kadm5_hook: new plugin interface

Implement http://k5wiki.kerberos.org/wiki/Projects/Kadmin_hook_interface

This provides an interface that allows a plugin to track kadmin
operations. This can be used for projects like the krb5-sync project.

ticket: 6791

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@24375 dc483132-0cff-0310-8789-dd5450dbe970

6 files changed, 323 insertions, 10 deletions

diff --git a/src/lib/kadm5/server_internal.h b/src/lib/kadm5/server_internal.h
index fd0f7b4ae..59c7b0512 100644
--- a/src/lib/kadm5/server_internal.h
+++ b/src/lib/kadm5/server_internal.h
@@ -37,6 +37,8 @@
 /* A pwqual_handle represents a password quality plugin module. */
 typedef struct pwqual_handle_st *pwqual_handle;
 
+typedef struct kadm5_hook_handle_st *kadm5_hook_handle;
+
 typedef struct _kadm5_server_handle_t {
     krb5_ui_4       magic_number;
     krb5_ui_4       struct_version;
@@ -47,6 +49,7 @@ typedef struct _kadm5_server_handle_t {
     struct _kadm5_server_handle_t *lhandle;
     char **db_args;
     pwqual_handle   *qual_handles;
+    kadm5_hook_handle *hook_handles;
 } kadm5_server_handle_rec, *kadm5_server_handle_t;
 
 #define OSA_ADB_PRINC_VERSION_1  0x12345C01
@@ -198,4 +201,56 @@ krb5_error_code
 pwqual_princ_initvt(krb5_context context, int maj_ver, int min_ver,
                     krb5_plugin_vtable vtable);
 
+/** @{
+ * @name kadm5_hook plugin support
+ */
+
+/**Load all kadm5_hook plugins*/
+krb5_error_code
+k5_kadm5_hook_load(krb5_context context,
+                   kadm5_hook_handle **handles_out);
+
+/** Free handles allocated by k5_kadm5_hook_load()*/
+void
+k5_kadm5_hook_free_handles(krb5_context context, kadm5_hook_handle *handles);
+
+/**Call the chpass entry point on every kadm5_hook in @a handles*/
+kadm5_ret_t
+k5_kadm5_hook_chpass (krb5_context context,
+                      kadm5_hook_handle *handles,
+                      int stage, krb5_principal princ,
+                      krb5_boolean keepold,
+                      int n_ks_tuple,
+                      krb5_key_salt_tuple *ks_tuple,
+                      const char *newpass);
+
+/** Call the create entry point for kadm5_hook_plugins*/
+kadm5_ret_t
+k5_kadm5_hook_create (krb5_context context,
+                      kadm5_hook_handle *handles,
+                      int stage,
+                      kadm5_principal_ent_t princ, long mask,
+                      int n_ks_tuple,
+                      krb5_key_salt_tuple *ks_tuple,
+                      const char *newpass);
+
+/** Call modify kadm5_hook entry point*/
+kadm5_ret_t
+k5_kadm5_hook_modify (krb5_context context,
+                      kadm5_hook_handle *handles,
+                      int stage,
+                      kadm5_principal_ent_t princ, long mask);
+
+/** call remove kadm5_hook entry point*/
+kadm5_ret_t
+k5_kadm5_hook_remove (krb5_context context,
+                      kadm5_hook_handle *handles,
+                      int stage,
+                      krb5_principal princ);
+
+/** @}*/
+
+
+
+
 #endif /* __KADM5_SERVER_INTERNAL_H__ */
diff --git a/src/lib/kadm5/srv/Makefile.in b/src/lib/kadm5/srv/Makefile.in
index a513035d5..378e03c76 100644
--- a/src/lib/kadm5/srv/Makefile.in
+++ b/src/lib/kadm5/srv/Makefile.in
@@ -28,6 +28,7 @@ SHLIB_RDIRS=$(KRB5_LIBDIR)
 RELDIR=kadm5/srv
 
 SRCS =	$(srcdir)/pwqual.c \
+	$(srcdir)/kadm5_hook.c \
 	$(srcdir)/pwqual_dict.c \
 	$(srcdir)/pwqual_empty.c \
 	$(srcdir)/pwqual_hesiod.c \
@@ -47,6 +48,7 @@ OBJS =	pwqual.$(OBJEXT) \
 	pwqual_empty.$(OBJEXT) \
 	pwqual_hesiod.$(OBJEXT) \
 	pwqual_princ.$(OBJEXT) \
+	kadm5_hook.$(OBJEXT) \
 	svr_policy.$(OBJEXT) \
 	svr_principal.$(OBJEXT) \
 	server_acl.$(OBJEXT) \
@@ -63,6 +65,7 @@ STLIBOBJS = \
 	pwqual_empty.o \
 	pwqual_hesiod.o \
 	pwqual_princ.o \
+	kadm5_hook.o \
 	svr_policy.o \
 	svr_principal.o \
 	server_acl.o \
diff --git a/src/lib/kadm5/srv/kadm5_hook.c b/src/lib/kadm5/srv/kadm5_hook.c
new file mode 100644
index 000000000..b86ab4297
--- /dev/null
+++ b/src/lib/kadm5/srv/kadm5_hook.c
@@ -0,0 +1,189 @@
+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+ * lib/kadm5/srv/kadm5_hook.c
+ *
+ * Copyright (C) 2010 by the Massachusetts Institute of Technology.
+ * All rights reserved.
+ *
+ * Export of this software from the United States of America may
+ *   require a specific license from the United States Government.
+ *   It is the responsibility of any person or organization contemplating
+ *   export to obtain such a license before exporting.
+ *
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of M.I.T. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  Furthermore if you modify this software you must label
+ * your software as modified software and not distribute it in such a
+ * fashion that it might be confused with the original M.I.T. software.
+ * M.I.T. makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ */
+/* Consumer interface for kadm5_hook plugins*/
+
+
+#include "k5-int.h"
+#include "server_internal.h"
+#include <krb5/kadm5_hook_plugin.h>
+#include <adm_proto.h>
+#include <syslog.h>
+
+struct kadm5_hook_handle_st {
+    kadm5_hook_vftable_1 vt;
+    kadm5_hook_modinfo *data;
+};
+
+krb5_error_code
+k5_kadm5_hook_load(krb5_context context,
+                   kadm5_hook_handle **handles_out)
+{
+    krb5_error_code ret;
+    krb5_plugin_initvt_fn *modules = NULL, *mod;
+    size_t count;
+    kadm5_hook_handle *list = NULL, handle = NULL;
+
+    *handles_out = NULL;
+
+    ret = k5_plugin_load_all(context, PLUGIN_INTERFACE_KADM5_HOOK, &modules);
+    if (ret != 0)
+        goto cleanup;
+
+    /* Allocate a large enough list of handles. */
+    for (count = 0; modules[count] != NULL; count++);
+    list = k5alloc((count + 1) * sizeof(*list), &ret);
+    if (list == NULL)
+        goto cleanup;
+
+    /* For each module, allocate a handle, initialize its vtable, and initialize the module*/
+    count = 0;
+    for (mod = modules; *mod != NULL; mod++) {
+        handle = k5alloc(sizeof(*handle), &ret);
+        if (handle == NULL)
+            goto cleanup;
+        ret = (*mod)(context, 1, 1, (krb5_plugin_vtable)&handle->vt);
+        if (ret != 0) {         /* Failed vtable init is non-fatal. */
+            free(handle);
+            handle = NULL;
+            continue;
+        }
+        handle->data = NULL;
+        if (handle->vt.init != NULL) {
+            ret = handle->vt.init(context,  &handle->data);
+            if (ret != 0)       /* Failed dictionary binding is fatal. */
+                goto cleanup;
+        }
+        list[count++] = handle;
+        list[count] = NULL;
+        handle = NULL;
+    }
+    list[count] = NULL;
+
+    ret = 0;
+    *handles_out = list;
+    list = NULL;
+
+cleanup:
+    free(handle);
+    k5_plugin_free_modules(context, modules);
+    k5_kadm5_hook_free_handles(context, list);
+    return ret;
+}
+
+void
+k5_kadm5_hook_free_handles(krb5_context context, kadm5_hook_handle *handles)
+{
+    kadm5_hook_handle *hp, handle;
+
+    if (handles == NULL)
+        return;
+    for (hp = handles; *hp != NULL; hp++) {
+        handle = *hp;
+        if (handle->vt.fini != NULL)
+            handle->vt.fini(context, handle->data);
+    }
+    free(handles);
+}
+
+static void
+log_failure(krb5_context context,
+            const char *name,
+            const char *function,
+            krb5_error_code ret)
+{
+    const char *e = krb5_get_error_message(context, ret);
+    if (e)
+        krb5_klog_syslog(LOG_ERR, "kadm5_hook %s failed postcommit %s: %s",
+                         name, function, e);
+    krb5_free_error_message(context, e);
+}
+
+#define ITERATE(operation, params)                                      \
+    for (; *handles; handles++) {                                       \
+        kadm5_hook_handle h = *handles;                                 \
+        krb5_error_code ret = 0;                                        \
+        if (h->vt.operation) {                                          \
+            ret = h->vt.operation params;                               \
+        }                                                               \
+        if (ret) {                                                      \
+            if (stage == KADM5_HOOK_STAGE_PRECOMMIT)                    \
+                return ret;                                             \
+            else log_failure(context, h->vt.name, #operation, ret);     \
+        }                                                               \
+    }
+
+
+kadm5_ret_t
+k5_kadm5_hook_chpass (krb5_context context,
+                      kadm5_hook_handle *handles,
+                      int stage, krb5_principal princ,
+                      krb5_boolean keepold,
+                      int n_ks_tuple,
+                      krb5_key_salt_tuple *ks_tuple,
+                      const char *newpass)
+{
+    ITERATE(chpass, (context, h->data,
+                     stage, princ, keepold,
+                     n_ks_tuple, ks_tuple, newpass));
+    return 0;
+}
+
+kadm5_ret_t
+k5_kadm5_hook_create (krb5_context context,
+                      kadm5_hook_handle *handles,
+                      int stage,
+                      kadm5_principal_ent_t princ, long mask,
+                      int n_ks_tuple,
+                      krb5_key_salt_tuple *ks_tuple,
+                      const char *newpass)
+{
+    ITERATE(create, (context, h->data,
+                     stage, princ, mask, n_ks_tuple, ks_tuple, newpass));
+    return 0;
+}
+
+kadm5_ret_t
+k5_kadm5_hook_modify (krb5_context context,
+                      kadm5_hook_handle *handles,
+                      int stage,
+                      kadm5_principal_ent_t princ, long mask)
+{
+    ITERATE(modify, (context, h->data,
+                     stage, princ, mask));
+    return 0;
+}
+
+kadm5_ret_t
+k5_kadm5_hook_remove (krb5_context context,
+                      kadm5_hook_handle *handles,
+                      int stage,
+                      krb5_principal princ)
+{
+    ITERATE(remove, (context, h->data,
+                     stage, princ));
+    return 0;
+}
diff --git a/src/lib/kadm5/srv/server_init.c b/src/lib/kadm5/srv/server_init.c
index 9ebc13eea..21604a32c 100644
--- a/src/lib/kadm5/srv/server_init.c
+++ b/src/lib/kadm5/srv/server_init.c
@@ -317,8 +317,18 @@ kadm5_ret_t kadm5_init(krb5_context context, char *client_name, char *pass,
         return ret;
     }
 
+    ret = k5_kadm5_hook_load(context,&handle->hook_handles);
+    if (ret) {
+        krb5_db_fini(handle->context);
+        krb5_free_principal(handle->context, handle->current_caller);
+        free_db_args(handle);
+        free(handle);
+        return ret;
+    }
+
     ret = init_pwqual(handle);
     if (ret) {
+        k5_kadm5_hook_free_handles(context, handle->hook_handles);
         krb5_db_fini(handle->context);
         krb5_free_principal(handle->context, handle->current_caller);
         free_db_args(handle);
@@ -339,6 +349,7 @@ kadm5_ret_t kadm5_destroy(void *server_handle)
 
     destroy_pwqual(handle);
 
+    k5_kadm5_hook_free_handles(handle->context, handle->hook_handles);
     adb_policy_close(handle);
     krb5_db_fini(handle->context);
     krb5_free_principal(handle->context, handle->current_caller);
diff --git a/src/lib/kadm5/srv/svr_principal.c b/src/lib/kadm5/srv/svr_principal.c
index 132078ce3..6ba2c43dc 100644
--- a/src/lib/kadm5/srv/svr_principal.c
+++ b/src/lib/kadm5/srv/svr_principal.c
@@ -4,11 +4,7 @@
  *
  * $Header$
  */
-
-#if !defined(lint) && !defined(__CODECENTER__)
-static char *rcsid = "$Header$";
-#endif
-
+#include <assert.h>
 #include        <sys/types.h>
 #include        <sys/time.h>
 #include        <errno.h>
@@ -25,6 +21,8 @@ static char *rcsid = "$Header$";
 
 #endif
 
+#include <krb5/kadm5_hook_plugin.h>
+
 #ifdef USE_VALGRIND
 #include <valgrind/memcheck.h>
 #else
@@ -393,6 +391,13 @@ kadm5_create_principal_3(void *server_handle,
     if (ret)
         goto cleanup;
 
+    ret = k5_kadm5_hook_create(handle->context, handle->hook_handles,
+                               KADM5_HOOK_STAGE_PRECOMMIT, entry, mask,
+                               n_ks_tuple?n_ks_tuple:handle->params.num_keysalts,
+                               n_ks_tuple?ks_tuple:handle->params.keysalts, password);
+    if (ret)
+        goto cleanup;
+
     /* populate the admin-server-specific fields.  In the OV server,
        this used to be in a separate database.  Since there's already
        marshalling code for the admin fields, to keep things simple,
@@ -440,6 +445,11 @@ kadm5_create_principal_3(void *server_handle,
         }
     }
 
+    (void) k5_kadm5_hook_create(handle->context, handle->hook_handles,
+                                KADM5_HOOK_STAGE_POSTCOMMIT, entry, mask,
+                                n_ks_tuple?n_ks_tuple:handle->params.num_keysalts,
+                                n_ks_tuple?ks_tuple:handle->params.keysalts, password);
+
 cleanup:
     krb5_db_free_principal(handle->context, kdb);
     if (have_polent)
@@ -466,6 +476,12 @@ kadm5_delete_principal(void *server_handle, krb5_principal principal)
 
     if ((ret = kdb_get_entry(handle, principal, &kdb, &adb)))
         return(ret);
+    ret = k5_kadm5_hook_remove(handle->context, handle->hook_handles,
+                               KADM5_HOOK_STAGE_PRECOMMIT, principal);
+    if (ret) {
+        kdb_free_entry(handle, kdb, &adb);
+        return ret;
+    }
 
     if ((adb.aux_attributes & KADM5_POLICY)) {
         if ((ret = kadm5_get_policy(handle->lhandle,
@@ -490,6 +506,11 @@ kadm5_delete_principal(void *server_handle, krb5_principal principal)
 
     kdb_free_entry(handle, kdb, &adb);
 
+    if (ret == 0)
+        (void) k5_kadm5_hook_remove(handle->context,
+                                    handle->hook_handles,
+                                    KADM5_HOOK_STAGE_POSTCOMMIT, principal);
+
     return ret;
 }
 
@@ -681,8 +702,15 @@ kadm5_modify_principal(void *server_handle,
     /* let the mask propagate to the database provider */
     kdb->mask = mask;
 
+    ret = k5_kadm5_hook_modify(handle->context, handle->hook_handles,
+                               KADM5_HOOK_STAGE_PRECOMMIT, entry, mask);
+    if (ret)
+        goto done;
+
     ret = kdb_put_entry(handle, kdb, &adb);
     if (ret) goto done;
+    (void) k5_kadm5_hook_modify(handle->context, handle->hook_handles,
+                                KADM5_HOOK_STAGE_POSTCOMMIT, entry, mask);
 
     ret = KADM5_OK;
 done:
@@ -834,7 +862,7 @@ kadm5_get_principal(void *server_handle, krb5_principal principal,
 
     if (mask & KADM5_KVNO)
         for (entry->kvno = 0, i=0; i<kdb->n_key_data; i++)
-            if (kdb->key_data[i].key_data_kvno > entry->kvno)
+            if ((krb5_kvno) kdb->key_data[i].key_data_kvno > entry->kvno)
                 entry->kvno = kdb->key_data[i].key_data_kvno;
 
     if (mask & KADM5_MKVNO) {
@@ -941,13 +969,14 @@ check_pw_reuse(krb5_context context,
     krb5_keyblock newkey, histkey;
     krb5_error_code ret;
 
-    for (x = 0; x < n_new_key_data; x++) {
+    assert (n_new_key_data >= 0);
+    for (x = 0; x < (unsigned) n_new_key_data; x++) {
         ret = krb5_dbe_decrypt_key_data(context, NULL, &(new_key_data[x]),
                                         &newkey, NULL);
         if (ret)
             return(ret);
         for (y = 0; y < n_pw_hist_data; y++) {
-            for (z = 0; z < pw_hist_data[y].n_key_data; z++) {
+            for (z = 0; z < (unsigned int) pw_hist_data[y].n_key_data; z++) {
                 ret = krb5_dbe_decrypt_key_data(context, hist_keyblock,
                                                 &pw_hist_data[y].key_data[z],
                                                 &histkey, NULL);
@@ -1170,7 +1199,7 @@ static kadm5_ret_t add_to_history(krb5_context context,
         knext = adb->old_key_next = 0;
     /* free the old pw history entry if it contains data */
     histp = &adb->old_keys[knext];
-    for (i = 0; i < histp->n_key_data; i++)
+    for (i = 0; i < (unsigned int) histp->n_key_data; i++)
         krb5_free_key_data_contents(context, &histp->key_data[i]);
     free(histp->key_data);
 
@@ -1472,9 +1501,22 @@ kadm5_chpass_principal_3(void *server_handle,
         KADM5_FAIL_AUTH_COUNT;
     /* | KADM5_CPW_FUNCTION */
 
+    ret = k5_kadm5_hook_chpass(handle->context, handle->hook_handles,
+                               KADM5_HOOK_STAGE_PRECOMMIT, principal, keepold,
+                               n_ks_tuple?n_ks_tuple:handle->params.num_keysalts,
+                               n_ks_tuple?ks_tuple:handle->params.keysalts,
+                               password);
+    if (ret)
+        goto done;
+
     if ((ret = kdb_put_entry(handle, kdb, &adb)))
         goto done;
 
+    (void) k5_kadm5_hook_chpass(handle->context, handle->hook_handles,
+                                KADM5_HOOK_STAGE_POSTCOMMIT, principal, keepold,
+                                n_ks_tuple?n_ks_tuple:handle->params.num_keysalts,
+                                n_ks_tuple?ks_tuple:handle->params.keysalts,
+                                password);
     ret = KADM5_OK;
 done:
     if (!hist_added && hist.key_data)
@@ -1608,9 +1650,21 @@ kadm5_randkey_principal_3(void *server_handle,
     kdb->mask = KADM5_KEY_DATA | KADM5_FAIL_AUTH_COUNT;
     /* | KADM5_RANDKEY_USED */;
 
+    ret = k5_kadm5_hook_chpass(handle->context, handle->hook_handles,
+                               KADM5_HOOK_STAGE_PRECOMMIT, principal, keepold,
+                               n_ks_tuple?n_ks_tuple:handle->params.num_keysalts,
+                               n_ks_tuple?ks_tuple:handle->params.keysalts,
+                               NULL);
+    if (ret)
+        goto done;
     if ((ret = kdb_put_entry(handle, kdb, &adb)))
         goto done;
 
+    (void) k5_kadm5_hook_chpass(handle->context, handle->hook_handles,
+                                KADM5_HOOK_STAGE_POSTCOMMIT, principal, keepold,
+                                n_ks_tuple?n_ks_tuple:handle->params.num_keysalts,
+                                n_ks_tuple?ks_tuple:handle->params.keysalts,
+                                NULL);
     ret = KADM5_OK;
 done:
     kdb_free_entry(handle, kdb, &adb);
diff --git a/src/lib/krb5/krb/plugin.c b/src/lib/krb5/krb/plugin.c
index 277da2472..0df393ad9 100644
--- a/src/lib/krb5/krb/plugin.c
+++ b/src/lib/krb5/krb/plugin.c
@@ -31,7 +31,8 @@
 #include "k5-int.h"
 
 const char *interface_names[PLUGIN_NUM_INTERFACES] = {
-    "pwqual"
+    "pwqual",
+    "kadm5_hook"
 };
 
 /* Return the context's interface structure for id, or NULL if invalid. */