com.yahoo.security.token.TokenGenerator Maven / Gradle / Ivy
// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.security.token;
import com.yahoo.security.Base62;
import java.security.SecureRandom;
/**
*
* Generates new {@link Token} instances that encapsulate a given number of cryptographically
* secure random bytes and, with a sufficiently high number of bytes (>= 16), can be expected
* to be globally unique and computationally infeasible to guess or brute force.
*
* Tokens are returned in a printable and copy/paste-friendly form (Base62) with an optional
* prefix string.
*
* Example of token string generated with the prefix "itsa_me_mario_" and 32 random bytes:
*
*
* itsa_me_mario_nALfICMyrC4NFagwAkiOdGh80DPS1vSUPprGUKVPLya
*
*
* Tokens are considered secret information, and must be treated as such.
*
*/
public class TokenGenerator {
private static final SecureRandom CSPRNG = new SecureRandom();
public static Token generateToken(TokenDomain domain, String prefix, int nRandomBytes) {
if (nRandomBytes <= 0) {
throw new IllegalArgumentException("Token bytes must be a positive integer");
}
byte[] tokenRand = new byte[nRandomBytes];
CSPRNG.nextBytes(tokenRand);
return new Token(domain, "%s%s".formatted(prefix, Base62.codec().encode(tokenRand)));
}
}