RSA_SaveEncPrivateKey

Saves a private key string to a PKCS-8 EncryptedPrivateKeyInfo file.

VB6/VBA

Debug.Print "Testing RSA_SaveEncPrivateKey ..."
Dim strPriFile As String
Dim strEPKFile As String
Dim strPrivateKey As String
Dim strPK1 As String
Dim nChars As String
Dim nRet As Long

strPriFile = "CarlPrivRSASign.pri"

' Read in Carl's unencrypted PrivateKeyInfo data
nChars = RSA_ReadPrivateKeyInfo("", 0, strPriFile, 0)
If nChars <= 0 Then
    MsgBox "Failed to read Private Key file"
    Exit Sub
End If
' Dimension the string to receive it - IMPORTANT
strPrivateKey = String(nChars, " ")
' Read in as an "internal" key string
nRet = RSA_ReadPrivateKeyInfo(strPrivateKey, nChars, strPriFile, 0)
If nRet <= 0 Then
    MsgBox "Failed to read Private Key file"
    Exit Sub
End If
Debug.Print "Private key length is " & RSA_KeyBits(strPrivateKey) & " bits"

' Now save it in PKCS#8 encrypted form with a password
strEPKFile = "CarlPrivRSASign.epk"
nRet = RSA_SaveEncPrivateKey(strEPKFile, strPrivateKey, 1000, "password", 0)
Debug.Print "RSA_SaveEncPrivateKey returns " & nRet & " (expected 0)"

' Check we can read it (note easier wrapper function)
strPK1 = rsaReadPrivateKey(strEPKFile, "password")
If Len(strPK1) > 0 Then
    Debug.Print "Encrypted private key is " & RSA_KeyBits(strPK1) & " bits"
Else
    MsgBox "Unable to read encrypted private key"
End If

' To compare these strings, use the RSA_KeyHashCode function
Debug.Print "HashCode(original prikeyinfo) =" & Hex(RSA_KeyHashCode(strPrivateKey))
Debug.Print "HashCode(encrypted prikeyinfo)=" & Hex(RSA_KeyHashCode(strPK1))
If RSA_KeyHashCode(strPK1) = RSA_KeyHashCode(strPrivateKey) Then
    Debug.Print "OK, Key string values match."
Else
    Debug.Print "ERROR: key strings do not match."
End If

Output

Testing RSA_SaveEncPrivateKey ...
Private key length is 1024 bits
RSA_SaveEncPrivateKey returns 0 (expected 0)
Encrypted private key is 1024 bits
HashCode(original prikeyinfo) =A937B1B5
HashCode(encrypted prikeyinfo)=A937B1B5
OK, Key string values match.

VB.NET

Console.WriteLine("Testing RSA_SaveEncPrivateKey ...")
Dim strPriFile As String
Dim strEPKFile As String
Dim strPrivateKey As String
Dim strPK1 As String
Dim nRet As Integer

strPriFile = "CarlPrivRSASign.pri"

' Read in Carl's unencrypted PrivateKeyInfo data
strPrivateKey = Rsa.ReadPrivateKeyInfo(strPriFile).ToString()
If strPrivateKey.Length = 0 Then
    Console.WriteLine("Failed to read Private Key file")
    Exit Sub
End If
Console.WriteLine("Private key length is " & Rsa.KeyBits(strPrivateKey) & " bits")

' Now save it in PKCS#8 encrypted form with a password
strEPKFile = "CarlPrivRSASign.epk"
nRet = Rsa.SaveEncPrivateKey(strEPKFile, strPrivateKey, 1000, "password", 0, 0)
Console.WriteLine("Rsa.SaveEncPrivateKey returns " & nRet & " (expected 0)")

' Check we can read it 
strPK1 = Rsa.ReadEncPrivateKey(strEPKFile, "password").ToString()
If strPK1.Length > 0 Then
    Console.WriteLine("Encrypted private key is " & Rsa.KeyBits(strPK1) & " bits")
Else
    Console.WriteLine("Unable to read encrypted private key")
End If

' To compare these strings, use the RSA_KeyHashCode function
Console.WriteLine("HashCode(original prikeyinfo) ={0,8:X}", Rsa.KeyHashCode(strPrivateKey))
Console.WriteLine("HashCode(encrypted prikeyinfo)={0,8:X}", Rsa.KeyHashCode(strPK1))
If Rsa.KeyHashCode(strPK1) = Rsa.KeyHashCode(strPrivateKey) Then
    Console.WriteLine("OK, Key string values match.")
Else
    Console.WriteLine("ERROR: key strings do not match.")
End If

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