Modify the preath plugin interface so that a plugin's context is

global to all the modules within a plugin.  Also, change the
client-side interface so that the preauth plugin context (once
created) lives the lifetime of a krb5_context.  This will allow
future changes that can set plugin parameters.  The client side
request context lives the lifetime of a call to krb5_get_init_creds().

Make the sample preauth plugins buildable outside the source tree.

Fix minor memory leak in sort_krb5_padata_sequence().

Add a prototype for krb5_do_preauth_tryagain() and change the plugin
interface.

Incorporates fixes from Nalin Dahyabhai <nalin@redhat.com> for leaks
of the function table pointers (rt #4566) and fix KDC crash (rt #4567)

ticket: 4566
ticket: 4567
ticket: 4587
Target_Version: 1.6
Tags: pullup

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@18754 dc483132-0cff-0310-8789-dd5450dbe970

2 files changed, 131 insertions, 38 deletions

diff --git a/src/include/k5-int.h b/src/include/k5-int.h
index f659e2e1e..884bd23c8 100644
--- a/src/include/k5-int.h
+++ b/src/include/k5-int.h
@@ -552,9 +552,6 @@ krb5int_locate_server (krb5_context, const krb5_data *realm,
 
 #endif /* KRB5_LIBOS_PROTO__ */
 
-#include <krb5/preauth_plugin.h>
-typedef struct _krb5_preauth_context krb5_preauth_context;
-
 /* new encryption provider api */
 
 struct krb5_enc_provider {
@@ -844,6 +841,71 @@ error(MIT_DES_KEYSIZE does not equal KRB5_MIT_DES_KEYSIZE)
 #ifndef KRB5_PREAUTH__
 #define KRB5_PREAUTH__
 
+#include <krb5/preauth_plugin.h>
+
+/* This structure lets us keep track of all of the modules which are loaded,
+ * turning the list of modules and their lists of implemented preauth types
+ * into a single list which we can walk easily. */
+typedef struct _krb5_preauth_context {
+    int n_modules;
+    struct _krb5_preauth_context_module {
+	/* Which of the possibly more than one preauth types which the
+	 * module supports we're using at this point in the list. */
+	krb5_preauthtype pa_type;
+	/* Encryption types which the client claims to support -- we
+	 * copy them directly into the krb5_kdc_req structure during
+	 * krb5_preauth_prepare_request(). */
+	krb5_enctype *enctypes;
+	/* The plugin's per-plugin context and a function to clear it. */
+	void *plugin_context;
+	void (*client_fini)(krb5_context context, void *plugin_context);
+	/* The module's table, and some of its members, copied here for
+	 * convenience when we populated the list. */
+	struct krb5plugin_preauth_client_ftable_v0 *ftable;
+	const char *name;
+	int flags, use_count;
+	krb5_error_code (*client_process)(krb5_context context,
+					  void *plugin_context,
+					  void *request_context,
+					  krb5_kdc_req *request,
+					  krb5_data *encoded_request_body,
+					  krb5_data *encoded_previous_request,
+					  krb5_pa_data *pa_data,
+					  krb5_prompter_fct prompter,
+					  void *prompter_data,
+					  preauth_get_as_key_proc gak_fct,
+					  void *gak_data,
+					  krb5_data *salt,
+					  krb5_data *s2kparams,
+					  krb5_keyblock *as_key,
+					  krb5_pa_data **out_pa_data);
+	krb5_error_code (*client_tryagain)(krb5_context context,
+					   void *plugin_context,
+					   void *request_context,
+					   krb5_kdc_req *request,
+					   krb5_data *encoded_request_body,
+					   krb5_data *encoded_previous_request,
+					   krb5_pa_data *old_pa_data,
+					   krb5_error *err_reply,
+					   krb5_prompter_fct prompter,
+					   void *prompter_data,
+					   preauth_get_as_key_proc gak_fct,
+					   void *gak_data,
+					   krb5_data *salt,
+					   krb5_data *s2kparams,
+					   krb5_keyblock *as_key,
+					   krb5_pa_data **new_pa_data);
+	void (*client_req_init)(krb5_context context, void *plugin_context,
+			       void **request_context);
+	void (*client_req_fini)(krb5_context context, void *plugin_context,
+			       void *request_context);
+	/* The per-pa_type context which the client_process() function
+	 * might allocate, which we'll need to clean up later by
+	 * calling the client_cleanup() function. */
+	void *request_context;
+    } *modules;
+} krb5_preauth_context;
+
 typedef struct _krb5_pa_enc_ts {
     krb5_timestamp	patimestamp;
     krb5_int32		pausec;
@@ -970,23 +1032,39 @@ void krb5int_populate_gic_opt (
     krb5_preauthtype *pre_auth_types, krb5_creds *creds);
 
 
-krb5_error_code krb5_do_preauth
-(krb5_context, krb5_preauth_context **, krb5_kdc_req *, krb5_data *,
-		krb5_data *, krb5_pa_data **, krb5_pa_data ***,
-		krb5_data *salt, krb5_data *s2kparams,
- krb5_enctype *,
-		krb5_keyblock *,
-		krb5_prompter_fct, void *,
-		krb5_gic_get_as_key_fct, void *);
+krb5_error_code KRB5_CALLCONV krb5_do_preauth
+	(krb5_context context,
+	 krb5_kdc_req *request,
+	 krb5_data *encoded_request_body,
+	 krb5_data *encoded_previous_request,
+	 krb5_pa_data **in_padata, krb5_pa_data ***out_padata,
+	 krb5_data *salt, krb5_data *s2kparams,
+	 krb5_enctype *etype, krb5_keyblock *as_key,
+	 krb5_prompter_fct prompter, void *prompter_data,
+	 krb5_gic_get_as_key_fct gak_fct, void *gak_data);
+krb5_error_code KRB5_CALLCONV krb5_do_preauth_tryagain
+	(krb5_context context,
+	 krb5_kdc_req *request,
+	 krb5_data *encoded_request_body,
+	 krb5_data *encoded_previous_request,
+	 krb5_pa_data **in_padata,
+	 krb5_error *err_reply,
+	 krb5_data *salt, krb5_data *s2kparams,
+	 krb5_enctype *etype, krb5_keyblock *as_key,
+	 krb5_prompter_fct prompter, void *prompter_data,
+	 krb5_gic_get_as_key_fct gak_fct, void *gak_data);
 void KRB5_CALLCONV krb5_init_preauth_context
-	(krb5_context, krb5_preauth_context **);
+	(krb5_context);
+void KRB5_CALLCONV krb5_free_preauth_context
+	(krb5_context);
 void KRB5_CALLCONV krb5_clear_preauth_context_use_counts
-	(krb5_context, krb5_preauth_context *);
+	(krb5_context);
 void KRB5_CALLCONV krb5_preauth_prepare_request
-	(krb5_context, krb5_preauth_context **,
-	 krb5_get_init_creds_opt *, krb5_kdc_req *);
-void KRB5_CALLCONV krb5_free_preauth_context
-	(krb5_context, krb5_preauth_context *);
+	(krb5_context, krb5_get_init_creds_opt *, krb5_kdc_req *);
+void KRB5_CALLCONV krb5_preauth_request_context_init
+	(krb5_context);
+void KRB5_CALLCONV krb5_preauth_request_context_fini
+	(krb5_context);
 
 void KRB5_CALLCONV krb5_free_sam_challenge
 	(krb5_context, krb5_sam_challenge * );
@@ -1079,6 +1157,7 @@ struct _krb5_context {
 
     /* preauth module stuff */
     struct plugin_dir_handle preauth_plugins;
+    krb5_preauth_context *preauth_context;
 
     /* error detail info */
     struct errinfo err;
diff --git a/src/include/krb5/preauth_plugin.h b/src/include/krb5/preauth_plugin.h
index 63600fead..d164192af 100644
--- a/src/include/krb5/preauth_plugin.h
+++ b/src/include/krb5/preauth_plugin.h
@@ -157,20 +157,27 @@ typedef struct krb5plugin_preauth_client_ftable_v0 {
      * to add support for. */
     krb5_enctype *enctype_list;
 
-    /* Per-module initialization/cleanup.  The init function is called
-     * by libkrb5 when the module is loaded, and the fini function is
-     * called before the module is unloaded.  Both are optional and
-     * may be called multiple times in case the module is used in
-     * multiple contexts.*/
-    krb5_error_code (*init)(krb5_context, krb5_preauthtype, void **);
-    void (*fini)(krb5_context, krb5_preauthtype, void *);
+    /* Per-plugin initialization/cleanup.  The init function is called
+     * by libkrb5 when the plugin is loaded, and the fini function is
+     * called before the plugin is unloaded.  Both are optional and
+     * may be called multiple times in case the plugin is used in
+     * multiple contexts.  The returned context lives the lifetime of
+     * the krb5_context */
+    krb5_error_code (*init)(krb5_context context, void **plugin_context);
+    void (*fini)(krb5_context context, void *plugin_context);
     /* A callback which returns flags indicating if the module is a "real" or
      * an "info" mechanism, and so on.  This function is called for each entry
      * in the client_pa_type_list. */
-    int (*flags)(krb5_context, krb5_preauthtype);
-    /* Clean up a client context.  Can be NULL. */
-    void (*cleanup)(krb5_context context, void *module_context,
+    int (*flags)(krb5_context context, krb5_preauthtype pa_type);
+    /* Per-request initialization/cleanup.  The request_init function is
+     * called when beginning to process a get_init_creds request and the
+     * request_fini function is called when processing of the request is
+     * complete.  This is optional.  It may be called multiple times in
+     * the lifetime of a krb5_context. */
+    void (*request_init)(krb5_context context, void *plugin_context,
 		    void **request_context);
+    void (*request_fini)(krb5_context context, void *plugin_context,
+		    void *request_context);
     /* Client function which processes server-supplied data in pa_data,
      * returns created data in out_pa_data, storing any of its own state in
      * client_context if data for the associated preauthentication type is
@@ -180,8 +187,8 @@ typedef struct krb5plugin_preauth_client_ftable_v0 {
      * function is called, because it is expected to only ever contain the data
      * obtained from a previous call to this function. */
     krb5_error_code (*process)(krb5_context context,
-			       void *module_context,
-			       void **request_context,
+			       void *plugin_context,
+			       void *request_context,
 			       krb5_kdc_req *request,
 			       krb5_data *encoded_request_body,
 			       krb5_data *encoded_previous_request,
@@ -189,8 +196,8 @@ typedef struct krb5plugin_preauth_client_ftable_v0 {
 			       krb5_prompter_fct prompter,
 			       void *prompter_data,
 			       preauth_get_as_key_proc gak_fct,
-			       krb5_data *salt, krb5_data *s2kparams,
 			       void *gak_data,
+			       krb5_data *salt, krb5_data *s2kparams,
 			       krb5_keyblock *as_key,
 			       krb5_pa_data **out_pa_data);
     /* Client function which can attempt to use e-data in the error response to
@@ -198,12 +205,19 @@ typedef struct krb5plugin_preauth_client_ftable_v0 {
      * it stores data in out_pa_data which is different data from the contents
      * of in_pa_data, then the client library will retransmit the request. */
     krb5_error_code (*tryagain)(krb5_context context,
-				void *module_context,
-				void **request_context,
+				void *plugin_context,
+				void *request_context,
 				krb5_kdc_req *request,
 				krb5_data *encoded_request_body,
-				krb5_error *error,
+				krb5_data *encoded_previous_request,
 				krb5_pa_data *in_pa_data,
+				krb5_error *error,
+				krb5_prompter_fct prompter,
+				void *prompter_data,
+				preauth_get_as_key_proc gak_fct,
+				void *gak_data,
+				krb5_data *salt, krb5_data *s2kparams,
+				krb5_keyblock *as_key,
 				krb5_pa_data **out_pa_data);
 } krb5plugin_preauth_client_ftable_v0;
 
@@ -223,11 +237,11 @@ typedef struct krb5plugin_preauth_server_ftable_v0 {
      * provide services for. */
     krb5_preauthtype *pa_type_list;
 
-    /* Per-module initialization/cleanup.  The init function is called by the
-     * KDC when the module is loaded, and the fini function is called before
-     * the module is unloaded.  Both are optional. */
-    krb5_error_code (*init_proc)(krb5_context, krb5_preauthtype, void **);
-    void (*fini_proc)(krb5_context, krb5_preauthtype, void *);
+    /* Per-plugin initialization/cleanup.  The init function is called by the
+     * KDC when the plugin is loaded, and the fini function is called before
+     * the plugin is unloaded.  Both are optional. */
+    krb5_error_code (*init_proc)(krb5_context, void **);
+    void (*fini_proc)(krb5_context, void *);
     /* Return the flags which the KDC should use for this module.  This is a
      * callback instead of a static value because the module may or may not
      * wish to count itself as a hardware preauthentication module (in other