Class RSAImplementation

Parameters:

• use_fast_math (bool) - Specify which mathematic library to use:

  • None (default). Use fastest math available.
  • True . Use fast math.
  • False . Use slow math.

• default_randfunc (callable) - Specify how to collect random data:

  • None (default). Use Random.new().read().
  • not None . Use the specified function directly.

Raises:

• RuntimeError - When use_fast_math =True but fast math is not available.

Overrides: object.__init__

Parameters:

• bits (int) - Key length, or size (in bits) of the RSA modulus. It must be a multiple of 256, and no smaller than 1024.
• randfunc (callable) - Random number generation function; it should accept a single integer N and return a string of random data N bytes long. If not specified, a new one will be instantiated from Crypto.Random.
• progress_func (callable) - Optional function that will be called with a short string containing the key parameter currently being generated; it's useful for interactive applications where a user is waiting for a key to be generated.
• e (int) - Public RSA exponent. It must be an odd positive integer. It is typically a small number with very few ones in its binary representation. The default value 65537 (= 0b10000000000000001 ) is a safe choice: other common values are 5, 7, 17, and 257.

Returns:

An RSA key object (_RSAobj).

Raises:

• ValueError - When bits is too little or not a multiple of 256, or when e is not odd or smaller than 2.

Construct an RSA key from a tuple of valid RSA components.

The modulus n must be the product of two primes. The public exponent e must be odd and larger than 1.

In case of a private key, the following equations must apply:

• e != 1
• p*q = n
• e*d = 1 mod (p-1)(q-1)
• p*u = 1 mod q

Parameters:

• tup (tuple) - A tuple of long integers, with at least 2 and no more than 6 items. The items come in the following order:

  1. RSA modulus (n).
  2. Public exponent (e).
  3. Private exponent (d). Only required if the key is private.
  4. First factor of n (p). Optional.
  5. Second factor of n (q). Optional.
  6. CRT coefficient, (1/p) mod q (u). Optional.

Returns:

An RSA key object (_RSAobj).

Import an RSA key (public or private half), encoded in standard form.

Parameters:

• externKey (string) - The RSA key to import, encoded as a string.

  An RSA public key can be in any of the following formats:

  • X.509 subjectPublicKeyInfo DER SEQUENCE (binary or PEM encoding)
  • PKCS#1 RSAPublicKey DER SEQUENCE (binary or PEM encoding)
  • OpenSSH (textual public key only)

  An RSA private key can be in any of the following formats:

  • PKCS#1 RSAPrivateKey DER SEQUENCE (binary or PEM encoding)
  • PKCS#8 PrivateKeyInfo DER SEQUENCE (binary or PEM encoding)
  • OpenSSH (textual public key only)

  For details about the PEM encoding, see RFC1421/RFC1423.

  In case of PEM encoding, the private key can be encrypted with DES or 3TDES according to a certain pass phrase. Only OpenSSL-compatible pass phrases are supported.

• passphrase (string) - In case of an encrypted PEM key, this is the pass phrase from which the encryption key is derived.

Returns:

An RSA key object (_RSAobj).

Raises:

• ValueError/IndexError/TypeError - When the given key cannot be parsed (possibly because the pass phrase is wrong).