RsaPublicKey

RSA Public Keys

RSA Public keys are stored in JSON format and contain the following fields:

• "modulus" : The RSA modulus (n) of this public key
• "publicExponent": The RSA public exponent (e) of this public key
• "size" : The size of the modulus in bits
• "padding": The type of padding to be used. Defaults to OAEP. This Field is not implemented in Python and C++.Optional

Note: All fields are WebSafeBase64 encoded twos-complement representations of positive integers.

Possible digest sizes depend on key size and implementation. SHA1 is used by default

Key Hash

The KeyHash components are: [leftTrimZero(modulus).length] + [leftTrimZero(modulus)] + [leftTrimZero(public_exponent).length] + [leftTrimZero(public_exponent)]

If padding is PKCS don't left trim zero bytes.

Meta

{
    ...
    "purpose": ("VERIFY"|"ENCRYPT"), 
    "type": "RSA_PUB", 
    ...
}

JSON Representation

{
    "modulus": (modulus_bytes), 
    "publicExponent": (exp_bytes), 
    "size": (1024|2048|4096),
    "padding": ("OEAP"|"PKCS")
}

Supported Sizes and Key types

Java

4096, 2048, 1024 bit key sizes supported Defaults to 4096 bit key size

SHA1 is used for digests.

Python

2048, 4096, 1024, 768, 512 bit key sizes supported Defaults to 2048 bit key size.

Digest size of 256 bytes SHA1 is used for digests

C++

512, 768, 1024, 2048, 3072, 4096 key sizes supported Defaults to 2048 bit key size

If the compat flag is not set, then SHA224 is used as a digest for 2048 bit key sizes, SHA256 is used for 3072 bit key sizes, and SHA512 is used for 4096 bit keys.