(Tcl) PBES1 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 PBES1, which ise based on the PBKDF1 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 PBES1 encryption:

CkCrypt2_put_CryptAlgorithm $crypt "pbes1"
CkCrypt2_put_PbesPassword $crypt "mySecretPassword"

# Set the underlying PBE algorithm (and key length):
# For PBES1, the underlying algorithm must be either
# 56-bit DES or 64-bit RC2 
# (this is according to the PKCS#5 specifications at
# http://www.rsa.com/rsalabs/node.asp?id=2127   )
CkCrypt2_put_PbesAlgorithm $crypt "rc2"
CkCrypt2_put_KeyLength $crypt 64

# The salt for PBKDF1 is always 8 bytes:
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 PBES1:
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