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/**
* OWASP Enterprise Security API (ESAPI)
*
* This file is part of the Open Web Application Security Project (OWASP)
* Enterprise Security API (ESAPI) project. For details, please see
* http://www.owasp.org/index.php/ESAPI.
*
* Copyright © 2007-2019 - The OWASP Foundation
*
* The ESAPI is published by OWASP under the BSD license. You should read and accept the
* LICENSE before you use, modify, and/or redistribute this software.
*
* @author Jeff Williams Aspect Security
* @author [email protected]
* @created 2007
*/
package org.owasp.esapi;
import javax.crypto.SecretKey;
import org.owasp.esapi.crypto.CipherText;
import org.owasp.esapi.crypto.PlainText;
import org.owasp.esapi.errors.EncryptionException;
import org.owasp.esapi.errors.IntegrityException;
/**
* The Encryptor interface provides a set of methods for performing common
* encryption, random number, and hashing operations. Implementations should
* rely on a strong cryptographic implementation, such as JCE or BouncyCastle.
* Implementors should take care to ensure that they initialize their
* implementation with a strong "master key", and that they protect this secret
* as much as possible.
*
* The main property controlling the selection of the implementation class is the
* property {@code ESAPI.Encryptor} in {@code ESAPI.properties}. Most of the
* the other encryption related properties have property names that start with
* the string "Encryptor.". These properties all you to do things such as
* select the encryption algorithms, the preferred JCE provider, etc.
*
* In addition, there are two important properties (initially delivered as unset
* from the ESAPI download) named {@code Encryptor.MasterKey} and
* {@code Encryptor.MasterSalt} that must be set before using ESAPI encryption.
* There is a bash(1) shell script provided with the standard ESAPI distribution
* called 'setMasterKey.sh' that will assist you in setting these two properties. The
* script is in 'src/examples/scripts/setMasterKey.sh'.
*
* Possible future enhancements (depending on feedback) are discussed in
* section 4 of
*
* Design Goals in OWASP ESAPI Cryptography.
*
* @author Jeff Williams (jeff.williams .at. aspectsecurity.com) Aspect Security
* @since June 1, 2007
* @see User Guide for Symmetric Encryption in ESAPI 2.0
*/
public interface Encryptor {
/**
* Returns a string representation of the hash of the provided plaintext and
* salt. The salt helps to protect against a rainbow table attack by mixing
* in some extra data with the plaintext. Some good choices for a salt might
* be an account name or some other string that is known to the application
* but not to an attacker.
* See
* this article for more information about hashing as it pertains to password schemes.
*
* @param plaintext
* the plaintext String to encrypt
* @param salt
* the salt to add to the plaintext String before hashing
*
* @return
* the encrypted hash of 'plaintext' stored as a String
*
* @throws EncryptionException
* if the specified hash algorithm could not be found or another problem exists with
* the hashing of 'plaintext'
*/
String hash(String plaintext, String salt) throws EncryptionException;
/**
* Returns a string representation of the hash of the provided plaintext and
* salt. The salt helps to protect against a rainbow table attack by mixing
* in some extra data with the plaintext. Some good choices for a salt might
* be an account name or some other string that is known to the application
* but not to an attacker.
* See
* this article for more information about hashing as it pertains to password schemes.
*
* @param plaintext
* the plaintext String to encrypt
* @param salt
* the salt to add to the plaintext String before hashing
* @param iterations
* the number of times to iterate the hash
*
* @return
* the encrypted hash of 'plaintext' stored as a String
*
* @throws EncryptionException
* if the specified hash algorithm could not be found or another problem exists with
* the hashing of 'plaintext'
*/
String hash(String plaintext, String salt, int iterations) throws EncryptionException;
/**
* Encrypts the provided plaintext bytes using the cipher transformation
* specified by the property Encryptor.CipherTransformation
* and the master encryption key as specified by the property
* {@code Encryptor.MasterKey} as defined in the ESAPI.properties file.
*
*
* @param plaintext The {@code PlainText} to be encrypted.
* @return the {@code CipherText} object from which the raw ciphertext, the
* IV, the cipher transformation, and many other aspects about
* the encryption detail may be extracted.
* @throws EncryptionException Thrown if something should go wrong such as
* the JCE provider cannot be found, the cipher algorithm,
* cipher mode, or padding scheme not being supported, specifying
* an unsupported key size, specifying an IV of incorrect length,
* etc.
* @see #encrypt(SecretKey, PlainText)
* @since 2.0
*/
CipherText encrypt(PlainText plaintext) throws EncryptionException;
/**
* Encrypts the provided plaintext bytes using the cipher transformation
* specified by the property Encryptor.CipherTransformation
* as defined in the ESAPI.properties file and the
* specified secret key.
*
* This method is similar to {@link #encrypt(PlainText)} except that it
* permits a specific {@code SecretKey} to be used for encryption.
*
* @param key The {@code SecretKey} to use for encrypting the plaintext.
* @param plaintext The byte stream to be encrypted. Note if a Java
* {@code String} is to be encrypted, it should be converted
* using {@code "some string".getBytes("UTF-8")}.
* @return the {@code CipherText} object from which the raw ciphertext, the
* IV, the cipher transformation, and many other aspects about
* the encryption detail may be extracted.
* @throws EncryptionException Thrown if something should go wrong such as
* the JCE provider cannot be found, the cipher algorithm,
* cipher mode, or padding scheme not being supported, specifying
* an unsupported key size, specifying an IV of incorrect length,
* etc.
* @see #encrypt(PlainText)
* @since 2.0
*/
CipherText encrypt(SecretKey key, PlainText plaintext)
throws EncryptionException;
/**
* Decrypts the provided {@link CipherText} using the information from it
* and the master encryption key as specified by the property
* {@code Encryptor.MasterKey} as defined in the {@code ESAPI.properties}
* file.
*
* @param ciphertext The {@code CipherText} object to be decrypted.
* @return The {@code PlainText} object resulting from decrypting the specified
* ciphertext. Note that it it is desired to convert the returned
* plaintext byte array to a Java String is should be done using
* {@code new String(byte[], "UTF-8");} rather than simply using
* {@code new String(byte[]);} which uses native encoding and may
* not be portable across hardware and/or OS platforms.
* @throws EncryptionException Thrown if something should go wrong such as
* the JCE provider cannot be found, the cipher algorithm,
* cipher mode, or padding scheme not being supported, specifying
* an unsupported key size, or incorrect encryption key was
* specified or a {@code PaddingException} occurs.
* @see #decrypt(SecretKey, CipherText)
*/
PlainText decrypt(CipherText ciphertext) throws EncryptionException;
/**
* Decrypts the provided {@link CipherText} using the information from it
* and the specified secret key.
*
* This decrypt method is similar to {@link #decrypt(CipherText)} except that
* it allows decrypting with a secret key other than the master secret key.
*
* @param key The {@code SecretKey} to use for encrypting the plaintext.
* @param ciphertext The {@code CipherText} object to be decrypted.
* @return The {@code PlainText} object resulting from decrypting the specified
* ciphertext. Note that it it is desired to convert the returned
* plaintext byte array to a Java String is should be done using
* {@code new String(byte[], "UTF-8");} rather than simply using
* {@code new String(byte[]);} which uses native encoding and may
* not be portable across hardware and/or OS platforms.
* @throws EncryptionException Thrown if something should go wrong such as
* the JCE provider cannot be found, the cipher algorithm,
* cipher mode, or padding scheme not being supported, specifying
* an unsupported key size, or incorrect encryption key was
* specified or a {@code PaddingException} occurs.
* @see #decrypt(CipherText)
*/
PlainText decrypt(SecretKey key, CipherText ciphertext) throws EncryptionException;
/**
* Create a digital signature for the provided data and return it in a
* string.
*
* Limitations: A new public/private key pair used for ESAPI 2.0 digital
* signatures with this method and {@link #verifySignature(String, String)}
* are dynamically created when the default reference implementation class,
* {@link org.owasp.esapi.reference.crypto.JavaEncryptor} is first created.
* Because this key pair is not persisted nor is the public key shared,
* this method and the corresponding {@link #verifySignature(String, String)}
* can not be used with expected results across JVM instances. This limitation
* will be addressed in ESAPI 2.1.
*
*
* @param data
* the data to sign
*
* @return
* the digital signature stored as a String
*
* @throws EncryptionException
* if the specified signature algorithm cannot be found
*/
String sign(String data) throws EncryptionException;
/**
* Verifies a digital signature (created with the sign method) and returns
* the boolean result.
*
* Limitations: A new public/private key pair used for ESAPI 2.0 digital
* signatures with this method and {@link #sign(String)}
* are dynamically created when the default reference implementation class,
* {@link org.owasp.esapi.reference.crypto.JavaEncryptor} is first created.
* Because this key pair is not persisted nor is the public key shared,
* this method and the corresponding {@link #sign(String)}
* can not be used with expected results across JVM instances. This limitation
* will be addressed in ESAPI 2.1.
*
* @param signature
* the signature to verify against 'data'
* @param data
* the data to verify against 'signature'
*
* @return
* true, if the signature is verified, false otherwise
*/
boolean verifySignature(String signature, String data);
/**
* Creates a seal that binds a set of data and includes an expiration timestamp.
*
* @param data
* the data to seal
* @param timestamp
* the absolute expiration date of the data, expressed as seconds since the epoch
*
* @return
* the seal
*
* @throws IntegrityException
*/
String seal(String data, long timestamp) throws IntegrityException;
/**
* Unseals data (created with the seal method) and throws an exception
* describing any of the various problems that could exist with a seal, such
* as an invalid seal format, expired timestamp, or decryption error.
*
* @param seal
* the sealed data
*
* @return
* the original (unsealed) data
*
* @throws EncryptionException
* if the unsealed data cannot be retrieved for any reason
*/
String unseal( String seal ) throws EncryptionException;
/**
* Verifies a seal (created with the seal method) and throws an exception
* describing any of the various problems that could exist with a seal, such
* as an invalid seal format, expired timestamp, or data mismatch.
*
* @param seal
* the seal to verify
*
* @return
* true, if the seal is valid. False otherwise
*/
boolean verifySeal(String seal);
/**
* Gets an absolute timestamp representing an offset from the current time to be used by
* other functions in the library.
*
* @param offset
* the offset to add to the current time
*
* @return
* the absolute timestamp
*/
long getRelativeTimeStamp( long offset );
/**
* Gets a timestamp representing the current date and time to be used by
* other functions in the library.
*
* @return
* a timestamp representing the current time
*/
long getTimeStamp();
}