winpr/libwinpr/crt/string.c

 
#include <winpr/config.h>
#include <winpr/assert.h>
 
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <ctype.h>
#include <wctype.h>
#include <wchar.h>
 
#include <winpr/crt.h>
#include <winpr/endian.h>
 
#if defined(WITH_URIPARSER)
#include <uriparser/Uri.h>
#endif
 
#if defined(WINPR_HAVE_REGCOMP)
#include <regex.h>
#endif
 
/* String Manipulation (CRT): http://msdn.microsoft.com/en-us/library/f0151s4x.aspx */
 
#include "../log.h"
#define TAG WINPR_TAG("crt")
 
#if defined(WITH_URIPARSER)
BOOL winpr_str_is_valid_urlN(const char* str, size_t len)
{
  if (!str || (len == 0))
    return FALSE;
 
  const char* errorPos = nullptr;
  UriUriA uri = WINPR_C_ARRAY_INIT;
  const int rc = uriParseSingleUriExA(&uri, str, &str[len - 1], &errorPos);
  uriFreeUriMembersA(&uri);
  return rc == URI_SUCCESS;
}
 
BOOL winpr_str_is_valid_url(const char* str)
{
  if (!str)
    return FALSE;
 
  const char* errorPos = nullptr;
  UriUriA uri = WINPR_C_ARRAY_INIT;
  const int rc = uriParseSingleUriA(&uri, str, &errorPos);
  uriFreeUriMembersA(&uri);
  return rc == URI_SUCCESS;
}
 
char* winpr_str_url_decode(const char* str, size_t len)
{
  char* dst = strndup(str, len);
  if (!dst)
    return nullptr;
 
  if (!uriUnescapeInPlaceExA(dst, URI_FALSE, URI_BR_DONT_TOUCH))
  {
    free(dst);
    return nullptr;
  }
 
  return dst;
}
 
char* winpr_str_url_encode(const char* str, size_t len)
{
  char* dst = calloc(len + 1, sizeof(char) * 3);
  if (!dst)
    return nullptr;
 
  if (!uriEscapeA(str, dst, URI_FALSE, URI_FALSE))
  {
    free(dst);
    return nullptr;
  }
  return dst;
}
 
#else
static const char rfc3986[] = {
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x2d, 0x2e, 0x00,
  0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
  0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x00, 0x00, 0x00, 0x00, 0x5f,
  0x00, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
  0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x00, 0x00, 0x00, 0x7e, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
 
static char hex2bin(char what)
{
  if (what >= 'a')
    what -= 'a' - 'A';
  if (what >= 'A')
    what -= ('A' - 10);
  else
    what -= '0';
  return what;
}
 
static char unescape(const char* what, size_t* px)
{
  if ((*what == '%') && (isxdigit(what[1]) && isxdigit(what[2])))
  {
    *px += 2;
    return 16 * hex2bin(what[1]) + hex2bin(what[2]);
  }
 
  return *what;
}
 
char* winpr_str_url_decode(const char* str, size_t len)
{
  char* dst = calloc(len + 1, sizeof(char));
  if (!dst)
    return nullptr;
 
  size_t pos = 0;
  for (size_t x = 0; x < strnlen(str, len); x++)
  {
    const char* cur = &str[x];
    dst[pos++] = unescape(cur, &x);
  }
  return dst;
}
 
WINPR_ATTR_NODISCARD
static char* escape(char* dst, char what)
{
  if (rfc3986[what & 0xff])
  {
    *dst = what;
    return dst + 1;
  }
 
  if (sprintf(dst, "%%%02" PRIX8, (BYTE)(what & 0xff)) < 0)
    return nullptr;
  return dst + 3;
}
 
char* winpr_str_url_encode(const char* str, size_t len)
{
  char* dst = calloc(len + 1, sizeof(char) * 3);
  if (!dst)
    return nullptr;
 
  char* ptr = dst;
  for (size_t x = 0; x < strnlen(str, len); x++)
  {
    const char cur = str[x];
    ptr = escape(ptr, cur);
  }
  return dst;
}
 
BOOL winpr_str_is_valid_urlN(const char* str, size_t len)
{
  if (!str || (len == 0))
    return FALSE;
 
  char* url = strndup(str, len);
  if (!url)
    return FALSE;
 
  const BOOL rc = winpr_str_is_valid_url(url);
  free(url);
  return rc;
}
 
#if defined(_WIN32)
#include <shlwapi.h>
 
BOOL winpr_str_is_valid_url(const char* str)
{
  if (!str)
    return FALSE;
  return PathIsURLA(str);
}
 
#elif defined(WINPR_HAVE_REGCOMP)
BOOL winpr_str_is_valid_url(const char* str)
{
  if (!str)
    return FALSE;
  regex_t regex = WINPR_C_ARRAY_INIT;
  const char pattern[] = "^([a-z]+://)?([a-zA-Z0-9.-]+)(:[0-9]+)?(/[a-zA-Z0-9./?=&%-]*)?$";
 
  int ret = regcomp(&regex, pattern, REG_EXTENDED);
  if (ret)
  {
    printf("Could not compile regex\n");
    return FALSE;
  }
 
  ret = regexec(&regex, str, 0, nullptr, 0);
  regfree(&regex);
  return ret == 0;
}
 
#else
BOOL winpr_str_is_valid_url(WINPR_ATTR_UNUSED const char* str)
{
  WLog_WARN(TAG, "URL validation not supported by your build, not performing check. Build with "
                 "-DWITH_URIPARSER=ON to fix.");
  return TRUE;
}
#endif
#endif
 
BOOL winpr_str_append(const char* what, char* buffer, size_t size, const char* separator)
{
  const size_t used = strnlen(buffer, size);
  const size_t add = strnlen(what, size);
  const size_t sep_len = separator ? strnlen(separator, size) : 0;
  const size_t sep = (used > 0) ? sep_len : 0;
 
  if (used + add + sep >= size)
    return FALSE;
 
  if ((used > 0) && (sep_len > 0))
    strncat(buffer, separator, sep_len);
 
  strncat(buffer, what, add);
  return TRUE;
}
 
WINPR_ATTR_FORMAT_ARG(3, 4)
int winpr_asprintf(char** s, size_t* slen, WINPR_FORMAT_ARG const char* templ, ...)
{
  va_list ap = WINPR_C_ARRAY_INIT;
 
  va_start(ap, templ);
  int rc = winpr_vasprintf(s, slen, templ, ap);
  va_end(ap);
  return rc;
}
 
WINPR_ATTR_FORMAT_ARG(3, 0)
int winpr_vasprintf(char** s, size_t* slen, WINPR_FORMAT_ARG const char* templ, va_list oap)
{
  va_list ap = WINPR_C_ARRAY_INIT;
 
  *s = nullptr;
  *slen = 0;
 
  va_copy(ap, oap);
  const int length = vsnprintf(nullptr, 0, templ, ap);
  va_end(ap);
  if (length < 0)
    return length;
 
  char* str = calloc((size_t)length + 1UL, sizeof(char));
  if (!str)
    return -1;
 
  va_copy(ap, oap);
  const int plen = vsnprintf(str, (size_t)length + 1UL, templ, ap);
  va_end(ap);
 
  if (length != plen)
  {
    free(str);
    return -1;
  }
  *s = str;
  *slen = (size_t)length;
  return length;
}
 
#ifndef _WIN32
 
char* _strdup(const char* strSource)
{
  if (strSource == nullptr)
    return nullptr;
 
  char* strDestination = strdup(strSource);
 
  if (strDestination == nullptr)
    WLog_ERR(TAG, "strdup");
 
  return strDestination;
}
 
WCHAR* _wcsdup(const WCHAR* strSource)
{
  if (!strSource)
    return nullptr;
 
  size_t len = _wcslen(strSource);
  WCHAR* strDestination = calloc(len + 1, sizeof(WCHAR));
 
  if (strDestination != nullptr)
    memcpy(strDestination, strSource, len * sizeof(WCHAR));
 
  if (strDestination == nullptr)
    WLog_ERR(TAG, "wcsdup");
 
  return strDestination;
}
 
WCHAR* _wcsncat(WCHAR* dst, const WCHAR* src, size_t sz)
{
  WINPR_ASSERT(dst);
  WINPR_ASSERT(src || (sz == 0));
 
  const size_t dlen = _wcslen(dst);
  const size_t slen = _wcsnlen(src, sz);
  for (size_t x = 0; x < slen; x++)
    dst[dlen + x] = src[x];
  dst[dlen + slen] = '\0';
  return dst;
}
 
int _stricmp(const char* string1, const char* string2)
{
  return strcasecmp(string1, string2);
}
 
int _strnicmp(const char* string1, const char* string2, size_t count)
{
  return strncasecmp(string1, string2, count);
}
 
/* _wcscmp -> wcscmp */
 
int _wcscmp(const WCHAR* string1, const WCHAR* string2)
{
  WINPR_ASSERT(string1);
  WINPR_ASSERT(string2);
 
  while (TRUE)
  {
    const WCHAR w1 = *string1++;
    const WCHAR w2 = *string2++;
 
    if (w1 != w2)
      return (int)w1 - w2;
    else if ((w1 == '\0') || (w2 == '\0'))
      return (int)w1 - w2;
  }
}
 
int _wcsncmp(const WCHAR* string1, const WCHAR* string2, size_t count)
{
  WINPR_ASSERT(string1);
  WINPR_ASSERT(string2);
 
  for (size_t x = 0; x < count; x++)
  {
    const WCHAR a = string1[x];
    const WCHAR b = string2[x];
 
    if (a != b)
      return (int)a - b;
    else if ((a == '\0') || (b == '\0'))
      return (int)a - b;
  }
  return 0;
}
 
/* _wcslen -> wcslen */
 
size_t _wcslen(const WCHAR* str)
{
  const WCHAR* p = str;
 
  WINPR_ASSERT(p);
 
  while (*p)
    p++;
 
  return (size_t)(p - str);
}
 
/* _wcsnlen -> wcsnlen */
 
size_t _wcsnlen(const WCHAR* str, size_t max)
{
  WINPR_ASSERT(str);
 
  size_t x = 0;
  for (; x < max; x++)
  {
    if (str[x] == 0)
      return x;
  }
 
  return x;
}
 
/* _wcsstr -> wcsstr */
 
WCHAR* _wcsstr(const WCHAR* str, const WCHAR* strSearch)
{
  WINPR_ASSERT(str);
  WINPR_ASSERT(strSearch);
 
  if (strSearch[0] == '\0')
    return WINPR_CAST_CONST_PTR_AWAY(str, WCHAR*);
 
  const size_t searchLen = _wcslen(strSearch);
  while (*str)
  {
    if (_wcsncmp(str, strSearch, searchLen) == 0)
      return WINPR_CAST_CONST_PTR_AWAY(str, WCHAR*);
    str++;
  }
  return nullptr;
}
 
/* _wcschr -> wcschr */
#if defined(WITHOUT_WINPR_3x_DEPRECATED)
static
#endif
    WCHAR* _wcschr(const WCHAR* str, WCHAR c)
{
  union
  {
    const WCHAR* cc;
    WCHAR* c;
  } cnv;
  const WCHAR* p = str;
 
  while (*p && (*p != c))
    p++;
 
  cnv.cc = (*p == c) ? p : nullptr;
  return cnv.c;
}
 
/* _wcsrchr -> wcsrchr */
#if !defined(WITHOUT_WINPR_3x_DEPRECATED)
WCHAR* _wcsrchr(const WCHAR* str, WCHAR c)
{
  union
  {
    const WCHAR* cc;
    WCHAR* c;
  } cnv;
  const WCHAR* p = nullptr;
 
  if (!str)
    return nullptr;
 
  for (; *str != '\0'; str++)
  {
    const WCHAR ch = *str;
    if (ch == c)
      p = str;
  }
 
  cnv.cc = p;
  return cnv.c;
}
#endif
 
char* strtok_s(char* strToken, const char* strDelimit, char** context)
{
  return strtok_r(strToken, strDelimit, context);
}
 
WCHAR* wcstok_s(WCHAR* strToken, const WCHAR* strDelimit, WCHAR** context)
{
  WCHAR* nextToken = nullptr;
  WCHAR value = 0;
 
  if (!strToken)
    strToken = *context;
 
  value = *strToken;
 
  while (*strToken && _wcschr(strDelimit, value))
  {
    strToken++;
    value = *strToken;
  }
 
  if (!*strToken)
    return nullptr;
 
  nextToken = strToken++;
  value = *strToken;
 
  while (*strToken && !(_wcschr(strDelimit, value)))
  {
    strToken++;
    value = *strToken;
  }
 
  if (*strToken)
    *strToken++ = 0;
 
  *context = strToken;
  return nextToken;
}
 
#endif
 
#if !defined(_WIN32) || defined(_UWP)
 
/* Windows API Sets - api-ms-win-core-string-l2-1-0.dll
 * http://msdn.microsoft.com/en-us/library/hh802935/
 */
 
#include "casing.h"
 
LPSTR CharUpperA(LPSTR lpsz)
{
  size_t length = 0;
 
  if (!lpsz)
    return nullptr;
 
  length = strlen(lpsz);
 
  if (length < 1)
    return (LPSTR) nullptr;
 
  if (length == 1)
  {
    char c = *lpsz;
 
    if ((c >= 'a') && (c <= 'z'))
      c = (char)(c - 'a' + 'A');
 
    *lpsz = c;
    return lpsz;
  }
 
  for (size_t i = 0; i < length; i++)
  {
    if ((lpsz[i] >= 'a') && (lpsz[i] <= 'z'))
      lpsz[i] = (char)(lpsz[i] - 'a' + 'A');
  }
 
  return lpsz;
}
 
LPWSTR CharUpperW(LPWSTR lpsz)
{
  size_t length = 0;
 
  if (!lpsz)
    return nullptr;
 
  length = _wcslen(lpsz);
 
  if (length < 1)
    return (LPWSTR) nullptr;
 
  if (length == 1)
  {
    WCHAR c = *lpsz;
 
    if ((c >= L'a') && (c <= L'z'))
      c = c - L'a' + L'A';
 
    *lpsz = c;
    return lpsz;
  }
 
  for (size_t i = 0; i < length; i++)
  {
    if ((lpsz[i] >= L'a') && (lpsz[i] <= L'z'))
      lpsz[i] = lpsz[i] - L'a' + L'A';
  }
 
  return lpsz;
}
 
DWORD CharUpperBuffA(LPSTR lpsz, DWORD cchLength)
{
  if (cchLength < 1)
    return 0;
 
  for (DWORD i = 0; i < cchLength; i++)
  {
    if ((lpsz[i] >= 'a') && (lpsz[i] <= 'z'))
      lpsz[i] = (char)(lpsz[i] - 'a' + 'A');
  }
 
  return cchLength;
}
 
DWORD CharUpperBuffW(LPWSTR lpsz, DWORD cchLength)
{
  for (DWORD i = 0; i < cchLength; i++)
  {
    WCHAR value = winpr_Data_Get_UINT16(&lpsz[i]);
    value = WINPR_TOUPPERW(value);
    winpr_Data_Write_UINT16(&lpsz[i], value);
  }
 
  return cchLength;
}
 
LPSTR CharLowerA(LPSTR lpsz)
{
  size_t length = 0;
 
  if (!lpsz)
    return (LPSTR) nullptr;
 
  length = strlen(lpsz);
 
  if (length < 1)
    return (LPSTR) nullptr;
 
  if (length == 1)
  {
    char c = *lpsz;
 
    if ((c >= 'A') && (c <= 'Z'))
      c = (char)(c - 'A' + 'a');
 
    *lpsz = c;
    return lpsz;
  }
 
  for (size_t i = 0; i < length; i++)
  {
    if ((lpsz[i] >= 'A') && (lpsz[i] <= 'Z'))
      lpsz[i] = (char)(lpsz[i] - 'A' + 'a');
  }
 
  return lpsz;
}
 
LPWSTR CharLowerW(LPWSTR lpsz)
{
  const size_t len = _wcsnlen(lpsz, UINT32_MAX + 1);
  if (len > UINT32_MAX)
    return nullptr;
  CharLowerBuffW(lpsz, (UINT32)len);
  return lpsz;
}
 
DWORD CharLowerBuffA(LPSTR lpsz, DWORD cchLength)
{
  if (cchLength < 1)
    return 0;
 
  for (DWORD i = 0; i < cchLength; i++)
  {
    if ((lpsz[i] >= 'A') && (lpsz[i] <= 'Z'))
      lpsz[i] = (char)(lpsz[i] - 'A' + 'a');
  }
 
  return cchLength;
}
 
DWORD CharLowerBuffW(LPWSTR lpsz, DWORD cchLength)
{
  for (DWORD i = 0; i < cchLength; i++)
  {
    WCHAR value = winpr_Data_Get_UINT16(&lpsz[i]);
    value = WINPR_TOLOWERW(value);
    winpr_Data_Write_UINT16(&lpsz[i], value);
  }
 
  return cchLength;
}
 
BOOL IsCharAlphaA(CHAR ch)
{
  if (((ch >= 'a') && (ch <= 'z')) || ((ch >= 'A') && (ch <= 'Z')))
    return 1;
  else
    return 0;
}
 
BOOL IsCharAlphaW(WCHAR ch)
{
  if (((ch >= L'a') && (ch <= L'z')) || ((ch >= L'A') && (ch <= L'Z')))
    return 1;
  else
    return 0;
}
 
BOOL IsCharAlphaNumericA(CHAR ch)
{
  if (((ch >= 'a') && (ch <= 'z')) || ((ch >= 'A') && (ch <= 'Z')) ||
      ((ch >= '0') && (ch <= '9')))
    return 1;
  else
    return 0;
}
 
BOOL IsCharAlphaNumericW(WCHAR ch)
{
  if (((ch >= L'a') && (ch <= L'z')) || ((ch >= L'A') && (ch <= L'Z')) ||
      ((ch >= L'0') && (ch <= L'9')))
    return 1;
  else
    return 0;
}
 
BOOL IsCharUpperA(CHAR ch)
{
  if ((ch >= 'A') && (ch <= 'Z'))
    return 1;
  else
    return 0;
}
 
BOOL IsCharUpperW(WCHAR ch)
{
  if ((ch >= L'A') && (ch <= L'Z'))
    return 1;
  else
    return 0;
}
 
BOOL IsCharLowerA(CHAR ch)
{
  if ((ch >= 'a') && (ch <= 'z'))
    return 1;
  else
    return 0;
}
 
BOOL IsCharLowerW(WCHAR ch)
{
  if ((ch >= L'a') && (ch <= L'z'))
    return 1;
  else
    return 0;
}
 
#endif
 
size_t ConvertLineEndingToLF(char* str, size_t size)
{
  size_t skip = 0;
 
  WINPR_ASSERT(str || (size == 0));
  for (size_t x = 0; x < size; x++)
  {
    char c = str[x];
    switch (c)
    {
      case '\r':
        str[x - skip] = '\n';
        if ((x + 1 < size) && (str[x + 1] == '\n'))
          skip++;
        break;
      default:
        str[x - skip] = c;
        break;
    }
  }
  return size - skip;
}
 
char* ConvertLineEndingToCRLF(const char* str, size_t* size)
{
  WINPR_ASSERT(size);
  const size_t s = *size;
  WINPR_ASSERT(str || (s == 0));
 
  *size = 0;
  if (s == 0)
    return nullptr;
 
  size_t linebreaks = 0;
  for (size_t x = 0; x < s - 1; x++)
  {
    char c = str[x];
    switch (c)
    {
      case '\r':
      case '\n':
        linebreaks++;
        break;
      default:
        break;
    }
  }
  char* cnv = calloc(s + linebreaks * 2ull + 1ull, sizeof(char));
  if (!cnv)
    return nullptr;
 
  size_t pos = 0;
  for (size_t x = 0; x < s; x++)
  {
    const char c = str[x];
    switch (c)
    {
      case '\r':
        cnv[pos++] = '\r';
        cnv[pos++] = '\n';
        break;
      case '\n':
        /* Do not duplicate existing \r\n sequences */
        if ((x > 0) && (str[x - 1] != '\r'))
        {
          cnv[pos++] = '\r';
          cnv[pos++] = '\n';
        }
        break;
      default:
        cnv[pos++] = c;
        break;
    }
  }
  *size = pos;
  return cnv;
}
 
char* StrSep(char** stringp, const char* delim)
{
  char* start = *stringp;
  char* p = nullptr;
  p = (start != nullptr) ? strpbrk(start, delim) : nullptr;
 
  if (!p)
    *stringp = nullptr;
  else
  {
    *p = '\0';
    *stringp = p + 1;
  }
 
  return start;
}
 
INT64 GetLine(char** lineptr, size_t* size, FILE* stream)
{
#if defined(_WIN32)
  char c;
  char* n;
  size_t step = 32;
  size_t used = 0;
 
  if (!lineptr || !size)
  {
    errno = EINVAL;
    return -1;
  }
 
  do
  {
    if (used + 2 >= *size)
    {
      *size += step;
      n = realloc(*lineptr, *size);
 
      if (!n)
      {
        return -1;
      }
 
      *lineptr = n;
    }
 
    c = fgetc(stream);
 
    if (c != EOF)
      (*lineptr)[used++] = c;
  } while ((c != '\n') && (c != '\r') && (c != EOF));
 
  (*lineptr)[used] = '\0';
  return used;
#elif !defined(ANDROID) && !defined(IOS)
  return getline(lineptr, size, stream);
#else
  return -1;
#endif
}
 
#if !defined(WINPR_HAVE_STRNDUP)
char* strndup(const char* src, size_t n)
{
  char* dst = calloc(n + 1, sizeof(char));
  if (dst)
    strncpy(dst, src, n);
  return dst;
}
#endif
 
const WCHAR* InitializeConstWCharFromUtf8(const char* str, WCHAR* buffer, size_t len)
{
  WINPR_ASSERT(str);
  WINPR_ASSERT(buffer || (len == 0));
  (void)ConvertUtf8ToWChar(str, buffer, len);
  return buffer;
}
 
WCHAR* wcsndup(const WCHAR* s, size_t n)
{
  if (!s)
    return nullptr;
 
  WCHAR* copy = calloc(n + 1, sizeof(WCHAR));
  if (!copy)
    return nullptr;
  memcpy(copy, s, n * sizeof(WCHAR));
  return copy;
}
 
char* winpr_strnstr(const char* haystack, const char* needle, size_t hlen)
{
  WINPR_ASSERT(haystack || (hlen == 0));
  WINPR_ASSERT(needle);
 
#if defined(WINPR_HAVE_STRNSTR)
  return strnstr(haystack, needle, hlen);
#else
  /* Match native strnstr semantics: search at most hlen characters and stop at
   * the haystack NUL terminator, whichever comes first. */
  const size_t needle_len = strlen(needle);
 
  if (0 == needle_len)
    return WINPR_CAST_CONST_PTR_AWAY(haystack, char*);
 
  for (; (*haystack != '\0') && (hlen >= needle_len); haystack++, hlen--)
  {
    if ((haystack[0] == needle[0]) && (0 == strncmp(haystack, needle, needle_len)))
      return WINPR_CAST_CONST_PTR_AWAY(haystack, char*);
  }
  return nullptr;
#endif
}
 
BOOL winpr_str_has_newlines(const char* str)
{
  if (!str)
    return FALSE;
  do
  {
    char c = *str++;
    switch (c)
    {
      case '\r':
      case '\n':
      case 0x0b:       /* VT vertical tab */
      case 0x0c:       /* FF form feed */
      case (char)0x85: /* NEL next line */
        return TRUE;
      case (char)0xE2:
      {
        if ((str[0] == (char)0x80) && ((str[1] == (char)0xA8) || (str[1] == (char)0xA9)))
          return TRUE;
      }
      break;
 
      case '\0':
        return FALSE;
      default:
        break;
    }
  } while (1);
}
 
WCHAR* winpr_wcsnchr(const WCHAR* str, size_t charLen, WCHAR c)
{
  if (!str || (charLen == 0))
    return nullptr;
 
  const WCHAR* p = str;
  const WCHAR* end = &str[charLen];
 
  while (p != end)
  {
    const WCHAR wc = winpr_Data_Get_UINT16(p);
    if (wc == c)
    {
      union
      {
        WCHAR* w;
        const WCHAR* cw;
      } cnv;
      cnv.cw = p;
      return cnv.w;
    }
    p++;
  }
  return nullptr;
}
 
WCHAR* winpr_wcsnrchr(const WCHAR* str, size_t charLen, WCHAR c)
{
  if (!str || (charLen == 0))
    return nullptr;
 
  const WCHAR* p = str;
  const WCHAR* end = &str[charLen];
 
  union
  {
    WCHAR* w;
    const WCHAR* cw;
  } cnv;
 
  cnv.cw = nullptr;
  while (p != end)
  {
    const WCHAR wc = winpr_Data_Get_UINT16(p);
    if (wc == c)
      cnv.cw = p;
    p++;
  }
  return cnv.w;
}