Class PKCS115_SigScheme

This signature scheme can perform PKCS#1 v1.5 RSA signature or verification.

Instance Methods

__init__(self, key)
Initialize this PKCS#1 v1.5 signature scheme object.

can_sign(self)
Return True if this cipher object can be used for signing messages.

sign(self, mhash)
Produce the PKCS#1 v1.5 signature of a message.

verify(self, mhash, S)
Verify that a certain PKCS#1 v1.5 signature is authentic.

Method Details

Initialize this PKCS#1 v1.5 signature scheme object.

Parameters:

key (an RSA key object) - If a private half is given, both signature and verification are possible. If a public half is given, only verification is possible.

Produce the PKCS#1 v1.5 signature of a message.

This function is named RSASSA-PKCS1-V1_5-SIGN, and is specified in section 8.2.1 of RFC3447.

Parameters:

mhash (hash object) - The hash that was carried out over the message. This is an object belonging to the Crypto.Hash module.

Returns:

The signature encoded as a string.

Raises:

ValueError - If the RSA key length is not sufficiently long to deal with the given hash algorithm.
TypeError - If the RSA key has no private half.

Verify that a certain PKCS#1 v1.5 signature is authentic.

This function checks if the party holding the private half of the key really signed the message.

This function is named RSASSA-PKCS1-V1_5-VERIFY, and is specified in section 8.2.2 of RFC3447.

Parameters:

mhash (hash object) - The hash that was carried out over the message. This is an object belonging to the Crypto.Hash module.
S (string) - The signature that needs to be validated.

Returns:

True if verification is correct. False otherwise.