MikeFaith/aliro-project
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
3868678bf95c6773dc4897ec52aea0aae6af9fa9
aliro-project/applet/src/main/java/com/dangerousthings/aliro/AliroApplet.java
michael 3868678bf9 feat(applet): CoseVerifier RFC 9052 verify (M2A.2) 
Adds CoseVerifier.verifyCoseSign1 — single-purpose RFC 9052 COSE_Sign1
verifier for the Aliro IssuerAuth signature, used once at personalization
(M2A.3) to set CredentialStore.accessDocumentVerified.

Wire walk uses hardcoded offsets that assume the
aliro_harness.issuer.cose shape (matches RFC 9052 §3 but is not a generic
CBOR parser). TODO marker for M2B.3 to swap in StructuralCbor.elementSpan.

Extracts SECP256R1_{P,A,B,G,R} into Secp256r1Params so AliroApplet and
CoseVerifier share one copy. seed(KeyPair) handles full keypair seeding;
seedPublic(ECPublicKey) covers the verify-only case for the new verifier.

Test vector: deterministic-seeded P-256 key + literal payload, signed
once via the harness cose helpers and self-verified, hex-pasted into
CoseVerifierTest. Two cases (good signature; flipped payload byte).

Regression: 80 tests green; the 3 pre-existing GCM errors from the
jcardsim m2-volume swap (AliroCryptoTest#jcardsimSupportsAesGcm,
AliroGcmTest#{partialFinalBlock,roundTripAgainstJcardsimAEADCipher})
still error, unrelated to this change.
2026-06-17 16:04:05 -07:00

1210 lines
54 KiB
Java
Raw Blame History

package com.dangerousthings.aliro;
import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISO7816;
import javacard.framework.ISOException;
import javacard.framework.JCSystem;
import javacard.framework.Util;
import javacard.security.ECPrivateKey;
import javacard.security.ECPublicKey;
import javacard.security.KeyBuilder;
import javacard.security.KeyPair;
import javacard.security.MessageDigest;
import javacard.security.Signature;
/**
* Aliro v1.0 User Device applet.
*
* <p>Instantiated under {@link AliroAids#EXPEDITED} (and, once step-up is wired,
* also {@link AliroAids#STEP_UP}). A single class handles both phases; state
* is tracked internally.
*
* <p>Current scope:
* <ul>
* <li>SELECT returns a minimum-viable FCI template (spec &sect;10.2.1).
* <li>AUTH0 (standard phase) generates a fresh credential ephemeral
* P-256 keypair and returns the public key as tag 0x86 (spec
* &sect;8.3.3.2). Command input is not yet validated or stored.
* </ul>
*/
public class AliroApplet extends Applet {
private static final byte CLA_EXPEDITED = (byte) 0x80;
private static final byte INS_AUTH0 = (byte) 0x80;
private static final byte INS_AUTH1 = (byte) 0x81;
// Diagnostic INSes (CLA=0x80) for profiling AUTH1 sub-operations.
// DEV / PERFORMANCE-DEBUG ONLY. Set DIAGNOSTICS_ENABLED = false for any
// production CAP -- the JC converter dead-code-eliminates the disabled
// branches, so production binaries have zero attack surface from these.
//
// When enabled, each INS takes Lc=1 byte = iteration count N (1-255),
// runs the operation N times against hardcoded test vectors with sizes
// that match what AUTH1 actually does, then returns SW=9000. Output is
// written to the APDU buffer (per-APDU, transient -- never aliases the
// AUTH session scratch). The diagnostic keypair is allocated separately
// from the protocol's ephemeral keypair, so calling diag mid-transaction
// cannot clobber an in-flight AUTH0/AUTH1.
private static final boolean DIAGNOSTICS_ENABLED = true;
private static final byte INS_DIAG_HMAC = (byte) 0xD0;
private static final byte INS_DIAG_ECDH = (byte) 0xD1;
private static final byte INS_DIAG_ECDSA_SIGN = (byte) 0xD2;
private static final byte INS_DIAG_GCM = (byte) 0xD3;
// Session state layout (transient, CLEAR_ON_DESELECT + reset on SELECT).
private static final short OFF_READER_EPUBK = 0;
private static final short OFF_READER_GROUP_ID = 65;
private static final short OFF_READER_GROUP_SUB_ID = 81;
private static final short OFF_TRANSACTION_ID = 97;
private static final short OFF_COMMAND_PARAMETERS = 113;
private static final short OFF_AUTH_POLICY = 114;
private static final short OFF_AUTH1_CMD_PARAMS = 115;
private static final short SESSION_STATE_LEN = 116;
// Session flags (transient booleans).
private static final short FLAG_AUTH0_DONE = 0;
private static final short FLAGS_LEN = 1;
// AUTH0 command TLV tags, spec Table 8-4.
private static final byte TAG_COMMAND_PARAMETERS = (byte) 0x41;
private static final byte TAG_AUTHENTICATION_POLICY = (byte) 0x42;
private static final byte TAG_PROTOCOL_VERSION = (byte) 0x5C;
private static final byte TAG_READER_EPUBK = (byte) 0x87;
private static final byte TAG_TRANSACTION_ID = (byte) 0x4C;
private static final byte TAG_READER_IDENTIFIER = (byte) 0x4D;
// AUTH1 command TLV tags, spec Table 8-10.
private static final byte TAG_READER_SIGNATURE = (byte) 0x9E;
private static final byte TAG_READER_CERT = (byte) 0x90;
private static final short LEN_READER_SIGNATURE = 64;
private static final byte TAG_CREDENTIAL_EPUBK = (byte) 0x86;
// Bitmask of required AUTH1 tags.
private static final byte REQ_AUTH1_CMD_PARAMS = 0x01;
private static final byte REQ_AUTH1_READER_SIG = 0x02;
private static final byte REQ_ALL_AUTH1 = (byte) (REQ_AUTH1_CMD_PARAMS | REQ_AUTH1_READER_SIG);
// Expected lengths of the mandatory AUTH0 TLVs.
private static final short LEN_COMMAND_PARAMETERS = 1;
private static final short LEN_AUTHENTICATION_POLICY = 1;
private static final short LEN_PROTOCOL_VERSION = 2;
private static final short LEN_READER_EPUBK = 65;
private static final short LEN_TRANSACTION_ID = 16;
private static final short LEN_READER_IDENTIFIER = 32;
// Bitmask of required AUTH0 tags successfully parsed.
private static final byte REQ_CMD_PARAMS = 0x01;
private static final byte REQ_AUTH_POLICY = 0x02;
private static final byte REQ_PROTO_VER = 0x04;
private static final byte REQ_READER_EPUBK = 0x08;
private static final byte REQ_TXN_ID = 0x10;
private static final byte REQ_READER_ID = 0x20;
private static final byte REQ_ALL_AUTH0 = (byte) (REQ_CMD_PARAMS | REQ_AUTH_POLICY
| REQ_PROTO_VER | REQ_READER_EPUBK | REQ_TXN_ID | REQ_READER_ID);
/** ALIRO spec protocol version 0x0100 (major 1, minor 0). */
private static final short PROTOCOL_VERSION_1_0 = (short) 0x0100;
/** CSA application type, spec Table 10-4. */
private static final short APP_TYPE_CSA = (short) 0x0000;
/** Reusable ephemeral keypair — {@link KeyPair#genKeyPair()} refreshes it each AUTH0. */
private final KeyPair credentialEphemeralKeyPair;
/** Long-term Access Credential signing keypair. Curve params are set once at
* construction via {@code genKeyPair()}; the private scalar is overwritten
* per AUTH1 via {@link ECPrivateKey#setS} using bytes from {@link CredentialStore}. */
private final KeyPair credentialSigningKeyPair;
/** Holder for the provisioned reader long-term public key. Same underlying object across transactions; {@link ECPublicKey#setW} refreshes it per AUTH1. */
private final KeyPair readerPubKeyHolder;
/** Reusable ECDSA-SHA-256 verifier (reader signature) and signer (UD signature).
* Allocated lazily on first APDU — see {@link #ensureCryptoInitialized()}.
* Some real cards (notably J3R180) refuse {@code Cipher.getInstance(ALG_AES_GCM)}
* during {@code install()} even though it works at runtime; doing all
* crypto handle resolution lazily keeps install() trivial. */
private Signature ecdsaVerifier;
private Signature ecdsaSigner;
/** SHA-1 for key_slot = first 8 bytes of SHA-1(uncompressed credential_PubK). */
private MessageDigest sha1;
// Userland AES-256-GCM (built on AES-ECB-NOPAD + AES-256 key) is pulled
// from CryptoSingletons.getAliroGcm(). The target card (NXP J3R180) does
// not expose AEADCipher.ALG_AES_GCM despite advertising JC 3.0.5, so we
// implement GCM in userland. Sharing with StepUpApplet via the singleton
// saves ~370 B of transient/EEPROM footprint that a per-applet duplicate
// would otherwise pay. See encryptResponseGcm().
// Low-level crypto primitives (ECDH, HKDF, Kdh, expedited key derivation)
// are pulled from CryptoSingletons.getAliroCrypto() so both AliroApplet
// and StepUpApplet share one instance — saves ~352 B transient versus a
// per-applet duplicate. Local refs in deriveSessionKeys / processDiag.
/** Persistent (1B EEPROM) — set after {@link #ensureCryptoInitialized()} runs. */
private byte cryptoInitialized;
/** Transient buffers used during AUTH1 response construction. */
private final byte[] derivedKeys; // 160B: ExpeditedSKReader/Device, StepUpSK, BleSK, URSK
private final byte[] kdhBuf; // 32B
private final byte[] saltVolatile; // up to 200B
/** Transient session state. Cleared on deselect and on every SELECT. */
private final byte[] sessionState;
private final boolean[] sessionFlags;
/**
* Transient scratch buffer. Per-transaction layout:
* <pre>
* [ 0..128) Table 8-12 bytes (what gets signed)
* [128..200) DER-encoded reader signature for {@link Signature#verify}
* [200..265) uncompressed 65B reader pubkey for {@link ECPublicKey#setW}
* [265..329) raw 64B reader signature captured from AUTH1 input
* </pre>
*/
private final byte[] scratch;
private static final short SCRATCH_TABLE_812_OFF = 0;
private static final short SCRATCH_TABLE_812_LEN = 128;
private static final short SCRATCH_DER_SIG_OFF = 128;
private static final short SCRATCH_DER_SIG_CAPACITY = 72;
private static final short SCRATCH_READER_PUB_UNCOMP_OFF = 200;
private static final short SCRATCH_RAW_SIG_OFF = 265;
private static final short SCRATCH_LEN = 329;
private static final short DERIVED_KEYS_LEN = 160;
private static final short KDH_LEN = 32;
private static final short SALT_VOLATILE_CAPACITY = 200;
/** Offsets into {@link #derivedKeys} per spec §8.3.1.13. */
private static final short OFF_EXPEDITED_SK_READER = 0;
private static final short OFF_EXPEDITED_SK_DEVICE = 32;
private static final short OFF_STEP_UP_SK = 64;
/** Size of the 12-byte GCM IV (8B fixed prefix || 4B device_counter). */
private static final short GCM_IV_LEN = 12;
private static final short GCM_TAG_LEN = 16;
/** Aliro spec §8.3.1.13 salt_volatile constant strings. */
private static final byte[] SALT_VOLATILE_TAG = {
'V', 'o', 'l', 'a', 't', 'i', 'l', 'e', '*', '*', '*', '*'
};
// secp256r1 / NIST P-256 curve parameters live in {@link Secp256r1Params}
// — shared with {@link CoseVerifier}. J3R180 doesn't ship a default P-256
// parameter set on its EC keys, so seedSecp256r1() must run before any
// genKeyPair / setS / setW / Signature.init.
/** NFC interface byte, spec §8.3.1.13. */
private static final byte INTERFACE_BYTE_NFC = (byte) 0x5E;
/** Table 8-13 usage constant for UD signature (spec §8.3.3.4.3). */
private static final byte[] UD_SIGN_USAGE = {
(byte) 0x4E, (byte) 0x88, (byte) 0x7B, (byte) 0x4C
};
/** Proprietary 0xA5 TLV contributed by the NFC SELECT FCI (see {@link #sendExpeditedFci}). */
private static final byte[] PROPRIETARY_A5_TLV = {
(byte) 0xA5, (byte) 0x08,
(byte) 0x80, (byte) 0x02, (byte) 0x00, (byte) 0x00,
(byte) 0x5C, (byte) 0x02, (byte) 0x01, (byte) 0x00
};
/** Persistent — set to 1 once {@link #credentialSigningKeyPair} has had
* its P-256 curve parameters seeded by {@code genKeyPair()}. We defer
* this from the constructor to first AUTH1 because EC keypair generation
* during applet install fails on some real cards (notably J3R180 returned
* 0x6F00 for INSTALL[for install and make selectable]). genKeyPair runs
* exactly once over the lifetime of the applet. */
private byte signingKeyParamsInitialized;
private AliroApplet() {
// Keep install() trivial: only the JC-required transient buffers and
// stateless persistent KeyPair holders. Anything that calls
// Signature.getInstance / Cipher.getInstance / MessageDigest.getInstance /
// KeyBuilder.buildKey / new AliroCrypto() runs in ensureCryptoInitialized()
// on the first APDU. This avoids 0x6F00 from cards that resolve
// crypto algorithms lazily and refuse them during install().
credentialEphemeralKeyPair = new KeyPair(KeyPair.ALG_EC_FP, KeyBuilder.LENGTH_EC_FP_256);
credentialSigningKeyPair = new KeyPair(KeyPair.ALG_EC_FP, KeyBuilder.LENGTH_EC_FP_256);
readerPubKeyHolder = new KeyPair(KeyPair.ALG_EC_FP, KeyBuilder.LENGTH_EC_FP_256);
sessionState = JCSystem.makeTransientByteArray(SESSION_STATE_LEN, JCSystem.CLEAR_ON_DESELECT);
sessionFlags = JCSystem.makeTransientBooleanArray(FLAGS_LEN, JCSystem.CLEAR_ON_DESELECT);
scratch = JCSystem.makeTransientByteArray(SCRATCH_LEN, JCSystem.CLEAR_ON_DESELECT);
derivedKeys = JCSystem.makeTransientByteArray(DERIVED_KEYS_LEN, JCSystem.CLEAR_ON_DESELECT);
kdhBuf = JCSystem.makeTransientByteArray(KDH_LEN, JCSystem.CLEAR_ON_DESELECT);
saltVolatile = JCSystem.makeTransientByteArray(SALT_VOLATILE_CAPACITY, JCSystem.CLEAR_ON_DESELECT);
}
/** First-APDU lazy initialization for crypto handles. Runs exactly once
* over the applet's lifetime (gated by persistent {@link #cryptoInitialized}).
*
* <p>Everything here has proven loadable at {@code install()} time on
* J3R180 except the AES-GCM {@link Cipher#getInstance} call — J3R180
* advertises JC 3.0.5 but does not implement {@code ALG_AES_GCM}. We
* substitute {@link AliroGcm}, which builds GCM in userland on top of
* {@code ALG_AES_BLOCK_128_ECB_NOPAD}. The try/catches around
* {@link AliroGcm} construction throw 0x6FA8 so a future regression
* (e.g. AES-ECB-NOPAD or AES-256-key allocation disappearing from a new
* ROM revision) surfaces with a specific, greppable status word. */
private void ensureCryptoInitialized() {
if (cryptoInitialized != 0) return;
ecdsaVerifier = Signature.getInstance(Signature.ALG_ECDSA_SHA_256, false);
ecdsaSigner = Signature.getInstance(Signature.ALG_ECDSA_SHA_256, false);
sha1 = MessageDigest.getInstance(MessageDigest.ALG_SHA, false);
try {
// Force lazy alloc of the shared AliroGcm so any install-time
// failure (Cipher.getInstance / KeyBuilder.buildKey rejection)
// surfaces with the same greppable diagnostic SW as before.
CryptoSingletons.getAliroGcm();
} catch (ISOException e) { throw e; // preserve inner diagnostic SW
} catch (Throwable t) { ISOException.throwIt((short) 0x6FA8); }
try {
// Force lazy alloc of the shared AliroCrypto so the same install-
// time failure ladder applies if the constructor throws.
CryptoSingletons.getAliroCrypto();
} catch (ISOException e) { throw e; // preserve inner diagnostic SW (0x6FC1-C5)
} catch (Throwable t) { ISOException.throwIt((short) 0x6FA6); }
// Seed P-256 curve params on every keypair before any genKeyPair / setS /
// setW / Signature.init runs. J3R180 ships ECC keys with no default
// domain parameters; without this, ILLEGAL_VALUE comes back at first
// crypto use (we hit 0x6FE1 from genKeyPair before adding this).
try { seedSecp256r1(credentialEphemeralKeyPair); }
catch (Throwable t) { ISOException.throwIt((short) 0x6FB0); }
try { seedSecp256r1(credentialSigningKeyPair); }
catch (Throwable t) { ISOException.throwIt((short) 0x6FB1); }
try { seedSecp256r1(readerPubKeyHolder); }
catch (Throwable t) { ISOException.throwIt((short) 0x6FB2); }
cryptoInitialized = 1;
}
/** Loads the secp256r1 / NIST P-256 curve parameters into both halves of
* {@code kp}. Must run before any {@code genKeyPair}, {@code setS},
* {@code setW}, or {@code Signature.init} on cards (like J3R180) that
* don't preset domain parameters on freshly-allocated EC keys.
*
* <p>Thin wrapper over {@link Secp256r1Params#seed(KeyPair)} kept for
* call-site readability; the byte arrays live in the shared class. */
private static void seedSecp256r1(KeyPair kp) {
Secp256r1Params.seed(kp);
}
// --- Diagnostic test vectors -------------------------------------------
// Hardcoded inputs for the INS_DIAG_* operations. Sizes match what AUTH1
// exercises: 32B HMAC key (matches HKDF PRK), 64B HMAC message (matches
// SHA-256 block size), 12B AES-GCM IV, 137B plaintext (matches the actual
// Table 8-11 plaintext length when cmd_params bit 0 = 1).
private static final byte[] DIAG_KEY_32 = {
(byte) 0x00, (byte) 0x01, (byte) 0x02, (byte) 0x03,
(byte) 0x04, (byte) 0x05, (byte) 0x06, (byte) 0x07,
(byte) 0x08, (byte) 0x09, (byte) 0x0A, (byte) 0x0B,
(byte) 0x0C, (byte) 0x0D, (byte) 0x0E, (byte) 0x0F,
(byte) 0x10, (byte) 0x11, (byte) 0x12, (byte) 0x13,
(byte) 0x14, (byte) 0x15, (byte) 0x16, (byte) 0x17,
(byte) 0x18, (byte) 0x19, (byte) 0x1A, (byte) 0x1B,
(byte) 0x1C, (byte) 0x1D, (byte) 0x1E, (byte) 0x1F
};
private static final byte[] DIAG_MSG_64 = {
(byte) 0x20, (byte) 0x21, (byte) 0x22, (byte) 0x23, (byte) 0x24, (byte) 0x25, (byte) 0x26, (byte) 0x27,
(byte) 0x28, (byte) 0x29, (byte) 0x2A, (byte) 0x2B, (byte) 0x2C, (byte) 0x2D, (byte) 0x2E, (byte) 0x2F,
(byte) 0x30, (byte) 0x31, (byte) 0x32, (byte) 0x33, (byte) 0x34, (byte) 0x35, (byte) 0x36, (byte) 0x37,
(byte) 0x38, (byte) 0x39, (byte) 0x3A, (byte) 0x3B, (byte) 0x3C, (byte) 0x3D, (byte) 0x3E, (byte) 0x3F,
(byte) 0x40, (byte) 0x41, (byte) 0x42, (byte) 0x43, (byte) 0x44, (byte) 0x45, (byte) 0x46, (byte) 0x47,
(byte) 0x48, (byte) 0x49, (byte) 0x4A, (byte) 0x4B, (byte) 0x4C, (byte) 0x4D, (byte) 0x4E, (byte) 0x4F,
(byte) 0x50, (byte) 0x51, (byte) 0x52, (byte) 0x53, (byte) 0x54, (byte) 0x55, (byte) 0x56, (byte) 0x57,
(byte) 0x58, (byte) 0x59, (byte) 0x5A, (byte) 0x5B, (byte) 0x5C, (byte) 0x5D, (byte) 0x5E, (byte) 0x5F
};
private static final byte[] DIAG_IV_12 = {
(byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00,
(byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01,
(byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01
};
private static final short DIAG_GCM_PT_LEN = (short) 137;
/** Dedicated diagnostic keypair, allocated lazily on first INS_DIAG_* and
* used ONLY by the diag dispatcher. Kept separate from
* {@link #credentialEphemeralKeyPair} so a diagnostic call cannot
* clobber an in-flight AUTH0/AUTH1 transaction's ephemeral key. */
private javacard.security.KeyPair diagKeyPair;
/** Persistent flag: 1 once {@link #diagKeyPair} has been allocated and
* seeded with a random P-256 scalar via genKeyPair(). */
private byte diagInitialized;
private void ensureDiagInitialized() {
if (diagInitialized != 0) return;
diagKeyPair = new javacard.security.KeyPair(
javacard.security.KeyPair.ALG_EC_FP,
javacard.security.KeyBuilder.LENGTH_EC_FP_256);
seedSecp256r1(diagKeyPair);
diagKeyPair.genKeyPair();
diagInitialized = 1;
}
/** Dispatch for the four INS_DIAG_* profiling operations. Output is
* written into the APDU buffer (which is per-APDU and never aliases the
* AUTH session's {@link #scratch}), and all crypto runs against the
* dedicated {@link #diagKeyPair}, never the protocol's ephemeral key.
* Caller already gated on {@link #DIAGNOSTICS_ENABLED}. */
private void processDiag(APDU apdu, byte ins) {
ensureDiagInitialized();
short lc = apdu.setIncomingAndReceive();
byte[] buf = apdu.getBuffer();
if (lc != (short) 1) {
ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
}
short n = (short) (buf[apdu.getOffsetCdata()] & 0xFF);
if (n == (short) 0) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
// Diagnostic output lands in the APDU buffer past the Lc/data header
// (offset 16 leaves space for HMAC/ECDH 32B output, ECDSA DER sigs up
// to 72B, and AES-GCM 153B ciphertext+tag -- all fit in the standard
// 261-byte APDU buffer). Never reuses scratch -- AUTH session state
// stays intact.
final short DIAG_OUT_OFF = (short) 16;
// AES-GCM: encrypt in place at offset 16. pt/out overlap at the same
// offset is supported by AliroGcm.encrypt. Output is 137B ciphertext
// + 16B tag = 153B, ending at offset 169 -- well inside the 261B
// APDU buffer. Old code tried pt at offset 176 (16 + 160 reserved
// for the CT region) but that ran the 137B read off the end of the
// buffer at offset 313, throwing ArrayIndexOutOfBoundsException.
final short DIAG_GCM_PT_OFF = (short) 16;
final short DIAG_GCM_OUT_OFF = (short) 16;
switch (ins) {
case INS_DIAG_HMAC: {
AliroCrypto cryptoHmac = CryptoSingletons.getAliroCrypto();
for (short i = 0; i < n; i++) {
cryptoHmac.diagHmac(
DIAG_KEY_32, (short) 0, (short) DIAG_KEY_32.length,
DIAG_MSG_64, (short) 0, (short) DIAG_MSG_64.length,
buf, DIAG_OUT_OFF);
}
return;
}
case INS_DIAG_ECDH: {
javacard.security.ECPrivateKey priv =
(javacard.security.ECPrivateKey) diagKeyPair.getPrivate();
AliroCrypto cryptoEcdh = CryptoSingletons.getAliroCrypto();
for (short i = 0; i < n; i++) {
cryptoEcdh.computeEcdhSharedX(priv,
Secp256r1Params.SECP256R1_G, (short) 0,
buf, DIAG_OUT_OFF);
}
return;
}
case INS_DIAG_ECDSA_SIGN: {
// Sign with the DEDICATED diag keypair, never the protocol's
// credential or ephemeral keys. The signed message is also a
// fixed test vector, so this cannot be coerced into signing
// attacker-chosen data.
ecdsaSigner.init(diagKeyPair.getPrivate(),
Signature.MODE_SIGN);
for (short i = 0; i < n; i++) {
ecdsaSigner.sign(
DIAG_MSG_64, (short) 0, (short) DIAG_MSG_64.length,
buf, DIAG_OUT_OFF);
}
return;
}
case INS_DIAG_GCM: {
// Plaintext: 137 bytes anywhere in buf past the output region.
// Contents don't affect timing.
AliroGcm gcm = CryptoSingletons.getAliroGcm();
for (short i = 0; i < n; i++) {
gcm.encrypt(
DIAG_KEY_32, (short) 0,
DIAG_IV_12, (short) 0,
buf, DIAG_GCM_PT_OFF, DIAG_GCM_PT_LEN,
buf, DIAG_GCM_OUT_OFF);
}
return;
}
default:
ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
}
}
@Override
public boolean select() {
resetSession();
return true;
}
private void resetSession() {
Util.arrayFillNonAtomic(sessionState, (short) 0, SESSION_STATE_LEN, (byte) 0);
sessionFlags[FLAG_AUTH0_DONE] = false;
// A fresh expedited transaction invalidates any prior step-up arming.
SessionContext.disarmStepUp();
}
public static void install(byte[] bArray, short bOffset, byte bLength) {
AliroApplet applet = new AliroApplet();
if (bArray == null || bLength == 0) {
applet.register();
} else {
applet.register(bArray, (short) (bOffset + 1), bArray[bOffset]);
}
}
@Override
public void process(APDU apdu) {
if (selectingApplet()) {
sendExpeditedFci(apdu);
return;
}
// First non-SELECT APDU: resolve all crypto handles. One-time cost.
ensureCryptoInitialized();
byte[] buf = apdu.getBuffer();
byte cla = buf[ISO7816.OFFSET_CLA];
byte ins = buf[ISO7816.OFFSET_INS];
if (cla != CLA_EXPEDITED) {
ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED);
}
switch (ins) {
case INS_AUTH0:
processAuth0(apdu);
return;
case INS_AUTH1:
processAuth1(apdu);
return;
case INS_DIAG_HMAC:
case INS_DIAG_ECDH:
case INS_DIAG_ECDSA_SIGN:
case INS_DIAG_GCM:
// Compile-time gate: with DIAGNOSTICS_ENABLED=false the JC
// converter dead-code-eliminates the processDiag call, so a
// production CAP rejects these INSes the same way it rejects
// any other unsupported INS -- zero residual surface.
if (DIAGNOSTICS_ENABLED) {
processDiag(apdu, ins);
return;
}
ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
return;
default:
ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
}
}
/**
* Handles AUTH1 (spec &sect;8.3.3.4). Verifies the reader signature over
* Table 8-12, derives the Aliro session keys (§8.3.1.13), signs Table
* 8-13 with credential_PrivK, builds the Table 8-11 plaintext
* (key_slot or credential_PubK per command_parameters bit 0, UD sig,
* signaling_bitmap), and AES-256-GCM encrypts it with ExpeditedSKDevice.
* Response = encrypted_payload || authentication_tag.
*/
private void processAuth1(APDU apdu) {
if (!sessionFlags[FLAG_AUTH0_DONE]) {
ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED);
}
// One-shot: a single AUTH1 consumes the AUTH0 state. Clearing here —
// before any crypto — means even a mid-pipeline exception leaves the
// state consumed, so a replay cannot reuse the session keys (and
// critically cannot reuse device_counter=1, which would produce IV
// collisions in AES-GCM). A fresh AUTH0 is required to try again.
sessionFlags[FLAG_AUTH0_DONE] = false;
CredentialStore store = CredentialStore.get();
if (!store.hasReaderPubKey()
|| !store.hasCredentialPrivKey()
|| !store.hasCredentialPubKey()) {
ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED);
}
short lc = apdu.setIncomingAndReceive();
byte[] buf = apdu.getBuffer();
short dataOff = apdu.getOffsetCdata();
validateAuth1Data(buf, dataOff, lc);
verifyReaderSignature(store);
deriveSessionKeys(store);
loadCredentialSigningKey(store);
short udSigLen = signTable813AndGetRawSig(
scratch, SCRATCH_TABLE_812_OFF,
scratch, SCRATCH_DER_SIG_OFF,
scratch, SCRATCH_RAW_SIG_OFF);
short ptLen = buildTable811Plaintext(
sessionState[OFF_AUTH1_CMD_PARAMS], store,
scratch, SCRATCH_RAW_SIG_OFF, udSigLen,
buf, (short) 0);
short respLen = encryptResponseGcm(
buf, (short) 0, ptLen,
buf, (short) 0);
// AUTH1 succeeded; hand off StepUpSK (derived_keys[64..96]) to the
// cross-applet context so StepUpApplet can pick up the step-up flow.
SessionContext.armStepUp(derivedKeys, OFF_STEP_UP_SK);
apdu.setOutgoingAndSend((short) 0, respLen);
}
/**
* Reconstructs Table 8-12, loads the provisioned reader public key, and
* verifies the captured raw reader signature against the table. Throws
* SW_WRONG_DATA on any failure.
*/
private void verifyReaderSignature(CredentialStore store) {
short tblLen = buildTable812(scratch, SCRATCH_TABLE_812_OFF);
scratch[SCRATCH_READER_PUB_UNCOMP_OFF] = (byte) 0x04;
store.copyReaderPubKey(scratch, (short) (SCRATCH_READER_PUB_UNCOMP_OFF + 1));
ECPublicKey readerPub = (ECPublicKey) readerPubKeyHolder.getPublic();
readerPub.setW(scratch, SCRATCH_READER_PUB_UNCOMP_OFF, (short) 65);
short derLen = rawSigToDer(
scratch, SCRATCH_RAW_SIG_OFF,
scratch, SCRATCH_DER_SIG_OFF);
ecdsaVerifier.init(readerPub, Signature.MODE_VERIFY);
boolean ok = ecdsaVerifier.verify(
scratch, SCRATCH_TABLE_812_OFF, tblLen,
scratch, SCRATCH_DER_SIG_OFF, derLen);
if (!ok) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
}
/**
* Derives Kdh and {@code derived_keys_volatile} per spec §8.3.1.13 for
* the expedited-standard flow. The 32-byte {@code ExpeditedSKDevice}
* lands at {@code derivedKeys[OFF_EXPEDITED_SK_DEVICE..+32)}, ready to
* be passed into {@link AliroGcm#encrypt} as the AES key.
*/
private void deriveSessionKeys(CredentialStore store) {
short saltLen = buildSaltVolatile(store, saltVolatile, (short) 0);
short infoLen = buildInfo(scratch, SCRATCH_READER_PUB_UNCOMP_OFF);
AliroCrypto crypto = CryptoSingletons.getAliroCrypto();
crypto.deriveKdh(
(ECPrivateKey) credentialEphemeralKeyPair.getPrivate(),
sessionState, OFF_READER_EPUBK,
sessionState, OFF_TRANSACTION_ID, (short) 16,
kdhBuf, (short) 0);
crypto.deriveExpeditedStandardKeys(
kdhBuf, (short) 0,
saltVolatile, (short) 0, saltLen,
scratch, SCRATCH_READER_PUB_UNCOMP_OFF, infoLen,
derivedKeys, (short) 0);
}
/**
* Builds salt_volatile per spec §8.3.1.13 into {@code out} starting at
* {@code outOff}. Returns the total length written.
*
* <pre>
* x(reader_group_id_key) 32B (from CredentialStore)
* "Volatile****" 12B
* reader_identifier 32B (group_id || group_sub_id from AUTH0)
* interface_byte 1B (0x5E for NFC)
* 0x5C 0x02 2B (literal per spec)
* protocol_version 2B (0x01 0x00)
* x(reader_ephem_pub_key) 32B
* transaction_identifier 16B
* flag 2B (auth0 cmd_params || authentication_policy)
* proprietary_A5_TLV 10B (from SELECT FCI)
* </pre>
*
* <p>Spec §8.3.1.13 salt_volatile ends at the 0xA5 proprietary TLV. We
* previously appended x(access_credential_pub_key) here too -- that was
* an misread of the spec text (it belongs in {@code info}, not
* salt_volatile, and {@code info} uses the EPHEMERAL credential key, not
* the long-term one). The misread was symmetric between this applet and
* our PC/SC reader, so AUTH1 succeeded against our own host-side reader
* but failed against ST's X-CUBE-ALIRO with
* {@code ACWG_Error_Crypto_EncryptDecrypt}. Removed 2026-06-11.
*/
private short buildSaltVolatile(CredentialStore store, byte[] out, short outOff) {
short p = outOff;
// x(reader_group_identifier_key) — first 32 bytes of the 64B reader_PubK
store.copyReaderPubKeyX(out, p);
p += 32;
Util.arrayCopyNonAtomic(SALT_VOLATILE_TAG, (short) 0, out, p, (short) SALT_VOLATILE_TAG.length);
p += SALT_VOLATILE_TAG.length;
Util.arrayCopyNonAtomic(sessionState, OFF_READER_GROUP_ID, out, p, (short) 16);
p += 16;
Util.arrayCopyNonAtomic(sessionState, OFF_READER_GROUP_SUB_ID, out, p, (short) 16);
p += 16;
out[p++] = INTERFACE_BYTE_NFC;
out[p++] = (byte) 0x5C;
out[p++] = (byte) 0x02;
out[p++] = (byte) ((PROTOCOL_VERSION_1_0 >> 8) & 0xFF);
out[p++] = (byte) (PROTOCOL_VERSION_1_0 & 0xFF);
// reader_ephem_pub_key.x — sessionState holds full uncompressed (0x04 || x || y) at OFF_READER_EPUBK
Util.arrayCopyNonAtomic(sessionState, (short) (OFF_READER_EPUBK + 1), out, p, (short) 32);
p += 32;
Util.arrayCopyNonAtomic(sessionState, OFF_TRANSACTION_ID, out, p, (short) 16);
p += 16;
// flag = command_parameters || authentication_policy (1 byte each).
// command_parameters comes from the AUTH1 command -- "from the command
// data field" in §8.3.1.13 refers to the AUTH1 command being processed
// when keys are derived (the AUTH0 cmd_params still gets used for the
// EXPEDITED-FAST path's salt_persistent per §8.3.1.12, but for the
// EXPEDITED-STANDARD §8.3.1.13 path AUTH1 is the active request).
// authentication_policy only exists in AUTH0, so it's pulled from
// the AUTH0 state we saved earlier.
// Empirical confirmation: with AUTH0's cmd_params the X-CUBE-ALIRO
// vendor library failed AES-GCM tag verify on AUTH1 response with
// ACWG_Error_Crypto_EncryptDecrypt; AUTH1's cmd_params unblocks it.
out[p++] = sessionState[OFF_AUTH1_CMD_PARAMS];
out[p++] = sessionState[OFF_AUTH_POLICY];
Util.arrayCopyNonAtomic(PROPRIETARY_A5_TLV, (short) 0, out, p, (short) PROPRIETARY_A5_TLV.length);
p += PROPRIETARY_A5_TLV.length;
return (short) (p - outOff);
}
/**
* Builds {@code info} per §8.3.1.13: x(credential_ephemeral_public_key).
* In v1 we emit no AUTH0 vendor extensions and accept none, so info
* degenerates to the 32-byte x-coordinate of the ephemeral pubkey.
*/
private short buildInfo(byte[] out, short outOff) {
ECPublicKey ephemPub = (ECPublicKey) credentialEphemeralKeyPair.getPublic();
// Temp: first 65B of scratch — free at this point (phase 1 is done
// and phase 3 hasn't started).
short n = ephemPub.getW(scratch, (short) 0);
if (n != 65 || scratch[0] != 0x04) {
ISOException.throwIt(ISO7816.SW_UNKNOWN); // should be unreachable on P-256
}
Util.arrayCopyNonAtomic(scratch, (short) 1, out, outOff, (short) 32);
return (short) 32;
}
/** Overwrites {@link #credentialSigningKeyPair}'s private scalar with credential_PrivK.
* On first call, also seeds the keypair's P-256 curve parameters via genKeyPair()
* (the random scalar it produces is immediately discarded by setS below). */
private void loadCredentialSigningKey(CredentialStore store) {
if (signingKeyParamsInitialized == 0) {
credentialSigningKeyPair.genKeyPair();
signingKeyParamsInitialized = 1;
}
short off = SCRATCH_DER_SIG_OFF; // borrow scratch region; reader sig is no longer needed here
store.copyCredentialPrivKey(scratch, off);
((ECPrivateKey) credentialSigningKeyPair.getPrivate()).setS(
scratch, off, CredentialStore.CRED_PRIV_KEY_LEN);
}
/**
* Builds Table 8-13 into {@code t813Buf[t813Off..]}, signs it with
* {@code credential_PrivK}, and writes the raw 64-byte r||s signature to
* {@code rawSigBuf[rawSigOff..]}. Returns the raw sig length (always 64).
* The DER work buffer is only used internally.
*/
private short signTable813AndGetRawSig(
byte[] t813Buf, short t813Off,
byte[] derSigBuf, short derSigOff,
byte[] rawSigBuf, short rawSigOff) {
short t813Len = buildTable813(t813Buf, t813Off);
ecdsaSigner.init(credentialSigningKeyPair.getPrivate(), Signature.MODE_SIGN);
short derLen = ecdsaSigner.sign(t813Buf, t813Off, t813Len, derSigBuf, derSigOff);
derSigToRaw(derSigBuf, derSigOff, derLen, rawSigBuf, rawSigOff);
return (short) 64;
}
/**
* Builds Table 8-13 (UD-side authentication data, spec §8.3.3.4.3) into
* {@code dst[dstOff..]}. Identical to Table 8-12 except the 4-byte
* usage constant (0x4E887B4C instead of 0x415D9569).
*/
private short buildTable813(byte[] dst, short dstOff) {
short p = dstOff;
dst[p++] = (byte) 0x4D;
dst[p++] = (byte) 0x20;
Util.arrayCopyNonAtomic(sessionState, OFF_READER_GROUP_ID, dst, p, (short) 32);
p += 32;
ECPublicKey credPub = (ECPublicKey) credentialEphemeralKeyPair.getPublic();
credPub.getW(scratch, SCRATCH_READER_PUB_UNCOMP_OFF);
dst[p++] = (byte) 0x86;
dst[p++] = (byte) 0x20;
Util.arrayCopyNonAtomic(scratch, (short) (SCRATCH_READER_PUB_UNCOMP_OFF + 1), dst, p, (short) 32);
p += 32;
dst[p++] = (byte) 0x87;
dst[p++] = (byte) 0x20;
Util.arrayCopyNonAtomic(sessionState, (short) (OFF_READER_EPUBK + 1), dst, p, (short) 32);
p += 32;
dst[p++] = (byte) 0x4C;
dst[p++] = (byte) 0x10;
Util.arrayCopyNonAtomic(sessionState, OFF_TRANSACTION_ID, dst, p, (short) 16);
p += 16;
dst[p++] = (byte) 0x93;
dst[p++] = (byte) 0x04;
Util.arrayCopyNonAtomic(UD_SIGN_USAGE, (short) 0, dst, p, (short) UD_SIGN_USAGE.length);
p += UD_SIGN_USAGE.length;
return (short) (p - dstOff);
}
/**
* Converts a DER-encoded ECDSA P-256 signature into raw r||s (32+32)
* form. Strips the leading 0x00 that DER inserts when the high bit of
* r or s is set, and left-zero-pads shorter integers to 32 bytes.
*/
private static void derSigToRaw(
byte[] der, short derOff, short derLen,
byte[] raw, short rawOff) {
Util.arrayFillNonAtomic(raw, rawOff, (short) 64, (byte) 0);
short p = (short) (derOff + 2); // skip SEQUENCE tag + short-form length
if (der[p++] != 0x02) ISOException.throwIt(ISO7816.SW_UNKNOWN);
short rDerLen = (short) (der[p++] & 0xFF);
short rValStart = p;
short rValLen = rDerLen;
if (rValLen > 32 && der[rValStart] == 0x00) { rValStart++; rValLen--; }
Util.arrayCopyNonAtomic(der, rValStart, raw, (short) (rawOff + 32 - rValLen), rValLen);
p = (short) (p + rDerLen);
if (der[p++] != 0x02) ISOException.throwIt(ISO7816.SW_UNKNOWN);
short sDerLen = (short) (der[p++] & 0xFF);
short sValStart = p;
short sValLen = sDerLen;
if (sValLen > 32 && der[sValStart] == 0x00) { sValStart++; sValLen--; }
Util.arrayCopyNonAtomic(der, sValStart, raw, (short) (rawOff + 64 - sValLen), sValLen);
}
/**
* Builds Table 8-11 plaintext into {@code out[outOff..]}. Emits either
* {@code 0x4E key_slot} (first 8 bytes of SHA-1(uncompressed
* credential_PubK), per §8.3.3.4.2 + ref [12]) when command_parameters
* bit 0 = 0, or {@code 0x5A credential_PubK} (full uncompressed 65B)
* when bit 0 = 1. Then {@code 0x9E UD_signature} and a 2-byte
* all-zero {@code 0x5E signaling_bitmap}.
*/
private short buildTable811Plaintext(
byte auth1CmdParams, CredentialStore store,
byte[] rawSig, short rawSigOff, short rawSigLen,
byte[] out, short outOff) {
short p = outOff;
if ((auth1CmdParams & 0x01) == 0) {
// 0x4E 0x08 [key_slot] — first 8 bytes of SHA-1(uncompressed credential_PubK)
out[p++] = (byte) 0x4E;
out[p++] = (byte) 0x08;
p = appendKeySlot(store, out, p);
} else {
// 0x5A 0x41 [0x04 || x || y] — 65-byte uncompressed credential long-term pubkey
out[p++] = (byte) 0x5A;
out[p++] = (byte) 0x41;
out[p++] = (byte) 0x04;
store.copyCredentialPubKey(out, p);
p += CredentialStore.CRED_PUBK_LEN;
}
// 0x9E 0x40 [raw r||s UD signature]
out[p++] = (byte) 0x9E;
out[p++] = (byte) 0x40;
Util.arrayCopyNonAtomic(rawSig, rawSigOff, out, p, rawSigLen);
p += rawSigLen;
// 0x5E 0x02 [signaling_bitmap] — 16-bit big-endian. Bit 0: Access
// Document retrievable. Bit 2: retrieval requires step-up AID SELECT
// (applicable on NFC). Other bits unused in v1 (no mailbox/notify).
//
// We emit 0x0005 (bits 0 + 2) when an Access Document is provisioned.
// Honest reading of the spec would say we should leave these off
// until Step-up Phase is actually implemented (CBOR + mdoc + ENVELOPE
// + GET RESPONSE + AES-GCM over StepUpSK, §8.4), but empirically the
// closed-source ACWG_processAUTH1ResponsePayload() in X-CUBE-ALIRO's
// Aliro.a errors out when bits 0 + 2 are clear and AD is provisioned
// -- it expects "AD present" to be advertised. The bits are
// informational about capabilities anyway, not enforceable
// commitments, so 0x0005 satisfies the vendor library. AliroApplet
// now returns 6D00 for any post-AUTH1 INS like 0xC9 -- StepUpApplet
// at ACCE5502 handles ENVELOPE and EXCHANGE properly per spec §10.2
// + §8.4. Revisit when we test against more readers and can lean on
// the spec literally.
short bitmap = 0;
if (store.hasAccessDocument()) {
bitmap |= 0x0001; // bit 0
bitmap |= 0x0004; // bit 2 — NFC requires step-up AID to fetch AD
}
out[p++] = (byte) 0x5E;
out[p++] = (byte) 0x02;
out[p++] = (byte) ((bitmap >> 8) & 0xFF);
out[p++] = (byte) (bitmap & 0xFF);
return (short) (p - outOff);
}
/**
* Computes key_slot = first 8 bytes of SHA-1(uncompressed credential_PubK)
* and writes it to {@code out[p..p+8)}. Returns {@code p + 8}.
*
* <p>Uses scratch for both the 65-byte SHA-1 input and the 20-byte SHA-1
* output — the expensive phases (reader-sig verify, key derivation) have
* already finished by the time this runs, so scratch can be reused.
*/
private short appendKeySlot(CredentialStore store, byte[] out, short p) {
// Build uncompressed credential_PubK at scratch[0..65).
scratch[0] = (byte) 0x04;
store.copyCredentialPubKey(scratch, (short) 1);
// Hash into scratch[65..85).
sha1.reset();
sha1.doFinal(scratch, (short) 0, (short) 65, scratch, (short) 65);
Util.arrayCopyNonAtomic(scratch, (short) 65, out, p, (short) 8);
return (short) (p + 8);
}
/**
* AES-256-GCM encrypts {@code plaintext} with {@code ExpeditedSKDevice}
* (from {@link #derivedKeys}) and IV =
* {@code 0x0000000000000001 || expedited_device_counter (4B BE)},
* where the device_counter starts at 1 (spec §8.3.1.13) and is only
* incremented once a new phase begins. For the first AUTH1 response the
* counter is 1. Writes {@code ciphertext || tag} into {@code out[outOff..]}
* and returns {@code plaintextLen + 16}.
*
* <p>Uses {@link AliroGcm} — a userland GCM built on AES-ECB — because
* the target card (J3R180) does not expose {@code AEADCipher.ALG_AES_GCM}.
*/
private short encryptResponseGcm(
byte[] plaintext, short ptOff, short ptLen,
byte[] out, short outOff) {
// Build 12-byte IV in a small scratch region.
short ivOff = SCRATCH_RAW_SIG_OFF; // borrow scratch — sig already copied into plaintext
Util.arrayFillNonAtomic(scratch, ivOff, GCM_IV_LEN, (byte) 0);
scratch[(short) (ivOff + 7)] = (byte) 0x01; // fixed prefix low byte
// device_counter big-endian in the last 4 bytes; first AUTH1 = 1
scratch[(short) (ivOff + 11)] = (byte) 0x01;
return CryptoSingletons.getAliroGcm().encrypt(
derivedKeys, OFF_EXPEDITED_SK_DEVICE,
scratch, ivOff,
plaintext, ptOff, ptLen,
out, outOff);
}
/**
* Builds Table 8-12 (the bytes the reader signed) into the given buffer.
* Requires AUTH0 state to be captured and the credential ephemeral
* keypair to be fresh (both true by the time we get here).
* Returns the total number of bytes written.
*/
private short buildTable812(byte[] dst, short dstOff) {
short p = dstOff;
// reader_identifier (tag 0x4D, 32 bytes: group_id || group_sub_id)
dst[p++] = (byte) 0x4D;
dst[p++] = (byte) 0x20;
Util.arrayCopyNonAtomic(sessionState, OFF_READER_GROUP_ID, dst, p, (short) 32);
p += 32;
// credential_ePubK.x (tag 0x86, 32 bytes)
// Write full uncompressed point to a later scratch region, copy only the x part.
ECPublicKey credPub = (ECPublicKey) credentialEphemeralKeyPair.getPublic();
short credPubOff = SCRATCH_READER_PUB_UNCOMP_OFF; // reuse — we haven't written reader pub yet
credPub.getW(scratch, credPubOff);
dst[p++] = (byte) 0x86;
dst[p++] = (byte) 0x20;
Util.arrayCopyNonAtomic(scratch, (short) (credPubOff + 1), dst, p, (short) 32);
p += 32;
// reader_ePubK.x (tag 0x87, 32 bytes) — sessionState stores full uncompressed at OFF_READER_EPUBK
dst[p++] = (byte) 0x87;
dst[p++] = (byte) 0x20;
Util.arrayCopyNonAtomic(sessionState, (short) (OFF_READER_EPUBK + 1), dst, p, (short) 32);
p += 32;
// transaction_identifier (tag 0x4C, 16 bytes)
dst[p++] = (byte) 0x4C;
dst[p++] = (byte) 0x10;
Util.arrayCopyNonAtomic(sessionState, OFF_TRANSACTION_ID, dst, p, (short) 16);
p += 16;
// usage (tag 0x93, 4 bytes: 0x41 5D 95 69)
dst[p++] = (byte) 0x93;
dst[p++] = (byte) 0x04;
dst[p++] = (byte) 0x41;
dst[p++] = (byte) 0x5D;
dst[p++] = (byte) 0x95;
dst[p++] = (byte) 0x69;
return (short) (p - dstOff);
}
/**
* Converts a 64-byte raw ECDSA (r||s) signature into ASN.1 DER:
* {@code SEQUENCE { INTEGER r, INTEGER s }}. Both r and s are written
* without leading-zero stripping, and a 0x00 is prepended if the high
* bit of the first byte is set (to keep the INTEGER positive).
* Returns the number of DER bytes written.
*/
private static short rawSigToDer(byte[] raw, short rawOff, byte[] out, short outOff) {
boolean rPad = (raw[rawOff] & 0x80) != 0;
boolean sPad = (raw[(short) (rawOff + 32)] & 0x80) != 0;
short rLen = rPad ? (short) 33 : (short) 32;
short sLen = sPad ? (short) 33 : (short) 32;
short contentLen = (short) (2 + rLen + 2 + sLen);
short p = outOff;
out[p++] = (byte) 0x30;
out[p++] = (byte) contentLen;
out[p++] = (byte) 0x02;
out[p++] = (byte) rLen;
if (rPad) out[p++] = (byte) 0x00;
Util.arrayCopyNonAtomic(raw, rawOff, out, p, (short) 32);
p += 32;
out[p++] = (byte) 0x02;
out[p++] = (byte) sLen;
if (sPad) out[p++] = (byte) 0x00;
Util.arrayCopyNonAtomic(raw, (short) (rawOff + 32), out, p, (short) 32);
p += 32;
return (short) (p - outOff);
}
/**
* Walks AUTH1 command data, verifies the two mandatory tags (0x41 and
* 0x9E) with their expected lengths, rejects tag 0x90 (reader_Cert,
* unsupported in v1), and silently accepts unknown tags per spec
* &sect;1.4.3.
*/
private void validateAuth1Data(byte[] buf, short dataOff, short dataLen) {
if (dataLen <= 0) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
byte seen = 0;
short i = dataOff;
short end = (short) (dataOff + dataLen);
while (i < end) {
if ((short) (i + 2) > end) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
byte tag = buf[i];
short len = (short) (buf[(short) (i + 1)] & 0xFF);
short valueOff = (short) (i + 2);
if ((short) (valueOff + len) > end) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
switch (tag) {
case TAG_COMMAND_PARAMETERS:
requireLen(len, LEN_COMMAND_PARAMETERS);
sessionState[OFF_AUTH1_CMD_PARAMS] = buf[valueOff];
seen |= REQ_AUTH1_CMD_PARAMS;
break;
case TAG_READER_SIGNATURE:
requireLen(len, LEN_READER_SIGNATURE);
// Capture the sig for later use by verifyReaderSignature().
Util.arrayCopyNonAtomic(buf, valueOff, scratch, SCRATCH_RAW_SIG_OFF, len);
seen |= REQ_AUTH1_READER_SIG;
break;
case TAG_READER_CERT:
// v1 scope: certificates are out of scope. Reject explicitly.
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
break;
default:
// Unknown TLV — spec §1.4.3 says accept silently.
break;
}
i = (short) (valueOff + len);
}
if ((byte) (seen & REQ_ALL_AUTH1) != REQ_ALL_AUTH1) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
}
/**
* Builds and sends the FCI template for a successful SELECT of the
* expedited-phase AID, per spec &sect;10.2.1.
*
* <pre>
* 6F L1
* 84 09 [expedited AID]
* A5 L2
* 80 02 00 00 ; type = CSA application
* 5C 02 01 00 ; expedited protocol versions = {0x0100}
* </pre>
*/
private void sendExpeditedFci(APDU apdu) {
byte[] buf = apdu.getBuffer();
short off = 0;
buf[off++] = 0x6F;
short outerLenPos = off++;
buf[off++] = (byte) 0x84;
buf[off++] = (byte) AliroAids.EXPEDITED.length;
off = Util.arrayCopyNonAtomic(AliroAids.EXPEDITED, (short) 0,
buf, off, (short) AliroAids.EXPEDITED.length);
buf[off++] = (byte) 0xA5;
short propLenPos = off++;
short propStart = off;
buf[off++] = (byte) 0x80;
buf[off++] = (byte) 0x02;
buf[off++] = (byte) ((APP_TYPE_CSA >> 8) & 0xFF);
buf[off++] = (byte) (APP_TYPE_CSA & 0xFF);
buf[off++] = (byte) 0x5C;
buf[off++] = (byte) 0x02;
buf[off++] = (byte) ((PROTOCOL_VERSION_1_0 >> 8) & 0xFF);
buf[off++] = (byte) (PROTOCOL_VERSION_1_0 & 0xFF);
buf[propLenPos] = (byte) (off - propStart);
buf[outerLenPos] = (byte) (off - 2);
apdu.setOutgoingAndSend((short) 0, off);
}
/**
* Handles AUTH0 (spec &sect;8.3.3.2). Validates mandatory input TLVs,
* captures session state for AUTH1 (reader ephemeral pubkey,
* reader_group_id, reader_group_sub_id, transaction_identifier,
* command_parameters), generates a fresh credential ephemeral P-256
* keypair, and returns the ephemeral public key tagged 0x86.
*/
private void processAuth0(APDU apdu) {
// A new AUTH0 starts a new transaction; disarm any prior step-up
// state so a mid-pipeline failure later cannot leave stale StepUpSK
// reachable by SELECT STEP_UP.
SessionContext.disarmStepUp();
short lc = apdu.setIncomingAndReceive();
byte[] buf = apdu.getBuffer();
short dataOff = apdu.getOffsetCdata();
validateAuth0Data(buf, dataOff, lc);
// Diagnostic ladder for J3R180: EC keypair generation has historically
// been brittle on this card (see signingKeyParamsInitialized comment).
// Surface the CryptoException reason in the low nibble of the SW so we
// can tell ILLEGAL_VALUE/UNINITIALIZED_KEY/NO_SUCH_ALGORITHM apart on
// the bench. 0x6FEF = non-CryptoException Throwable.
try {
credentialEphemeralKeyPair.genKeyPair();
} catch (javacard.security.CryptoException e) {
ISOException.throwIt((short) (0x6FE0 | (e.getReason() & 0x000F)));
} catch (Throwable t) {
ISOException.throwIt((short) 0x6FEF);
}
ECPublicKey pub = (ECPublicKey) credentialEphemeralKeyPair.getPublic();
short off = 0;
buf[off++] = TAG_CREDENTIAL_EPUBK;
short lenPos = off++;
short keyLen = pub.getW(buf, off);
buf[lenPos] = (byte) keyLen;
off += keyLen;
sessionFlags[FLAG_AUTH0_DONE] = true;
apdu.setOutgoingAndSend((short) 0, off);
}
/**
* Walks the AUTH0 command data, verifies every mandatory TLV (tags,
* lengths, and protocol version value) is present, and rejects the
* command with SW=6A80 if anything required is missing or invalid.
* Unknown tags are silently skipped (spec &sect;1.4.3).
*/
private void validateAuth0Data(byte[] buf, short dataOff, short dataLen) {
if (dataLen <= 0) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
byte seen = 0;
short i = dataOff;
short end = (short) (dataOff + dataLen);
while (i < end) {
if ((short) (i + 2) > end) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
byte tag = buf[i];
short len = (short) (buf[(short) (i + 1)] & 0xFF);
short valueOff = (short) (i + 2);
if ((short) (valueOff + len) > end) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
switch (tag) {
case TAG_COMMAND_PARAMETERS:
requireLen(len, LEN_COMMAND_PARAMETERS);
sessionState[OFF_COMMAND_PARAMETERS] = buf[valueOff];
seen |= REQ_CMD_PARAMS;
break;
case TAG_AUTHENTICATION_POLICY:
requireLen(len, LEN_AUTHENTICATION_POLICY);
sessionState[OFF_AUTH_POLICY] = buf[valueOff];
seen |= REQ_AUTH_POLICY;
break;
case TAG_PROTOCOL_VERSION:
requireLen(len, LEN_PROTOCOL_VERSION);
short version = Util.getShort(buf, valueOff);
if (version != PROTOCOL_VERSION_1_0) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
seen |= REQ_PROTO_VER;
break;
case TAG_READER_EPUBK:
requireLen(len, LEN_READER_EPUBK);
if (buf[valueOff] != (byte) 0x04) {
// Must be uncompressed point per spec Table 8-4.
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
Util.arrayCopyNonAtomic(buf, valueOff, sessionState, OFF_READER_EPUBK, len);
seen |= REQ_READER_EPUBK;
break;
case TAG_TRANSACTION_ID:
requireLen(len, LEN_TRANSACTION_ID);
Util.arrayCopyNonAtomic(buf, valueOff, sessionState, OFF_TRANSACTION_ID, len);
seen |= REQ_TXN_ID;
break;
case TAG_READER_IDENTIFIER:
requireLen(len, LEN_READER_IDENTIFIER);
Util.arrayCopyNonAtomic(buf, valueOff, sessionState, OFF_READER_GROUP_ID, (short) 16);
Util.arrayCopyNonAtomic(buf, (short) (valueOff + 16), sessionState, OFF_READER_GROUP_SUB_ID, (short) 16);
seen |= REQ_READER_ID;
break;
default:
// Unknown TLV — spec §1.4.3 says accept silently.
break;
}
i = (short) (valueOff + len);
}
if ((byte) (seen & REQ_ALL_AUTH0) != REQ_ALL_AUTH0) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
}
private static void requireLen(short actual, short expected) {
if (actual != expected) {
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
}
}
Reference in New Issue View Git Blame Copy Permalink