feat: create KeyPairGenerator (#222)

* feat: implement KeyPairGenerator

* pr remarks

extensions/common/security/build.gradle.kts

@@ -0,0 +1,9 @@
+plugins {
+    `java-library`
+}
+
+dependencies {
+    implementation(libs.edc.spi.core)
+    implementation(libs.edc.util)
+    testImplementation(libs.edc.junit)
+}

extensions/common/security/src/main/java/org/eclipse/edc/identityhub/security/KeyPairGenerator.java

@@ -0,0 +1,114 @@
+/*
+ *  Copyright (c) 2024 Metaform Systems, Inc.
+ *
+ *  This program and the accompanying materials are made available under the
+ *  terms of the Apache License, Version 2.0 which is available at
+ *  https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Contributors:
+ *       Metaform Systems, Inc. - initial API and implementation
+ *
+ */
+
+package org.eclipse.edc.identityhub.security;
+
+import org.eclipse.edc.spi.result.Result;
+import org.eclipse.edc.util.string.StringUtils;
+import org.jetbrains.annotations.NotNull;
+
+import java.security.InvalidAlgorithmParameterException;
+import java.security.KeyPair;
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.security.spec.ECGenParameterSpec;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Convenience class, that takes an algorithm name and generator parameters and creates a {@link KeyPair}.
+ * Supports the following algorithms:
+ * <ul>
+ *     <li>RSA: parameters may contain a {@code length} entry, defaults to 2048</li>
+ *     <li>EC: parameters may contain a {@code curve} entry, defaults to {@code "secp256r1"}. Curves must be given as std names.</li>
+ *     <li>EdDSA: parameters may contain a {@code curve} entry, defaults to {@code "Ed25519"}. Only supports Ed25519 and X25519</li>
+ * </ul>
+ */
+public class KeyPairGenerator {
+
+    public static final String ALGORITHM_RSA = "RSA";
+    public static final String ALGORITHM_EC = "EC";
+    public static final String ALGORITHM_EDDSA = "EDDSA";
+    public static final String CURVE_ED25519 = "ed25519";
+    public static final String CURVE_X25519 = "x25519";
+    public static final List<String> SUPPORTED_ALGORITHMS = List.of(ALGORITHM_EC, ALGORITHM_RSA, ALGORITHM_EDDSA);
+    public static final List<String> SUPPORTED_EDDSA_CURVES = List.of(CURVE_ED25519, CURVE_X25519);
+    public static final int RSA_DEFAULT_LENGTH = 2048;
+    private static final String RSA_PARAM_LENGTH = "length";
+    private static final String EC_PARAM_CURVE = "curve";
+    private static final String EC_DEFAULT_CURVE = "secp256r1";
+
+    /**
+     * Generate a Java {@link KeyPair} from an algorithm identifier and generator parameters.
+     *
+     * @param algorithm  One of [EC, RSA, EdDSA]. If null, defaults to "EdDSA".
+     * @param parameters May contain specific paramters, such as "length" (RSA), or a "curve" (EC and EdDSA). May be empty, not null.
+     * @return A {@link KeyPair}, or a failure indicating what went wrong.
+     */
+    public static Result<KeyPair> generateKeyPair(String algorithm, Map<String, Object> parameters) {
+        if (StringUtils.isNullOrBlank(algorithm)) {
+            return generateEdDsa(CURVE_ED25519);
+        }
+        algorithm = algorithm.toUpperCase();
+        if (SUPPORTED_ALGORITHMS.contains(algorithm)) {
+            return switch (algorithm) {
+                case ALGORITHM_RSA -> generateRsa(Integer.parseInt(parameters.getOrDefault(RSA_PARAM_LENGTH, RSA_DEFAULT_LENGTH).toString()));
+                case ALGORITHM_EC -> generateEc(parameters.getOrDefault(EC_PARAM_CURVE, EC_DEFAULT_CURVE).toString());
+                case ALGORITHM_EDDSA -> generateEdDsa(parameters.getOrDefault(EC_PARAM_CURVE, CURVE_ED25519).toString());
+                default -> Result.failure(notSupportedError(algorithm));
+            };
+        }
+        return Result.failure(notSupportedError(algorithm));
+    }
+
+    private static Result<KeyPair> generateEc(String stdName) {
+        try {
+            var javaGenerator = java.security.KeyPairGenerator.getInstance(ALGORITHM_EC);
+            javaGenerator.initialize(new ECGenParameterSpec(stdName));
+            return Result.success(javaGenerator.generateKeyPair());
+        } catch (NoSuchAlgorithmException e) {
+            return Result.failure("Error generating EC keys: " + e);
+        } catch (InvalidAlgorithmParameterException e) {
+            return Result.failure("Error generating EC keys: %s is not a valid or supported EC curve std name. Details: %s".formatted(stdName, e.getMessage()));
+        }
+    }
+
+    private static Result<KeyPair> generateEdDsa(@NotNull String curve) {
+        curve = curve.toLowerCase();
+        if (SUPPORTED_EDDSA_CURVES.contains(curve)) {
+            try {
+                var javaGenerator = java.security.KeyPairGenerator.getInstance(curve);
+                return Result.success(javaGenerator.generateKeyPair());
+            } catch (NoSuchAlgorithmException e) {
+                return Result.failure("Error generating EdDSA/Ed25519 keys: " + e);
+            }
+        }
+        return Result.failure("Unsupported EdDSA Curve: %s. Currently only these are supported: %s.".formatted(curve, String.join(",", SUPPORTED_EDDSA_CURVES)));
+    }
+
+    private static Result<KeyPair> generateRsa(int length) {
+        try {
+            var javaGenerator = java.security.KeyPairGenerator.getInstance(ALGORITHM_RSA);
+            javaGenerator.initialize(length, new SecureRandom());
+            return Result.success(javaGenerator.generateKeyPair());
+        } catch (NoSuchAlgorithmException e) {
+            return Result.failure("Error generating RSA keys: " + e);
+        }
+    }
+
+    private static String notSupportedError(String algorithm) {
+        return "Could not generate key pair for algorithm '%s'. Currently only the following algorithms are supported: %s."
+                .formatted(algorithm, String.join(",", SUPPORTED_ALGORITHMS));
+    }
+}

extensions/common/security/src/test/java/org/eclipse/edc/identityhub/security/KeyPairGeneratorTest.java

@@ -0,0 +1,139 @@
+/*
+ *  Copyright (c) 2024 Metaform Systems, Inc.
+ *
+ *  This program and the accompanying materials are made available under the
+ *  terms of the Apache License, Version 2.0 which is available at
+ *  https://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Contributors:
+ *       Metaform Systems, Inc. - initial API and implementation
+ *
+ */
+
+package org.eclipse.edc.identityhub.security;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EmptySource;
+import org.junit.jupiter.params.provider.NullSource;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import java.security.AlgorithmParameters;
+import java.security.InvalidParameterException;
+import java.security.KeyPair;
+import java.security.NoSuchAlgorithmException;
+import java.security.interfaces.ECPrivateKey;
+import java.security.interfaces.RSAPrivateKey;
+import java.security.spec.ECGenParameterSpec;
+import java.security.spec.InvalidParameterSpecException;
+import java.util.Map;
+
+import static org.eclipse.edc.junit.assertions.AbstractResultAssert.assertThat;
+
+class KeyPairGeneratorTest {
+
+    @Test
+    void generateKeyPair_rsa_defaultLength() {
+        var rsaResult = KeyPairGenerator.generateKeyPair("RSA", Map.of());
+        assertThat(rsaResult).isSucceeded()
+                .extracting(KeyPair::getPrivate)
+                .isInstanceOf(RSAPrivateKey.class);
+
+        var key = (RSAPrivateKey) rsaResult.getContent().getPrivate();
+        Assertions.assertThat(key.getModulus().bitLength()).isEqualTo(2048); //could theoretically be less if key has 8 leading zeros, but we control the key generation.
+    }
+
+    @Test
+    void generateKeyPair_rsa_withLength() {
+        var rsaResult = KeyPairGenerator.generateKeyPair("RSA", Map.of("length", 4096));
+        assertThat(rsaResult).isSucceeded()
+                .extracting(KeyPair::getPrivate)
+                .isInstanceOf(RSAPrivateKey.class);
+
+        var key = (RSAPrivateKey) rsaResult.getContent().getPrivate();
+        Assertions.assertThat(key.getModulus().bitLength()).isEqualTo(4096); //could theoretically be less if key has 8 leading zeros, but we control the key generation.
+    }
+
+    @ParameterizedTest
+    @ValueSource(ints = {0, 1, -1, Integer.MAX_VALUE})
+    void generateKeyPair_rsa_withInvalidLength(int invalidLength) {
+        Assertions.assertThatThrownBy(() -> KeyPairGenerator.generateKeyPair("RSA", Map.of("length", invalidLength))).isInstanceOf(InvalidParameterException.class);
+    }
+
+    @Test
+    void generateKeyPair_ec_defaultCurve() throws InvalidParameterSpecException, NoSuchAlgorithmException {
+        var ecResult = KeyPairGenerator.generateKeyPair("EC", Map.of());
+        assertThat(ecResult).isSucceeded()
+                .extracting(KeyPair::getPrivate)
+                .isInstanceOf(ECPrivateKey.class);
+
+        var key = (ECPrivateKey) ecResult.getContent().getPrivate();
+        var algorithmParameters = AlgorithmParameters.getInstance("EC");
+        algorithmParameters.init(key.getParams());
+        var oid = algorithmParameters.getParameterSpec(ECGenParameterSpec.class).getName();
+        Assertions.assertThat(oid).isEqualTo("1.2.840.10045.3.1.7"); // no easy way to get the std name, only the OID
+    }
+
+    @ParameterizedTest()
+    @ValueSource(strings = {"secp256r1", "secp384r1", "secp521r1", "SECP256R1", "SecP521R1"})
+    void generateKeyPair_ec_withCurve(String curve) {
+        var ecResult = KeyPairGenerator.generateKeyPair("EC", Map.of("curve", curve));
+        assertThat(ecResult).isSucceeded()
+                .extracting(KeyPair::getPrivate)
+                .isInstanceOf(ECPrivateKey.class);
+    }
+
+    @ParameterizedTest()
+    @ValueSource(strings = {"secp256k1", "foobar"})
+    @EmptySource
+    void generateKeyPair_ec_withInvalidCurve(String curve) {
+        var ecResult = KeyPairGenerator.generateKeyPair("EC", Map.of("curve", curve));
+        assertThat(ecResult).isFailed()
+                .detail().contains("not a valid or supported EC curve std name");
+    }
+
+
+    @Test
+    void generateKeyPair_edDsa() {
+        var edDsaResult = KeyPairGenerator.generateKeyPair("EdDSA", Map.of());
+        assertThat(edDsaResult).isSucceeded()
+                .extracting(KeyPair::getPrivate)
+                .satisfies(k -> Assertions.assertThat(k.getClass().getName()).isEqualTo("sun.security.ec.ed.EdDSAPrivateKeyImpl")); // not available at compile time
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"Ed25519", "X25519", "ed25519", "x25519", "ED25519"})
+    void generateKeyPair_edDsa_withValidCurve(String curve) {
+        var edDsaResult = KeyPairGenerator.generateKeyPair("EdDSA", Map.of("curve", curve));
+        assertThat(edDsaResult).isSucceeded()
+                .extracting(KeyPair::getPrivate)
+                .satisfies(k -> Assertions.assertThat(k.getClass().getName()).startsWith("sun.security.ec.")); // not available at compile time
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"Ed448", "x448", "foobar"})
+    void generateKeyPair_edDsa_withInvalidCurve(String invalidCurve) {
+        var edDsaResult = KeyPairGenerator.generateKeyPair("EdDSA", Map.of("curve", invalidCurve));
+        assertThat(edDsaResult).isFailed()
+                .detail().contains("Unsupported EdDSA Curve: %s. Currently only these are supported: ed25519,x25519.".formatted(invalidCurve.toLowerCase()));
+    }
+
+    @ParameterizedTest
+    @NullSource
+    @EmptySource
+    void generateKeyPair_noAlgorithm(String nullOrEmpty) {
+        var result = KeyPairGenerator.generateKeyPair(nullOrEmpty, Map.of("foo", "bar"));
+        assertThat(result).isSucceeded()
+                .extracting(KeyPair::getPrivate)
+                .satisfies(k -> Assertions.assertThat(k.getClass().getName()).isEqualTo("sun.security.ec.ed.EdDSAPrivateKeyImpl")); // not available at compile time
+    }
+
+    @Test
+    void generateKeyPair_unknownAlgorithm() {
+        assertThat(KeyPairGenerator.generateKeyPair("foobar", Map.of())).isFailed()
+                .detail().matches("Could not generate key pair for algorithm '.*'. Currently only the following algorithms are supported: .*.");
+    }
+}

settings.gradle.kts

@@ -33,6 +33,7 @@ include(":core:identity-hub-credentials")
 include(":core:identity-hub-did")
 
 // extension modules
+include(":extensions:common:security")
 include(":extensions:store:sql:identity-hub-did-store-sql")
 include(":extensions:store:sql:identity-hub-credentials-store-sql")
 include(":extensions:did:local-did-publisher")