CNV_Latin1FromUTF8Bytes

CryptoSys PKI Pro Manual

CNV_Latin1FromUTF8Bytes

Converts UTF-8 encoded array of bytes into a Latin-1 string, if possible.

VBA/VB6 Syntax


Public Declare Function CNV_Latin1FromUTF8Bytes Lib "diCrPKI.dll" (ByVal strOutput As String, ByVal nOutChars As Long, ByRef lpInput As Byte, ByVal nBytes As Long) As Long

nLen = CNV_Latin1FromUTF8Bytes(strOutput, nOutChars, lpInput(0), nBytes)

C/C++ Syntax


long __stdcall CNV_Latin1FromUTF8Bytes(char *szOutput, long nOutChars, const unsigned char *lpInput, long nBytes);

Parameters

szOutput: [out] to receive the output.
nOutChars: [in] specifying the maximum number of characters to be received.
lpInput: [in] array containing UTF-8 encoded data.
nBytes: [in] number of bytes in input array.

Returns (VBA/C)

If successful, the return value is a positive number indicating the number of characters (bytes) in the output string, or number of characters required if nOutChars is set to zero; otherwise it returns a negative error code.

VBA Wrapper Syntax

Public Function cnvLatin1FromUTF8Bytes (lpInput() As Byte) As String

.NET Equivalent

Use System.Text.Encoding.UTF8.GetString(bytes).

C++ (STL) Equivalent

static std::string dipki::Cnv::Latin1FromUTF8Bytes (const bvec_t &bv)

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 input must be valid UTF-8 data. Possible errors are INVALID_DATA_ERROR indicating invalid UTF-8 input and OUT_OF_RANGE_ERROR which indicates that the output would contain a character greater than 8 bits in size.

Example (VBA core function)

See CNV_UTF8BytesFromLatin1.

Example (VBA wrapper function)

Dim strData As String
Dim lpDataUTF8() As Byte
strData = "abcóéÍáñ"
Debug.Print "Latin-1 string='" & strData & "'"
Debug.Print " (" & Len(strData) & " characters)"
lpDataUTF8 = cnvUTF8BytesFromLatin1(strData)
Debug.Print "UTF-8=(0x)" & cnvHexStrFromBytes(lpDataUTF8)
Debug.Print " (" & cnvBytesLen(lpDataUTF8) & " bytes)"
Debug.Print "cnvCheckUTF8Bytes returns " & cnvCheckUTF8Bytes(lpDataUTF8) & " (expected 2)"
' And back to a string
Dim strLatin1 As String
strLatin1 = cnvLatin1FromUTF8Bytes(lpDataUTF8)
Debug.Print "Back to string='" & strLatin1 & "'"

Dim strPrivateKey As String
Dim lpData() As Byte
Dim strData As String

' Read in private key to internal key string
strPrivateKey = rsaReadPrivateKey("BobPrivRSAEncrypt.p8e", "password")
Debug.Assert Len(strPrivateKey) > 0

' 1. Decrypted content is UTF-8 encoded
lpData = cmsReadEnvDataToBytes("cmsalice2bob_utf8.p7m", "", strPrivateKey, 0)
Debug.Assert cnvBytesLen(lpData) > 0
Debug.Print "HEX(PT)=" & cnvHexStrFromBytes(lpData)
' Convert from UTF-8-encoded bytes to VB Unicode string
strData = cnvLatin1FromUTF8Bytes(lpData)
Debug.Print "PT=" & strData

' 2. Decrypted content is plain ANSI string
strData = cmsReadEnvDataToString("cms2bobandcarl.p7m", "", strPrivateKey, 0)
Debug.Print "PT=" & strData

' Clean up
strPrivateKey = wipeString(strPrivateKey)

Dim lpData() As Byte
Dim strData As String

' Read UTF-8 encoded data from signed-data CMS object
lpData = cmsReadSigDataToBytes("basicsignedbyalice_utf8.p7m")
Debug.Assert cnvBytesLen(lpData) > 0
Debug.Print "HEX(CONTENT)=" & cnvHexStrFromBytes(lpData)
' Convert from UTF-8-encoded bytes to VB Unicode string
strData = cnvLatin1FromUTF8Bytes(lpData)
Debug.Print "CONTENT='" & strData & "'"