Module page.codeberg.friedolyn.Friedolyn

Package page.codeberg.friedolyn.meta

Class BannedUser

java.lang.Object

page.codeberg.friedolyn.meta.BannedUser

All Implemented Interfaces:

Copyable<BannedUser>

public class BannedUser
extends Object
implements Copyable<BannedUser>

Represents a user of the Friedolyn application who has been banned from using certain features. For privacy reasons, the user's name, e-mail address, and clear name are stored as hashes, because they are published online in the PolledMetadata.

Field Summary

Fields

Modifier and Type	Field	Description
@NonNull Set<BanLevel>	banLevels	All features of the application that the user is banned from using.
private HashingResult	clearName	The Argon2 hash of the clear name of the user who was banned.
private final @NonNull ReentrantLock	DECRYPT_MESSAGE_LOCK	Facilitates mutual exclusion when decrypting the message to the user who was banned.
private String	decryptedMessage	The decrypted message to the user who was banned.
private HashingResult	email	The Argon2 hash of the e-mail address of the user who was banned.
private CipherText	message	An explanation from the developers to the user banned about why they were banned and what this means for them.
private HashingResult	username	The Argon2 hash of the user name that was banned.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	BannedUser()	Deprecated. Only to be used by Jackson during deserialisation.
	BannedUser(@NonNull Set<BanLevel> banLevels)	Creates a new BannedUser with the given ban levels.

Method Summary

Modifier and Type	Method	Description
@NonNull BannedUser	copy()
private @NonNull Optional<String>	decryptMessage(@NonNull Configuration configuration)	Decrypts the developers' message to the user, trying the user name, the e-mail address, and the clear name as the password.
boolean	equals(@NonNull Object object)	Compares this BannedUser with the given object.
@NonNull HashSet<BanLevel>	getBanLevels()
@NonNull Optional<HashingResult>	getClearName()
@NonNull Optional<String>	getDecryptedMessage()
@NonNull Optional<HashingResult>	getEmail()
@NonNull Optional<CipherText>	getMessage()
@NonNull Optional<HashingResult>	getUsername()
Result<String>	matches(@NonNull Configuration configuration)	Checks if the user corresponding to the given Configuration matches this banned user.
private boolean	matchesClearName(@NonNull Configuration configuration)	Checks if the clear name's hash matches the clearName of this banned user.
private boolean	matchesEmail(@NonNull Configuration configuration)	Checks if the e-mail address's hash matches the email of this banned user.
private boolean	matchesUser(@NonNull Configuration configuration)	Checks if the user name's hash matches the username of this banned user.
void	setBanLevels(@NonNull Set<BanLevel> banLevels)	Updates the banLevels with a deep copy of the given BanLevels that indicate which features of the application the user is not allowed to use.
private void	setClearName(@NonNull String clearNameHash)	Deprecated. Only to be used by Jackson during deserialisation.
void	setClearName(@NonNull HashingResult clearName)	Updates the clearName hash of the user who was banned.
private void	setEmail(@NonNull String emailHash)	Deprecated. Only to be used by Jackson during deserialisation.
void	setEmail(@NonNull HashingResult email)	Updates the email hash of the user who was banned.
private void	setMessage(@NonNull String message)	Deprecated. Only to be used by Jackson during deserialisation.
void	setMessage(@NonNull CipherText encryptedMessage)	Updates the message to the user who was banned.
private void	setUsername(@NonNull String usernameHash)	Deprecated. Only to be used by Jackson during deserialisation.
void	setUsername(@NonNull HashingResult username)	Updates the username hash of the user who was banned.
private void	updateBanLevels(@NonNull Set<String> banLevels)	Deprecated. Only to be used by Jackson during deserialisation.

Methods inherited from class java.lang.Object

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

Field Details

username

@Nullable
private HashingResult username

The Argon2 hash of the user name that was banned. May be null if the user name was not provided.

email

@Nullable
private HashingResult email

The Argon2 hash of the e-mail address of the user who was banned. May be null if the e-mail address was not provided.

clearName

@Nullable
private HashingResult clearName

The Argon2 hash of the clear name of the user who was banned. May be null if the clear name was not provided.

message

@Nullable
private CipherText message

An explanation from the developers to the user banned about why they were banned and what this means for them. May be null if no message was provided.

decryptedMessage

@Nullable
private String decryptedMessage

The decrypted message to the user who was banned. May be null if the message has not been decrypted yet or if the decryption failed.

DECRYPT_MESSAGE_LOCK

@NonNull
private final @NonNull ReentrantLock DECRYPT_MESSAGE_LOCK

Facilitates mutual exclusion when decrypting the message to the user who was banned.

banLevels

@NonNull
public @NonNull Set<BanLevel> banLevels

All features of the application that the user is banned from using. Won't be empty.

Constructor Details

BannedUser

public BannedUser(@NonNull
 @NonNull Set<BanLevel> banLevels)

Creates a new BannedUser with the given ban levels.

Parameters:

banLevels - The application features that the user is banned from using.

BannedUser

@Deprecated
private BannedUser()

Deprecated.

Only to be used by Jackson during deserialisation. Use BannedUser(Set) instead.

Method Details

setUsername

public void setUsername(@NonNull
 @NonNull HashingResult username)

Updates the username hash of the user who was banned.

Parameters:

username - The new hash of the user name.

setEmail

public void setEmail(@NonNull
 @NonNull HashingResult email)

Updates the email hash of the user who was banned.

Parameters:

email - The new hash of the e-mail address.

setClearName

public void setClearName(@NonNull
 @NonNull HashingResult clearName)

Updates the clearName hash of the user who was banned.

Parameters:

clearName - The new hash of the clear name.

setMessage

public void setMessage(@NonNull
 @NonNull CipherText encryptedMessage)

Updates the message to the user who was banned.

Parameters:

encryptedMessage - The new message to the user who was banned, in AES-encrypted form.

setUsername

@Deprecated
private void setUsername(@NonNull
 @NonNull String usernameHash)
                  throws IllegalArgumentException

Deprecated.

Only to be used by Jackson during deserialisation. Use (CipherText) instead.

Parameters:

usernameHash - The new hash of the user name that was banned.

Throws:

IllegalArgumentException - See HashingResult.parse(String).

setEmail

@Deprecated
private void setEmail(@NonNull
 @NonNull String emailHash)
               throws IllegalArgumentException

Deprecated.

Only to be used by Jackson during deserialisation. Use (CipherText) instead.

Parameters:

emailHash - The new hash of the e-mail address of the user who was banned.

Throws:

IllegalArgumentException - See HashingResult.parse(String).

setClearName

@Deprecated
private void setClearName(@NonNull
 @NonNull String clearNameHash)
                   throws IllegalArgumentException

Deprecated.

Only to be used by Jackson during deserialisation. Use (CipherText) instead.

Parameters:

clearNameHash - The new hash of the clear name of the user who was banned.

Throws:

IllegalArgumentException - See HashingResult.parse(String).

setMessage

@Deprecated
private void setMessage(@NonNull
 @NonNull String message)
                 throws IllegalArgumentException

Deprecated.

Only to be used by Jackson during deserialisation.

Parameters:

message - The new message to the user who was banned.

Throws:

IllegalArgumentException - See CipherText.parse(String).

updateBanLevels

@Deprecated
private void updateBanLevels(@NonNull
 @NonNull Set<String> banLevels)
                      throws IllegalArgumentException

Deprecated.

Only to be used by Jackson during deserialisation.

Parameters:

banLevels - The new ban levels that the user is banned from using.

Throws:

IllegalArgumentException - See BanLevel.valueOf(String).

setBanLevels

public void setBanLevels(@NonNull
 @NonNull Set<BanLevel> banLevels)
                  throws IllegalArgumentException

Updates the banLevels with a deep copy of the given BanLevels that indicate which features of the application the user is not allowed to use.

Parameters:

banLevels - The new bans imposed on the user. Must not be empty. Use BanLevel.LIFTED to communicate that previous bans are no longer in effect.

Throws:

IllegalArgumentException - If the given set of ban levels is empty.

getUsername

@NonNull
public @NonNull Optional<HashingResult> getUsername()

Returns:

A deep copy of the username hash of the user who was banned. Empty if no user name was provided. Either the email or the clearName hash will be present.

See Also:

• getEmail()
• getClearName()

getEmail

@NonNull
public @NonNull Optional<HashingResult> getEmail()

Returns:

A deep copy of the email hash of the user who was banned. Empty if no e-mail address was provided. Either the username or the clearName hash will be present.

See Also:

• getUsername()
• getClearName()

getClearName

@NonNull
public @NonNull Optional<HashingResult> getClearName()

Returns:

A deep copy of the clearName hash of the user who was banned. Empty if no clear name was provided. Either the username or the email hash will be present.

See Also:

• getUsername()
• getEmail()

getMessage

@NonNull
public @NonNull Optional<CipherText> getMessage()

Returns:

A deep copy of the message to the user who was banned. Empty if no message was provided.

getDecryptedMessage

@NonNull
public @NonNull Optional<String> getDecryptedMessage()

Returns:

The decrypted message to the user who was banned. Empty if the message has not been decrypted yet or if the decryption failed.

getBanLevels

@NonNull
public @NonNull HashSet<BanLevel> getBanLevels()

Returns:

A deep copy of the banLevels that the user is banned from using. Won't be empty.

matches

public Result<String> matches(@NonNull
 @NonNull Configuration configuration)

Checks if the user corresponding to the given Configuration matches this banned user.

• Configuration.getUserHash() is matched against username
• Configuration.getEmailHash() is matched against email
• Configuration.getClearnameHash() is matched against clearName

For each hash: If the respective Argon2 parameters differ, the respective hash of the Configuration is re-computed.

Message to the banned user

If the developers have attached an explanation to the banned user, it is decrypted with the user's user name as the AES password. If this fails, the decryption is tried with the user's e-mail or, if that fails too, with the user's clear name.

Parameters:

configuration - The settings of the user who shall be checked against this banned user.

Returns:

A Result that indicates whether the user matches this banned user. If the given user is, in fact, banned, success will be true. If the developers have left a message that could be decrypted, it is returned as the result.

matchesUser

private boolean matchesUser(@NonNull
 @NonNull Configuration configuration)

Checks if the user name's hash matches the username of this banned user. The hash may need to be computed first, potentially resulting in a delay.

Parameters:

configuration - The settings of the user who shall be checked against this banned user.

Returns:

true if the user name hashes match, false otherwise.

matchesEmail

private boolean matchesEmail(@NonNull
 @NonNull Configuration configuration)

Checks if the e-mail address's hash matches the email of this banned user. The hash may need to be computed first, potentially resulting in a delay.

Parameters:

configuration - The settings of the user who shall be checked against this banned user.

Returns:

true if the e-mail address hashes match, false otherwise.

matchesClearName

private boolean matchesClearName(@NonNull
 @NonNull Configuration configuration)

Checks if the clear name's hash matches the clearName of this banned user. The hash may need to be computed first, potentially resulting in a delay.

Parameters:

configuration - The settings of the user who shall be checked against this banned user.

Returns:

true if the clear name hashes match, false otherwise.

decryptMessage

@NonNull
private @NonNull Optional<String> decryptMessage(@NonNull
 @NonNull Configuration configuration)

Decrypts the developers' message to the user, trying the user name, the e-mail address, and the clear name as the password. If successful, the decrypted message is stored in the decryptedMessage field.

Parameters:

configuration - The user whose properties shall be tried as the decryption password.

Returns:

The decrypted message to the banned user. Empty if

• there is no message or
• the message had not been decrypted previously and
  • the given configuration does not match this banned user or
  • the message could not be decrypted using the user name, the e-mail address or the clear name as the password

Implementation Note:

This method is mutually exclusive, in order not to overwhelm the CPU with simultaneous decryption attempts and in order not to waste resources by doing the same decryption multiple times.

copy

@NonNull
public @NonNull BannedUser copy()

Specified by:

copy in interface Copyable<BannedUser>

Returns:

A deep copy of the object, i.e. a clone that has the exact same values as the original object, but is a different instance (new reference).

equals

public boolean equals(@NonNull
 @NonNull Object object)

Compares this BannedUser with the given object.

Overrides:

equals in class Object

Parameters:

object - The object to compare this BannedUser with.

Returns:

• true if the given object is a BannedUser whose fields' values match their equivalents in this BannedUser, especially (but not exclusively) if the given BannedUser is the exact same reference as this BannedUser.
• false if the given object is not a BannedUser or if any of the fields' values differ from their equivalents in this BannedUser.