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|
/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/krb5/krb/preauth_otp.c - OTP clpreauth module */
/*
* Copyright 2011 NORDUnet A/S. All rights reserved.
* Copyright 2011 Red Hat, Inc. 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 in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER
* OR CONTRIBUTORS 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 "k5-int.h"
#include "k5-json.h"
#include "int-proto.h"
#include <krb5/clpreauth_plugin.h>
#include <ctype.h>
static krb5_preauthtype otp_client_supported_pa_types[] =
{ KRB5_PADATA_OTP_CHALLENGE, 0 };
/* Frees a tokeninfo. */
static void
free_tokeninfo(krb5_responder_otp_tokeninfo *ti)
{
if (ti == NULL)
return;
free(ti->alg_id);
free(ti->challenge);
free(ti->token_id);
free(ti->vendor);
free(ti);
}
/* Converts a property of a json object into a char*. */
static krb5_error_code
codec_value_to_string(k5_json_object obj, const char *key, char **string)
{
k5_json_value val;
char *str;
val = k5_json_object_get(obj, key);
if (val == NULL)
return ENOENT;
if (k5_json_get_tid(val) != K5_JSON_TID_STRING)
return EINVAL;
str = strdup(k5_json_string_utf8(val));
if (str == NULL)
return ENOMEM;
*string = str;
return 0;
}
/* Converts a property of a json object into a krb5_data struct. */
static krb5_error_code
codec_value_to_data(k5_json_object obj, const char *key, krb5_data *data)
{
krb5_error_code retval;
char *tmp;
retval = codec_value_to_string(obj, key, &tmp);
if (retval != 0)
return retval;
*data = string2data(tmp);
return 0;
}
/* Converts a krb5_data struct into a property of a JSON object. */
static krb5_error_code
codec_data_to_value(krb5_data *data, k5_json_object obj, const char *key)
{
krb5_error_code retval;
k5_json_string str;
if (data->data == NULL)
return 0;
retval = k5_json_string_create_len(data->data, data->length, &str);
if (retval)
return retval;
retval = k5_json_object_set(obj, key, str);
k5_json_release(str);
return retval;
}
/* Converts a property of a json object into a krb5_int32. */
static krb5_error_code
codec_value_to_int32(k5_json_object obj, const char *key, krb5_int32 *int32)
{
k5_json_value val;
val = k5_json_object_get(obj, key);
if (val == NULL)
return ENOENT;
if (k5_json_get_tid(val) != K5_JSON_TID_NUMBER)
return EINVAL;
*int32 = k5_json_number_value(val);
return 0;
}
/* Converts a krb5_int32 into a property of a JSON object. */
static krb5_error_code
codec_int32_to_value(krb5_int32 int32, k5_json_object obj, const char *key)
{
krb5_error_code retval;
k5_json_number num;
if (int32 == -1)
return 0;
retval = k5_json_number_create(int32, &num);
if (retval)
return retval;
retval = k5_json_object_set(obj, key, num);
k5_json_release(num);
return retval;
}
/* Converts a krb5_otp_tokeninfo into a JSON object. */
static krb5_error_code
codec_encode_tokeninfo(krb5_otp_tokeninfo *ti, k5_json_object *out)
{
krb5_error_code retval;
k5_json_object obj;
krb5_flags flags;
retval = k5_json_object_create(&obj);
if (retval != 0)
goto error;
flags = KRB5_RESPONDER_OTP_FLAGS_COLLECT_TOKEN;
if (ti->flags & KRB5_OTP_FLAG_COLLECT_PIN) {
flags |= KRB5_RESPONDER_OTP_FLAGS_COLLECT_PIN;
if (ti->flags & KRB5_OTP_FLAG_SEPARATE_PIN)
flags |= KRB5_RESPONDER_OTP_FLAGS_NEXTOTP;
}
if (ti->flags & KRB5_OTP_FLAG_NEXTOTP)
flags |= KRB5_RESPONDER_OTP_FLAGS_NEXTOTP;
retval = codec_int32_to_value(flags, obj, "flags");
if (retval != 0)
goto error;
retval = codec_data_to_value(&ti->vendor, obj, "vendor");
if (retval != 0)
goto error;
retval = codec_data_to_value(&ti->challenge, obj, "challenge");
if (retval != 0)
goto error;
retval = codec_int32_to_value(ti->length, obj, "length");
if (retval != 0)
goto error;
if (ti->format != KRB5_OTP_FORMAT_BASE64 &&
ti->format != KRB5_OTP_FORMAT_BINARY) {
retval = codec_int32_to_value(ti->format, obj, "format");
if (retval != 0)
goto error;
}
retval = codec_data_to_value(&ti->token_id, obj, "tokenID");
if (retval != 0)
goto error;
retval = codec_data_to_value(&ti->alg_id, obj, "algID");
if (retval != 0)
goto error;
*out = obj;
return 0;
error:
k5_json_release(obj);
return retval;
}
/* Converts a krb5_pa_otp_challenge into a JSON object. */
static krb5_error_code
codec_encode_challenge(krb5_context ctx, krb5_pa_otp_challenge *chl,
char **json)
{
k5_json_object obj = NULL, tmp = NULL;
k5_json_string str = NULL;
k5_json_array arr = NULL;
krb5_error_code retval;
int i;
retval = k5_json_object_create(&obj);
if (retval != 0)
goto cleanup;
if (chl->service.data) {
retval = k5_json_string_create_len(chl->service.data,
chl->service.length, &str);
if (retval != 0)
goto cleanup;
retval = k5_json_object_set(obj, "service", str);
k5_json_release(str);
if (retval != 0)
goto cleanup;
}
retval = k5_json_array_create(&arr);
if (retval != 0)
goto cleanup;
for (i = 0; chl->tokeninfo[i] != NULL ; i++) {
retval = codec_encode_tokeninfo(chl->tokeninfo[i], &tmp);
if (retval != 0)
goto cleanup;
retval = k5_json_array_add(arr, tmp);
k5_json_release(tmp);
if (retval != 0)
goto cleanup;
}
retval = k5_json_object_set(obj, "tokenInfo", arr);
if (retval != 0)
goto cleanup;
retval = k5_json_encode(obj, json);
if (retval)
goto cleanup;
cleanup:
k5_json_release(arr);
k5_json_release(obj);
return retval;
}
/* Converts a JSON object into a krb5_responder_otp_tokeninfo. */
static krb5_responder_otp_tokeninfo *
codec_decode_tokeninfo(k5_json_object obj)
{
krb5_responder_otp_tokeninfo *ti = NULL;
krb5_error_code retval;
ti = calloc(1, sizeof(krb5_responder_otp_tokeninfo));
if (ti == NULL)
goto error;
retval = codec_value_to_int32(obj, "flags", &ti->flags);
if (retval != 0)
goto error;
retval = codec_value_to_string(obj, "vendor", &ti->vendor);
if (retval != 0 && retval != ENOENT)
goto error;
retval = codec_value_to_string(obj, "challenge", &ti->challenge);
if (retval != 0 && retval != ENOENT)
goto error;
retval = codec_value_to_int32(obj, "length", &ti->length);
if (retval == ENOENT)
ti->length = -1;
else if (retval != 0)
goto error;
retval = codec_value_to_int32(obj, "format", &ti->format);
if (retval == ENOENT)
ti->format = -1;
else if (retval != 0)
goto error;
retval = codec_value_to_string(obj, "tokenID", &ti->token_id);
if (retval != 0 && retval != ENOENT)
goto error;
retval = codec_value_to_string(obj, "algID", &ti->alg_id);
if (retval != 0 && retval != ENOENT)
goto error;
return ti;
error:
free_tokeninfo(ti);
return NULL;
}
/* Converts a JSON object into a krb5_responder_otp_challenge. */
static krb5_responder_otp_challenge *
codec_decode_challenge(krb5_context ctx, const char *json)
{
krb5_responder_otp_challenge *chl = NULL;
k5_json_value obj = NULL, arr = NULL, tmp = NULL;
krb5_error_code retval;
size_t i;
retval = k5_json_decode(json, &obj);
if (retval != 0)
goto error;
if (k5_json_get_tid(obj) != K5_JSON_TID_OBJECT)
goto error;
arr = k5_json_object_get(obj, "tokenInfo");
if (arr == NULL)
goto error;
if (k5_json_get_tid(arr) != K5_JSON_TID_ARRAY)
goto error;
chl = calloc(1, sizeof(krb5_responder_otp_challenge));
if (chl == NULL)
goto error;
chl->tokeninfo = calloc(k5_json_array_length(arr) + 1,
sizeof(krb5_responder_otp_tokeninfo*));
if (chl->tokeninfo == NULL)
goto error;
retval = codec_value_to_string(obj, "service", &chl->service);
if (retval != 0 && retval != ENOENT)
goto error;
for (i = 0; i < k5_json_array_length(arr); i++) {
tmp = k5_json_array_get(arr, i);
if (k5_json_get_tid(tmp) != K5_JSON_TID_OBJECT)
goto error;
chl->tokeninfo[i] = codec_decode_tokeninfo(tmp);
if (chl->tokeninfo[i] == NULL)
goto error;
}
k5_json_release(obj);
return chl;
error:
if (chl != NULL) {
for (i = 0; chl->tokeninfo != NULL && chl->tokeninfo[i] != NULL; i++)
free_tokeninfo(chl->tokeninfo[i]);
free(chl->tokeninfo);
free(chl);
}
k5_json_release(obj);
return NULL;
}
/* Decode the responder answer into a tokeninfo, a value and a pin. */
static krb5_error_code
codec_decode_answer(krb5_context context, const char *answer,
krb5_otp_tokeninfo **tis, krb5_otp_tokeninfo **ti,
krb5_data *value, krb5_data *pin)
{
krb5_error_code retval;
k5_json_value val = NULL;
krb5_int32 indx, i;
krb5_data tmp;
if (answer == NULL)
return EBADMSG;
retval = k5_json_decode(answer, &val);
if (retval != 0)
goto cleanup;
if (k5_json_get_tid(val) != K5_JSON_TID_OBJECT)
goto cleanup;
retval = codec_value_to_int32(val, "tokeninfo", &indx);
if (retval != 0)
goto cleanup;
for (i = 0; tis[i] != NULL; i++) {
if (i == indx) {
retval = codec_value_to_data(val, "value", &tmp);
if (retval != 0 && retval != ENOENT)
goto cleanup;
retval = codec_value_to_data(val, "pin", pin);
if (retval != 0 && retval != ENOENT) {
krb5_free_data_contents(context, &tmp);
goto cleanup;
}
*value = tmp;
*ti = tis[i];
retval = 0;
goto cleanup;
}
}
retval = EINVAL;
cleanup:
k5_json_release(val);
return retval;
}
/* Takes the nonce from the challenge and encrypts it into the request. */
static krb5_error_code
encrypt_nonce(krb5_context ctx, krb5_keyblock *key,
const krb5_pa_otp_challenge *chl, krb5_pa_otp_req *req)
{
krb5_error_code retval;
krb5_enc_data encdata;
krb5_data *er;
/* Encode the nonce. */
retval = encode_krb5_pa_otp_enc_req(&chl->nonce, &er);
if (retval != 0)
return retval;
/* Do the encryption. */
retval = krb5_encrypt_helper(ctx, key, KRB5_KEYUSAGE_PA_OTP_REQUEST,
er, &encdata);
krb5_free_data(ctx, er);
if (retval != 0)
return retval;
req->enc_data = encdata;
return 0;
}
/* Checks to see if the user-supplied otp value matches the length and format
* of the supplied tokeninfo. */
static int
otpvalue_matches_tokeninfo(const char *otpvalue, krb5_otp_tokeninfo *ti)
{
int (*table[])(int c) = { isdigit, isxdigit, isalnum };
if (otpvalue == NULL || ti == NULL)
return 0;
if (ti->length >= 0 && strlen(otpvalue) != (size_t)ti->length)
return 0;
if (ti->format >= 0 && ti->format < 3) {
while (*otpvalue) {
if (!(*table[ti->format])((unsigned char)*otpvalue++))
return 0;
}
}
return 1;
}
/* Performs a prompt and saves the response in the out parameter. */
static krb5_error_code
doprompt(krb5_context context, krb5_prompter_fct prompter, void *prompter_data,
const char *banner, const char *prompttxt, char *out, size_t len)
{
krb5_prompt prompt;
krb5_data prompt_reply;
krb5_error_code retval;
if (prompttxt == NULL || out == NULL)
return EINVAL;
memset(out, 0, len);
prompt_reply = make_data(out, len);
prompt.reply = &prompt_reply;
prompt.prompt = (char *)prompttxt;
prompt.hidden = 1;
retval = (*prompter)(context, prompter_data, NULL, banner, 1, &prompt);
if (retval != 0)
return retval;
return 0;
}
/* Forces the user to choose a single tokeninfo via prompting. */
static krb5_error_code
prompt_for_tokeninfo(krb5_context context, krb5_prompter_fct prompter,
void *prompter_data, krb5_otp_tokeninfo **tis,
krb5_otp_tokeninfo **out_ti)
{
char *banner = NULL, *tmp, response[1024];
krb5_otp_tokeninfo *ti = NULL;
krb5_error_code retval = 0;
int i = 0, j = 0;
for (i = 0; tis[i] != NULL; i++) {
if (asprintf(&tmp, "%s\t%d. %s %.*s\n",
banner ? banner :
_("Please choose from the following:\n"),
i + 1, _("Vendor:"), tis[i]->vendor.length,
tis[i]->vendor.data) < 0) {
free(banner);
return ENOMEM;
}
free(banner);
banner = tmp;
}
do {
retval = doprompt(context, prompter, prompter_data,
banner, _("Enter #"), response, sizeof(response));
if (retval != 0) {
free(banner);
return retval;
}
errno = 0;
j = strtol(response, NULL, 0);
if (errno != 0) {
free(banner);
return errno;
}
if (j < 1 || j > i)
continue;
ti = tis[--j];
} while (ti == NULL);
free(banner);
*out_ti = ti;
return 0;
}
/* Builds a challenge string from the given tokeninfo. */
static krb5_error_code
make_challenge(const krb5_otp_tokeninfo *ti, char **challenge)
{
if (challenge == NULL)
return EINVAL;
*challenge = NULL;
if (ti == NULL || ti->challenge.data == NULL)
return 0;
if (asprintf(challenge, "%s %.*s\n",
_("OTP Challenge:"),
ti->challenge.length,
ti->challenge.data) < 0)
return ENOMEM;
return 0;
}
/* Determines if a pin is required. If it is, it will be prompted for. */
static inline krb5_error_code
collect_pin(krb5_context context, krb5_prompter_fct prompter,
void *prompter_data, const krb5_otp_tokeninfo *ti,
krb5_data *out_pin)
{
krb5_error_code retval;
char otppin[1024];
krb5_flags collect;
krb5_data pin;
/* If no PIN will be collected, don't prompt. */
collect = ti->flags & (KRB5_OTP_FLAG_COLLECT_PIN |
KRB5_OTP_FLAG_SEPARATE_PIN);
if (collect == 0) {
*out_pin = empty_data();
return 0;
}
/* Collect the PIN. */
retval = doprompt(context, prompter, prompter_data, NULL,
_("OTP Token PIN"), otppin, sizeof(otppin));
if (retval != 0)
return retval;
/* Set the PIN. */
pin = make_data(strdup(otppin), strlen(otppin));
if (pin.data == NULL)
return ENOMEM;
*out_pin = pin;
return 0;
}
/* Builds a request using the specified tokeninfo, value and pin. */
static krb5_error_code
make_request(krb5_context ctx, krb5_otp_tokeninfo *ti, const krb5_data *value,
const krb5_data *pin, krb5_pa_otp_req **out_req)
{
krb5_pa_otp_req *req = NULL;
krb5_error_code retval = 0;
if (ti == NULL)
return 0;
if (ti->format == KRB5_OTP_FORMAT_BASE64)
return ENOTSUP;
req = calloc(1, sizeof(krb5_pa_otp_req));
if (req == NULL)
return ENOMEM;
req->flags = ti->flags & KRB5_OTP_FLAG_NEXTOTP;
retval = krb5int_copy_data_contents(ctx, &ti->vendor, &req->vendor);
if (retval != 0)
goto error;
req->format = ti->format;
retval = krb5int_copy_data_contents(ctx, &ti->token_id, &req->token_id);
if (retval != 0)
goto error;
retval = krb5int_copy_data_contents(ctx, &ti->alg_id, &req->alg_id);
if (retval != 0)
goto error;
retval = krb5int_copy_data_contents(ctx, value, &req->otp_value);
if (retval != 0)
goto error;
if (ti->flags & KRB5_OTP_FLAG_COLLECT_PIN) {
if (ti->flags & KRB5_OTP_FLAG_SEPARATE_PIN) {
if (pin == NULL || pin->data == NULL) {
retval = EINVAL; /* No pin found! */
goto error;
}
retval = krb5int_copy_data_contents(ctx, pin, &req->pin);
if (retval != 0)
goto error;
} else if (pin != NULL && pin->data != NULL) {
krb5_free_data_contents(ctx, &req->otp_value);
retval = asprintf(&req->otp_value.data, "%.*s%.*s",
pin->length, pin->data,
value->length, value->data);
if (retval < 0) {
retval = ENOMEM;
req->otp_value = empty_data();
goto error;
}
req->otp_value.length = req->pin.length + req->otp_value.length;
} /* Otherwise, the responder has already combined them. */
}
*out_req = req;
return 0;
error:
k5_free_pa_otp_req(ctx, req);
return retval;
}
/*
* Filters a set of tokeninfos given an otp value. If the set is reduced to
* a single tokeninfo, it will be set in out_ti. Otherwise, a new shallow copy
* will be allocated in out_filtered.
*/
static inline krb5_error_code
filter_tokeninfos(krb5_context context, const char *otpvalue,
krb5_otp_tokeninfo **tis,
krb5_otp_tokeninfo ***out_filtered,
krb5_otp_tokeninfo **out_ti)
{
krb5_otp_tokeninfo **filtered;
size_t i = 0, j = 0;
while (tis[i] != NULL)
i++;
filtered = calloc(i + 1, sizeof(const krb5_otp_tokeninfo *));
if (filtered == NULL)
return ENOMEM;
/* Make a list of tokeninfos that match the value. */
for (i = 0, j = 0; tis[i] != NULL; i++) {
if (otpvalue_matches_tokeninfo(otpvalue, tis[i]))
filtered[j++] = tis[i];
}
/* It is an error if we have no matching tokeninfos. */
if (filtered[0] == NULL) {
free(filtered);
k5_setmsg(context, KRB5_PREAUTH_FAILED,
_("OTP value doesn't match any token formats"));
return KRB5_PREAUTH_FAILED; /* We have no supported tokeninfos. */
}
/* Otherwise, if we have just one tokeninfo, choose it. */
if (filtered[1] == NULL) {
*out_ti = filtered[0];
*out_filtered = NULL;
free(filtered);
return 0;
}
/* Otherwise, we'll return the remaining list. */
*out_ti = NULL;
*out_filtered = filtered;
return 0;
}
/* Outputs the selected tokeninfo and possibly a value and pin.
* Prompting may occur. */
static krb5_error_code
prompt_for_token(krb5_context context, krb5_prompter_fct prompter,
void *prompter_data, krb5_otp_tokeninfo **tis,
krb5_otp_tokeninfo **out_ti, krb5_data *out_value,
krb5_data *out_pin)
{
krb5_otp_tokeninfo **filtered = NULL;
krb5_otp_tokeninfo *ti = NULL;
krb5_error_code retval;
int i, challengers = 0;
char *challenge = NULL;
char otpvalue[1024];
krb5_data value, pin;
memset(otpvalue, 0, sizeof(otpvalue));
if (tis == NULL || tis[0] == NULL || out_ti == NULL)
return EINVAL;
/* Count how many challenges we have. */
for (i = 0; tis[i] != NULL; i++) {
if (tis[i]->challenge.data != NULL)
challengers++;
}
/* If we have only one tokeninfo as input, choose it. */
if (i == 1)
ti = tis[0];
/* Setup our challenge, if present. */
if (challengers > 0) {
/* If we have multiple tokeninfos still, choose now. */
if (ti == NULL) {
retval = prompt_for_tokeninfo(context, prompter, prompter_data,
tis, &ti);
if (retval != 0)
return retval;
}
/* Create the challenge prompt. */
retval = make_challenge(ti, &challenge);
if (retval != 0)
return retval;
}
/* Prompt for token value. */
retval = doprompt(context, prompter, prompter_data, challenge,
_("Enter OTP Token Value"), otpvalue, sizeof(otpvalue));
free(challenge);
if (retval != 0)
return retval;
if (ti == NULL) {
/* Filter out tokeninfos that don't match our token value. */
retval = filter_tokeninfos(context, otpvalue, tis, &filtered, &ti);
if (retval != 0)
return retval;
/* If we still don't have a single tokeninfo, choose now. */
if (filtered != NULL) {
retval = prompt_for_tokeninfo(context, prompter, prompter_data,
filtered, &ti);
free(filtered);
if (retval != 0)
return retval;
}
}
assert(ti != NULL);
/* Set the value. */
value = make_data(strdup(otpvalue), strlen(otpvalue));
if (value.data == NULL)
return ENOMEM;
/* Collect the PIN, if necessary. */
retval = collect_pin(context, prompter, prompter_data, ti, &pin);
if (retval != 0) {
krb5_free_data_contents(context, &value);
return retval;
}
*out_value = value;
*out_pin = pin;
*out_ti = ti;
return 0;
}
/* Encode the OTP request into a krb5_pa_data buffer. */
static krb5_error_code
set_pa_data(const krb5_pa_otp_req *req, krb5_pa_data ***pa_data_out)
{
krb5_pa_data **out = NULL;
krb5_data *tmp;
/* Allocate the preauth data array and one item. */
out = calloc(2, sizeof(krb5_pa_data *));
if (out == NULL)
goto error;
out[0] = calloc(1, sizeof(krb5_pa_data));
out[1] = NULL;
if (out[0] == NULL)
goto error;
/* Encode our request into the preauth data item. */
memset(out[0], 0, sizeof(krb5_pa_data));
out[0]->pa_type = KRB5_PADATA_OTP_REQUEST;
if (encode_krb5_pa_otp_req(req, &tmp) != 0)
goto error;
out[0]->contents = (krb5_octet *)tmp->data;
out[0]->length = tmp->length;
free(tmp);
*pa_data_out = out;
return 0;
error:
if (out != NULL) {
free(out[0]);
free(out);
}
return ENOMEM;
}
/* Tests krb5_data to see if it is printable. */
static krb5_boolean
is_printable_string(const krb5_data *data)
{
unsigned int i;
if (data == NULL)
return FALSE;
for (i = 0; i < data->length; i++) {
if (!isprint((unsigned char)data->data[i]))
return FALSE;
}
return TRUE;
}
/* Returns TRUE when the given tokeninfo contains the subset of features we
* support. */
static krb5_boolean
is_tokeninfo_supported(krb5_otp_tokeninfo *ti)
{
krb5_flags supported_flags = KRB5_OTP_FLAG_COLLECT_PIN |
KRB5_OTP_FLAG_NO_COLLECT_PIN |
KRB5_OTP_FLAG_SEPARATE_PIN;
/* Flags we don't support... */
if (ti->flags & ~supported_flags)
return FALSE;
/* We don't currently support hashing. */
if (ti->supported_hash_alg != NULL || ti->iteration_count >= 0)
return FALSE;
/* Remove tokeninfos with invalid vendor strings. */
if (!is_printable_string(&ti->vendor))
return FALSE;
/* Remove tokeninfos with non-printable challenges. */
if (!is_printable_string(&ti->challenge))
return FALSE;
/* We don't currently support base64. */
if (ti->format == KRB5_OTP_FORMAT_BASE64)
return FALSE;
return TRUE;
}
/* Removes unsupported tokeninfos. Returns an error if no tokeninfos remain. */
static krb5_error_code
filter_supported_tokeninfos(krb5_context context, krb5_otp_tokeninfo **tis)
{
size_t i, j;
/* Filter out any tokeninfos we don't support. */
for (i = 0, j = 0; tis[i] != NULL; i++) {
if (!is_tokeninfo_supported(tis[i]))
k5_free_otp_tokeninfo(context, tis[i]);
else
tis[j++] = tis[i];
}
/* Terminate the array. */
tis[j] = NULL;
if (tis[0] != NULL)
return 0;
k5_setmsg(context, KRB5_PREAUTH_FAILED, _("No supported tokens"));
return KRB5_PREAUTH_FAILED; /* We have no supported tokeninfos. */
}
/*
* Try to find tokeninfos which match configuration data recorded in the input
* ccache, and if exactly one is found, drop the rest.
*/
static krb5_error_code
filter_config_tokeninfos(krb5_context context,
krb5_clpreauth_callbacks cb,
krb5_clpreauth_rock rock,
krb5_otp_tokeninfo **tis)
{
krb5_otp_tokeninfo *match = NULL;
size_t i, j;
const char *vendor, *alg_id, *token_id;
/* Pull up what we know about the token we want to use. */
vendor = cb->get_cc_config(context, rock, "vendor");
alg_id = cb->get_cc_config(context, rock, "algID");
token_id = cb->get_cc_config(context, rock, "tokenID");
/* Look for a single matching entry. */
for (i = 0; tis[i] != NULL; i++) {
if (vendor != NULL && tis[i]->vendor.length > 0 &&
!data_eq_string(tis[i]->vendor, vendor))
continue;
if (alg_id != NULL && tis[i]->alg_id.length > 0 &&
!data_eq_string(tis[i]->alg_id, alg_id))
continue;
if (token_id != NULL && tis[i]->token_id.length > 0 &&
!data_eq_string(tis[i]->token_id, token_id))
continue;
/* Oh, we already had a matching entry. More than one -> no change. */
if (match != NULL)
return 0;
match = tis[i];
}
/* No matching entry -> no change. */
if (match == NULL)
return 0;
/* Prune out everything except the best match. */
for (i = 0, j = 0; tis[i] != NULL; i++) {
if (tis[i] != match)
k5_free_otp_tokeninfo(context, tis[i]);
else
tis[j++] = tis[i];
}
tis[j] = NULL;
return 0;
}
static void
otp_client_request_init(krb5_context context, krb5_clpreauth_moddata moddata,
krb5_clpreauth_modreq *modreq_out)
{
*modreq_out = calloc(1, sizeof(krb5_pa_otp_challenge *));
}
static krb5_error_code
otp_client_prep_questions(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 *pa_data)
{
krb5_pa_otp_challenge *chl;
krb5_error_code retval;
krb5_data tmp;
char *json;
if (modreq == NULL)
return ENOMEM;
/* Decode the challenge. */
tmp = make_data(pa_data->contents, pa_data->length);
retval = decode_krb5_pa_otp_challenge(&tmp,
(krb5_pa_otp_challenge **)modreq);
if (retval != 0)
return retval;
chl = *(krb5_pa_otp_challenge **)modreq;
/* Remove unsupported tokeninfos. */
retval = filter_supported_tokeninfos(context, chl->tokeninfo);
if (retval != 0)
return retval;
/* Remove tokeninfos that don't match the recorded description, if that
* results in there being only one that does. */
retval = filter_config_tokeninfos(context, cb, rock, chl->tokeninfo);
if (retval != 0)
return retval;
/* Make the JSON representation. */
retval = codec_encode_challenge(context, chl, &json);
if (retval != 0)
return retval;
/* Ask the question. */
retval = cb->ask_responder_question(context, rock,
KRB5_RESPONDER_QUESTION_OTP,
json);
free(json);
return retval;
}
/*
* Save the vendor, algID, and tokenID values for the selected token to the
* out_ccache, so that later we can try to use them to select the right one
* without having ot ask the user.
*/
static void
save_config_tokeninfo(krb5_context context,
krb5_clpreauth_callbacks cb,
krb5_clpreauth_rock rock,
krb5_otp_tokeninfo *ti)
{
char *tmp;
if (ti->vendor.length > 0 &&
asprintf(&tmp, "%.*s", ti->vendor.length, ti->vendor.data) >= 0) {
cb->set_cc_config(context, rock, "vendor", tmp);
free(tmp);
}
if (ti->alg_id.length > 0 &&
asprintf(&tmp, "%.*s", ti->alg_id.length, ti->alg_id.data) >= 0) {
cb->set_cc_config(context, rock, "algID", tmp);
free(tmp);
}
if (ti->token_id.length > 0 &&
asprintf(&tmp, "%.*s", ti->token_id.length, ti->token_id.data) >= 0) {
cb->set_cc_config(context, rock, "tokenID", tmp);
free(tmp);
}
}
static krb5_error_code
otp_client_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 *pa_data,
krb5_prompter_fct prompter, void *prompter_data,
krb5_pa_data ***pa_data_out)
{
krb5_pa_otp_challenge *chl = NULL;
krb5_otp_tokeninfo *ti = NULL;
krb5_keyblock *as_key = NULL;
krb5_pa_otp_req *req = NULL;
krb5_error_code retval = 0;
krb5_data value, pin;
const char *answer;
if (modreq == NULL)
return ENOMEM;
chl = *(krb5_pa_otp_challenge **)modreq;
*pa_data_out = NULL;
/* Get FAST armor key. */
as_key = cb->fast_armor(context, rock);
if (as_key == NULL)
return ENOENT;
/* Attempt to get token selection from the responder. */
pin = empty_data();
value = empty_data();
answer = cb->get_responder_answer(context, rock,
KRB5_RESPONDER_QUESTION_OTP);
retval = codec_decode_answer(context, answer, chl->tokeninfo, &ti, &value,
&pin);
if (retval != 0) {
/* If the responder doesn't have a token selection,
* we need to select the token via prompting. */
retval = prompt_for_token(context, prompter, prompter_data,
chl->tokeninfo, &ti, &value, &pin);
if (retval != 0)
goto error;
}
/* Make the request. */
retval = make_request(context, ti, &value, &pin, &req);
if (retval != 0)
goto error;
/* Save information about the token which was used. */
save_config_tokeninfo(context, cb, rock, ti);
/* Encrypt the challenge's nonce and set it in the request. */
retval = encrypt_nonce(context, as_key, chl, req);
if (retval != 0)
goto error;
/* Use FAST armor key as response key. */
retval = cb->set_as_key(context, rock, as_key);
if (retval != 0)
goto error;
/* Encode the request into the pa_data output. */
retval = set_pa_data(req, pa_data_out);
error:
krb5_free_data_contents(context, &value);
krb5_free_data_contents(context, &pin);
k5_free_pa_otp_req(context, req);
return retval;
}
static void
otp_client_request_fini(krb5_context context, krb5_clpreauth_moddata moddata,
krb5_clpreauth_modreq modreq)
{
if (modreq == NULL)
return;
k5_free_pa_otp_challenge(context, *(krb5_pa_otp_challenge **)modreq);
free(modreq);
}
krb5_error_code
clpreauth_otp_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 = "otp";
vt->pa_type_list = otp_client_supported_pa_types;
vt->request_init = otp_client_request_init;
vt->prep_questions = otp_client_prep_questions;
vt->process = otp_client_process;
vt->request_fini = otp_client_request_fini;
vt->gic_opts = NULL;
return 0;
}
krb5_error_code KRB5_CALLCONV
krb5_responder_otp_get_challenge(krb5_context ctx,
krb5_responder_context rctx,
krb5_responder_otp_challenge **chl)
{
const char *answer;
krb5_responder_otp_challenge *challenge;
answer = krb5_responder_get_challenge(ctx, rctx,
KRB5_RESPONDER_QUESTION_OTP);
if (answer == NULL) {
*chl = NULL;
return 0;
}
challenge = codec_decode_challenge(ctx, answer);
if (challenge == NULL)
return ENOMEM;
*chl = challenge;
return 0;
}
krb5_error_code KRB5_CALLCONV
krb5_responder_otp_set_answer(krb5_context ctx, krb5_responder_context rctx,
size_t ti, const char *value, const char *pin)
{
krb5_error_code retval;
k5_json_object obj = NULL;
k5_json_number num;
k5_json_string str;
char *tmp;
retval = k5_json_object_create(&obj);
if (retval != 0)
goto error;
retval = k5_json_number_create(ti, &num);
if (retval != 0)
goto error;
retval = k5_json_object_set(obj, "tokeninfo", num);
k5_json_release(num);
if (retval != 0)
goto error;
if (value != NULL) {
retval = k5_json_string_create(value, &str);
if (retval != 0)
goto error;
retval = k5_json_object_set(obj, "value", str);
k5_json_release(str);
if (retval != 0)
goto error;
}
if (pin != NULL) {
retval = k5_json_string_create(pin, &str);
if (retval != 0)
goto error;
retval = k5_json_object_set(obj, "pin", str);
k5_json_release(str);
if (retval != 0)
goto error;
}
retval = k5_json_encode(obj, &tmp);
if (retval != 0)
goto error;
k5_json_release(obj);
retval = krb5_responder_set_answer(ctx, rctx, KRB5_RESPONDER_QUESTION_OTP,
tmp);
free(tmp);
return retval;
error:
k5_json_release(obj);
return retval;
}
void KRB5_CALLCONV
krb5_responder_otp_challenge_free(krb5_context ctx,
krb5_responder_context rctx,
krb5_responder_otp_challenge *chl)
{
size_t i;
if (chl == NULL)
return;
for (i = 0; chl->tokeninfo[i]; i++)
free_tokeninfo(chl->tokeninfo[i]);
free(chl->service);
free(chl->tokeninfo);
free(chl);
}
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