Asymmetric Key Algorithms

Asymmetric key algorithms are encryption algorithms that use a pair of cryptographic keys, one for data encryption and signing and the other one for data decryption and signature verification.

wolfcrypt provides access to the following Asymmetric Key Ciphers:

RSA

class wolfcrypt.ciphers.RsaPublic(key)

encrypt(plaintext)

Encrypts plaintext, using the public key data in the object. The plaintext’s length must not be greater than:

self.output_size - self.RSA_MIN_PAD_SIZE

Returns a string containing the ciphertext.

verify(signature)

Verifies signature, using the public key data in the object. The signature’s length must be equal to:

self.output_size

Returns a string containing the plaintext.

class wolfcrypt.ciphers.RsaPrivate(key)

decrypt(ciphertext)

Decrypts ciphertext, using the private key data in the object. The ciphertext’s length must be equal to:

self.output_size

Returns a string containing the plaintext.

sign(plaintext)

Signs plaintext, using the private key data in the object. The plaintext’s length must not be greater than:

self.output_size - self.RSA_MIN_PAD_SIZE

Returns a string containing the signature.

encrypt(plaintext)

Encrypts plaintext, using the public key data in the object. The plaintext’s length must not be greater than:

self.output_size - self.RSA_MIN_PAD_SIZE

Returns a string containing the ciphertext.

verify(signature)

Verifies signature, using the public key data in the object. The signature’s length must be equal to:

self.output_size

Returns a string containing the plaintext.

Example:

>>> from wolfcrypt.ciphers import RsaPrivate, RsaPublic
>>> from wolfcrypt.utils import h2b
>>>
>>> private = "3082025C02010002818100BC730EA849F374A2A9EF18A5DA559921F9C8ECB36D" \
...         + "48E53535757737ECD161905F3ED9E4D5DF94CAC1A9D719DA86C9E84DC4613682" \
...         + "FEABAD7E7725BB8D11A5BC623AA838CC39A20466B4F7F7F3AADA4D020EBB5E8D" \
...         + "6948DC77C9280E22E96BA426BA4CE8C1FD4A6F2B1FEF8AAEF69062E5641EEB2B" \
...         + "3C67C8DC2700F6916865A902030100010281801397EAE8387825A25C04CE0D40" \
...         + "7C31E5C470CD9B823B5809863B665FDC3190F14FD5DB15DDDED73B9593311831" \
...         + "0E5EA3D6A21A716E81481C4BCFDB8E7A866132DCFB55C1166D279224458BF1B8" \
...         + "48B14B1DACDEDADD8E2FC291FBA5A96EF83A6AF1FD5018EF9FE7C3CA78EA56D3" \
...         + "D3725B96DD4E064E3AC3D9BE72B66507074C01024100FA47D47A7C923C55EF81" \
...         + "F041302DA3CF8F1CE6872705700DDF9835D6F18B382F24B5D084B6794F712994" \
...         + "5AF0646AACE772C6ED4D59983E673AF3742CF9611769024100C0C1820D0CEBC6" \
...         + "2FDC92F99D821A31E9E9F74BF282871CEE166AD11D188270F3C0B62FF6F3F71D" \
...         + "F18623C84EEB8F568E8FF5BFF1F72BB5CC3DC657390C1B54410241009D7E05DE" \
...         + "EDF4B7B2FBFC304B551DE32F0147966905CD0E2E2CBD8363B6AB7CB76DCA5B64" \
...         + "A7CEBE86DF3B53DE61D21EEBA5F637EDACAB78D94CE755FBD71199C102401898" \
...         + "1829E61E2739702168AC0A2FA172C121869538C65890A0579CBAE3A7B115C8DE" \
...         + "F61BC2612376EFB09D1C44BE1343396717C89DCAFBF545648B38822CF2810240" \
...         + "3989E59C195530BAB7488C48140EF49F7E779743E1B419353123759C3B44AD69" \
...         + "1256EE0061641666D37C742B15B4A2FEBF086B1A5D3F9012B105863129DBD9E2"
>>>
>>> prv = RsaPrivate(h2b(private))
>>>
>>> public  = "30819F300D06092A864886F70D010101050003818D0030818902818100BC730E" \
...         + "A849F374A2A9EF18A5DA559921F9C8ECB36D48E53535757737ECD161905F3ED9" \
...         + "E4D5DF94CAC1A9D719DA86C9E84DC4613682FEABAD7E7725BB8D11A5BC623AA8" \
...         + "38CC39A20466B4F7F7F3AADA4D020EBB5E8D6948DC77C9280E22E96BA426BA4C" \
...         + "E8C1FD4A6F2B1FEF8AAEF69062E5641EEB2B3C67C8DC2700F6916865A90203010001"
>>>
>>> pub = RsaPublic(h2b(public))
>>>
>>> plaintext = b"Everyone gets Friday off."
>>>
>>> ciphertext = pub.encrypt(plaintext)
>>> ciphertext 
b'e\xb7\xc2\xad\x0c\x04.\xefU8\x17QB\x852\x03\x01\xef\xbe=\xb4\xaf\xaf\x97\x9e4\x96\x9f\xc3\x8e\x87\x9a8o$.|_e\x1d\xa2yi?\x83\x18\xf9Yr|\x1fQ\x1a\x18\x1e\xab\xd17\xc5\x8c\xae\x08c)\xbc\nIr\x8d\xc3\x88\x7f\xde\x1f\x1a^lB\r\xf1\xc0\xfd0\xdeA\xf3\xd2\xe5q\x9a0\xee\xb4,\x97\x80\xa4|U;\xe6\x11\xf0\xc2Q\x987\xe1>F\xf5\x14\x186@G~(Q\xf2;\xcb\x05\xee\x88\x0b\xd8\xa7'
>>>
>>> prv.decrypt(ciphertext)
b'Everyone gets Friday off.'
>>>
>>> signature = prv.sign(plaintext)
>>> signature 
b'~\xc4\xe65\x15\xb17\x7fX\xaf,\xc2lw\xbd\x8f\t\x9d\xbf\xac\xdez\x90\xb4\x9f\x1aM\x88#Z\xea\xcb\xa6\xdb\x99\xf55\xd0\xfe|Mu\xb6\xb79(t\x81+h\xf2\xcd\x88v\xa8\xbaM\x86\xcfk\xe8\xf3\x0b\xb8\x8ew\xda>\xf8\xd5[H\xeaAh\xc6\xdaQlo]\xdd\xf8w\xe7#M-\x12f\xae,\xdd\xa6d FP<;R\xa2\x96hJ\xee_\x1fh\xaa\xc8\xdfAJ\xa5\xdd\x05\xc4\x89\x0c\xd7\xa0C\xb7u"U\x03'
>>>
>>> pub.verify(signature)
b'Everyone gets Friday off.'

ECC

class wolfcrypt.ciphers.EccPublic(key=None)

decode_key(key)

Decodes an ECC public key from an ASN sequence.

encode_key(with_curve=True)

Encodes the ECC public key in an ASN sequence.

Returns the encoded key.

import_x963(x963)

Imports an ECC public key in ANSI X9.63 format.

export_x963()

Exports the public key data of the object in ANSI X9.63 format.

Returns the exported key.

verify(signature, data)

Verifies signature, using the public key data in the object.

Returns True in case of a valid signature, otherwise False.

class wolfcrypt.ciphers.EccPrivate(key=None)

classmethod make_key(size, rng=<wolfcrypt.random.Random object>)

Generates a new key pair of desired length size.

decode_key(key)

Decodes an ECC private key from an ASN sequence.

encode_key()

Encodes the ECC private key in an ASN sequence.

Returns the encoded key.

shared_secret(peer)

Generates a new secret key using the private key data in the object and the peer’s public key.

Returns the shared secret.

export_x963()

Exports the public key data of the object in ANSI X9.63 format.

Returns the exported key.

import_x963(x963)

Imports an ECC public key in ANSI X9.63 format.

sign(plaintext, rng=<wolfcrypt.random.Random object>)

Signs plaintext, using the private key data in the object.

Returns the signature.

verify(signature, data)

Verifies signature, using the public key data in the object.

Returns True in case of a valid signature, otherwise False.