Added option for extracting PublicKey

Hakky54 · Nov 5, 2023 · 653ce83 · 653ce83
1 parent fe4ca7c
commit 653ce83
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Showing 3 changed files with 54 additions and 2 deletions.
diff --git a/...ickstart-for-pem/src/main/java/nl/altindag/ssl/pem/exception/PublicKeyParseException.java b/...ickstart-for-pem/src/main/java/nl/altindag/ssl/pem/exception/PublicKeyParseException.java
@@ -20,6 +20,10 @@
  */
 public final class PublicKeyParseException extends PemParseException {
 
+    public PublicKeyParseException(Throwable cause) {
+        super(cause);
+    }
+
     public PublicKeyParseException(String message) {
         super(message);
     }

diff --git a/sslcontext-kickstart-for-pem/src/main/java/nl/altindag/ssl/pem/util/PemUtils.java b/sslcontext-kickstart-for-pem/src/main/java/nl/altindag/ssl/pem/util/PemUtils.java
@@ -22,6 +22,7 @@
 import nl.altindag.ssl.pem.exception.CertificateParseException;
 import nl.altindag.ssl.pem.exception.PemParseException;
 import nl.altindag.ssl.pem.exception.PrivateKeyParseException;
+import nl.altindag.ssl.pem.exception.PublicKeyParseException;
 import nl.altindag.ssl.util.KeyManagerUtils;
 import nl.altindag.ssl.util.TrustManagerUtils;
 import nl.altindag.ssl.util.internal.IOUtils;
@@ -35,19 +36,25 @@
 import org.bouncycastle.openssl.PEMKeyPair;
 import org.bouncycastle.openssl.PEMParser;
 import org.bouncycastle.openssl.X509TrustedCertificateBlock;
+import org.bouncycastle.openssl.jcajce.JcaMiscPEMGenerator;
 import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter;
 import org.bouncycastle.operator.OperatorCreationException;
 import org.bouncycastle.pkcs.PKCS8EncryptedPrivateKeyInfo;
 import org.bouncycastle.pkcs.PKCSException;
+import org.bouncycastle.util.io.pem.PemObject;
+import org.bouncycastle.util.io.pem.PemWriter;
 
 import javax.net.ssl.X509ExtendedKeyManager;
 import javax.net.ssl.X509ExtendedTrustManager;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.Reader;
 import java.io.StringReader;
+import java.io.StringWriter;
 import java.nio.file.Path;
+import java.security.KeyPair;
 import java.security.PrivateKey;
+import java.security.PublicKey;
 import java.security.Security;
 import java.security.cert.Certificate;
 import java.security.cert.CertificateException;
@@ -519,6 +526,31 @@ private static PrivateKey extractPrivateKey(PrivateKeyInfo privateKeyInfo) {
         }
     }
 
+    public static PublicKey extractPublicKey(PrivateKey privateKey) {
+        try(StringWriter writer = new StringWriter()) {
+            JcaMiscPEMGenerator pemGenerator = new JcaMiscPEMGenerator(privateKey, null);
+            PemObject pemObject = pemGenerator.generate();
+
+            PemWriter pemWriter = new PemWriter(writer);
+            pemWriter.writeObject(pemObject);
+            pemWriter.close();
+
+            try(StringReader stringReader = new StringReader(writer.toString());
+                PEMParser pemParser = new PEMParser(stringReader)) {
+                Object object = pemParser.readObject();
+                if (object instanceof PEMKeyPair) {
+                    PEMKeyPair pemKeyPair = (PEMKeyPair) object;
+                    KeyPair keyPair = getInstance().getKeyConverter().getKeyPair(pemKeyPair);
+                    return keyPair.getPublic();
+                } else {
+                    throw new PublicKeyParseException("Could not extract public key for the given private key.");
+                }
+            }
+        } catch (IOException exception) {
+            throw new PublicKeyParseException(exception);
+        }
+    }
+
     static PemUtils getInstance() {
         return INSTANCE;
     }

diff --git a/sslcontext-kickstart-for-pem/src/test/java/nl/altindag/ssl/pem/util/PemUtilsShould.java b/sslcontext-kickstart-for-pem/src/test/java/nl/altindag/ssl/pem/util/PemUtilsShould.java
@@ -20,6 +20,7 @@
 import nl.altindag.ssl.pem.exception.CertificateParseException;
 import nl.altindag.ssl.pem.exception.PemParseException;
 import nl.altindag.ssl.pem.exception.PrivateKeyParseException;
+import nl.altindag.ssl.pem.exception.PublicKeyParseException;
 import nl.altindag.ssl.util.KeyStoreUtils;
 import nl.altindag.ssl.util.internal.IOUtils;
 import org.bouncycastle.asn1.pkcs.PrivateKeyInfo;
@@ -49,6 +50,7 @@
 import java.security.KeyStore;
 import java.security.KeyStoreException;
 import java.security.PrivateKey;
+import java.security.PublicKey;
 import java.security.cert.CertificateException;
 import java.security.cert.X509Certificate;
 import java.util.Optional;
@@ -389,7 +391,6 @@ void throwGenericIOExceptionWhenInputStreamCanNotBeClosed() throws IOException {
                 .hasRootCauseMessage("KABOOM!!!");
     }
 
-
     @Test
     void loadUnencryptedPrivateKeyFromClassPath() {
         PrivateKey privateKey = PemUtils.loadPrivateKey(PEM_LOCATION + "unencrypted-identity.pem");
@@ -495,6 +496,15 @@ void parseUnencryptedPrivateKeyFromContent() {
         assertThat(privateKey).isNotNull();
     }
 
+    @Test
+    void extractPublicKeyFromPrivateKey() {
+        String identityContent = getResourceContent(PEM_LOCATION + "encrypted-identity.pem");
+        PrivateKey privateKey = PemUtils.parsePrivateKey(identityContent, DEFAULT_PASSWORD);
+        PublicKey publicKey = PemUtils.extractPublicKey(privateKey);
+
+        assertThat(publicKey).isNotNull();
+    }
+
     @Test
     void parseSingleTrustMaterialFromContentAsAsOneLiner() {
         String certificateContent = getResourceContent(PEM_LOCATION + "one-liner-stackexchange.pem");
@@ -575,7 +585,7 @@ void throwsIllegalArgumentExceptionWhenUnsupportedEncryptedRsaPrivateKeyIsProvid
     @Test
     void loadUnEncryptedRsaIdentityMaterialFromContentAsOneLiner() {
         String identityContent = getResourceContent(PEM_LOCATION + "one-liner-unencrypted-rsa-identity.pem");
-        X509ExtendedKeyManager keyManager = PemUtils.parseIdentityMaterial(identityContent, null);
+        X509ExtendedKeyManager keyManager = PemUtils.parseIdentityMaterial(identityContent);
 
         assertThat(keyManager).isNotNull();
     }
@@ -851,6 +861,12 @@ void throwGenericKeyStoreWhenSetKeyEntryThrowsKeyStoreException() throws KeyStor
         }
     }
 
+    @Test
+    void throwsPublicKeyParseExceptionForUnknownPrivateKeyWhenAttemptingToExtractPublicKey() {
+        assertThatThrownBy(() -> PemUtils.extractPublicKey(null))
+                .isInstanceOf(PublicKeyParseException.class);
+    }
+
     private String getResourceContent(String path) {
         try(InputStream resource = getResource(path);
             InputStreamReader inputStreamReader = new InputStreamReader(resource, StandardCharsets.UTF_8);