Class CoseKey

java.lang.Object
com.codename1.backend.security.webauthn.CoseKey
public final class CoseKey extends Object

A credential's public key as an authenticator sends it -- a COSE_Key, RFC 9052 -- turned into what Crypto.verify(String, byte[], byte[], byte[]) takes: an algorithm name and a SubjectPublicKeyInfo.

Two kinds of key are read, the two every platform authenticator offers:

COSE algorithm Key Verified as
-7, ES256 EC2 on P-256, uncompressed Crypto.ES256
-257, RS256 RSA of 2048 bits or more Crypto.RS256

Any other algorithm is refused with WebAuthnException.UNSUPPORTED_ALGORITHM -- EdDSA (-8) among them, which the server's cryptography does not verify -- and a key that names one of the two and is not such a key with WebAuthnException.INVALID_KEY. The registration options offer only these two, so a conforming authenticator answers with nothing else.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final long
    ES256
    The COSE identifier of ES256: ECDSA on P-256 with SHA-256.
    static final long
    RS256
    The COSE identifier of RS256: RSASSA-PKCS1-v1_5 with SHA-256.

  • Method Summary

    Modifier and Type
    Method
    Description
    long
    getAlgorithm()
    The COSE identifier of the key's algorithm: ES256 or RS256.
    byte[]
    getPublicKey()
    The key as a SubjectPublicKeyInfo, in DER.
    static CoseKey
    of(long algorithm, byte[] publicKey)
    The key read from stored bytes: what getPublicKey() returned.
    boolean
    verify(byte[] data, byte[] signature)
    Whether signature is this key's signature of data.

    Methods inherited from class Object

    clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • ES256

      public static final long ES256
      The COSE identifier of ES256: ECDSA on P-256 with SHA-256.
      See Also:

    • RS256

      public static final long RS256
      The COSE identifier of RS256: RSASSA-PKCS1-v1_5 with SHA-256.
      See Also:

  • Method Details

    • of

      public static CoseKey of(long algorithm, byte[] publicKey)

      The key read from stored bytes: what getPublicKey() returned.

    • getAlgorithm

      public long getAlgorithm()
      The COSE identifier of the key's algorithm: ES256 or RS256.

    • getPublicKey

      public byte[] getPublicKey()
      The key as a SubjectPublicKeyInfo, in DER.

    • verify

      public boolean verify(byte[] data, byte[] signature)

      Whether signature is this key's signature of data. An ES256 signature is ASN.1 DER, as an authenticator sends it.