net.openid.appauth

Class CodeVerifierUtil

java.lang.Object

net.openid.appauth.CodeVerifierUtil

public 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)

Field Summary

Fields

Modifier and Type	Field and 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 and Description
static void	checkCodeVerifier(String codeVerifier) Throws an IllegalArgumentException if the provided code verifier is invalid, as defined by the PKCE specification (Section 4.1).
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, 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, 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:

"Proof Key for Code Exchange by OAuth Public Clients" (RFC 7636), 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, as defined by the PKCE specification (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.

See Also:

"Proof Key for Code Exchange by OAuth Public Clients" (RFC 7636)

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.

See Also:

"Proof Key for Code Exchange by OAuth Public Clients" (RFC 7636)

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.