The %decrypt() function decrypts a string. The OpenSSL libraries must be loaded to use this function.
code = %decrypt(params, inputstring, outputstring, &outputstring length)
| code | Return code representing the result of the function. |
| params | A dynamic array containing the following information: |
| Algorithm (Supported algorithm is Crypto$Algorithm$AES128). | |
| Length of input string. | |
| Size of output buffer. | |
| Clear text key (must be 16-bytes long). If the clear text key is null, the default key will be used. | |
| inputstring | Input string. |
| outputstring | Output string. |
| outputstring length | Length of the encrypted string. |
This function returns an integer to the code variable as follows:
| 0 | Success |
| -1 | Error |
| -2 | Invalid keysize (must be 16 byte) |
| -3 | Output buffer too small. The output string buffer must be pre-allocated, and its size must be a minimum of twice the size of the input buffer for the %encrypt() function to work. The return parameter outputstring length denotes the actual length of the encrypted string. |
The example below illustrates encrypting and decrypting a user-provided string.
include dm,bp,includes nt_util.inc include dm,bp,includes crypto.inc ; crt "enter string: ":; input password crt "enter 16-char key: ":; input key char encryptedPassword[ 1 * Len( password ) ] cryptoParams = "" cryptoParams< Crypto$P$Algorithm > =Crypto$Algorithm$AES128 cryptoParams< Crypto$P$inputlength > = Len( password ) cryptoParams< Crypto$P$outputLength > = Len(encryptedPassword ) cryptoParams< Crypto$P$ClearKey > = key encryptedLen = 0 gp.result = %Encrypt( cryptoParams, password,encryptedPassword, &encryptedLen) encryptedPassword = encryptedPassword[1, encryptedLen] * * now do the decryption char decryptedPswd[Len(encryptedPassword)] cryptoParams< Crypto$P$inputLength > = encryptedLen cryptoParams< Crypto$P$outputLength > = Len(decryptedPswd ) decryptedLen = 0 gp.result = %Decrypt( cryptoParams, encryptedPassword,decryptedPswd, &decryptedLen) if (password = decryptedPswd) then print "pass" else print "fail"