PowerBuilder

Manually Duplicate SetSecretKeyViaPassword

Demonstrates how to duplicate the password string to binary secret key computation of SetSecretKeyViaPassword.

This is a cryptographically weak way of generating a secret key from a password. The SetSecretKeyViaPassword method is deprecated and should not be used.

PowerBuilder

integer li_rc
oleobject loo_Crypt
string ls_Password
oleobject loo_Sb
string ls_PasswordBase64

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

loo_Crypt = create oleobject
li_rc = loo_Crypt.ConnectToNewObject("Chilkat.Crypt2")
if li_rc < 0 then
    destroy loo_Crypt
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// The password string is transformed to a binary secret key by computing the 
// MD5 digest (of the utf-8 password) to obtain 16 bytes.  
// If the KeyLength is greater than 16 bytes, then the MD5 digest of the Base64 encoding 
// of the utf-8 password is added.  A max of 32 bytes of key material is generated, and 
// this is truncated to the actual KeyLength required.

loo_Crypt.CryptAlgorithm = "aes"
loo_Crypt.KeyLength = 256

ls_Password = "this is my password"
loo_Crypt.SetSecretKeyViaPassword(ls_Password)

// Examine the resulting SecretKey in hex:
Write-Debug "Computed Secret Key = " + loo_Crypt.GetEncodedKey("hex")

// Now perform the same computation manually:
loo_Sb = create oleobject
li_rc = loo_Sb.ConnectToNewObject("Chilkat.StringBuilder")

loo_Crypt.HashAlgorithm = "md5"
loo_Crypt.Charset = "utf-8"
loo_Crypt.EncodingMode = "hex"
loo_Sb.Append(loo_Crypt.HashStringENC(ls_Password))

ls_PasswordBase64 = loo_Crypt.EncodeString(ls_Password,"utf-8","base64")
loo_Sb.Append(loo_Crypt.HashStringENC(ls_PasswordBase64))

Write-Debug "Manually Computed = " + loo_Sb.GetAsString()

// The output is:
// Computed Secret Key = 210D53992DFF432EC1B1A9698AF9DA16C7E90518F90E24828F78EC9E0A413B36
// Manually Computed = 210D53992DFF432EC1B1A9698AF9DA16C7E90518F90E24828F78EC9E0A413B36


destroy loo_Crypt
destroy loo_Sb