C#

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.

C#

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

Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

//  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.

crypt.CryptAlgorithm = "aes";
crypt.KeyLength = 256;

string password = "this is my password";
crypt.SetSecretKeyViaPassword(password);

//  Examine the resulting SecretKey in hex:
Debug.WriteLine("Computed Secret Key = " + crypt.GetEncodedKey("hex"));

//  Now perform the same computation manually:
Chilkat.StringBuilder sb = new Chilkat.StringBuilder();

crypt.HashAlgorithm = "md5";
crypt.Charset = "utf-8";
crypt.EncodingMode = "hex";
sb.Append(crypt.HashStringENC(password));

string passwordBase64 = crypt.EncodeString(password,"utf-8","base64");
sb.Append(crypt.HashStringENC(passwordBase64));

Debug.WriteLine("Manually Computed = " + sb.GetAsString());

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