Function to parse FAST for KDC requests

* Add fast_util to KDC
* export fast_req decoder from libkrb5
* Function to find a fast request, extract and use inner body
* functions to free and create kdc_request_state

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/fast@22124 dc483132-0cff-0310-8789-dd5450dbe970

diff --git a/src/kdc/Makefile.in b/src/kdc/Makefile.in
index 83e5f82d92eff77e72debf048380024b32ebfd4f..0d37fe1a1d7e99017723bb9abe3694d7cc96eab2 100644 (file)
--- a/src/kdc/Makefile.in
+++ b/src/kdc/Makefile.in
@@ -24,6 +24,7 @@ SRCS= \
        $(srcdir)/dispatch.c \
        $(srcdir)/do_as_req.c \
        $(srcdir)/do_tgs_req.c \
+       $(srcdir)/fast_util.c \
        $(srcdir)/kdc_util.c \
        $(srcdir)/kdc_preauth.c \
        $(srcdir)/main.c \
@@ -38,6 +39,7 @@ OBJS= \
        dispatch.o \
        do_as_req.o \
        do_tgs_req.o \
+       fast_util.o \
        kdc_util.o \
        kdc_preauth.o \
        main.o \

diff --git a/src/kdc/fast_util.c b/src/kdc/fast_util.c
new file mode 100644 (file)
index 0000000..7231dd4
--- /dev/null
+++ b/src/kdc/fast_util.c
@@ -0,0 +1,124 @@
+/*
+ * kdc/fast_util.c
+ *
+ * Copyright (C) 2009 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.
+ * 
+ * 
+ *
+ */
+
+#include <k5-int.h>
+
+#include "kdc_util.h"
+#include "extern.h"
+
+
+/*
+ * This function will find the fast and cookie padata and if fast is
+ * successfully processed, will throw away (and free) the outer
+ * request and update the pointer to point to the inner request.  The
+ * checksummed_data points to the data that is in the
+ * armored_fast_request checksum; either the pa-tgs-req or the
+ * kdc-req-body.
+ */
+
+krb5_error_code  kdc_find_fast
+(krb5_kdc_req **requestptr,  krb5_data *checksummed_data,
+ krb5_keyblock *tgs_subkey,
+ struct kdc_request_state *state)
+{
+    krb5_error_code retval = 0;
+    krb5_pa_data *fast_padata, *cookie_padata;
+    krb5_data scratch;
+    krb5_fast_req * fast_req = NULL;
+    krb5_kdc_req *request = *requestptr;
+
+    scratch.data = NULL;
+    fast_padata = find_pa_data(request->padata,
+                              KRB5_PADATA_FX_FAST);
+    cookie_padata = find_pa_data(request->padata, KRB5_PADATA_FX_COOKIE);
+        if (fast_padata == NULL)
+       return 0; /*no fast*/
+    
+    scratch.length = fast_padata->length;
+    scratch.data = (char *) fast_padata->contents;
+    retval = decode_krb5_fast_req(&scratch, &fast_req);
+    if (retval == 0) {
+       if ((fast_req->fast_options & UNSUPPORTED_CRITICAL_FAST_OPTIONS) !=0)
+           retval = KRB5KDC_ERR_UNKNOWN_CRITICAL_FAST_OPTION;
+    }
+    if (retval == 0 && cookie_padata != NULL) {
+       krb5_pa_data *new_padata = malloc(sizeof (krb5_pa_data));
+       if (new_padata != NULL) {
+           retval = ENOMEM;
+       } else {
+           new_padata->pa_type = KRB5_PADATA_FX_COOKIE;
+           new_padata->length = cookie_padata->length;
+           new_padata->contents = malloc(new_padata->length);
+           if (new_padata->contents == NULL) {
+               retval = ENOMEM;
+               free(new_padata);
+           } else {
+               memcpy(new_padata->contents, cookie_padata->contents, new_padata->length);
+               state->cookie = new_padata;
+           }
+       }
+    }
+    if (retval == 0) {
+       state->fast_options = fast_req->fast_options;
+       if (request->kdc_state == state)
+           request->kdc_state = NULL;
+       krb5_free_kdc_req( kdc_context, request);
+       *requestptr = fast_req->req_body;
+       fast_req->req_body = NULL;
+       
+    }
+    if (fast_req)
+       krb5_free_fast_req( kdc_context, fast_req);
+    return retval;
+}
+
+
+krb5_error_code kdc_make_rstate(struct kdc_request_state **out)
+{
+    struct kdc_request_state *state = malloc( sizeof(struct kdc_request_state));
+    if (state == NULL)
+       return ENOMEM;
+    memset( state, 0, sizeof(struct kdc_request_state));
+    *out = state;
+    return 0;
+}
+
+void kdc_free_rstate
+(struct kdc_request_state *s)
+{
+  if (s == NULL)
+    return;
+    if (s->armor_key)
+       krb5_free_keyblock(kdc_context, s->armor_key);
+    if (s->cookie) {
+       free(s->cookie->contents);
+       free(s->cookie);
+    }
+    free(s);
+}

diff --git a/src/kdc/kdc_util.h b/src/kdc/kdc_util.h
index e7bbf81134e319567f8a5181c9b26addaf83f880..5d8c8c2e82a5aa8c588dc387560ea1894340be7a 100644 (file)
--- a/src/kdc/kdc_util.h
+++ b/src/kdc/kdc_util.h
@@ -298,6 +298,30 @@ log_tgs_req(const krb5_fulladdr *from,
            const char *status, krb5_error_code errcode, const char *emsg);
 void log_tgs_alt_tgt(krb5_principal p);
 
+/*Request state*/
+
+struct kdc_request_state {
+    krb5_keyblock *armor_key;
+    krb5_pa_data *cookie;
+    krb5_int32 fast_options;
+    krb5_int32 fast_internal_flags;
+};
+krb5_error_code kdc_make_rstate(struct kdc_request_state **out);
+void kdc_free_rstate
+(struct kdc_request_state *s);
+
+/* FAST*/
+enum krb5_fast_kdc_flags {
+    KRB5_FAST_REPLY_KEY_USED = 0x1,
+    KRB5_FAST_REPLY_KEY_REPLACED = 0x02,
+};
+
+krb5_error_code  kdc_find_fast
+(krb5_kdc_req **requestptr,  krb5_data *checksummed_data,
+ krb5_keyblock *tgs_subkey,
+ struct kdc_request_state *state);
+
+ 
 
 
 #define isflagset(flagfield, flag) (flagfield & (flag))

diff --git a/src/lib/krb5/libkrb5.exports b/src/lib/krb5/libkrb5.exports
index c41d2e811bef3e4c62402a59ff30abda9cd1fa2c..f83ada839ebcba99bd67cbd973386926f00eda22 100644 (file)
--- a/src/lib/krb5/libkrb5.exports
+++ b/src/lib/krb5/libkrb5.exports
@@ -19,6 +19,7 @@ decode_krb5_encryption_key
 decode_krb5_error
 decode_krb5_etype_info
 decode_krb5_etype_info2
+decode_krb5_fast_req
 decode_krb5_kdc_req_body
 decode_krb5_pa_enc_ts
 decode_krb5_pa_for_user