(Tcl) Encrypt with Chilkat, Decrypt with OpenSSL

Demonstrates how to RSA encrypt a string using Chilkat, and then shows the corresponding OpenSSL command to RSA decrypt. The OpenSSL command to decrypt is as follows:

openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

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load ./chilkat.dll

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

set rsa [new_CkRsa]

# Note: RSA encryption uses the public key.  
# RSA decryption uses the private key.
# The reason is that the public key can be freely provided to anybody.  This allows anybody
# to send an encrypted message to the private key owner, and only the private key owner 
# can decrypt.
set key [new_CkPublicKey]

# Load an RSA public key from a PEM file:
set success [CkPublicKey_LoadFromFile $key "qa_data/pem/VP_Public.pem"]
if {$success != 1} then {
    puts [CkPublicKey_lastErrorText $key]
    delete_CkRsa $rsa
    delete_CkPublicKey $key
    exit
}

# Load the public key into the RSA object.
set success [CkRsa_ImportPublicKeyObj $rsa $key]
if {$success != 1} then {
    puts [CkRsa_lastErrorText $rsa]
    delete_CkRsa $rsa
    delete_CkPublicKey $key
    exit
}

set strToEncrypt "00000000;XYZ2-3BHQ-ABCD-MMVV;6MY1-GHJK-9LRR;0"

# The LittleEndian property is 0 by default, but it is set here
# anyway to show that LittleEndian byte ordering is required for OpenSSL compatibility.
CkRsa_put_LittleEndian $rsa 0

set usePrivateKey 0
set encryptedBytes [new_CkByteData]

set success [CkRsa_EncryptString $rsa $strToEncrypt $usePrivateKey $encryptedBytes]
if {[CkRsa_get_LastMethodSuccess $rsa] != 1} then {
    puts [CkRsa_lastErrorText $rsa]
    delete_CkRsa $rsa
    delete_CkPublicKey $key
    delete_CkByteData $encryptedBytes
    exit
}

# The OpenSSL command to decrypt would be this:
# openssl rsautl -decrypt -inkey VP_Private.pem -in rsa_encrypted.bin -out original.txt

set fac [new_CkFileAccess]

set success [CkFileAccess_WriteEntireFile $fac "qa_output/rsa_encrypted.bin" $encryptedBytes]
if {$success != 1} then {
    puts [CkFileAccess_lastErrorText $fac]
    delete_CkRsa $rsa
    delete_CkPublicKey $key
    delete_CkByteData $encryptedBytes
    delete_CkFileAccess $fac
    exit
}

puts "RSA Encryption Succeeded."

delete_CkRsa $rsa
delete_CkPublicKey $key
delete_CkByteData $encryptedBytes
delete_CkFileAccess $fac