Merge "Extend the default implementation of the secure element AIDL interface"
diff --git a/secure_element/aidl/default/main.cpp b/secure_element/aidl/default/main.cpp
index 16b8236..9b5a8fc 100644
--- a/secure_element/aidl/default/main.cpp
+++ b/secure_element/aidl/default/main.cpp
@@ -15,141 +15,673 @@
  */
 
 #include <aidl/android/hardware/secure_element/BnSecureElement.h>
-
 #include <android-base/hex.h>
 #include <android-base/logging.h>
 #include <android/binder_manager.h>
 #include <android/binder_process.h>
 
+#include <algorithm>
+
 using aidl::android::hardware::secure_element::BnSecureElement;
 using aidl::android::hardware::secure_element::ISecureElementCallback;
 using aidl::android::hardware::secure_element::LogicalChannelResponse;
 using android::base::HexString;
 using ndk::ScopedAStatus;
 
-static const std::vector<uint8_t> kAndroidTestAid = {0xA0, 0x00, 0x00, 0x04, 0x76, 0x41,
-                                                     0x6E, 0x64, 0x72, 0x6F, 0x69, 0x64,
-                                                     0x43, 0x54, 0x53, 0x31};
-static const std::vector<uint8_t> kLongAndroidTestAid = {0xA0, 0x00, 0x00, 0x04, 0x76, 0x41,
-                                                         0x6E, 0x64, 0x72, 0x6F, 0x69, 0x64,
-                                                         0x43, 0x54, 0x53, 0x32};
+static const std::vector<uint8_t> kIssuerSecurityDomainSelectResponse = {0x00, 0x00, 0x90, 0x00};
 
-class MySecureElement : public BnSecureElement {
+namespace se {
+// Application identifier.
+using Aid = std::vector<uint8_t>;
+
+// ISO7816 APDU status codes.
+enum Status : uint16_t {
+    SW_WRONG_DATA = 0x6A80,
+    SW_LOGICAL_CHANNEL_NOT_SUPPORTED = 0x6881,
+    SW_CONDITIONS_NOT_SATISFIED = 0x6985,
+    SW_INCORRECT_P1P2 = 0x6A86,
+    SW_BYTES_REMAINING_00 = 0x6100,
+    SW_WRONG_LENGTH = 0x6700,
+    SW_CORRECT_LENGTH_00 = 0x6C00,
+    SW_INS_NOT_SUPPORTED = 0x6D00,
+    SW_NO_ERROR = 0x9000,
+};
+
+// Type for raw APDUs.
+using RawApdu = std::vector<uint8_t>;
+
+// Wrap a command APDU (Application Processing Data Unit) to provide
+// accessors for header fields.
+struct Apdu {
   public:
-    ScopedAStatus closeChannel(int8_t channelNumber) override {
-        LOG(INFO) << __func__ << " channel number: " << channelNumber;
-        return ScopedAStatus::ok();
+    // Construct a command Apdu.
+    Apdu(std::vector<uint8_t> packet) : bytes_(std::move(packet)) {
+        CHECK(bytes_.size() >= kHeaderSize) << "command APDU created with invalid length";
+        size_t payload_len = bytes_.size() - kHeaderSize;
+
+        // TODO(b/123254068) - add support for extended command APDUs.
+        // Pre compute Lc and Le.
+
+        // Case 1: CLA | INS | P1 | P2
+        if (payload_len == 0) {
+            lc_ = 0;
+            le_ = 0;
+            return;
+        }
+
+        // Case 2: CLA | INS | P1 | P2 | Le
+        // Le has a value of 1 to 255.
+        if (payload_len == 1) {
+            le_ = bytes_[kHeaderSize];
+            le_ = le_ == 0 ? 256 : le_;
+            lc_ = 0;
+            return;
+        }
+
+        // Case 3: CLA | INS | P1 | P2 | Lc | Data
+        // Lc is less than 256 bytes
+        // of data, and Le is zero.
+        lc_ = bytes_[kHeaderSize];
+        if (payload_len <= (1 + lc_)) {
+            le_ = 0;
+        }
+
+        // Case 4: CLA | INS | P1 | P2 | Lc | Data | Le
+        // The legacy Case 4. Lc and Le
+        // are less than 256 bytes of data.
+        else {
+            le_ = bytes_[bytes_.size() - 1];
+            le_ = le_ == 0 ? 256 : le_;
+        }
     }
-    ScopedAStatus getAtr(std::vector<uint8_t>* _aidl_return) override {
-        LOG(INFO) << __func__;
-        _aidl_return->clear();
-        return ScopedAStatus::ok();
+
+    // Construct a response Apdu with data.
+    static RawApdu CreateResponse(std::vector<uint8_t> data, Status status) {
+        // Append status word.
+        data.push_back(status >> 8);
+        data.push_back(status);
+        return data;
     }
+
+    // Construct a response Apdu with no data.
+    static RawApdu CreateResponse(Status status) {
+        // Append status word.
+        return std::vector<uint8_t>{static_cast<uint8_t>(status >> 8),
+                                    static_cast<uint8_t>(status)};
+    }
+
+    // Return if command APDU is extended.
+    // The ISO/IEC 7816-4:2013 specification defines an extended APDU as any APDU
+    // whose payload data, response data or expected data length exceeds the 256
+    // byte limit.
+    bool IsExtended() const { return (bytes_.size() - kHeaderSize) > 256; }
+
+    // Return if command APDU has payload bytes.
+    bool HasPayload() const { return bytes_.size() > kHeaderSize; }
+
+    uint8_t get_cla() const { return bytes_[0]; }
+    uint8_t get_ins() const { return bytes_[1]; }
+    uint8_t get_p1() const { return bytes_[2]; }
+    uint8_t get_p2() const { return bytes_[3]; }
+
+    // Return the channel number encoded in the CLA field.
+    uint8_t get_channel_number() const {
+        // Type 4 commands — Encode legacy ISO/IEC 7816-4 logical channel
+        // information. Type 16 commands — Defined by the ISO/IEC 7816-4:2013
+        // specification to
+        //   encode information for additional 16 logical channels in the card.
+        uint8_t cla = get_cla();
+        return (cla & 0x40) == 0 ? cla & 0x3 : 4 + (cla & 0xf);
+    }
+
+    // Return the length of the command data field.
+    uint16_t get_lc() const { return lc_; }
+
+    // Return the expected length of the response data field.
+    // Le should be have the same format as Lc.
+    uint16_t get_le() const { return le_; }
+
+    // Get the pointer to the APDU raw data.
+    std::vector<uint8_t> const& get_data() const { return bytes_; }
+
+  private:
+    // Size of command header, including CLA, INS, P1, P2 fields.
+    const size_t kHeaderSize = 4;
+
+    // Command or response buffer.
+    std::vector<uint8_t> bytes_{};
+
+    // Lengths of command data field and expected response data field.
+    uint16_t lc_{0};
+    uint16_t le_{0};
+};
+
+// Type of SE applets.
+class Applet {
+  public:
+    virtual ~Applet() {}
+
+    // Called to inform this applet that it has been selected.
+    virtual RawApdu Select(Aid const& aid, uint8_t p2) = 0;
+
+    // Called by the Java Card runtime environment to process an
+    // incoming APDU command. SELECT commands are processed by \ref select
+    // instead.
+    virtual RawApdu Process(Apdu const& apdu) = 0;
+};
+};  // namespace se
+
+// Implement the Google-eSE-test.cap test applet for passing OMAPI CTS tests
+// on Cuttlefish. The reference can be found here:
+// cts/tests/tests/secure_element/sample_applet/src/com/android/cts/omapi/test/CtsAndroidOmapiTestApplet.java
+class CtsAndroidOmapiTestApplet : public se::Applet {
+  public:
+    CtsAndroidOmapiTestApplet() {}
+    virtual ~CtsAndroidOmapiTestApplet() {}
+
+    se::RawApdu Select(se::Aid const& aid, uint8_t /*p2*/) override {
+        if (aid[aid.size() - 1] == 0x31) {
+            // AID: A000000476416E64726F696443545331
+            return se::Apdu::CreateResponse(se::Status::SW_NO_ERROR);
+        } else {
+            // AID: A000000476416E64726F696443545332
+            return se::Apdu::CreateResponse(GenerateBerTLVBytes(SELECT_RESPONSE_DATA_LENGTH),
+                                            se::Status::SW_NO_ERROR);
+        }
+    }
+
+    se::RawApdu ReadNextResponseChunk(uint16_t max_output_len) {
+        uint16_t output_len = static_cast<uint16_t>(response_.size() - response_offset_);
+        output_len = std::min<uint16_t>(max_output_len, output_len);
+        std::vector<uint8_t> output{
+                &response_[response_offset_],
+                &response_[response_offset_ + output_len],
+        };
+        response_offset_ += output_len;
+        uint16_t remaining_len = response_.size() - response_offset_;
+        se::Status status = se::Status::SW_NO_ERROR;
+        if (remaining_len > 0) {
+            if (remaining_len > 256) {
+                remaining_len = 0x00;
+            }
+            status = se::Status(se::Status::SW_BYTES_REMAINING_00 | remaining_len);
+        } else {
+            response_.clear();
+            response_offset_ = 0;
+        }
+        return se::Apdu::CreateResponse(output, status);
+    }
+
+    se::RawApdu Process(se::Apdu const& apdu) override {
+        uint16_t lc;
+        uint16_t le = apdu.get_le();
+        uint8_t p1 = apdu.get_p1();
+        uint8_t p2 = apdu.get_p2();
+
+        switch (apdu.get_ins()) {
+            case NO_DATA_INS_1:
+            case NO_DATA_INS_2:
+                LOG(INFO) << __func__ << ": NO_DATA_INS_1|2";
+                return se::Apdu::CreateResponse(se::Status::SW_NO_ERROR);
+
+            case DATA_INS_1:
+            case DATA_INS_2:
+                // Return 256 bytes of data.
+                LOG(INFO) << __func__ << ": DATA_INS_1|2";
+                return se::Apdu::CreateResponse(GeneratesBytes(256), se::Status::SW_NO_ERROR);
+
+            case GET_RESPONSE_INS:
+                // ISO GET_RESPONSE command.
+                LOG(INFO) << __func__ << ": GET_RESPONSE_INS";
+                if (response_.empty()) {
+                    return se::Apdu::CreateResponse(se::Status::SW_CONDITIONS_NOT_SATISFIED);
+                }
+                return ReadNextResponseChunk(apdu.get_le());
+
+            case SW_62xx_APDU_INS:
+                LOG(INFO) << __func__ << ": SW_62xx_APDU_INS";
+                if (p1 < 1 || p1 > 16) {
+                    return se::Apdu::CreateResponse(se::Status::SW_INCORRECT_P1P2);
+                }
+                if (p2 == SW_62xx_DATA_APDU_P2) {
+                    return se::Apdu::CreateResponse(GeneratesBytes(3),
+                                                    se::Status(SW_62xx_resp[p1 - 1]));
+                }
+                if (p2 == SW_62xx_VALIDATE_DATA_P2) {
+                    std::vector<uint8_t> output{SW_62xx_VALIDATE_DATA_RESP.begin(),
+                                                SW_62xx_VALIDATE_DATA_RESP.end()};
+                    output[2] = p1;
+                    return se::Apdu::CreateResponse(std::move(output),
+                                                    se::Status(SW_62xx_resp[p1 - 1]));
+                }
+                return se::Apdu::CreateResponse(se::Status(SW_62xx_resp[p1 - 1]));
+
+            case SEGMENTED_RESP_INS_1:
+            case SEGMENTED_RESP_INS_2:
+                LOG(INFO) << __func__ << ": SEGMENTED_RESP_INS_1|2";
+                response_ = GeneratesBytes((static_cast<uint16_t>(p1) << 8) | p2);
+                response_offset_ = 0;
+                return ReadNextResponseChunk(std::min<uint16_t>(apdu.get_le(), 256));
+
+            case SEGMENTED_RESP_INS_3:
+            case SEGMENTED_RESP_INS_4:
+                LOG(INFO) << __func__ << ": SEGMENTED_RESP_INS_3|4";
+                response_ = GeneratesBytes((static_cast<uint16_t>(p1) << 8) | p2);
+                response_offset_ = 0;
+                return ReadNextResponseChunk(apdu.get_le());
+
+            case SEGMENTED_RESP_INS_5:
+                LOG(INFO) << __func__ << ": SEGMENTED_RESP_INS_5";
+                if (le == 0xff) {
+                    return se::Apdu::CreateResponse(
+                            se::Status(se::Status::SW_CORRECT_LENGTH_00 | 0xff));
+                }
+                response_ = GeneratesBytes((static_cast<uint16_t>(p1) << 8) | p2);
+                response_offset_ = 0;
+                return ReadNextResponseChunk(apdu.get_le());
+
+            case CHECK_SELECT_P2_APDU:
+                LOG(INFO) << __func__ << ": CHECK_SELECT_P2_APDU";
+                return se::Apdu::CreateResponse(std::vector<uint8_t>{apdu.get_p2()},
+                                                se::Status::SW_NO_ERROR);
+
+            default:
+                // Case is not known.
+                LOG(INFO) << __func__ << ": UNKNOWN_INS";
+                return se::Apdu::CreateResponse(se::Status::SW_INS_NOT_SUPPORTED);
+        }
+    }
+
+  private:
+    std::vector<uint8_t> response_{};
+    uint16_t response_offset_{0};
+
+    static const uint8_t NO_DATA_INS_1 = 0x06;
+    static const uint8_t NO_DATA_INS_2 = 0x0A;
+    static const uint8_t DATA_INS_1 = 0x08;
+    static const uint8_t DATA_INS_2 = 0x0C;
+    static const uint8_t SW_62xx_APDU_INS = 0xF3;
+    static const uint8_t SW_62xx_DATA_APDU_P2 = 0x08;
+    static const uint8_t SW_62xx_VALIDATE_DATA_P2 = 0x0C;
+
+    static constexpr std::array<uint8_t, 7> SW_62xx_VALIDATE_DATA_RESP = {0x01, 0xF3, 0x00, 0x0C,
+                                                                          0x01, 0xAA, 0x00};
+    static constexpr uint16_t SW_62xx_resp[] = {
+            0x6200, 0x6281, 0x6282, 0x6283, 0x6285, 0x62F1, 0x62F2, 0x63F1,
+            0x63F2, 0x63C2, 0x6202, 0x6280, 0x6284, 0x6286, 0x6300, 0x6381,
+    };
+
+    static const uint8_t SEGMENTED_RESP_INS_1 = 0xC2;
+    static const uint8_t SEGMENTED_RESP_INS_2 = 0xC4;
+    static const uint8_t SEGMENTED_RESP_INS_3 = 0xC6;
+    static const uint8_t SEGMENTED_RESP_INS_4 = 0xC8;
+    static const uint8_t SEGMENTED_RESP_INS_5 = 0xCF;
+    static const uint8_t CHECK_SELECT_P2_APDU = 0xF4;
+    static const uint8_t GET_RESPONSE_INS = 0xC0;
+    static const uint8_t BER_TLV_TYPE = 0x1F;
+    static const uint16_t SELECT_RESPONSE_DATA_LENGTH = 252;
+
+    static const uint16_t LENGTH_256 = 0x0100;
+    static constexpr std::array<uint8_t, 256> resp_bytes256{
+            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D,
+            0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B,
+            0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29,
+            0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+            0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45,
+            0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53,
+            0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61,
+            0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
+            0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D,
+            0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B,
+            0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99,
+            0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7,
+            0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5,
+            0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3,
+            0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1,
+            0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
+            0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED,
+            0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB,
+            0xFC, 0xFD, 0xFE, 0xFF};
+
+    // Generate a response buffer of the selected length containing valid
+    // BER TLV bytes.
+    static std::vector<uint8_t> GenerateBerTLVBytes(uint16_t le) {
+        // Support length from 0x00 - 0x7FFF.
+        uint16_t le_len = 1;
+        if (le < (uint16_t)0x80) {
+            le_len = 1;
+        } else if (le < (uint16_t)0x100) {
+            le_len = 2;
+        } else {
+            le_len = 3;
+        }
+
+        uint16_t total_len = (uint16_t)(le + 2 + le_len);
+        std::vector<uint8_t> output(total_len);
+        uint16_t i = 0;
+
+        output[i++] = BER_TLV_TYPE;
+        output[i++] = 0x00;  // second byte of Type
+        if (le < 0x80) {
+            output[i++] = le;
+        } else if (le < 0x100) {
+            output[i++] = 0x81;
+            output[i++] = le;
+        } else {
+            output[i++] = 0x82;
+            output[i++] = (le >> 8);
+            output[i++] = (le & 0xFF);
+        }
+        while (i < total_len) {
+            output[i++] = ((i - 2 - le_len) & 0xFF);
+        }
+
+        // Set the last byte to 0xFF for CTS validation.
+        output[total_len - 1] = 0xFF;
+        return output;
+    }
+
+    // Generate a response buffer of the selected length using the
+    // array resp_bytes256 as input.
+    static std::vector<uint8_t> GeneratesBytes(uint16_t total_len) {
+        std::vector<uint8_t> output(total_len);
+        uint16_t i = 0;
+
+        while (i < total_len) {
+            if ((total_len - i) >= resp_bytes256.size()) {
+                std::memcpy(&output[i], resp_bytes256.data(), resp_bytes256.size());
+                i += resp_bytes256.size();
+            } else {
+                output[i] = i & 0xFF;
+                i += 1;
+            }
+        }
+
+        // Set the last byte to 0xFF for CTS validation.
+        output[total_len - 1] = 0xFF;
+        return output;
+    }
+};
+
+class EmulatedSecureElement : public BnSecureElement {
+  public:
+    EmulatedSecureElement() {
+        std::shared_ptr<CtsAndroidOmapiTestApplet> test_applet =
+                std::make_shared<CtsAndroidOmapiTestApplet>();
+
+        applets_.push_back(std::pair{se::Aid{0xA0, 0x00, 0x00, 0x04, 0x76, 0x41, 0x6E, 0x64, 0x72,
+                                             0x6F, 0x69, 0x64, 0x43, 0x54, 0x53, 0x31},
+                                     test_applet});
+
+        applets_.push_back(std::pair{se::Aid{0xA0, 0x00, 0x00, 0x04, 0x76, 0x41, 0x6E, 0x64, 0x72,
+                                             0x6F, 0x69, 0x64, 0x43, 0x54, 0x53, 0x32},
+                                     test_applet});
+    }
+
     ScopedAStatus init(const std::shared_ptr<ISecureElementCallback>& clientCallback) override {
         LOG(INFO) << __func__ << " callback: " << clientCallback.get();
         if (!clientCallback) {
             return ScopedAStatus::fromExceptionCode(EX_NULL_POINTER);
         }
-        mCb = clientCallback;
-        mCb->onStateChange(true, "");
+        client_callback_ = clientCallback;
+        client_callback_->onStateChange(true, "init");
         return ScopedAStatus::ok();
     }
-    ScopedAStatus isCardPresent(bool* _aidl_return) override {
+
+    ScopedAStatus getAtr(std::vector<uint8_t>* aidl_return) override {
         LOG(INFO) << __func__;
-        *_aidl_return = true;
+        *aidl_return = atr_;
         return ScopedAStatus::ok();
     }
+
+    ScopedAStatus reset() override {
+        LOG(INFO) << __func__;
+        CHECK(client_callback_ != nullptr) << " init not invoked";
+        client_callback_->onStateChange(false, "reset");
+        client_callback_->onStateChange(true, "reset");
+        // All channels are closed after reset.
+        for (auto channel : channels_) {
+            channel = Channel();
+        }
+        return ScopedAStatus::ok();
+    }
+
+    ScopedAStatus isCardPresent(bool* aidl_return) override {
+        LOG(INFO) << __func__;
+        *aidl_return = true;
+        return ScopedAStatus::ok();
+    }
+
     ScopedAStatus openBasicChannel(const std::vector<uint8_t>& aid, int8_t p2,
-                                   std::vector<uint8_t>* _aidl_return) override {
+                                   std::vector<uint8_t>* aidl_return) override {
         LOG(INFO) << __func__ << " aid: " << HexString(aid.data(), aid.size()) << " (" << aid.size()
                   << ") p2 " << p2;
 
-        // TODO(b/123254068) - this is not an implementation of the OMAPI protocol or APDU.
-        // The functionality here is enough to exercise the framework, but actual
-        // calls to the secure element will fail. This implementation does not model
-        // channel isolation or any other aspects important to implementing secure element.
-        *_aidl_return = {0x90, 0x00, 0x00};  // DO NOT COPY
+        std::vector<uint8_t> select_response;
+        std::shared_ptr<se::Applet> applet = nullptr;
+
+        // The basic channel can only be opened once, and stays opened
+        // and locked until the channel is closed.
+        if (channels_[0].opened) {
+            LOG(INFO) << __func__ << " basic channel already opened";
+            return ScopedAStatus::fromServiceSpecificError(CHANNEL_NOT_AVAILABLE);
+        }
+
+        // If the AID is defined (the AID is not Null and the length of the
+        // AID is not 0) and the channel is not locked then the corresponding
+        // applet shall be selected.
+        if (aid.size() > 0) {
+            applet = SelectApplet(aid);
+            if (applet == nullptr) {
+                // No applet registered with matching AID.
+                LOG(INFO) << __func__ << " basic channel AID not found";
+                return ScopedAStatus::fromServiceSpecificError(NO_SUCH_ELEMENT_ERROR);
+            }
+            select_response = applet->Select(aid, p2);
+        }
+
+        // If the AID is a 0 length AID and the channel is not locked, the
+        // method will select the Issuer Security Domain of the SE by sending a
+        // SELECT command with a 0 length AID as defined in
+        // [GP Card specification].
+        if (aid.size() == 0) {
+            select_response = kIssuerSecurityDomainSelectResponse;
+        }
+
+        LOG(INFO) << __func__ << " sending response: "
+                  << HexString(select_response.data(), select_response.size());
+
+        // TODO(b/123254068) - this is not an implementation of the OMAPI protocol
+        // or APDU. The functionality here is enough to exercise the framework,
+        // but actual calls to the secure element will fail. This implementation
+        // does not model channel isolation or any other aspects important to
+        // implementing secure element.
+        channels_[0] = Channel(aid, p2, applet);
+        *aidl_return = select_response;
         return ScopedAStatus::ok();
     }
+
     ScopedAStatus openLogicalChannel(
             const std::vector<uint8_t>& aid, int8_t p2,
-            ::aidl::android::hardware::secure_element::LogicalChannelResponse* _aidl_return)
+            ::aidl::android::hardware::secure_element::LogicalChannelResponse* aidl_return)
             override {
         LOG(INFO) << __func__ << " aid: " << HexString(aid.data(), aid.size()) << " (" << aid.size()
                   << ") p2 " << p2;
 
-        if (aid != kAndroidTestAid && aid != kLongAndroidTestAid) {
-            return ScopedAStatus::fromServiceSpecificError(NO_SUCH_ELEMENT_ERROR);
+        size_t channel_number = 1;
+        std::vector<uint8_t> select_response;
+        std::shared_ptr<se::Applet> applet = nullptr;
+
+        // Look for an available channel number.
+        for (; channel_number < channels_.size(); channel_number++) {
+            if (channels_[channel_number].opened == false) {
+                break;
+            }
         }
 
-        *_aidl_return = LogicalChannelResponse{.channelNumber = 1, .selectResponse = {}};
+        // All channels are currently allocated.
+        if (channel_number >= channels_.size()) {
+            LOG(INFO) << __func__ << " all logical channels already opened";
+            return ScopedAStatus::fromServiceSpecificError(CHANNEL_NOT_AVAILABLE);
+        }
 
-        // TODO(b/123254068) - this is not an implementation of the OMAPI protocol or APDU.
-        // The functionality here is enough to exercise the framework, but actual
-        // calls to the secure element will fail. This implementation does not model
-        // channel isolation or any other aspects important to implementing secure element.
-        if (aid == kAndroidTestAid) {                                 // DO NOT COPY
-            size_t size = 2050;                                       // DO NOT COPY
-            _aidl_return->selectResponse.resize(size);                // DO NOT COPY
-            _aidl_return->selectResponse[size - 1] = 0x00;            // DO NOT COPY
-            _aidl_return->selectResponse[size - 2] = 0x90;            // DO NOT COPY
-        } else {                                                      // DO NOT COPY
-            _aidl_return->selectResponse = {0x00, 0x00, 0x90, 0x00};  // DO NOT COPY
-        }                                                             // DO NOT COPY
+        // If the AID is defined (the AID is not Null and the length of the
+        // AID is not 0) then the corresponding applet shall be selected.
+        if (aid.size() > 0) {
+            applet = SelectApplet(aid);
+            if (applet == nullptr) {
+                // No applet registered with matching AID.
+                LOG(INFO) << __func__ << " logical channel AID not found";
+                return ScopedAStatus::fromServiceSpecificError(NO_SUCH_ELEMENT_ERROR);
+            }
+            select_response = applet->Select(aid, p2);
+        }
+
+        // If the length of the AID is 0, the method will select the
+        // Issuer Security Domain of the SE by sending a SELECT command
+        // with 0 length AID as defined in [GPCS].
+        if (aid.size() == 0) {
+            select_response = kIssuerSecurityDomainSelectResponse;
+        }
 
         LOG(INFO) << __func__ << " sending response: "
-                  << HexString(_aidl_return->selectResponse.data(),
-                               _aidl_return->selectResponse.size());
+                  << HexString(select_response.data(), select_response.size());
 
+        // TODO(b/123254068) - this is not an implementation of the OMAPI protocol
+        // or APDU. The functionality here is enough to exercise the framework,
+        // but actual calls to the secure element will fail. This implementation
+        // does not model channel isolation or any other aspects important to
+        // implementing secure element.
+        channels_[channel_number] = Channel(aid, p2, applet);
+        *aidl_return = LogicalChannelResponse{
+                .channelNumber = static_cast<int8_t>(channel_number),
+                .selectResponse = select_response,
+        };
         return ScopedAStatus::ok();
     }
-    ScopedAStatus reset() override {
-        LOG(INFO) << __func__;
-        mCb->onStateChange(false, "reset");
-        mCb->onStateChange(true, "reset");
+
+    ScopedAStatus closeChannel(int8_t channel_number) override {
+        LOG(INFO) << __func__ << " channel number: " << static_cast<int>(channel_number);
+        // The selected basic or logical channel is not opened.
+        if (channel_number >= channels_.size() || !channels_[channel_number].opened) {
+            return ScopedAStatus::ok();
+        }
+
+        // TODO(b/123254068) - this is not an implementation of the OMAPI protocol
+        // or APDU. The functionality here is enough to exercise the framework,
+        // but actual calls to the secure element will fail. This implementation
+        // does not model channel isolation or any other aspects important to
+        // implementing secure element.
+        channels_[channel_number].opened = false;
         return ScopedAStatus::ok();
     }
+
     ScopedAStatus transmit(const std::vector<uint8_t>& data,
-                           std::vector<uint8_t>* _aidl_return) override {
+                           std::vector<uint8_t>* aidl_return) override {
         LOG(INFO) << __func__ << " data: " << HexString(data.data(), data.size()) << " ("
                   << data.size() << ")";
 
-        // TODO(b/123254068) - this is not an implementation of the OMAPI protocol or APDU.
-        // The functionality here is enough to exercise the framework, but actual
-        // calls to the secure element will fail. This implementation does not model
-        // channel isolation or any other aspects important to implementing secure element.
+        se::Apdu apdu(data);
+        uint8_t channel_number = apdu.get_channel_number();
+        std::vector<uint8_t> response_apdu;
 
-        std::string hex = HexString(data.data(), data.size());                    // DO NOT COPY
-        if (hex == "01a4040210a000000476416e64726f696443545331") {                // DO NOT COPY
-            *_aidl_return = {0x00, 0x6A, 0x00};                                   // DO NOT COPY
-        } else if (data == std::vector<uint8_t>{0x00, 0xF4, 0x00, 0x00, 0x00}) {  // DO NOT COPY
-            // CHECK_SELECT_P2_APDU w/ channel 1 // DO NOT COPY
-            *_aidl_return = {0x00, 0x90, 0x00};                                   // DO NOT COPY
-        } else if (data == std::vector<uint8_t>{0x01, 0xF4, 0x00, 0x00, 0x00}) {  // DO NOT COPY
-            // CHECK_SELECT_P2_APDU w/ channel 1 // DO NOT COPY
-            *_aidl_return = {0x00, 0x90, 0x00};             // DO NOT COPY
-        } else if (data.size() == 5 || data.size() == 8) {  // DO NOT COPY
-            // SEGMENTED_RESP_APDU - happens to use length 5 and 8 // DO NOT COPY
-            size_t size = (data[2] << 8 | data[3]) + 2;       // DO NOT COPY
-            _aidl_return->resize(size);                       // DO NOT COPY
-            (*_aidl_return)[size - 1] = 0x00;                 // DO NOT COPY
-            (*_aidl_return)[size - 2] = 0x90;                 // DO NOT COPY
-            if (size >= 3) (*_aidl_return)[size - 3] = 0xFF;  // DO NOT COPY
-        } else {                                              // DO NOT COPY
-            *_aidl_return = {0x90, 0x00, 0x00};               // DO NOT COPY
-        }                                                     // DO NOT COPY
+        switch (apdu.get_ins()) {
+            // TODO(b/123254068) - Implement support channel management APDUs.
+            case MANAGE_CHANNEL_INS:
+                // P1 = '00' to open
+                // P1 = '80' to close
+                LOG(INFO) << __func__ << " MANAGE_CHANNEL apdu";
+                response_apdu =
+                        se::Apdu::CreateResponse(se::Status::SW_LOGICAL_CHANNEL_NOT_SUPPORTED);
+                break;
 
+            // TODO(b/123254068) - Implement support channel management APDUs.
+            case SELECT_INS:
+                LOG(INFO) << __func__ << " SELECT apdu";
+                response_apdu =
+                        se::Apdu::CreateResponse(se::Status::SW_LOGICAL_CHANNEL_NOT_SUPPORTED);
+                break;
+
+            default:
+                CHECK(channel_number < channels_.size()) << " invalid channel number";
+                if (!channels_[channel_number].opened) {
+                    LOG(INFO) << __func__ << " the channel " << static_cast<int>(channel_number)
+                              << " is not opened";
+                    response_apdu =
+                            se::Apdu::CreateResponse(se::Status::SW_LOGICAL_CHANNEL_NOT_SUPPORTED);
+                    break;
+                }
+                // Send the APDU to the applet for processing.
+                // Applet implementation is optional, default to sending
+                // SW_INS_NOT_SUPPORTED.
+                if (channels_[channel_number].applet == nullptr) {
+                    response_apdu = se::Apdu::CreateResponse(se::Status::SW_INS_NOT_SUPPORTED);
+                } else {
+                    response_apdu = channels_[channel_number].applet->Process(apdu);
+                }
+                break;
+        }
+
+        aidl_return->assign(response_apdu.begin(), response_apdu.end());
+        LOG(INFO) << __func__
+                  << " response: " << HexString(aidl_return->data(), aidl_return->size()) << " ("
+                  << aidl_return->size() << ")";
         return ScopedAStatus::ok();
     }
 
   private:
-    std::shared_ptr<ISecureElementCallback> mCb;
+    struct Channel {
+      public:
+        Channel() = default;
+        Channel(Channel const&) = default;
+        Channel(se::Aid const& aid, uint8_t p2, std::shared_ptr<se::Applet> applet)
+            : opened(true), aid(aid), p2(p2), applet(std::move(applet)) {}
+        Channel& operator=(Channel const&) = default;
+
+        bool opened{false};
+        se::Aid aid{};
+        uint8_t p2{0};
+        std::shared_ptr<se::Applet> applet{nullptr};
+    };
+
+    // OMAPI abstraction.
+
+    // Channel 0 is the basic channel, channels 1-19 are the logical channels.
+    std::array<Channel, 20> channels_{};
+    std::shared_ptr<ISecureElementCallback> client_callback_;
+
+    // Secure element abstraction.
+
+    static const uint8_t MANAGE_CHANNEL_INS = 0x70;
+    static const uint8_t SELECT_INS = 0xa4;
+
+    // Secure element ATR (Answer-To-Reset).
+    // The format is specified by ISO/IEC 1816-4 2020 and lists
+    // the capabilities of the card.
+    //
+    // TODO(b/123254068): encode the default SE properties in the ATR:
+    // support for extended Lc / Le fields, maximum number of logical channels.
+    // The CTS tests are *not* checking this value.
+    std::vector<uint8_t> const atr_{};
+
+    // Applet registration.
+    std::vector<std::pair<se::Aid, std::shared_ptr<se::Applet>>> applets_{};
+
+    // Return the first applet that matches the selected aid.
+    std::shared_ptr<se::Applet> SelectApplet(se::Aid const& aid) {
+        for (auto& [applet_aid, applet] : applets_) {
+            if (applet_aid == aid) {
+                return applet;
+            }
+        }
+        return nullptr;
+    }
 };
 
 int main() {
     ABinderProcess_setThreadPoolMaxThreadCount(0);
 
-    auto se = ndk::SharedRefBase::make<MySecureElement>();
+    auto se = ndk::SharedRefBase::make<EmulatedSecureElement>();
     const std::string name = std::string() + BnSecureElement::descriptor + "/eSE1";
     binder_status_t status = AServiceManager_addService(se->asBinder().get(), name.c_str());
     CHECK_EQ(status, STATUS_OK);