privacy_amplification_step1.py

import hashlib
import csv

#definitions of the functions
# converts the elements of (almost) any type from an array to int
def array_to_int(input_arr):
    #int_arr = []
    for i in range(0, len(input_arr)):
        input_arr[i] = int(input_arr[i])
    return input_arr

def read_input_from_file(foldername, foldername2, filename):
    data_file_path = foldername + "/" + filename
    print ("Reading the file located at: ", data_file_path)
    #checks if the file exists
    try:
        with open(data_file_path, "r") as file: #open file to read
            #csvreader = csv.reader(file, delimiter=',') #creating a csv reader object
            csvreader = csv.reader(file, delimiter=',', quoting=csv.QUOTE_NONNUMERIC) #creating a csv reader object (reads the numbers as floats, not as strings)
            for row in csvreader:
                binary_key = row
            file.close() #close file
        print ("The reading process is done!")
    #if the file does not exist, tries to read the file from the other folder
    except FileNotFoundError:
        try:
            print (f"The file {filename} was not found inside {foldername}")
            data_file_path = foldername2 + "/" + filename
            print (f"Trying to check if the file located at: {data_file_path} exists...")
            
            with open(data_file_path, "r") as file: #open file to read
                #csvreader = csv.reader(file, delimiter=',') #creating a csv reader object
                csvreader = csv.reader(file, delimiter=',', quoting=csv.QUOTE_NONNUMERIC) #creating a csv reader object (reads the numbers as floats, not as strings)
                for row in csvreader:
                    binary_key = row
                file.close() #close file
            print ("Yes, it does.\nThe reading process is done!")
        #if it still not found, prints a message and closes the program
        except FileNotFoundError:
            print (f"The file {filename} was not found!\nPlease, check the name, make sure it exists and try again.")
            exit(code=2) #TODO change that to something that makes the entire program stop (as this file can be used by other programs in the future)
    finally:
        binary_key = bytearray(array_to_int(binary_key)) #converts the input array to a bytearray
        return binary_key

def write_hex_digest_to_file(digest, foldername, filename):
    results_path = foldername + "/" + filename
    print ("Writing the digest to the file located at: ", results_path)
    with open(results_path, "w") as file: #open file to write
        file.write(digest) #writing the digest to the file
        file.close() #close file
    print ("The writing process is done!")

def main(fileName):
    #updates dynamic variables
    filename = fileName

    #env vars declaration
    hash_codec = hashlib.new('sha512') #uses the OpenSSL implementation
    #files and paths to be used by the program
    #filename = "DaCruz2021-preliminar1-cut-tab-1" #filename to be used by the program
    file_format = ".csv"
    results_foldername = "results"
    #results_file_format = ".bin" #file format for the results file
    keys_foldername = results_foldername + "/" + "key-after-reconciliation" #folder to get the input key
    keys_backup_foldername = results_foldername + "/" + "key-reconciliation" #folder to get the input key
    keys_filename = "keys_" + filename + file_format #filename for the file with the key
    digest_file_format = ".txt" #file format for the results file
    digest_foldername = results_foldername + "/" + "privacy-amplification-digest" #folder to save the digest
    digest_filename = "digest_" + filename + digest_file_format #filename for the file with the digest

    #execution starts here
    input = read_input_from_file(keys_foldername, keys_backup_foldername, keys_filename)
    hash_codec.update(input) #NOTE: input must be of byte type
    hash_digest = hash_codec.digest()
    hash_hex_digest = hash_codec.hexdigest()
    #hash_size = hash_codec.digest_size

    print("The input was: ", input) #DEBUG
    print("Input's length: ", len(input), " bytes") #DEBUG
    #print("Digest size: ", hash_size, " bytes (", hash_size * 8, " bits )") #if using SHA3-512 should be always 512 bits #DEBUG
    print("The hash digest is: ", hash_digest) #DEBUG
    print("The hash hex digest is: ", hash_hex_digest) #DEBUG

    write_hex_digest_to_file(hash_hex_digest, digest_foldername, digest_filename)

# checks if the file is being run directly to avoid running it mistakenly
if __name__ == "__main__":
    main()