From fb4dd857c1bfa0c625c75e754e2386f6698e8a43 Mon Sep 17 00:00:00 2001 From: Ruiyu Ni Date: Tue, 21 Feb 2017 17:54:22 +0800 Subject: [PATCH] MdePkg/BaseLib: Add AsciiStrToGuid/HexToBytes/ToIpv[4/6]Address The patch adds 4 APIs to convert ASCII string to GUID, bytes buffer, IP v4 address and IP v6 address. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ruiyu Ni Reviewed-by: Liming Gao Cc: Jiewen Yao Cc: Siyuan Fu --- MdePkg/Include/Library/BaseLib.h | 214 ++++++++++ MdePkg/Library/BaseLib/SafeString.c | 591 ++++++++++++++++++++++++++++ 2 files changed, 805 insertions(+) diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h index 184aa8db1c..791849b804 100644 --- a/MdePkg/Include/Library/BaseLib.h +++ b/MdePkg/Include/Library/BaseLib.h @@ -2418,6 +2418,220 @@ AsciiStrHexToUint64 ( IN CONST CHAR8 *String ); +/** + Convert a Null-terminated ASCII string to IPv6 address and prefix length. + + This function outputs a value of type IPv6_ADDRESS and may output a value + of type UINT8 by interpreting the contents of the ASCII string specified + by String. The format of the input ASCII string String is as follows: + + X:X:X:X:X:X:X:X[/P] + + X contains one to four hexadecimal digit characters in the range [0-9], [a-f] and + [A-F]. X is converted to a value of type UINT16, whose low byte is stored in low + memory address and high byte is stored in high memory address. P contains decimal + digit characters in the range [0-9]. The running zero in the beginning of P will + be ignored. /P is optional. + + When /P is not in the String, the function stops at the first character that is + not a valid hexadecimal digit character after eight X's are converted. + + When /P is in the String, the function stops at the first character that is not + a valid decimal digit character after P is converted. + + "::" can be used to compress one or more groups of X when X contains only 0. + The "::" can only appear once in the String. + + If String is NULL, then ASSERT(). + + If Address is NULL, then ASSERT(). + + If EndPointer is not NULL and Address is translated from String, a pointer + to the character that stopped the scan is stored at the location pointed to + by EndPointer. + + @param String Pointer to a Null-terminated ASCII string. + @param EndPointer Pointer to character that stops scan. + @param Address Pointer to the converted IPv6 address. + @param PrefixLength Pointer to the converted IPv6 address prefix + length. MAX_UINT8 is returned when /P is + not in the String. + + @retval RETURN_SUCCESS Address is translated from String. + @retval RETURN_INVALID_PARAMETER If String is NULL. + If Data is NULL. + @retval RETURN_UNSUPPORTED If X contains more than four hexadecimal + digit characters. + If String contains "::" and number of X + is not less than 8. + If P starts with character that is not a + valid decimal digit character. + If the decimal number converted from P + exceeds 128. + +**/ +RETURN_STATUS +EFIAPI +AsciiStrToIpv6Address ( + IN CONST CHAR8 *String, + OUT CHAR8 **EndPointer, OPTIONAL + OUT IPv6_ADDRESS *Address, + OUT UINT8 *PrefixLength OPTIONAL + ); + +/** + Convert a Null-terminated ASCII string to IPv4 address and prefix length. + + This function outputs a value of type IPv4_ADDRESS and may output a value + of type UINT8 by interpreting the contents of the ASCII string specified + by String. The format of the input ASCII string String is as follows: + + D.D.D.D[/P] + + D and P are decimal digit characters in the range [0-9]. The running zero in + the beginning of D and P will be ignored. /P is optional. + + When /P is not in the String, the function stops at the first character that is + not a valid decimal digit character after four D's are converted. + + When /P is in the String, the function stops at the first character that is not + a valid decimal digit character after P is converted. + + If String is NULL, then ASSERT(). + + If Address is NULL, then ASSERT(). + + If EndPointer is not NULL and Address is translated from String, a pointer + to the character that stopped the scan is stored at the location pointed to + by EndPointer. + + @param String Pointer to a Null-terminated ASCII string. + @param EndPointer Pointer to character that stops scan. + @param Address Pointer to the converted IPv4 address. + @param PrefixLength Pointer to the converted IPv4 address prefix + length. MAX_UINT8 is returned when /P is + not in the String. + + @retval RETURN_SUCCESS Address is translated from String. + @retval RETURN_INVALID_PARAMETER If String is NULL. + If Data is NULL. + @retval RETURN_UNSUPPORTED If String is not in the correct format. + If any decimal number converted from D + exceeds 255. + If the decimal number converted from P + exceeds 32. + +**/ +RETURN_STATUS +EFIAPI +AsciiStrToIpv4Address ( + IN CONST CHAR8 *String, + OUT CHAR8 **EndPointer, OPTIONAL + OUT IPv4_ADDRESS *Address, + OUT UINT8 *PrefixLength OPTIONAL + ); + +/** + Convert a Null-terminated ASCII GUID string to a value of type + EFI_GUID. + + This function outputs a GUID value by interpreting the contents of + the ASCII string specified by String. The format of the input + ASCII string String consists of 36 characters, as follows: + + aabbccdd-eeff-gghh-iijj-kkllmmnnoopp + + The pairs aa - pp are two characters in the range [0-9], [a-f] and + [A-F], with each pair representing a single byte hexadecimal value. + + The mapping between String and the EFI_GUID structure is as follows: + aa Data1[24:31] + bb Data1[16:23] + cc Data1[8:15] + dd Data1[0:7] + ee Data2[8:15] + ff Data2[0:7] + gg Data3[8:15] + hh Data3[0:7] + ii Data4[0:7] + jj Data4[8:15] + kk Data4[16:23] + ll Data4[24:31] + mm Data4[32:39] + nn Data4[40:47] + oo Data4[48:55] + pp Data4[56:63] + + If String is NULL, then ASSERT(). + If Guid is NULL, then ASSERT(). + + @param String Pointer to a Null-terminated ASCII string. + @param Guid Pointer to the converted GUID. + + @retval RETURN_SUCCESS Guid is translated from String. + @retval RETURN_INVALID_PARAMETER If String is NULL. + If Data is NULL. + @retval RETURN_UNSUPPORTED If String is not as the above format. + +**/ +RETURN_STATUS +EFIAPI +AsciiStrToGuid ( + IN CONST CHAR8 *String, + OUT GUID *Guid + ); + +/** + Convert a Null-terminated ASCII hexadecimal string to a byte array. + + This function outputs a byte array by interpreting the contents of + the ASCII string specified by String in hexadecimal format. The format of + the input ASCII string String is: + + [XX]* + + X is a hexadecimal digit character in the range [0-9], [a-f] and [A-F]. + The function decodes every two hexadecimal digit characters as one byte. The + decoding stops after Length of characters and outputs Buffer containing + (Length / 2) bytes. + + If String is NULL, then ASSERT(). + + If Buffer is NULL, then ASSERT(). + + If Length is not multiple of 2, then ASSERT(). + + If PcdMaximumAsciiStringLength is not zero and Length is greater than + PcdMaximumAsciiStringLength, then ASSERT(). + + If MaxBufferSize is less than (Length / 2), then ASSERT(). + + @param String Pointer to a Null-terminated ASCII string. + @param Length The number of ASCII characters to decode. + @param Buffer Pointer to the converted bytes array. + @param MaxBufferSize The maximum size of Buffer. + + @retval RETURN_SUCCESS Buffer is translated from String. + @retval RETURN_INVALID_PARAMETER If String is NULL. + If Data is NULL. + If Length is not multiple of 2. + If PcdMaximumAsciiStringLength is not zero, + and Length is greater than + PcdMaximumAsciiStringLength. + @retval RETURN_UNSUPPORTED If Length of characters from String contain + a character that is not valid hexadecimal + digit characters, or a Null-terminator. + @retval RETURN_BUFFER_TOO_SMALL If MaxBufferSize is less than (Length / 2). +**/ +RETURN_STATUS +EFIAPI +AsciiStrHexToBytes ( + IN CONST CHAR8 *String, + IN UINTN Length, + OUT UINT8 *Buffer, + IN UINTN MaxBufferSize + ); + #ifndef DISABLE_NEW_DEPRECATED_INTERFACES /** diff --git a/MdePkg/Library/BaseLib/SafeString.c b/MdePkg/Library/BaseLib/SafeString.c index cf6f3e9eb9..b7895adfc0 100644 --- a/MdePkg/Library/BaseLib/SafeString.c +++ b/MdePkg/Library/BaseLib/SafeString.c @@ -3050,3 +3050,594 @@ AsciiStrnToUnicodeStrS ( return RETURN_SUCCESS; } + +/** + Convert a Null-terminated ASCII string to IPv6 address and prefix length. + + This function outputs a value of type IPv6_ADDRESS and may output a value + of type UINT8 by interpreting the contents of the ASCII string specified + by String. The format of the input ASCII string String is as follows: + + X:X:X:X:X:X:X:X[/P] + + X contains one to four hexadecimal digit characters in the range [0-9], [a-f] and + [A-F]. X is converted to a value of type UINT16, whose low byte is stored in low + memory address and high byte is stored in high memory address. P contains decimal + digit characters in the range [0-9]. The running zero in the beginning of P will + be ignored. /P is optional. + + When /P is not in the String, the function stops at the first character that is + not a valid hexadecimal digit character after eight X's are converted. + + When /P is in the String, the function stops at the first character that is not + a valid decimal digit character after P is converted. + + "::" can be used to compress one or more groups of X when X contains only 0. + The "::" can only appear once in the String. + + If String is NULL, then ASSERT(). + + If Address is NULL, then ASSERT(). + + If EndPointer is not NULL and Address is translated from String, a pointer + to the character that stopped the scan is stored at the location pointed to + by EndPointer. + + @param String Pointer to a Null-terminated ASCII string. + @param EndPointer Pointer to character that stops scan. + @param Address Pointer to the converted IPv6 address. + @param PrefixLength Pointer to the converted IPv6 address prefix + length. MAX_UINT8 is returned when /P is + not in the String. + + @retval RETURN_SUCCESS Address is translated from String. + @retval RETURN_INVALID_PARAMETER If String is NULL. + If Data is NULL. + @retval RETURN_UNSUPPORTED If X contains more than four hexadecimal + digit characters. + If String contains "::" and number of X + is not less than 8. + If P starts with character that is not a + valid decimal digit character. + If the decimal number converted from P + exceeds 128. + +**/ +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. + // + 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); + 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; +} + +/** + Convert a Null-terminated ASCII string to IPv4 address and prefix length. + + This function outputs a value of type IPv4_ADDRESS and may output a value + of type UINT8 by interpreting the contents of the ASCII string specified + by String. The format of the input ASCII string String is as follows: + + D.D.D.D[/P] + + D and P are decimal digit characters in the range [0-9]. The running zero in + the beginning of D and P will be ignored. /P is optional. + + When /P is not in the String, the function stops at the first character that is + not a valid decimal digit character after four D's are converted. + + When /P is in the String, the function stops at the first character that is not + a valid decimal digit character after P is converted. + + If String is NULL, then ASSERT(). + + If Address is NULL, then ASSERT(). + + If EndPointer is not NULL and Address is translated from String, a pointer + to the character that stopped the scan is stored at the location pointed to + by EndPointer. + + @param String Pointer to a Null-terminated ASCII string. + @param EndPointer Pointer to character that stops scan. + @param Address Pointer to the converted IPv4 address. + @param PrefixLength Pointer to the converted IPv4 address prefix + length. MAX_UINT8 is returned when /P is + not in the String. + + @retval RETURN_SUCCESS Address is translated from String. + @retval RETURN_INVALID_PARAMETER If String is NULL. + If Data is NULL. + @retval RETURN_UNSUPPORTED If String is not in the correct format. + If any decimal number converted from D + exceeds 255. + If the decimal number converted from P + exceeds 32. + +**/ +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; +} + +/** + Convert a Null-terminated ASCII GUID string to a value of type + EFI_GUID. + + This function outputs a GUID value by interpreting the contents of + the ASCII string specified by String. The format of the input + ASCII string String consists of 36 characters, as follows: + + aabbccdd-eeff-gghh-iijj-kkllmmnnoopp + + The pairs aa - pp are two characters in the range [0-9], [a-f] and + [A-F], with each pair representing a single byte hexadecimal value. + + The mapping between String and the EFI_GUID structure is as follows: + aa Data1[24:31] + bb Data1[16:23] + cc Data1[8:15] + dd Data1[0:7] + ee Data2[8:15] + ff Data2[0:7] + gg Data3[8:15] + hh Data3[0:7] + ii Data4[0:7] + jj Data4[8:15] + kk Data4[16:23] + ll Data4[24:31] + mm Data4[32:39] + nn Data4[40:47] + oo Data4[48:55] + pp Data4[56:63] + + If String is NULL, then ASSERT(). + If Guid is NULL, then ASSERT(). + + @param String Pointer to a Null-terminated ASCII string. + @param Guid Pointer to the converted GUID. + + @retval RETURN_SUCCESS Guid is translated from String. + @retval RETURN_INVALID_PARAMETER If String is NULL. + If Data is NULL. + @retval RETURN_UNSUPPORTED If String is not as the above format. + +**/ +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; +} + +/** + Convert a Null-terminated ASCII hexadecimal string to a byte array. + + This function outputs a byte array by interpreting the contents of + the ASCII string specified by String in hexadecimal format. The format of + the input ASCII string String is: + + [XX]* + + X is a hexadecimal digit character in the range [0-9], [a-f] and [A-F]. + The function decodes every two hexadecimal digit characters as one byte. The + decoding stops after Length of characters and outputs Buffer containing + (Length / 2) bytes. + + If String is NULL, then ASSERT(). + + If Buffer is NULL, then ASSERT(). + + If Length is not multiple of 2, then ASSERT(). + + If PcdMaximumAsciiStringLength is not zero and Length is greater than + PcdMaximumAsciiStringLength, then ASSERT(). + + If MaxBufferSize is less than (Length / 2), then ASSERT(). + + @param String Pointer to a Null-terminated ASCII string. + @param Length The number of ASCII characters to decode. + @param Buffer Pointer to the converted bytes array. + @param MaxBufferSize The maximum size of Buffer. + + @retval RETURN_SUCCESS Buffer is translated from String. + @retval RETURN_INVALID_PARAMETER If String is NULL. + If Data is NULL. + If Length is not multiple of 2. + If PcdMaximumAsciiStringLength is not zero, + and Length is greater than + PcdMaximumAsciiStringLength. + @retval RETURN_UNSUPPORTED If Length of characters from String contain + a character that is not valid hexadecimal + digit characters, or a Null-terminator. + @retval RETURN_BUFFER_TOO_SMALL If MaxBufferSize is less than (Length / 2). +**/ +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; +} +