redirection.c

 
#include <freerdp/config.h>
 
#include "settings.h"
 
#include <winpr/crt.h>
#include <winpr/string.h>
#include <freerdp/log.h>
#include <freerdp/crypto/certificate.h>
#include <freerdp/redirection.h>
#include <freerdp/utils/string.h>
 
#include "../crypto/certificate.h"
#include "redirection.h"
#include "utils.h"
 
#define TAG FREERDP_TAG("core.redirection")
 
struct rdp_redirection
{
  UINT32 flags;
  UINT32 sessionID;
  BYTE* TsvUrl;
  UINT32 TsvUrlLength;
  char* Username;
  char* Domain;
  BYTE* Password;
  UINT32 PasswordLength;
  char* TargetFQDN;
  BYTE* LoadBalanceInfo;
  UINT32 LoadBalanceInfoLength;
  char* TargetNetBiosName;
  char* TargetNetAddress;
  UINT32 TargetNetAddressesCount;
  char** TargetNetAddresses;
  UINT32 RedirectionGuidLength;
  BYTE* RedirectionGuid;
 
  rdpCertificate* TargetCertificate;
};
 
static void redirection_free_array(char*** what, UINT32* count)
{
  WINPR_ASSERT(what);
  WINPR_ASSERT(count);
 
  if (*what)
  {
    for (UINT32 x = 0; x < *count; x++)
      free((*what)[x]);
    free((void*)*what);
  }
 
  *what = nullptr;
  *count = 0;
}
 
static void redirection_free_string(char** str)
{
  WINPR_ASSERT(str);
  free(*str);
  *str = nullptr;
}
 
static void redirection_free_data(BYTE** str, UINT32* length)
{
  WINPR_ASSERT(str);
  free(*str);
  if (length)
    *length = 0;
  *str = nullptr;
}
 
static BOOL redirection_copy_string(char** dst, const char* str)
{
  redirection_free_string(dst);
  if (!str)
    return TRUE;
 
  *dst = _strdup(str);
  return *dst != nullptr;
}
 
static BOOL redirection_copy_data(BYTE** dst, UINT32* plen, const BYTE* str, size_t len)
{
  redirection_free_data(dst, plen);
 
  if (!str || (len == 0))
    return TRUE;
  if (len > UINT32_MAX)
    return FALSE;
 
  *dst = malloc(len);
  if (!*dst)
    return FALSE;
  memcpy(*dst, str, len);
  *plen = (UINT32)len;
  return *dst != nullptr;
}
 
static BOOL redirection_copy_array(char*** dst, UINT32* plen, const char** str, size_t len)
{
  redirection_free_array(dst, plen);
 
  if (len > UINT32_MAX)
    return FALSE;
  if (!str || (len == 0))
    return TRUE;
 
  *dst = (char**)calloc(len, sizeof(char*));
  if (!*dst)
    return FALSE;
  *plen = (UINT32)len;
 
  for (size_t x = 0; x < len; x++)
  {
    if (str[x])
      (*dst)[x] = _strdup(str[x]);
 
    if (!((*dst)[x]))
    {
      redirection_free_array(dst, plen);
      return FALSE;
    }
  }
 
  return *dst != nullptr;
}
 
static BOOL rdp_redirection_get_data(wStream* s, UINT32* pLength, const BYTE** pData)
{
  WINPR_ASSERT(pLength);
  WINPR_ASSERT(pData);
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 4))
    return FALSE;
 
  Stream_Read_UINT32(s, *pLength);
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, *pLength))
    return FALSE;
 
  *pData = Stream_ConstPointer(s);
  Stream_Seek(s, *pLength);
  return TRUE;
}
 
WINPR_ATTR_NODISCARD
static BOOL rdp_redirection_read_unicode_string(wStream* s, char** str, size_t maxLength)
{
  UINT32 length = 0;
  const BYTE* data = nullptr;
 
  if (!rdp_redirection_get_data(s, &length, &data))
    return FALSE;
 
  if ((length % 2) || (length < 2) || (length > maxLength))
  {
    WLog_ERR(TAG, "failure: invalid unicode string length: %" PRIu32 "", length);
    return FALSE;
  }
 
  WCHAR wstr[513] = WINPR_C_ARRAY_INIT;
  WINPR_ASSERT(ARRAYSIZE(wstr) > maxLength);
  memcpy(wstr, data, length);
 
  if (wstr[length / 2 - 1])
  {
    WLog_ERR(TAG, "failure: unterminated unicode string");
    return FALSE;
  }
 
  redirection_free_string(str);
  *str = ConvertWCharNToUtf8Alloc(wstr, length / sizeof(WCHAR), nullptr);
  if (!*str)
  {
    WLog_ERR(TAG, "failure: string conversion failed");
    return FALSE;
  }
 
  return TRUE;
}
 
static BOOL rdp_redirection_write_data(wStream* s, size_t length, const void* data)
{
  WINPR_ASSERT(data || (length == 0));
  WINPR_ASSERT(length <= UINT32_MAX);
 
  if (!Stream_EnsureRemainingCapacity(s, 4))
    return FALSE;
 
  Stream_Write_UINT32(s, (UINT32)length);
 
  if (!Stream_EnsureRemainingCapacity(s, length))
    return FALSE;
 
  Stream_Write(s, data, length);
  return TRUE;
}
 
static BOOL rdp_redirection_write_base64_wchar(WINPR_ATTR_UNUSED UINT32 flag, wStream* s,
                                               size_t length, const void* data)
{
  BOOL rc = FALSE;
 
  size_t olen = 0;
  char* base64 = crypto_base64_encode_len(data, length, &olen);
  if (!base64)
    return FALSE;
 
  size_t wbase64len = 0;
  WCHAR* wbase64 = ConvertUtf8NToWCharAlloc(base64, olen, &wbase64len);
  free(base64);
  if (!wbase64)
    return FALSE;
 
  rc = rdp_redirection_write_data(s, wbase64len * sizeof(WCHAR), wbase64);
  free(wbase64);
  return rc;
}
 
static BOOL rdp_redirection_read_base64_wchar(UINT32 flag, wStream* s, UINT32* pLength,
                                              BYTE** pData)
{
  BOOL rc = FALSE;
  char buffer[64] = WINPR_C_ARRAY_INIT;
  const BYTE* ptr = nullptr;
 
  if (!rdp_redirection_get_data(s, pLength, &ptr))
    return FALSE;
  const WCHAR* wchar = WINPR_PACKED_ALIGN_CAST(const WCHAR*, ptr);
 
  size_t utf8_len = 0;
  char* utf8 = ConvertWCharNToUtf8Alloc(wchar, *pLength / sizeof(WCHAR), &utf8_len);
  if (!utf8)
    goto fail;
 
  redirection_free_data(pData, nullptr);
 
  utf8_len = strnlen(utf8, utf8_len);
  *pData = nullptr;
  if (utf8_len > 0)
    *pData = calloc(utf8_len, sizeof(BYTE));
  if (!*pData)
    goto fail;
 
  {
    size_t rlen = utf8_len;
    size_t wpos = 0;
    char* saveptr = nullptr;
    char* tok = strtok_s(utf8, "\r\n", &saveptr);
    while (tok)
    {
      const size_t len = strnlen(tok, rlen);
      rlen -= len;
 
      size_t bplen = 0;
      BYTE* bptr = nullptr;
      crypto_base64_decode(tok, len, &bptr, &bplen);
      if (!bptr)
        goto fail;
      memcpy(&(*pData)[wpos], bptr, bplen);
      wpos += bplen;
      free(bptr);
 
      tok = strtok_s(nullptr, "\r\n", &saveptr);
    }
    if (wpos > UINT32_MAX)
      goto fail;
 
    *pLength = (UINT32)wpos;
 
    WLog_DBG(TAG, "%s:", rdp_redirection_flags_to_string(flag, buffer, sizeof(buffer)));
  }
 
  rc = TRUE;
fail:
  if (!rc)
    WLog_ERR(TAG, "failed to read base64 data");
  free(utf8);
  return rc;
}
 
static BOOL rdp_target_cert_get_element(wStream* s, UINT32* pType, UINT32* pEncoding,
                                        const BYTE** ptr, size_t* pLength)
{
  WINPR_ASSERT(pType);
  WINPR_ASSERT(pEncoding);
  WINPR_ASSERT(ptr);
  WINPR_ASSERT(pLength);
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 12))
    return FALSE;
 
  UINT32 type = 0;
  UINT32 encoding = 0;
  UINT32 elementSize = 0;
 
  Stream_Read_UINT32(s, type);
  Stream_Read_UINT32(s, encoding);
  Stream_Read_UINT32(s, elementSize);
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, elementSize))
    return FALSE;
 
  *ptr = Stream_ConstPointer(s);
  *pLength = elementSize;
  Stream_Seek(s, elementSize);
 
  *pType = type;
  *pEncoding = encoding;
  return TRUE;
}
 
static BOOL rdp_target_cert_write_element(wStream* s, UINT32 Type, UINT32 Encoding,
                                          const BYTE* data, size_t length)
{
  WINPR_ASSERT(data || (length == 0));
  WINPR_ASSERT(length <= UINT32_MAX);
 
  if (!Stream_EnsureRemainingCapacity(s, 12))
    return FALSE;
 
  Stream_Write_UINT32(s, Type);
  Stream_Write_UINT32(s, Encoding);
  Stream_Write_UINT32(s, (UINT32)length);
 
  if (!Stream_EnsureRemainingCapacity(s, length))
    return FALSE;
 
  Stream_Write(s, data, length);
  return TRUE;
}
 
BOOL rdp_redirection_read_target_cert(rdpCertificate** ptargetCertificate, const BYTE* data,
                                      size_t length)
{
  WINPR_ASSERT(ptargetCertificate);
 
  wStream sbuffer = WINPR_C_ARRAY_INIT;
  wStream* s = Stream_StaticConstInit(&sbuffer, data, length);
 
  freerdp_certificate_free(*ptargetCertificate);
  *ptargetCertificate = nullptr;
 
  size_t plength = 0;
  const BYTE* ptr = nullptr;
  while (Stream_GetRemainingLength(s) > 0)
  {
    UINT32 type = 0;
    UINT32 encoding = 0;
    if (!rdp_target_cert_get_element(s, &type, &encoding, &ptr, &plength))
      return FALSE;
 
    switch (type)
    {
      case CERT_cert_file_element:
        if (encoding == ENCODING_TYPE_ASN1_DER)
        {
          if (*ptargetCertificate)
            WLog_WARN(TAG, "Duplicate TargetCertificate in data detected!");
          else
          {
            *ptargetCertificate = freerdp_certificate_new_from_der(ptr, plength);
            if (!*ptargetCertificate)
              WLog_ERR(TAG, "TargetCertificate parsing DER data failed");
          }
        }
        else
        {
          WLog_ERR(TAG,
                   "TargetCertificate data in unknown encoding %" PRIu32 " detected!",
                   encoding);
        }
        break;
      default: /* ignore unknown fields */
        WLog_VRB(TAG,
                 "Unknown TargetCertificate field type %" PRIu32 ", encoding %" PRIu32
                 " of length %" PRIuz,
                 type, encoding, plength);
        break;
    }
  }
 
  return *ptargetCertificate != nullptr;
}
 
static BOOL rdp_redirection_write_target_cert(wStream* s, const rdpRedirection* redirection)
{
  BOOL rc = FALSE;
  WINPR_ASSERT(redirection);
 
  const rdpCertificate* cert = redirection->TargetCertificate;
  if (!cert)
    return FALSE;
 
  size_t derlen = 0;
 
  BYTE* der = freerdp_certificate_get_der(cert, &derlen);
  if (!rdp_target_cert_write_element(s, CERT_cert_file_element, ENCODING_TYPE_ASN1_DER, der,
                                     derlen))
    goto fail;
 
  rc = TRUE;
 
fail:
  free(der);
  return rc;
}
 
static BOOL rdp_redireciton_write_target_cert_stream(wStream* s, const rdpRedirection* redirection)
{
  BOOL rc = FALSE;
  wStream* serialized = Stream_New(nullptr, 2048);
  if (!serialized)
    goto fail;
 
  if (!rdp_redirection_write_target_cert(serialized, redirection))
    goto fail;
 
  rc = rdp_redirection_write_base64_wchar(
      LB_TARGET_CERTIFICATE, s, Stream_GetPosition(serialized), Stream_Buffer(serialized));
 
fail:
  Stream_Free(serialized, TRUE);
  return rc;
}
 
static BOOL rdp_redirection_read_target_cert_stream(wStream* s, rdpRedirection* redirection)
{
  UINT32 length = 0;
  BYTE* ptr = nullptr;
 
  WINPR_ASSERT(redirection);
 
  BOOL rc = FALSE;
  if (rdp_redirection_read_base64_wchar(LB_TARGET_CERTIFICATE, s, &length, &ptr))
    rc = rdp_redirection_read_target_cert(&redirection->TargetCertificate, ptr, length);
  free(ptr);
  return rc;
}
 
BOOL rdp_set_target_certificate(rdpSettings* settings, const rdpCertificate* tcert)
{
  rdpCertificate* cert = freerdp_certificate_clone(tcert);
  if (!freerdp_settings_set_pointer(settings, FreeRDP_RedirectionTargetCertificate, cert))
    return FALSE;
 
  BOOL pres = FALSE;
  size_t length = 0;
  char* pem = freerdp_certificate_get_pem(cert, &length);
  if (pem && (length <= UINT32_MAX))
  {
    pres =
        freerdp_settings_set_string_len(settings, FreeRDP_RedirectionAcceptedCert, pem, length);
    if (pres)
      pres = freerdp_settings_set_uint32(settings, FreeRDP_RedirectionAcceptedCertLength,
                                         (UINT32)length);
  }
  free(pem);
  return pres;
}
 
int rdp_redirection_apply_settings(rdpRdp* rdp)
{
  rdpSettings* settings = nullptr;
  rdpRedirection* redirection = nullptr;
 
  if (!rdp_reset_runtime_settings(rdp))
    return -1;
 
  settings = rdp->settings;
  WINPR_ASSERT(settings);
 
  redirection = rdp->redirection;
  WINPR_ASSERT(redirection);
 
  settings->RedirectionFlags = redirection->flags;
  settings->RedirectedSessionId = redirection->sessionID;
 
  if (settings->RedirectionFlags & LB_TARGET_NET_ADDRESS)
  {
    if (!freerdp_settings_set_string(settings, FreeRDP_TargetNetAddress,
                                     redirection->TargetNetAddress))
      return -1;
  }
 
  if (settings->RedirectionFlags & LB_USERNAME)
  {
    if (!freerdp_settings_set_string(settings, FreeRDP_RedirectionUsername,
                                     redirection->Username))
      return -1;
  }
 
  if (settings->RedirectionFlags & LB_DOMAIN)
  {
    if (!freerdp_settings_set_string(settings, FreeRDP_RedirectionDomain, redirection->Domain))
      return -1;
  }
 
  if (settings->RedirectionFlags & LB_PASSWORD)
  {
    /* Password may be a cookie without a null terminator */
    if (!freerdp_settings_set_pointer_len(settings, FreeRDP_RedirectionPassword,
                                          redirection->Password, redirection->PasswordLength))
      return -1;
  }
 
  if (settings->RedirectionFlags & LB_DONTSTOREUSERNAME)
  {
    // TODO
  }
 
  if (settings->RedirectionFlags & LB_SMARTCARD_LOGON)
  {
    // TODO
  }
 
  if (settings->RedirectionFlags & LB_NOREDIRECT)
  {
    // TODO
  }
 
  if (settings->RedirectionFlags & LB_TARGET_FQDN)
  {
    if (!freerdp_settings_set_string(settings, FreeRDP_RedirectionTargetFQDN,
                                     redirection->TargetFQDN))
      return -1;
  }
 
  if (settings->RedirectionFlags & LB_TARGET_NETBIOS_NAME)
  {
    if (!freerdp_settings_set_string(settings, FreeRDP_RedirectionTargetNetBiosName,
                                     redirection->TargetNetBiosName))
      return -1;
  }
 
  if (settings->RedirectionFlags & LB_TARGET_NET_ADDRESSES)
  {
    if (!freerdp_target_net_addresses_copy(settings, redirection->TargetNetAddresses,
                                           redirection->TargetNetAddressesCount))
      return -1;
  }
 
  if (settings->RedirectionFlags & LB_CLIENT_TSV_URL)
  {
    /* TsvUrl may not contain a null terminator */
    if (!freerdp_settings_set_pointer_len(settings, FreeRDP_RedirectionTsvUrl,
                                          redirection->TsvUrl, redirection->TsvUrlLength))
      return -1;
 
    const size_t lblen = freerdp_settings_get_uint32(settings, FreeRDP_LoadBalanceInfoLength);
    const char* lb = freerdp_settings_get_pointer(settings, FreeRDP_LoadBalanceInfo);
    if (lblen > 0)
    {
      BOOL valid = TRUE;
      size_t tsvlen = 0;
 
      char* tsv =
          ConvertWCharNToUtf8Alloc(WINPR_PACKED_ALIGN_CAST(const WCHAR*, redirection->TsvUrl),
                                   redirection->TsvUrlLength / sizeof(WCHAR), &tsvlen);
      if (!tsv || !lb)
        valid = FALSE;
      else if (tsvlen != lblen)
        valid = FALSE;
      else if (memcmp(tsv, lb, lblen) != 0)
        valid = FALSE;
 
      if (!valid)
      {
        WLog_ERR(TAG,
                 "[redirection] Expected TsvUrl '%s' [%" PRIuz "], but got '%s' [%" PRIuz
                 "]",
                 lb, lblen, tsv, tsvlen);
      }
      free(tsv);
 
      if (!valid)
        return -2;
    }
  }
 
  if (settings->RedirectionFlags & LB_SERVER_TSV_CAPABLE)
  {
    // TODO
  }
 
  if (settings->RedirectionFlags & LB_LOAD_BALANCE_INFO)
  {
    /* LoadBalanceInfo may not contain a null terminator */
    if (!freerdp_settings_set_pointer_len(settings, FreeRDP_LoadBalanceInfo,
                                          redirection->LoadBalanceInfo,
                                          redirection->LoadBalanceInfoLength))
      return -1;
  }
  else
  {
    if (!freerdp_settings_set_pointer_len(settings, FreeRDP_LoadBalanceInfo, nullptr, 0))
      return -1;
  }
 
  if (settings->RedirectionFlags & LB_PASSWORD_IS_PK_ENCRYPTED)
  {
    // TODO
  }
 
  if (settings->RedirectionFlags & LB_REDIRECTION_GUID)
  {
    if (!freerdp_settings_set_pointer_len(settings, FreeRDP_RedirectionGuid,
                                          redirection->RedirectionGuid,
                                          redirection->RedirectionGuidLength))
      return -1;
  }
 
  if (settings->RedirectionFlags & LB_TARGET_CERTIFICATE)
  {
    if (!rdp_set_target_certificate(settings, redirection->TargetCertificate))
      return -1;
  }
 
  return 0;
}
 
static BOOL rdp_redirection_read_data(UINT32 flag, wStream* s, UINT32* pLength, BYTE** pData)
{
  char buffer[64] = WINPR_C_ARRAY_INIT;
  const BYTE* ptr = nullptr;
 
  const char* msg = rdp_redirection_flags_to_string(flag, buffer, sizeof(buffer));
 
  if (!rdp_redirection_get_data(s, pLength, &ptr))
  {
    WLog_ERR(TAG, "Reading %s failed", msg);
    return FALSE;
  }
 
  redirection_free_data(pData, nullptr);
  *pData = (BYTE*)malloc(*pLength);
 
  if (!*pData)
  {
    WLog_ERR(TAG, "Allocating %" PRIu32 " for %s failed", *pLength, msg);
    return FALSE;
  }
  memcpy(*pData, ptr, *pLength);
 
  WLog_DBG(TAG, "%s:", msg);
 
  return TRUE;
}
 
static state_run_t rdp_recv_server_redirection_pdu(rdpRdp* rdp, wStream* s)
{
  char buffer[256] = WINPR_C_ARRAY_INIT;
  UINT16 flags = 0;
  UINT16 length = 0;
  rdpRedirection* redirection = rdp->redirection;
 
  if (!Stream_CheckAndLogRequiredLength(TAG, s, 12))
    return STATE_RUN_FAILED;
 
  Stream_Read_UINT16(s, flags); /* flags (2 bytes) */
  if (flags != SEC_REDIRECTION_PKT)
  {
    char buffer1[1024] = WINPR_C_ARRAY_INIT;
    char buffer2[1024] = WINPR_C_ARRAY_INIT;
    WLog_ERR(TAG, "received invalid flags=%s, expected %s",
             rdp_security_flag_string(flags, buffer1, sizeof(buffer1)),
             rdp_security_flag_string(SEC_REDIRECTION_PKT, buffer2, sizeof(buffer2)));
    return STATE_RUN_FAILED;
  }
  Stream_Read_UINT16(s, length);                 /* length (2 bytes) */
  Stream_Read_UINT32(s, redirection->sessionID); /* sessionID (4 bytes) */
  Stream_Read_UINT32(s, redirection->flags);     /* redirFlags (4 bytes) */
  WLog_INFO(TAG,
            "flags: 0x%04" PRIX16 ", length: %" PRIu16 ", sessionID: 0x%08" PRIX32
            ", redirFlags: %s [0x%08" PRIX32 "]",
            flags, length, redirection->sessionID,
            rdp_redirection_flags_to_string(redirection->flags, buffer, sizeof(buffer)),
            redirection->flags);
 
  /* Although MS-RDPBCGR does not mention any length constraints limits for the
   * variable length null-terminated unicode strings in the RDP_SERVER_REDIRECTION_PACKET
   * structure we will use the following limits in bytes including the null terminator:
   *
   * TargetNetAddress:     80 bytes
   * UserName:            512 bytes
   * Domain:               52 bytes
   * Password(Cookie):    512 bytes
   * TargetFQDN:          512 bytes
   * TargetNetBiosName:    32 bytes
   */
 
  if (redirection->flags & LB_TARGET_NET_ADDRESS)
  {
    if (!rdp_redirection_read_unicode_string(s, &(redirection->TargetNetAddress), 80) ||
        !utils_is_valid_ip(redirection->TargetNetAddress))
    {
      WLog_ERR(TAG, "TargetNetAddress %s invalid", redirection->TargetNetAddress);
      return STATE_RUN_FAILED;
    }
    WLog_DBG(TAG, "TargetNetAddress %s", redirection->TargetNetAddress);
  }
 
  if (redirection->flags & LB_LOAD_BALANCE_INFO)
  {
    /* See [MSFT-SDLBTS] (a.k.a. TS_Session_Directory.doc)
     * load balance info example data:
     * 0000  43 6f 6f 6b 69 65 3a 20 6d 73 74 73 3d 32 31 33  Cookie: msts=213
     * 0010  34 30 32 36 34 33 32 2e 31 35 36 32 39 2e 30 30  4026432.15629.00
     * 0020  30 30 0d 0a                                      00..
     */
    if (!rdp_redirection_read_data(LB_LOAD_BALANCE_INFO, s, &redirection->LoadBalanceInfoLength,
                                   &redirection->LoadBalanceInfo))
    {
      WLog_ERR(TAG, "LoadBalanceInfo(%" PRIu32 ") invalid",
               redirection->LoadBalanceInfoLength);
      return STATE_RUN_FAILED;
    }
  }
 
  if (redirection->flags & LB_USERNAME)
  {
    if (!rdp_redirection_read_unicode_string(s, &(redirection->Username), 512) ||
        winpr_str_has_newlines(redirection->Username))
    {
      WLog_ERR(TAG, "Username: %s invalid", redirection->Username);
      return STATE_RUN_FAILED;
    }
    WLog_DBG(TAG, "Username: %s", redirection->Username);
  }
 
  if (redirection->flags & LB_DOMAIN)
  {
    if (!rdp_redirection_read_unicode_string(s, &(redirection->Domain), 52) ||
        winpr_str_has_newlines(redirection->Domain))
    {
      WLog_ERR(TAG, "Domain: %s invalid", redirection->Domain);
      return STATE_RUN_FAILED;
    }
    WLog_DBG(TAG, "Domain: %s", redirection->Domain);
  }
 
  if (redirection->flags & LB_PASSWORD)
  {
    /* Note: Password is a variable-length array of bytes containing the
     * password used by the user in Unicode format, including a null-terminator
     * or (!) or a cookie value that MUST be passed to the target server on
     * successful connection.
     * Since the format of the password cookie (probably some salted hash) is
     * currently unknown we'll treat it as opaque data. All cookies seen so far
     * are 120 bytes including \0\0 termination.
     * Here is an observed example of a redirection password cookie:
     *
     * 0000  02 00 00 80 44 53 48 4c 60 ab 69 2f 07 d6 9e 2d  ....DSHL`.i/...-
     * 0010  f0 3a 97 3b a9 c5 ec 7e 66 bd b3 84 6c b1 ef b9  .:.;...~f...l...
     * 0020  b6 82 4e cc 3a df 64 b7 7b 25 04 54 c2 58 98 f8  ..N.:.d.{%.T.X..
     * 0030  97 87 d4 93 c7 c1 e1 5b c2 85 f8 22 49 1f 81 88  .......[..."I...
     * 0040  43 44 83 f6 9a 72 40 24 dc 4d 43 cb d9 92 3c 8f  CD...r@$.MC...<.
     * 0050  3a 37 5c 77 13 a0 72 3c 72 08 64 2a 29 fb dc eb  :7\w..r<r.d*)...
     * 0060  0d 2b 06 b4 c6 08 b4 73 34 16 93 62 6d 24 e9 93  .+.....s4..bm$..
     * 0070  97 27 7b dd 9a 72 00 00                          .'{..r..
     *
     * Notwithstanding the above, we'll allocated an additional zero WCHAR at the
     * end of the buffer which won't get counted in PasswordLength.
     */
    if (!rdp_redirection_read_data(LB_PASSWORD, s, &redirection->PasswordLength,
                                   &redirection->Password))
      return STATE_RUN_FAILED;
 
    /* [MS-RDPBCGR] specifies 512 bytes as the upper limit for the password length
     * including the null terminatior(s). This should also be enough for the unknown
     * password cookie format (see previous comment).
     */
    if ((redirection->flags & LB_PASSWORD_IS_PK_ENCRYPTED) == 0)
    {
      const size_t charLen = redirection->PasswordLength / sizeof(WCHAR);
      if (redirection->PasswordLength > LB_PASSWORD_MAX_LENGTH)
      {
        WLog_ERR(TAG, "LB_PASSWORD: %" PRIuz " exceeds limit of %d", charLen,
                 LB_PASSWORD_MAX_LENGTH);
        return STATE_RUN_FAILED;
      }
 
      /* Ensure the text password is '\0' terminated */
      if (_wcsnlen(WINPR_PACKED_ALIGN_CAST(const WCHAR*, redirection->Password), charLen) ==
          charLen)
      {
        WLog_ERR(TAG, "LB_PASSWORD: missing '\\0' termination");
        return STATE_RUN_FAILED;
      }
    }
  }
 
  if (redirection->flags & LB_TARGET_FQDN)
  {
    if (!rdp_redirection_read_unicode_string(s, &(redirection->TargetFQDN), 512) ||
        !winpr_str_is_valid_hostname(redirection->TargetFQDN))
    {
      WLog_ERR(TAG, "TargetFQDN: %s invalid", redirection->TargetFQDN);
      return STATE_RUN_FAILED;
    }
    WLog_DBG(TAG, "TargetFQDN: %s", redirection->TargetFQDN);
  }
 
  if (redirection->flags & LB_TARGET_NETBIOS_NAME)
  {
    if (!rdp_redirection_read_unicode_string(s, &(redirection->TargetNetBiosName), 32) ||
        !winpr_str_is_valid_hostname(redirection->TargetNetBiosName))
    {
      WLog_ERR(TAG, "TargetNetBiosName: %s invalid", redirection->TargetNetBiosName);
      return STATE_RUN_FAILED;
    }
    WLog_DBG(TAG, "TargetNetBiosName: %s", redirection->TargetNetBiosName);
  }
 
  if (redirection->flags & LB_CLIENT_TSV_URL)
  {
    if (!rdp_redirection_read_data(LB_CLIENT_TSV_URL, s, &redirection->TsvUrlLength,
                                   &redirection->TsvUrl))
    {
      WLog_ERR(TAG, "Client TSV URL invalid");
      return STATE_RUN_FAILED;
    }
  }
 
  if (redirection->flags & LB_REDIRECTION_GUID)
  {
    if (!rdp_redirection_read_data(LB_REDIRECTION_GUID, s, &redirection->RedirectionGuidLength,
                                   &redirection->RedirectionGuid))
    {
      WLog_ERR(TAG, "Redirection GUID invalid");
      return STATE_RUN_FAILED;
    }
  }
 
  if (redirection->flags & LB_TARGET_CERTIFICATE)
  {
    if (!rdp_redirection_read_target_cert_stream(s, redirection))
    {
      WLog_ERR(TAG, "TargetCertificate invalid");
      return STATE_RUN_FAILED;
    }
  }
 
  if (redirection->flags & LB_TARGET_NET_ADDRESSES)
  {
    UINT32 targetNetAddressesLength = 0;
    UINT32 TargetNetAddressesCount = 0;
 
    if (!Stream_CheckAndLogRequiredLength(TAG, s, 8))
      return STATE_RUN_FAILED;
 
    Stream_Read_UINT32(s, targetNetAddressesLength);
    Stream_Read_UINT32(s, TargetNetAddressesCount);
 
    /* sanity check: the whole packet has a length limit of UINT16_MAX
     * each TargetNetAddress is a WCHAR string, so minimum length 2 bytes
     */
    const size_t size = TargetNetAddressesCount * sizeof(WCHAR);
    if ((size > Stream_GetRemainingLength(s)) || (size > targetNetAddressesLength))
    {
      WLog_ERR(TAG,
               "Invalid RDP_SERVER_REDIRECTION_PACKET::TargetNetAddressLength %" PRIuz
               ", sanity limit is %" PRIuz,
               TargetNetAddressesCount * sizeof(WCHAR), Stream_GetRemainingLength(s));
      return STATE_RUN_FAILED;
    }
 
    redirection_free_array(&redirection->TargetNetAddresses,
                           &redirection->TargetNetAddressesCount);
    if (TargetNetAddressesCount > 0)
    {
      redirection->TargetNetAddresses =
          (char**)calloc(TargetNetAddressesCount, sizeof(char*));
 
      if (!redirection->TargetNetAddresses)
      {
        WLog_ERR(TAG, "TargetNetAddresses %" PRIu32 " failed to allocate",
                 TargetNetAddressesCount);
        return STATE_RUN_FAILED;
      }
    }
    redirection->TargetNetAddressesCount = TargetNetAddressesCount;
 
    WLog_DBG(TAG, "TargetNetAddressesCount: %" PRIu32 "", TargetNetAddressesCount);
 
    for (UINT32 i = 0; i < TargetNetAddressesCount; i++)
    {
      if (!rdp_redirection_read_unicode_string(s, &(redirection->TargetNetAddresses[i]),
                                               80) ||
          !utils_is_valid_ip(redirection->TargetNetAddresses[i]))
      {
        WLog_ERR(TAG, "TargetNetAddresses[%" PRIu32 "]: %s invalid", i,
                 redirection->TargetNetAddresses[i]);
        return STATE_RUN_FAILED;
      }
      WLog_DBG(TAG, "TargetNetAddresses[%" PRIu32 "]: %s", i,
               redirection->TargetNetAddresses[i]);
    }
  }
 
  if (Stream_GetRemainingLength(s) >= 8)
  {
    /* some versions of windows don't included this padding before closing the connection */
    Stream_Seek(s, 8); /* pad (8 bytes) */
  }
 
  if (redirection->flags & LB_NOREDIRECT)
    return STATE_RUN_SUCCESS;
 
  return STATE_RUN_REDIRECT;
}
 
state_run_t rdp_recv_enhanced_security_redirection_packet(rdpRdp* rdp, wStream* s)
{
  state_run_t status = STATE_RUN_SUCCESS;
 
  if (!Stream_SafeSeek(s, 2)) /* pad2Octets (2 bytes) */
    return STATE_RUN_FAILED;
 
  status = rdp_recv_server_redirection_pdu(rdp, s);
 
  if (state_run_failed(status))
  {
    WLog_Print(rdp->log, WLOG_ERROR, "redirection packet invalid, aborting");
    return status;
  }
 
  if (Stream_GetRemainingLength(s) >= 1)
  {
    /* this field is optional, and its absence is not an error */
    Stream_Seek(s, 1); /* pad2Octets (1 byte) */
  }
 
  return status;
}
 
rdpRedirection* redirection_new(void)
{
  rdpRedirection* redirection = (rdpRedirection*)calloc(1, sizeof(rdpRedirection));
 
  if (redirection)
  {
  }
 
  return redirection;
}
 
void redirection_free(rdpRedirection* redirection)
{
  if (redirection)
  {
    redirection_free_data(&redirection->TsvUrl, &redirection->TsvUrlLength);
    redirection_free_string(&redirection->Username);
    redirection_free_string(&redirection->Domain);
    redirection_free_string(&redirection->TargetFQDN);
    redirection_free_string(&redirection->TargetNetBiosName);
    redirection_free_string(&redirection->TargetNetAddress);
    redirection_free_data(&redirection->LoadBalanceInfo, &redirection->LoadBalanceInfoLength);
    redirection_free_data(&redirection->Password, &redirection->PasswordLength);
    redirection_free_data(&redirection->RedirectionGuid, &redirection->RedirectionGuidLength);
    freerdp_certificate_free(redirection->TargetCertificate);
    redirection_free_array(&redirection->TargetNetAddresses,
                           &redirection->TargetNetAddressesCount);
 
    free(redirection);
  }
}
 
static SSIZE_T redir_write_string(WINPR_ATTR_UNUSED UINT32 flag, wStream* s, const char* str)
{
  const SSIZE_T devNameWLen = ConvertUtf8ToWChar(str, nullptr, 0);
  if (devNameWLen < 0)
    return -1;
  const size_t length = WINPR_ASSERTING_INT_CAST(size_t, devNameWLen) + 1;
  const size_t slen = strlen(str);
  if (!Stream_EnsureRemainingCapacity(s, 4ull + length * sizeof(WCHAR)))
    return -1;
 
  const size_t pos = Stream_GetPosition(s);
  Stream_Write_UINT32(s, (UINT32)length * sizeof(WCHAR));
  if (Stream_Write_UTF16_String_From_UTF8(s, length, str, slen, TRUE) < 0)
    return -1;
  return (SSIZE_T)(Stream_GetPosition(s) - pos);
}
 
static BOOL redir_write_data(WINPR_ATTR_UNUSED UINT32 flag, wStream* s, UINT32 length,
                             const BYTE* data)
{
  if (!Stream_EnsureRemainingCapacity(s, 4ull + length))
    return FALSE;
 
  Stream_Write_UINT32(s, length);
  Stream_Write(s, data, length);
  return TRUE;
}
 
BOOL rdp_write_enhanced_security_redirection_packet(wStream* s, const rdpRedirection* redirection)
{
  BOOL rc = FALSE;
 
  WINPR_ASSERT(s);
  WINPR_ASSERT(redirection);
 
  if (!Stream_EnsureRemainingCapacity(s, 14))
    goto fail;
 
  Stream_Write_UINT16(s, 0);
 
  {
    const size_t start = Stream_GetPosition(s);
    Stream_Write_UINT16(s, SEC_REDIRECTION_PKT);
    const size_t lengthOffset = Stream_GetPosition(s);
    Stream_Seek_UINT16(s); /* placeholder for length */
 
    if (redirection->sessionID)
      Stream_Write_UINT32(s, redirection->sessionID);
    else
      Stream_Write_UINT32(s, 0);
 
    Stream_Write_UINT32(s, redirection->flags);
 
    if (redirection->flags & LB_TARGET_NET_ADDRESS)
    {
      if (redir_write_string(LB_TARGET_NET_ADDRESS, s, redirection->TargetNetAddress) < 0)
        goto fail;
    }
 
    if (redirection->flags & LB_LOAD_BALANCE_INFO)
    {
      const UINT32 length = 13 + redirection->LoadBalanceInfoLength + 2;
      if (!Stream_EnsureRemainingCapacity(s, length))
        goto fail;
      Stream_Write_UINT32(s, length);
      Stream_Write(s, "Cookie: msts=", 13);
      Stream_Write(s, redirection->LoadBalanceInfo, redirection->LoadBalanceInfoLength);
      Stream_Write_UINT8(s, 0x0d);
      Stream_Write_UINT8(s, 0x0a);
    }
 
    if (redirection->flags & LB_USERNAME)
    {
      if (redir_write_string(LB_USERNAME, s, redirection->Username) < 0)
        goto fail;
    }
 
    if (redirection->flags & LB_DOMAIN)
    {
      if (redir_write_string(LB_DOMAIN, s, redirection->Domain) < 0)
        goto fail;
    }
 
    if (redirection->flags & LB_PASSWORD)
    {
      /* Password is either UNICODE or opaque data */
      if (!redir_write_data(LB_PASSWORD, s, redirection->PasswordLength,
                            redirection->Password))
        goto fail;
    }
 
    if (redirection->flags & LB_TARGET_FQDN)
    {
      if (redir_write_string(LB_TARGET_FQDN, s, redirection->TargetFQDN) < 0)
        goto fail;
    }
 
    if (redirection->flags & LB_TARGET_NETBIOS_NAME)
    {
      if (redir_write_string(LB_TARGET_NETBIOS_NAME, s, redirection->TargetNetBiosName) < 0)
        goto fail;
    }
 
    if (redirection->flags & LB_CLIENT_TSV_URL)
    {
      if (!redir_write_data(LB_CLIENT_TSV_URL, s, redirection->TsvUrlLength,
                            redirection->TsvUrl))
        goto fail;
    }
 
    if (redirection->flags & LB_REDIRECTION_GUID)
    {
      if (!redir_write_data(LB_REDIRECTION_GUID, s, redirection->RedirectionGuidLength,
                            redirection->RedirectionGuid))
        goto fail;
    }
 
    if (redirection->flags & LB_TARGET_CERTIFICATE)
    {
      if (!rdp_redireciton_write_target_cert_stream(s, redirection))
        goto fail;
    }
 
    if (redirection->flags & LB_TARGET_NET_ADDRESSES)
    {
      UINT32 length = sizeof(UINT32);
 
      if (!Stream_EnsureRemainingCapacity(s, 2ull * sizeof(UINT32)))
        goto fail;
 
      const size_t lstart = Stream_GetPosition(s);
      Stream_Seek_UINT32(s); /* length of field */
      Stream_Write_UINT32(s, redirection->TargetNetAddressesCount);
      for (UINT32 i = 0; i < redirection->TargetNetAddressesCount; i++)
      {
        const SSIZE_T rcc = redir_write_string(LB_TARGET_NET_ADDRESSES, s,
                                               redirection->TargetNetAddresses[i]);
        if (rcc < 0)
          goto fail;
        length += (UINT32)rcc;
      }
 
      /* Write length field */
      const size_t lend = Stream_GetPosition(s);
      if (!Stream_SetPosition(s, lstart))
        goto fail;
      Stream_Write_UINT32(s, length);
      if (!Stream_SetPosition(s, lend))
        goto fail;
    }
 
    /* Padding 8 bytes */
    if (!Stream_EnsureRemainingCapacity(s, 8))
      goto fail;
    Stream_Zero(s, 8);
 
    {
      const size_t end = Stream_GetPosition(s);
      if (!Stream_SetPosition(s, lengthOffset))
        goto fail;
      Stream_Write_UINT16(s, (UINT16)(end - start));
      if (!Stream_SetPosition(s, end))
        goto fail;
    }
  }
 
  rc = TRUE;
fail:
  return rc;
}
 
BOOL redirection_settings_are_valid(rdpRedirection* redirection, UINT32* pFlags)
{
  UINT32 flags = 0;
 
  WINPR_ASSERT(redirection);
 
  if (redirection->flags & LB_CLIENT_TSV_URL)
  {
    if (!redirection->TsvUrl || (redirection->TsvUrlLength == 0))
      flags |= LB_CLIENT_TSV_URL;
  }
 
  if (redirection->flags & LB_SERVER_TSV_CAPABLE)
  {
    if ((redirection->flags & LB_CLIENT_TSV_URL) == 0)
      flags |= LB_SERVER_TSV_CAPABLE;
  }
 
  if (redirection->flags & LB_USERNAME)
  {
    if (utils_str_is_empty(redirection->Username))
      flags |= LB_USERNAME;
  }
 
  if (redirection->flags & LB_DOMAIN)
  {
    if (utils_str_is_empty(redirection->Domain))
      flags |= LB_DOMAIN;
  }
 
  if (redirection->flags & LB_PASSWORD)
  {
    if (!redirection->Password || (redirection->PasswordLength == 0))
      flags |= LB_PASSWORD;
  }
 
  if (redirection->flags & LB_TARGET_FQDN)
  {
    if (utils_str_is_empty(redirection->TargetFQDN))
      flags |= LB_TARGET_FQDN;
  }
 
  if (redirection->flags & LB_LOAD_BALANCE_INFO)
  {
    if (!redirection->LoadBalanceInfo || (redirection->LoadBalanceInfoLength == 0))
      flags |= LB_LOAD_BALANCE_INFO;
  }
 
  if (redirection->flags & LB_TARGET_NETBIOS_NAME)
  {
    if (utils_str_is_empty(redirection->TargetNetBiosName))
      flags |= LB_TARGET_NETBIOS_NAME;
  }
 
  if (redirection->flags & LB_TARGET_NET_ADDRESS)
  {
    if (utils_str_is_empty(redirection->TargetNetAddress))
      flags |= LB_TARGET_NET_ADDRESS;
  }
 
  if (redirection->flags & LB_TARGET_NET_ADDRESSES)
  {
    if (!redirection->TargetNetAddresses || (redirection->TargetNetAddressesCount == 0))
      flags |= LB_TARGET_NET_ADDRESSES;
    else
    {
      for (UINT32 x = 0; x < redirection->TargetNetAddressesCount; x++)
      {
        if (!redirection->TargetNetAddresses[x])
          flags |= LB_TARGET_NET_ADDRESSES;
      }
    }
  }
 
  if (redirection->flags & LB_REDIRECTION_GUID)
  {
    if (!redirection->RedirectionGuid || (redirection->RedirectionGuidLength == 0))
      flags |= LB_REDIRECTION_GUID;
  }
 
  if (redirection->flags & LB_TARGET_CERTIFICATE)
  {
    if (!redirection->TargetCertificate)
      flags |= LB_TARGET_CERTIFICATE;
  }
 
  if (pFlags)
    *pFlags = flags;
  return flags == 0;
}
 
BOOL redirection_set_flags(rdpRedirection* redirection, UINT32 flags)
{
  WINPR_ASSERT(redirection);
  redirection->flags = flags;
  return TRUE;
}
 
BOOL redirection_set_session_id(rdpRedirection* redirection, UINT32 session_id)
{
  WINPR_ASSERT(redirection);
  redirection->sessionID = session_id;
  return TRUE;
}
 
static BOOL redirection_unsupported(const char* fkt, UINT32 flag, UINT32 mask)
{
  char buffer[1024] = WINPR_C_ARRAY_INIT;
  char buffer2[1024] = WINPR_C_ARRAY_INIT;
  WLog_WARN(TAG, "[%s] supported flags are {%s}, have {%s}", fkt,
            rdp_redirection_flags_to_string(mask, buffer, sizeof(buffer)),
            rdp_redirection_flags_to_string(flag, buffer2, sizeof(buffer2)));
  return FALSE;
}
 
BOOL redirection_set_byte_option(rdpRedirection* redirection, UINT32 flag, const BYTE* data,
                                 size_t length)
{
  WINPR_ASSERT(redirection);
  switch (flag)
  {
    case LB_CLIENT_TSV_URL:
      return redirection_copy_data(&redirection->TsvUrl, &redirection->TsvUrlLength, data,
                                   length);
    case LB_PASSWORD:
      return redirection_copy_data(&redirection->Password, &redirection->PasswordLength, data,
                                   length);
    case LB_LOAD_BALANCE_INFO:
      return redirection_copy_data(&redirection->LoadBalanceInfo,
                                   &redirection->LoadBalanceInfoLength, data, length);
    case LB_REDIRECTION_GUID:
      return redirection_copy_data(&redirection->RedirectionGuid,
                                   &redirection->RedirectionGuidLength, data, length);
    case LB_TARGET_CERTIFICATE:
      return rdp_redirection_read_target_cert(&redirection->TargetCertificate, data, length);
    default:
      return redirection_unsupported(__func__, flag,
                                     LB_CLIENT_TSV_URL | LB_PASSWORD | LB_LOAD_BALANCE_INFO |
                                         LB_REDIRECTION_GUID | LB_TARGET_CERTIFICATE);
  }
}
 
BOOL redirection_set_string_option(rdpRedirection* redirection, UINT32 flag, const char* str)
{
  WINPR_ASSERT(redirection);
  switch (flag)
  {
    case LB_USERNAME:
      return redirection_copy_string(&redirection->Username, str);
    case LB_DOMAIN:
      return redirection_copy_string(&redirection->Domain, str);
    case LB_TARGET_FQDN:
      return redirection_copy_string(&redirection->TargetFQDN, str);
    case LB_TARGET_NETBIOS_NAME:
      return redirection_copy_string(&redirection->TargetNetBiosName, str);
    case LB_TARGET_NET_ADDRESS:
      return redirection_copy_string(&redirection->TargetNetAddress, str);
    default:
      return redirection_unsupported(__func__, flag,
                                     LB_USERNAME | LB_DOMAIN | LB_TARGET_FQDN |
                                         LB_TARGET_NETBIOS_NAME | LB_TARGET_NET_ADDRESS);
  }
}
 
BOOL redirection_set_array_option(rdpRedirection* redirection, UINT32 flag, const char** str,
                                  size_t count)
{
  WINPR_ASSERT(redirection);
  switch (flag)
  {
    case LB_TARGET_NET_ADDRESSES:
      return redirection_copy_array(&redirection->TargetNetAddresses,
                                    &redirection->TargetNetAddressesCount, str, count);
    default:
      return redirection_unsupported(__func__, flag, LB_TARGET_NET_ADDRESSES);
  }
}