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#include "ec_keys.hh"
#include "loggers.hh" // To be remove to build a security shared library
ec_keys::ec_keys(const ec_elliptic_curves p_elliptic_curve): _elliptic_curve(p_elliptic_curve), _encryption_algotithm(encryption_algotithm::aes_128_ccm), _ec_key(nullptr), _ec_group(nullptr), _bn_ctx(nullptr), _pri_key(), _pub_key_x(), _pub_key_y(), _eph_key(), _enc_key_x(), _enc_key_y(), _nonce(), _tag() {
loggers::get_instance().log(">>> ec_keys::ec_keys: %d", static_cast<int>(p_elliptic_curve));
const int result = init();
if (result == -1) {
loggers::get_instance().error("ec_keys::ec_keys: Unsupported elliptic_curve %d", _elliptic_curve);
}
ec_keys::ec_keys(const ec_elliptic_curves p_elliptic_curve, const std::vector<unsigned char>& p_private_key): _elliptic_curve(p_elliptic_curve), _encryption_algotithm(encryption_algotithm::aes_128_ccm), _ec_key(nullptr), _ec_group(nullptr), _bn_ctx(nullptr), _pri_key(p_private_key), _pub_key_x(), _pub_key_y(), _eph_key(), _enc_key_x(), _enc_key_y(), _nonce(), _tag() {
loggers::get_instance().log(">>> ec_keys::ec_keys (1): %d", static_cast<int>(p_elliptic_curve));
// Sanity checks
if ((_elliptic_curve == ec_elliptic_curves::nist_p_256) || (_elliptic_curve == ec_elliptic_curves::brainpool_p_256_r1)) {
if (p_private_key.size() != 32) {
loggers::get_instance().error("ec_keys::ec_keys: Invalid public keys size");
}
} else if (_elliptic_curve == ec_elliptic_curves::brainpool_p_384_r1) {
if ((p_private_key.size() != 48)) {
loggers::get_instance().error("ec_keys::ec_keys: Invalid public keys size");
}
}
int result = init();
if (result == -1) {
loggers::get_instance().error("ec_keys::ec_keys: Unsupported elliptic_curve %d", _elliptic_curve);
}
::EC_KEY_set_conv_form(_ec_key, POINT_CONVERSION_COMPRESSED);
// Build private key
BIGNUM p;
::BN_init(&p);
::BN_bin2bn(_pri_key.data(), _pri_key.size(), &p);
// Build public keys
EC_POINT* ec_point = ::EC_POINT_new(_ec_group);
::EC_POINT_mul(_ec_group, ec_point, &p, NULL, NULL, _bn_ctx);
// Set private key
::EC_KEY_set_private_key(_ec_key, &p);
if (::EC_KEY_check_key(_ec_key) != 0) {
loggers::get_instance().error("ec_keys::ec_keys (1): Invalid private key");
}
// Private key is correct, set public keys
::EC_KEY_set_public_key(_ec_key, ec_point);
BIGNUM xy;
::BN_init(&xy);
::EC_POINT_point2bn(_ec_group, ec_point, POINT_CONVERSION_COMPRESSED, &xy, _bn_ctx);
std::vector<unsigned char> v(BN_num_bytes(&xy));
_pub_key_x.resize(l);
std::copy(v.cbegin(), v.cbegin() + l - 1, _pub_key_x.begin());
_pub_key_y.resize(l);
std::copy(v.cbegin() + l, v.cend(), _pub_key_y.begin());
::EC_POINT_free(ec_point);
} // End of constructor
ec_keys::ec_keys(const ec_elliptic_curves p_elliptic_curve, const std::vector<unsigned char>& p_public_key_x, const std::vector<unsigned char>& p_public_key_y): _elliptic_curve(p_elliptic_curve), _encryption_algotithm(encryption_algotithm::aes_128_ccm), _ec_key(nullptr), _ec_group(nullptr), _bn_ctx(nullptr), _pri_key(), _pub_key_x(p_public_key_x), _pub_key_y(p_public_key_y), _eph_key(), _enc_key_x(), _enc_key_y(), _nonce(), _tag() {
loggers::get_instance().log(">>> ec_keys::ec_keys (2): %d", static_cast<int>(p_elliptic_curve));
// Sanity checks
if ((_elliptic_curve == ec_elliptic_curves::nist_p_256) || (_elliptic_curve == ec_elliptic_curves::brainpool_p_256_r1)) {
if ((p_public_key_x.size() != 32) || (p_public_key_y.size() != 32)) {
loggers::get_instance().error("ec_keys::ec_keys: Invalid public keys size");
}
} else if (_elliptic_curve == ec_elliptic_curves::brainpool_p_384_r1) {
if ((p_public_key_x.size() != 48) || (p_public_key_y.size() != 48)) {
loggers::get_instance().error("ec_keys::ec_keys: Invalid public keys size");
}
}
int result = init();
if (result == -1) {
loggers::get_instance().error("ec_keys::ec_keys: Unsupported elliptic_curve %d", _elliptic_curve);
}
::EC_KEY_set_conv_form(_ec_key, POINT_CONVERSION_COMPRESSED);
// Set public key
BIGNUM x;
::BN_init(&x);
::BN_bin2bn(_pub_key_x.data(), _pub_key_x.size(), &x);
::BN_bin2bn(_pub_key_y.data(), _pub_key_y.size(), &y);
EC_POINT* ec_point = ::EC_POINT_new(_ec_group);
result = 0;
switch (_elliptic_curve) {
case ec_elliptic_curves::nist_p_256: // Use primary
// No break;
case ec_elliptic_curves::brainpool_p_256_r1:
// No break;
case ec_elliptic_curves::brainpool_p_384_r1:
result = ::EC_POINT_set_affine_coordinates_GFp(_ec_group, ec_point, &x, &y, _bn_ctx); // Use primary elliptic curve
break;
result = ::EC_POINT_set_affine_coordinates_GF2m(_ec_group, ec_point, &x, &y, _bn_ctx);
} // End of 'switch' statement
if (result == 0) {
loggers::get_instance().error("ec_keys::ec_keys (1): Failed to get coordinates");
}
::EC_KEY_set_public_key(_ec_key, ec_point);
::EC_POINT_free(ec_point);
} // End of constructor
ec_keys::~ec_keys() {
loggers::get_instance().log(">>> ec_keys::~ec_keys");
if(_ec_key != nullptr) {
::EC_KEY_free(_ec_key);
}
loggers::get_instance().log("<<< ec_keys::~ec_keys");
} // End of Destructor
int ec_keys::generate() {
loggers::get_instance().log(">>> ec_keys::generate");
// Sanity check
if (!::EC_KEY_generate_key(_ec_key)) { // Generate the private and public keys
loggers::get_instance().error("ec_keys::generate: Failed to generate private/public keys");
const EC_POINT* ec_point = EC_KEY_get0_public_key(_ec_key);
int result = 0;
switch (_elliptic_curve) {
case ec_elliptic_curves::nist_p_256: // Use primary
// No break;
case ec_elliptic_curves::brainpool_p_256_r1:
// No break;
case ec_elliptic_curves::brainpool_p_384_r1:
result = ::EC_POINT_get_affine_coordinates_GFp(_ec_group, ec_point, &x, &y, _bn_ctx); // Use primer on elliptic curve
break;
result = ::EC_POINT_get_affine_coordinates_GF2m(_ec_group, ec_point, &x, &y, _bn_ctx);
} // End of 'switch' statement
if (result == 0) {
loggers::get_instance().error("ec_keys::generate: Failed to get coordinates");
}
const BIGNUM* p = ::EC_KEY_get0_private_key(_ec_key);
_pri_key.resize(BN_num_bytes(p));
::BN_bn2bin(p, _pri_key.data());
_pub_key_x.resize(BN_num_bytes(&x));
::BN_bn2bin(&x, _pub_key_x.data());
_pub_key_y.resize(BN_num_bytes(&y));
::BN_bn2bin(&y, _pub_key_y.data());
// Compressed
int len = ::EC_POINT_point2oct(_ec_group, ec_point, POINT_CONVERSION_COMPRESSED, NULL, 0, _bn_ctx);
std::vector<unsigned char> cy;
cy.resize(len);
::EC_POINT_point2oct(_ec_group, ec_point, POINT_CONVERSION_COMPRESSED, (unsigned char *)cy.data(), len, _bn_ctx);
// TODO Create a compressed _pub_key_compressed_y
//_pub_key_compressed_y.resize(BN_num_bytes(&compressed_y));
//::BN_bn2bin(&compressed_y, _pub_key_compressed_y.data());
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/*int ec_keys::generate_ephemeral_key(const std::vector<unsigned char>& p_public_key_x, const std::vector<unsigned char>& p_public_key_y) { // TODO Move it into encrypt
printf(">>> ec_keys::generate_ephemeral_key (1)");
// Sanity checks
if ((_pub_key_x.size() != 0) || (_pub_key_y.size() != 0)) {
printf("ec_keys::generate_ephemeral_key: Constrictor format #1 shall be used");
return -1;
}
::EC_KEY_generate_key(_ec_key);
// Set buffers size
int len = (EC_GROUP_get_degree(_ec_group) + 7) / 8;
_eph_key.resize(len);
printf("ec_keys::generate_ephemeral_key: ephemeral_ec_key_len=%d\n", _eph_key.size());
// Convert the public keys (X,Y) into EC_POINT data structure
EC_POINT *ec_point = nullptr;
bin_to_ec_point(p_public_key_x, p_public_key_y, &ec_point);
// Generate the shared symmetric key
int result = ::ECDH_compute_key(_eph_key.data(), _eph_key.size(), ec_point, _ec_key, NULL);
if (result == -1) {
::EC_POINT_free(ec_point);
return -1;
}
::EC_POINT_free(ec_point);
// Write the ephemeral key's public key to the output buffer
std::vector<unsigned char> enc_key;
public_key_to_bin(enc_key);
dump_hexa("encryption_key: ", enc_key.data(), enc_key.size());
// Extract X-coordinate and Y-coordinate
_enc_key_x.assign(1 + enc_key.cbegin(), 1 + len + enc_key.cbegin());
_enc_key_y.assign(1 + len + enc_key.cbegin(), enc_key.cend());
return 0;
}*/
/*int ec_keys::generate_ephemeral_key(encryption_algotithm p_enc_algorithm, const std::vector<unsigned char>& p_public_enc_key_x, const std::vector<unsigned char>& p_public_enc_key_y, const std::vector<unsigned char>& p_nonce, const std::vector<unsigned char>& p_tag) { // TODO Change it into ctor
printf(">>> ec_keys::generate_ephemeral_key (2)");
// Sanity checks
if ((_pub_key_x.size() == 0) || (_pub_key_y.size() == 0)) {
printf("ec_keys::generate_ephemeral_key: Constrictor format #2 shall be used");
return -1;
}
_encryption_algotithm = p_enc_algorithm;
_nonce = p_nonce;
_tag = p_tag;
// Set buffers size
int len = (EC_GROUP_get_degree(_ec_group) + 7) / 8;
_eph_key.resize(len);
printf("ec_keys::generate_ephemeral_key: ephemeral_ec_key_len=%d\n", _eph_key.size());
// Convert the peer public encryption key to an EC point
EC_POINT *ec_point = nullptr;
bin_to_ec_point(p_public_enc_key_x, p_public_enc_key_y, &ec_point);
// Generate the shared symmetric key
int result = ::ECDH_compute_key(_eph_key.data(), _eph_key.size(), ec_point, _ec_key, NULL);
if (result == -1) {
::EC_POINT_free(ec_point);
return -1;
}
::EC_POINT_free(ec_point);
return 0;
}*/
int ec_keys::encrypt(const encryption_algotithm p_enc_algorithm, const std::vector<unsigned char>& p_public_key_x, const std::vector<unsigned char>& p_public_key_y, const std::vector<unsigned char>& p_message, std::vector<unsigned char>& p_enc_message) {
loggers::get_instance().log(">>> ec_keys::encrypt");
// Sanity checks
if ((_pub_key_x.size() != 0) || (_pub_key_y.size() != 0)) {
loggers::get_instance().error("ec_keys::encrypt: Constructor format #1 shall be used");
return -1;
}
_encryption_algotithm = p_enc_algorithm;
::EC_KEY_generate_key(_ec_key);
// Set buffers size
int len = (EC_GROUP_get_degree(_ec_group) + 7) / 8;
_eph_key.resize(len);
// Convert the public keys (X,Y) into EC_POINT data structure
EC_POINT *ec_point = nullptr;
bin_to_ec_point(p_public_key_x, p_public_key_y, &ec_point);
// Generate the shared symmetric key
int result = ::ECDH_compute_key(_eph_key.data(), _eph_key.size(), ec_point, _ec_key, NULL);
if (result == -1) {
::EC_POINT_free(ec_point);
return -1;
}
::EC_POINT_free(ec_point);
// Write the ephemeral key's public key to the output buffer
std::vector<unsigned char> enc_key;
public_key_to_bin(enc_key);
// Extract X-coordinate and Y-coordinate
_enc_key_x.assign(1 + enc_key.cbegin(), 1 + len + enc_key.cbegin());
_enc_key_y.assign(1 + len + enc_key.cbegin(), enc_key.cend());
// Initialize the context and encryption operation
EVP_CIPHER_CTX *ctx = ::EVP_CIPHER_CTX_new();
switch (_encryption_algotithm) {
case encryption_algotithm::aes_128_ccm:
::EVP_EncryptInit_ex(ctx, EVP_aes_128_ccm(), NULL, NULL, NULL);
// Allocate buffers size
_nonce.resize(12);
_tag.resize(16);
p_enc_message.resize(p_message.size());
break;
case encryption_algotithm::aes_256_ccm:
::EVP_EncryptInit_ex(ctx, EVP_aes_256_ccm(), NULL, NULL, NULL);
break;
case encryption_algotithm::aes_128_gcm:
::EVP_EncryptInit_ex(ctx, EVP_aes_128_gcm(), NULL, NULL, NULL);
break;
case encryption_algotithm::aes_256_gcm:
::EVP_EncryptInit_ex(ctx, EVP_aes_256_gcm(), NULL, NULL, NULL);
break;
} // End of 'switch' statement
// Generate _nonce
::RAND_pseudo_bytes(_nonce.data(), _nonce.size());
// Set nonce length
::EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_IVLEN, _nonce.size(), NULL);
// Set tag length
::EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_TAG, _tag.size(), NULL);
// Prime the key and nonce
::EVP_EncryptInit_ex(ctx, NULL, NULL, _eph_key.data(), _nonce.data());
// No authentication data
// Encrypt the data
::EVP_EncryptUpdate(ctx, p_enc_message.data(), &len, p_message.data(), p_message.size());
// Finalize the encryption session
::EVP_EncryptFinal_ex(ctx, p_enc_message.data() + len, &len);
// Get the authentication tag
::EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_GET_TAG, _tag.size(), _tag.data());
::EVP_CIPHER_CTX_free(ctx);
return 0;
}
int ec_keys::decrypt(const encryption_algotithm p_enc_algorithm, const std::vector<unsigned char>& p_public_enc_key_x, const std::vector<unsigned char>& p_public_enc_key_y, const std::vector<unsigned char>& p_nonce, const std::vector<unsigned char>& p_tag, const std::vector<unsigned char>& p_enc_message, std::vector<unsigned char>& p_message) {
loggers::get_instance().log(">>> ec_keys::decrypt");
// Sanity checks
if ((_pub_key_x.size() == 0) || (_pub_key_y.size() == 0)) {
loggers::get_instance().error("ec_keys::decrypt: Constrictor format #2 shall be used");
return -1;
}
_encryption_algotithm = p_enc_algorithm;
_nonce = p_nonce;
_tag = p_tag;
// Set buffers size
int len = (EC_GROUP_get_degree(_ec_group) + 7) / 8;
_eph_key.resize(len);
// Convert the peer public encryption key to an EC point
EC_POINT *ec_point = nullptr;
bin_to_ec_point(p_public_enc_key_x, p_public_enc_key_y, &ec_point);
// Generate the shared symmetric key
int result = ::ECDH_compute_key(_eph_key.data(), _eph_key.size(), ec_point, _ec_key, NULL);
if (result == -1) {
::EC_POINT_free(ec_point);
return -1;
}
::EC_POINT_free(ec_point);
// Initialize the context and decryption operation
EVP_CIPHER_CTX *ctx = ::EVP_CIPHER_CTX_new();
switch (_encryption_algotithm) {
case encryption_algotithm::aes_128_ccm:
::EVP_DecryptInit_ex(ctx, EVP_aes_128_ccm(), NULL, NULL, NULL);
break;
case encryption_algotithm::aes_256_ccm:
::EVP_DecryptInit_ex(ctx, EVP_aes_256_ccm(), NULL, NULL, NULL);
break;
case encryption_algotithm::aes_128_gcm:
::EVP_DecryptInit_ex(ctx, EVP_aes_128_gcm(), NULL, NULL, NULL);
break;
case encryption_algotithm::aes_256_gcm:
::EVP_DecryptInit_ex(ctx, EVP_aes_256_gcm(), NULL, NULL, NULL);
break;
} // End of 'switch' statement
// Set nonce length
EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_IVLEN, _nonce.size(), NULL);
// Set expected tag value
EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_CCM_SET_TAG, _tag.size(), _tag.data());
// Specify key and IV
EVP_DecryptInit_ex(ctx, NULL, NULL, _eph_key.data(), _nonce.data());
// Decrypt plaintext, verify tag: can only be called once
p_message.resize(p_enc_message.size());
result = EVP_DecryptUpdate(ctx, p_message.data(), &len, p_enc_message.data(), p_enc_message.size());
::EVP_CIPHER_CTX_free(ctx);
return (result > 0) ? 0 : -1;
}
int ec_keys::sign(const std::vector<unsigned char>& p_data, std::vector<unsigned char>& p_r_sig, std::vector<unsigned char>& p_s_sig) {
loggers::get_instance().log(">>> ec_keys::sign");
// Sanity checks
if(_pri_key.size() == 0) { // No private key
ECDSA_SIG *signature = ::ECDSA_do_sign(p_data.data(), p_data.size(), _ec_key);
if (signature == nullptr) {
loggers::get_instance().warning("ec_keys::sign: Signature failed");
return -1;
}
loggers::get_instance().log("ec_keys::sign: succeed");
if (::ECDSA_do_verify(p_data.data(), p_data.size(), signature, _ec_key) != 1) {
loggers::get_instance().warning("ec_keys::sign: Signature not verified");
return -1;
}
p_r_sig.resize(BN_num_bytes(signature->r));
::BN_bn2bin(signature->r, p_r_sig.data());
//loggers::get_instance().log_to_hexa("ec_keys::sign: r=", p_r_sig.data(), p_r_sig.size());
p_s_sig.resize(BN_num_bytes(signature->r));
::BN_bn2bin(signature->s, p_s_sig.data());
//loggers::get_instance().log_to_hexa("ec_keys::sign: s=", p_s_sig.data(), p_s_sig.size());
::ECDSA_SIG_free(signature);
return 0;
}
int ec_keys::sign_verif(const std::vector<unsigned char>& p_data, const std::vector<unsigned char>& p_signature) {
loggers::get_instance().log(">>> ec_keys::sign_verif");
// Sanity checks
if (p_data.size() == 0) {
return false;
}
// Build the signature
BIGNUM r, s;
::BN_init(&r);
::BN_init(&s);
::BN_bin2bn(p_signature.data(), p_signature.size() / 2, &r);
::BN_bin2bn(p_signature.data() + p_signature.size() / 2, p_signature.size() / 2, &s);
ECDSA_SIG *signature = ECDSA_SIG_new();
signature->r = &r;
signature->s = &s;
int result = ::ECDSA_do_verify(p_data.data(), p_data.size(), signature, _ec_key);
::ECDSA_SIG_free(signature);
loggers::get_instance().log("ec_keys::sign_verif: %s", (result == 1) ? "succeed": "failed");
return result != 1;
}
const int ec_keys::init() {
loggers::get_instance().log(">>> ec_keys::init: %d", static_cast<int>(_elliptic_curve));
::OpenSSL_add_all_algorithms();
switch (_elliptic_curve) { // TODO Group this cde into a private method
case ec_elliptic_curves::nist_p_256: // Use the ANSI X9.62 Prime 256v1 curve
result = ::OBJ_txt2nid("prime256v1");
break;
case ec_elliptic_curves::brainpool_p_256_r1:
result = ::OBJ_txt2nid("brainpoolP256r1");
break;
case ec_elliptic_curves::brainpool_p_384_r1:
result = ::OBJ_txt2nid("brainpoolP384r1");
break;
default:
loggers::get_instance().error("ec_keys::ec_keys: Unsupported EC elliptic_curve");
} // End of 'switch' statement
if (result < 0) {
loggers::get_instance().warning("ec_keys::ec_keys: Unaible to set EC elliptic_curve");
return -1;
}
_ec_key = ::EC_KEY_new_by_curve_name(result); // Set the elliptic curve
::EC_KEY_set_asn1_flag(_ec_key, OPENSSL_EC_NAMED_CURVE); // Used to save and retrieve keys
_ec_group = ::EC_KEY_get0_group(_ec_key); // Get pointer to the EC_GROUP
_bn_ctx = ::BN_CTX_new();
return 0;
} // End of init
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int ec_keys::bin_to_ec_point(const std::vector<unsigned char>& p_public_key_x, const std::vector<unsigned char>& p_public_key_y, EC_POINT** p_ec_point) { // ec_key_public_key_bin_to_point
BIGNUM* pubk_bn;
std::vector<unsigned char> v(1, 0x04);
v.insert(v.end(), std::make_move_iterator(p_public_key_x.begin()), std::make_move_iterator(p_public_key_x.end()));
v.insert(v.end(), std::make_move_iterator(p_public_key_y.begin()), std::make_move_iterator(p_public_key_y.end()));
pubk_bn = ::BN_bin2bn(v.data(), v.size(), NULL);
*p_ec_point = ::EC_POINT_new(_ec_group);
::EC_POINT_bn2point(_ec_group, pubk_bn, *p_ec_point, _bn_ctx);
// BIO *bio_out = NULL; /* stdout */
// bio_out = BIO_new_fp(stdout, BIO_NOCLOSE);
// BIGNUM *x = BN_new();
// BIGNUM *y = BN_new();
// if (EC_POINT_get_affine_coordinates_GFp(_ec_group, *p_ec_point, x, y, NULL)) {
// BN_print_fp(stdout, x);
// putc('\n', stdout);
// BN_print_fp(stdout, y);
// putc('\n', stdout);
// }
// BN_free(x); BN_free(y);
return 0;
}
int ec_keys::public_key_to_bin(std::vector<unsigned char>& p_bin_key) { // ec_key_public_key_to_bin
const EC_GROUP *ec_group = EC_KEY_get0_group(_ec_key);
const EC_POINT *pub = EC_KEY_get0_public_key(_ec_key);
BIGNUM *pub_bn = BN_new();
::EC_POINT_point2bn(ec_group, pub, POINT_CONVERSION_UNCOMPRESSED, pub_bn, _bn_ctx);
p_bin_key.resize(BN_num_bytes(pub_bn));
::BN_bn2bin(pub_bn, p_bin_key.data());
::BN_clear_free(pub_bn);
return 0;
}