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import sun.security.provider.MoreDrbgParameters;

import java.security.DrbgParameters;

import java.security.NoSuchAlgorithmException;

import java.security.SecureRandom;

import java.security.SecureRandomParameters;

import java.security.Security;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.List;

import java.util.stream.Collectors;

import static java.security.DrbgParameters.Capability.*;

/**

 * @test

 * @bug 8051408

 * @modules java.base/sun.security.provider

 * @summary make sure DRBG alg can be defined and instantiated freely

 */

public class DRBGAlg {

    public static void main(String[] args) throws Exception {

        check(null, "Hash_DRBG", "SHA-256", "reseed_only", ",128");

        check("", "Hash_DRBG", "SHA-256", "reseed_only", ",128");

        check("sha-1", "Hash_DRBG", "SHA-1", "reseed_only", ",128");

        check("sha-256", "Hash_DRBG", "SHA-256", "reseed_only", ",128");

        check("SHA-3");

        check("hash_drbg", "Hash_DRBG", "SHA-256", "reseed_only", ",128");

        check("hmac_drbg", "HMAC_DRBG", "SHA-256", "reseed_only", ",128");

        check("ctr_drbg", "CTR_DRBG", "AES-", "reseed_only", ",128", "use_df");

        // trying all permutations

        checkPermutations(

                Collections.emptyList(),

                Arrays.asList("hash_drbg","sha-512","Pr_and_Reseed","192"),

                "Hash_DRBG", "SHA-512", "pr_and_reseed", ",192");

        check("Hash_DRBG,Hmac_DRBG");

        check("SHA-1,SHA-256");

        check("128,256");

        check("none,reseed_only");

        check("use_df,no_df");

        check("Hash_DRBG,,SHA-1");

        check(null, DrbgParameters.instantiation(112, PR_AND_RESEED, null),

                "Hash_DRBG", "SHA-256", "pr_and_reseed", ",112");

        check(null, DrbgParameters.instantiation(256, PR_AND_RESEED, null),

                "Hash_DRBG", "SHA-256", "pr_and_reseed", ",256");

        check(null, DrbgParameters.instantiation(384, PR_AND_RESEED, null));

        check("sha-1", DrbgParameters.instantiation(112, PR_AND_RESEED, null),

                "Hash_DRBG", "SHA-1", "pr_and_reseed", ",112");

        check("sha-1", DrbgParameters.instantiation(192, PR_AND_RESEED, null));

        check("hash_drbg,sha-512,Pr_and_Reseed,192",

                DrbgParameters.instantiation(112, NONE, null),

                "Hash_DRBG", "SHA-512", "reseed_only", ",112");

        check("hash_drbg,sha-512,Pr_and_Reseed,192",

                DrbgParameters.instantiation(-1, NONE, null),

                "Hash_DRBG", "SHA-512", "reseed_only", ",192");

        // getInstance params can be stronger than definition

        check("hash_drbg,sha-256,None,112",

                DrbgParameters.instantiation(192, PR_AND_RESEED, null),

                "Hash_DRBG", "SHA-256", "pr_and_reseed", ",192");

        check("hash_drbg,sha-1", new MoreDrbgParameters(

                    null, null, "sha-512", null, false,

                    DrbgParameters.instantiation(-1, NONE, null)),

                "Hash_DRBG", "SHA-512");

        check("hash_drbg,sha-1", new MoreDrbgParameters(

                    null, null, null, null, false,

                    DrbgParameters.instantiation(-1, NONE, null)),

                "Hash_DRBG", "SHA-1");

        check("hash_drbg", new MoreDrbgParameters(

                    null, "hmac_drbg", null, null, false,

                    DrbgParameters.instantiation(-1, NONE, null)),

                "HMAC_DRBG", "SHA-256");

        check("hash_drbg,sha-1", new MoreDrbgParameters(

                    null, null, "sha-3", null, false,

                    DrbgParameters.instantiation(-1, NONE, null)));

        check("hash_drbg,sha-1", new MoreDrbgParameters(

                    null, "Unknown_DRBG", null, null, false,

                    DrbgParameters.instantiation(-1, NONE, null)));

    }

    /**

     * Checks all permutatins of a config. This is a recursive method and

     * should be called with checkPermutations(empty,config,expected).

     *

     * @param current the current chosen aspects

     * @param remains the remaining

     * @param expected the expected effective config

     * @throws Exception when check fails

     */

    private static void checkPermutations(List<String> current,

            List<String> remains, String... expected) throws Exception {

        if (remains.isEmpty()) {

            check(current.stream().collect(Collectors.joining(",")), expected);

        } else {

            for (String r : remains) {

                List<String> newCurrent = new ArrayList<>(current);

                newCurrent.add(r);

                List<String> newRemains = new ArrayList<>(remains);

                newRemains.remove(r);

                checkPermutations(newCurrent, newRemains, expected);

            }

        }

    }

    /**

     * Checks DRBG definition for getInstance(alg, params).

     *

     * @param define DRBG

     * @param params getInstance request (null if none)

     * @param expected expected actual instantiate params, empty if should fail

     */

    static void check(String define, SecureRandomParameters params,

                      String... expected) throws Exception {

        System.out.println("Testing " + define + " with " + params + "...");

        String old = Security.getProperty("securerandom.drbg.config");

        if (define != null) {

            Security.setProperty("securerandom.drbg.config", define);

        }

        try {

            String result = params != null ?

                    SecureRandom.getInstance("DRBG", params).toString() :

                    SecureRandom.getInstance("DRBG").toString();

            System.out.println("Result " + result);

            if (expected.length == 0) {

                throw new Exception("should fail");

            }

            for (String s : expected) {

                if (!result.contains(s)) {

                    throw new Exception(result);

                }

            }

        } catch (NoSuchAlgorithmException e) {

            System.out.println("Result NSAE");

            if (expected.length > 0) {

                throw e;

            }

        } finally {

            Security.setProperty("securerandom.drbg.config", old);

        }

    }

    /**

     * Checks DRBG definition for getInstance(alg).

     *

     * @param define DRBG

     * @param expected expected actual instantiate params, empty if should fail

     */

    static void check(String define, String... expected) throws Exception {

        check(define, null, expected);

    }

}