweb_get_post_data() -- Gets the token and nonce from the request
+ * data.
+ */
+static int gssweb_get_post_data(request_rec *r, int *nonce, gss_buffer_desc *input_token)
+{
+ const char *data;
+ const char *key, *val, *type;
+ int rc = 0;
+
+ if(r->method_number != M_POST) {
+ return DECLINED;
+ }
+
+ type = ap_table_get(r->headers_in, "Content-Type");
+ if(strcasecmp(type, DEFAULT_ENCTYPE) != 0) {
+ return DECLINED;
+ }
+
+ if((rc = util_read(r, &data)) != OK) {
+ return rc;
+ }
+ if(*tab) {
+ ap_clear_table(*tab);
+ }
+ else {
+ *tab = ap_make_table(r->pool, 8);
+ }
+ while(*data && (val = ap_getword(r->pool, &data, '&'))) {
+ key = ap_getword(r->pool, &val, '=');
+ ap_unescape_url((char*)key);
+ ap_unescape_url((char*)val);
+ ap_table_merge(*tab, key, val);
+ }
+ return OK;
+}
+
+/* gssweb_authenticate_filter() -- Output filter for gssweb authentication.
+ * Wraps original response in JSON -- adding JSON to the beginning of the
+ * response, escapes double quotes in the original response, and adds JSON
+ * to the end of the response. Handles responses that involve more than
+ * 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)
+{
+ request_rec *r = f->r;
+ conn_rec *c = r->connection;
+ apr_bucket *pbktIn;
+ apr_bucket_brigade *pbbOut;
+
+ 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))
+ {
+ const char *data;
+ apr_size_t len;
+ char *buf;
+ apr_size_t n;
+ apr_bucket *pbktOut;
+
+ if(APR_BUCKET_IS_EOS(pbktIn))
+ {
+ apr_bucket *pbktEOS=apr_bucket_eos_create(c->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(pbbOut,pbktEOS);
+ continue;
+ }
+ /* read */
+ apr_bucket_read(pbktIn,&data,&len,APR_BLOCK_READ);
+
+ /* write */
+ buf = apr_bucket_alloc(len, c->bucket_alloc);
+ for(n=0 ; n < len ; ++n)
+ buf[n] = apr_toupper(data[n]);
+
+ pbktOut = apr_bucket_heap_create(buf, len, apr_bucket_free,
+ c->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(pbbOut,pbktOut);
+ }
+
+ /* 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);
+}
+
+/* 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
+ * output token back to the client.
+ */
static int
-gssweb_authenticate_user(request_rec *r)
+gssweb_authenticate_user(request_rec *r)
{
- gss_auth_config *conf =
- (gss_auth_config *) ap_get_module_config(r->per_dir_config,
+ 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;
- int ret;
- 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;
- int ret;
- 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;
-
- gss_log(APLOG_MARK, APLOG_DEBUG, 0, r, "Entering GSSWeb authentication");
+ const char *auth_line = NULL;
+ const char *type = NULL;
+ char *auth_type = NULL;
+ char *negotiate_ret_value = NULL;
+ gss_conn_ctx conn_ctx = NULL;
+ int ret;
+ 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;
+
+ 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) {
+ /* 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;
- }
-
- /* 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;
- }
+ }
- /* Set-up the output filter, if we haven't already */
- if (GSS_CTX_EMPTY == conn_ctx->state) {
+ /* 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;
+ }
- // TBD -- Set-up the output filter
+ /* Read the token and nonce from the POST */
+ if (0 != gssweb_get_post_data(r, &nonce, &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);
}
+ conn_ctx->output_token = GSS_C_EMPTY_BUFFER;
+ }
+
+ /* If the output filter reported an internal server error, return it */
+ if (GSS_CTX_ERROR == conn_ctx->state) {
+ ret = HTTP_INTERNAL_SERVER_ERROR;
+ gss_log(APLOG_MARK, APLOG_ERR, 0, r,
+ "Output filter returned internal server error, reporting.");
+ goto end;
+ }
- /* Read the token and nonce from the POST */
- //TBD -- gss_log the values
+ /* 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);
- /* 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 (NULL != conn_ctx->output_token) {
- // TBD -- release the output token
- }
- conn_ctx->output_token = NULL;
- }
- conn_ctx->nonce = nonce;
-
- /* If the output filter reported an internal server error, return it */
- if (GSS_CTX_ERROR == conn_ctx->state) {
- ret = HTTP_INTERNAL_SERVER_ERROR;
- gss_log(APLOG_MARK, APLOG_ERR, 0, r,
- "Output filter returned internal server error, reporting.");
- goto end;
- }
+ }
- /* 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,
- &input_token,
- GSS_C_NO_CHANNEL_BINDINGS,
- NULL,
- NULL,
- &output_token,
- &ret_flags,
- NULL,
- &delegated_cred);
- gss_log(APLOG_MARK, APLOG_DEBUG, 0, r,
- "Client %s us their credential",
- (ret_flags & GSS_C_DELEG_FLAG) ? "delegated" : "didn't delegate");
-
- 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;
- ret = HTTP_UNAUTHORIZED;
- goto end;
- }
+ /* 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,
+ &input_token,
+ GSS_C_NO_CHANNEL_BINDINGS,
+ NULL,
+ NULL,
+ &output_token,
+ &ret_flags,
+ NULL,
+ &delegated_cred);
+ gss_log(APLOG_MARK, APLOG_DEBUG, 0, r,
+ "Client %s us their credential",
+ (ret_flags & GSS_C_DELEG_FLAG) ? "delegated" : "didn't delegate");
- /* Store the token & nonce in the stored context */
- conn_ctx.output_token = &output_token;
- conn_ctx.nonce = nonce;
+ 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;
+ ret = HTTP_UNAUTHORIZED;
+ goto end;
+ }
- /* If we aren't done yet, go around again */
- if (major_status & GSS_S_CONTINUE_NEEDED) {
- ctx->state = GSS_CTX_IN_PROGRESS;
- ret = HTTP_UNAUTHORIZED;
- goto end;
- }
+ /* Store the nonce & ouput token in the stored context */
+ conn_ctx->nonce = nonce;
+ conn_ctx->output_token = output_token;
+
+ /* If we aren't done yet, go around again */
+ if (major_status & GSS_S_CONTINUE_NEEDED) {
+ ctx->state = GSS_CTX_IN_PROGRESS;
+ ret = HTTP_UNAUTHORIZED;
+ goto end;
+ }
- ctx->state = GSS_CTX_ESTABLISHED;
- ret = OK;
+ ctx->state = GSS_CTX_ESTABLISHED;
+ // TBD -- set the user and authtype in the request structure
+ ret = OK;
end:
if (delegated_cred)
- gss_release_cred(&minor_status, &delegated_cred);
-
+ gss_release_cred(&minor_status, &delegated_cred);
+
if (output_token.length)
- gss_release_buffer(&minor_status, &output_token);
-
+ gss_release_buffer(&minor_status, &output_token);
+
if (client_name != GSS_C_NO_NAME)
- gss_release_name(&minor_status, &client_name);
+ gss_release_name(&minor_status, &client_name);
if (server_creds != GSS_C_NO_CREDENTIAL)
- gss_release_cred(&minor_status, &server_creds);
+ gss_release_cred(&minor_status, &server_creds);
return ret;
-
}
static void
projects / mod_auth_kerb.cvs / .git / commitdiff