gssapi: Import elric1's gss-token

This commit is contained in:
Nicolas Williams
2019-11-18 15:54:39 -06:00
parent 56c5f5909e
commit c1841f2f67
3 changed files with 645 additions and 2 deletions

View File

@@ -235,7 +235,7 @@ libgssapi_la_LIBADD = \
$(LIB_hcrypto) \
$(LIBADD_roken)
man_MANS = gssapi.3 gss_acquire_cred.3 mech/mech.5
man_MANS = gssapi.3 gss_acquire_cred.3 mech/mech.5 gss-token.1
include_HEADERS = gssapi.h
noinst_HEADERS = \
@@ -311,7 +311,7 @@ test_cfx_SOURCES = krb5/test_cfx.c
check_PROGRAMS = test_acquire_cred $(TESTS)
bin_PROGRAMS = gsstool
bin_PROGRAMS = gsstool gss-token
noinst_PROGRAMS = test_cred test_kcred test_context test_ntlm test_add_store_cred
test_context_SOURCES = test_context.c test_common.c test_common.h
@@ -332,6 +332,7 @@ LDADD = libgssapi.la \
dist_gsstool_SOURCES = gsstool.c
nodist_gsstool_SOURCES = gss-commands.c gss-commands.h
dist_gss_token_SOURCES = gss-token.c
gsstool_LDADD = libgssapi.la \
$(top_builddir)/lib/sl/libsl.la \
@@ -339,6 +340,10 @@ gsstool_LDADD = libgssapi.la \
$(LIB_readline) \
$(LIB_roken)
gss_token_LDADD = libgssapi.la \
$(top_builddir)/lib/krb5/libkrb5.la \
$(LIB_roken)
gss-commands.c gss-commands.h: gss-commands.in
$(SLC) $(srcdir)/gss-commands.in

75
lib/gssapi/gss-token.1 Normal file
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@@ -0,0 +1,75 @@
.\"
.\"
.Dd May 12, 2014
.Os
.Dt GSS-TOKEN 1
.Sh NAME
.Nm gss-token
.Nd generate and consume base64 GSS tokens
.Sh SYNOPSIS
.Nm
.Op Fl DNn
.Op Fl c count
.Ar service@host
.Nm
.Fl r
.Op Fl MNln
.Op Fl C Ar ccache
.Op Fl c count
.Op Ar service@host
.Sh DESCRIPTION
.Nm
generates and consumes base64 encoded GSS tokens.
It is mostly useful for testing.
.Pp
.Nm
supports the following options:
.Bl -tag -width indentxxxx
.It Fl C Ar ccache
write an accepted delegated credential into
.Ar ccache .
This only makes sense if
.Fl r
is specified.
.It Fl D
delegate credentials.
This only makes sense as a client, that is when
.Fl r
is not specified.
.It Fl M
copy the default ccache to a MEMORY: ccache before each
separate write operation.
The default ccache will not pick up any obtained service
tickets.
If specified with
.Fl c ,
the cache will revert to its original state before each
new token is written.
This can be used to load test the KDC.
.It Fl N
prepend
.Dq Negotiate\
to generated tokens and expect it on consumed tokens.
.It Fl c Ar count
repeat the operation
.Ar count
times.
This is good for very basic benchmarking.
.It Fl l
loop infinitely in read mode.
This is to support a multiple round trip GSS mechanism.
.It Fl n
do not output the generated token.
.It Fl r
read a token rather than generate a token.
.El
.Pp
.Nm
takes one argument, a
.Ar host@service
specifier.
The argument is required when generating a token but is optional if
consuming (reading) a token.
.Sh SEE ALSO
.Xr gssapi 3 ,
.Xr kerberos 8 .

563
lib/gssapi/gss-token.c Normal file
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@@ -0,0 +1,563 @@
/* */
/*-
* Copyright (c) 1997-2011 Roland C. Dowdeswell
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer and
* dedication in the documentation and/or other materials provided
* with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <errno.h>
#ifdef __APPLE__
#include <malloc/malloc.h>
#else
#include <malloc.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gssapi/gssapi.h>
#include <gssapi/gssapi_krb5.h>
#include <krb5.h>
#include <base64.h>
#include <getarg.h>
#include <roken.h>
#include <vers.h>
#define GBAIL(x, _maj, _min) do { \
if (GSS_ERROR(_maj)) { \
char *the_gss_err; \
\
ret = 1; \
the_gss_err = gss_mk_err(_maj, _min, x); \
if (the_gss_err) \
fprintf(stderr, "%s\n", the_gss_err); \
else \
fprintf(stderr, "err making err\n"); \
free(the_gss_err); \
goto bail; \
} \
} while (0)
#define K5BAIL(x) do { \
kret = x; \
if (kret) { \
const char *k5err; \
\
k5err = krb5_get_error_message(kctx, kret); \
if (k5err) { \
fprintf(stderr, "%s in %s:%s\n", k5err, \
#x, __func__); \
krb5_free_error_message(kctx, k5err); \
} else { \
fprintf(stderr, "unknown error %d in " \
"%s:%s\n", kret, #x, __func__); \
} \
exit(1); /* XXXrcd: shouldn't exit */ \
} \
} while (0)
/*
* global variables
*/
int nflag = 0;
static char *
gss_mk_err(OM_uint32 maj_stat, OM_uint32 min_stat, const char *preamble)
{
gss_buffer_desc status;
OM_uint32 new_stat;
OM_uint32 cur_stat;
OM_uint32 msg_ctx = 0;
OM_uint32 ret;
int type;
size_t newlen;
char *str = NULL;
char *tmp = NULL;
cur_stat = maj_stat;
type = GSS_C_GSS_CODE;
for (;;) {
/*
* GSS_S_FAILURE produces a rather unhelpful message, so
* we skip straight to the mech specific error in this case.
*/
if (type == GSS_C_GSS_CODE && cur_stat == GSS_S_FAILURE) {
type = GSS_C_MECH_CODE;
cur_stat = min_stat;
}
ret = gss_display_status(&new_stat, cur_stat, type,
GSS_C_NO_OID, &msg_ctx, &status);
if (GSS_ERROR(ret))
return str; /* XXXrcd: hmmm, not quite?? */
if (str)
newlen = strlen(str);
else
newlen = strlen(preamble);
newlen += status.length + 3;
tmp = str;
str = malloc(newlen);
if (!str) {
gss_release_buffer(&new_stat, &status);
return tmp; /* XXXrcd: hmmm, not quite?? */
}
snprintf(str, newlen, "%s%s%.*s", tmp?tmp:preamble,
tmp?", ":": ", (int)status.length, (char *)status.value);
gss_release_buffer(&new_stat, &status);
free(tmp);
/*
* If we are finished processing for maj_stat, then
* move onto min_stat.
*/
if (msg_ctx == 0 && type == GSS_C_GSS_CODE && min_stat != 0) {
type = GSS_C_MECH_CODE;
cur_stat = min_stat;
continue;
}
if (msg_ctx == 0)
break;
}
return str;
}
static int
write_one_token(gss_name_t service, int delegate, int negotiate)
{
gss_ctx_id_t ctx = GSS_C_NO_CONTEXT;
gss_buffer_desc in;
gss_buffer_desc out;
OM_uint32 maj;
OM_uint32 min;
OM_uint32 flags = 0;
int ret = 0;
char *base64_output = NULL;
in.length = 0;
in.value = 0;
out.length = 0;
out.value = 0;
if (delegate)
flags |= GSS_C_DELEG_FLAG;
maj = gss_init_sec_context(&min, GSS_C_NO_CREDENTIAL, &ctx, service,
GSS_C_NO_OID, flags, 0, GSS_C_NO_CHANNEL_BINDINGS, &in, NULL, &out,
NULL, NULL);
GBAIL("gss_init_sec_context", maj, min);
if (rk_base64_encode(out.value, out.length, &base64_output) < 0) {
fprintf(stderr, "Out of memory.\n");
ret = 1;
goto bail;
}
if (!nflag)
printf("%s%s\n", negotiate?"Negotiate ":"", base64_output);
bail:
if (out.value)
gss_release_buffer(&min, &out);
if (ctx != GSS_C_NO_CONTEXT) {
/*
* XXXrcd: here we ignore the fact that we might have an
* output token as this program doesn't do terribly
* well in that case.
*/
gss_delete_sec_context(&min, &ctx, NULL);
}
free(base64_output);
return ret;
}
static krb5_error_code
copy_cache(krb5_context kctx, krb5_ccache from, krb5_ccache to)
{
krb5_error_code kret;
krb5_principal princ = NULL;
krb5_cc_cursor cursor;
krb5_creds cred;
K5BAIL(krb5_cc_get_principal(kctx, from, &princ));
K5BAIL(krb5_cc_initialize(kctx, to, princ));
K5BAIL(krb5_cc_start_seq_get(kctx, from, &cursor));
for (;;) {
kret = krb5_cc_next_cred(kctx, from, &cursor, &cred);
if (kret)
break;
kret = krb5_cc_store_cred(kctx, to, &cred);
krb5_free_cred_contents(kctx, &cred);
if (kret)
break;
}
krb5_cc_end_seq_get(kctx, from, &cursor);
if (kret == KRB5_CC_END)
kret = 0;
K5BAIL(kret);
if (princ)
krb5_free_principal(kctx, princ);
return kret;
}
static int
write_token(gss_name_t service, int delegate, int negotiate, int memcache,
size_t count)
{
krb5_error_code kret;
krb5_context kctx = NULL;
krb5_ccache def_cache = NULL;
krb5_ccache mem_cache = NULL;
size_t i;
if (memcache) {
K5BAIL(krb5_init_context(&kctx));
K5BAIL(krb5_cc_default(kctx, &def_cache));
K5BAIL(krb5_cc_resolve(kctx, "MEMORY:mem_cache", &mem_cache));
putenv("KRB5CCNAME=MEMORY:mem_cache");
}
for (i=0; i < count; i++) {
if (memcache)
K5BAIL(copy_cache(kctx, def_cache, mem_cache));
kret = write_one_token(service, delegate, negotiate);
if (!nflag && i < count - 1)
printf("\n");
}
if (kctx)
krb5_free_context(kctx);
if (def_cache)
krb5_cc_close(kctx, def_cache);
if (mem_cache)
krb5_cc_close(kctx, mem_cache);
return kret;
}
static char *
read_buffer(FILE *fp)
{
char buf[65536];
char *p;
char *ret = NULL;
size_t buflen;
size_t retlen = 0;
while (fgets(buf, sizeof(buf), fp) != NULL) {
if ((p = strchr(buf, '\n')) == NULL) {
fprintf(stderr, "Long line, exiting.\n");
exit(1);
}
*p = '\0';
buflen = strlen(buf);
if (buflen == 0)
break;
ret = realloc(ret, retlen + buflen + 1);
memcpy(ret + retlen, buf, buflen);
ret[retlen + buflen] = '\0';
}
if (ferror(stdin)) {
perror("fgets");
exit(1);
}
return ret;
}
static int
read_one_token(gss_name_t service, const char *ccname, int negotiate)
{
gss_cred_id_t cred = NULL;
gss_cred_id_t deleg_creds = NULL;
gss_name_t client;
gss_OID mech_oid;
gss_ctx_id_t ctx = GSS_C_NO_CONTEXT;
gss_buffer_desc in = GSS_C_EMPTY_BUFFER;
gss_buffer_desc out, dname;
krb5_context kctx = NULL;
krb5_ccache ccache = NULL;
krb5_error_code kret;
OM_uint32 maj, min;
size_t len;
char *inbuf = NULL;
char *tmp;
int ret = 0;
if (service) {
maj = gss_acquire_cred(&min, service, 0, NULL, GSS_C_ACCEPT,
&cred, NULL, NULL);
GBAIL("gss_acquire_cred", maj, min);
}
inbuf = read_buffer(stdin);
if (!inbuf)
/* Just a couple of \n's in a row or EOF, not an error. */
return 0;
tmp = inbuf;
if (negotiate) {
if (strncasecmp("Negotiate ", inbuf, 10)) {
fprintf(stderr, "Token doesn't begin with "
"\"Negotiate \"\n");
return -1;
}
tmp += 10;
}
len = strlen(tmp);
in.value = malloc(len + 1);
if (!in.value) {
fprintf(stderr, "Out of memory.\n");
return -1;
}
ret = rk_base64_decode(tmp, in.value);
if (ret < 0) {
free(in.value);
if (errno == EOVERFLOW)
fprintf(stderr, "Token is too big\n");
else
fprintf(stderr, "Token encoding is not valid base64\n");
return -1;
}
out.length = 0;
out.value = 0;
maj = gss_accept_sec_context(&min, &ctx, cred, &in,
GSS_C_NO_CHANNEL_BINDINGS, &client, &mech_oid, &out,
NULL, NULL, &deleg_creds);
GBAIL("gss_accept_sec_context", maj, min);
/*
* XXXrcd: not bothering to clean up because we're about to exit.
* Probably should fix this in case the code is used as
* an example by someone.
*/
maj = gss_display_name(&min, client, &dname, NULL);
GBAIL("gss_display_name", maj, min);
if (!nflag)
printf("Authenticated: %.*s\n", (int)dname.length,
(char *)dname.value);
if (ccname) {
#ifdef HAVE_GSS_STORE_CRED_INTO
gss_key_value_set_desc store;
gss_key_value_element_desc elem;
int overwrite_cred = 1;
int default_cred = 0;
elem.key = "ccache";
elem.value = ccname;
store.count = 1;
store.elements = &elem;
maj = gss_store_cred_into(&min, deleg_creds, GSS_C_INITIATE,
GSS_C_NO_OID, overwrite_cred, default_cred, &store, NULL,
NULL);
GBAIL("gss_store_cred_into", maj, min);
#else
K5BAIL(krb5_init_context(&kctx));
K5BAIL(krb5_cc_resolve(kctx, ccname, &ccache));
maj = gss_krb5_copy_ccache(&min, deleg_creds, ccache);
GBAIL("gss_krb5_copy_ccache", maj, min);
#endif
}
bail:
if (kctx)
krb5_free_context(kctx);
if (ccache)
krb5_cc_close(kctx, ccache);
if (cred)
gss_release_cred(&min, &cred);
if (deleg_creds)
gss_release_cred(&min, &deleg_creds);
free(in.value);
free(inbuf);
return ret;
}
static int
read_token(gss_name_t service, const char *ccname, int negotiate, size_t count)
{
size_t i;
int ret;
for (i=0; i < count; i++) {
ret = read_one_token(service, ccname, negotiate);
}
return ret;
}
static gss_name_t
import_service(char *service)
{
gss_buffer_desc name;
gss_name_t svc = NULL;
OM_uint32 maj;
OM_uint32 min;
int ret = 0;
name.length = strlen(service);
name.value = service;
maj = gss_import_name(&min, &name, GSS_C_NT_HOSTBASED_SERVICE, &svc);
GBAIL("gss_import_name", maj, min);
bail:
if (ret)
exit(1);
return svc;
}
static void
usage(int ecode)
{
FILE *f = ecode == 0 ? stdout : stderr;
fprintf(f, "Usage: gss-token [-DNn] [-c count] service@host\n");
fprintf(f, " gss-token -r [-Nln] [-C ccache] [-c count] "
"[service@host]\n");
exit(ecode);
}
int
main(int argc, char **argv)
{
OM_uint32 min;
gss_name_t service = NULL;
size_t count = 1;
int Dflag = 0;
int Mflag = 0;
int Nflag = 0;
int hflag = 0;
int lflag = 0;
int rflag = 0;
int version_flag = 0;
int ret = 0;
int optidx = 0;
char *ccname = NULL;
struct getargs args[] = {
{ "help", 'h', arg_flag, &hflag, NULL, NULL },
{ "version", 0, arg_flag, &version_flag, NULL, NULL },
{ NULL, 'C', arg_string, &ccname, NULL, NULL },
{ NULL, 'D', arg_flag, &Dflag, NULL, NULL },
{ NULL, 'M', arg_flag, &Mflag, NULL, NULL },
{ NULL, 'N', arg_flag, &Nflag, NULL, NULL },
{ NULL, 'r', arg_flag, &rflag, NULL, NULL },
{ NULL, 'l', arg_flag, &lflag, NULL, NULL },
};
setprogname(argv[0]);
if (argc == 1 ||
getarg(args, sizeof(args)/sizeof(args[0]), argc, argv, &optidx))
usage(1);
if (hflag)
usage(0);
if (version_flag) {
print_version(NULL);
return 0;
}
argc -= optidx;
argv += optidx;
if (argc > 0)
service = import_service(*argv);
if (!rflag) {
if (!argc) {
fprintf(stderr, "Without -r, hostbased_service must "
"be provided.\n");
usage(1);
}
if (ccname) {
fprintf(stderr, "Specifying a target ccache doesn't "
"make sense without -r.\n");
usage(1);
}
ret = write_token(service, Dflag, Nflag, Mflag, count);
goto done;
}
if (Dflag) {
fprintf(stderr, "Delegating credentials (-D) doesn't make "
"sense when reading tokens (-r).\n");
usage(1);
}
do {
ret = read_token(service, ccname, Nflag, count);
} while (lflag && !ret && !feof(stdin));
done:
if (service)
gss_release_name(&min, &service);
return ret;
}