Package net.openid.appauth

Class CodeVerifierUtil

java.lang.Object

net.openid.appauth.CodeVerifierUtil

public final class CodeVerifierUtil
extends Object

Generates code verifiers and challenges for PKCE exchange.

See Also:

“Proof Key for Code Exchange by OAuth Public Clients (RFC 7636) https://tools.ietf.org/html/rfc7636”

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_CODE_VERIFIER_ENTROPY	The default entropy (in bytes) used for the code verifier.
static int	MAX_CODE_VERIFIER_ENTROPY	The maximum permitted entropy (in bytes) for use with generateRandomCodeVerifier(SecureRandom,int).
static int	MAX_CODE_VERIFIER_LENGTH	The maximum permitted length for a code verifier.
static int	MIN_CODE_VERIFIER_ENTROPY	The minimum permitted entropy (in bytes) for use with generateRandomCodeVerifier(SecureRandom,int).
static int	MIN_CODE_VERIFIER_LENGTH	The minimum permitted length for a code verifier.

Method Summary

Modifier and Type	Method	Description
static void	checkCodeVerifier(String codeVerifier)	Throws an IllegalArgumentException if the provided code verifier is invalid.
static String	deriveCodeVerifierChallenge(String codeVerifier)	Produces a challenge from a code verifier, using SHA-256 as the challenge method if the system supports it (all Android devices should support SHA-256), and falls back to the "plain" challenge type if unavailable.
static String	generateRandomCodeVerifier()	Generates a random code verifier string using SecureRandom as the source of entropy, with the default entropy quantity as defined by DEFAULT_CODE_VERIFIER_ENTROPY.
static String	generateRandomCodeVerifier(SecureRandom entropySource, int entropyBytes)	Generates a random code verifier string using the provided entropy source and the specified number of bytes of entropy.
static String	getCodeVerifierChallengeMethod()	Returns the challenge method utilized on this system: typically SHA-256 if supported by the system, plain otherwise.

Methods inherited from class java.lang.Object

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

Field Detail

MIN_CODE_VERIFIER_LENGTH

public static final int MIN_CODE_VERIFIER_LENGTH

The minimum permitted length for a code verifier.

See Also:

“Proof Key for Code Exchange by OAuth Public Clients (RFC 7636), Section 4.1 https://tools.ietf.org/html/rfc7636#section-4.1”, Constant Field Values

MAX_CODE_VERIFIER_LENGTH

public static final int MAX_CODE_VERIFIER_LENGTH

The maximum permitted length for a code verifier.

See Also:

“Proof Key for Code Exchange by OAuth Public Clients (RFC 7636), Section 4.1 https://tools.ietf.org/html/rfc7636#section-4.1”, Constant Field Values

DEFAULT_CODE_VERIFIER_ENTROPY

public static final int DEFAULT_CODE_VERIFIER_ENTROPY

The default entropy (in bytes) used for the code verifier.

See Also:

Constant Field Values

MIN_CODE_VERIFIER_ENTROPY

public static final int MIN_CODE_VERIFIER_ENTROPY

The minimum permitted entropy (in bytes) for use with generateRandomCodeVerifier(SecureRandom,int).

See Also:

Constant Field Values

MAX_CODE_VERIFIER_ENTROPY

public static final int MAX_CODE_VERIFIER_ENTROPY

The maximum permitted entropy (in bytes) for use with generateRandomCodeVerifier(SecureRandom,int).

See Also:

Constant Field Values

Method Detail

checkCodeVerifier

public static void checkCodeVerifier(String codeVerifier)

Throws an IllegalArgumentException if the provided code verifier is invalid.

See Also:

“Proof Key for Code Exchange by OAuth Public Clients (RFC 7636), Section 4.1 https://tools.ietf.org/html/rfc7636#section-4.1”

generateRandomCodeVerifier

public static String generateRandomCodeVerifier()

Generates a random code verifier string using SecureRandom as the source of entropy, with the default entropy quantity as defined by DEFAULT_CODE_VERIFIER_ENTROPY.

generateRandomCodeVerifier

public static String generateRandomCodeVerifier(SecureRandom entropySource,
                                                int entropyBytes)

Generates a random code verifier string using the provided entropy source and the specified number of bytes of entropy.

deriveCodeVerifierChallenge

public static String deriveCodeVerifierChallenge(String codeVerifier)

Produces a challenge from a code verifier, using SHA-256 as the challenge method if the system supports it (all Android devices should support SHA-256), and falls back to the "plain" challenge type if unavailable.

getCodeVerifierChallengeMethod

public static String getCodeVerifierChallengeMethod()

Returns the challenge method utilized on this system: typically SHA-256 if supported by the system, plain otherwise.