Use built-in modules for encrypted timestamp

Break out the encrypted timestamp code from kdc_preauth.c and
preauth2.c into built-in modules, allowing admins to disable it and
reducing the size of the framework code.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@25319 dc483132-0cff-0310-8789-dd5450dbe970

4 files changed, 147 insertions, 80 deletions

diff --git a/src/lib/krb5/krb/Makefile.in b/src/lib/krb5/krb/Makefile.in
index ddef9e29a..fe55c24ee 100644
--- a/src/lib/krb5/krb/Makefile.in
+++ b/src/lib/krb5/krb/Makefile.in
@@ -78,6 +78,7 @@ STLIBOBJS= \
 	pr_to_salt.o	\
 	preauth2.o	\
 	preauth_ec.o	\
+	preauth_encts.o	\
 	gic_opt_set_pa.o	\
 	princ_comp.o	\
 	privsafe.o	\
@@ -182,6 +183,7 @@ OBJS=	$(OUTPRE)addr_comp.$(OBJEXT)	\
 	$(OUTPRE)pr_to_salt.$(OBJEXT)	\
 	$(OUTPRE)preauth2.$(OBJEXT)	\
 	$(OUTPRE)preauth_ec.$(OBJEXT)	\
+	$(OUTPRE)preauth_encts.$(OBJEXT)	\
 	$(OUTPRE)gic_opt_set_pa.$(OBJEXT)	\
 	$(OUTPRE)princ_comp.$(OBJEXT)	\
 	$(OUTPRE)privsafe.$(OBJEXT)	\
@@ -286,6 +288,7 @@ SRCS=	$(srcdir)/addr_comp.c	\
 	$(srcdir)/pr_to_salt.c	\
 	$(srcdir)/preauth2.c	\
 	$(srcdir)/preauth_ec.c	\
+	$(srcdir)/preauth_encts.c	\
 	$(srcdir)/gic_opt_set_pa.c	\
 	$(srcdir)/princ_comp.c	\
 	$(srcdir)/privsafe.c	\
diff --git a/src/lib/krb5/krb/int-proto.h b/src/lib/krb5/krb/int-proto.h
index 7aebdb162..4e2d1deb2 100644
--- a/src/lib/krb5/krb/int-proto.h
+++ b/src/lib/krb5/krb/int-proto.h
@@ -58,6 +58,10 @@ clpreauth_encrypted_challenge_initvt(krb5_context context, int maj_ver,
                                      int min_ver, krb5_plugin_vtable vtable);
 
 krb5_error_code
+clpreauth_encrypted_timestamp_initvt(krb5_context context, int maj_ver,
+                                     int min_ver, krb5_plugin_vtable vtable);
+
+krb5_error_code
 krb5int_construct_matching_creds(krb5_context context, krb5_flags options,
                                  krb5_creds *in_creds, krb5_creds *mcreds,
                                  krb5_flags *fields);
diff --git a/src/lib/krb5/krb/preauth2.c b/src/lib/krb5/krb/preauth2.c
index 8c43938ef..f2ead9361 100644
--- a/src/lib/krb5/krb/preauth2.c
+++ b/src/lib/krb5/krb/preauth2.c
@@ -120,12 +120,15 @@ krb5_init_preauth_context(krb5_context kcontext)
     if (kcontext->preauth_context != NULL)
         return;
 
-    /* Auto-register encrypted challenge and (if possible) pkinit. */
+    /* Auto-register built-in modules. */
     k5_plugin_register_dyn(kcontext, PLUGIN_INTERFACE_CLPREAUTH, "pkinit",
                            "preauth");
     k5_plugin_register(kcontext, PLUGIN_INTERFACE_CLPREAUTH,
                        "encrypted_challenge",
                        clpreauth_encrypted_challenge_initvt);
+    k5_plugin_register(kcontext, PLUGIN_INTERFACE_CLPREAUTH,
+                       "encrypted_timestamp",
+                       clpreauth_encrypted_timestamp_initvt);
 
     /* Get all available clpreauth vtables. */
     if (k5_plugin_load_all(kcontext, PLUGIN_INTERFACE_CLPREAUTH, &plugins))
@@ -561,80 +564,6 @@ pa_fx_cookie(krb5_context context, krb5_kdc_req *request,
     return 0;
 }
 
-static krb5_error_code
-pa_enc_timestamp(krb5_context context, krb5_kdc_req *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 ret;
-    krb5_pa_enc_ts pa_enc;
-    krb5_data *tmp;
-    krb5_enc_data enc_data;
-    krb5_pa_data *pa;
-
-    if (as_key->length == 0) {
-#ifdef DEBUG
-        fprintf (stderr, "%s:%d: salt len=%d", __FILE__, __LINE__,
-                 salt->length);
-        if ((int) salt->length > 0)
-            fprintf (stderr, " '%.*s'", salt->length, salt->data);
-        fprintf (stderr, "; *etype=%d request->ktype[0]=%d\n",
-                 *etype, request->ktype[0]);
-#endif
-        if ((ret = ((*gak_fct)(context, request->client,
-                               *etype ? *etype : request->ktype[0],
-                               prompter, prompter_data,
-                               salt, s2kparams, as_key, gak_data))))
-            return(ret);
-        TRACE_PREAUTH_ENC_TS_KEY_GAK(context, as_key);
-    }
-
-    /* now get the time of day, and encrypt it accordingly */
-
-    if ((ret = krb5_us_timeofday(context, &pa_enc.patimestamp, &pa_enc.pausec)))
-        return(ret);
-
-    if ((ret = encode_krb5_pa_enc_ts(&pa_enc, &tmp)))
-        return(ret);
-
-    ret = krb5_encrypt_helper(context, as_key,
-                              KRB5_KEYUSAGE_AS_REQ_PA_ENC_TS,
-                              tmp, &enc_data);
-    TRACE_PREAUTH_ENC_TS(context, pa_enc.patimestamp, pa_enc.pausec,
-                         tmp, &enc_data.ciphertext);
-
-    krb5_free_data(context, tmp);
-
-    if (ret)
-        return(ret);
-
-    ret = encode_krb5_enc_data(&enc_data, &tmp);
-
-    free(enc_data.ciphertext.data);
-
-    if (ret)
-        return(ret);
-
-    if ((pa = (krb5_pa_data *) malloc(sizeof(krb5_pa_data))) == NULL) {
-        krb5_free_data(context, tmp);
-        return(ENOMEM);
-    }
-
-    pa->magic = KV5M_PA_DATA;
-    pa->pa_type = KRB5_PADATA_ENC_TIMESTAMP;
-    pa->length = tmp->length;
-    pa->contents = (krb5_octet *) tmp->data;
-
-    *out_padata = pa;
-
-    free(tmp);
-
-    return(0);
-}
-
 #if APPLE_PKINIT
 /*
  * PKINIT. One function to generate AS-REQ, one to parse AS-REP
@@ -1387,11 +1316,6 @@ static const pa_types_t pa_types[] = {
     },
 #endif /* APPLE_PKINIT */
     {
-        KRB5_PADATA_ENC_TIMESTAMP,
-        pa_enc_timestamp,
-        PA_REAL,
-    },
-    {
         KRB5_PADATA_SAM_CHALLENGE_2,
         pa_sam_2,
         PA_REAL,
diff --git a/src/lib/krb5/krb/preauth_encts.c b/src/lib/krb5/krb/preauth_encts.c
new file mode 100644
index 000000000..6e3268603
--- /dev/null
+++ b/src/lib/krb5/krb/preauth_encts.c
@@ -0,0 +1,136 @@
+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/* lib/krb5/krb/preauth_encts.c - Encrypted timestamp clpreauth module */
+/*
+ * Copyright 1995, 2003, 2008, 2011 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 <krb5/preauth_plugin.h>
+#include "int-proto.h"
+
+static int
+encts_flags(krb5_context context, krb5_preauthtype pa_type)
+{
+    return PA_REAL;
+}
+
+static krb5_error_code
+encts_process(krb5_context context, krb5_clpreauth_moddata moddata,
+              krb5_clpreauth_modreq modreq, krb5_get_init_creds_opt *opt,
+              krb5_clpreauth_callbacks cb, krb5_clpreauth_rock rock,
+              krb5_kdc_req *request, krb5_data *encoded_request_body,
+              krb5_data *encoded_previous_request, krb5_pa_data *padata,
+              krb5_prompter_fct prompter, void *prompter_data,
+              krb5_clpreauth_get_as_key_fn gak_fct, void *gak_data,
+              krb5_data *salt, krb5_data *s2kparams, krb5_keyblock *as_key,
+              krb5_pa_data ***out_padata)
+{
+    krb5_error_code ret;
+    krb5_pa_enc_ts pa_enc;
+    krb5_data *ts = NULL, *enc_ts = NULL;
+    krb5_enc_data enc_data;
+    krb5_pa_data **pa = NULL;
+    krb5_enctype etype = cb->get_etype(context, rock);
+
+    enc_data.ciphertext = empty_data();
+
+    if (as_key->length == 0) {
+#ifdef DEBUG
+        fprintf (stderr, "%s:%d: salt len=%d", __FILE__, __LINE__,
+                 salt->length);
+        if ((int) salt->length > 0)
+            fprintf (stderr, " '%.*s'", salt->length, salt->data);
+        fprintf (stderr, "; *etype=%d request->ktype[0]=%d\n",
+                 etype, request->ktype[0]);
+#endif
+        ret = (*gak_fct)(context, request->client, etype, prompter,
+                         prompter_data, salt, s2kparams, as_key, gak_data);
+        if (ret)
+            goto cleanup;
+        TRACE_PREAUTH_ENC_TS_KEY_GAK(context, as_key);
+    }
+
+    /* now get the time of day, and encrypt it accordingly */
+    ret = krb5_us_timeofday(context, &pa_enc.patimestamp, &pa_enc.pausec);
+    if (ret)
+        goto cleanup;
+
+    ret = encode_krb5_pa_enc_ts(&pa_enc, &ts);
+    if (ret)
+        goto cleanup;
+
+    ret = krb5_encrypt_helper(context, as_key, KRB5_KEYUSAGE_AS_REQ_PA_ENC_TS,
+                              ts, &enc_data);
+    if (ret)
+        goto cleanup;
+    TRACE_PREAUTH_ENC_TS(context, pa_enc.patimestamp, pa_enc.pausec,
+                         ts, &enc_data.ciphertext);
+
+    ret = encode_krb5_enc_data(&enc_data, &enc_ts);
+    if (ret)
+        goto cleanup;
+
+    pa = k5alloc(2 * sizeof(krb5_pa_data *), &ret);
+    if (pa == NULL)
+        goto cleanup;
+
+    pa[0] = k5alloc(sizeof(krb5_pa_data), &ret);
+    if (pa[0] == NULL)
+        goto cleanup;
+
+    pa[0]->magic = KV5M_PA_DATA;
+    pa[0]->pa_type = KRB5_PADATA_ENC_TIMESTAMP;
+    pa[0]->length = enc_ts->length;
+    pa[0]->contents = (krb5_octet *) enc_ts->data;
+    enc_ts->data = NULL;
+    pa[1] = NULL;
+    *out_padata = pa;
+    pa = NULL;
+
+cleanup:
+    krb5_free_data(context, ts);
+    krb5_free_data(context, enc_ts);
+    free(enc_data.ciphertext.data);
+    free(pa);
+    return ret;
+}
+
+static krb5_preauthtype encts_pa_types[] = {
+    KRB5_PADATA_ENC_TIMESTAMP, 0};
+
+krb5_error_code
+clpreauth_encrypted_timestamp_initvt(krb5_context context, int maj_ver,
+                                     int min_ver, krb5_plugin_vtable vtable)
+{
+    krb5_clpreauth_vtable vt;
+
+    if (maj_ver != 1)
+        return KRB5_PLUGIN_VER_NOTSUPP;
+    vt = (krb5_clpreauth_vtable)vtable;
+    vt->name = "encrypted_timestamp";
+    vt->pa_type_list = encts_pa_types;
+    vt->flags = encts_flags;
+    vt->process = encts_process;
+    return 0;
+}