move to new cspot

components/spotify/cspot/bell/main/utilities/BellLogger.cpp

@@ -0,0 +1,11 @@
+#include "BellLogger.h"
+
+bell::AbstractLogger* bell::bellGlobalLogger;
+
+void bell::setDefaultLogger() {
+    bell::bellGlobalLogger = new bell::BellLogger();
+}
+
+void bell::enableSubmoduleLogging() {
+    bell::bellGlobalLogger->enableSubmodule = true;
+}

components/spotify/cspot/bell/main/utilities/BellUtils.cpp

@@ -0,0 +1,37 @@
+#include "BellUtils.h"
+
+std::string bell::generateRandomUUID() {
+  static std::random_device dev;
+  static std::mt19937 rng(dev());
+
+  std::uniform_int_distribution<int> dist(0, 15);
+
+  const char* v = "0123456789abcdef";
+  const bool dash[] = {0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0};
+
+  std::string res;
+  for (int i = 0; i < 16; i++) {
+    if (dash[i])
+      res += "-";
+    res += v[dist(rng)];
+    res += v[dist(rng)];
+  }
+  return res;
+}
+
+std::string bell::getMacAddress() {
+#ifdef ESP_PLATFORM
+  uint8_t mac[6];
+  esp_read_mac(mac, ESP_MAC_WIFI_STA);
+  char macStr[18];
+  sprintf(macStr, "%02x:%02x:%02x:%02x:%02x:%02x", mac[0], mac[1], mac[2],
+          mac[3], mac[4], mac[5]);
+  return std::string(macStr);
+#endif
+  return "00:00:00:00:00:00";
+}
+
+void bell::freeAndNull(void*& ptr) {
+  free(ptr);
+  ptr = nullptr;
+}

components/spotify/cspot/bell/main/utilities/Crypto.cpp

@@ -0,0 +1,219 @@
+#include "Crypto.h"
+
+CryptoMbedTLS::CryptoMbedTLS() {}
+
+CryptoMbedTLS::~CryptoMbedTLS() {
+  if (aesCtxInitialized) {
+    mbedtls_aes_free(&aesCtx);
+  }
+}
+
+std::vector<uint8_t> CryptoMbedTLS::base64Decode(const std::string& data) {
+  // Calculate max decode length
+  size_t requiredSize;
+
+  mbedtls_base64_encode(nullptr, 0, &requiredSize, (unsigned char*)data.c_str(),
+                        data.size());
+
+  std::vector<uint8_t> output(requiredSize);
+  size_t outputLen = 0;
+  mbedtls_base64_decode(output.data(), requiredSize, &outputLen,
+                        (unsigned char*)data.c_str(), data.size());
+
+  return std::vector<uint8_t>(output.begin(), output.begin() + outputLen);
+}
+
+std::string CryptoMbedTLS::base64Encode(const std::vector<uint8_t>& data) {
+  // Calculate max output length
+  size_t requiredSize;
+  mbedtls_base64_encode(nullptr, 0, &requiredSize, data.data(), data.size());
+
+  std::vector<uint8_t> output(requiredSize);
+  size_t outputLen = 0;
+
+  mbedtls_base64_encode(output.data(), requiredSize, &outputLen, data.data(),
+                        data.size());
+
+  return std::string(output.begin(), output.begin() + outputLen);
+}
+
+// Sha1
+void CryptoMbedTLS::sha1Init() {
+  // Init mbedtls md context, pick sha1
+  mbedtls_md_init(&sha1Context);
+  mbedtls_md_setup(&sha1Context, mbedtls_md_info_from_type(MBEDTLS_MD_SHA1), 1);
+  mbedtls_md_starts(&sha1Context);
+}
+
+void CryptoMbedTLS::sha1Update(const std::string& s) {
+  sha1Update(std::vector<uint8_t>(s.begin(), s.end()));
+}
+void CryptoMbedTLS::sha1Update(const std::vector<uint8_t>& vec) {
+  mbedtls_md_update(&sha1Context, vec.data(), vec.size());
+}
+
+std::vector<uint8_t> CryptoMbedTLS::sha1FinalBytes() {
+  std::vector<uint8_t> digest(20);  // SHA1 digest size
+
+  mbedtls_md_finish(&sha1Context, digest.data());
+  mbedtls_md_free(&sha1Context);
+
+  return digest;
+}
+
+std::string CryptoMbedTLS::sha1Final() {
+  auto digest = sha1FinalBytes();
+  return std::string(digest.begin(), digest.end());
+}
+
+// HMAC SHA1
+std::vector<uint8_t> CryptoMbedTLS::sha1HMAC(
+    const std::vector<uint8_t>& inputKey, const std::vector<uint8_t>& message) {
+  std::vector<uint8_t> digest(20);  // SHA1 digest size
+
+  sha1Init();
+  mbedtls_md_hmac_starts(&sha1Context, inputKey.data(), inputKey.size());
+  mbedtls_md_hmac_update(&sha1Context, message.data(), message.size());
+  mbedtls_md_hmac_finish(&sha1Context, digest.data());
+  mbedtls_md_free(&sha1Context);
+
+  return digest;
+}
+
+// AES CTR
+void CryptoMbedTLS::aesCTRXcrypt(const std::vector<uint8_t>& key,
+                                 std::vector<uint8_t>& iv, uint8_t* buffer,
+                                 size_t nbytes) {
+  if (!aesCtxInitialized) {
+    mbedtls_aes_init(&aesCtx);
+    aesCtxInitialized = true;
+  }
+  // needed for internal cache
+  size_t off = 0;
+  unsigned char streamBlock[16] = {0};
+
+  // set IV
+  if (mbedtls_aes_setkey_enc(&aesCtx, key.data(), key.size() * 8) != 0) {
+    throw std::runtime_error("Failed to set AES key");
+  }
+  // Perform decrypt
+  if (mbedtls_aes_crypt_ctr(&aesCtx, nbytes, &off, iv.data(), streamBlock,
+                            buffer, buffer) != 0) {
+    throw std::runtime_error("Failed to decrypt");
+  }
+}
+
+void CryptoMbedTLS::aesECBdecrypt(const std::vector<uint8_t>& key,
+                                  std::vector<uint8_t>& data) {
+
+  struct AES_ctx aesCtr;
+  AES_init_ctx(&aesCtr, key.data());
+
+  for (unsigned int x = 0; x < data.size() / 16; x++) {
+
+    AES_ECB_decrypt(&aesCtr, data.data() + (x * 16));
+  }
+}
+
+// PBKDF2
+std::vector<uint8_t> CryptoMbedTLS::pbkdf2HmacSha1(
+    const std::vector<uint8_t>& password, const std::vector<uint8_t>& salt,
+    int iterations, int digestSize) {
+  auto digest = std::vector<uint8_t>(digestSize);
+
+  // Init sha context
+  sha1Init();
+  mbedtls_pkcs5_pbkdf2_hmac(&sha1Context, password.data(), password.size(),
+                            salt.data(), salt.size(), iterations, digestSize,
+                            digest.data());
+
+  // Free sha context
+  mbedtls_md_free(&sha1Context);
+
+  return digest;
+}
+
+void CryptoMbedTLS::dhInit() {
+  privateKey = generateVectorWithRandomData(DH_KEY_SIZE);
+
+  // initialize big num
+  mbedtls_mpi prime, generator, res, privKey;
+  mbedtls_mpi_init(&prime);
+  mbedtls_mpi_init(&generator);
+  mbedtls_mpi_init(&privKey);
+  mbedtls_mpi_init(&res);
+
+  // Read bin into big num mpi
+  mbedtls_mpi_read_binary(&prime, DHPrime, sizeof(DHPrime));
+  mbedtls_mpi_read_binary(&generator, DHGenerator, sizeof(DHGenerator));
+  mbedtls_mpi_read_binary(&privKey, privateKey.data(), DH_KEY_SIZE);
+
+  // perform diffie hellman G^X mod P
+  mbedtls_mpi_exp_mod(&res, &generator, &privKey, &prime, NULL);
+
+  // Write generated public key to vector
+  this->publicKey = std::vector<uint8_t>(DH_KEY_SIZE);
+  mbedtls_mpi_write_binary(&res, publicKey.data(), DH_KEY_SIZE);
+
+  // Release memory
+  mbedtls_mpi_free(&prime);
+  mbedtls_mpi_free(&generator);
+  mbedtls_mpi_free(&privKey);
+  mbedtls_mpi_free(&res);
+}
+
+std::vector<uint8_t> CryptoMbedTLS::dhCalculateShared(
+    const std::vector<uint8_t>& remoteKey) {
+  // initialize big num
+  mbedtls_mpi prime, remKey, res, privKey;
+  mbedtls_mpi_init(&prime);
+  mbedtls_mpi_init(&remKey);
+  mbedtls_mpi_init(&privKey);
+  mbedtls_mpi_init(&res);
+
+  // Read bin into big num mpi
+  mbedtls_mpi_read_binary(&prime, DHPrime, sizeof(DHPrime));
+  mbedtls_mpi_read_binary(&remKey, remoteKey.data(), remoteKey.size());
+  mbedtls_mpi_read_binary(&privKey, privateKey.data(), DH_KEY_SIZE);
+
+  // perform diffie hellman (G^Y)^X mod P (for shared secret)
+  mbedtls_mpi_exp_mod(&res, &remKey, &privKey, &prime, NULL);
+
+  auto sharedKey = std::vector<uint8_t>(DH_KEY_SIZE);
+  mbedtls_mpi_write_binary(&res, sharedKey.data(), DH_KEY_SIZE);
+
+  // Release memory
+  mbedtls_mpi_free(&prime);
+  mbedtls_mpi_free(&remKey);
+  mbedtls_mpi_free(&privKey);
+  mbedtls_mpi_free(&res);
+
+  return sharedKey;
+}
+
+// Random stuff
+std::vector<uint8_t> CryptoMbedTLS::generateVectorWithRandomData(
+    size_t length) {
+  std::vector<uint8_t> randomVector(length);
+  mbedtls_entropy_context entropy;
+  mbedtls_ctr_drbg_context ctrDrbg;
+  // Personification string
+  const char* pers = "cspotGen";
+
+  // init entropy and random num generator
+  mbedtls_entropy_init(&entropy);
+  mbedtls_ctr_drbg_init(&ctrDrbg);
+
+  // Seed the generator
+  mbedtls_ctr_drbg_seed(&ctrDrbg, mbedtls_entropy_func, &entropy,
+                        (const unsigned char*)pers, 7);
+
+  // Generate random bytes
+  mbedtls_ctr_drbg_random(&ctrDrbg, randomVector.data(), length);
+
+  // Release memory
+  mbedtls_entropy_free(&entropy);
+  mbedtls_ctr_drbg_free(&ctrDrbg);
+
+  return randomVector;
+}

components/spotify/cspot/bell/main/utilities/NanoPBHelper.cpp

@@ -0,0 +1,78 @@
+#include "NanoPBHelper.h"
+
+static bool vectorWrite(pb_ostream_t *stream, const pb_byte_t *buf, size_t count)
+{
+    size_t i;
+    auto *dest = reinterpret_cast<std::vector<uint8_t> *>(stream->state);
+
+    dest->insert(dest->end(), buf, buf + count);
+
+    return true;
+}
+
+pb_ostream_t pb_ostream_from_vector(std::vector<uint8_t> &vec)
+{
+    pb_ostream_t stream;
+
+    stream.callback = &vectorWrite;
+    stream.state = &vec;
+    stream.max_size = 100000;
+    stream.bytes_written = 0;
+
+    return stream;
+}
+
+std::vector<uint8_t> pbEncode(const pb_msgdesc_t *fields, const void *src_struct)
+{
+    std::vector<uint8_t> vecData(0);
+    pb_ostream_t stream = pb_ostream_from_vector(vecData);
+    pb_encode(&stream, fields, src_struct);
+
+    return vecData;
+}
+
+void packString(char *&dst, std::string stringToPack)
+{
+    dst = (char *)malloc((strlen(stringToPack.c_str()) + 1) * sizeof(char));
+    strcpy(dst, stringToPack.c_str());
+}
+
+pb_bytes_array_t* vectorToPbArray(const std::vector<uint8_t>& vectorToPack)
+{
+    auto size = static_cast<pb_size_t>(vectorToPack.size());
+    auto result = static_cast<pb_bytes_array_t *>(
+        malloc(PB_BYTES_ARRAY_T_ALLOCSIZE(size)));
+    result->size = size;
+    memcpy(result->bytes, vectorToPack.data(), size);
+    return result;
+}
+
+void pbPutString(const std::string &stringToPack, char* dst) {
+    stringToPack.copy(dst, stringToPack.size());
+    dst[stringToPack.size()] = '\0';
+}
+
+void pbPutCharArray(const char * stringToPack, char* dst) {
+    // copy stringToPack into dst
+    strcpy(dst, stringToPack);
+    //dst[sizeof(stringToPack)-1] = '\0';
+}
+
+void pbPutBytes(const std::vector<uint8_t> &data, pb_bytes_array_t &dst) {
+    dst.size = data.size();
+    std::copy(data.begin(), data.end(), dst.bytes);
+}
+
+std::vector<uint8_t> pbArrayToVector(pb_bytes_array_t* pbArray) {
+    return std::vector<uint8_t>(pbArray->bytes, pbArray->bytes + pbArray->size);
+}
+
+const char *pb_encode_to_string(const pb_msgdesc_t *fields, const void *data) {
+	size_t len;
+	pb_get_encoded_size(&len, fields, data);
+	auto *buf = static_cast<uint8_t *>(malloc(len + 1));
+	auto ostream = pb_ostream_from_buffer(buf, len);
+	pb_encode(&ostream, fields, data);
+	buf[len] = '\0';
+	return reinterpret_cast<const char *>(buf);
+}

components/spotify/cspot/bell/main/utilities/aes.c

@@ -0,0 +1,571 @@
+/*
+
+This is an implementation of the AES algorithm, specifically ECB, CTR and CBC mode.
+Block size can be chosen in aes.h - available choices are AES128, AES192, AES256.
+
+The implementation is verified against the test vectors in:
+  National Institute of Standards and Technology Special Publication 800-38A 2001 ED
+
+ECB-AES128
+----------
+
+  plain-text:
+    6bc1bee22e409f96e93d7e117393172a
+    ae2d8a571e03ac9c9eb76fac45af8e51
+    30c81c46a35ce411e5fbc1191a0a52ef
+    f69f2445df4f9b17ad2b417be66c3710
+
+  key:
+    2b7e151628aed2a6abf7158809cf4f3c
+
+  resulting cipher
+    3ad77bb40d7a3660a89ecaf32466ef97 
+    f5d3d58503b9699de785895a96fdbaaf 
+    43b1cd7f598ece23881b00e3ed030688 
+    7b0c785e27e8ad3f8223207104725dd4 
+
+
+NOTE:   String length must be evenly divisible by 16byte (str_len % 16 == 0)
+        You should pad the end of the string with zeros if this is not the case.
+        For AES192/256 the key size is proportionally larger.
+
+*/
+
+
+/*****************************************************************************/
+/* Includes:                                                                 */
+/*****************************************************************************/
+#include <string.h> // CBC mode, for memset
+#include "aes.h"
+
+/*****************************************************************************/
+/* Defines:                                                                  */
+/*****************************************************************************/
+// The number of columns comprising a state in AES. This is a constant in AES. Value=4
+#define Nb 4
+
+#if defined(AES256) && (AES256 == 1)
+    #define Nk 8
+    #define Nr 14
+#elif defined(AES192) && (AES192 == 1)
+    #define Nk 6
+    #define Nr 12
+#else
+    #define Nk 4        // The number of 32 bit words in a key.
+    #define Nr 10       // The number of rounds in AES Cipher.
+#endif
+
+// jcallan@github points out that declaring Multiply as a function 
+// reduces code size considerably with the Keil ARM compiler.
+// See this link for more information: https://github.com/kokke/tiny-AES-C/pull/3
+#ifndef MULTIPLY_AS_A_FUNCTION
+  #define MULTIPLY_AS_A_FUNCTION 0
+#endif
+
+
+
+
+/*****************************************************************************/
+/* Private variables:                                                        */
+/*****************************************************************************/
+// state - array holding the intermediate results during decryption.
+typedef uint8_t state_t[4][4];
+
+
+
+// The lookup-tables are marked const so they can be placed in read-only storage instead of RAM
+// The numbers below can be computed dynamically trading ROM for RAM - 
+// This can be useful in (embedded) bootloader applications, where ROM is often limited.
+static const uint8_t sbox[256] = {
+  //0     1    2      3     4    5     6     7      8    9     A      B    C     D     E     F
+  0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
+  0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
+  0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
+  0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
+  0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
+  0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
+  0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
+  0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
+  0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
+  0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
+  0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
+  0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
+  0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
+  0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
+  0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
+  0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 };
+
+#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
+static const uint8_t rsbox[256] = {
+  0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
+  0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
+  0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
+  0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
+  0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
+  0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
+  0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
+  0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
+  0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
+  0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
+  0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
+  0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
+  0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
+  0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
+  0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
+  0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d };
+#endif
+
+// The round constant word array, Rcon[i], contains the values given by 
+// x to the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
+static const uint8_t Rcon[11] = {
+  0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 };
+
+/*
+ * Jordan Goulder points out in PR #12 (https://github.com/kokke/tiny-AES-C/pull/12),
+ * that you can remove most of the elements in the Rcon array, because they are unused.
+ *
+ * From Wikipedia's article on the Rijndael key schedule @ https://en.wikipedia.org/wiki/Rijndael_key_schedule#Rcon
+ * 
+ * "Only the first some of these constants are actually used – up to rcon[10] for AES-128 (as 11 round keys are needed), 
+ *  up to rcon[8] for AES-192, up to rcon[7] for AES-256. rcon[0] is not used in AES algorithm."
+ */
+
+
+/*****************************************************************************/
+/* Private functions:                                                        */
+/*****************************************************************************/
+/*
+static uint8_t getSBoxValue(uint8_t num)
+{
+  return sbox[num];
+}
+*/
+#define getSBoxValue(num) (sbox[(num)])
+
+// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states. 
+static void KeyExpansion(uint8_t* RoundKey, const uint8_t* Key)
+{
+  unsigned i, j, k;
+  uint8_t tempa[4]; // Used for the column/row operations
+  
+  // The first round key is the key itself.
+  for (i = 0; i < Nk; ++i)
+  {
+    RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];
+    RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];
+    RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];
+    RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];
+  }
+
+  // All other round keys are found from the previous round keys.
+  for (i = Nk; i < Nb * (Nr + 1); ++i)
+  {
+    {
+      k = (i - 1) * 4;
+      tempa[0]=RoundKey[k + 0];
+      tempa[1]=RoundKey[k + 1];
+      tempa[2]=RoundKey[k + 2];
+      tempa[3]=RoundKey[k + 3];
+
+    }
+
+    if (i % Nk == 0)
+    {
+      // This function shifts the 4 bytes in a word to the left once.
+      // [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
+
+      // Function RotWord()
+      {
+        const uint8_t u8tmp = tempa[0];
+        tempa[0] = tempa[1];
+        tempa[1] = tempa[2];
+        tempa[2] = tempa[3];
+        tempa[3] = u8tmp;
+      }
+
+      // SubWord() is a function that takes a four-byte input word and 
+      // applies the S-box to each of the four bytes to produce an output word.
+
+      // Function Subword()
+      {
+        tempa[0] = getSBoxValue(tempa[0]);
+        tempa[1] = getSBoxValue(tempa[1]);
+        tempa[2] = getSBoxValue(tempa[2]);
+        tempa[3] = getSBoxValue(tempa[3]);
+      }
+
+      tempa[0] = tempa[0] ^ Rcon[i/Nk];
+    }
+#if defined(AES256) && (AES256 == 1)
+    if (i % Nk == 4)
+    {
+      // Function Subword()
+      {
+        tempa[0] = getSBoxValue(tempa[0]);
+        tempa[1] = getSBoxValue(tempa[1]);
+        tempa[2] = getSBoxValue(tempa[2]);
+        tempa[3] = getSBoxValue(tempa[3]);
+      }
+    }
+#endif
+    j = i * 4; k=(i - Nk) * 4;
+    RoundKey[j + 0] = RoundKey[k + 0] ^ tempa[0];
+    RoundKey[j + 1] = RoundKey[k + 1] ^ tempa[1];
+    RoundKey[j + 2] = RoundKey[k + 2] ^ tempa[2];
+    RoundKey[j + 3] = RoundKey[k + 3] ^ tempa[3];
+  }
+}
+
+void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key)
+{
+  KeyExpansion(ctx->RoundKey, key);
+}
+#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
+void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv)
+{
+  KeyExpansion(ctx->RoundKey, key);
+  memcpy (ctx->Iv, iv, AES_BLOCKLEN);
+}
+void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv)
+{
+  memcpy (ctx->Iv, iv, AES_BLOCKLEN);
+}
+#endif
+
+// This function adds the round key to state.
+// The round key is added to the state by an XOR function.
+static void AddRoundKey(uint8_t round, state_t* state, const uint8_t* RoundKey)
+{
+  uint8_t i,j;
+  for (i = 0; i < 4; ++i)
+  {
+    for (j = 0; j < 4; ++j)
+    {
+      (*state)[i][j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j];
+    }
+  }
+}
+
+// The SubBytes Function Substitutes the values in the
+// state matrix with values in an S-box.
+static void SubBytes(state_t* state)
+{
+  uint8_t i, j;
+  for (i = 0; i < 4; ++i)
+  {
+    for (j = 0; j < 4; ++j)
+    {
+      (*state)[j][i] = getSBoxValue((*state)[j][i]);
+    }
+  }
+}
+
+// The ShiftRows() function shifts the rows in the state to the left.
+// Each row is shifted with different offset.
+// Offset = Row number. So the first row is not shifted.
+static void ShiftRows(state_t* state)
+{
+  uint8_t temp;
+
+  // Rotate first row 1 columns to left  
+  temp           = (*state)[0][1];
+  (*state)[0][1] = (*state)[1][1];
+  (*state)[1][1] = (*state)[2][1];
+  (*state)[2][1] = (*state)[3][1];
+  (*state)[3][1] = temp;
+
+  // Rotate second row 2 columns to left  
+  temp           = (*state)[0][2];
+  (*state)[0][2] = (*state)[2][2];
+  (*state)[2][2] = temp;
+
+  temp           = (*state)[1][2];
+  (*state)[1][2] = (*state)[3][2];
+  (*state)[3][2] = temp;
+
+  // Rotate third row 3 columns to left
+  temp           = (*state)[0][3];
+  (*state)[0][3] = (*state)[3][3];
+  (*state)[3][3] = (*state)[2][3];
+  (*state)[2][3] = (*state)[1][3];
+  (*state)[1][3] = temp;
+}
+
+static uint8_t xtime(uint8_t x)
+{
+  return ((x<<1) ^ (((x>>7) & 1) * 0x1b));
+}
+
+// MixColumns function mixes the columns of the state matrix
+static void MixColumns(state_t* state)
+{
+  uint8_t i;
+  uint8_t Tmp, Tm, t;
+  for (i = 0; i < 4; ++i)
+  {  
+    t   = (*state)[i][0];
+    Tmp = (*state)[i][0] ^ (*state)[i][1] ^ (*state)[i][2] ^ (*state)[i][3] ;
+    Tm  = (*state)[i][0] ^ (*state)[i][1] ; Tm = xtime(Tm);  (*state)[i][0] ^= Tm ^ Tmp ;
+    Tm  = (*state)[i][1] ^ (*state)[i][2] ; Tm = xtime(Tm);  (*state)[i][1] ^= Tm ^ Tmp ;
+    Tm  = (*state)[i][2] ^ (*state)[i][3] ; Tm = xtime(Tm);  (*state)[i][2] ^= Tm ^ Tmp ;
+    Tm  = (*state)[i][3] ^ t ;              Tm = xtime(Tm);  (*state)[i][3] ^= Tm ^ Tmp ;
+  }
+}
+
+// Multiply is used to multiply numbers in the field GF(2^8)
+// Note: The last call to xtime() is unneeded, but often ends up generating a smaller binary
+//       The compiler seems to be able to vectorize the operation better this way.
+//       See https://github.com/kokke/tiny-AES-c/pull/34
+#if MULTIPLY_AS_A_FUNCTION
+static uint8_t Multiply(uint8_t x, uint8_t y)
+{
+  return (((y & 1) * x) ^
+       ((y>>1 & 1) * xtime(x)) ^
+       ((y>>2 & 1) * xtime(xtime(x))) ^
+       ((y>>3 & 1) * xtime(xtime(xtime(x)))) ^
+       ((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */
+  }
+#else
+#define Multiply(x, y)                                \
+      (  ((y & 1) * x) ^                              \
+      ((y>>1 & 1) * xtime(x)) ^                       \
+      ((y>>2 & 1) * xtime(xtime(x))) ^                \
+      ((y>>3 & 1) * xtime(xtime(xtime(x)))) ^         \
+      ((y>>4 & 1) * xtime(xtime(xtime(xtime(x))))))   \
+
+#endif
+
+#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
+/*
+static uint8_t getSBoxInvert(uint8_t num)
+{
+  return rsbox[num];
+}
+*/
+#define getSBoxInvert(num) (rsbox[(num)])
+
+// MixColumns function mixes the columns of the state matrix.
+// The method used to multiply may be difficult to understand for the inexperienced.
+// Please use the references to gain more information.
+static void InvMixColumns(state_t* state)
+{
+  int i;
+  uint8_t a, b, c, d;
+  for (i = 0; i < 4; ++i)
+  { 
+    a = (*state)[i][0];
+    b = (*state)[i][1];
+    c = (*state)[i][2];
+    d = (*state)[i][3];
+
+    (*state)[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
+    (*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
+    (*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
+    (*state)[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e);
+  }
+}
+
+
+// The SubBytes Function Substitutes the values in the
+// state matrix with values in an S-box.
+static void InvSubBytes(state_t* state)
+{
+  uint8_t i, j;
+  for (i = 0; i < 4; ++i)
+  {
+    for (j = 0; j < 4; ++j)
+    {
+      (*state)[j][i] = getSBoxInvert((*state)[j][i]);
+    }
+  }
+}
+
+static void InvShiftRows(state_t* state)
+{
+  uint8_t temp;
+
+  // Rotate first row 1 columns to right  
+  temp = (*state)[3][1];
+  (*state)[3][1] = (*state)[2][1];
+  (*state)[2][1] = (*state)[1][1];
+  (*state)[1][1] = (*state)[0][1];
+  (*state)[0][1] = temp;
+
+  // Rotate second row 2 columns to right 
+  temp = (*state)[0][2];
+  (*state)[0][2] = (*state)[2][2];
+  (*state)[2][2] = temp;
+
+  temp = (*state)[1][2];
+  (*state)[1][2] = (*state)[3][2];
+  (*state)[3][2] = temp;
+
+  // Rotate third row 3 columns to right
+  temp = (*state)[0][3];
+  (*state)[0][3] = (*state)[1][3];
+  (*state)[1][3] = (*state)[2][3];
+  (*state)[2][3] = (*state)[3][3];
+  (*state)[3][3] = temp;
+}
+#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
+
+// Cipher is the main function that encrypts the PlainText.
+static void Cipher(state_t* state, const uint8_t* RoundKey)
+{
+  uint8_t round = 0;
+
+  // Add the First round key to the state before starting the rounds.
+  AddRoundKey(0, state, RoundKey);
+
+  // There will be Nr rounds.
+  // The first Nr-1 rounds are identical.
+  // These Nr rounds are executed in the loop below.
+  // Last one without MixColumns()
+  for (round = 1; ; ++round)
+  {
+    SubBytes(state);
+    ShiftRows(state);
+    if (round == Nr) {
+      break;
+    }
+    MixColumns(state);
+    AddRoundKey(round, state, RoundKey);
+  }
+  // Add round key to last round
+  AddRoundKey(Nr, state, RoundKey);
+}
+
+#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
+static void InvCipher(state_t* state, const uint8_t* RoundKey)
+{
+  uint8_t round = 0;
+
+  // Add the First round key to the state before starting the rounds.
+  AddRoundKey(Nr, state, RoundKey);
+
+  // There will be Nr rounds.
+  // The first Nr-1 rounds are identical.
+  // These Nr rounds are executed in the loop below.
+  // Last one without InvMixColumn()
+  for (round = (Nr - 1); ; --round)
+  {
+    InvShiftRows(state);
+    InvSubBytes(state);
+    AddRoundKey(round, state, RoundKey);
+    if (round == 0) {
+      break;
+    }
+    InvMixColumns(state);
+  }
+
+}
+#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
+
+/*****************************************************************************/
+/* Public functions:                                                         */
+/*****************************************************************************/
+#if defined(ECB) && (ECB == 1)
+
+
+void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf)
+{
+  // The next function call encrypts the PlainText with the Key using AES algorithm.
+  Cipher((state_t*)buf, ctx->RoundKey);
+}
+
+void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf)
+{
+  // The next function call decrypts the PlainText with the Key using AES algorithm.
+  InvCipher((state_t*)buf, ctx->RoundKey);
+}
+
+
+#endif // #if defined(ECB) && (ECB == 1)
+
+
+
+
+
+#if defined(CBC) && (CBC == 1)
+
+
+static void XorWithIv(uint8_t* buf, const uint8_t* Iv)
+{
+  uint8_t i;
+  for (i = 0; i < AES_BLOCKLEN; ++i) // The block in AES is always 128bit no matter the key size
+  {
+    buf[i] ^= Iv[i];
+  }
+}
+
+void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t* buf, size_t length)
+{
+  size_t i;
+  uint8_t *Iv = ctx->Iv;
+  for (i = 0; i < length; i += AES_BLOCKLEN)
+  {
+    XorWithIv(buf, Iv);
+    Cipher((state_t*)buf, ctx->RoundKey);
+    Iv = buf;
+    buf += AES_BLOCKLEN;
+  }
+  /* store Iv in ctx for next call */
+  memcpy(ctx->Iv, Iv, AES_BLOCKLEN);
+}
+
+void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length)
+{
+  size_t i;
+  uint8_t storeNextIv[AES_BLOCKLEN];
+  for (i = 0; i < length; i += AES_BLOCKLEN)
+  {
+    memcpy(storeNextIv, buf, AES_BLOCKLEN);
+    InvCipher((state_t*)buf, ctx->RoundKey);
+    XorWithIv(buf, ctx->Iv);
+    memcpy(ctx->Iv, storeNextIv, AES_BLOCKLEN);
+    buf += AES_BLOCKLEN;
+  }
+
+}
+
+#endif // #if defined(CBC) && (CBC == 1)
+
+
+
+#if defined(CTR) && (CTR == 1)
+
+/* Symmetrical operation: same function for encrypting as for decrypting. Note any IV/nonce should never be reused with the same key */
+void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length)
+{
+  uint8_t buffer[AES_BLOCKLEN];
+  
+  size_t i;
+  int bi;
+  for (i = 0, bi = AES_BLOCKLEN; i < length; ++i, ++bi)
+  {
+    if (bi == AES_BLOCKLEN) /* we need to regen xor compliment in buffer */
+    {
+      
+      memcpy(buffer, ctx->Iv, AES_BLOCKLEN);
+      Cipher((state_t*)buffer,ctx->RoundKey);
+
+      /* Increment Iv and handle overflow */
+      for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi)
+      {
+	/* inc will overflow */
+        if (ctx->Iv[bi] == 255)
+	{
+          ctx->Iv[bi] = 0;
+          continue;
+        } 
+        ctx->Iv[bi] += 1;
+        break;   
+      }
+      bi = 0;
+    }
+
+    buf[i] = (buf[i] ^ buffer[bi]);
+  }
+}
+
+#endif // #if defined(CTR) && (CTR == 1)

components/spotify/cspot/bell/main/utilities/include/BellLogger.h

@@ -0,0 +1,120 @@
+#ifndef BELL_LOGGER_H
+#define BELL_LOGGER_H
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include <string>
+#include <memory>
+
+namespace bell
+{
+
+    class AbstractLogger
+    {
+    public:
+        bool enableSubmodule = false;
+        virtual void debug(std::string filename, int line, std::string submodule, const char *format, ...) = 0;
+        virtual void error(std::string filename, int line, std::string submodule, const char *format, ...) = 0;
+        virtual void info(std::string filename, int line, std::string submodule, const char *format, ...) = 0;
+    };
+
+    extern bell::AbstractLogger* bellGlobalLogger;
+    class BellLogger : public bell::AbstractLogger
+    {
+    public:
+        // static bool enableColors = true;
+        void debug(std::string filename, int line, std::string submodule, const char *format, ...)
+        {
+
+            printf(colorRed);
+            printf("D ");
+            if (enableSubmodule) {
+                printf(colorReset);
+                printf("[%s] ", submodule.c_str());
+            }
+            printFilename(filename);
+            printf(":%d: ", line);
+            va_list args;
+            va_start(args, format);
+            vprintf(format, args);
+            va_end(args);
+            printf("\n");
+        };
+
+        void error(std::string filename, int line, std::string submodule, const char *format, ...)
+        {
+
+            printf(colorRed);
+            printf("E ");
+            if (enableSubmodule) {
+                printf(colorReset);
+                printf("[%s] ", submodule.c_str());
+            }
+            printFilename(filename);
+            printf(":%d: ", line);
+            printf(colorRed);
+            va_list args;
+            va_start(args, format);
+            vprintf(format, args);
+            va_end(args);
+            printf("\n");
+        };
+
+        void info(std::string filename, int line, std::string submodule, const char *format, ...)
+        {
+
+            printf(colorBlue);
+            printf("I ");
+            if (enableSubmodule) {
+                printf(colorReset);
+                printf("[%s] ", submodule.c_str());
+            }
+            printFilename(filename);
+            printf(":%d: ", line);
+            printf(colorReset);
+            va_list args;
+            va_start(args, format);
+            vprintf(format, args);
+            va_end(args);
+            printf("\n");
+        };
+
+        void printFilename(std::string filename)
+        {
+#ifdef _WIN32
+            std::string basenameStr(filename.substr(filename.rfind("\\") + 1));
+#else
+            std::string basenameStr(filename.substr(filename.rfind("/") + 1));
+#endif
+            unsigned long hash = 5381;
+            for (char const &c : basenameStr)
+            {
+                hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
+            }
+
+            printf("\033[0;%dm", allColors[hash % NColors]);
+
+            printf("%s", basenameStr.c_str());
+            printf(colorReset);
+        }
+
+    private:
+        static constexpr const char *colorReset = "\033[0m";
+        static constexpr const char *colorRed = "\033[0;31m";
+        static constexpr const char *colorBlue = "\033[0;34m";
+        static constexpr const int NColors = 15;
+        static constexpr int allColors[NColors] = {31, 32, 33, 34, 35, 36, 37, 90, 91, 92, 93, 94, 95, 96, 97};
+    };
+
+    void setDefaultLogger();
+    void enableSubmoduleLogging();
+}
+
+#define BELL_LOG(type, ...)                                      \
+    do                                                            \
+    {                                                             \
+        bell::bellGlobalLogger->type(__FILE__, __LINE__, __VA_ARGS__); \
+    } while (0)
+
+#endif

components/spotify/cspot/bell/main/utilities/include/BellTask.h

@@ -0,0 +1,123 @@
+#ifndef BELL_TASK_H
+#define BELL_TASK_H
+
+#include <string>
+
+#ifdef ESP_PLATFORM
+#include <esp_pthread.h>
+#include <esp_task.h>
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
+#include <freertos/timers.h>
+#elif _WIN32
+#include <winsock2.h>
+#else
+#include <pthread.h>
+#endif
+
+#include <string>
+#include <iostream>
+
+namespace bell {
+class Task {
+ public:
+  std::string TASK;
+  int stackSize, core;
+  bool runOnPSRAM;
+  Task(std::string taskName, int stackSize, int priority, int core,
+       bool runOnPSRAM = true) {
+    this->TASK = taskName;
+    this->stackSize = stackSize;
+    this->core = core;
+    this->runOnPSRAM = runOnPSRAM;
+#ifdef ESP_PLATFORM
+    this->xStack = NULL;
+    this->priority = CONFIG_ESP32_PTHREAD_TASK_PRIO_DEFAULT + priority;
+    if (this->priority <= ESP_TASK_PRIO_MIN)
+      this->priority = ESP_TASK_PRIO_MIN + 1;
+    if (runOnPSRAM) {
+      this->xStack = (StackType_t*)heap_caps_malloc(
+          this->stackSize, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
+    }
+#endif
+  }
+  virtual ~Task() {
+#ifdef ESP_PLATFORM
+    if (xStack)
+      heap_caps_free(xStack);
+#endif
+  }
+
+  bool startTask() {
+#ifdef ESP_PLATFORM
+    if (runOnPSRAM) {
+      xTaskBuffer = (StaticTask_t*)heap_caps_malloc(
+          sizeof(StaticTask_t), MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT);
+      return (xTaskCreateStaticPinnedToCore(
+                  taskEntryFuncPSRAM, this->TASK.c_str(), this->stackSize, this,
+                  this->priority, xStack, xTaskBuffer, this->core) != NULL);
+    } else {
+      printf("task on internal %s", this->TASK.c_str());
+      esp_pthread_cfg_t cfg = esp_pthread_get_default_config();
+      cfg.stack_size = stackSize;
+      cfg.inherit_cfg = true;
+      cfg.thread_name = this->TASK.c_str();
+      cfg.pin_to_core = core;
+      cfg.prio = this->priority;
+      esp_pthread_set_cfg(&cfg);
+    }
+#endif
+#if _WIN32
+    thread = CreateThread(NULL, stackSize,
+                          (LPTHREAD_START_ROUTINE)taskEntryFunc, this, 0, NULL);
+    return thread != NULL;
+#else
+    return (pthread_create(&thread, NULL, taskEntryFunc, this) == 0);
+#endif
+  }
+
+ protected:
+  virtual void runTask() = 0;
+
+ private:
+#if _WIN32
+  HANDLE thread;
+#else
+  pthread_t thread;
+#endif
+#ifdef ESP_PLATFORM
+  int priority;
+  StaticTask_t* xTaskBuffer;
+  StackType_t* xStack;
+
+  static void taskEntryFuncPSRAM(void* This) {
+    Task* self = (Task*)This;
+    self->runTask();
+
+    // TCB are cleanup in IDLE task, so give it some time
+    TimerHandle_t timer =
+        xTimerCreate("cleanup", pdMS_TO_TICKS(5000), pdFALSE, self->xTaskBuffer,
+                     [](TimerHandle_t xTimer) {
+                       heap_caps_free(pvTimerGetTimerID(xTimer));
+                       xTimerDelete(xTimer, portMAX_DELAY);
+                     });
+    xTimerStart(timer, portMAX_DELAY);
+
+    vTaskDelete(NULL);
+  }
+#endif
+
+  static void* taskEntryFunc(void* This) {
+    Task* self = (Task*)This;
+    self->runTask();
+#if _WIN32
+    WaitForSingleObject(self->thread, INFINITE);
+#else
+    pthread_join(self->thread, NULL);
+#endif
+    return NULL;
+  }
+};
+}  // namespace bell
+
+#endif

components/spotify/cspot/bell/main/utilities/include/BellUtils.h

@@ -0,0 +1,105 @@
+#ifndef EUPHONIUM_BELL_UTILS
+#define EUPHONIUM_BELL_UTILS
+
+#include <string.h>
+#ifdef _WIN32
+#include <WinSock2.h>
+#else
+#include <sys/time.h>
+#endif
+#include <random>
+#include <vector>
+
+#ifdef ESP_PLATFORM
+//#include "esp_mac.h"
+#include "esp_system.h"
+#endif
+
+namespace bell {
+
+std::string generateRandomUUID();
+void freeAndNull(void*& ptr);
+std::string getMacAddress();
+struct tv {
+  tv() {}
+  tv(timeval tv) : sec(tv.tv_sec), usec(tv.tv_usec){};
+  tv(int32_t _sec, int32_t _usec) : sec(_sec), usec(_usec){};
+  static tv now() {
+    tv timestampNow;
+#if _WIN32
+    static const uint64_t EPOCH = ((uint64_t)116444736000000000ULL);
+
+    SYSTEMTIME  system_time;
+    FILETIME    file_time;
+    uint64_t    time;
+
+    GetSystemTime(&system_time);
+    SystemTimeToFileTime(&system_time, &file_time);
+    time = ((uint64_t)file_time.dwLowDateTime);
+    time += ((uint64_t)file_time.dwHighDateTime) << 32;
+
+    timestampNow.sec = (long)((time - EPOCH) / 10000000L);
+    timestampNow.usec = (long)(system_time.wMilliseconds * 1000);
+#else
+    timeval t;
+    gettimeofday(&t, NULL);
+    timestampNow.sec = t.tv_sec;
+    timestampNow.usec = t.tv_usec;
+#endif
+    return timestampNow;
+  }
+  int32_t sec;
+  int32_t usec;
+
+  int64_t ms() { return (sec * (int64_t)1000) + (usec / 1000); }
+
+  tv operator+(const tv& other) const {
+    tv result(*this);
+    result.sec += other.sec;
+    result.usec += other.usec;
+    if (result.usec > 1000000) {
+      result.sec += result.usec / 1000000;
+      result.usec %= 1000000;
+    }
+    return result;
+  }
+
+  tv operator/(const int& other) const {
+    tv result(*this);
+    int64_t millis = result.ms();
+    millis = millis / other;
+    result.sec = std::floor(millis / 1000.0);
+    result.usec = (int32_t)((int64_t)(millis * 1000) % 1000000);
+    return result;
+  }
+
+  tv operator-(const tv& other) const {
+    tv result(*this);
+    result.sec -= other.sec;
+    result.usec -= other.usec;
+    while (result.usec < 0) {
+      result.sec -= 1;
+      result.usec += 1000000;
+    }
+    return result;
+  }
+};
+}  // namespace bell
+
+#ifdef ESP_PLATFORM
+#include <freertos/FreeRTOS.h>
+
+#define BELL_SLEEP_MS(ms) vTaskDelay(ms / portTICK_PERIOD_MS)
+#define BELL_YIELD() taskYIELD()
+
+#elif defined(_WIN32)
+#define BELL_SLEEP_MS(ms) Sleep(ms)
+#define BELL_YIELD() ;
+#else
+#include <unistd.h>
+
+#define BELL_SLEEP_MS(ms) usleep(ms * 1000)
+#define BELL_YIELD() ;
+
+#endif
+#endif

components/spotify/cspot/bell/main/utilities/include/Crypto.h

@@ -0,0 +1,83 @@
+#ifndef BELL_CRYPTO_H
+#define BELL_CRYPTO_H
+
+#define Crypto CryptoMbedTLS
+
+#include <vector>
+#include <string>
+#include <memory>
+#include <stdexcept>
+
+extern "C" {
+#include "aes.h"
+}
+#include <mbedtls/base64.h>
+#include <mbedtls/bignum.h>
+#include <mbedtls/md.h>
+#include <mbedtls/aes.h>
+#include <mbedtls/pkcs5.h>
+#include <mbedtls/entropy.h>
+#include <mbedtls/ctr_drbg.h>
+
+
+#define DH_KEY_SIZE 96
+
+static unsigned char DHPrime[] = {
+    /* Well-known Group 1, 768-bit prime */
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc9,
+    0x0f, 0xda, 0xa2, 0x21, 0x68, 0xc2, 0x34, 0xc4, 0xc6,
+    0x62, 0x8b, 0x80, 0xdc, 0x1c, 0xd1, 0x29, 0x02, 0x4e,
+    0x08, 0x8a, 0x67, 0xcc, 0x74, 0x02, 0x0b, 0xbe, 0xa6,
+    0x3b, 0x13, 0x9b, 0x22, 0x51, 0x4a, 0x08, 0x79, 0x8e,
+    0x34, 0x04, 0xdd, 0xef, 0x95, 0x19, 0xb3, 0xcd, 0x3a,
+    0x43, 0x1b, 0x30, 0x2b, 0x0a, 0x6d, 0xf2, 0x5f, 0x14,
+    0x37, 0x4f, 0xe1, 0x35, 0x6d, 0x6d, 0x51, 0xc2, 0x45,
+    0xe4, 0x85, 0xb5, 0x76, 0x62, 0x5e, 0x7e, 0xc6, 0xf4,
+    0x4c, 0x42, 0xe9, 0xa6, 0x3a, 0x36, 0x20, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+};
+
+static unsigned char DHGenerator[1] = {2};
+
+class CryptoMbedTLS {
+private:
+    mbedtls_md_context_t sha1Context;
+    mbedtls_aes_context aesCtx;
+    bool aesCtxInitialized = false;
+public:
+    CryptoMbedTLS();
+    ~CryptoMbedTLS();
+    // Base64
+    std::vector<uint8_t> base64Decode(const std::string& data);
+    std::string base64Encode(const std::vector<uint8_t>& data);
+
+    // Sha1
+    void sha1Init();
+    void sha1Update(const std::string& s);
+    void sha1Update(const std::vector<uint8_t>& vec);
+    std::string sha1Final();
+    std::vector<uint8_t> sha1FinalBytes();
+
+    // HMAC SHA1
+    std::vector<uint8_t> sha1HMAC(const std::vector<uint8_t>& inputKey, const std::vector<uint8_t>& message);
+
+    // AES CTR
+    void aesCTRXcrypt(const std::vector<uint8_t>& key, std::vector<uint8_t>& iv, uint8_t* data, size_t nbytes);
+    
+    // AES ECB
+    void aesECBdecrypt(const std::vector<uint8_t>& key, std::vector<uint8_t>& data);
+
+    // Diffie Hellman
+    std::vector<uint8_t> publicKey;
+    std::vector<uint8_t> privateKey;
+    void dhInit();
+    std::vector<uint8_t> dhCalculateShared(const std::vector<uint8_t>& remoteKey);
+
+    // PBKDF2
+    std::vector<uint8_t> pbkdf2HmacSha1(const std::vector<uint8_t>& password, const std::vector<uint8_t>& salt, int iterations, int digestSize);
+
+    // Random stuff
+    std::vector<uint8_t> generateVectorWithRandomData(size_t length);
+};
+
+#endif

components/spotify/cspot/bell/main/utilities/include/NanoPBHelper.h

@@ -0,0 +1,47 @@
+#pragma once
+
+#include <vector>
+#include "pb_encode.h"
+#include "pb_decode.h"
+#include <string>
+
+std::vector<uint8_t> pbEncode(const pb_msgdesc_t *fields, const void *src_struct);
+
+pb_bytes_array_t* vectorToPbArray(const std::vector<uint8_t>& vectorToPack);
+
+void packString(char* &dst, std::string stringToPack);
+
+std::vector<uint8_t> pbArrayToVector(pb_bytes_array_t* pbArray);
+
+template <typename T>
+T pbDecode(const pb_msgdesc_t *fields, std::vector<uint8_t> &data)
+{
+
+    T result = {};
+    // Create stream
+    pb_istream_t stream = pb_istream_from_buffer(&data[0], data.size());
+    
+    // Decode the message
+    if (pb_decode(&stream, fields, &result) == false) {
+        printf("Decode failed: %s\n", PB_GET_ERROR(&stream));
+    }
+    return result;
+}
+
+template <typename T>
+void pbDecode(T &result, const pb_msgdesc_t *fields, std::vector<uint8_t> &data)
+{
+    // Create stream
+    pb_istream_t stream = pb_istream_from_buffer(&data[0], data.size());
+    
+    // Decode the message
+    if (pb_decode(&stream, fields, &result) == false) {
+        printf("Decode failed: %s\n", PB_GET_ERROR(&stream));
+    }
+}
+
+void pbPutString(const std::string &stringToPack, char* dst);
+void pbPutCharArray(const char * stringToPack, char* dst);
+void pbPutBytes(const std::vector<uint8_t> &data, pb_bytes_array_t &dst);
+
+const char* pb_encode_to_string(const pb_msgdesc_t *fields, const void *data);

components/spotify/cspot/bell/main/utilities/include/Queue.h

@@ -0,0 +1,117 @@
+#ifndef BELL_QUEUE_H
+#define BELL_QUEUE_H
+
+#include <queue>
+#include <atomic>
+#include <condition_variable>
+#include <atomic>
+
+namespace bell
+{
+    template <typename dataType>
+    class Queue
+    {
+    private:
+        /// Queue
+        std::queue<dataType> m_queue;
+        /// Mutex to controll multiple access
+        mutable std::mutex m_mutex;
+        /// Conditional variable used to fire event
+        std::condition_variable m_cv;
+        /// Atomic variable used to terminate immediately wpop and wtpop functions
+        std::atomic<bool> m_forceExit = false;
+
+    public:
+        /// <summary> Add a new element in the queue. </summary>
+        /// <param name="data"> New element. </param>
+        void push(dataType const &data)
+        {
+            m_forceExit.store(false);
+            std::unique_lock<std::mutex> lk(m_mutex);
+            m_queue.push(data);
+            lk.unlock();
+            m_cv.notify_one();
+        }
+        /// <summary> Check queue empty. </summary>
+        /// <returns> True if the queue is empty. </returns>
+        bool isEmpty() const
+        {
+            std::unique_lock<std::mutex> lk(m_mutex);
+            return m_queue.empty();
+        }
+        /// <summary> Pop element from queue. </summary>
+        /// <param name="popped_value"> [in,out] Element. </param>
+        /// <returns> false if the queue is empty. </returns>
+        bool pop(dataType &popped_value)
+        {
+            std::unique_lock<std::mutex> lk(m_mutex);
+            if (m_queue.empty())
+            {
+                return false;
+            }
+            else
+            {
+                popped_value = m_queue.front();
+                m_queue.pop();
+                return true;
+            }
+        }
+        /// <summary> Wait and pop an element in the queue. </summary>
+        /// <param name="popped_value"> [in,out] Element. </param>
+        ///  <returns> False for forced exit. </returns>
+        bool wpop(dataType &popped_value)
+        {
+            std::unique_lock<std::mutex> lk(m_mutex);
+            m_cv.wait(lk, [&]() -> bool
+                      { return !m_queue.empty() || m_forceExit.load(); });
+            if (m_forceExit.load())
+                return false;
+            popped_value = m_queue.front();
+            m_queue.pop();
+            return true;
+        }
+        /// <summary> Timed wait and pop an element in the queue. </summary>
+        /// <param name="popped_value"> [in,out] Element. </param>
+        /// <param name="milliseconds"> [in] Wait time. </param>
+        ///  <returns> False for timeout or forced exit. </returns>
+        bool wtpop(dataType &popped_value, long milliseconds = 1000)
+        {
+            std::unique_lock<std::mutex> lk(m_mutex);
+            m_cv.wait_for(lk, std::chrono::milliseconds(milliseconds), [&]() -> bool
+                          { return !m_queue.empty() || m_forceExit.load(); });
+            if (m_forceExit.load())
+                return false;
+            if (m_queue.empty())
+                return false;
+            popped_value = m_queue.front();
+            m_queue.pop();
+            return true;
+        }
+        /// <summary> Queue size. </summary>
+        int size()
+        {
+            std::unique_lock<std::mutex> lk(m_mutex);
+            return static_cast<int>(m_queue.size());
+        }
+        /// <summary> Free the queue and force stop. </summary>
+        void clear()
+        {
+            m_forceExit.store(true);
+            std::unique_lock<std::mutex> lk(m_mutex);
+            while (!m_queue.empty())
+            {
+                //delete m_queue.front();
+                m_queue.pop();
+            }
+            lk.unlock();
+            m_cv.notify_one();
+        }
+        /// <summary> Check queue in forced exit state. </summary>
+        bool isExit() const
+        {
+            return m_forceExit.load();
+        }
+    };
+}
+
+#endif

components/spotify/cspot/bell/main/utilities/include/TimeDefs.h

@@ -0,0 +1,8 @@
+//
+// Created by Filip Grzywok on 28/02/2022.
+//
+
+#ifndef EUPHONIUMCLI_TIMEDEFS_H
+#define EUPHONIUMCLI_TIMEDEFS_H
+
+#endif // EUPHONIUMCLI_TIMEDEFS_H

components/spotify/cspot/bell/main/utilities/include/aes.h

@@ -0,0 +1,91 @@
+#ifndef _AES_H_
+#define _AES_H_
+
+#include <stdint.h>
+#include <stddef.h>
+
+// #define the macros below to 1/0 to enable/disable the mode of operation.
+//
+// CBC enables AES encryption in CBC-mode of operation.
+// CTR enables encryption in counter-mode.
+// ECB enables the basic ECB 16-byte block algorithm. All can be enabled simultaneously.
+
+// The #ifndef-guard allows it to be configured before #include'ing or at compile time.
+#ifndef CBC
+  #define CBC 1
+#endif
+
+#ifndef ECB
+  #define ECB 1
+#endif
+
+#ifndef CTR
+  #define CTR 1
+#endif
+
+
+// #define AES128 1
+#define AES192 1
+//#define AES256 1
+
+#define AES_BLOCKLEN 16 // Block length in bytes - AES is 128b block only
+
+#if defined(AES256) && (AES256 == 1)
+    #define AES_KEYLEN 32
+    #define AES_keyExpSize 240
+#elif defined(AES192) && (AES192 == 1)
+    #define AES_KEYLEN 24
+    #define AES_keyExpSize 208
+#else
+    #define AES_KEYLEN 16   // Key length in bytes
+    #define AES_keyExpSize 176
+#endif
+
+struct AES_ctx
+{
+  uint8_t RoundKey[AES_keyExpSize];
+#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
+  uint8_t Iv[AES_BLOCKLEN];
+#endif
+};
+
+void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key);
+#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
+void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv);
+void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
+#endif
+
+#if defined(ECB) && (ECB == 1)
+// buffer size is exactly AES_BLOCKLEN bytes; 
+// you need only AES_init_ctx as IV is not used in ECB 
+// NB: ECB is considered insecure for most uses
+void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf);
+void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf);
+
+#endif // #if defined(ECB) && (ECB == !)
+
+
+#if defined(CBC) && (CBC == 1)
+// buffer size MUST be mutile of AES_BLOCKLEN;
+// Suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
+// NOTES: you need to set IV in ctx via AES_init_ctx_iv() or AES_ctx_set_iv()
+//        no IV should ever be reused with the same key 
+void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
+void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
+
+#endif // #if defined(CBC) && (CBC == 1)
+
+
+#if defined(CTR) && (CTR == 1)
+
+// Same function for encrypting as for decrypting. 
+// IV is incremented for every block, and used after encryption as XOR-compliment for output
+// Suggesting https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
+// NOTES: you need to set IV in ctx with AES_init_ctx_iv() or AES_ctx_set_iv()
+//        no IV should ever be reused with the same key 
+void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
+
+#endif // #if defined(CTR) && (CTR == 1)
+
+
+#endif // _AES_H_

components/spotify/cspot/bell/main/utilities/include/esp_platform.h

@@ -0,0 +1,4 @@
+#ifdef __XTENSA__
+#include <xtensa/config/core-isa.h>
+#include <xtensa/config/core-matmap.h>
+#endif