Crypto.PublicKey.RSA.RSAImplementation

This class is only internally used to implement the methods of the Crypto.PublicKey.RSA modulule.

Create a new RSA key factory.

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 Note . Use the specified function directly.

Raises:

Overrides: object.__init__

Randomly generate a fresh, new RSA key object.

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.
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.

Raises:

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

Attention:

You should always use a cryptographically secure random number generator, such as the one defined in the Crypto.Random module; don't just use the current time and the random module.
Exponent 3 is also widely used, but it requires very special care when padding the message.

Construct an RSA key object 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:

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.

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

Parameters:

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

The key can be in any of the following formats:
- DER + PKCS#1 (binary)
- PEM + PKCS#1 (textual, according to RFC1421/3)
- DER + PKCS#8 (binary, private key only)
- PEM + PKCS#8 (textual, according to RFC5208, private key only)
- OpenSSH (textual public key only)
In case of PEM + PKCS#1, the 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.

Raises:

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

Class RSAImplementation