(Tcl) PBES2 Password-Based Encryption (PBE)

Demonstrates how to implement password-based encryption according to the PKCS #5 v2.0: Password-Based Cryptography Standard (published by RSA Laboratories). This example uses PBES2, which ise based on the PBKDF2 function and an underlying block cipher such as RC2, DES, etc.

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load ./chilkat.dll

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

set crypt [new_CkCrypt2]

# Set properties for PBES2 encryption:

CkCrypt2_put_CryptAlgorithm $crypt "pbes2"
CkCrypt2_put_PbesPassword $crypt "mySecretPassword"

# Set the underlying PBE algorithm (and key length):
CkCrypt2_put_PbesAlgorithm $crypt "rc2"
CkCrypt2_put_KeyLength $crypt 128
# Only required for the RC2 algorithm:
CkCrypt2_put_Rc2EffectiveKeyLength $crypt 128

# By definition, the block encryption algorithm (RC2 or whichever
# was selected) will run in CBC mode.  Therefore, we need
# an IV.  The IV is equal in length to the block size of the
# algorithm.  RC2 has a block size of 8 bytes (regardless of
# key length), so set the IV to some value that is 8 bytes 
# in length:
CkCrypt2_SetEncodedIV $crypt "0000000000000000" "hex"

# Give it some salt:
CkCrypt2_SetEncodedSalt $crypt "0102030405060708" "hex"

# A higher iteration count makes the algorithm more
# computationally expensive and therefore exhaustive
# searches (for breaking the encryption) is more difficult:
CkCrypt2_put_IterationCount $crypt 1024

# A hash algorithm needs to be set for PBES2:
CkCrypt2_put_HashAlgorithm $crypt "sha1"

# Indicate that the encrypted bytes should be returned
# as a hex string:
CkCrypt2_put_EncodingMode $crypt "hex"

set plainText "To be encrypted."

set encryptedText [CkCrypt2_encryptStringENC $crypt $plainText]

puts "$encryptedText"

# Now decrypt:
set decryptedText [CkCrypt2_decryptStringENC $crypt $encryptedText]

puts "$decryptedText"

delete_CkCrypt2 $crypt