SafeString.c

Go to the documentation of this file.

 
#include "BaseLibInternals.h"
 
#define RSIZE_MAX  (PcdGet32 (PcdMaximumUnicodeStringLength))
 
#define ASCII_RSIZE_MAX  (PcdGet32 (PcdMaximumAsciiStringLength))
 
#define SAFE_STRING_CONSTRAINT_CHECK(Expression, Status)  \
  do { \
    if (!(Expression)) { \
      DEBUG ((DEBUG_VERBOSE, \
        "%a(%d) %a: SAFE_STRING_CONSTRAINT_CHECK(%a) failed.  Return %r\n", \
        __FILE__, DEBUG_LINE_NUMBER, __func__, DEBUG_EXPRESSION_STRING (Expression), Status)); \
      return Status; \
    } \
  } while (FALSE)
 
BOOLEAN
InternalSafeStringIsOverlap (
  IN VOID   *Base1,
  IN UINTN  Size1,
  IN VOID   *Base2,
  IN UINTN  Size2
  )
{
  if ((((UINTN)Base1 >= (UINTN)Base2) && ((UINTN)Base1 < (UINTN)Base2 + Size2)) ||
      (((UINTN)Base2 >= (UINTN)Base1) && ((UINTN)Base2 < (UINTN)Base1 + Size1)))
  {
    return TRUE;
  }
 
  return FALSE;
}
 
BOOLEAN
InternalSafeStringNoStrOverlap (
  IN CHAR16  *Str1,
  IN UINTN   Size1,
  IN CHAR16  *Str2,
  IN UINTN   Size2
  )
{
  return !InternalSafeStringIsOverlap (Str1, Size1 * sizeof (CHAR16), Str2, Size2 * sizeof (CHAR16));
}
 
BOOLEAN
InternalSafeStringNoAsciiStrOverlap (
  IN CHAR8  *Str1,
  IN UINTN  Size1,
  IN CHAR8  *Str2,
  IN UINTN  Size2
  )
{
  return !InternalSafeStringIsOverlap (Str1, Size1, Str2, Size2);
}
 
UINTN
EFIAPI
StrnLenS (
  IN CONST CHAR16  *String,
  IN UINTN         MaxSize
  )
{
  UINTN  Length;
 
  ASSERT (((UINTN)String & BIT0) == 0);
 
  //
  // If String is a null pointer or MaxSize is 0, then the StrnLenS function returns zero.
  //
  if ((String == NULL) || (MaxSize == 0)) {
    return 0;
  }
 
  //
  // Otherwise, the StrnLenS function returns the number of characters that precede the
  // terminating null character. If there is no null character in the first MaxSize characters of
  // String then StrnLenS returns MaxSize. At most the first MaxSize characters of String shall
  // be accessed by StrnLenS.
  //
  Length = 0;
  while (String[Length] != 0) {
    if (Length >= MaxSize - 1) {
      return MaxSize;
    }
 
    Length++;
  }
 
  return Length;
}
 
UINTN
EFIAPI
StrnSizeS (
  IN CONST CHAR16  *String,
  IN UINTN         MaxSize
  )
{
  //
  // If String is a null pointer, then the StrnSizeS function returns zero.
  //
  if (String == NULL) {
    return 0;
  }
 
  //
  // Otherwise, the StrnSizeS function returns the size of the Null-terminated
  // Unicode string in bytes, including the Null terminator. If there is no
  // Null terminator in the first MaxSize characters of String, then StrnSizeS
  // returns (sizeof (CHAR16) * (MaxSize + 1)) to keep a consistent map with
  // the StrnLenS function.
  //
  return (StrnLenS (String, MaxSize) + 1) * sizeof (*String);
}
 
RETURN_STATUS
EFIAPI
StrCpyS (
  OUT CHAR16        *Destination,
  IN  UINTN         DestMax,
  IN  CONST CHAR16  *Source
  )
{
  UINTN  SourceLen;
 
  ASSERT (((UINTN)Destination & BIT0) == 0);
  ASSERT (((UINTN)Source & BIT0) == 0);
 
  //
  // 1. Neither Destination nor Source shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. DestMax shall not be greater than RSIZE_MAX.
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. DestMax shall be greater than StrnLenS(Source, DestMax).
  //
  SourceLen = StrnLenS (Source, DestMax);
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax > SourceLen), RETURN_BUFFER_TOO_SMALL);
 
  //
  // 5. Copying shall not take place between objects that overlap.
  //
  SAFE_STRING_CONSTRAINT_CHECK (InternalSafeStringNoStrOverlap (Destination, DestMax, (CHAR16 *)Source, SourceLen + 1), RETURN_ACCESS_DENIED);
 
  //
  // The StrCpyS function copies the string pointed to by Source (including the terminating
  // null character) into the array pointed to by Destination.
  //
  while (*Source != 0) {
    *(Destination++) = *(Source++);
  }
 
  *Destination = 0;
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrnCpyS (
  OUT CHAR16        *Destination,
  IN  UINTN         DestMax,
  IN  CONST CHAR16  *Source,
  IN  UINTN         Length
  )
{
  UINTN  SourceLen;
 
  ASSERT (((UINTN)Destination & BIT0) == 0);
  ASSERT (((UINTN)Source & BIT0) == 0);
 
  //
  // 1. Neither Destination nor Source shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. Neither DestMax nor Length shall be greater than RSIZE_MAX
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
    SAFE_STRING_CONSTRAINT_CHECK ((Length <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. If Length is not less than DestMax, then DestMax shall be greater than StrnLenS(Source, DestMax).
  //
  SourceLen = StrnLenS (Source, MIN (DestMax, Length));
  if (Length >= DestMax) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax > SourceLen), RETURN_BUFFER_TOO_SMALL);
  }
 
  //
  // 5. Copying shall not take place between objects that overlap.
  //
  if (SourceLen > Length) {
    SourceLen = Length;
  }
 
  SAFE_STRING_CONSTRAINT_CHECK (InternalSafeStringNoStrOverlap (Destination, DestMax, (CHAR16 *)Source, SourceLen + 1), RETURN_ACCESS_DENIED);
 
  //
  // The StrnCpyS function copies not more than Length successive characters (characters that
  // follow a null character are not copied) from the array pointed to by Source to the array
  // pointed to by Destination. If no null character was copied from Source, then Destination[Length] is set to a null
  // character.
  //
  while ((SourceLen > 0) && (*Source != 0)) {
    *(Destination++) = *(Source++);
    SourceLen--;
  }
 
  *Destination = 0;
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrCatS (
  IN OUT CHAR16        *Destination,
  IN     UINTN         DestMax,
  IN     CONST CHAR16  *Source
  )
{
  UINTN  DestLen;
  UINTN  CopyLen;
  UINTN  SourceLen;
 
  ASSERT (((UINTN)Destination & BIT0) == 0);
  ASSERT (((UINTN)Source & BIT0) == 0);
 
  //
  // Let CopyLen denote the value DestMax - StrnLenS(Destination, DestMax) upon entry to StrCatS.
  //
  DestLen = StrnLenS (Destination, DestMax);
  CopyLen = DestMax - DestLen;
 
  //
  // 1. Neither Destination nor Source shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. DestMax shall not be greater than RSIZE_MAX.
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. CopyLen shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((CopyLen != 0), RETURN_BAD_BUFFER_SIZE);
 
  //
  // 5. CopyLen shall be greater than StrnLenS(Source, CopyLen).
  //
  SourceLen = StrnLenS (Source, CopyLen);
  SAFE_STRING_CONSTRAINT_CHECK ((CopyLen > SourceLen), RETURN_BUFFER_TOO_SMALL);
 
  //
  // 6. Copying shall not take place between objects that overlap.
  //
  SAFE_STRING_CONSTRAINT_CHECK (InternalSafeStringNoStrOverlap (Destination, DestMax, (CHAR16 *)Source, SourceLen + 1), RETURN_ACCESS_DENIED);
 
  //
  // The StrCatS function appends a copy of the string pointed to by Source (including the
  // terminating null character) to the end of the string pointed to by Destination. The initial character
  // from Source overwrites the null character at the end of Destination.
  //
  Destination = Destination + DestLen;
  while (*Source != 0) {
    *(Destination++) = *(Source++);
  }
 
  *Destination = 0;
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrnCatS (
  IN OUT CHAR16        *Destination,
  IN     UINTN         DestMax,
  IN     CONST CHAR16  *Source,
  IN     UINTN         Length
  )
{
  UINTN  DestLen;
  UINTN  CopyLen;
  UINTN  SourceLen;
 
  ASSERT (((UINTN)Destination & BIT0) == 0);
  ASSERT (((UINTN)Source & BIT0) == 0);
 
  //
  // Let CopyLen denote the value DestMax - StrnLenS(Destination, DestMax) upon entry to StrnCatS.
  //
  DestLen = StrnLenS (Destination, DestMax);
  CopyLen = DestMax - DestLen;
 
  //
  // 1. Neither Destination nor Source shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. Neither DestMax nor Length shall be greater than RSIZE_MAX.
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
    SAFE_STRING_CONSTRAINT_CHECK ((Length <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. CopyLen shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((CopyLen != 0), RETURN_BAD_BUFFER_SIZE);
 
  //
  // 5. If Length is not less than CopyLen, then CopyLen shall be greater than StrnLenS(Source, CopyLen).
  //
  SourceLen = StrnLenS (Source, MIN (CopyLen, Length));
  if (Length >= CopyLen) {
    SAFE_STRING_CONSTRAINT_CHECK ((CopyLen > SourceLen), RETURN_BUFFER_TOO_SMALL);
  }
 
  //
  // 6. Copying shall not take place between objects that overlap.
  //
  if (SourceLen > Length) {
    SourceLen = Length;
  }
 
  SAFE_STRING_CONSTRAINT_CHECK (InternalSafeStringNoStrOverlap (Destination, DestMax, (CHAR16 *)Source, SourceLen + 1), RETURN_ACCESS_DENIED);
 
  //
  // The StrnCatS function appends not more than Length successive characters (characters
  // that follow a null character are not copied) from the array pointed to by Source to the end of
  // the string pointed to by Destination. The initial character from Source overwrites the null character at
  // the end of Destination. If no null character was copied from Source, then Destination[DestMax-CopyLen+Length] is set to
  // a null character.
  //
  Destination = Destination + DestLen;
  while ((SourceLen > 0) && (*Source != 0)) {
    *(Destination++) = *(Source++);
    SourceLen--;
  }
 
  *Destination = 0;
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrDecimalToUintnS (
  IN  CONST CHAR16  *String,
  OUT       CHAR16  **EndPointer   OPTIONAL,
  OUT       UINTN   *Data
  )
{
  ASSERT (((UINTN)String & BIT0) == 0);
 
  //
  // 1. Neither String nor Data shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Data != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. The length of String shall not be greater than RSIZE_MAX.
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((StrnLenS (String, RSIZE_MAX + 1) <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR16 *)String;
  }
 
  //
  // Ignore the pad spaces (space or tab)
  //
  while ((*String == L' ') || (*String == L'\t')) {
    String++;
  }
 
  //
  // Ignore leading Zeros after the spaces
  //
  while (*String == L'0') {
    String++;
  }
 
  *Data = 0;
 
  while (InternalIsDecimalDigitCharacter (*String)) {
    //
    // If the number represented by String overflows according to the range
    // defined by UINTN, then MAX_UINTN is stored in *Data and
    // RETURN_UNSUPPORTED is returned.
    //
    if (*Data > ((MAX_UINTN - (*String - L'0')) / 10)) {
      *Data = MAX_UINTN;
      if (EndPointer != NULL) {
        *EndPointer = (CHAR16 *)String;
      }
 
      return RETURN_UNSUPPORTED;
    }
 
    *Data = *Data * 10 + (*String - L'0');
    String++;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR16 *)String;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrDecimalToUint64S (
  IN  CONST CHAR16  *String,
  OUT       CHAR16  **EndPointer   OPTIONAL,
  OUT       UINT64  *Data
  )
{
  ASSERT (((UINTN)String & BIT0) == 0);
 
  //
  // 1. Neither String nor Data shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Data != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. The length of String shall not be greater than RSIZE_MAX.
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((StrnLenS (String, RSIZE_MAX + 1) <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR16 *)String;
  }
 
  //
  // Ignore the pad spaces (space or tab)
  //
  while ((*String == L' ') || (*String == L'\t')) {
    String++;
  }
 
  //
  // Ignore leading Zeros after the spaces
  //
  while (*String == L'0') {
    String++;
  }
 
  *Data = 0;
 
  while (InternalIsDecimalDigitCharacter (*String)) {
    //
    // If the number represented by String overflows according to the range
    // defined by UINT64, then MAX_UINT64 is stored in *Data and
    // RETURN_UNSUPPORTED is returned.
    //
    if (*Data > DivU64x32 (MAX_UINT64 - (*String - L'0'), 10)) {
      *Data = MAX_UINT64;
      if (EndPointer != NULL) {
        *EndPointer = (CHAR16 *)String;
      }
 
      return RETURN_UNSUPPORTED;
    }
 
    *Data = MultU64x32 (*Data, 10) + (*String - L'0');
    String++;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR16 *)String;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrHexToUintnS (
  IN  CONST CHAR16  *String,
  OUT       CHAR16  **EndPointer   OPTIONAL,
  OUT       UINTN   *Data
  )
{
  BOOLEAN  FoundLeadingZero;
 
  FoundLeadingZero = FALSE;
  ASSERT (((UINTN)String & BIT0) == 0);
 
  //
  // 1. Neither String nor Data shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Data != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. The length of String shall not be greater than RSIZE_MAX.
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((StrnLenS (String, RSIZE_MAX + 1) <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR16 *)String;
  }
 
  //
  // Ignore the pad spaces (space or tab)
  //
  while ((*String == L' ') || (*String == L'\t')) {
    String++;
  }
 
  //
  // Ignore leading Zeros after the spaces
  //
 
  FoundLeadingZero = *String == L'0';
  while (*String == L'0') {
    String++;
  }
 
  if (CharToUpper (*String) == L'X') {
    if (!FoundLeadingZero) {
      *Data = 0;
      return RETURN_SUCCESS;
    }
 
    //
    // Skip the 'X'
    //
    String++;
  }
 
  *Data = 0;
 
  while (InternalIsHexaDecimalDigitCharacter (*String)) {
    //
    // If the number represented by String overflows according to the range
    // defined by UINTN, then MAX_UINTN is stored in *Data and
    // RETURN_UNSUPPORTED is returned.
    //
    if (*Data > ((MAX_UINTN - InternalHexCharToUintn (*String)) >> 4)) {
      *Data = MAX_UINTN;
      if (EndPointer != NULL) {
        *EndPointer = (CHAR16 *)String;
      }
 
      return RETURN_UNSUPPORTED;
    }
 
    *Data = (*Data << 4) + InternalHexCharToUintn (*String);
    String++;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR16 *)String;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrHexToUint64S (
  IN  CONST CHAR16  *String,
  OUT       CHAR16  **EndPointer   OPTIONAL,
  OUT       UINT64  *Data
  )
{
  BOOLEAN  FoundLeadingZero;
 
  FoundLeadingZero = FALSE;
  ASSERT (((UINTN)String & BIT0) == 0);
 
  //
  // 1. Neither String nor Data shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Data != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. The length of String shall not be greater than RSIZE_MAX.
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((StrnLenS (String, RSIZE_MAX + 1) <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR16 *)String;
  }
 
  //
  // Ignore the pad spaces (space or tab)
  //
  while ((*String == L' ') || (*String == L'\t')) {
    String++;
  }
 
  //
  // Ignore leading Zeros after the spaces
  //
  FoundLeadingZero = *String == L'0';
  while (*String == L'0') {
    String++;
  }
 
  if (CharToUpper (*String) == L'X') {
    if (!FoundLeadingZero) {
      *Data = 0;
      return RETURN_SUCCESS;
    }
 
    //
    // Skip the 'X'
    //
    String++;
  }
 
  *Data = 0;
 
  while (InternalIsHexaDecimalDigitCharacter (*String)) {
    //
    // If the number represented by String overflows according to the range
    // defined by UINT64, then MAX_UINT64 is stored in *Data and
    // RETURN_UNSUPPORTED is returned.
    //
    if (*Data > RShiftU64 (MAX_UINT64 - InternalHexCharToUintn (*String), 4)) {
      *Data = MAX_UINT64;
      if (EndPointer != NULL) {
        *EndPointer = (CHAR16 *)String;
      }
 
      return RETURN_UNSUPPORTED;
    }
 
    *Data = LShiftU64 (*Data, 4) + InternalHexCharToUintn (*String);
    String++;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR16 *)String;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrToIpv6Address (
  IN  CONST CHAR16  *String,
  OUT CHAR16        **EndPointer  OPTIONAL,
  OUT IPv6_ADDRESS  *Address,
  OUT UINT8         *PrefixLength OPTIONAL
  )
{
  RETURN_STATUS  Status;
  UINTN          AddressIndex;
  UINTN          Uintn;
  IPv6_ADDRESS   LocalAddress;
  UINT8          LocalPrefixLength;
  CONST CHAR16   *Pointer;
  CHAR16         *End;
  UINTN          CompressStart;
  BOOLEAN        ExpectPrefix;
 
  LocalPrefixLength = MAX_UINT8;
  CompressStart     = ARRAY_SIZE (Address->Addr);
  ExpectPrefix      = FALSE;
 
  ASSERT (((UINTN)String & BIT0) == 0);
 
  //
  // 1. None of String or Guid shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Address != NULL), RETURN_INVALID_PARAMETER);
 
  for (Pointer = String, AddressIndex = 0; AddressIndex < ARRAY_SIZE (Address->Addr) + 1;) {
    if (!InternalIsHexaDecimalDigitCharacter (*Pointer)) {
      if (*Pointer != L':') {
        //
        // ":" or "/" should be followed by digit characters.
        //
        return RETURN_UNSUPPORTED;
      }
 
      //
      // Meet second ":" after previous ":" or "/"
      // or meet first ":" in the beginning of String.
      //
      if (ExpectPrefix) {
        //
        // ":" shall not be after "/"
        //
        return RETURN_UNSUPPORTED;
      }
 
      if ((CompressStart != ARRAY_SIZE (Address->Addr)) || (AddressIndex == ARRAY_SIZE (Address->Addr))) {
        //
        // "::" can only appear once.
        // "::" can only appear when address is not full length.
        //
        return RETURN_UNSUPPORTED;
      } else {
        //
        // Remember the start of zero compressing.
        //
        CompressStart = AddressIndex;
        Pointer++;
 
        if (CompressStart == 0) {
          if (*Pointer != L':') {
            //
            // Single ":" shall not be in the beginning of String.
            //
            return RETURN_UNSUPPORTED;
          }
 
          Pointer++;
        }
      }
    }
 
    if (!InternalIsHexaDecimalDigitCharacter (*Pointer)) {
      if (*Pointer == L'/') {
        //
        // Might be optional "/P" after "::".
        //
        if (CompressStart != AddressIndex) {
          return RETURN_UNSUPPORTED;
        }
      } else {
        break;
      }
    } else {
      if (!ExpectPrefix) {
        //
        // Get X.
        //
        Status = StrHexToUintnS (Pointer, &End, &Uintn);
        if (RETURN_ERROR (Status) || (End - Pointer > 4)) {
          //
          // Number of hexadecimal digit characters is no more than 4.
          //
          return RETURN_UNSUPPORTED;
        }
 
        Pointer = End;
        //
        // Uintn won't exceed MAX_UINT16 if number of hexadecimal digit characters is no more than 4.
        //
        ASSERT (AddressIndex + 1 < ARRAY_SIZE (Address->Addr));
        LocalAddress.Addr[AddressIndex]     = (UINT8)((UINT16)Uintn >> 8);
        LocalAddress.Addr[AddressIndex + 1] = (UINT8)Uintn;
        AddressIndex                       += 2;
      } else {
        //
        // Get P, then exit the loop.
        //
        Status = StrDecimalToUintnS (Pointer, &End, &Uintn);
        if (RETURN_ERROR (Status) || (End == Pointer) || (Uintn > 128)) {
          //
          // Prefix length should not exceed 128.
          //
          return RETURN_UNSUPPORTED;
        }
 
        LocalPrefixLength = (UINT8)Uintn;
        Pointer           = End;
        break;
      }
    }
 
    //
    // Skip ':' or "/"
    //
    if (*Pointer == L'/') {
      ExpectPrefix = TRUE;
    } else if (*Pointer == L':') {
      if (AddressIndex == ARRAY_SIZE (Address->Addr)) {
        //
        // Meet additional ":" after all 8 16-bit address
        //
        break;
      }
    } else {
      //
      // Meet other character that is not "/" or ":" after all 8 16-bit address
      //
      break;
    }
 
    Pointer++;
  }
 
  if (((AddressIndex == ARRAY_SIZE (Address->Addr)) && (CompressStart != ARRAY_SIZE (Address->Addr))) ||
      ((AddressIndex != ARRAY_SIZE (Address->Addr)) && (CompressStart == ARRAY_SIZE (Address->Addr)))
      )
  {
    //
    // Full length of address shall not have compressing zeros.
    // Non-full length of address shall have compressing zeros.
    //
    return RETURN_UNSUPPORTED;
  }
 
  CopyMem (&Address->Addr[0], &LocalAddress.Addr[0], CompressStart);
  ZeroMem (&Address->Addr[CompressStart], ARRAY_SIZE (Address->Addr) - AddressIndex);
  if (AddressIndex > CompressStart) {
    CopyMem (
      &Address->Addr[CompressStart + ARRAY_SIZE (Address->Addr) - AddressIndex],
      &LocalAddress.Addr[CompressStart],
      AddressIndex - CompressStart
      );
  }
 
  if (PrefixLength != NULL) {
    *PrefixLength = LocalPrefixLength;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR16 *)Pointer;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrToIpv4Address (
  IN  CONST CHAR16  *String,
  OUT CHAR16        **EndPointer  OPTIONAL,
  OUT IPv4_ADDRESS  *Address,
  OUT UINT8         *PrefixLength OPTIONAL
  )
{
  RETURN_STATUS  Status;
  UINTN          AddressIndex;
  UINTN          Uintn;
  IPv4_ADDRESS   LocalAddress;
  UINT8          LocalPrefixLength;
  CHAR16         *Pointer;
 
  LocalPrefixLength = MAX_UINT8;
 
  ASSERT (((UINTN)String & BIT0) == 0);
 
  //
  // 1. None of String or Guid shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Address != NULL), RETURN_INVALID_PARAMETER);
 
  for (Pointer = (CHAR16 *)String, AddressIndex = 0; AddressIndex < ARRAY_SIZE (Address->Addr) + 1;) {
    if (!InternalIsDecimalDigitCharacter (*Pointer)) {
      //
      // D or P contains invalid characters.
      //
      break;
    }
 
    //
    // Get D or P.
    //
    Status = StrDecimalToUintnS ((CONST CHAR16 *)Pointer, &Pointer, &Uintn);
    if (RETURN_ERROR (Status)) {
      return RETURN_UNSUPPORTED;
    }
 
    if (AddressIndex == ARRAY_SIZE (Address->Addr)) {
      //
      // It's P.
      //
      if (Uintn > 32) {
        return RETURN_UNSUPPORTED;
      }
 
      LocalPrefixLength = (UINT8)Uintn;
    } else {
      //
      // It's D.
      //
      if (Uintn > MAX_UINT8) {
        return RETURN_UNSUPPORTED;
      }
 
      LocalAddress.Addr[AddressIndex] = (UINT8)Uintn;
      AddressIndex++;
    }
 
    //
    // Check the '.' or '/', depending on the AddressIndex.
    //
    if (AddressIndex == ARRAY_SIZE (Address->Addr)) {
      if (*Pointer == L'/') {
        //
        // '/P' is in the String.
        // Skip "/" and get P in next loop.
        //
        Pointer++;
      } else {
        //
        // '/P' is not in the String.
        //
        break;
      }
    } else if (AddressIndex < ARRAY_SIZE (Address->Addr)) {
      if (*Pointer == L'.') {
        //
        // D should be followed by '.'
        //
        Pointer++;
      } else {
        return RETURN_UNSUPPORTED;
      }
    }
  }
 
  if (AddressIndex < ARRAY_SIZE (Address->Addr)) {
    return RETURN_UNSUPPORTED;
  }
 
  CopyMem (Address, &LocalAddress, sizeof (*Address));
  if (PrefixLength != NULL) {
    *PrefixLength = LocalPrefixLength;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = Pointer;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrToGuid (
  IN  CONST CHAR16  *String,
  OUT GUID          *Guid
  )
{
  RETURN_STATUS  Status;
  GUID           LocalGuid;
 
  ASSERT (((UINTN)String & BIT0) == 0);
 
  //
  // 1. None of String or Guid shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Guid != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // Get aabbccdd in big-endian.
  //
  Status = StrHexToBytes (String, 2 * sizeof (LocalGuid.Data1), (UINT8 *)&LocalGuid.Data1, sizeof (LocalGuid.Data1));
  if (RETURN_ERROR (Status) || (String[2 * sizeof (LocalGuid.Data1)] != L'-')) {
    return RETURN_UNSUPPORTED;
  }
 
  //
  // Convert big-endian to little-endian.
  //
  LocalGuid.Data1 = SwapBytes32 (LocalGuid.Data1);
  String         += 2 * sizeof (LocalGuid.Data1) + 1;
 
  //
  // Get eeff in big-endian.
  //
  Status = StrHexToBytes (String, 2 * sizeof (LocalGuid.Data2), (UINT8 *)&LocalGuid.Data2, sizeof (LocalGuid.Data2));
  if (RETURN_ERROR (Status) || (String[2 * sizeof (LocalGuid.Data2)] != L'-')) {
    return RETURN_UNSUPPORTED;
  }
 
  //
  // Convert big-endian to little-endian.
  //
  LocalGuid.Data2 = SwapBytes16 (LocalGuid.Data2);
  String         += 2 * sizeof (LocalGuid.Data2) + 1;
 
  //
  // Get gghh in big-endian.
  //
  Status = StrHexToBytes (String, 2 * sizeof (LocalGuid.Data3), (UINT8 *)&LocalGuid.Data3, sizeof (LocalGuid.Data3));
  if (RETURN_ERROR (Status) || (String[2 * sizeof (LocalGuid.Data3)] != L'-')) {
    return RETURN_UNSUPPORTED;
  }
 
  //
  // Convert big-endian to little-endian.
  //
  LocalGuid.Data3 = SwapBytes16 (LocalGuid.Data3);
  String         += 2 * sizeof (LocalGuid.Data3) + 1;
 
  //
  // Get iijj.
  //
  Status = StrHexToBytes (String, 2 * 2, &LocalGuid.Data4[0], 2);
  if (RETURN_ERROR (Status) || (String[2 * 2] != L'-')) {
    return RETURN_UNSUPPORTED;
  }
 
  String += 2 * 2 + 1;
 
  //
  // Get kkllmmnnoopp.
  //
  Status = StrHexToBytes (String, 2 * 6, &LocalGuid.Data4[2], 6);
  if (RETURN_ERROR (Status)) {
    return RETURN_UNSUPPORTED;
  }
 
  CopyGuid (Guid, &LocalGuid);
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
StrHexToBytes (
  IN  CONST CHAR16  *String,
  IN  UINTN         Length,
  OUT UINT8         *Buffer,
  IN  UINTN         MaxBufferSize
  )
{
  UINTN  Index;
 
  ASSERT (((UINTN)String & BIT0) == 0);
 
  //
  // 1. None of String or Buffer shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Buffer != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. Length shall not be greater than RSIZE_MAX.
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((Length <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. Length shall not be odd.
  //
  SAFE_STRING_CONSTRAINT_CHECK (((Length & BIT0) == 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. MaxBufferSize shall equal to or greater than Length / 2.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((MaxBufferSize >= Length / 2), RETURN_BUFFER_TOO_SMALL);
 
  //
  // 5. String shall not contains invalid hexadecimal digits.
  //
  for (Index = 0; Index < Length; Index++) {
    if (!InternalIsHexaDecimalDigitCharacter (String[Index])) {
      break;
    }
  }
 
  if (Index != Length) {
    return RETURN_UNSUPPORTED;
  }
 
  //
  // Convert the hex string to bytes.
  //
  for (Index = 0; Index < Length; Index++) {
    //
    // For even characters, write the upper nibble for each buffer byte,
    // and for even characters, the lower nibble.
    //
    if ((Index & BIT0) == 0) {
      Buffer[Index / 2] = (UINT8)InternalHexCharToUintn (String[Index]) << 4;
    } else {
      Buffer[Index / 2] |= (UINT8)InternalHexCharToUintn (String[Index]);
    }
  }
 
  return RETURN_SUCCESS;
}
 
UINTN
EFIAPI
AsciiStrnLenS (
  IN CONST CHAR8  *String,
  IN UINTN        MaxSize
  )
{
  UINTN  Length;
 
  //
  // If String is a null pointer or MaxSize is 0, then the AsciiStrnLenS function returns zero.
  //
  if ((String == NULL) || (MaxSize == 0)) {
    return 0;
  }
 
  //
  // Otherwise, the AsciiStrnLenS function returns the number of characters that precede the
  // terminating null character. If there is no null character in the first MaxSize characters of
  // String then AsciiStrnLenS returns MaxSize. At most the first MaxSize characters of String shall
  // be accessed by AsciiStrnLenS.
  //
  Length = 0;
  while (String[Length] != 0) {
    if (Length >= MaxSize - 1) {
      return MaxSize;
    }
 
    Length++;
  }
 
  return Length;
}
 
UINTN
EFIAPI
AsciiStrnSizeS (
  IN CONST CHAR8  *String,
  IN UINTN        MaxSize
  )
{
  //
  // If String is a null pointer, then the AsciiStrnSizeS function returns
  // zero.
  //
  if (String == NULL) {
    return 0;
  }
 
  //
  // Otherwise, the AsciiStrnSizeS function returns the size of the
  // Null-terminated Ascii string in bytes, including the Null terminator. If
  // there is no Null terminator in the first MaxSize characters of String,
  // then AsciiStrnSizeS returns (sizeof (CHAR8) * (MaxSize + 1)) to keep a
  // consistent map with the AsciiStrnLenS function.
  //
  return (AsciiStrnLenS (String, MaxSize) + 1) * sizeof (*String);
}
 
RETURN_STATUS
EFIAPI
AsciiStrCpyS (
  OUT CHAR8        *Destination,
  IN  UINTN        DestMax,
  IN  CONST CHAR8  *Source
  )
{
  UINTN  SourceLen;
 
  //
  // 1. Neither Destination nor Source shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. DestMax shall not be greater than ASCII_RSIZE_MAX.
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. DestMax shall be greater than AsciiStrnLenS(Source, DestMax).
  //
  SourceLen = AsciiStrnLenS (Source, DestMax);
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax > SourceLen), RETURN_BUFFER_TOO_SMALL);
 
  //
  // 5. Copying shall not take place between objects that overlap.
  //
  SAFE_STRING_CONSTRAINT_CHECK (InternalSafeStringNoAsciiStrOverlap (Destination, DestMax, (CHAR8 *)Source, SourceLen + 1), RETURN_ACCESS_DENIED);
 
  //
  // The AsciiStrCpyS function copies the string pointed to by Source (including the terminating
  // null character) into the array pointed to by Destination.
  //
  while (*Source != 0) {
    *(Destination++) = *(Source++);
  }
 
  *Destination = 0;
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrnCpyS (
  OUT CHAR8        *Destination,
  IN  UINTN        DestMax,
  IN  CONST CHAR8  *Source,
  IN  UINTN        Length
  )
{
  UINTN  SourceLen;
 
  //
  // 1. Neither Destination nor Source shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. Neither DestMax nor Length shall be greater than ASCII_RSIZE_MAX
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
    SAFE_STRING_CONSTRAINT_CHECK ((Length <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. If Length is not less than DestMax, then DestMax shall be greater than AsciiStrnLenS(Source, DestMax).
  //
  SourceLen = AsciiStrnLenS (Source, MIN (DestMax, Length));
  if (Length >= DestMax) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax > SourceLen), RETURN_BUFFER_TOO_SMALL);
  }
 
  //
  // 5. Copying shall not take place between objects that overlap.
  //
  if (SourceLen > Length) {
    SourceLen = Length;
  }
 
  SAFE_STRING_CONSTRAINT_CHECK (InternalSafeStringNoAsciiStrOverlap (Destination, DestMax, (CHAR8 *)Source, SourceLen + 1), RETURN_ACCESS_DENIED);
 
  //
  // The AsciiStrnCpyS function copies not more than Length successive characters (characters that
  // follow a null character are not copied) from the array pointed to by Source to the array
  // pointed to by Destination. If no null character was copied from Source, then Destination[Length] is set to a null
  // character.
  //
  while ((SourceLen > 0) && (*Source != 0)) {
    *(Destination++) = *(Source++);
    SourceLen--;
  }
 
  *Destination = 0;
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrCatS (
  IN OUT CHAR8        *Destination,
  IN     UINTN        DestMax,
  IN     CONST CHAR8  *Source
  )
{
  UINTN  DestLen;
  UINTN  CopyLen;
  UINTN  SourceLen;
 
  //
  // Let CopyLen denote the value DestMax - AsciiStrnLenS(Destination, DestMax) upon entry to AsciiStrCatS.
  //
  DestLen = AsciiStrnLenS (Destination, DestMax);
  CopyLen = DestMax - DestLen;
 
  //
  // 1. Neither Destination nor Source shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. DestMax shall not be greater than ASCII_RSIZE_MAX.
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. CopyLen shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((CopyLen != 0), RETURN_BAD_BUFFER_SIZE);
 
  //
  // 5. CopyLen shall be greater than AsciiStrnLenS(Source, CopyLen).
  //
  SourceLen = AsciiStrnLenS (Source, CopyLen);
  SAFE_STRING_CONSTRAINT_CHECK ((CopyLen > SourceLen), RETURN_BUFFER_TOO_SMALL);
 
  //
  // 6. Copying shall not take place between objects that overlap.
  //
  SAFE_STRING_CONSTRAINT_CHECK (InternalSafeStringNoAsciiStrOverlap (Destination, DestMax, (CHAR8 *)Source, SourceLen + 1), RETURN_ACCESS_DENIED);
 
  //
  // The AsciiStrCatS function appends a copy of the string pointed to by Source (including the
  // terminating null character) to the end of the string pointed to by Destination. The initial character
  // from Source overwrites the null character at the end of Destination.
  //
  Destination = Destination + DestLen;
  while (*Source != 0) {
    *(Destination++) = *(Source++);
  }
 
  *Destination = 0;
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrnCatS (
  IN OUT CHAR8        *Destination,
  IN     UINTN        DestMax,
  IN     CONST CHAR8  *Source,
  IN     UINTN        Length
  )
{
  UINTN  DestLen;
  UINTN  CopyLen;
  UINTN  SourceLen;
 
  //
  // Let CopyLen denote the value DestMax - AsciiStrnLenS(Destination, DestMax) upon entry to AsciiStrnCatS.
  //
  DestLen = AsciiStrnLenS (Destination, DestMax);
  CopyLen = DestMax - DestLen;
 
  //
  // 1. Neither Destination nor Source shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. Neither DestMax nor Length shall be greater than ASCII_RSIZE_MAX.
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
    SAFE_STRING_CONSTRAINT_CHECK ((Length <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. CopyLen shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((CopyLen != 0), RETURN_BAD_BUFFER_SIZE);
 
  //
  // 5. If Length is not less than CopyLen, then CopyLen shall be greater than AsciiStrnLenS(Source, CopyLen).
  //
  SourceLen = AsciiStrnLenS (Source, MIN (CopyLen, Length));
  if (Length >= CopyLen) {
    SAFE_STRING_CONSTRAINT_CHECK ((CopyLen > SourceLen), RETURN_BUFFER_TOO_SMALL);
  }
 
  //
  // 6. Copying shall not take place between objects that overlap.
  //
  if (SourceLen > Length) {
    SourceLen = Length;
  }
 
  SAFE_STRING_CONSTRAINT_CHECK (InternalSafeStringNoAsciiStrOverlap (Destination, DestMax, (CHAR8 *)Source, SourceLen + 1), RETURN_ACCESS_DENIED);
 
  //
  // The AsciiStrnCatS function appends not more than Length successive characters (characters
  // that follow a null character are not copied) from the array pointed to by Source to the end of
  // the string pointed to by Destination. The initial character from Source overwrites the null character at
  // the end of Destination. If no null character was copied from Source, then Destination[DestMax-CopyLen+Length] is set to
  // a null character.
  //
  Destination = Destination + DestLen;
  while ((SourceLen > 0) && (*Source != 0)) {
    *(Destination++) = *(Source++);
    SourceLen--;
  }
 
  *Destination = 0;
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrDecimalToUintnS (
  IN  CONST CHAR8  *String,
  OUT       CHAR8  **EndPointer   OPTIONAL,
  OUT       UINTN  *Data
  )
{
  //
  // 1. Neither String nor Data shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Data != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. The length of String shall not be greater than ASCII_RSIZE_MAX.
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((AsciiStrnLenS (String, ASCII_RSIZE_MAX + 1) <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR8 *)String;
  }
 
  //
  // Ignore the pad spaces (space or tab)
  //
  while ((*String == ' ') || (*String == '\t')) {
    String++;
  }
 
  //
  // Ignore leading Zeros after the spaces
  //
  while (*String == '0') {
    String++;
  }
 
  *Data = 0;
 
  while (InternalAsciiIsDecimalDigitCharacter (*String)) {
    //
    // If the number represented by String overflows according to the range
    // defined by UINTN, then MAX_UINTN is stored in *Data and
    // RETURN_UNSUPPORTED is returned.
    //
    if (*Data > ((MAX_UINTN - (*String - '0')) / 10)) {
      *Data = MAX_UINTN;
      if (EndPointer != NULL) {
        *EndPointer = (CHAR8 *)String;
      }
 
      return RETURN_UNSUPPORTED;
    }
 
    *Data = *Data * 10 + (*String - '0');
    String++;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR8 *)String;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrDecimalToUint64S (
  IN  CONST CHAR8   *String,
  OUT       CHAR8   **EndPointer   OPTIONAL,
  OUT       UINT64  *Data
  )
{
  //
  // 1. Neither String nor Data shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Data != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. The length of String shall not be greater than ASCII_RSIZE_MAX.
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((AsciiStrnLenS (String, ASCII_RSIZE_MAX + 1) <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR8 *)String;
  }
 
  //
  // Ignore the pad spaces (space or tab)
  //
  while ((*String == ' ') || (*String == '\t')) {
    String++;
  }
 
  //
  // Ignore leading Zeros after the spaces
  //
  while (*String == '0') {
    String++;
  }
 
  *Data = 0;
 
  while (InternalAsciiIsDecimalDigitCharacter (*String)) {
    //
    // If the number represented by String overflows according to the range
    // defined by UINT64, then MAX_UINT64 is stored in *Data and
    // RETURN_UNSUPPORTED is returned.
    //
    if (*Data > DivU64x32 (MAX_UINT64 - (*String - '0'), 10)) {
      *Data = MAX_UINT64;
      if (EndPointer != NULL) {
        *EndPointer = (CHAR8 *)String;
      }
 
      return RETURN_UNSUPPORTED;
    }
 
    *Data = MultU64x32 (*Data, 10) + (*String - '0');
    String++;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR8 *)String;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrHexToUintnS (
  IN  CONST CHAR8  *String,
  OUT       CHAR8  **EndPointer   OPTIONAL,
  OUT       UINTN  *Data
  )
{
  BOOLEAN  FoundLeadingZero;
 
  FoundLeadingZero = FALSE;
  //
  // 1. Neither String nor Data shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Data != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. The length of String shall not be greater than ASCII_RSIZE_MAX.
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((AsciiStrnLenS (String, ASCII_RSIZE_MAX + 1) <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR8 *)String;
  }
 
  //
  // Ignore the pad spaces (space or tab)
  //
  while ((*String == ' ') || (*String == '\t')) {
    String++;
  }
 
  //
  // Ignore leading Zeros after the spaces
  //
  FoundLeadingZero = *String == '0';
  while (*String == '0') {
    String++;
  }
 
  if (AsciiCharToUpper (*String) == 'X') {
    if (!FoundLeadingZero) {
      *Data = 0;
      return RETURN_SUCCESS;
    }
 
    //
    // Skip the 'X'
    //
    String++;
  }
 
  *Data = 0;
 
  while (InternalAsciiIsHexaDecimalDigitCharacter (*String)) {
    //
    // If the number represented by String overflows according to the range
    // defined by UINTN, then MAX_UINTN is stored in *Data and
    // RETURN_UNSUPPORTED is returned.
    //
    if (*Data > ((MAX_UINTN - InternalAsciiHexCharToUintn (*String)) >> 4)) {
      *Data = MAX_UINTN;
      if (EndPointer != NULL) {
        *EndPointer = (CHAR8 *)String;
      }
 
      return RETURN_UNSUPPORTED;
    }
 
    *Data = (*Data << 4) + InternalAsciiHexCharToUintn (*String);
    String++;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR8 *)String;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrHexToUint64S (
  IN  CONST CHAR8   *String,
  OUT       CHAR8   **EndPointer   OPTIONAL,
  OUT       UINT64  *Data
  )
{
  BOOLEAN  FoundLeadingZero;
 
  FoundLeadingZero = FALSE;
  //
  // 1. Neither String nor Data shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Data != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. The length of String shall not be greater than ASCII_RSIZE_MAX.
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((AsciiStrnLenS (String, ASCII_RSIZE_MAX + 1) <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR8 *)String;
  }
 
  //
  // Ignore the pad spaces (space or tab)
  //
  while ((*String == ' ') || (*String == '\t')) {
    String++;
  }
 
  //
  // Ignore leading Zeros after the spaces
  //
  FoundLeadingZero = *String == '0';
  while (*String == '0') {
    String++;
  }
 
  if (AsciiCharToUpper (*String) == 'X') {
    if (!FoundLeadingZero) {
      *Data = 0;
      return RETURN_SUCCESS;
    }
 
    //
    // Skip the 'X'
    //
    String++;
  }
 
  *Data = 0;
 
  while (InternalAsciiIsHexaDecimalDigitCharacter (*String)) {
    //
    // If the number represented by String overflows according to the range
    // defined by UINT64, then MAX_UINT64 is stored in *Data and
    // RETURN_UNSUPPORTED is returned.
    //
    if (*Data > RShiftU64 (MAX_UINT64 - InternalAsciiHexCharToUintn (*String), 4)) {
      *Data = MAX_UINT64;
      if (EndPointer != NULL) {
        *EndPointer = (CHAR8 *)String;
      }
 
      return RETURN_UNSUPPORTED;
    }
 
    *Data = LShiftU64 (*Data, 4) + InternalAsciiHexCharToUintn (*String);
    String++;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR8 *)String;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
UnicodeStrToAsciiStrS (
  IN      CONST CHAR16  *Source,
  OUT     CHAR8         *Destination,
  IN      UINTN         DestMax
  )
{
  UINTN  SourceLen;
 
  ASSERT (((UINTN)Source & BIT0) == 0);
 
  //
  // 1. Neither Destination nor Source shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. DestMax shall not be greater than ASCII_RSIZE_MAX or RSIZE_MAX.
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. DestMax shall be greater than StrnLenS (Source, DestMax).
  //
  SourceLen = StrnLenS (Source, DestMax);
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax > SourceLen), RETURN_BUFFER_TOO_SMALL);
 
  //
  // 5. Copying shall not take place between objects that overlap.
  //
  SAFE_STRING_CONSTRAINT_CHECK (!InternalSafeStringIsOverlap (Destination, DestMax, (VOID *)Source, (SourceLen + 1) * sizeof (CHAR16)), RETURN_ACCESS_DENIED);
 
  //
  // convert string
  //
  while (*Source != '\0') {
    //
    // If any Unicode characters in Source contain
    // non-zero value in the upper 8 bits, then ASSERT().
    //
    ASSERT (*Source < 0x100);
    *(Destination++) = (CHAR8)*(Source++);
  }
 
  *Destination = '\0';
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
UnicodeStrnToAsciiStrS (
  IN      CONST CHAR16  *Source,
  IN      UINTN         Length,
  OUT     CHAR8         *Destination,
  IN      UINTN         DestMax,
  OUT     UINTN         *DestinationLength
  )
{
  UINTN  SourceLen;
 
  ASSERT (((UINTN)Source & BIT0) == 0);
 
  //
  // 1. None of Destination, Source or DestinationLength shall be a null
  // pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((DestinationLength != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. Neither Length nor DestMax shall be greater than ASCII_RSIZE_MAX or
  // RSIZE_MAX.
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((Length <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((Length <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. If Length is not less than DestMax, then DestMax shall be greater than
  // StrnLenS(Source, DestMax).
  //
  SourceLen = StrnLenS (Source, DestMax);
  if (Length >= DestMax) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax > SourceLen), RETURN_BUFFER_TOO_SMALL);
  }
 
  //
  // 5. Copying shall not take place between objects that overlap.
  //
  if (SourceLen > Length) {
    SourceLen = Length;
  }
 
  SAFE_STRING_CONSTRAINT_CHECK (!InternalSafeStringIsOverlap (Destination, DestMax, (VOID *)Source, (SourceLen + 1) * sizeof (CHAR16)), RETURN_ACCESS_DENIED);
 
  *DestinationLength = 0;
 
  //
  // Convert string
  //
  while ((*Source != 0) && (SourceLen > 0)) {
    //
    // If any Unicode characters in Source contain non-zero value in the upper
    // 8 bits, then ASSERT().
    //
    ASSERT (*Source < 0x100);
    *(Destination++) = (CHAR8)*(Source++);
    SourceLen--;
    (*DestinationLength)++;
  }
 
  *Destination = 0;
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrToUnicodeStrS (
  IN      CONST CHAR8  *Source,
  OUT     CHAR16       *Destination,
  IN      UINTN        DestMax
  )
{
  UINTN  SourceLen;
 
  ASSERT (((UINTN)Destination & BIT0) == 0);
 
  //
  // 1. Neither Destination nor Source shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. DestMax shall not be greater than RSIZE_MAX or ASCII_RSIZE_MAX.
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. DestMax shall be greater than AsciiStrnLenS(Source, DestMax).
  //
  SourceLen = AsciiStrnLenS (Source, DestMax);
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax > SourceLen), RETURN_BUFFER_TOO_SMALL);
 
  //
  // 5. Copying shall not take place between objects that overlap.
  //
  SAFE_STRING_CONSTRAINT_CHECK (!InternalSafeStringIsOverlap (Destination, DestMax * sizeof (CHAR16), (VOID *)Source, SourceLen + 1), RETURN_ACCESS_DENIED);
 
  //
  // Convert string
  //
  while (*Source != '\0') {
    *(Destination++) = (CHAR16)(UINT8)*(Source++);
  }
 
  *Destination = '\0';
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrnToUnicodeStrS (
  IN      CONST CHAR8  *Source,
  IN      UINTN        Length,
  OUT     CHAR16       *Destination,
  IN      UINTN        DestMax,
  OUT     UINTN        *DestinationLength
  )
{
  UINTN  SourceLen;
 
  ASSERT (((UINTN)Destination & BIT0) == 0);
 
  //
  // 1. None of Destination, Source or DestinationLength shall be a null
  // pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((Destination != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Source != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((DestinationLength != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. Neither Length nor DestMax shall be greater than ASCII_RSIZE_MAX or
  // RSIZE_MAX.
  //
  if (RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((Length <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((Length <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. DestMax shall not equal zero.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((DestMax != 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. If Length is not less than DestMax, then DestMax shall be greater than
  // AsciiStrnLenS(Source, DestMax).
  //
  SourceLen = AsciiStrnLenS (Source, DestMax);
  if (Length >= DestMax) {
    SAFE_STRING_CONSTRAINT_CHECK ((DestMax > SourceLen), RETURN_BUFFER_TOO_SMALL);
  }
 
  //
  // 5. Copying shall not take place between objects that overlap.
  //
  if (SourceLen > Length) {
    SourceLen = Length;
  }
 
  SAFE_STRING_CONSTRAINT_CHECK (!InternalSafeStringIsOverlap (Destination, DestMax * sizeof (CHAR16), (VOID *)Source, SourceLen + 1), RETURN_ACCESS_DENIED);
 
  *DestinationLength = 0;
 
  //
  // Convert string
  //
  while ((*Source != 0) && (SourceLen > 0)) {
    *(Destination++) = (CHAR16)(UINT8)*(Source++);
    SourceLen--;
    (*DestinationLength)++;
  }
 
  *Destination = 0;
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrToIpv6Address (
  IN  CONST CHAR8   *String,
  OUT CHAR8         **EndPointer  OPTIONAL,
  OUT IPv6_ADDRESS  *Address,
  OUT UINT8         *PrefixLength OPTIONAL
  )
{
  RETURN_STATUS  Status;
  UINTN          AddressIndex;
  UINTN          Uintn;
  IPv6_ADDRESS   LocalAddress;
  UINT8          LocalPrefixLength;
  CONST CHAR8    *Pointer;
  CHAR8          *End;
  UINTN          CompressStart;
  BOOLEAN        ExpectPrefix;
 
  LocalPrefixLength = MAX_UINT8;
  CompressStart     = ARRAY_SIZE (Address->Addr);
  ExpectPrefix      = FALSE;
 
  //
  // None of String or Address shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Address != NULL), RETURN_INVALID_PARAMETER);
 
  for (Pointer = String, AddressIndex = 0; AddressIndex < ARRAY_SIZE (Address->Addr) + 1;) {
    if (!InternalAsciiIsHexaDecimalDigitCharacter (*Pointer)) {
      if (*Pointer != ':') {
        //
        // ":" or "/" should be followed by digit characters.
        //
        return RETURN_UNSUPPORTED;
      }
 
      //
      // Meet second ":" after previous ":" or "/"
      // or meet first ":" in the beginning of String.
      //
      if (ExpectPrefix) {
        //
        // ":" shall not be after "/"
        //
        return RETURN_UNSUPPORTED;
      }
 
      if ((CompressStart != ARRAY_SIZE (Address->Addr)) || (AddressIndex == ARRAY_SIZE (Address->Addr))) {
        //
        // "::" can only appear once.
        // "::" can only appear when address is not full length.
        //
        return RETURN_UNSUPPORTED;
      } else {
        //
        // Remember the start of zero compressing.
        //
        CompressStart = AddressIndex;
        Pointer++;
 
        if (CompressStart == 0) {
          if (*Pointer != ':') {
            //
            // Single ":" shall not be in the beginning of String.
            //
            return RETURN_UNSUPPORTED;
          }
 
          Pointer++;
        }
      }
    }
 
    if (!InternalAsciiIsHexaDecimalDigitCharacter (*Pointer)) {
      if (*Pointer == '/') {
        //
        // Might be optional "/P" after "::".
        //
        if (CompressStart != AddressIndex) {
          return RETURN_UNSUPPORTED;
        }
      } else {
        break;
      }
    } else {
      if (!ExpectPrefix) {
        //
        // Get X.
        //
        Status = AsciiStrHexToUintnS (Pointer, &End, &Uintn);
        if (RETURN_ERROR (Status) || (End - Pointer > 4)) {
          //
          // Number of hexadecimal digit characters is no more than 4.
          //
          return RETURN_UNSUPPORTED;
        }
 
        Pointer = End;
        //
        // Uintn won't exceed MAX_UINT16 if number of hexadecimal digit characters is no more than 4.
        //
        ASSERT (AddressIndex + 1 < ARRAY_SIZE (Address->Addr));
        LocalAddress.Addr[AddressIndex]     = (UINT8)((UINT16)Uintn >> 8);
        LocalAddress.Addr[AddressIndex + 1] = (UINT8)Uintn;
        AddressIndex                       += 2;
      } else {
        //
        // Get P, then exit the loop.
        //
        Status = AsciiStrDecimalToUintnS (Pointer, &End, &Uintn);
        if (RETURN_ERROR (Status) || (End == Pointer) || (Uintn > 128)) {
          //
          // Prefix length should not exceed 128.
          //
          return RETURN_UNSUPPORTED;
        }
 
        LocalPrefixLength = (UINT8)Uintn;
        Pointer           = End;
        break;
      }
    }
 
    //
    // Skip ':' or "/"
    //
    if (*Pointer == '/') {
      ExpectPrefix = TRUE;
    } else if (*Pointer == ':') {
      if (AddressIndex == ARRAY_SIZE (Address->Addr)) {
        //
        // Meet additional ":" after all 8 16-bit address
        //
        break;
      }
    } else {
      //
      // Meet other character that is not "/" or ":" after all 8 16-bit address
      //
      break;
    }
 
    Pointer++;
  }
 
  if (((AddressIndex == ARRAY_SIZE (Address->Addr)) && (CompressStart != ARRAY_SIZE (Address->Addr))) ||
      ((AddressIndex != ARRAY_SIZE (Address->Addr)) && (CompressStart == ARRAY_SIZE (Address->Addr)))
      )
  {
    //
    // Full length of address shall not have compressing zeros.
    // Non-full length of address shall have compressing zeros.
    //
    return RETURN_UNSUPPORTED;
  }
 
  CopyMem (&Address->Addr[0], &LocalAddress.Addr[0], CompressStart);
  ZeroMem (&Address->Addr[CompressStart], ARRAY_SIZE (Address->Addr) - AddressIndex);
  if (AddressIndex > CompressStart) {
    CopyMem (
      &Address->Addr[CompressStart + ARRAY_SIZE (Address->Addr) - AddressIndex],
      &LocalAddress.Addr[CompressStart],
      AddressIndex - CompressStart
      );
  }
 
  if (PrefixLength != NULL) {
    *PrefixLength = LocalPrefixLength;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = (CHAR8 *)Pointer;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrToIpv4Address (
  IN  CONST CHAR8   *String,
  OUT CHAR8         **EndPointer  OPTIONAL,
  OUT IPv4_ADDRESS  *Address,
  OUT UINT8         *PrefixLength OPTIONAL
  )
{
  RETURN_STATUS  Status;
  UINTN          AddressIndex;
  UINTN          Uintn;
  IPv4_ADDRESS   LocalAddress;
  UINT8          LocalPrefixLength;
  CHAR8          *Pointer;
 
  LocalPrefixLength = MAX_UINT8;
 
  //
  // None of String or Address shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Address != NULL), RETURN_INVALID_PARAMETER);
 
  for (Pointer = (CHAR8 *)String, AddressIndex = 0; AddressIndex < ARRAY_SIZE (Address->Addr) + 1;) {
    if (!InternalAsciiIsDecimalDigitCharacter (*Pointer)) {
      //
      // D or P contains invalid characters.
      //
      break;
    }
 
    //
    // Get D or P.
    //
    Status = AsciiStrDecimalToUintnS ((CONST CHAR8 *)Pointer, &Pointer, &Uintn);
    if (RETURN_ERROR (Status)) {
      return RETURN_UNSUPPORTED;
    }
 
    if (AddressIndex == ARRAY_SIZE (Address->Addr)) {
      //
      // It's P.
      //
      if (Uintn > 32) {
        return RETURN_UNSUPPORTED;
      }
 
      LocalPrefixLength = (UINT8)Uintn;
    } else {
      //
      // It's D.
      //
      if (Uintn > MAX_UINT8) {
        return RETURN_UNSUPPORTED;
      }
 
      LocalAddress.Addr[AddressIndex] = (UINT8)Uintn;
      AddressIndex++;
    }
 
    //
    // Check the '.' or '/', depending on the AddressIndex.
    //
    if (AddressIndex == ARRAY_SIZE (Address->Addr)) {
      if (*Pointer == '/') {
        //
        // '/P' is in the String.
        // Skip "/" and get P in next loop.
        //
        Pointer++;
      } else {
        //
        // '/P' is not in the String.
        //
        break;
      }
    } else if (AddressIndex < ARRAY_SIZE (Address->Addr)) {
      if (*Pointer == '.') {
        //
        // D should be followed by '.'
        //
        Pointer++;
      } else {
        return RETURN_UNSUPPORTED;
      }
    }
  }
 
  if (AddressIndex < ARRAY_SIZE (Address->Addr)) {
    return RETURN_UNSUPPORTED;
  }
 
  CopyMem (Address, &LocalAddress, sizeof (*Address));
  if (PrefixLength != NULL) {
    *PrefixLength = LocalPrefixLength;
  }
 
  if (EndPointer != NULL) {
    *EndPointer = Pointer;
  }
 
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrToGuid (
  IN  CONST CHAR8  *String,
  OUT GUID         *Guid
  )
{
  RETURN_STATUS  Status;
  GUID           LocalGuid;
 
  //
  // None of String or Guid shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Guid != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // Get aabbccdd in big-endian.
  //
  Status = AsciiStrHexToBytes (String, 2 * sizeof (LocalGuid.Data1), (UINT8 *)&LocalGuid.Data1, sizeof (LocalGuid.Data1));
  if (RETURN_ERROR (Status) || (String[2 * sizeof (LocalGuid.Data1)] != '-')) {
    return RETURN_UNSUPPORTED;
  }
 
  //
  // Convert big-endian to little-endian.
  //
  LocalGuid.Data1 = SwapBytes32 (LocalGuid.Data1);
  String         += 2 * sizeof (LocalGuid.Data1) + 1;
 
  //
  // Get eeff in big-endian.
  //
  Status = AsciiStrHexToBytes (String, 2 * sizeof (LocalGuid.Data2), (UINT8 *)&LocalGuid.Data2, sizeof (LocalGuid.Data2));
  if (RETURN_ERROR (Status) || (String[2 * sizeof (LocalGuid.Data2)] != '-')) {
    return RETURN_UNSUPPORTED;
  }
 
  //
  // Convert big-endian to little-endian.
  //
  LocalGuid.Data2 = SwapBytes16 (LocalGuid.Data2);
  String         += 2 * sizeof (LocalGuid.Data2) + 1;
 
  //
  // Get gghh in big-endian.
  //
  Status = AsciiStrHexToBytes (String, 2 * sizeof (LocalGuid.Data3), (UINT8 *)&LocalGuid.Data3, sizeof (LocalGuid.Data3));
  if (RETURN_ERROR (Status) || (String[2 * sizeof (LocalGuid.Data3)] != '-')) {
    return RETURN_UNSUPPORTED;
  }
 
  //
  // Convert big-endian to little-endian.
  //
  LocalGuid.Data3 = SwapBytes16 (LocalGuid.Data3);
  String         += 2 * sizeof (LocalGuid.Data3) + 1;
 
  //
  // Get iijj.
  //
  Status = AsciiStrHexToBytes (String, 2 * 2, &LocalGuid.Data4[0], 2);
  if (RETURN_ERROR (Status) || (String[2 * 2] != '-')) {
    return RETURN_UNSUPPORTED;
  }
 
  String += 2 * 2 + 1;
 
  //
  // Get kkllmmnnoopp.
  //
  Status = AsciiStrHexToBytes (String, 2 * 6, &LocalGuid.Data4[2], 6);
  if (RETURN_ERROR (Status)) {
    return RETURN_UNSUPPORTED;
  }
 
  CopyGuid (Guid, &LocalGuid);
  return RETURN_SUCCESS;
}
 
RETURN_STATUS
EFIAPI
AsciiStrHexToBytes (
  IN  CONST CHAR8  *String,
  IN  UINTN        Length,
  OUT UINT8        *Buffer,
  IN  UINTN        MaxBufferSize
  )
{
  UINTN  Index;
 
  //
  // 1. None of String or Buffer shall be a null pointer.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((String != NULL), RETURN_INVALID_PARAMETER);
  SAFE_STRING_CONSTRAINT_CHECK ((Buffer != NULL), RETURN_INVALID_PARAMETER);
 
  //
  // 2. Length shall not be greater than ASCII_RSIZE_MAX.
  //
  if (ASCII_RSIZE_MAX != 0) {
    SAFE_STRING_CONSTRAINT_CHECK ((Length <= ASCII_RSIZE_MAX), RETURN_INVALID_PARAMETER);
  }
 
  //
  // 3. Length shall not be odd.
  //
  SAFE_STRING_CONSTRAINT_CHECK (((Length & BIT0) == 0), RETURN_INVALID_PARAMETER);
 
  //
  // 4. MaxBufferSize shall equal to or greater than Length / 2.
  //
  SAFE_STRING_CONSTRAINT_CHECK ((MaxBufferSize >= Length / 2), RETURN_BUFFER_TOO_SMALL);
 
  //
  // 5. String shall not contains invalid hexadecimal digits.
  //
  for (Index = 0; Index < Length; Index++) {
    if (!InternalAsciiIsHexaDecimalDigitCharacter (String[Index])) {
      break;
    }
  }
 
  if (Index != Length) {
    return RETURN_UNSUPPORTED;
  }
 
  //
  // Convert the hex string to bytes.
  //
  for (Index = 0; Index < Length; Index++) {
    //
    // For even characters, write the upper nibble for each buffer byte,
    // and for even characters, the lower nibble.
    //
    if ((Index & BIT0) == 0) {
      Buffer[Index / 2] = (UINT8)InternalAsciiHexCharToUintn (String[Index]) << 4;
    } else {
      Buffer[Index / 2] |= (UINT8)InternalAsciiHexCharToUintn (String[Index]);
    }
  }
 
  return RETURN_SUCCESS;
}