Xbase++

AES and CHACHA20 Encrypt/Decrypt Text

See more Encryption Examples

Demonstrates the use of the new EncryptSb and DecryptSb methods introduced in Chilkat v9.5.0.67 to encrypt/decrypt the contents of StringBuilder objects.

Note: This example requires Chilkat v9.5.0.67 or greater.

Xbase++

LOCAL nSuccess
LOCAL oSb
LOCAL i
LOCAL oCrypt
LOCAL cIvHex
LOCAL cKeyHex
LOCAL oBdEncrypted
LOCAL oSbOriginal

nSuccess := 0

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

//  First build a string to be encrypted
oSb := CreateObject("Chilkat.StringBuilder")
i := 1
DO WHILE i < 10
    oSb:AppendInt(i)
    oSb:Append(" the quick brown fox jumped over the lazy dog." + Chr(13) + Chr(10))
    i := i + 1
ENDDO

? oSb:GetAsString()

//  The string to be encrypted looks like this:

//  1 the quick brown fox jumped over the lazy dog.
//  2 the quick brown fox jumped over the lazy dog.
//  3 the quick brown fox jumped over the lazy dog.
//  4 the quick brown fox jumped over the lazy dog.
//  5 the quick brown fox jumped over the lazy dog.
//  6 the quick brown fox jumped over the lazy dog.
//  ...

oCrypt := CreateObject("Chilkat.Crypt2")

//  Specify the encryption to be used.
//  First we'll do AES-128 CBC
oCrypt:CryptAlgorithm := "aes"
oCrypt:CipherMode := "cbc"
oCrypt:KeyLength := 128

cIvHex := "000102030405060708090A0B0C0D0E0F"
oCrypt:SetEncodedIV(cIvHex, "hex")

cKeyHex := "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F"
oCrypt:SetEncodedKey(cKeyHex, "hex")

//  When EncryptSb is called, the contents of the source (sb)
//  remains unmodified.  The encrypted bytes are written into bdEncrypted.
//  If bdEncrypted already contained data, it is replaced with the encrypted bytes.
oBdEncrypted := CreateObject("Chilkat.BinData")
nSuccess := oCrypt:EncryptSb(oSb, oBdEncrypted)
IF (nSuccess != 1)
    ? oCrypt:LastErrorText
    oSb:destroy()
    oCrypt:destroy()
    oBdEncrypted:destroy()
    RETURN
ENDIF

//  Examine the encrypted bytes:
? oBdEncrypted:GetEncoded("base64_mime")

//  Sample encrypted data:

//  0DdNZ22ckMMJBiaKhAu3wUEfh16XW356NIUsDmNs/xwbHe/p1201OmpfzwXwKktkAefu2pckrBgC
//  df+1w8lRo+KAy5n5wlAgMGM/UrsVJsp0BmDPk1vaxKrmrGpSXOVCQs1n2+0atIs5YLiOG+Va3+Mi
//  EQNb4YK7bNMmvt0++irBxTiGnkx/RncfKwgkbBUpl2x7yV13MW6lapDT6Md0DKAMsTXFJYGeIdEf
//  g2uxDDQzI5gUOUHTMrXQ8paD/K76KKB9Jpp/kAM9z8g/d8KUmuphA7KI64d38xsgOmcITlbhlCQ2
//  PDkcU6RRzX0FUTUSMgQukhy0jkLZEjHX9poKJD+iJTOkcQUC3OqR9hKhSrvIgJN4lxdR71MheOoQ
//  2wmvRdq+agTWWh333Vmb6J6yDV79aSpnqEDrA8Ks7Xzciol0gve91+JtVJlJKjWwEzWEU8GxF7Q8
//  eaWI70lsC5nTLGcbqgKu6gzkzHlHyHaE2FAQA/d5I2dvfsAYUQCza0Zdyw8mmTtHhlP2Tfxj1uPv
//  H4Q7BGuKnx3SWT2CnpbX4091w7KzLAztrbFBo/Tf9w8ZpgTK9k1ryfW9/xnk6rW6iQ==

//  Decrypt to restore back to the original:
oSbOriginal := CreateObject("Chilkat.StringBuilder")
nSuccess := oCrypt:DecryptSb(oBdEncrypted, oSbOriginal)
IF (nSuccess != 1)
    ? oCrypt:LastErrorText
    oSb:destroy()
    oCrypt:destroy()
    oBdEncrypted:destroy()
    oSbOriginal:destroy()
    RETURN
ENDIF

//  Examine the original data:
? oSbOriginal:GetAsString()

//  ----------------------------------------------------------------------------------
//  To do chacha20 encryption, just change the settings:

oCrypt:CryptAlgorithm := "chacha20"
oCrypt:KeyLength := 256
//  The initial count is the initial block counter for the chacha20 algorithm.
//  It can be any integer, but must be set to the same when decrypting.
oCrypt:InitialCount := 22

//  EncryptSb completely replaces the contents of bdEncrypted.
nSuccess := oCrypt:EncryptSb(oSb, oBdEncrypted)

//  However.. DecryptSb appends the decrypted text to whatever may
//  have already existed within sbOriginal.
nSuccess := oCrypt:DecryptSb(oBdEncrypted, oSbOriginal)

? "----"
? "The original data should be here twice.  Once from the AES decrypt, and again from the chacha20 decrypt."
? oSbOriginal:GetAsString()
? "Success."

oSb:destroy()
oCrypt:destroy()
oBdEncrypted:destroy()
oSbOriginal:destroy()