CapeSoft CryptoNite Class Reference
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Introduction |
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CryptoNite provides encryption and decryption in your applications for security, safe data transfer etc. Cryptonite completely removes the complexity of implementing cryptography. Cryptonite aims to make using encryption as simple as possible, and handles all the complexity for you. CryptoNite requires CryptoNite. CryptoNite will easily help you:
Classes The main CryptoNite class, handles the primary encryption and decryption tasks, as well as hashing, encoding, loading and saving data etc.. Blowfish Provides Blowfish encryption and decryption. Blowfish is a symmetric key cipher - the same key (password) is used to encrypt and decrypt the data. The CryptoNite class provides methods for creating a Blowfish object and encrypting and decrypting data. Typically the Blowfish class does not need to be used directly, as CryptoNite provides method that encapsulate this functionality, see the BlowFish Section for more information. CryptoIni A replacement class for the standard ABC INI manager. Provides the ability to encrypt and decrypt fields in the file. CryptoNiteCallback The CryptoNiteCallback implements the ABC FileCallBackInterface interface to allow on the fly encryption and decryption of fields within tables, regardless of the backend. Important: Because of a bug in the SoftVelocity SQL driver, version of Clarion prior to C6.3 9057 cannot use the FileCallBackInterface with SQL, as the REGET function will not cause the callback to be fired. This only applies to applications that use the SQL file driver.
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CryptoNite |
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Using the CryptoNite Class
In general a CryptoNite object is declared as simply as
st CryptoNite
Where st is the label name (and can be almost anything.) The length of the string is undefined, and is dynamic. In other words the string will automatically grow, and shrink as required. You do not need to worry about the length.
Values are assigned into the string using the SetValue method, or by loading a file off the disk using the LoadFile method.
st.SetValue('hello world')
st.LoadFile('c:\windows\win.ini')
After that the string can be manipulated in a number of different ways, using the methods described below. For example to Base64 encode the string;
st.Base64Encode()
Blowfish Encryption and Decryption Methods
The CryptoNite class supports BlowFish encryption and decryption of strings and files. This uses the csBlowFish class that is a part of CryptoNite.
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The plainText (the data being encrypted) can contain binary data, not just plain text data
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The cipherText (encrypted data) is binary data. To store it in ASCII text form call the Base64Encode method convert it to Base64 encoded data.
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The cipherText is always the same size as the plainText is (the data size is maintained when encrypting and decrypting, so both forms are the same length). This is not true of Base64 encoding, which increases the data size when performning encoding. The Base64Encode method handles automatically increasing the size of the string when encoding for you.
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The data being encryped (or decrypted) must always be a multiple of 8 bytes (characters) long. Future releases will support CBC mode for encrypting strings of arbitrary length and for improved security when encrypting more than 1 block of data (8 bytes) at a time.
Encryption and Decryption Examples
An example of encrypting and Base64 encoding a string using the CryptoNite object.
s
CryptoNite
password
string(256)
code
! Initialise the Blowfish
object and set the key
s.InitBlowfish('j.vnhK/xNf6\$rtYidR\v;o#^bubRL`.vf?/lVa_lawDE^I#XT1!C!n3')
password = 'My Secret Password
String!'
! Note: This can be binary data, not just
text
! Encrypt and Base64 encode a
string
s.SetValue(password)
s.Encrypt()
s.Base64Encode()
password = s.GetValue()
! password now contains
encrypted, Base64 encoded data.
! Encrypt and Base64 encode a
string
s.SetValue(password, True)
! Set the value, allow clipping (only
for text or base64 encode strings!)
s.Base64Decode()
s.Decrypt()
password = s.GetValue()
! password now contains the original value
See the methods below for additional
examples.
InitBlowfish Procedure (string key)
Initialises the Blowfish object. This must be called before any of the other Blowfish methods are used.
Parameters
key
The key to use for encryption. This string contains a binary value and can be up to 56 bytes (characters) long (448bit). Typically you should provide a string that is exactly 56 bytes in length.
Return Value
Returns True (1) if succesful and False (0) if encryption fails.
Example
s
CryptoNite
plainText
string(256)
! unencrypted value
cipherText
string(256)
! encrypted value
code
s.InitBlowfish('j.vnhK/xNf6\$rtYidR\v;o#^bubRL`.vf?/lVa_lawDE^I#XT1!C!n3')
plainText = 'Shhh, it's a
secret!'
s.EncryptString(plainText, cipherText)
Cleans up and deallocates memory. Will be called automatically when the CryptoNite object is destroyed.
Encrypts the current value stored in the CryptoNite object. See Important Notes for more information.
Return Value
Returns True (1) if succesful and False (0) if encryption fails.
Decrypts the current value stored in the CryptoNite object. See Important Notes for more information.
Return Value
Returns True (1) if succesful and False (0) if encryption fails.
bfEncryptString Procedure (*string plainText, *string cipherText)
Encrypts the passed plainText string and stores the encrypted data in the passed cipherText string. See Important Notes for more information. The cipherText string should be at least the same length as the plainText string in order to store the encrypted data.
Parameters
plainText
A string to store the decrypted data that results from decrypting the passed cipherText.
cipherText
The data to decrypt
Return Value
Returns True (1) if succesful and False (0) if encryption fails.
Example
s
CryptoNite
code
s.InitBlowfish('j.vnhK/xNf6\$rtYidR\v;o#^bubRL`.vf?/lVa_lawDE^I#XT1!C!n3')
s.EncryptString(plainText, cipherText)
bfDecryptString Procedure (*string plainText, *string cipherText)
Decrypts the passed cipherText string and stores the decrypted data in the passed plainText string. See Important Notes for more information. The plainText string should be at least the same length as the chipherText string in order to hold the data.
Parameters
plainText
A string to store the decrypted data that results from decrypting the passed cipherText.
cipherText
The data to decrypt
Return Value
Returns True (1) if succesful and False (0) if encryption fails.
Example
s
CryptoNite
code
s.InitBlowfish('j.vnhK/xNf6\$rtYidR\v;o#^bubRL`.vf?/lVa_lawDE^I#XT1!C!n3')
s.DecryptString(plainText, cipherText)
bfSetKey Procedure (string key)
Sets the key stored by the object for encryption. The key is initially set when the InitBlowfish method is called, however this can be used to change the key being used after the object has been initialised.
Parameters
key
The key to use for encryption. This string contains a binary value and can be up to 56 bytes (characters) long (448bit). Typically you should provide a string that is exactly 56 bytes in length.
CryptoNite Property Reference