Files
squeezelite-esp32/components/spotify/cspot/bell/main/utilities/Crypto.cpp
2023-10-02 19:06:59 -07:00

240 lines
7.3 KiB
C++

#include "Crypto.h"
#include <mbedtls/base64.h> // for mbedtls_base64_encode, mbedtls_base64_...
#include <mbedtls/bignum.h> // for mbedtls_mpi_free, mbedtls_mpi_init
#include <mbedtls/ctr_drbg.h> // for mbedtls_ctr_drbg_free, mbedtls_ctr_drb...
#include <mbedtls/entropy.h> // for mbedtls_entropy_free, mbedtls_entropy_...
#include <mbedtls/pkcs5.h> // for mbedtls_pkcs5_pbkdf2_hmac
#include <cstdint> // for uint8_t
#include <stdexcept> // for runtime_error
extern "C" {
#include "aes.h" // for AES_ECB_decrypt, AES_init_ctx, AES_ctx
}
static unsigned char DHGenerator[1] = {2};
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);
#if MBEDTLS_VERSION_NUMBER < 0x03030000
// 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);
#else
mbedtls_pkcs5_pbkdf2_hmac_ext(MBEDTLS_MD_SHA1, password.data(),
password.size(), salt.data(), salt.size(),
iterations, digestSize, digest.data());
#endif
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;
}