Fix SCryptPasswordEncoder javadoc

Issue gh-3702
This commit is contained in:
Rob Winch 2016-03-03 14:18:50 -06:00
parent fc75a679d9
commit 8fbc7e0d2c

View File

@ -24,14 +24,12 @@ import org.springframework.security.crypto.keygen.BytesKeyGenerator;
import org.springframework.security.crypto.keygen.KeyGenerators;
import org.springframework.security.crypto.password.PasswordEncoder;
/**
* <p>
* Implementation of PasswordEncoder that uses the SCrypt hashing function.
* Clients can optionally supply a cpu cost parameter, a memory cost parameter
* and a parallelization parameter.
*</p>
* </p>
*
* <p>
* A few <a href=
@ -45,9 +43,9 @@ import org.springframework.security.crypto.password.PasswordEncoder;
* unnecessary asymmetry between attacker and defender.</li>
* <li>Scrypt is based on Salsa20 which performs poorly in Java (on par with
* AES) but performs awesome (~4-5x faster) on SIMD capable platforms</li>
* <li>While there are some that would disagree, consider reading "<a href="
* http://blog.ircmaxell.com/2014/03/why-i-dont-recommend-scrypt.html
* ">Why I Don't Recommend Scrypt</a> (for password storage)"</li>
* <li>While there are some that would disagree, consider reading -
* <a href="http://blog.ircmaxell.com/2014/03/why-i-dont-recommend-scrypt.html">
* Why I Don't Recommend Scrypt</a> (for password storage)</li>
* </ul>
*
* @author Shazin Sadakath
@ -75,11 +73,24 @@ public class SCryptPasswordEncoder implements PasswordEncoder {
/**
* Creates a new instance
*
* @param cpuCost cpu cost of the algorithm (as defined in scrypt this is N). must be power of 2 greater than 1. Default is currently 16,348 or 2^14)
* @param memoryCost memory cost of the algorithm (as defined in scrypt this is r) Default is currently 8.
* @param parallelization the parallelization of the algorithm (as defined in scrypt this is p) Default is currently 1. Note that the implementation does not currently take advantage of parallelization.
* @param key length for the algorithm (as defined in scrypt this is dkLen). The default is currently 32.
* @param salt length (as defined in scrypt this is the length of S). The default is currently 64.
* @param cpuCost
* cpu cost of the algorithm (as defined in scrypt this is N).
* must be power of 2 greater than 1. Default is currently 16,348
* or 2^14)
* @param memoryCost
* memory cost of the algorithm (as defined in scrypt this is r)
* Default is currently 8.
* @param parallelization
* the parallelization of the algorithm (as defined in scrypt
* this is p) Default is currently 1. Note that the
* implementation does not currently take advantage of
* parallelization.
* @param keyLength
* key length for the algorithm (as defined in scrypt this is
* dkLen). The default is currently 32.
* @param saltLength
* salt length (as defined in scrypt this is the length of S).
* The default is currently 64.
*/
public SCryptPasswordEncoder(int cpuCost, int memoryCost, int parallelization, int keyLength, int saltLength) {
if (cpuCost <= 1) {
@ -94,13 +105,13 @@ public class SCryptPasswordEncoder implements PasswordEncoder {
int maxParallel = Integer.MAX_VALUE / (128 * memoryCost * 8);
if (parallelization < 1 || parallelization > maxParallel) {
throw new IllegalArgumentException("Parallelisation parameter p must be >= 1 and <= " + maxParallel
+ " (based on block size r of " + memoryCost + ")");
+ " (based on block size r of " + memoryCost + ")");
}
if (keyLength < 1 || keyLength > Integer.MAX_VALUE) {
throw new IllegalArgumentException("Key length must be >= 1 and <= "+Integer.MAX_VALUE);
throw new IllegalArgumentException("Key length must be >= 1 and <= " + Integer.MAX_VALUE);
}
if (saltLength < 1 || saltLength > Integer.MAX_VALUE) {
throw new IllegalArgumentException("Salt length must be >= 1 and <= "+Integer.MAX_VALUE);
throw new IllegalArgumentException("Salt length must be >= 1 and <= " + Integer.MAX_VALUE);
}
this.cpuCost = cpuCost;
@ -115,7 +126,7 @@ public class SCryptPasswordEncoder implements PasswordEncoder {
}
public boolean matches(CharSequence rawPassword, String encodedPassword) {
if(encodedPassword == null || encodedPassword.length() < keyLength) {
if (encodedPassword == null || encodedPassword.length() < keyLength) {
logger.warn("Empty encoded password");
return false;
}
@ -137,7 +148,8 @@ public class SCryptPasswordEncoder implements PasswordEncoder {
int memoryCost = (int) params >> 8 & 0xff;
int parallelization = (int) params & 0xff;
byte[] generated = SCrypt.generate(Utf8.encode(rawPassword), salt, cpuCost, memoryCost, parallelization, keyLength);
byte[] generated = SCrypt.generate(Utf8.encode(rawPassword), salt, cpuCost, memoryCost, parallelization,
keyLength);
if (derived.length != generated.length) {
return false;
@ -153,7 +165,8 @@ public class SCryptPasswordEncoder implements PasswordEncoder {
private String digest(CharSequence rawPassword, byte[] salt) {
byte[] derived = SCrypt.generate(Utf8.encode(rawPassword), salt, cpuCost, memoryCost, parallelization, 32);
String params = Long.toString(((int) (Math.log(cpuCost) / Math.log(2)) << 16L) | memoryCost << 8 | parallelization, 16);
String params = Long
.toString(((int) (Math.log(cpuCost) / Math.log(2)) << 16L) | memoryCost << 8 | parallelization, 16);
StringBuilder sb = new StringBuilder((salt.length + derived.length) * 2);
sb.append("$").append(params).append('$');