feat: Allow import of trust-only certificates

- These certificates do not have keys, because they are solely for trusting them.
- Also more rigorously verify arguments passed to OpenSSL

src/main/java/de/mlessmann/certassist/keystore/KeyStoreManager.java

@@ -16,6 +16,7 @@ import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
 import java.security.spec.PKCS8EncodedKeySpec;
 import java.util.Base64;
+import java.util.Objects;
 import java.util.concurrent.atomic.AtomicReference;
 import lombok.RequiredArgsConstructor;
 import lombok.SneakyThrows;
@@ -79,7 +80,10 @@ public class KeyStoreManager {
 
     public void loadPrivateKeyIntoStore(KeyStore keyStore, CertificateUsage cert) throws KeyStoreException {
         String passphrase = passwordProvider.getPasswordFor(cert.fingerprint());
-        var pKey = loadPrivateKey(cert.certificateKeyPath(), passphrase);
+        var pKey = loadPrivateKey(
+            Objects.requireNonNull(cert.certificateKeyPath(), "Certificate does not have a key to import."),
+            passphrase
+        );
         var certChain = loadCertificateChain(cert.fullchainPath());
         keyStore.setKeyEntry("KEY;%s".formatted(cert.fingerprint()), pKey, null, certChain);
     }

src/main/java/de/mlessmann/certassist/models/Certificate.java

@@ -50,7 +50,7 @@ public class Certificate {
     private byte[] cert = new byte[0];
 
     //@Lob - Cannot annotate column: https://github.com/xerial/sqlite-jdbc/issues/135
-    @Column(nullable = false)
+    @Column
     private byte[] privateKey = new byte[0];
 
     //@Lob - Cannot annotate column: https://github.com/xerial/sqlite-jdbc/issues/135

src/main/java/de/mlessmann/certassist/openssl/CertificateUsage.java

@@ -16,9 +16,11 @@ public interface CertificateUsage extends AutoCloseable {
 
     /**
      * Returns the path to the private key file (on disk, potentially temporary depending on the storage implementation).
-     * This file should also be encrypted.
+     * This file should also be encrypted as the file system is considered in-flight.
      * @see CertificatePasswordProvider
+     * @apiNote Return value can be null, when there is no private key (e.g. imported certificates for trust only)
      */
+    @Nullable
     Path certificateKeyPath();
 
     /**

src/main/java/de/mlessmann/certassist/openssl/OpenSSLService.java

@@ -1,6 +1,7 @@
 package de.mlessmann.certassist.openssl;
 
 import static de.mlessmann.certassist.Constants.CERTASSIST_TMP_PREFIX;
+import static java.util.Objects.requireNonNull;
 import static java.util.concurrent.TimeUnit.*;
 import static org.slf4j.LoggerFactory.getLogger;
 
@@ -33,6 +34,7 @@ import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.springframework.lang.NonNull;
+import org.springframework.lang.Nullable;
 import org.springframework.stereotype.Service;
 import org.springframework.util.CollectionUtils;
 import org.zeroturnaround.exec.ProcessExecutor;
@@ -105,6 +107,12 @@ public class OpenSSLService {
         }
     }
 
+    private static void requireNotBlank(@Nullable String str, @NonNull String failMessage) {
+        if (StringUtils.isBlank(str)) {
+            throw new IllegalArgumentException(failMessage);
+        }
+    }
+
     @NonNull
     public OpenSSLCertificateResult createCertificate(CertificateInfo request) throws CommandLineOperationException {
         Path tmpDir;
@@ -126,11 +134,16 @@ public class OpenSSLService {
         }
 
         try (var certAuthority = certificateProvider.requestCertificateUsage(request.getTrustingAuthority())) {
+            Path pKeyPath = requireNonNull(
+                certAuthority.certificateKeyPath(),
+                "Cannot sign a certificate with a CA for which the key is not available!"
+            );
+
             Path signingRequest = createSigningRequest(request, keyFile, tmpDir.resolve("child.csr"), keyPassphrase);
             Path signedCert = signCertificate(
                 request,
                 certAuthority.certificatePath(),
-                certAuthority.certificateKeyPath(),
+                pKeyPath,
                 passwordProvider.getPasswordFor(certAuthority.fingerprint()),
                 signingRequest
             );
@@ -153,11 +166,14 @@ public class OpenSSLService {
         }
     }
 
-    private Path createKeyfile(CertificateInfo request, Path outFile, String filePassword)
+    @NonNull
+    private Path createKeyfile(@NonNull CertificateInfo request, @NonNull Path outFile, @NonNull String keyPassphrase)
         throws CommandLineOperationException {
+        requireNotBlank(keyPassphrase, "A passphrase must be provided to generate private keys!");
+        requireNonNull(outFile, "Output file must be provided to generate keys!");
         Path keyFile = outFile.toAbsolutePath();
-        log.debug("Writing new certificate key to {}", keyFile);
 
+        log.debug("Writing new certificate key to {}", keyFile);
         StartedProcess keygenProc = null;
         try {
             keygenProc =
@@ -172,7 +188,7 @@ public class OpenSSLService {
                     OSSL_ARG_KEY_PW,
                     Integer.toString(request.getRequestedKeyLength())
                 )
-                .environment(OSSL_ENV_KEY_PW, filePassword)
+                .environment(OSSL_ENV_KEY_PW, keyPassphrase)
                 .redirectOutput(Slf4jStream.of(openSSLLogger).asDebug())
                 .redirectError(Slf4jStream.of(openSSLLogger).asError())
                 .start();
@@ -185,10 +201,18 @@ public class OpenSSLService {
         return keyFile;
     }
 
-    private Path createCertificate(CertificateInfo request, Path keyFile, Path outFile, String keyPassphrase)
+    @NonNull
-        throws CommandLineOperationException {
+    private Path createCertificate(
-        log.debug("Writing new certificate file {}", outFile);
+        @NonNull CertificateInfo request,
+        @NonNull Path keyFile,
+        Path outFile,
+        @NonNull String keyPassphrase
+    ) throws CommandLineOperationException {
+        requireNonNull(outFile, "Output file must be provided to generate certificates!");
+        requireNonNull(keyFile, "Private key file must be provided to generate certificates!");
+        requireNotBlank(keyPassphrase, "Private key passphrase must be provided to generate certificates.");
 
+        log.debug("Writing new certificate file {}", outFile);
         String certSubject = buildSubjectArg(request);
         StartedProcess certGenProc = null;
         try {
@@ -225,9 +249,17 @@ public class OpenSSLService {
         return outFile;
     }
 
-    private Path createSigningRequest(CertificateInfo request, Path keyFile, Path outFile, String certPassword)
+    @NonNull
-        throws CommandLineOperationException {
+    private Path createSigningRequest(
-        log.atDebug().log("Writing new certificate signing request file {}", outFile);
+        @NonNull CertificateInfo request,
+        @NonNull Path keyFile,
+        @NonNull Path outFile,
+        @NonNull String pkeyPassphrase
+    ) throws CommandLineOperationException {
+        requireNonNull(keyFile, "Private key must be provided to generate CSR!");
+        requireNonNull(outFile, "Output file must be provided to generate CSR!");
+        requireNotBlank(pkeyPassphrase, "Passphrase for private key must be provided to create CSR.");
+        log.debug("Writing new certificate signing request file {}", outFile);
 
         String certSubject = buildSubjectArg(request);
         StartedProcess certGenProc = null;
@@ -249,7 +281,7 @@ public class OpenSSLService {
                     "-subj",
                     certSubject
                 )
-                .environment(OSSL_ENV_KEY_PW, certPassword)
+                .environment(OSSL_ENV_KEY_PW, pkeyPassphrase)
                 .redirectOutput(Slf4jStream.of(openSSLLogger).asDebug())
                 .redirectError(Slf4jStream.of(openSSLLogger).asError())
                 .start();
@@ -270,10 +302,10 @@ public class OpenSSLService {
     public boolean verifyCertificate(@NonNull Path fullChainFile, @NonNull List<Path> trustedCAs)
         throws CommandLineOperationException {
         if (CollectionUtils.isEmpty(trustedCAs)) {
-            throw new IllegalArgumentException(
+            log.warn("No trusted CA provided for verification. Certificate is untrusted.");
-                "At least one trusted CA certificate must be provided to run the verification command."
+            return false;
-            );
         }
+        requireNonNull(fullChainFile, "Cannot verify certificate without fullChainFile");
 
         Path tmpDir = null;
         StartedProcess verifyCommand = null;
@@ -339,6 +371,8 @@ public class OpenSSLService {
      */
     public boolean verifyKeyPassphrase(@NonNull Path keyFile, @NonNull String passphrase)
         throws CommandLineOperationException {
+        requireNonNull(keyFile, "Key file must be provided to check encryption.");
+        requireNonNull(passphrase, "Must provide a passphrase to check encryption.");
         StartedProcess verifyCommand = null;
         try {
             verifyCommand =
@@ -365,16 +399,22 @@ public class OpenSSLService {
         }
     }
 
+    @NonNull
     private Path signCertificate(
         CertificateInfo request,
-        Path caCert,
+        @NonNull Path caCert,
-        Path caKey,
+        @NonNull Path caKey,
-        String caKeyPassphrase,
+        @NonNull String caKeyPassphrase,
-        Path csrFile
+        @NonNull Path csrFile
     ) throws CommandLineOperationException {
+        requireNonNull(caCert, "CA certificate must be provided to sign certs!");
+        requireNonNull(caKey, "CA private key must be provided to sign certs!");
+        requireNotBlank(caKeyPassphrase, "CA private key passphrase must be provided to sign certs!");
+        requireNonNull(csrFile, "CSR to be signed must be provided.");
+
         Path outFile = csrFile.resolveSibling(csrFile.getFileName().toString().replace(".csr", ".crt"));
-        log.debug("Writing new signed certificate file {}", outFile);
         Path extFile = csrFile.resolveSibling(csrFile.getFileName().toString().replace(".csr", ".ext"));
+        log.debug("Writing new signed certificate file {}", outFile);
 
         try {
             String extContent = CSR_EXT_TEMPLATE;
@@ -394,7 +434,7 @@ public class OpenSSLService {
                 extContent = extContent.replaceAll("\\[alt_names]\n?", "");
             }
 
-            log.debug("Writing extension file content: \n {}", extContent);
+            log.debug("Writing extension file {} with content: \n {}", extFile, extContent);
             Files.writeString(
                 extFile,
                 extContent,
@@ -449,7 +489,10 @@ public class OpenSSLService {
         return outFile;
     }
 
-    public String getCertificateFingerprint(Path certificate) throws CommandLineOperationException {
+    @NonNull
+    public String getCertificateFingerprint(@NonNull Path certificate) throws CommandLineOperationException {
+        requireNonNull(certificate, "Certificate must be provided to generate fingerprint.");
+
         StartedProcess fingerprintProc = null;
         try {
             fingerprintProc =
@@ -492,7 +535,10 @@ public class OpenSSLService {
         }
     }
 
+    @NonNull
     public CertificateInfo getCertificateInfo(Path path) throws CommandLineOperationException {
+        requireNonNull(path, "Certificate file must be provided to read the info.");
+
         StartedProcess infoProc = null;
         try {
             infoProc =
@@ -534,9 +580,12 @@ public class OpenSSLService {
             return getCertificateInfo(output.lines().toArray(String[]::new));
         } catch (IOException | ExecutionException | InterruptedException | TimeoutException e) {
             throw new RuntimeException(e);
+        } finally {
+            killIfActive(infoProc);
         }
     }
 
+    @NonNull
     private String resolveOpenSSL() throws CommandLineOperationException {
         try {
             String path = executableResolver.getOpenSSLPath();
@@ -621,7 +670,12 @@ public class OpenSSLService {
         };
     }
 
-    public String readDecryptedKey(Path keyFile, String passphrase) throws CommandLineOperationException {
+    @NonNull
+    public String readDecryptedKey(@NonNull Path keyFile, @NonNull String passphrase)
+        throws CommandLineOperationException {
+        requireNonNull(keyFile, "Key to be decrypted must be provided!");
+        requireNotBlank(passphrase, "Passphrase for private key must be provided to run decryption.");
+
         StartedProcess keyReadProc = null;
         try {
             keyReadProc =

src/main/java/de/mlessmann/certassist/service/CertificateCreationService.java

@@ -10,6 +10,8 @@ import java.nio.file.Path;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.apache.commons.lang3.StringUtils;
+import org.springframework.lang.NonNull;
+import org.springframework.lang.Nullable;
 import org.springframework.stereotype.Service;
 
 @Service
@@ -24,7 +26,10 @@ public class CertificateCreationService {
         final Certificate certificate = createEntityFromRequest(certificateInfo);
 
         try (OpenSSLCertificateResult certificateCreatorResult = openSSLService.createCertificate(certificateInfo);) {
-            certificate.setPrivateKey(Files.readAllBytes(certificateCreatorResult.certificateKeyPath()));
+            Path keyPath = certificateCreatorResult.certificateKeyPath();
+            if (keyPath != null) {
+                certificate.setPrivateKey(Files.readAllBytes(keyPath));
+            }
             certificate.setCert(Files.readAllBytes(certificateCreatorResult.certificatePath()));
         } catch (CommandLineOperationException | IOException e) {
             throw new IllegalStateException("Failed to create certificate!", e);
@@ -59,15 +64,22 @@ public class CertificateCreationService {
         return certificate;
     }
 
-    public Certificate importCertificate(Path certificate, Path keyFile, String passphrase) {
+    @NonNull
+    public Certificate importCertificate(
+        @NonNull Path certificate,
+        @Nullable Path keyFile,
+        @Nullable String keyPassphrase
+    ) {
         try {
             String fingerprint = openSSLService.getCertificateFingerprint(certificate);
             var generatedRequest = openSSLService.getCertificateInfo(certificate);
             Certificate entity = createEntityFromRequest(generatedRequest);
             entity.setCert(Files.readAllBytes(certificate));
-            entity.setPrivateKey(Files.readAllBytes(keyFile));
+            if (keyFile != null) {
-            if (StringUtils.isNotBlank(passphrase)) {
+                entity.setPrivateKey(Files.readAllBytes(keyFile));
-                passphraseService.storePassphrase("cert:" + fingerprint, passphrase);
+            }
+            if (StringUtils.isNotBlank(keyPassphrase)) {
+                passphraseService.storePassphrase("cert:" + fingerprint, keyPassphrase);
             }
             return certificateRepository.save(entity);
         } catch (CommandLineOperationException | IOException e) {

src/test/java/de/mlessmann/certassist/CertificateServiceTest.java

@@ -14,6 +14,8 @@ import org.springframework.boot.test.context.SpringBootTest;
 @SpringBootTest
 public class CertificateServiceTest {
 
+    public static final Path LETSENCRYPT_CERT_PATH = Path.of("src/test/resources/letsencrypt");
+
     @Autowired
     private CertificateCreationService certificateService;
 
@@ -49,4 +51,12 @@ public class CertificateServiceTest {
         assertThat(importedCert).isNotNull();
         assertThat(importedCert.getId()).isGreaterThan("0");
     }
+
+    @Test
+    void testCanImportTrustCertificate() {
+        Path cert = LETSENCRYPT_CERT_PATH.resolve("2024-11-isrgrootx1.pem");
+        var importedCert = certificateService.importCertificate(cert, null, null);
+        assertThat(importedCert).isNotNull();
+        assertThat(importedCert.getId()).isGreaterThan("0");
+    }
 }

src/test/resources/letsencrypt/2024-11-isrg-root-x2.pem

@@ -0,0 +1,14 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

src/test/resources/letsencrypt/2024-11-isrgrootx1.pem

@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----
+MIIFazCCA1OgAwIBAgIRAIIQz7DSQONZRGPgu2OCiwAwDQYJKoZIhvcNAQELBQAw
+TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh
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+ZXQgU2VjdXJpdHkgUmVzZWFyY2ggR3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBY
+MTCCAiIwDQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIBAK3oJHP0FDfzm54rVygc
+h77ct984kIxuPOZXoHj3dcKi/vVqbvYATyjb3miGbESTtrFj/RQSa78f0uoxmyF+
+0TM8ukj13Xnfs7j/EvEhmkvBioZxaUpmZmyPfjxwv60pIgbz5MDmgK7iS4+3mX6U
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+TkXWStAmzOVyyghqpZXjFaH3pO3JLF+l+/+sKAIuvtd7u+Nxe5AW0wdeRlN8NwdC
+jNPElpzVmbUq4JUagEiuTDkHzsxHpFKVK7q4+63SM1N95R1NbdWhscdCb+ZAJzVc
+oyi3B43njTOQ5yOf+1CceWxG1bQVs5ZufpsMljq4Ui0/1lvh+wjChP4kqKOJ2qxq
+4RgqsahDYVvTH9w7jXbyLeiNdd8XM2w9U/t7y0Ff/9yi0GE44Za4rF2LN9d11TPA
+mRGunUHBcnWEvgJBQl9nJEiU0Zsnvgc/ubhPgXRR4Xq37Z0j4r7g1SgEEzwxA57d
+emyPxgcYxn/eR44/KJ4EBs+lVDR3veyJm+kXQ99b21/+jh5Xos1AnX5iItreGCc=
+-----END CERTIFICATE-----