>I have a form that has a memo field and I need the data in that memo field to be encrypted as it has passwords and other sensitive information in it. How can I use the _crypt class library to ensure that the data is encrypted in the database file?A simple example:
x = CREATEOBJECT("docrypto")
? x.EncryptStream("This is easy", "look Ma, no hands!")
return
DEFINE CLASS docrypto AS Session
PROTECTED oCrypto
oCrypto = ""
MinimumPasswordLength = 5
PROCEDURE Init
this.oCrypto = NEWOBJECT("_cryptapi", Home(1) + "\Ffc\_crypt.vcx")
IF VARTYPE(this.oCrypto) != "O"
RETURN .f.
ENDIF
ENDPROC
PROCEDURE EncryptStream(tcString as Character, tcPassword as Character) as Character
IF PCOUNT() < 2
RETURN "Usage: EncryptStream(String, Passphrase)"
ENDIF
LOCAL lcEncryptedStream
IF EMPTY(tcString)
RETURN "Nothing to do!"
ENDIF
IF LEN(tcPassWord) < nMinimumPasswordLength
RETURN "Passphrase must >= " + TRANSFORM(nMinimumPasswordLength) + " chars!"
ENDIF
IF This.oCrypto.EncryptSessionStreamString(tcString, tcPassWord, @lcEncryptedStream)
RETURN lcEncryptedStream
ELSE
RETURN .F.
ENDIF
ENDPROC
PROCEDURE DecryptStream(tcEncryptedString as Character, tcPassWord as Character) as Character
IF PCOUNT() < 2
RETURN "Usage: DecryptStream(EncryptedString, Passphrase)"
ENDIF
LOCAL lcDecryptedString
IF EMPTY(tcEncryptedString)
RETURN "Nothing to do!"
ENDIF
IF LEN(tcPassWord) < nMinimumPasswordLength
RETURN "Passphrase must >= " + TRANSFORM(nMinimumPasswordLength) + " chars!"
ENDIF
IF This.oCrypto.DecryptSessionStreamString(tcEncryptedString, tcPassWord, @lcDecryptedString)
RETURN lcDecryptedString
ELSE
RETURN .F.
ENDIF
ENDPROC
PROCEDURE Destroy
this.oCrypto = .null.
ENDPROC
PROCEDURE Error(nError, cMethod, nLine)
RETURN MESSAGE() + " - (" + TRANSFORM(ERROR()) + ")"
ENDPROC
ENDDEFINEHTH
