rsatool is a Python-based utility that calculates RSA cryptographic parameters including p, q, n, d, e values and RSA-CRT parameters (dP, dQ, qInv). The tool accepts input in two formats: either two prime numbers (p, q) or a modulus and private exponent (n, d). It then computes the remaining RSA parameters needed for cryptographic operations. Key features include: - Calculation of standard RSA parameters (p, q, n, d, e) - Generation of RSA-CRT parameters (dP, dQ, qInv) - Display of calculated parameters in readable format - Export functionality for OpenSSL-compatible private keys - Support for both DER and PEM encoding formats - Command-line interface for easy integration The tool requires Python 3.7 or higher and depends on the pyasn1 and gmpy2 libraries for ASN.1 encoding and mathematical operations respectively. Output can be saved to files in industry-standard formats, making it compatible with OpenSSL and other cryptographic tools that work with RSA private keys.