HASH_HexFromHex

Creates a message digest hash in hexadecimal format from data in a hexadecimal-encoded string. The hash algorithm to use is passed in the options parameter.

VBA/VB6 Syntax

nRet = HASH_HexFromHex(strOutput, nMaxChars, strMsgHex, nOptions)


C/C++ Syntax

Parameters

szOutput

[out] to receive hash digest in hexadecimal format.

nOutChars

[in] specifying the maximum number of characters to be received.

szMsgHex

[in] containing the message data in hexadecimal-encoded format.

nOptions

[in] Option flags. Select one of:
PKI_HASH_SHA1 (0) to use the SHA-1 algorithm (default)
PKI_HASH_SHA224 to use the SHA-224 algorithm
PKI_HASH_SHA256 to use the SHA-256 algorithm
PKI_HASH_SHA384 to use the SHA-384 algorithm
PKI_HASH_SHA512 to use the SHA-512 algorithm
PKI_HASH_SHA3_224 to use the SHA-3-224 algorithm
PKI_HASH_SHA3_256 to use the SHA-3-256 algorithm
PKI_HASH_SHA3_384 to use the SHA-3-384 algorithm
PKI_HASH_SHA3_512 to use the SHA-3-512 algorithm
PKI_HASH_MD5 to use the MD5 algorithm
PKI_HASH_MD2 to use the MD2 algorithm (legacy applications)
PKI_HASH_RMD160 to use the RIPEMD-160 algorithm
PKI_HASH_BTC160 to use the Bitcoin160 algorithm, RIPEMD160(SHA256(m))
and optionally add
PKI_HASH_DOUBLE to compute a double hash, HASH(HASH(m))

Returns (VBA/C)

If successful, the return value is the number of characters in or required for the output string; otherwise it returns a negative error code.

VBA Wrapper Syntax

.NET Equivalent

Hash.HexFromHex Method

C++ (STL) Equivalent

Python Equivalent

Remarks

For the "raw" VBA/C function, the user must allocate an output string buffer szOutput of the required length. Specify a zero nOutChars or an empty string for szOutput to find the required length. ANSI C users must add one to this value when allocating memory.

The maximum number of output characters is PKI_MAX_HASH_CHARS (C/C++ users add one). The final digest will be truncated to the specified length if less than the expected size. Valid input hex digits are [0-9A-Fa-f]. The output is always in lower-case letters.

Example (VBA core function)

Dim strDigest As String
Dim nRet As Long
Dim strData As String
' Compute SHA-1("abc")
strDigest = String(PKI_SHA1_CHARS, " ")
strData = "616263"
nRet = HASH_HexFromHex(strDigest, Len(strDigest), strData, PKI_HASH_SHA1)
Debug.Print strDigest
' Compute SHA-224("abc")
strDigest = String(PKI_SHA224_CHARS, " ")
strData = "616263"
nRet = HASH_HexFromHex(strDigest, Len(strDigest), strData, PKI_HASH_SHA224)
Debug.Print strDigest

This should produce the following output:

a9993e364706816aba3e25717850c26c9cd0d89d
23097d223405d8228642a477bda255b32aadbce4bda0b3f7e36c9da7

Example (VBA wrapper function)

Dim strDigest As String
Dim lpMessage() As Byte
Dim lpDigest() As Byte

' Hex <-- Hex
strDigest = hashHexFromHex("616263", PKI_HASH_SHA256)   ' "abc" in hex
Debug.Print strDigest
lpMessage = StrConv("abc", vbFromUnicode)   ' "abc" in a byte array
' Hex <-- Bytes
strDigest = hashHexFromBytes(lpMessage, PKI_HASH_SHA256)
Debug.Print strDigest
' Bytes <-- Bytes
lpDigest = hashBytes(lpMessage, PKI_HASH_SHA256)
Debug.Print cnvHexStrFromBytes(lpDigest)
' Hex <-- File
strDigest = hashHexFromFile("abc.txt", PKI_HASH_SHA256) ' "abc" in a text file
Debug.Print strDigest
' Bytes <-- File
lpDigest = hashFile("abc.txt", PKI_HASH_SHA256)
Debug.Print cnvHexStrFromBytes(lpDigest)

Debug.Print "OK=" & "BA7816BF8F01CFEA414140DE5DAE2223B00361A396177A9CB410FF61F20015AD"

See Also

HASH_HexFromBytes HASH_Bytes

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