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Curta Simulator [exclusive] (macOS)

Our SSL Converter allows you to quickly and easily convert SSL Certificates into 6 formats such as PEM, DER, PKCS#7, P7B, PKCS#12 and PFX. Depending on the server configuration (Windows, Apache, Java), it may be necessary to convert your SSL certificates from one format to another.


  • Microsoft Windows servers use .pfx files
  • Apache servers use .crt, .cer

If one of your certificates is not in the correct format, please use our SSL converter:

How to use the SSL converter, just select your certificate file and its current format type or drag the file extension so that the converter detects the certificate type, then select the certificate type you want to convert it to and click on Convert Certificate. For certificates with private keys select the file in the dedicated field and type your password if necessary. For more information about the different types of SSL certificates and how you can convert certificates on your computer using OpenSSL, you will find all the necessary information below.

Curta Simulator [exclusive] (macOS)

# Curta Simulator (Text-Based) # Simulates a mechanical Curta calculator (Type I) # Supports addition, subtraction, multiplication, division, and clearing

class CurtaSimulator: def __init__(self): self.register = 0 # Main register (result) self.input_digits = [] # Current input number (up to 11 digits) self.negative = False # Track sign of register def _clear_input(self): self.input_digits = [] def _get_input_value(self): """Convert current input digits to an integer""" if not self.input_digits: return 0 val = int(''.join(map(str, self.input_digits))) return val def add_digit(self, digit): """Add a digit to current input (like turning the setting knob)""" if len(self.input_digits) < 11: # Curta Type I has 11-digit capacity self.input_digits.append(digit) print(f" Input: {self._get_input_value()}") else: print(" Max 11 digits reached.") def clear_input(self): """Clear current input (CR)""" self._clear_input() print(" Input cleared.") def add(self): """Add current input to register""" val = self._get_input_value() self.register += val self._clear_input() print(f" Added {val}. Register = {self.register}") def subtract(self): """Subtract current input from register""" val = self._get_input_value() self.register -= val self._clear_input() print(f" Subtracted {val}. Register = {self.register}") def multiply(self): """Multiply register by current input (simulated)""" val = self._get_input_value() if val != 0: self.register *= val else: print(" Multiplication by zero not allowed (mechanical lock)") self._clear_input() print(f" Multiplied by {val}. Register = {self.register}") def divide(self): """Divide register by current input (simulated)""" val = self._get_input_value() if val == 0: print(" Division by zero not possible.") else: self.register /= val print(f" Divided by {val}. Register = {self.register:.6f}") self._clear_input() def clear_register(self): """Clear main register (CR)""" self.register = 0 self.negative = False print(" Register cleared.") def show(self): """Display current state""" print("\n=== Curta Status ===") print(f"Register: {self.register}") print(f"Current input: {self._get_input_value()}") print("===================") def run_cli(self): """Interactive command-line interface""" print("\n=== CURTA SIMULATOR (Type I) ===") print("Commands:") print(" #<digit> - enter digit (0-9)") print(" clr - clear current input") print(" + - add") print(" - - subtract") print(" * - multiply") print(" / - divide") print(" regclr - clear register") print(" show - show status") print(" quit - exit") print("================================\n") while True: cmd = input("> ").strip().lower() if cmd.startswith("#"): digit = cmd[1:] if digit.isdigit() and len(digit) == 1: self.add_digit(int(digit)) else: print(" Use # followed by a single digit (0-9)") elif cmd == "clr": self.clear_input() elif cmd == "+": self.add() elif cmd == "-": self.subtract() elif cmd == "*": self.multiply() elif cmd == "/": self.divide() elif cmd == "regclr": self.clear_register() elif cmd == "show": self.show() elif cmd == "quit": print("Goodbye!") break else: print(" Unknown command.") curta simulator

This simulator mimics the of the Curta, where you first set digits, then perform an operation. Perfect for understanding how this legendary pocket calculator worked! # Curta Simulator (Text-Based) # Simulates a mechanical

OpenSSL commands for your conversion

It is recommended to convert your files directly using OpenSSL commands to keep your private key secret. To do this, please use the following commands to convert your files into different formats. If this has been impossible for you, rest assured, our SSL converter ensures you complete protection of your data, which is never stored.

Convert PEM

PEM to DER

openssl x509 -outform der -in certificate.pem -out certificate.der

PEM to P7B

openssl crl2pkcs7 -nocrl -certfile certificate.cer -out certificate.p7b -certfile CACert.cer

PEM to PFX

openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt

Convert DER

DER(.crt .cer .der) to PEM

openssl x509 -inform der -in certificate.cer -out certificate.pem

DER to CER

openssl x509 -inform der -in certificat-ssl.der -out certificat-ssl.cer

Convert P7B

P7B to PEM

openssl pkcs7 -print_certs -in certificate.p7b -out certificate.cer

P7B to PFX

openssl pkcs7 -print_certs -in certificate.p7b -out certificate.cer openssl pkcs12 -export -in certificate.cer -inkey privateKey.key -out certificate.pfx -certfile CACert.cer

P7B to CER

openssl pkcs7 -print_certs -in certificat-ssl.p7b -out certificat-ssl.cer

Convert PFX

PFX to PEM

openssl pkcs12 -in certificate.pfx -out certificate.cer -nodes

Convert CER

CER to P7B

openssl crl2pkcs7 -nocrl -certfile certificat-ssl.cer -certfile cert-intermediaire.cer -certfile cert-racine.cer -out certificat-ssl.p7b

CER to PFX

openssl pkcs12 -in certificat-ssl.cer -certfile cert-intermediaire.cer -certfile cert-racine.cer -inkey cle-privee.key -export -out certificat-ssl.pfx

CER to DER

openssl x509 -in certificat-ssl.cer -outform der -out certificat-ssl.der