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FreeRDP/libfreerdp/core/nla.c
Armin Novak 09f679da61 [coverity] 1543075 Explicit null dereferenced
2024-04-15 11:30:31 +02:00

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/**
* FreeRDP: A Remote Desktop Protocol Implementation
* Network Level Authentication (NLA)
*
* Copyright 2010-2012 Marc-Andre Moreau <marcandre.moreau@gmail.com>
* Copyright 2015 Thincast Technologies GmbH
* Copyright 2015 DI (FH) Martin Haimberger <martin.haimberger@thincast.com>
* Copyright 2016 Martin Fleisz <martin.fleisz@thincast.com>
* Copyright 2017 Dorian Ducournau <dorian.ducournau@gmail.com>
* Copyright 2022 David Fort <contact@hardening-consulting.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <freerdp/config.h>
#include "settings.h"
#include <time.h>
#include <ctype.h>
#include <freerdp/log.h>
#include <freerdp/build-config.h>
#include <winpr/crt.h>
#include <winpr/assert.h>
#include <winpr/sam.h>
#include <winpr/sspi.h>
#include <winpr/print.h>
#include <winpr/tchar.h>
#include <winpr/ncrypt.h>
#include <winpr/cred.h>
#include <winpr/debug.h>
#include <winpr/asn1.h>
#include <winpr/secapi.h>
#include "../crypto/tls.h"
#include "nego.h"
#include "rdp.h"
#include "nla.h"
#include "utils.h"
#include "credssp_auth.h"
#include <freerdp/utils/smartcardlogon.h>
#define TAG FREERDP_TAG("core.nla")
#define SERVER_KEY "Software\\" FREERDP_VENDOR_STRING "\\" FREERDP_PRODUCT_STRING "\\Server"
#define NLA_AUTH_PKG NEGO_SSP_NAME
typedef enum
{
AUTHZ_SUCCESS = 0x00000000,
AUTHZ_ACCESS_DENIED = 0x00000005,
} AUTHZ_RESULT;
/**
* TSRequest ::= SEQUENCE {
* version [0] INTEGER,
* negoTokens [1] NegoData OPTIONAL,
* authInfo [2] OCTET STRING OPTIONAL,
* pubKeyAuth [3] OCTET STRING OPTIONAL,
* errorCode [4] INTEGER OPTIONAL
* }
*
* NegoData ::= SEQUENCE OF NegoDataItem
*
* NegoDataItem ::= SEQUENCE {
* negoToken [0] OCTET STRING
* }
*
* TSCredentials ::= SEQUENCE {
* credType [0] INTEGER,
* credentials [1] OCTET STRING
* }
*
* TSPasswordCreds ::= SEQUENCE {
* domainName [0] OCTET STRING,
* userName [1] OCTET STRING,
* password [2] OCTET STRING
* }
*
* TSSmartCardCreds ::= SEQUENCE {
* pin [0] OCTET STRING,
* cspData [1] TSCspDataDetail,
* userHint [2] OCTET STRING OPTIONAL,
* domainHint [3] OCTET STRING OPTIONAL
* }
*
* TSCspDataDetail ::= SEQUENCE {
* keySpec [0] INTEGER,
* cardName [1] OCTET STRING OPTIONAL,
* readerName [2] OCTET STRING OPTIONAL,
* containerName [3] OCTET STRING OPTIONAL,
* cspName [4] OCTET STRING OPTIONAL
* }
*
*/
#define NLA_PKG_NAME CREDSSP_AUTH_PKG_SPNEGO
struct rdp_nla
{
BOOL server;
NLA_STATE state;
ULONG sendSeqNum;
ULONG recvSeqNum;
rdpContext* rdpcontext;
rdpTransport* transport;
UINT32 version;
UINT32 peerVersion;
UINT32 errorCode;
/* Lifetime of buffer nla_new -> nla_free */
SecBuffer ClientNonce; /* Depending on protocol version a random nonce or a value read from the
server. */
SecBuffer negoToken;
SecBuffer pubKeyAuth;
SecBuffer authInfo;
SecBuffer PublicKey;
SecBuffer tsCredentials;
SEC_WINNT_AUTH_IDENTITY* identity;
rdpCredsspAuth* auth;
char* pkinitArgs;
SmartcardCertInfo* smartcardCert;
BYTE certSha1[20];
BOOL earlyUserAuth;
};
static BOOL nla_send(rdpNla* nla);
static int nla_server_recv(rdpNla* nla);
static BOOL nla_encrypt_public_key_echo(rdpNla* nla);
static BOOL nla_encrypt_public_key_hash(rdpNla* nla);
static BOOL nla_decrypt_public_key_echo(rdpNla* nla);
static BOOL nla_decrypt_public_key_hash(rdpNla* nla);
static BOOL nla_encrypt_ts_credentials(rdpNla* nla);
static BOOL nla_decrypt_ts_credentials(rdpNla* nla);
void nla_set_early_user_auth(rdpNla* nla, BOOL earlyUserAuth)
{
WINPR_ASSERT(nla);
WLog_DBG(TAG, "Early User Auth active: %s", earlyUserAuth ? "true" : "false");
nla->earlyUserAuth = earlyUserAuth;
}
static void nla_buffer_free(rdpNla* nla)
{
WINPR_ASSERT(nla);
sspi_SecBufferFree(&nla->pubKeyAuth);
sspi_SecBufferFree(&nla->authInfo);
sspi_SecBufferFree(&nla->negoToken);
sspi_SecBufferFree(&nla->ClientNonce);
sspi_SecBufferFree(&nla->PublicKey);
}
static BOOL nla_Digest_Update_From_SecBuffer(WINPR_DIGEST_CTX* ctx, const SecBuffer* buffer)
{
if (!buffer)
return FALSE;
return winpr_Digest_Update(ctx, buffer->pvBuffer, buffer->cbBuffer);
}
static BOOL nla_sec_buffer_alloc(SecBuffer* buffer, size_t size)
{
WINPR_ASSERT(buffer);
sspi_SecBufferFree(buffer);
if (size > ULONG_MAX)
return FALSE;
if (!sspi_SecBufferAlloc(buffer, (ULONG)size))
return FALSE;
WINPR_ASSERT(buffer);
buffer->BufferType = SECBUFFER_TOKEN;
return TRUE;
}
static BOOL nla_sec_buffer_alloc_from_data(SecBuffer* buffer, const BYTE* data, size_t offset,
size_t size)
{
if (!nla_sec_buffer_alloc(buffer, offset + size))
return FALSE;
WINPR_ASSERT(buffer);
BYTE* pb = buffer->pvBuffer;
memcpy(&pb[offset], data, size);
return TRUE;
}
/* CredSSP Client-To-Server Binding Hash\0 */
static const BYTE ClientServerHashMagic[] = { 0x43, 0x72, 0x65, 0x64, 0x53, 0x53, 0x50, 0x20,
0x43, 0x6C, 0x69, 0x65, 0x6E, 0x74, 0x2D, 0x54,
0x6F, 0x2D, 0x53, 0x65, 0x72, 0x76, 0x65, 0x72,
0x20, 0x42, 0x69, 0x6E, 0x64, 0x69, 0x6E, 0x67,
0x20, 0x48, 0x61, 0x73, 0x68, 0x00 };
/* CredSSP Server-To-Client Binding Hash\0 */
static const BYTE ServerClientHashMagic[] = { 0x43, 0x72, 0x65, 0x64, 0x53, 0x53, 0x50, 0x20,
0x53, 0x65, 0x72, 0x76, 0x65, 0x72, 0x2D, 0x54,
0x6F, 0x2D, 0x43, 0x6C, 0x69, 0x65, 0x6E, 0x74,
0x20, 0x42, 0x69, 0x6E, 0x64, 0x69, 0x6E, 0x67,
0x20, 0x48, 0x61, 0x73, 0x68, 0x00 };
static const UINT32 NonceLength = 32;
static BOOL nla_adjust_settings_from_smartcard(rdpNla* nla)
{
BOOL ret = FALSE;
WINPR_ASSERT(nla);
WINPR_ASSERT(nla->rdpcontext);
rdpSettings* settings = nla->rdpcontext->settings;
WINPR_ASSERT(settings);
if (!settings->SmartcardLogon)
return TRUE;
smartcardCertInfo_Free(nla->smartcardCert);
if (!smartcard_getCert(nla->rdpcontext, &nla->smartcardCert, FALSE))
{
WLog_ERR(TAG, "unable to get smartcard certificate for logon");
return FALSE;
}
if (!settings->CspName)
{
if (nla->smartcardCert->csp && !freerdp_settings_set_string_from_utf16(
settings, FreeRDP_CspName, nla->smartcardCert->csp))
{
WLog_ERR(TAG, "unable to set CSP name");
goto out;
}
if (!settings->CspName &&
!freerdp_settings_set_string(settings, FreeRDP_CspName, MS_SCARD_PROV_A))
{
WLog_ERR(TAG, "unable to set CSP name");
goto out;
}
}
if (!settings->ReaderName && nla->smartcardCert->reader)
{
if (!freerdp_settings_set_string_from_utf16(settings, FreeRDP_ReaderName,
nla->smartcardCert->reader))
{
WLog_ERR(TAG, "unable to copy reader name");
goto out;
}
}
if (!settings->ContainerName && nla->smartcardCert->containerName)
{
if (!freerdp_settings_set_string_from_utf16(settings, FreeRDP_ContainerName,
nla->smartcardCert->containerName))
{
WLog_ERR(TAG, "unable to copy container name");
goto out;
}
}
memcpy(nla->certSha1, nla->smartcardCert->sha1Hash, sizeof(nla->certSha1));
if (nla->smartcardCert->pkinitArgs)
{
nla->pkinitArgs = _strdup(nla->smartcardCert->pkinitArgs);
if (!nla->pkinitArgs)
{
WLog_ERR(TAG, "unable to copy pkinitArgs");
goto out;
}
}
ret = TRUE;
out:
return ret;
}
static BOOL nla_client_setup_identity(rdpNla* nla)
{
BOOL PromptPassword = FALSE;
WINPR_ASSERT(nla);
WINPR_ASSERT(nla->rdpcontext);
rdpSettings* settings = nla->rdpcontext->settings;
WINPR_ASSERT(settings);
freerdp* instance = nla->rdpcontext->instance;
WINPR_ASSERT(instance);
/* */
if ((utils_str_is_empty(settings->Username) ||
(utils_str_is_empty(settings->Password) &&
utils_str_is_empty((const char*)settings->RedirectionPassword))))
{
PromptPassword = TRUE;
}
if (PromptPassword && !utils_str_is_empty(settings->Username))
{
WINPR_SAM* sam = SamOpen(NULL, TRUE);
if (sam)
{
const size_t userLength = strlen(settings->Username);
WINPR_SAM_ENTRY* entry = SamLookupUserA(
sam, settings->Username, userLength + 1 /* ensure '\0' is checked too */, NULL, 0);
if (entry)
{
/**
* The user could be found in SAM database.
* Use entry in SAM database later instead of prompt
*/
PromptPassword = FALSE;
SamFreeEntry(sam, entry);
}
SamClose(sam);
}
}
#ifndef _WIN32
if (PromptPassword)
{
if (settings->RestrictedAdminModeRequired)
{
if ((settings->PasswordHash) && (strlen(settings->PasswordHash) > 0))
PromptPassword = FALSE;
}
if (settings->RemoteCredentialGuard)
PromptPassword = FALSE;
}
#endif
BOOL smartCardLogonWasDisabled = !settings->SmartcardLogon;
if (PromptPassword)
{
switch (utils_authenticate(instance, AUTH_NLA, TRUE))
{
case AUTH_SKIP:
case AUTH_SUCCESS:
break;
case AUTH_CANCELLED:
freerdp_set_last_error_log(instance->context, FREERDP_ERROR_CONNECT_CANCELLED);
return FALSE;
case AUTH_NO_CREDENTIALS:
WLog_INFO(TAG, "No credentials provided - using NULL identity");
break;
default:
return FALSE;
}
}
if (!settings->Username)
{
sspi_FreeAuthIdentity(nla->identity);
nla->identity = NULL;
}
else if (settings->SmartcardLogon)
{
if (smartCardLogonWasDisabled)
{
if (!nla_adjust_settings_from_smartcard(nla))
return FALSE;
}
if (!identity_set_from_smartcard_hash(nla->identity, settings, FreeRDP_Username,
FreeRDP_Domain, FreeRDP_Password, nla->certSha1,
sizeof(nla->certSha1)))
return FALSE;
}
else
{
BOOL usePassword = TRUE;
if (settings->RedirectionPassword && (settings->RedirectionPasswordLength > 0))
{
if (!identity_set_from_settings_with_pwd(
nla->identity, settings, FreeRDP_Username, FreeRDP_Domain,
(const WCHAR*)settings->RedirectionPassword,
settings->RedirectionPasswordLength / sizeof(WCHAR)))
return FALSE;
usePassword = FALSE;
}
if (settings->RestrictedAdminModeRequired)
{
if (settings->PasswordHash && strlen(settings->PasswordHash) == 32)
{
if (!identity_set_from_settings(nla->identity, settings, FreeRDP_Username,
FreeRDP_Domain, FreeRDP_PasswordHash))
return FALSE;
/**
* Increase password hash length by LB_PASSWORD_MAX_LENGTH to obtain a
* length exceeding the maximum (LB_PASSWORD_MAX_LENGTH) and use it this for
* hash identification in WinPR.
*/
nla->identity->PasswordLength += LB_PASSWORD_MAX_LENGTH;
usePassword = FALSE;
}
}
if (usePassword)
{
if (!identity_set_from_settings(nla->identity, settings, FreeRDP_Username,
FreeRDP_Domain, FreeRDP_Password))
return FALSE;
}
}
return TRUE;
}
static int nla_client_init(rdpNla* nla)
{
WINPR_ASSERT(nla);
WINPR_ASSERT(nla->rdpcontext);
rdpSettings* settings = nla->rdpcontext->settings;
WINPR_ASSERT(settings);
nla_set_state(nla, NLA_STATE_INITIAL);
if (!nla_adjust_settings_from_smartcard(nla))
return -1;
if (!credssp_auth_init(nla->auth, NLA_AUTH_PKG, NULL))
return -1;
if (!nla_client_setup_identity(nla))
return -1;
const char* hostname = freerdp_settings_get_server_name(settings);
if (!credssp_auth_setup_client(nla->auth, "TERMSRV", hostname, nla->identity, nla->pkinitArgs))
return -1;
const BYTE* data = NULL;
DWORD length = 0;
if (!transport_get_public_key(nla->transport, &data, &length))
{
WLog_ERR(TAG, "Failed to get public key");
return -1;
}
if (!nla_sec_buffer_alloc_from_data(&nla->PublicKey, data, 0, length))
{
WLog_ERR(TAG, "Failed to allocate sspi secBuffer");
return -1;
}
return 1;
}
int nla_client_begin(rdpNla* nla)
{
WINPR_ASSERT(nla);
if (nla_client_init(nla) < 1)
return -1;
if (nla_get_state(nla) != NLA_STATE_INITIAL)
return -1;
/*
* from tspkg.dll: 0x00000132
* ISC_REQ_MUTUAL_AUTH
* ISC_REQ_CONFIDENTIALITY
* ISC_REQ_USE_SESSION_KEY
* ISC_REQ_ALLOCATE_MEMORY
*/
credssp_auth_set_flags(nla->auth, ISC_REQ_MUTUAL_AUTH | ISC_REQ_CONFIDENTIALITY);
const int rc = credssp_auth_authenticate(nla->auth);
switch (rc)
{
case 0:
if (!nla_send(nla))
return -1;
nla_set_state(nla, NLA_STATE_NEGO_TOKEN);
break;
case 1:
if (credssp_auth_have_output_token(nla->auth))
{
if (!nla_send(nla))
return -1;
}
nla_set_state(nla, NLA_STATE_FINAL);
break;
default:
return -1;
}
return 1;
}
static int nla_client_recv_nego_token(rdpNla* nla)
{
credssp_auth_take_input_buffer(nla->auth, &nla->negoToken);
const int rc = credssp_auth_authenticate(nla->auth);
switch (rc)
{
case 0:
if (!nla_send(nla))
return -1;
break;
case 1: /* completed */
{
int res = -1;
if (nla->peerVersion < 5)
res = nla_encrypt_public_key_echo(nla);
else
res = nla_encrypt_public_key_hash(nla);
if (!res)
return -1;
if (!nla_send(nla))
return -1;
nla_set_state(nla, NLA_STATE_PUB_KEY_AUTH);
}
break;
default:
return -1;
}
return 1;
}
static int nla_client_recv_pub_key_auth(rdpNla* nla)
{
BOOL rc = FALSE;
WINPR_ASSERT(nla);
/* Verify Server Public Key Echo */
if (nla->peerVersion < 5)
rc = nla_decrypt_public_key_echo(nla);
else
rc = nla_decrypt_public_key_hash(nla);
sspi_SecBufferFree(&nla->pubKeyAuth);
if (!rc)
return -1;
/* Send encrypted credentials */
rc = nla_encrypt_ts_credentials(nla);
if (!rc)
return -1;
if (!nla_send(nla))
return -1;
if (nla->earlyUserAuth)
{
transport_set_early_user_auth_mode(nla->transport, TRUE);
nla_set_state(nla, NLA_STATE_EARLY_USER_AUTH);
}
else
nla_set_state(nla, NLA_STATE_AUTH_INFO);
return 1;
}
static int nla_client_recv_early_user_auth(rdpNla* nla)
{
WINPR_ASSERT(nla);
transport_set_early_user_auth_mode(nla->transport, FALSE);
nla_set_state(nla, NLA_STATE_AUTH_INFO);
return 1;
}
static int nla_client_recv(rdpNla* nla)
{
WINPR_ASSERT(nla);
switch (nla_get_state(nla))
{
case NLA_STATE_NEGO_TOKEN:
return nla_client_recv_nego_token(nla);
case NLA_STATE_PUB_KEY_AUTH:
return nla_client_recv_pub_key_auth(nla);
case NLA_STATE_EARLY_USER_AUTH:
return nla_client_recv_early_user_auth(nla);
case NLA_STATE_FINAL:
default:
WLog_ERR(TAG, "NLA in invalid client receive state %s",
nla_get_state_str(nla_get_state(nla)));
return -1;
}
}
static int nla_client_authenticate(rdpNla* nla)
{
int rc = -1;
WINPR_ASSERT(nla);
wStream* s = Stream_New(NULL, 4096);
if (!s)
{
WLog_ERR(TAG, "Stream_New failed!");
return -1;
}
if (nla_client_begin(nla) < 1)
goto fail;
while (nla_get_state(nla) < NLA_STATE_AUTH_INFO)
{
Stream_SetPosition(s, 0);
const int status = transport_read_pdu(nla->transport, s);
if (status < 0)
{
WLog_ERR(TAG, "nla_client_authenticate failure");
goto fail;
}
const int status2 = nla_recv_pdu(nla, s);
if (status2 < 0)
goto fail;
}
rc = 1;
fail:
Stream_Free(s, TRUE);
return rc;
}
/**
* Initialize NTLMSSP authentication module (server).
*/
static int nla_server_init(rdpNla* nla)
{
WINPR_ASSERT(nla);
const BYTE* data = NULL;
DWORD length = 0;
if (!transport_get_public_key(nla->transport, &data, &length))
{
WLog_ERR(TAG, "Failed to get public key");
return -1;
}
if (!nla_sec_buffer_alloc_from_data(&nla->PublicKey, data, 0, length))
{
WLog_ERR(TAG, "Failed to allocate SecBuffer for public key");
return -1;
}
if (!credssp_auth_init(nla->auth, NLA_AUTH_PKG, NULL))
return -1;
if (!credssp_auth_setup_server(nla->auth))
return -1;
nla_set_state(nla, NLA_STATE_INITIAL);
return 1;
}
static wStream* nla_server_recv_stream(rdpNla* nla)
{
wStream* s = NULL;
int status = -1;
WINPR_ASSERT(nla);
s = Stream_New(NULL, 4096);
if (!s)
goto fail;
status = transport_read_pdu(nla->transport, s);
fail:
if (status < 0)
{
WLog_ERR(TAG, "nla_recv() error: %d", status);
Stream_Free(s, TRUE);
return NULL;
}
return s;
}
static BOOL nla_server_recv_credentials(rdpNla* nla)
{
WINPR_ASSERT(nla);
if (nla_server_recv(nla) < 0)
return FALSE;
if (!nla_decrypt_ts_credentials(nla))
return FALSE;
if (!nla_impersonate(nla))
return FALSE;
if (!nla_revert_to_self(nla))
return FALSE;
return TRUE;
}
/**
* Authenticate with client using CredSSP (server).
* @param nla The NLA instance to use
*
* @return 1 if authentication is successful
*/
static int nla_server_authenticate(rdpNla* nla)
{
int ret = -1;
WINPR_ASSERT(nla);
if (nla_server_init(nla) < 1)
goto fail;
/*
* from tspkg.dll: 0x00000112
* ASC_REQ_MUTUAL_AUTH
* ASC_REQ_CONFIDENTIALITY
* ASC_REQ_ALLOCATE_MEMORY
*/
credssp_auth_set_flags(nla->auth, ASC_REQ_MUTUAL_AUTH | ASC_REQ_CONFIDENTIALITY |
ASC_REQ_CONNECTION | ASC_REQ_USE_SESSION_KEY |
ASC_REQ_SEQUENCE_DETECT | ASC_REQ_EXTENDED_ERROR);
/* Client is starting, here es the state machine:
*
* -- NLA_STATE_INITIAL --> NLA_STATE_INITIAL
* ----->> sending...
* ----->> protocol version 6
* ----->> nego token
* ----->> client nonce
* <<----- receiving...
* <<----- protocol version 6
* <<----- nego token
* ----->> sending...
* ----->> protocol version 6
* ----->> nego token
* ----->> public key auth
* ----->> client nonce
* -- NLA_STATE_NEGO_TOKEN --> NLA_STATE_PUB_KEY_AUTH
* <<----- receiving...
* <<----- protocol version 6
* <<----- public key info
* ----->> sending...
* ----->> protocol version 6
* ----->> auth info
* ----->> client nonce
* -- NLA_STATE_PUB_KEY_AUTH --> NLA_STATE
*/
while (TRUE)
{
int res = -1;
if (nla_server_recv(nla) < 0)
goto fail;
WLog_DBG(TAG, "Receiving Authentication Token");
credssp_auth_take_input_buffer(nla->auth, &nla->negoToken);
res = credssp_auth_authenticate(nla->auth);
if (res == -1)
{
/* Special handling of these specific error codes as NTSTATUS_FROM_WIN32
unfortunately does not map directly to the corresponding NTSTATUS values
*/
switch (GetLastError())
{
case ERROR_PASSWORD_MUST_CHANGE:
nla->errorCode = STATUS_PASSWORD_MUST_CHANGE;
break;
case ERROR_PASSWORD_EXPIRED:
nla->errorCode = STATUS_PASSWORD_EXPIRED;
break;
case ERROR_ACCOUNT_DISABLED:
nla->errorCode = STATUS_ACCOUNT_DISABLED;
break;
default:
nla->errorCode = NTSTATUS_FROM_WIN32(GetLastError());
break;
}
nla_send(nla);
/* Access Denied */
goto fail;
}
if (res == 1)
{
/* Process final part of the nego token exchange */
if (credssp_auth_have_output_token(nla->auth))
{
if (!nla_send(nla))
goto fail;
if (nla_server_recv(nla) < 0)
goto fail;
WLog_DBG(TAG, "Receiving pubkey Token");
}
if (nla->peerVersion < 5)
res = nla_decrypt_public_key_echo(nla);
else
res = nla_decrypt_public_key_hash(nla);
if (!res)
goto fail;
/* Clear nego token buffer or we will send it again to the client */
sspi_SecBufferFree(&nla->negoToken);
if (nla->peerVersion < 5)
res = nla_encrypt_public_key_echo(nla);
else
res = nla_encrypt_public_key_hash(nla);
if (!res)
goto fail;
}
/* send authentication token */
WLog_DBG(TAG, "Sending Authentication Token");
if (!nla_send(nla))
goto fail;
if (res == 1)
{
ret = 1;
break;
}
}
/* Receive encrypted credentials */
if (!nla_server_recv_credentials(nla))
ret = -1;
fail:
nla_buffer_free(nla);
return ret;
}
/**
* Authenticate using CredSSP.
* @param nla The NLA instance to use
*
* @return 1 if authentication is successful
*/
int nla_authenticate(rdpNla* nla)
{
WINPR_ASSERT(nla);
if (nla->server)
return nla_server_authenticate(nla);
else
return nla_client_authenticate(nla);
}
static void ap_integer_increment_le(BYTE* number, size_t size)
{
WINPR_ASSERT(number || (size == 0));
for (size_t index = 0; index < size; index++)
{
if (number[index] < 0xFF)
{
number[index]++;
break;
}
else
{
number[index] = 0;
continue;
}
}
}
static void ap_integer_decrement_le(BYTE* number, size_t size)
{
WINPR_ASSERT(number || (size == 0));
for (size_t index = 0; index < size; index++)
{
if (number[index] > 0)
{
number[index]--;
break;
}
else
{
number[index] = 0xFF;
continue;
}
}
}
BOOL nla_encrypt_public_key_echo(rdpNla* nla)
{
BOOL status = FALSE;
WINPR_ASSERT(nla);
sspi_SecBufferFree(&nla->pubKeyAuth);
if (nla->server)
{
SecBuffer buf = { 0 };
if (!sspi_SecBufferAlloc(&buf, nla->PublicKey.cbBuffer))
return FALSE;
ap_integer_increment_le(buf.pvBuffer, buf.cbBuffer);
status = credssp_auth_encrypt(nla->auth, &buf, &nla->pubKeyAuth, NULL, nla->sendSeqNum++);
sspi_SecBufferFree(&buf);
}
else
{
status = credssp_auth_encrypt(nla->auth, &nla->PublicKey, &nla->pubKeyAuth, NULL,
nla->sendSeqNum++);
}
return status;
}
BOOL nla_encrypt_public_key_hash(rdpNla* nla)
{
BOOL status = FALSE;
WINPR_DIGEST_CTX* sha256 = NULL;
SecBuffer buf = { 0 };
WINPR_ASSERT(nla);
const BYTE* hashMagic = nla->server ? ServerClientHashMagic : ClientServerHashMagic;
const size_t hashSize =
nla->server ? sizeof(ServerClientHashMagic) : sizeof(ClientServerHashMagic);
if (!sspi_SecBufferAlloc(&buf, WINPR_SHA256_DIGEST_LENGTH))
return FALSE;
/* generate SHA256 of following data: ClientServerHashMagic, Nonce, SubjectPublicKey */
if (!(sha256 = winpr_Digest_New()))
goto out;
if (!winpr_Digest_Init(sha256, WINPR_MD_SHA256))
goto out;
/* include trailing \0 from hashMagic */
if (!winpr_Digest_Update(sha256, hashMagic, hashSize))
goto out;
if (!nla_Digest_Update_From_SecBuffer(sha256, &nla->ClientNonce))
goto out;
/* SubjectPublicKey */
if (!nla_Digest_Update_From_SecBuffer(sha256, &nla->PublicKey))
goto out;
if (!winpr_Digest_Final(sha256, buf.pvBuffer, WINPR_SHA256_DIGEST_LENGTH))
goto out;
sspi_SecBufferFree(&nla->pubKeyAuth);
if (!credssp_auth_encrypt(nla->auth, &buf, &nla->pubKeyAuth, NULL, nla->sendSeqNum++))
goto out;
status = TRUE;
out:
winpr_Digest_Free(sha256);
sspi_SecBufferFree(&buf);
return status;
}
BOOL nla_decrypt_public_key_echo(rdpNla* nla)
{
BOOL status = FALSE;
SecBuffer public_key = { 0 };
if (!nla)
goto fail;
if (!credssp_auth_decrypt(nla->auth, &nla->pubKeyAuth, &public_key, nla->recvSeqNum++))
return FALSE;
if (!nla->server)
{
/* server echos the public key +1 */
ap_integer_decrement_le(public_key.pvBuffer, public_key.cbBuffer);
}
if (public_key.cbBuffer != nla->PublicKey.cbBuffer ||
memcmp(public_key.pvBuffer, nla->PublicKey.pvBuffer, public_key.cbBuffer) != 0)
{
WLog_ERR(TAG, "Could not verify server's public key echo");
#if defined(WITH_DEBUG_NLA)
WLog_ERR(TAG, "Expected (length = %" PRIu32 "):", nla->PublicKey.cbBuffer);
winpr_HexDump(TAG, WLOG_ERROR, nla->PublicKey.pvBuffer, nla->PublicKey.cbBuffer);
WLog_ERR(TAG, "Actual (length = %" PRIu32 "):", public_key.cbBuffer);
winpr_HexDump(TAG, WLOG_ERROR, public_key.pvBuffer, public_key.cbBuffer);
#endif
/* DO NOT SEND CREDENTIALS! */
goto fail;
}
status = TRUE;
fail:
sspi_SecBufferFree(&public_key);
return status;
}
BOOL nla_decrypt_public_key_hash(rdpNla* nla)
{
WINPR_DIGEST_CTX* sha256 = NULL;
BYTE serverClientHash[WINPR_SHA256_DIGEST_LENGTH] = { 0 };
BOOL status = FALSE;
WINPR_ASSERT(nla);
const BYTE* hashMagic = nla->server ? ClientServerHashMagic : ServerClientHashMagic;
const size_t hashSize =
nla->server ? sizeof(ClientServerHashMagic) : sizeof(ServerClientHashMagic);
SecBuffer hash = { 0 };
if (!credssp_auth_decrypt(nla->auth, &nla->pubKeyAuth, &hash, nla->recvSeqNum++))
return FALSE;
/* generate SHA256 of following data: ServerClientHashMagic, Nonce, SubjectPublicKey */
if (!(sha256 = winpr_Digest_New()))
goto fail;
if (!winpr_Digest_Init(sha256, WINPR_MD_SHA256))
goto fail;
/* include trailing \0 from hashMagic */
if (!winpr_Digest_Update(sha256, hashMagic, hashSize))
goto fail;
if (!nla_Digest_Update_From_SecBuffer(sha256, &nla->ClientNonce))
goto fail;
/* SubjectPublicKey */
if (!nla_Digest_Update_From_SecBuffer(sha256, &nla->PublicKey))
goto fail;
if (!winpr_Digest_Final(sha256, serverClientHash, sizeof(serverClientHash)))
goto fail;
/* verify hash */
if (hash.cbBuffer != WINPR_SHA256_DIGEST_LENGTH ||
memcmp(serverClientHash, hash.pvBuffer, WINPR_SHA256_DIGEST_LENGTH) != 0)
{
WLog_ERR(TAG, "Could not verify server's hash");
/* DO NOT SEND CREDENTIALS! */
goto fail;
}
status = TRUE;
fail:
winpr_Digest_Free(sha256);
sspi_SecBufferFree(&hash);
return status;
}
static BOOL set_creds_octetstring_to_settings(WinPrAsn1Decoder* dec, WinPrAsn1_tagId tagId,
BOOL optional, FreeRDP_Settings_Keys_String settingId,
rdpSettings* settings)
{
if (optional)
{
WinPrAsn1_tagId itemTag = 0;
if (!WinPrAsn1DecPeekTag(dec, &itemTag) || (itemTag != tagId))
return TRUE;
}
BOOL error = FALSE;
WinPrAsn1_OctetString value;
/* note: not checking "error" value, as the not present optional item case is handled above
* if the function fails it's because of a real error not because the item is not present
*/
if (!WinPrAsn1DecReadContextualOctetString(dec, tagId, &error, &value, FALSE))
return FALSE;
return freerdp_settings_set_string_from_utf16N(settings, settingId, (const WCHAR*)value.data,
value.len / sizeof(WCHAR));
}
static BOOL nla_read_TSCspDataDetail(WinPrAsn1Decoder* dec, rdpSettings* settings)
{
BOOL error = FALSE;
/* keySpec [0] INTEGER */
WinPrAsn1_INTEGER keyspec = 0;
if (!WinPrAsn1DecReadContextualInteger(dec, 0, &error, &keyspec))
return FALSE;
settings->KeySpec = (UINT32)keyspec;
/* cardName [1] OCTET STRING OPTIONAL */
if (!set_creds_octetstring_to_settings(dec, 1, TRUE, FreeRDP_CardName, settings))
return FALSE;
/* readerName [2] OCTET STRING OPTIONAL */
if (!set_creds_octetstring_to_settings(dec, 2, TRUE, FreeRDP_ReaderName, settings))
return FALSE;
/* containerName [3] OCTET STRING OPTIONAL */
if (!set_creds_octetstring_to_settings(dec, 3, TRUE, FreeRDP_ContainerName, settings))
return FALSE;
/* cspName [4] OCTET STRING OPTIONAL */
return set_creds_octetstring_to_settings(dec, 4, TRUE, FreeRDP_CspName, settings);
}
static BOOL nla_read_KERB_TICKET_LOGON(rdpNla* nla, wStream* s, KERB_TICKET_LOGON* ticket)
{
WINPR_ASSERT(nla);
if (!ticket)
return FALSE;
/* mysterious extra 16 bytes before TGS/TGT content */
if (!Stream_CheckAndLogRequiredLength(TAG, s, 16 + 16))
return FALSE;
Stream_Read_UINT32(s, ticket->MessageType);
Stream_Read_UINT32(s, ticket->Flags);
Stream_Read_UINT32(s, ticket->ServiceTicketLength);
Stream_Read_UINT32(s, ticket->TicketGrantingTicketLength);
if (ticket->MessageType != KerbTicketLogon)
{
WLog_ERR(TAG, "Not a KerbTicketLogon");
return FALSE;
}
if (!Stream_CheckAndLogRequiredLength(
TAG, s, 16ull + ticket->ServiceTicketLength + ticket->TicketGrantingTicketLength))
return FALSE;
/* mysterious 16 bytes in the way, maybe they would need to be interpreted... */
Stream_Seek(s, 16);
/*WLog_INFO(TAG, "TGS");
winpr_HexDump(TAG, WLOG_DEBUG, Stream_PointerAs(s, const BYTE), ticket->ServiceTicketLength);*/
ticket->ServiceTicket = Stream_PointerAs(s, UCHAR);
Stream_Seek(s, ticket->ServiceTicketLength);
/*WLog_INFO(TAG, "TGT");
winpr_HexDump(TAG, WLOG_DEBUG, Stream_PointerAs(s, const BYTE),
ticket->TicketGrantingTicketLength);*/
ticket->TicketGrantingTicket = Stream_PointerAs(s, UCHAR);
return TRUE;
}
/** @brief kind of RCG credentials */
typedef enum
{
RCG_TYPE_KERB,
RCG_TYPE_NTLM
} RemoteGuardPackageCredType;
static BOOL nla_read_TSRemoteGuardPackageCred(rdpNla* nla, WinPrAsn1Decoder* dec,
RemoteGuardPackageCredType* credsType,
wStream* payload)
{
WinPrAsn1_OctetString packageName = { 0 };
WinPrAsn1_OctetString credBuffer = { 0 };
BOOL error = FALSE;
char packageNameStr[100] = { 0 };
/* packageName [0] OCTET STRING */
if (!WinPrAsn1DecReadContextualOctetString(dec, 0, &error, &packageName, FALSE) || error)
return TRUE;
ConvertMszWCharNToUtf8((WCHAR*)packageName.data, packageName.len / sizeof(WCHAR),
packageNameStr, 100);
WLog_DBG(TAG, "TSRemoteGuardPackageCred(%s)", packageNameStr);
/* credBuffer [1] OCTET STRING, */
if (!WinPrAsn1DecReadContextualOctetString(dec, 1, &error, &credBuffer, FALSE) || error)
return TRUE;
if (_stricmp(packageNameStr, "Kerberos") == 0)
{
*credsType = RCG_TYPE_KERB;
}
else if (_stricmp(packageNameStr, "NTLM") == 0)
{
*credsType = RCG_TYPE_NTLM;
}
else
{
WLog_INFO(TAG, "TSRemoteGuardPackageCred package %s not handled", packageNameStr);
return FALSE;
}
Stream_StaticInit(payload, credBuffer.data, credBuffer.len);
return TRUE;
}
/** @brief kind of TSCreds */
typedef enum
{
TSCREDS_INVALID = 0,
TSCREDS_USER_PASSWD = 1,
TSCREDS_SMARTCARD = 2,
TSCREDS_REMOTEGUARD = 6
} TsCredentialsType;
static BOOL nla_read_ts_credentials(rdpNla* nla, SecBuffer* data)
{
WinPrAsn1Decoder dec = { 0 };
WinPrAsn1Decoder dec2 = { 0 };
WinPrAsn1_OctetString credentials = { 0 };
BOOL error = FALSE;
WinPrAsn1_INTEGER credType = -1;
BOOL ret = TRUE;
WINPR_ASSERT(nla);
WINPR_ASSERT(data);
WinPrAsn1Decoder_InitMem(&dec, WINPR_ASN1_DER, (BYTE*)data->pvBuffer, data->cbBuffer);
/* TSCredentials */
if (!WinPrAsn1DecReadSequence(&dec, &dec2))
return FALSE;
dec = dec2;
/* credType [0] INTEGER */
if (!WinPrAsn1DecReadContextualInteger(&dec, 0, &error, &credType))
return FALSE;
/* credentials [1] OCTET STRING */
if (!WinPrAsn1DecReadContextualOctetString(&dec, 1, &error, &credentials, FALSE))
return FALSE;
WinPrAsn1Decoder_InitMem(&dec, WINPR_ASN1_DER, credentials.data, credentials.len);
rdpSettings* settings = nla->rdpcontext->settings;
if (nego_get_remoteCredentialGuard(nla->rdpcontext->rdp->nego) &&
credType != TSCREDS_REMOTEGUARD)
{
WLog_ERR(TAG, "connecting with RCG but it's not TSRemoteGuard credentials");
return FALSE;
}
switch (credType)
{
case TSCREDS_USER_PASSWD:
{
/* TSPasswordCreds */
if (!WinPrAsn1DecReadSequence(&dec, &dec2))
return FALSE;
dec = dec2;
/* domainName [0] OCTET STRING */
if (!set_creds_octetstring_to_settings(&dec, 0, FALSE, FreeRDP_Domain, settings))
return FALSE;
/* userName [1] OCTET STRING */
if (!set_creds_octetstring_to_settings(&dec, 1, FALSE, FreeRDP_Username, settings))
return FALSE;
/* password [2] OCTET STRING */
return set_creds_octetstring_to_settings(&dec, 2, FALSE, FreeRDP_Password, settings);
}
case TSCREDS_SMARTCARD:
{
/* TSSmartCardCreds */
if (!WinPrAsn1DecReadSequence(&dec, &dec2))
return FALSE;
dec = dec2;
/* pin [0] OCTET STRING, */
if (!set_creds_octetstring_to_settings(&dec, 0, FALSE, FreeRDP_Password, settings))
return FALSE;
settings->PasswordIsSmartcardPin = TRUE;
/* cspData [1] TSCspDataDetail */
WinPrAsn1Decoder cspDetails = { 0 };
if (!WinPrAsn1DecReadContextualSequence(&dec, 1, &error, &cspDetails) && error)
return FALSE;
if (!nla_read_TSCspDataDetail(&cspDetails, settings))
return FALSE;
/* userHint [2] OCTET STRING OPTIONAL */
if (!set_creds_octetstring_to_settings(&dec, 2, TRUE, FreeRDP_Username, settings))
return FALSE;
/* domainHint [3] OCTET STRING OPTIONAL */
return set_creds_octetstring_to_settings(&dec, 3, TRUE, FreeRDP_Domain, settings);
}
case TSCREDS_REMOTEGUARD:
{
/* TSRemoteGuardCreds */
if (!WinPrAsn1DecReadSequence(&dec, &dec2))
return FALSE;
/* logonCred[0] TSRemoteGuardPackageCred */
KERB_TICKET_LOGON kerbLogon = { 0 };
WinPrAsn1Decoder logonCredsSeq = { 0 };
if (!WinPrAsn1DecReadContextualSequence(&dec2, 0, &error, &logonCredsSeq) || error)
return FALSE;
RemoteGuardPackageCredType logonCredsType = { 0 };
wStream logonPayload = { 0 };
if (!nla_read_TSRemoteGuardPackageCred(nla, &logonCredsSeq, &logonCredsType,
&logonPayload))
return FALSE;
if (logonCredsType != RCG_TYPE_KERB)
{
WLog_ERR(TAG, "logonCred must be some Kerberos creds");
return FALSE;
}
if (!nla_read_KERB_TICKET_LOGON(nla, &logonPayload, &kerbLogon))
{
WLog_ERR(TAG, "invalid KERB_TICKET_LOGON");
return FALSE;
}
/* supplementalCreds [1] SEQUENCE OF TSRemoteGuardPackageCred OPTIONAL, */
MSV1_0_SUPPLEMENTAL_CREDENTIAL* suppCreds = NULL;
WinPrAsn1Decoder suppCredsSeq = { 0 };
if (WinPrAsn1DecReadContextualSequence(&dec2, 1, &error, &suppCredsSeq))
{
WinPrAsn1Decoder ntlmCredsSeq = { 0 };
if (!WinPrAsn1DecReadSequence(&suppCredsSeq, &ntlmCredsSeq))
return FALSE;
RemoteGuardPackageCredType suppCredsType = { 0 };
wStream ntlmPayload = { 0 };
if (!nla_read_TSRemoteGuardPackageCred(nla, &ntlmCredsSeq, &suppCredsType,
&ntlmPayload))
return FALSE;
if (suppCredsType != RCG_TYPE_NTLM)
{
WLog_ERR(TAG, "supplementalCreds must be some NTLM creds");
return FALSE;
}
/* TODO: suppCreds = &ntlmCreds; and parse NTLM creds */
}
else if (error)
{
WLog_ERR(TAG, "invalid supplementalCreds");
return FALSE;
}
freerdp_peer* peer = nla->rdpcontext->peer;
ret = IFCALLRESULT(TRUE, peer->RemoteCredentials, peer, &kerbLogon, suppCreds);
break;
}
default:
WLog_DBG(TAG, "TSCredentials type " PRIu32 " not supported for now", credType);
ret = FALSE;
break;
}
return ret;
}
/**
* Encode TSCredentials structure.
* @param nla A pointer to the NLA to use
*
* @return \b TRUE for success, \b FALSE otherwise
*/
static BOOL nla_encode_ts_credentials(rdpNla* nla)
{
BOOL ret = FALSE;
WinPrAsn1Encoder* enc = NULL;
size_t length = 0;
wStream s = { 0 };
TsCredentialsType credType = TSCREDS_INVALID;
WINPR_ASSERT(nla);
WINPR_ASSERT(nla->rdpcontext);
rdpSettings* settings = nla->rdpcontext->settings;
WINPR_ASSERT(settings);
if (settings->RemoteCredentialGuard)
credType = TSCREDS_REMOTEGUARD;
else if (settings->SmartcardLogon)
credType = TSCREDS_SMARTCARD;
else
credType = TSCREDS_USER_PASSWD;
enc = WinPrAsn1Encoder_New(WINPR_ASN1_DER);
if (!enc)
return FALSE;
/* TSCredentials */
if (!WinPrAsn1EncSeqContainer(enc))
goto out;
/* credType [0] INTEGER */
if (!WinPrAsn1EncContextualInteger(enc, 0, (WinPrAsn1_INTEGER)credType))
goto out;
/* credentials [1] OCTET STRING */
if (!WinPrAsn1EncContextualOctetStringContainer(enc, 1))
goto out;
switch (credType)
{
case TSCREDS_SMARTCARD:
{
struct
{
WinPrAsn1_tagId tag;
size_t setting_id;
} cspData_fields[] = { { 1, FreeRDP_CardName },
{ 2, FreeRDP_ReaderName },
{ 3, FreeRDP_ContainerName },
{ 4, FreeRDP_CspName } };
WinPrAsn1_OctetString octet_string = { 0 };
/* TSSmartCardCreds */
if (!WinPrAsn1EncSeqContainer(enc))
goto out;
/* pin [0] OCTET STRING */
size_t ss = 0;
octet_string.data =
(BYTE*)freerdp_settings_get_string_as_utf16(settings, FreeRDP_Password, &ss);
octet_string.len = ss * sizeof(WCHAR);
const BOOL res = WinPrAsn1EncContextualOctetString(enc, 0, &octet_string) > 0;
free(octet_string.data);
if (!res)
goto out;
/* cspData [1] SEQUENCE */
if (!WinPrAsn1EncContextualSeqContainer(enc, 1))
goto out;
/* keySpec [0] INTEGER */
if (!WinPrAsn1EncContextualInteger(
enc, 0, freerdp_settings_get_uint32(settings, FreeRDP_KeySpec)))
goto out;
for (size_t i = 0; i < ARRAYSIZE(cspData_fields); i++)
{
size_t len = 0;
octet_string.data = (BYTE*)freerdp_settings_get_string_as_utf16(
settings, cspData_fields[i].setting_id, &len);
octet_string.len = len * sizeof(WCHAR);
if (octet_string.len)
{
const BOOL res2 = WinPrAsn1EncContextualOctetString(enc, cspData_fields[i].tag,
&octet_string) > 0;
free(octet_string.data);
if (!res2)
goto out;
}
}
/* End cspData */
if (!WinPrAsn1EncEndContainer(enc))
goto out;
/* End TSSmartCardCreds */
if (!WinPrAsn1EncEndContainer(enc))
goto out;
break;
}
case TSCREDS_USER_PASSWD:
{
WinPrAsn1_OctetString username = { 0 };
WinPrAsn1_OctetString domain = { 0 };
WinPrAsn1_OctetString password = { 0 };
/* TSPasswordCreds */
if (!WinPrAsn1EncSeqContainer(enc))
goto out;
if (!settings->DisableCredentialsDelegation && nla->identity)
{
username.len = nla->identity->UserLength * sizeof(WCHAR);
username.data = (BYTE*)nla->identity->User;
domain.len = nla->identity->DomainLength * sizeof(WCHAR);
domain.data = (BYTE*)nla->identity->Domain;
password.len = nla->identity->PasswordLength * sizeof(WCHAR);
password.data = (BYTE*)nla->identity->Password;
}
if (WinPrAsn1EncContextualOctetString(enc, 0, &domain) == 0)
goto out;
if (WinPrAsn1EncContextualOctetString(enc, 1, &username) == 0)
goto out;
if (WinPrAsn1EncContextualOctetString(enc, 2, &password) == 0)
goto out;
/* End TSPasswordCreds */
if (!WinPrAsn1EncEndContainer(enc))
goto out;
break;
}
case TSCREDS_REMOTEGUARD:
default:
goto out;
}
/* End credentials | End TSCredentials */
if (!WinPrAsn1EncEndContainer(enc) || !WinPrAsn1EncEndContainer(enc))
goto out;
if (!WinPrAsn1EncStreamSize(enc, &length))
goto out;
if (!nla_sec_buffer_alloc(&nla->tsCredentials, length))
{
WLog_ERR(TAG, "sspi_SecBufferAlloc failed!");
goto out;
}
Stream_StaticInit(&s, (BYTE*)nla->tsCredentials.pvBuffer, length);
ret = WinPrAsn1EncToStream(enc, &s);
out:
WinPrAsn1Encoder_Free(&enc);
return ret;
}
static BOOL nla_encrypt_ts_credentials(rdpNla* nla)
{
WINPR_ASSERT(nla);
if (!nla_encode_ts_credentials(nla))
return FALSE;
sspi_SecBufferFree(&nla->authInfo);
if (!credssp_auth_encrypt(nla->auth, &nla->tsCredentials, &nla->authInfo, NULL,
nla->sendSeqNum++))
return FALSE;
return TRUE;
}
static BOOL nla_decrypt_ts_credentials(rdpNla* nla)
{
WINPR_ASSERT(nla);
if (nla->authInfo.cbBuffer < 1)
{
WLog_ERR(TAG, "nla_decrypt_ts_credentials missing authInfo buffer");
return FALSE;
}
sspi_SecBufferFree(&nla->tsCredentials);
if (!credssp_auth_decrypt(nla->auth, &nla->authInfo, &nla->tsCredentials, nla->recvSeqNum++))
return FALSE;
if (!nla_read_ts_credentials(nla, &nla->tsCredentials))
return FALSE;
return TRUE;
}
static BOOL nla_write_octet_string(WinPrAsn1Encoder* enc, const SecBuffer* buffer,
WinPrAsn1_tagId tagId, const char* msg)
{
BOOL res = FALSE;
WINPR_ASSERT(enc);
WINPR_ASSERT(buffer);
WINPR_ASSERT(msg);
if (buffer->cbBuffer > 0)
{
size_t rc = 0;
WinPrAsn1_OctetString octet_string = { 0 };
WLog_DBG(TAG, " ----->> %s", msg);
octet_string.data = buffer->pvBuffer;
octet_string.len = buffer->cbBuffer;
rc = WinPrAsn1EncContextualOctetString(enc, tagId, &octet_string);
if (rc != 0)
res = TRUE;
}
return res;
}
static BOOL nla_write_octet_string_free(WinPrAsn1Encoder* enc, SecBuffer* buffer,
WinPrAsn1_tagId tagId, const char* msg)
{
const BOOL rc = nla_write_octet_string(enc, buffer, tagId, msg);
sspi_SecBufferFree(buffer);
return rc;
}
/**
* Send CredSSP message.
*
* @param nla A pointer to the NLA to use
*
* @return \b TRUE for success, \b FALSE otherwise
*/
BOOL nla_send(rdpNla* nla)
{
BOOL rc = FALSE;
wStream* s = NULL;
size_t length = 0;
WinPrAsn1Encoder* enc = NULL;
WINPR_ASSERT(nla);
enc = WinPrAsn1Encoder_New(WINPR_ASN1_DER);
if (!enc)
return FALSE;
/* TSRequest */
WLog_DBG(TAG, "----->> sending...");
if (!WinPrAsn1EncSeqContainer(enc))
goto fail;
/* version [0] INTEGER */
WLog_DBG(TAG, " ----->> protocol version %" PRIu32, nla->version);
if (!WinPrAsn1EncContextualInteger(enc, 0, nla->version))
goto fail;
/* negoTokens [1] SEQUENCE OF SEQUENCE */
if (nla_get_state(nla) <= NLA_STATE_NEGO_TOKEN && credssp_auth_have_output_token(nla->auth))
{
const SecBuffer* buffer = credssp_auth_get_output_buffer(nla->auth);
if (!WinPrAsn1EncContextualSeqContainer(enc, 1) || !WinPrAsn1EncSeqContainer(enc))
goto fail;
/* negoToken [0] OCTET STRING */
if (!nla_write_octet_string(enc, buffer, 0, "negoToken"))
goto fail;
/* End negoTokens (SEQUENCE OF SEQUENCE) */
if (!WinPrAsn1EncEndContainer(enc) || !WinPrAsn1EncEndContainer(enc))
goto fail;
}
/* authInfo [2] OCTET STRING */
if (nla->authInfo.cbBuffer > 0)
{
if (!nla_write_octet_string_free(enc, &nla->authInfo, 2, "auth info"))
goto fail;
}
/* pubKeyAuth [3] OCTET STRING */
if (nla->pubKeyAuth.cbBuffer > 0)
{
if (!nla_write_octet_string_free(enc, &nla->pubKeyAuth, 3, "public key auth"))
goto fail;
}
/* errorCode [4] INTEGER */
if (nla->errorCode && nla->peerVersion >= 3 && nla->peerVersion != 5)
{
WLog_DBG(TAG, " ----->> error code %s 0x%08" PRIx32, NtStatus2Tag(nla->errorCode),
nla->errorCode);
if (!WinPrAsn1EncContextualInteger(enc, 4, nla->errorCode))
goto fail;
}
/* clientNonce [5] OCTET STRING */
if (!nla->server && nla->ClientNonce.cbBuffer > 0)
{
if (!nla_write_octet_string(enc, &nla->ClientNonce, 5, "client nonce"))
goto fail;
}
/* End TSRequest */
if (!WinPrAsn1EncEndContainer(enc))
goto fail;
if (!WinPrAsn1EncStreamSize(enc, &length))
goto fail;
s = Stream_New(NULL, length);
if (!s)
goto fail;
if (!WinPrAsn1EncToStream(enc, s))
goto fail;
WLog_DBG(TAG, "[%" PRIuz " bytes]", length);
if (transport_write(nla->transport, s) < 0)
goto fail;
rc = TRUE;
fail:
Stream_Free(s, TRUE);
WinPrAsn1Encoder_Free(&enc);
return rc;
}
static int nla_decode_ts_request(rdpNla* nla, wStream* s)
{
WinPrAsn1Decoder dec = { 0 };
WinPrAsn1Decoder dec2 = { 0 };
BOOL error = FALSE;
WinPrAsn1_tagId tag = { 0 };
WinPrAsn1_INTEGER val = { 0 };
UINT32 version = 0;
WINPR_ASSERT(nla);
WINPR_ASSERT(s);
WinPrAsn1Decoder_Init(&dec, WINPR_ASN1_DER, s);
WLog_DBG(TAG, "<<----- receiving...");
/* TSRequest */
const size_t offset = WinPrAsn1DecReadSequence(&dec, &dec2);
if (offset == 0)
return -1;
dec = dec2;
/* version [0] INTEGER */
if (WinPrAsn1DecReadContextualInteger(&dec, 0, &error, &val) == 0)
return -1;
if (!Stream_SafeSeek(s, offset))
return -1;
version = (UINT)val;
WLog_DBG(TAG, " <<----- protocol version %" PRIu32, version);
if (nla->peerVersion == 0)
nla->peerVersion = version;
/* if the peer suddenly changed its version - kick it */
if (nla->peerVersion != version)
{
WLog_ERR(TAG, "CredSSP peer changed protocol version from %" PRIu32 " to %" PRIu32,
nla->peerVersion, version);
return -1;
}
while (WinPrAsn1DecReadContextualTag(&dec, &tag, &dec2) != 0)
{
WinPrAsn1Decoder dec3 = { 0 };
WinPrAsn1_OctetString octet_string = { 0 };
switch (tag)
{
case 1:
WLog_DBG(TAG, " <<----- nego token");
/* negoTokens [1] SEQUENCE OF SEQUENCE */
if ((WinPrAsn1DecReadSequence(&dec2, &dec3) == 0) ||
(WinPrAsn1DecReadSequence(&dec3, &dec2) == 0))
return -1;
/* negoToken [0] OCTET STRING */
if ((WinPrAsn1DecReadContextualOctetString(&dec2, 0, &error, &octet_string,
FALSE) == 0) &&
error)
return -1;
if (!nla_sec_buffer_alloc_from_data(&nla->negoToken, octet_string.data, 0,
octet_string.len))
return -1;
break;
case 2:
WLog_DBG(TAG, " <<----- auth info");
/* authInfo [2] OCTET STRING */
if (WinPrAsn1DecReadOctetString(&dec2, &octet_string, FALSE) == 0)
return -1;
if (!nla_sec_buffer_alloc_from_data(&nla->authInfo, octet_string.data, 0,
octet_string.len))
return -1;
break;
case 3:
WLog_DBG(TAG, " <<----- public key auth");
/* pubKeyAuth [3] OCTET STRING */
if (WinPrAsn1DecReadOctetString(&dec2, &octet_string, FALSE) == 0)
return -1;
if (!nla_sec_buffer_alloc_from_data(&nla->pubKeyAuth, octet_string.data, 0,
octet_string.len))
return -1;
break;
case 4:
/* errorCode [4] INTEGER */
if (WinPrAsn1DecReadInteger(&dec2, &val) == 0)
return -1;
nla->errorCode = (UINT)val;
WLog_DBG(TAG, " <<----- error code %s 0x%08" PRIx32, NtStatus2Tag(nla->errorCode),
nla->errorCode);
break;
case 5:
WLog_DBG(TAG, " <<----- client nonce");
/* clientNonce [5] OCTET STRING */
if (WinPrAsn1DecReadOctetString(&dec2, &octet_string, FALSE) == 0)
return -1;
if (!nla_sec_buffer_alloc_from_data(&nla->ClientNonce, octet_string.data, 0,
octet_string.len))
return -1;
break;
default:
return -1;
}
}
return 1;
}
int nla_recv_pdu(rdpNla* nla, wStream* s)
{
WINPR_ASSERT(nla);
WINPR_ASSERT(s);
if (nla_get_state(nla) == NLA_STATE_EARLY_USER_AUTH)
{
UINT32 code = 0;
Stream_Read_UINT32(s, code);
if (code != AUTHZ_SUCCESS)
{
WLog_DBG(TAG, "Early User Auth active: FAILURE code 0x%08" PRIX32 "", code);
code = FREERDP_ERROR_AUTHENTICATION_FAILED;
freerdp_set_last_error_log(nla->rdpcontext, code);
return -1;
}
else
WLog_DBG(TAG, "Early User Auth active: SUCCESS");
}
else
{
if (nla_decode_ts_request(nla, s) < 1)
return -1;
if (nla->errorCode)
{
UINT32 code = 0;
switch (nla->errorCode)
{
case STATUS_PASSWORD_MUST_CHANGE:
code = FREERDP_ERROR_CONNECT_PASSWORD_MUST_CHANGE;
break;
case STATUS_PASSWORD_EXPIRED:
code = FREERDP_ERROR_CONNECT_PASSWORD_EXPIRED;
break;
case STATUS_ACCOUNT_DISABLED:
code = FREERDP_ERROR_CONNECT_ACCOUNT_DISABLED;
break;
case STATUS_LOGON_FAILURE:
code = FREERDP_ERROR_CONNECT_LOGON_FAILURE;
break;
case STATUS_WRONG_PASSWORD:
code = FREERDP_ERROR_CONNECT_WRONG_PASSWORD;
break;
case STATUS_ACCESS_DENIED:
code = FREERDP_ERROR_CONNECT_ACCESS_DENIED;
break;
case STATUS_ACCOUNT_RESTRICTION:
code = FREERDP_ERROR_CONNECT_ACCOUNT_RESTRICTION;
break;
case STATUS_ACCOUNT_LOCKED_OUT:
code = FREERDP_ERROR_CONNECT_ACCOUNT_LOCKED_OUT;
break;
case STATUS_ACCOUNT_EXPIRED:
code = FREERDP_ERROR_CONNECT_ACCOUNT_EXPIRED;
break;
case STATUS_LOGON_TYPE_NOT_GRANTED:
code = FREERDP_ERROR_CONNECT_LOGON_TYPE_NOT_GRANTED;
break;
default:
WLog_ERR(TAG, "SPNEGO failed with NTSTATUS: %s [0x%08" PRIX32 "]",
NtStatus2Tag(nla->errorCode), nla->errorCode);
code = FREERDP_ERROR_AUTHENTICATION_FAILED;
break;
}
freerdp_set_last_error_log(nla->rdpcontext, code);
return -1;
}
}
return nla_client_recv(nla);
}
int nla_server_recv(rdpNla* nla)
{
int status = -1;
WINPR_ASSERT(nla);
wStream* s = nla_server_recv_stream(nla);
if (!s)
goto fail;
status = nla_decode_ts_request(nla, s);
fail:
Stream_Free(s, TRUE);
return status;
}
/**
* Create new CredSSP state machine.
*
* @param context A pointer to the rdp context to use
* @param transport A pointer to the transport to use
*
* @return new CredSSP state machine.
*/
rdpNla* nla_new(rdpContext* context, rdpTransport* transport)
{
WINPR_ASSERT(transport);
WINPR_ASSERT(context);
rdpSettings* settings = context->settings;
WINPR_ASSERT(settings);
rdpNla* nla = (rdpNla*)calloc(1, sizeof(rdpNla));
if (!nla)
return NULL;
nla->rdpcontext = context;
nla->server = settings->ServerMode;
nla->transport = transport;
nla->sendSeqNum = 0;
nla->recvSeqNum = 0;
nla->version = 6;
nla->earlyUserAuth = FALSE;
nla->identity = calloc(1, sizeof(SEC_WINNT_AUTH_IDENTITY));
if (!nla->identity)
goto cleanup;
nla->auth = credssp_auth_new(context);
if (!nla->auth)
goto cleanup;
/* init to 0 or we end up freeing a bad pointer if the alloc fails */
if (!nla_sec_buffer_alloc(&nla->ClientNonce, NonceLength))
goto cleanup;
/* generate random 32-byte nonce */
if (winpr_RAND(nla->ClientNonce.pvBuffer, NonceLength) < 0)
goto cleanup;
return nla;
cleanup:
WINPR_PRAGMA_DIAG_PUSH
WINPR_PRAGMA_DIAG_IGNORED_MISMATCHED_DEALLOC
nla_free(nla);
WINPR_PRAGMA_DIAG_POP
return NULL;
}
/**
* Free CredSSP state machine.
* @param nla The NLA instance to free
*/
void nla_free(rdpNla* nla)
{
if (!nla)
return;
smartcardCertInfo_Free(nla->smartcardCert);
nla_buffer_free(nla);
sspi_SecBufferFree(&nla->tsCredentials);
credssp_auth_free(nla->auth);
sspi_FreeAuthIdentity(nla->identity);
free(nla->pkinitArgs);
free(nla->identity);
free(nla);
}
SEC_WINNT_AUTH_IDENTITY* nla_get_identity(rdpNla* nla)
{
if (!nla)
return NULL;
return nla->identity;
}
NLA_STATE nla_get_state(rdpNla* nla)
{
if (!nla)
return NLA_STATE_FINAL;
return nla->state;
}
BOOL nla_set_state(rdpNla* nla, NLA_STATE state)
{
if (!nla)
return FALSE;
WLog_DBG(TAG, "-- %s\t--> %s", nla_get_state_str(nla->state), nla_get_state_str(state));
nla->state = state;
return TRUE;
}
BOOL nla_set_service_principal(rdpNla* nla, const char* service, const char* hostname)
{
if (!credssp_auth_set_spn(nla->auth, service, hostname))
return FALSE;
return TRUE;
}
BOOL nla_impersonate(rdpNla* nla)
{
return credssp_auth_impersonate(nla->auth);
}
BOOL nla_revert_to_self(rdpNla* nla)
{
return credssp_auth_revert_to_self(nla->auth);
}
const char* nla_get_state_str(NLA_STATE state)
{
switch (state)
{
case NLA_STATE_INITIAL:
return "NLA_STATE_INITIAL";
case NLA_STATE_NEGO_TOKEN:
return "NLA_STATE_NEGO_TOKEN";
case NLA_STATE_PUB_KEY_AUTH:
return "NLA_STATE_PUB_KEY_AUTH";
case NLA_STATE_AUTH_INFO:
return "NLA_STATE_AUTH_INFO";
case NLA_STATE_POST_NEGO:
return "NLA_STATE_POST_NEGO";
case NLA_STATE_EARLY_USER_AUTH:
return "NLA_STATE_EARLY_USER_AUTH";
case NLA_STATE_FINAL:
return "NLA_STATE_FINAL";
default:
return "UNKNOWN";
}
}
DWORD nla_get_error(rdpNla* nla)
{
if (!nla)
return ERROR_INTERNAL_ERROR;
return nla->errorCode;
}
UINT32 nla_get_sspi_error(rdpNla* nla)
{
WINPR_ASSERT(nla);
return credssp_auth_sspi_error(nla->auth);
}
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