Add support for token resealing

Adds underlying support--and tooling--for resealing a token for
another recipient. This allows for delegating decryption to another
party without having to reveal the private key of the original
recipient (or having to send the raw underlying secret key over a
potentially insecure channel). Key ID can/should change as part of
this operation.

1 files changed, 59 insertions, 22 deletions

diff --git a/vespaclient-java/src/test/java/com/yahoo/vespa/security/tool/CryptoToolsTest.java b/vespaclient-java/src/test/java/com/yahoo/vespa/security/tool/CryptoToolsTest.java
index d4992e89802..42b747df678 100644
--- a/vespaclient-java/src/test/java/com/yahoo/vespa/security/tool/CryptoToolsTest.java
+++ b/vespaclient-java/src/test/java/com/yahoo/vespa/security/tool/CryptoToolsTest.java
@@ -1,6 +1,10 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.security.tool;
 
+import com.yahoo.security.KeyId;
+import com.yahoo.security.KeyUtils;
+import com.yahoo.security.SealedSharedKey;
+import com.yahoo.security.SharedKeyGenerator;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
@@ -16,6 +20,7 @@ import java.nio.file.attribute.PosixFilePermissions;
 import java.util.List;
 import java.util.Map;
 
+import static com.yahoo.security.ArrayUtils.hex;
 import static com.yahoo.security.ArrayUtils.toUtf8Bytes;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
@@ -27,7 +32,7 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
  */
 public class CryptoToolsTest {
 
-    private static record ProcessOutput(int exitCode, String stdOut, String stdErr) {}
+    private record ProcessOutput(int exitCode, String stdOut, String stdErr) {}
 
     private static final byte[] EMPTY_BYTES = new byte[0];
 
@@ -88,6 +93,11 @@ public class CryptoToolsTest {
     }
 
     @Test
+    void reseal_help_printed_if_help_option_given_to_subtool() throws IOException {
+        verifyStdoutMatchesFile(List.of("reseal", "--help"), "expected-reseal-help-output.txt");
+    }
+
+    @Test
     void missing_required_parameter_prints_error_message() throws IOException {
         // We don't test all possible input arguments to all tools, since it'd be too closely
         // bound to the order in which the implementation checks for argument presence.
@@ -174,6 +184,7 @@ public class CryptoToolsTest {
     private static final String TEST_TOKEN        = "OntP9gRVAjXeZIr4zkYqRJFcnA993v7ZEE7VbcNs1NcR3HdE7Mp" +
                                                     "wlwi3r3anF1kVa5fn7O1CyeHQpBWpdayUTKkrtyFepG6WJrZdE";
     private static final String TEST_TOKEN_KEY_ID = "my key ID";
+    private static final String TEST_TOKEN_SECRET = "1b33b4dcd6a94e5a4a1ee6d208197d01";
 
     @Test
     void encrypt_fails_with_error_message_if_no_input_file_is_given() throws IOException {
@@ -200,10 +211,10 @@ public class CryptoToolsTest {
         Files.writeString(privKeyFile, TEST_PRIV_KEY);
 
         verifyStderrEquals(List.of("decrypt",
-                                   "--output-file",                "foo",
-                                   "--recipient-private-key-file", absPathOf(privKeyFile),
-                                   "--token",                      TEST_TOKEN,
-                                   "--key-id",                     TEST_TOKEN_KEY_ID),
+                                   "--output-file",      "foo",
+                                   "--private-key-file", absPathOf(privKeyFile),
+                                   "--token",            TEST_TOKEN,
+                                   "--expected-key-id",  TEST_TOKEN_KEY_ID),
                 "Invalid command line arguments: Expected exactly 1 file argument to decrypt\n");
     }
 
@@ -214,10 +225,10 @@ public class CryptoToolsTest {
 
         verifyStderrEquals(List.of("decrypt",
                                    "no-such-file",
-                                   "--output-file",                "foo",
-                                   "--recipient-private-key-file", absPathOf(privKeyFile),
-                                   "--token",                      TEST_TOKEN,
-                                   "--key-id",                     TEST_TOKEN_KEY_ID),
+                                   "--output-file",      "foo",
+                                   "--private-key-file", absPathOf(privKeyFile),
+                                   "--token",            TEST_TOKEN,
+                                   "--expected-key-id",  TEST_TOKEN_KEY_ID),
                 "Invalid command line arguments: Input file 'no-such-file' does not exist\n");
     }
 
@@ -231,11 +242,11 @@ public class CryptoToolsTest {
 
         verifyStderrEquals(List.of("decrypt",
                                    absPathOf(inputFile),
-                                   "--output-file",                "foo",
-                                   "--recipient-private-key-file", absPathOf(privKeyFile),
-                                   "--token",                      TEST_TOKEN,
-                                   "--key-id",                     TEST_TOKEN_KEY_ID + "-wrong"),
-                "Invalid command line arguments: Key ID specified with --key-id does not " +
+                                   "--output-file",      "foo",
+                                   "--private-key-file", absPathOf(privKeyFile),
+                                   "--token",            TEST_TOKEN,
+                                   "--expected-key-id",  TEST_TOKEN_KEY_ID + "-wrong"),
+                "Invalid command line arguments: Key ID specified with --expected-key-id does not " +
                         "match key ID used when generating the supplied token\n");
     }
 
@@ -271,6 +282,32 @@ public class CryptoToolsTest {
     }
 
     @Test
+    void can_reseal_a_token_to_another_recipient() throws IOException {
+        String recipientPrivKeyStr = "GdgfBZzPDqrCVs5f1xaYJpXVGwJzgdTAF1NNWiDk16YZ";
+        String recipientPubKeyStr  = "AiUirFvFuLJ6s71QBNxiRcctB4umzM6r2roP4Rf8WDKM";
+
+        Path privKeyFile = pathInTemp("my-priv.txt");
+        Files.writeString(privKeyFile, TEST_PRIV_KEY);
+
+        var procOut = runMain(List.of(
+                "reseal",
+                TEST_TOKEN,
+                "--private-key-file",     absPathOf(privKeyFile),
+                "--recipient-public-key", recipientPubKeyStr,
+                "--expected-key-id",      TEST_TOKEN_KEY_ID,
+                "--key-id",               "some-recipient-key-id"));
+        assertEquals(0, procOut.exitCode());
+        assertEquals("", procOut.stdErr());
+        var resealedToken = procOut.stdOut().strip();
+
+        // Verify that the resealed token wraps the same secret as the original one
+        var recipientPrivKey = KeyUtils.fromBase58EncodedX25519PrivateKey(recipientPrivKeyStr);
+        var recvShared = SharedKeyGenerator.fromSealedKey(SealedSharedKey.fromTokenString(resealedToken), recipientPrivKey);
+        assertEquals(KeyId.ofString("some-recipient-key-id"), recvShared.sealedSharedKey().keyId());
+        assertEquals(TEST_TOKEN_SECRET, hex(recvShared.secretKey().getEncoded()));
+    }
+
+    @Test
     void can_end_to_end_keygen_encrypt_and_decrypt_via_files() throws IOException {
         String greatSecret = "Dogs can't look up";
 
@@ -310,10 +347,10 @@ public class CryptoToolsTest {
         procOut = runMain(List.of(
                 "decrypt",
                 absPathOf(encryptedPath),
-                "--output-file",                absPathOf(decryptedPath),
-                "--recipient-private-key-file", absPathOf(privPath),
-                "--key-id",                     "1234",
-                "--token",                      token
+                "--output-file",      absPathOf(decryptedPath),
+                "--private-key-file", absPathOf(privPath),
+                "--expected-key-id",  "1234",
+                "--token",            token
                 ));
         assertEquals(0, procOut.exitCode());
         assertEquals("", procOut.stdOut());
@@ -359,10 +396,10 @@ public class CryptoToolsTest {
         procOut = runMain(List.of(
                 "decrypt",
                 "-", // Decrypt stdin
-                "--output-file",                "-", // Plaintext to stdout
-                "--recipient-private-key-file", absPathOf(privPath),
-                "--key-id",                     "1234",
-                "--token",                      token
+                "--output-file",      "-", // Plaintext to stdout
+                "--private-key-file", absPathOf(privPath),
+                "--expected-key-id",  "1234",
+                "--token",            token
         ), Files.readAllBytes(encryptedPath));
 
         assertEquals(0, procOut.exitCode());