HASH_Bytes

Creates a message digest hash as a byte array from byte data. The hash algorithm to use is passed in the options parameter.

VBA/VB6 Syntax

nRet = HASH_Bytes(lpDigest(0), nDigLen, lpMessage(0), nMsgLen, nOptions) ' Note the "(0)" after the byte array parameters


C/C++ Syntax

Parameters

lpOutput

[out] array to receive the hash digest.

nOutBytes

[in] specifying the length in bytes of the output array.

lpMessage

[in] array containing the message data

nMsgLen

[in] specifying length of the message data in bytes.

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 bytes in the hash digest array; otherwise it returns a negative error code.

VBA Wrapper Syntax

.NET Equivalent

Hash.BytesFromBytes Method
Hash.Double Method

C++ (STL) Equivalent

Python Equivalent

Remarks

Specify a zero nDigLen parameter to find out the required length of the output array. The maximum possible length is PKI_MAX_HASH_BYTES. Hint: SHA-1 requires 20 bytes; MD5 and MD2 require 16 bytes; SHA-512 requires 64. The final digest will be truncated to the specified length if less than the expected size.

Example (VBA core function)

    Dim nRet As Long
    Dim abDigest() As Byte
    Dim abMessage() As Byte
    Dim nMsgLen As Long
    ' Set up message to be hashed
    abMessage = StrConv("abc", vbFromUnicode)
    nMsgLen = UBound(abMessage) + 1
    ' Pre-dimension digest array (NB zero-based so subtract one)
    ReDim abDigest(PKI_MAX_HASH_BYTES - 1)
    ' Create default hash (SHA1)
    nRet = HASH_Bytes(abDigest(0), PKI_MAX_HASH_BYTES, abMessage(0), nMsgLen, 0)
    If nRet > 0 Then ReDim Preserve abDigest(nRet - 1)
    Debug.Print nRet, cnvHexStrFromBytes(abDigest)
    
    ' Repeat for MD5
    ReDim abDigest(PKI_MAX_HASH_BYTES - 1)
    nRet = HASH_Bytes(abDigest(0), PKI_MAX_HASH_BYTES, abMessage(0), nMsgLen, PKI_HASH_MD5)
    If nRet > 0 Then ReDim Preserve abDigest(nRet - 1)
    Debug.Print nRet, cnvHexStrFromBytes(abDigest)

The above example should produce the following output:

 20           A9993E364706816ABA3E25717850C26C9CD0D89D
 16           900150983CD24FB0D6963F7D28E17F72

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"

Dim strDigest As String
Dim lpMessage() As Byte
Dim lpDigest() As Byte
lpDigest = hashBytes(lpMessage, PKI_HASH_SHA256)
Debug.Print cnvHexStrFromBytes(lpDigest)
lpDigest = hashBytes(lpMessage, PKI_HASH_SHA256)
Debug.Print cnvHexStrFromBytes(lpDigest)
strDigest = hashHexFromBytes(lpMessage, PKI_HASH_SHA256)
Debug.Print strDigest
strDigest = hashHexFromBytes(lpMessage, PKI_HASH_SHA512)
Debug.Print strDigest
strDigest = hashHexFromBytes(lpMessage, PKI_HASH_SHA512)
Debug.Print strDigest

See Also

HASH_HexFromBytes

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