(Tcl) Create a Hash Signature for Value Added Tax Audit SOAP Message for Angola

Demonstrates how to create a hash signature that is required in Value Added Tax Audit Files in Angola, Africa.

It is the following two instructions that should be used to create a hash value to be put into a <hash></hash> field in SOAP XML file containing the tax data for the VAT authorities:

openssl dgst -shal -sign private.pem -outRegisto1.shal Registo1.txt

then

openssl enc -base64 - in Registo1.shal -out Registo1.b64 -A

Chilkat Tcl Extension Downloads Chilkat Tcl Extension Downloads

load ./chilkat.dll

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

set pkey [new_CkPrivateKey]

# Load the private key from an PEM file.
# Provide the password in the 2nd argument.
# If no password is needed, just pass an empty string.
set success [CkPrivateKey_LoadAnyFormatFile $pkey "qa_data/rsa/rsaPrivKey_secret.pem" "secret"]
if {$success != 1} then {
    puts [CkPrivateKey_lastErrorText $pkey]
    delete_CkPrivateKey $pkey
    exit
}

# Assuming this is an RSA private key..
set rsa [new_CkRsa]

# Import the private key into the RSA object:
set success [CkRsa_ImportPrivateKeyObj $rsa $pkey]
if {$success != 1} then {
    puts [CkRsa_lastErrorText $rsa]
    delete_CkPrivateKey $pkey
    delete_CkRsa $rsa
    exit
}

# OpenSSL uses big-endian.
CkRsa_put_LittleEndian $rsa 0

# SHA1 hash and sign, and return base64.
CkRsa_put_EncodingMode $rsa "base64"
set b64sig [CkRsa_signStringENC $rsa "2018-05-18,2018-05-18T11:22:19;FAC 001/18;53.00;" "sha1"]
puts "$b64sig"

# The signature is equal in size to your private key.  For example, if you have a 1024-bit RSA key,
# then 1024 bits = 128 bytes.   When 128 bytes is base64 encoded, the result is a string approximately
# 4/3rds the size of the original.  128 * 4 / 3 = (approximately) 172 bytes.

# If your RSA key is 2048-bits, then your signature will be twice as long.

delete_CkPrivateKey $pkey
delete_CkRsa $rsa