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freebsd-nq/kdc/digest.c

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Vendor import of Heimdal 1.1
2008-05-07 13:39:42 +00:00
/*
* Copyright (c) 2006 - 2007 Kungliga Tekniska H<EFBFBD>gskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* 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.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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 "kdc_locl.h"
#include <hex.h>
RCSID("$Id: digest.c 22374 2007-12-28 18:36:52Z lha $");
#define MS_CHAP_V2 0x20
#define CHAP_MD5 0x10
#define DIGEST_MD5 0x08
#define NTLM_V2 0x04
#define NTLM_V1_SESSION 0x02
#define NTLM_V1 0x01
const struct units _kdc_digestunits[] = {
{"ms-chap-v2", 1U << 5},
{"chap-md5", 1U << 4},
{"digest-md5", 1U << 3},
{"ntlm-v2", 1U << 2},
{"ntlm-v1-session", 1U << 1},
{"ntlm-v1", 1U << 0},
{NULL, 0}
};
static krb5_error_code
get_digest_key(krb5_context context,
krb5_kdc_configuration *config,
hdb_entry_ex *server,
krb5_crypto *crypto)
{
krb5_error_code ret;
krb5_enctype enctype;
Key *key;
ret = _kdc_get_preferred_key(context,
config,
server,
"digest-service",
&enctype,
&key);
if (ret)
return ret;
return krb5_crypto_init(context, &key->key, 0, crypto);
}
/*
*
*/
static char *
get_ntlm_targetname(krb5_context context,
hdb_entry_ex *client)
{
char *targetname, *p;
targetname = strdup(krb5_principal_get_realm(context,
client->entry.principal));
if (targetname == NULL)
return NULL;
p = strchr(targetname, '.');
if (p)
*p = '\0';
strupr(targetname);
return targetname;
}
static krb5_error_code
fill_targetinfo(krb5_context context,
char *targetname,
hdb_entry_ex *client,
krb5_data *data)
{
struct ntlm_targetinfo ti;
krb5_error_code ret;
struct ntlm_buf d;
krb5_principal p;
const char *str;
memset(&ti, 0, sizeof(ti));
ti.domainname = targetname;
p = client->entry.principal;
str = krb5_principal_get_comp_string(context, p, 0);
if (str != NULL &&
(strcmp("host", str) == 0 ||
strcmp("ftp", str) == 0 ||
strcmp("imap", str) == 0 ||
strcmp("pop", str) == 0 ||
strcmp("smtp", str)))
{
str = krb5_principal_get_comp_string(context, p, 1);
ti.dnsservername = rk_UNCONST(str);
}
ret = heim_ntlm_encode_targetinfo(&ti, 1, &d);
if (ret)
return ret;
data->data = d.data;
data->length = d.length;
return 0;
}
static const unsigned char ms_chap_v2_magic1[39] = {
0x4D, 0x61, 0x67, 0x69, 0x63, 0x20, 0x73, 0x65, 0x72, 0x76,
0x65, 0x72, 0x20, 0x74, 0x6F, 0x20, 0x63, 0x6C, 0x69, 0x65,
0x6E, 0x74, 0x20, 0x73, 0x69, 0x67, 0x6E, 0x69, 0x6E, 0x67,
0x20, 0x63, 0x6F, 0x6E, 0x73, 0x74, 0x61, 0x6E, 0x74
};
static const unsigned char ms_chap_v2_magic2[41] = {
0x50, 0x61, 0x64, 0x20, 0x74, 0x6F, 0x20, 0x6D, 0x61, 0x6B,
0x65, 0x20, 0x69, 0x74, 0x20, 0x64, 0x6F, 0x20, 0x6D, 0x6F,
0x72, 0x65, 0x20, 0x74, 0x68, 0x61, 0x6E, 0x20, 0x6F, 0x6E,
0x65, 0x20, 0x69, 0x74, 0x65, 0x72, 0x61, 0x74, 0x69, 0x6F,
0x6E
};
static const unsigned char ms_rfc3079_magic1[27] = {
0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 0x20, 0x74,
0x68, 0x65, 0x20, 0x4d, 0x50, 0x50, 0x45, 0x20, 0x4d,
0x61, 0x73, 0x74, 0x65, 0x72, 0x20, 0x4b, 0x65, 0x79
};
/*
*
*/
static krb5_error_code
get_password_entry(krb5_context context,
krb5_kdc_configuration *config,
const char *username,
char **password)
{
krb5_principal clientprincipal;
krb5_error_code ret;
hdb_entry_ex *user;
HDB *db;
/* get username */
ret = krb5_parse_name(context, username, &clientprincipal);
if (ret)
return ret;
ret = _kdc_db_fetch(context, config, clientprincipal,
HDB_F_GET_CLIENT, &db, &user);
krb5_free_principal(context, clientprincipal);
if (ret)
return ret;
ret = hdb_entry_get_password(context, db, &user->entry, password);
if (ret || password == NULL) {
if (ret == 0) {
ret = EINVAL;
krb5_set_error_string(context, "password missing");
}
memset(user, 0, sizeof(*user));
}
_kdc_free_ent (context, user);
return ret;
}
/*
*
*/
krb5_error_code
_kdc_do_digest(krb5_context context,
krb5_kdc_configuration *config,
const DigestREQ *req, krb5_data *reply,
const char *from, struct sockaddr *addr)
{
krb5_error_code ret = 0;
krb5_ticket *ticket = NULL;
krb5_auth_context ac = NULL;
krb5_keytab id = NULL;
krb5_crypto crypto = NULL;
DigestReqInner ireq;
DigestRepInner r;
DigestREP rep;
krb5_flags ap_req_options;
krb5_data buf;
size_t size;
krb5_storage *sp = NULL;
Checksum res;
hdb_entry_ex *server = NULL, *user = NULL;
hdb_entry_ex *client = NULL;
char *client_name = NULL, *password = NULL;
krb5_data serverNonce;
if(!config->enable_digest) {
kdc_log(context, config, 0,
"Rejected digest request (disabled) from %s", from);
return KRB5KDC_ERR_POLICY;
}
krb5_data_zero(&buf);
krb5_data_zero(reply);
krb5_data_zero(&serverNonce);
memset(&ireq, 0, sizeof(ireq));
memset(&r, 0, sizeof(r));
memset(&rep, 0, sizeof(rep));
kdc_log(context, config, 0, "Digest request from %s", from);
ret = krb5_kt_resolve(context, "HDB:", &id);
if (ret) {
kdc_log(context, config, 0, "Can't open database for digest");
goto out;
}
ret = krb5_rd_req(context,
&ac,
&req->apReq,
NULL,
id,
&ap_req_options,
&ticket);
if (ret)
goto out;
/* check the server principal in the ticket matches digest/R@R */
{
krb5_principal principal = NULL;
const char *p, *r;
ret = krb5_ticket_get_server(context, ticket, &principal);
if (ret)
goto out;
ret = EINVAL;
krb5_set_error_string(context, "Wrong digest server principal used");
p = krb5_principal_get_comp_string(context, principal, 0);
if (p == NULL) {
krb5_free_principal(context, principal);
goto out;
}
if (strcmp(p, KRB5_DIGEST_NAME) != 0) {
krb5_free_principal(context, principal);
goto out;
}
p = krb5_principal_get_comp_string(context, principal, 1);
if (p == NULL) {
krb5_free_principal(context, principal);
goto out;
}
r = krb5_principal_get_realm(context, principal);
if (r == NULL) {
krb5_free_principal(context, principal);
goto out;
}
if (strcmp(p, r) != 0) {
krb5_free_principal(context, principal);
goto out;
}
krb5_clear_error_string(context);
ret = _kdc_db_fetch(context, config, principal,
HDB_F_GET_SERVER, NULL, &server);
if (ret)
goto out;
krb5_free_principal(context, principal);
}
/* check the client is allowed to do digest auth */
{
krb5_principal principal = NULL;
ret = krb5_ticket_get_client(context, ticket, &principal);
if (ret)
goto out;
ret = krb5_unparse_name(context, principal, &client_name);
if (ret) {
krb5_free_principal(context, principal);
goto out;
}
ret = _kdc_db_fetch(context, config, principal,
HDB_F_GET_CLIENT, NULL, &client);
krb5_free_principal(context, principal);
if (ret)
goto out;
if (client->entry.flags.allow_digest == 0) {
kdc_log(context, config, 0,
"Client %s tried to use digest "
"but is not allowed to",
client_name);
krb5_set_error_string(context,
"Client is not permitted to use digest");
ret = KRB5KDC_ERR_POLICY;
goto out;
}
}
/* unpack request */
{
krb5_keyblock *key;
ret = krb5_auth_con_getremotesubkey(context, ac, &key);
if (ret)
goto out;
if (key == NULL) {
krb5_set_error_string(context, "digest: remote subkey not found");
ret = EINVAL;
goto out;
}
ret = krb5_crypto_init(context, key, 0, &crypto);
krb5_free_keyblock (context, key);
if (ret)
goto out;
}
ret = krb5_decrypt_EncryptedData(context, crypto, KRB5_KU_DIGEST_ENCRYPT,
&req->innerReq, &buf);
krb5_crypto_destroy(context, crypto);
crypto = NULL;
if (ret)
goto out;
ret = decode_DigestReqInner(buf.data, buf.length, &ireq, NULL);
krb5_data_free(&buf);
if (ret) {
krb5_set_error_string(context, "Failed to decode digest inner request");
goto out;
}
kdc_log(context, config, 0, "Valid digest request from %s (%s)",
client_name, from);
/*
* Process the inner request
*/
switch (ireq.element) {
case choice_DigestReqInner_init: {
unsigned char server_nonce[16], identifier;
RAND_pseudo_bytes(&identifier, sizeof(identifier));
RAND_pseudo_bytes(server_nonce, sizeof(server_nonce));
server_nonce[0] = kdc_time & 0xff;
server_nonce[1] = (kdc_time >> 8) & 0xff;
server_nonce[2] = (kdc_time >> 16) & 0xff;
server_nonce[3] = (kdc_time >> 24) & 0xff;
r.element = choice_DigestRepInner_initReply;
hex_encode(server_nonce, sizeof(server_nonce), &r.u.initReply.nonce);
if (r.u.initReply.nonce == NULL) {
krb5_set_error_string(context, "Failed to decode server nonce");
ret = ENOMEM;
goto out;
}
sp = krb5_storage_emem();
if (sp == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "out of memory");
goto out;
}
ret = krb5_store_stringz(sp, ireq.u.init.type);
if (ret) {
krb5_clear_error_string(context);
goto out;
}
if (ireq.u.init.channel) {
char *s;
asprintf(&s, "%s-%s:%s", r.u.initReply.nonce,
ireq.u.init.channel->cb_type,
ireq.u.init.channel->cb_binding);
if (s == NULL) {
krb5_set_error_string(context, "Failed to allocate "
"channel binding");
ret = ENOMEM;
goto out;
}
free(r.u.initReply.nonce);
r.u.initReply.nonce = s;
}
ret = krb5_store_stringz(sp, r.u.initReply.nonce);
if (ret) {
krb5_clear_error_string(context);
goto out;
}
if (strcasecmp(ireq.u.init.type, "CHAP") == 0) {
r.u.initReply.identifier =
malloc(sizeof(*r.u.initReply.identifier));
if (r.u.initReply.identifier == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
asprintf(r.u.initReply.identifier, "%02X", identifier & 0xff);
if (*r.u.initReply.identifier == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
} else
r.u.initReply.identifier = NULL;
if (ireq.u.init.hostname) {
ret = krb5_store_stringz(sp, *ireq.u.init.hostname);
if (ret) {
krb5_clear_error_string(context);
goto out;
}
}
ret = krb5_storage_to_data(sp, &buf);
if (ret) {
krb5_clear_error_string(context);
goto out;
}
ret = get_digest_key(context, config, server, &crypto);
if (ret)
goto out;
ret = krb5_create_checksum(context,
crypto,
KRB5_KU_DIGEST_OPAQUE,
0,
buf.data,
buf.length,
&res);
krb5_crypto_destroy(context, crypto);
crypto = NULL;
krb5_data_free(&buf);
if (ret)
goto out;
ASN1_MALLOC_ENCODE(Checksum, buf.data, buf.length, &res, &size, ret);
free_Checksum(&res);
if (ret) {
krb5_set_error_string(context, "Failed to encode "
"checksum in digest request");
goto out;
}
if (size != buf.length)
krb5_abortx(context, "ASN1 internal error");
hex_encode(buf.data, buf.length, &r.u.initReply.opaque);
free(buf.data);
if (r.u.initReply.opaque == NULL) {
krb5_clear_error_string(context);
ret = ENOMEM;
goto out;
}
kdc_log(context, config, 0, "Digest %s init request successful from %s",
ireq.u.init.type, from);
break;
}
case choice_DigestReqInner_digestRequest: {
sp = krb5_storage_emem();
if (sp == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "out of memory");
goto out;
}
ret = krb5_store_stringz(sp, ireq.u.digestRequest.type);
if (ret) {
krb5_clear_error_string(context);
goto out;
}
krb5_store_stringz(sp, ireq.u.digestRequest.serverNonce);
if (ireq.u.digestRequest.hostname) {
ret = krb5_store_stringz(sp, *ireq.u.digestRequest.hostname);
if (ret) {
krb5_clear_error_string(context);
goto out;
}
}
buf.length = strlen(ireq.u.digestRequest.opaque);
buf.data = malloc(buf.length);
if (buf.data == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
ret = hex_decode(ireq.u.digestRequest.opaque, buf.data, buf.length);
if (ret <= 0) {
krb5_set_error_string(context, "Failed to decode opaque");
ret = ENOMEM;
goto out;
}
buf.length = ret;
ret = decode_Checksum(buf.data, buf.length, &res, NULL);
free(buf.data);
if (ret) {
krb5_set_error_string(context, "Failed to decode digest Checksum");
goto out;
}
ret = krb5_storage_to_data(sp, &buf);
if (ret) {
krb5_clear_error_string(context);
goto out;
}
serverNonce.length = strlen(ireq.u.digestRequest.serverNonce);
serverNonce.data = malloc(serverNonce.length);
if (serverNonce.data == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
/*
* CHAP does the checksum of the raw nonce, but do it for all
* types, since we need to check the timestamp.
*/
{
ssize_t ssize;
ssize = hex_decode(ireq.u.digestRequest.serverNonce,
serverNonce.data, serverNonce.length);
if (ssize <= 0) {
krb5_set_error_string(context, "Failed to decode serverNonce");
ret = ENOMEM;
goto out;
}
serverNonce.length = ssize;
}
ret = get_digest_key(context, config, server, &crypto);
if (ret)
goto out;
ret = krb5_verify_checksum(context, crypto,
KRB5_KU_DIGEST_OPAQUE,
buf.data, buf.length, &res);
krb5_crypto_destroy(context, crypto);
crypto = NULL;
if (ret)
goto out;
/* verify time */
{
unsigned char *p = serverNonce.data;
uint32_t t;
if (serverNonce.length < 4) {
krb5_set_error_string(context, "server nonce too short");
ret = EINVAL;
goto out;
}
t = p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
if (abs((kdc_time & 0xffffffff) - t) > context->max_skew) {
krb5_set_error_string(context, "time screw in server nonce ");
ret = EINVAL;
goto out;
}
}
if (strcasecmp(ireq.u.digestRequest.type, "CHAP") == 0) {
MD5_CTX ctx;
unsigned char md[MD5_DIGEST_LENGTH];
char *mdx;
char id;
if ((config->digests_allowed & CHAP_MD5) == 0) {
kdc_log(context, config, 0, "Digest CHAP MD5 not allowed");
goto out;
}
if (ireq.u.digestRequest.identifier == NULL) {
krb5_set_error_string(context, "Identifier missing "
"from CHAP request");
ret = EINVAL;
goto out;
}
if (hex_decode(*ireq.u.digestRequest.identifier, &id, 1) != 1) {
krb5_set_error_string(context, "failed to decode identifier");
ret = EINVAL;
goto out;
}
ret = get_password_entry(context, config,
ireq.u.digestRequest.username,
&password);
if (ret)
goto out;
MD5_Init(&ctx);
MD5_Update(&ctx, &id, 1);
MD5_Update(&ctx, password, strlen(password));
MD5_Update(&ctx, serverNonce.data, serverNonce.length);
MD5_Final(md, &ctx);
hex_encode(md, sizeof(md), &mdx);
if (mdx == NULL) {
krb5_clear_error_string(context);
ret = ENOMEM;
goto out;
}
r.element = choice_DigestRepInner_response;
ret = strcasecmp(mdx, ireq.u.digestRequest.responseData);
free(mdx);
if (ret == 0) {
r.u.response.success = TRUE;
} else {
kdc_log(context, config, 0,
"CHAP reply mismatch for %s",
ireq.u.digestRequest.username);
r.u.response.success = FALSE;
}
} else if (strcasecmp(ireq.u.digestRequest.type, "SASL-DIGEST-MD5") == 0) {
MD5_CTX ctx;
unsigned char md[MD5_DIGEST_LENGTH];
char *mdx;
char *A1, *A2;
if ((config->digests_allowed & DIGEST_MD5) == 0) {
kdc_log(context, config, 0, "Digest SASL MD5 not allowed");
goto out;
}
if (ireq.u.digestRequest.nonceCount == NULL)
goto out;
if (ireq.u.digestRequest.clientNonce == NULL)
goto out;
if (ireq.u.digestRequest.qop == NULL)
goto out;
if (ireq.u.digestRequest.realm == NULL)
goto out;
ret = get_password_entry(context, config,
ireq.u.digestRequest.username,
&password);
if (ret)
goto failed;
MD5_Init(&ctx);
MD5_Update(&ctx, ireq.u.digestRequest.username,
strlen(ireq.u.digestRequest.username));
MD5_Update(&ctx, ":", 1);
MD5_Update(&ctx, *ireq.u.digestRequest.realm,
strlen(*ireq.u.digestRequest.realm));
MD5_Update(&ctx, ":", 1);
MD5_Update(&ctx, password, strlen(password));
MD5_Final(md, &ctx);
MD5_Init(&ctx);
MD5_Update(&ctx, md, sizeof(md));
MD5_Update(&ctx, ":", 1);
MD5_Update(&ctx, ireq.u.digestRequest.serverNonce,
strlen(ireq.u.digestRequest.serverNonce));
MD5_Update(&ctx, ":", 1);
MD5_Update(&ctx, *ireq.u.digestRequest.nonceCount,
strlen(*ireq.u.digestRequest.nonceCount));
if (ireq.u.digestRequest.authid) {
MD5_Update(&ctx, ":", 1);
MD5_Update(&ctx, *ireq.u.digestRequest.authid,
strlen(*ireq.u.digestRequest.authid));
}
MD5_Final(md, &ctx);
hex_encode(md, sizeof(md), &A1);
if (A1 == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto failed;
}
MD5_Init(&ctx);
MD5_Update(&ctx, "AUTHENTICATE:", sizeof("AUTHENTICATE:") - 1);
MD5_Update(&ctx, *ireq.u.digestRequest.uri,
strlen(*ireq.u.digestRequest.uri));
/* conf|int */
if (strcmp(ireq.u.digestRequest.digest, "clear") != 0) {
static char conf_zeros[] = ":00000000000000000000000000000000";
MD5_Update(&ctx, conf_zeros, sizeof(conf_zeros) - 1);
}
MD5_Final(md, &ctx);
hex_encode(md, sizeof(md), &A2);
if (A2 == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
free(A1);
goto failed;
}
MD5_Init(&ctx);
MD5_Update(&ctx, A1, strlen(A2));
MD5_Update(&ctx, ":", 1);
MD5_Update(&ctx, ireq.u.digestRequest.serverNonce,
strlen(ireq.u.digestRequest.serverNonce));
MD5_Update(&ctx, ":", 1);
MD5_Update(&ctx, *ireq.u.digestRequest.nonceCount,
strlen(*ireq.u.digestRequest.nonceCount));
MD5_Update(&ctx, ":", 1);
MD5_Update(&ctx, *ireq.u.digestRequest.clientNonce,
strlen(*ireq.u.digestRequest.clientNonce));
MD5_Update(&ctx, ":", 1);
MD5_Update(&ctx, *ireq.u.digestRequest.qop,
strlen(*ireq.u.digestRequest.qop));
MD5_Update(&ctx, ":", 1);
MD5_Update(&ctx, A2, strlen(A2));
MD5_Final(md, &ctx);
free(A1);
free(A2);
hex_encode(md, sizeof(md), &mdx);
if (mdx == NULL) {
krb5_clear_error_string(context);
ret = ENOMEM;
goto out;
}
r.element = choice_DigestRepInner_response;
ret = strcasecmp(mdx, ireq.u.digestRequest.responseData);
free(mdx);
if (ret == 0) {
r.u.response.success = TRUE;
} else {
kdc_log(context, config, 0,
"DIGEST-MD5 reply mismatch for %s",
ireq.u.digestRequest.username);
r.u.response.success = FALSE;
}
} else if (strcasecmp(ireq.u.digestRequest.type, "MS-CHAP-V2") == 0) {
unsigned char md[SHA_DIGEST_LENGTH], challange[SHA_DIGEST_LENGTH];
krb5_principal clientprincipal = NULL;
char *mdx;
const char *username;
struct ntlm_buf answer;
Key *key = NULL;
SHA_CTX ctx;
if ((config->digests_allowed & MS_CHAP_V2) == 0) {
kdc_log(context, config, 0, "MS-CHAP-V2 not allowed");
goto failed;
}
if (ireq.u.digestRequest.clientNonce == NULL) {
krb5_set_error_string(context,
"MS-CHAP-V2 clientNonce missing");
ret = EINVAL;
goto failed;
}
if (serverNonce.length != 16) {
krb5_set_error_string(context,
"MS-CHAP-V2 serverNonce wrong length");
ret = EINVAL;
goto failed;
}
/* strip of the domain component */
username = strchr(ireq.u.digestRequest.username, '\\');
if (username == NULL)
username = ireq.u.digestRequest.username;
else
username++;
/* ChallangeHash */
SHA1_Init(&ctx);
{
ssize_t ssize;
krb5_data clientNonce;
clientNonce.length = strlen(*ireq.u.digestRequest.clientNonce);
clientNonce.data = malloc(clientNonce.length);
if (clientNonce.data == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "out of memory");
goto out;
}
ssize = hex_decode(*ireq.u.digestRequest.clientNonce,
clientNonce.data, clientNonce.length);
if (ssize != 16) {
krb5_set_error_string(context,
"Failed to decode clientNonce");
ret = ENOMEM;
goto out;
}
SHA1_Update(&ctx, clientNonce.data, ssize);
free(clientNonce.data);
}
SHA1_Update(&ctx, serverNonce.data, serverNonce.length);
SHA1_Update(&ctx, username, strlen(username));
SHA1_Final(challange, &ctx);
/* NtPasswordHash */
ret = krb5_parse_name(context, username, &clientprincipal);
if (ret)
goto failed;
ret = _kdc_db_fetch(context, config, clientprincipal,
HDB_F_GET_CLIENT, NULL, &user);
krb5_free_principal(context, clientprincipal);
if (ret) {
krb5_set_error_string(context,
"MS-CHAP-V2 user %s not in database",
username);
goto failed;
}
ret = hdb_enctype2key(context, &user->entry,
ETYPE_ARCFOUR_HMAC_MD5, &key);
if (ret) {
krb5_set_error_string(context,
"MS-CHAP-V2 missing arcfour key %s",
username);
goto failed;
}
/* ChallengeResponse */
ret = heim_ntlm_calculate_ntlm1(key->key.keyvalue.data,
key->key.keyvalue.length,
challange, &answer);
if (ret) {
krb5_set_error_string(context, "NTLM missing arcfour key");
goto failed;
}
hex_encode(answer.data, answer.length, &mdx);
if (mdx == NULL) {
free(answer.data);
krb5_clear_error_string(context);
ret = ENOMEM;
goto out;
}
r.element = choice_DigestRepInner_response;
ret = strcasecmp(mdx, ireq.u.digestRequest.responseData);
if (ret == 0) {
r.u.response.success = TRUE;
} else {
kdc_log(context, config, 0,
"MS-CHAP-V2 hash mismatch for %s",
ireq.u.digestRequest.username);
r.u.response.success = FALSE;
}
free(mdx);
if (r.u.response.success) {
unsigned char hashhash[MD4_DIGEST_LENGTH];
/* hashhash */
{
MD4_CTX hctx;
MD4_Init(&hctx);
MD4_Update(&hctx, key->key.keyvalue.data,
key->key.keyvalue.length);
MD4_Final(hashhash, &hctx);
}
/* GenerateAuthenticatorResponse */
SHA1_Init(&ctx);
SHA1_Update(&ctx, hashhash, sizeof(hashhash));
SHA1_Update(&ctx, answer.data, answer.length);
SHA1_Update(&ctx, ms_chap_v2_magic1,sizeof(ms_chap_v2_magic1));
SHA1_Final(md, &ctx);
SHA1_Init(&ctx);
SHA1_Update(&ctx, md, sizeof(md));
SHA1_Update(&ctx, challange, 8);
SHA1_Update(&ctx, ms_chap_v2_magic2, sizeof(ms_chap_v2_magic2));
SHA1_Final(md, &ctx);
r.u.response.rsp = calloc(1, sizeof(*r.u.response.rsp));
if (r.u.response.rsp == NULL) {
free(answer.data);
krb5_clear_error_string(context);
ret = ENOMEM;
goto out;
}
hex_encode(md, sizeof(md), r.u.response.rsp);
if (r.u.response.rsp == NULL) {
free(answer.data);
krb5_clear_error_string(context);
ret = ENOMEM;
goto out;
}
/* get_master, rfc 3079 3.4 */
SHA1_Init(&ctx);
SHA1_Update(&ctx, hashhash, 16); /* md4(hash) */
SHA1_Update(&ctx, answer.data, answer.length);
SHA1_Update(&ctx, ms_rfc3079_magic1, sizeof(ms_rfc3079_magic1));
SHA1_Final(md, &ctx);
free(answer.data);
r.u.response.session_key =
calloc(1, sizeof(*r.u.response.session_key));
if (r.u.response.session_key == NULL) {
krb5_clear_error_string(context);
ret = ENOMEM;
goto out;
}
ret = krb5_data_copy(r.u.response.session_key, md, 16);
if (ret) {
krb5_clear_error_string(context);
goto out;
}
}
} else {
r.element = choice_DigestRepInner_error;
asprintf(&r.u.error.reason, "Unsupported digest type %s",
ireq.u.digestRequest.type);
if (r.u.error.reason == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
r.u.error.code = EINVAL;
}
kdc_log(context, config, 0, "Digest %s request successful %s",
ireq.u.digestRequest.type, ireq.u.digestRequest.username);
break;
}
case choice_DigestReqInner_ntlmInit:
if ((config->digests_allowed & (NTLM_V1|NTLM_V1_SESSION|NTLM_V2)) == 0) {
kdc_log(context, config, 0, "NTLM not allowed");
goto failed;
}
r.element = choice_DigestRepInner_ntlmInitReply;
r.u.ntlmInitReply.flags = NTLM_NEG_UNICODE;
if ((ireq.u.ntlmInit.flags & NTLM_NEG_UNICODE) == 0) {
kdc_log(context, config, 0, "NTLM client have no unicode");
goto failed;
}
if (ireq.u.ntlmInit.flags & NTLM_NEG_NTLM)
r.u.ntlmInitReply.flags |= NTLM_NEG_NTLM;
else {
kdc_log(context, config, 0, "NTLM client doesn't support NTLM");
goto failed;
}
r.u.ntlmInitReply.flags |=
NTLM_NEG_TARGET |
NTLM_TARGET_DOMAIN |
NTLM_ENC_128;
#define ALL \
NTLM_NEG_SIGN| \
NTLM_NEG_SEAL| \
NTLM_NEG_ALWAYS_SIGN| \
NTLM_NEG_NTLM2_SESSION| \
NTLM_NEG_KEYEX
r.u.ntlmInitReply.flags |= (ireq.u.ntlmInit.flags & (ALL));
#undef ALL
r.u.ntlmInitReply.targetname =
get_ntlm_targetname(context, client);
if (r.u.ntlmInitReply.targetname == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
r.u.ntlmInitReply.challange.data = malloc(8);
if (r.u.ntlmInitReply.challange.data == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
r.u.ntlmInitReply.challange.length = 8;
if (RAND_bytes(r.u.ntlmInitReply.challange.data,
r.u.ntlmInitReply.challange.length) != 1)
{
krb5_set_error_string(context, "out of random error");
ret = ENOMEM;
goto out;
}
/* XXX fix targetinfo */
ALLOC(r.u.ntlmInitReply.targetinfo);
if (r.u.ntlmInitReply.targetinfo == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
ret = fill_targetinfo(context,
r.u.ntlmInitReply.targetname,
client,
r.u.ntlmInitReply.targetinfo);
if (ret) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
/*
* Save data encryted in opaque for the second part of the
* ntlm authentication
*/
sp = krb5_storage_emem();
if (sp == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "out of memory");
goto out;
}
ret = krb5_storage_write(sp, r.u.ntlmInitReply.challange.data, 8);
if (ret != 8) {
ret = ENOMEM;
krb5_set_error_string(context, "storage write challange");
goto out;
}
ret = krb5_store_uint32(sp, r.u.ntlmInitReply.flags);
if (ret) {
krb5_clear_error_string(context);
goto out;
}
ret = krb5_storage_to_data(sp, &buf);
if (ret) {
krb5_clear_error_string(context);
goto out;
}
ret = get_digest_key(context, config, server, &crypto);
if (ret)
goto out;
ret = krb5_encrypt(context, crypto, KRB5_KU_DIGEST_OPAQUE,
buf.data, buf.length, &r.u.ntlmInitReply.opaque);
krb5_data_free(&buf);
krb5_crypto_destroy(context, crypto);
crypto = NULL;
if (ret)
goto out;
kdc_log(context, config, 0, "NTLM init from %s", from);
break;
case choice_DigestReqInner_ntlmRequest: {
krb5_principal clientprincipal;
unsigned char sessionkey[16];
unsigned char challange[8];
uint32_t flags;
Key *key = NULL;
int version;
r.element = choice_DigestRepInner_ntlmResponse;
r.u.ntlmResponse.success = 0;
r.u.ntlmResponse.flags = 0;
r.u.ntlmResponse.sessionkey = NULL;
r.u.ntlmResponse.tickets = NULL;
/* get username */
ret = krb5_parse_name(context,
ireq.u.ntlmRequest.username,
&clientprincipal);
if (ret)
goto failed;
ret = _kdc_db_fetch(context, config, clientprincipal,
HDB_F_GET_CLIENT, NULL, &user);
krb5_free_principal(context, clientprincipal);
if (ret) {
krb5_set_error_string(context, "NTLM user %s not in database",
ireq.u.ntlmRequest.username);
goto failed;
}
ret = get_digest_key(context, config, server, &crypto);
if (ret)
goto failed;
ret = krb5_decrypt(context, crypto, KRB5_KU_DIGEST_OPAQUE,
ireq.u.ntlmRequest.opaque.data,
ireq.u.ntlmRequest.opaque.length, &buf);
krb5_crypto_destroy(context, crypto);
crypto = NULL;
if (ret) {
kdc_log(context, config, 0,
"Failed to decrypt nonce from %s", from);
goto failed;
}
sp = krb5_storage_from_data(&buf);
if (sp == NULL) {
ret = ENOMEM;
krb5_set_error_string(context, "out of memory");
goto out;
}
ret = krb5_storage_read(sp, challange, sizeof(challange));
if (ret != sizeof(challange)) {
krb5_set_error_string(context, "NTLM storage read challange");
ret = ENOMEM;
goto out;
}
ret = krb5_ret_uint32(sp, &flags);
if (ret) {
krb5_set_error_string(context, "NTLM storage read flags");
goto out;
}
krb5_data_free(&buf);
if ((flags & NTLM_NEG_NTLM) == 0) {
ret = EINVAL;
krb5_set_error_string(context, "NTLM not negotiated");
goto out;
}
ret = hdb_enctype2key(context, &user->entry,
ETYPE_ARCFOUR_HMAC_MD5, &key);
if (ret) {
krb5_set_error_string(context, "NTLM missing arcfour key");
goto out;
}
/* check if this is NTLMv2 */
if (ireq.u.ntlmRequest.ntlm.length != 24) {
struct ntlm_buf infotarget, answer;
char *targetname;
if ((config->digests_allowed & NTLM_V2) == 0) {
kdc_log(context, config, 0, "NTLM v2 not allowed");
goto out;
}
version = 2;
targetname = get_ntlm_targetname(context, client);
if (targetname == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
answer.length = ireq.u.ntlmRequest.ntlm.length;
answer.data = ireq.u.ntlmRequest.ntlm.data;
ret = heim_ntlm_verify_ntlm2(key->key.keyvalue.data,
key->key.keyvalue.length,
ireq.u.ntlmRequest.username,
targetname,
0,
challange,
&answer,
&infotarget,
sessionkey);
free(targetname);
if (ret) {
krb5_set_error_string(context, "NTLM v2 verify failed");
goto failed;
}
/* XXX verify infotarget matches client (checksum ?) */
free(infotarget.data);
/* */
} else {
struct ntlm_buf answer;
version = 1;
if (flags & NTLM_NEG_NTLM2_SESSION) {
unsigned char sessionhash[MD5_DIGEST_LENGTH];
MD5_CTX md5ctx;
if ((config->digests_allowed & NTLM_V1_SESSION) == 0) {
kdc_log(context, config, 0, "NTLM v1-session not allowed");
ret = EINVAL;
goto failed;
}
if (ireq.u.ntlmRequest.lm.length != 24) {
krb5_set_error_string(context, "LM hash have wrong length "
"for NTLM session key");
ret = EINVAL;
goto failed;
}
MD5_Init(&md5ctx);
MD5_Update(&md5ctx, challange, sizeof(challange));
MD5_Update(&md5ctx, ireq.u.ntlmRequest.lm.data, 8);
MD5_Final(sessionhash, &md5ctx);
memcpy(challange, sessionhash, sizeof(challange));
} else {
if ((config->digests_allowed & NTLM_V1) == 0) {
kdc_log(context, config, 0, "NTLM v1 not allowed");
goto failed;
}
}
ret = heim_ntlm_calculate_ntlm1(key->key.keyvalue.data,
key->key.keyvalue.length,
challange, &answer);
if (ret) {
krb5_set_error_string(context, "NTLM missing arcfour key");
goto failed;
}
if (ireq.u.ntlmRequest.ntlm.length != answer.length ||
memcmp(ireq.u.ntlmRequest.ntlm.data, answer.data, answer.length) != 0)
{
free(answer.data);
ret = EINVAL;
krb5_set_error_string(context, "NTLM hash mismatch");
goto failed;
}
free(answer.data);
{
MD4_CTX ctx;
MD4_Init(&ctx);
MD4_Update(&ctx,
key->key.keyvalue.data, key->key.keyvalue.length);
MD4_Final(sessionkey, &ctx);
}
}
if (ireq.u.ntlmRequest.sessionkey) {
unsigned char masterkey[MD4_DIGEST_LENGTH];
RC4_KEY rc4;
size_t len;
if ((flags & NTLM_NEG_KEYEX) == 0) {
krb5_set_error_string(context,
"NTLM client failed to neg key "
"exchange but still sent key");
ret = EINVAL;
goto failed;
}
len = ireq.u.ntlmRequest.sessionkey->length;
if (len != sizeof(masterkey)){
krb5_set_error_string(context,
"NTLM master key wrong length: %lu",
(unsigned long)len);
goto failed;
}
RC4_set_key(&rc4, sizeof(sessionkey), sessionkey);
RC4(&rc4, sizeof(masterkey),
ireq.u.ntlmRequest.sessionkey->data,
masterkey);
memset(&rc4, 0, sizeof(rc4));
r.u.ntlmResponse.sessionkey =
malloc(sizeof(*r.u.ntlmResponse.sessionkey));
if (r.u.ntlmResponse.sessionkey == NULL) {
krb5_set_error_string(context, "out of memory");
goto out;
}
ret = krb5_data_copy(r.u.ntlmResponse.sessionkey,
masterkey, sizeof(masterkey));
if (ret) {
krb5_set_error_string(context, "out of memory");
goto out;
}
}
r.u.ntlmResponse.success = 1;
kdc_log(context, config, 0, "NTLM version %d successful for %s",
version, ireq.u.ntlmRequest.username);
break;
}
case choice_DigestReqInner_supportedMechs:
kdc_log(context, config, 0, "digest supportedMechs from %s", from);
r.element = choice_DigestRepInner_supportedMechs;
memset(&r.u.supportedMechs, 0, sizeof(r.u.supportedMechs));
if (config->digests_allowed & NTLM_V1)
r.u.supportedMechs.ntlm_v1 = 1;
if (config->digests_allowed & NTLM_V1_SESSION)
r.u.supportedMechs.ntlm_v1_session = 1;
if (config->digests_allowed & NTLM_V2)
r.u.supportedMechs.ntlm_v2 = 1;
if (config->digests_allowed & DIGEST_MD5)
r.u.supportedMechs.digest_md5 = 1;
if (config->digests_allowed & CHAP_MD5)
r.u.supportedMechs.chap_md5 = 1;
if (config->digests_allowed & MS_CHAP_V2)
r.u.supportedMechs.ms_chap_v2 = 1;
break;
default: {
char *s;
krb5_set_error_string(context, "unknown operation to digest");
ret = EINVAL;
failed:
s = krb5_get_error_message(context, ret);
if (s == NULL) {
krb5_clear_error_string(context);
goto out;
}
kdc_log(context, config, 0, "Digest failed with: %s", s);
r.element = choice_DigestRepInner_error;
r.u.error.reason = strdup("unknown error");
krb5_free_error_string(context, s);
if (r.u.error.reason == NULL) {
krb5_set_error_string(context, "out of memory");
ret = ENOMEM;
goto out;
}
r.u.error.code = EINVAL;
break;
}
}
ASN1_MALLOC_ENCODE(DigestRepInner, buf.data, buf.length, &r, &size, ret);
if (ret) {
krb5_set_error_string(context, "Failed to encode inner digest reply");
goto out;
}
if (size != buf.length)
krb5_abortx(context, "ASN1 internal error");
krb5_auth_con_addflags(context, ac, KRB5_AUTH_CONTEXT_USE_SUBKEY, NULL);
ret = krb5_mk_rep (context, ac, &rep.apRep);
if (ret)
goto out;
{
krb5_keyblock *key;
ret = krb5_auth_con_getlocalsubkey(context, ac, &key);
if (ret)
goto out;
ret = krb5_crypto_init(context, key, 0, &crypto);
krb5_free_keyblock (context, key);
if (ret)
goto out;
}
ret = krb5_encrypt_EncryptedData(context, crypto, KRB5_KU_DIGEST_ENCRYPT,
buf.data, buf.length, 0,
&rep.innerRep);
ASN1_MALLOC_ENCODE(DigestREP, reply->data, reply->length, &rep, &size, ret);
if (ret) {
krb5_set_error_string(context, "Failed to encode digest reply");
goto out;
}
if (size != reply->length)
krb5_abortx(context, "ASN1 internal error");
out:
if (ac)
krb5_auth_con_free(context, ac);
if (ret)
krb5_warn(context, ret, "Digest request from %s failed", from);
if (ticket)
krb5_free_ticket(context, ticket);
if (id)
krb5_kt_close(context, id);
if (crypto)
krb5_crypto_destroy(context, crypto);
if (sp)
krb5_storage_free(sp);
if (user)
_kdc_free_ent (context, user);
if (server)
_kdc_free_ent (context, server);
if (client)
_kdc_free_ent (context, client);
if (password) {
memset(password, 0, strlen(password));
free (password);
}
if (client_name)
free (client_name);
krb5_data_free(&buf);
krb5_data_free(&serverNonce);
free_DigestREP(&rep);
free_DigestRepInner(&r);
free_DigestReqInner(&ireq);
return ret;
}
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