COSE

Class ASN1

java.lang.Object

COSE.ASN1

public class ASN1
extends Object

Author:

Jim

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ASN1.TagValue This class is used internal to the ASN.1 decoding functions.

Field Summary

Fields

Modifier and Type	Field and Description
static byte[]	oid_ecPublicKey
static byte[]	Oid_Ed25519
static byte[]	Oid_Ed448
static byte[]	Oid_secp256r1
static byte[]	Oid_secp384r1
static byte[]	Oid_secp521r1
static byte[]	Oid_X25519
static byte[]	Oid_X448

Constructor Summary

Constructors

Constructor and Description
ASN1()

Method Summary

Modifier and Type	Method and Description
static byte[]	AlgorithmIdentifier(byte[] oid, byte[] params)
static ASN1.TagValue	DecodeCompound(int offset, byte[] encoding) Decode an array of bytes which is supposed to be an ASN.1 encoded structure.
static ArrayList<ASN1.TagValue>	DecodePKCS8(byte[] encodedData) Decode an EC PKCS#8 private key structure
static ArrayList<ASN1.TagValue>	DecodeSubjectPublicKeyInfo(byte[] encoding)
static byte[]	EncodeEcPrivateKey(byte[] oid, byte[] keyBytes, byte[] spki) Encode an EC Private key
static byte[]	EncodeOctetString(byte[] data)
static byte[]	EncodePKCS8(byte[] algorithm, byte[] keyBytes, byte[] spki) Encode a private key into a PKCS#8 private key structure.
static byte[]	EncodeSignature(byte[] r, byte[] s)
static byte[]	EncodeSubjectPublicKeyInfo(byte[] algorithm, byte[] keyBytes) Encode a subject public key info structure from an OID and the data bytes for the key This function assumes that we are encoding an EC Public key.d

Methods inherited from class java.lang.Object

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

Field Detail

Oid_secp256r1

public static final byte[] Oid_secp256r1

Oid_secp384r1

public static final byte[] Oid_secp384r1

Oid_secp521r1

public static final byte[] Oid_secp521r1

oid_ecPublicKey

public static final byte[] oid_ecPublicKey

Oid_X25519

public static final byte[] Oid_X25519

Oid_X448

public static final byte[] Oid_X448

Oid_Ed25519

public static final byte[] Oid_Ed25519

Oid_Ed448

public static final byte[] Oid_Ed448

Constructor Detail

ASN1

public ASN1()

Method Detail

EncodeSubjectPublicKeyInfo

public static byte[] EncodeSubjectPublicKeyInfo(byte[] algorithm,
                                                byte[] keyBytes)
                                         throws CoseException

Encode a subject public key info structure from an OID and the data bytes for the key This function assumes that we are encoding an EC Public key.d

Parameters:

algorithm - - encoded Object Identifier

keyBytes - - encoded key bytes

Returns:

- encoded SPKI

Throws:

CoseException - - ASN encoding error.

EncodeEcPrivateKey

public static byte[] EncodeEcPrivateKey(byte[] oid,
                                        byte[] keyBytes,
                                        byte[] spki)
                                 throws CoseException

Encode an EC Private key

Parameters:

oid - - curve to use

keyBytes - - bytes of the key

spki - - optional SPKI

Returns:

encoded private key

Throws:

CoseException - - from lower level

DecodeSubjectPublicKeyInfo

public static ArrayList<ASN1.TagValue> DecodeSubjectPublicKeyInfo(byte[] encoding)
                                                           throws CoseException

Throws:

CoseException

DecodeCompound

public static ASN1.TagValue DecodeCompound(int offset,
                                           byte[] encoding)
                                    throws CoseException

Decode an array of bytes which is supposed to be an ASN.1 encoded structure. This code does the decoding w/o any reference to a schema for what is being decoded so it returns type and value pairs rather than converting the values to the correct underlying data type. One oddity that needs to be observed is that Object Identifiers do not have the type and length removed from them. This is because we do a byte wise comparison and started doing the entire item rather than just the value portion. M00BUG - we should check that we don't overflow during the decoding process.

Parameters:

offset - - starting offset in array to begin decoding

encoding - - bytes of the ASN.1 encoded value

Returns:

Decoded structure

Throws:

CoseException - - ASN.1 encoding errors

EncodePKCS8

public static byte[] EncodePKCS8(byte[] algorithm,
                                 byte[] keyBytes,
                                 byte[] spki)
                          throws CoseException

Encode a private key into a PKCS#8 private key structure.

Parameters:

algorithm - - EC curve OID

keyBytes - - raw bytes of the key

spki - - optional subject public key info structure to include

Returns:

byte array of encoded bytes

Throws:

CoseException - - ASN.1 encoding errors

DecodePKCS8

public static ArrayList<ASN1.TagValue> DecodePKCS8(byte[] encodedData)
                                            throws CoseException

Decode an EC PKCS#8 private key structure

Parameters:

encodedData - bytes containing the private key

Returns:

tag/value from the decoded object

Throws:

CoseException - - ASN.1 encoding errors

EncodeSignature

public static byte[] EncodeSignature(byte[] r,
                                     byte[] s)
                              throws CoseException

Throws:

CoseException

EncodeOctetString

public static byte[] EncodeOctetString(byte[] data)
                                throws CoseException

Throws:

CoseException

AlgorithmIdentifier

public static byte[] AlgorithmIdentifier(byte[] oid,
                                         byte[] params)
                                  throws CoseException

Throws:

CoseException