tdesktop/Telegram/SourceFiles/passport/passport_encryption.cpp
2019-09-06 19:31:07 +03:00

437 lines
13 KiB
C++

/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.
For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#include "passport/passport_encryption.h"
#include "base/openssl_help.h"
#include "mtproto/rsa_public_key.h"
#include <QtCore/QJsonDocument>
#include <QtCore/QJsonArray>
#include <QtCore/QJsonObject>
namespace Passport {
namespace {
constexpr auto kAesKeyLength = 32;
constexpr auto kAesIvLength = 16;
constexpr auto kSecretSize = 32;
constexpr auto kAesParamsHashSize = 64;
constexpr auto kMinPadding = 32;
constexpr auto kMaxPadding = 255;
constexpr auto kAlignTo = 16;
} // namespace
struct AesParams {
bytes::vector key;
bytes::vector iv;
};
AesParams PrepareAesParamsWithHash(bytes::const_span hashForEncryptionKey) {
Expects(hashForEncryptionKey.size() == kAesParamsHashSize);
auto result = AesParams();
result.key = bytes::make_vector(
hashForEncryptionKey.subspan(0, kAesKeyLength));
result.iv = bytes::make_vector(
hashForEncryptionKey.subspan(kAesKeyLength, kAesIvLength));
return result;
}
AesParams PrepareAesParams(bytes::const_span bytesForEncryptionKey) {
return PrepareAesParamsWithHash(openssl::Sha512(bytesForEncryptionKey));
}
bytes::vector EncryptOrDecrypt(
bytes::const_span initial,
AesParams &&params,
int encryptOrDecrypt) {
Expects((initial.size() & 0x0F) == 0);
Expects(params.key.size() == kAesKeyLength);
Expects(params.iv.size() == kAesIvLength);
auto aesKey = AES_KEY();
const auto error = (encryptOrDecrypt == AES_ENCRYPT)
? AES_set_encrypt_key(
reinterpret_cast<const uchar*>(params.key.data()),
params.key.size() * CHAR_BIT,
&aesKey)
: AES_set_decrypt_key(
reinterpret_cast<const uchar*>(params.key.data()),
params.key.size() * CHAR_BIT,
&aesKey);
if (error != 0) {
LOG(("App Error: Could not AES_set_encrypt_key, result %1"
).arg(error));
return {};
}
auto result = bytes::vector(initial.size());
AES_cbc_encrypt(
reinterpret_cast<const uchar*>(initial.data()),
reinterpret_cast<uchar*>(result.data()),
initial.size(),
&aesKey,
reinterpret_cast<uchar*>(params.iv.data()),
encryptOrDecrypt);
return result;
}
bytes::vector Encrypt(
bytes::const_span decrypted,
AesParams &&params) {
return EncryptOrDecrypt(decrypted, std::move(params), AES_ENCRYPT);
}
bytes::vector Decrypt(
bytes::const_span encrypted,
AesParams &&params) {
return EncryptOrDecrypt(encrypted, std::move(params), AES_DECRYPT);
}
bool CheckBytesMod255(bytes::const_span bytes) {
const auto full = ranges::accumulate(
bytes,
0ULL,
[](uint64 sum, gsl::byte value) { return sum + uchar(value); });
const auto mod = (full % 255ULL);
return (mod == 239);
}
bool CheckSecretBytes(bytes::const_span secret) {
return CheckBytesMod255(secret);
}
bytes::vector GenerateSecretBytes() {
auto result = bytes::vector(kSecretSize);
memset_rand(result.data(), result.size());
const auto full = ranges::accumulate(
result,
0ULL,
[](uint64 sum, gsl::byte value) { return sum + uchar(value); });
const auto mod = (full % 255ULL);
const auto add = 255ULL + 239 - mod;
auto first = (static_cast<uchar>(result[0]) + add) % 255ULL;
result[0] = static_cast<gsl::byte>(first);
return result;
}
bytes::vector DecryptSecretBytesWithHash(
bytes::const_span encryptedSecret,
bytes::const_span hashForEncryptionKey) {
if (encryptedSecret.empty()) {
return {};
} else if (encryptedSecret.size() != kSecretSize) {
LOG(("API Error: Wrong secret size %1"
).arg(encryptedSecret.size()));
return {};
}
auto params = PrepareAesParamsWithHash(hashForEncryptionKey);
auto result = Decrypt(encryptedSecret, std::move(params));
if (!CheckSecretBytes(result)) {
LOG(("API Error: Bad secret bytes."));
return {};
}
return result;
}
bytes::vector DecryptSecretBytes(
bytes::const_span encryptedSecret,
bytes::const_span bytesForEncryptionKey) {
return DecryptSecretBytesWithHash(
encryptedSecret,
openssl::Sha512(bytesForEncryptionKey));
}
bytes::vector EncryptSecretBytesWithHash(
bytes::const_span secret,
bytes::const_span hashForEncryptionKey) {
Expects(secret.size() == kSecretSize);
Expects(CheckSecretBytes(secret) == true);
auto params = PrepareAesParamsWithHash(hashForEncryptionKey);
return Encrypt(secret, std::move(params));
}
bytes::vector EncryptSecretBytes(
bytes::const_span secret,
bytes::const_span bytesForEncryptionKey) {
Expects(secret.size() == kSecretSize);
Expects(CheckSecretBytes(secret) == true);
auto params = PrepareAesParams(bytesForEncryptionKey);
return Encrypt(secret, std::move(params));
}
bytes::vector DecryptSecureSecret(
bytes::const_span encryptedSecret,
bytes::const_span passwordHashForSecret) {
Expects(!encryptedSecret.empty());
return DecryptSecretBytesWithHash(
encryptedSecret,
passwordHashForSecret);
}
bytes::vector EncryptSecureSecret(
bytes::const_span secret,
bytes::const_span passwordHashForSecret) {
Expects(secret.size() == kSecretSize);
return EncryptSecretBytesWithHash(secret, passwordHashForSecret);
}
bytes::vector SerializeData(const std::map<QString, QString> &data) {
auto root = QJsonObject();
for (const auto &[key, value] : data) {
root.insert(key, value);
}
auto document = QJsonDocument(root);
const auto result = document.toJson(QJsonDocument::Compact);
return bytes::make_vector(result);
}
std::map<QString, QString> DeserializeData(bytes::const_span bytes) {
const auto serialized = QByteArray::fromRawData(
reinterpret_cast<const char*>(bytes.data()),
bytes.size());
auto error = QJsonParseError();
auto document = QJsonDocument::fromJson(serialized, &error);
if (error.error != QJsonParseError::NoError) {
LOG(("API Error: Could not deserialize decrypted JSON, error %1"
).arg(error.errorString()));
return {};
} else if (!document.isObject()) {
LOG(("API Error: decrypted JSON root is not an object."));
return {};
}
auto object = document.object();
auto result = std::map<QString, QString>();
for (auto i = object.constBegin(), e = object.constEnd(); i != e; ++i) {
const auto key = i.key();
switch ((*i).type()) {
case QJsonValue::Null: {
LOG(("API Error: null found inside decrypted JSON root. "
"Defaulting to empty string value."));
result[key] = QString();
} break;
case QJsonValue::Undefined: {
LOG(("API Error: undefined found inside decrypted JSON root. "
"Defaulting to empty string value."));
result[key] = QString();
} break;
case QJsonValue::Bool: {
LOG(("API Error: bool found inside decrypted JSON root. "
"Aborting."));
return {};
} break;
case QJsonValue::Double: {
LOG(("API Error: double found inside decrypted JSON root. "
"Converting to string."));
result[key] = QString::number((*i).toDouble());
} break;
case QJsonValue::String: {
result[key] = (*i).toString();
} break;
case QJsonValue::Array: {
LOG(("API Error: array found inside decrypted JSON root. "
"Aborting."));
return {};
} break;
case QJsonValue::Object: {
LOG(("API Error: object found inside decrypted JSON root. "
"Aborting."));
return {};
} break;
}
}
return result;
}
std::vector<DataError> DeserializeErrors(bytes::const_span json) {
const auto serialized = QByteArray::fromRawData(
reinterpret_cast<const char*>(json.data()),
json.size());
auto error = QJsonParseError();
auto document = QJsonDocument::fromJson(serialized, &error);
if (error.error != QJsonParseError::NoError) {
LOG(("API Error: Could not deserialize errors JSON, error %1"
).arg(error.errorString()));
return {};
} else if (!document.isArray()) {
LOG(("API Error: Errors JSON root is not an array."));
return {};
}
auto array = document.array();
auto result = std::vector<DataError>();
for (const auto &error : array) {
if (!error.isObject()) {
LOG(("API Error: Not an object inside errors JSON."));
continue;
}
auto fields = error.toObject();
const auto typeIt = fields.constFind("type");
if (typeIt == fields.constEnd()) {
LOG(("API Error: type was not found in an error."));
continue;
} else if (!(*typeIt).isString()) {
LOG(("API Error: type was not a string in an error."));
continue;
}
const auto descriptionIt = fields.constFind("description");
if (descriptionIt == fields.constEnd()) {
LOG(("API Error: description was not found in an error."));
continue;
} else if (!(*typeIt).isString()) {
LOG(("API Error: description was not a string in an error."));
continue;
}
const auto targetIt = fields.constFind("target");
if (targetIt == fields.constEnd()) {
LOG(("API Error: target aws not found in an error."));
continue;
} else if (!(*targetIt).isString()) {
LOG(("API Error: target was not as string in an error."));
continue;
}
auto next = DataError();
next.type = (*typeIt).toString();
next.text = (*descriptionIt).toString();
const auto fieldIt = fields.constFind("field");
const auto fileHashIt = fields.constFind("file_hash");
if (fieldIt != fields.constEnd()) {
if (!(*fieldIt).isString()) {
LOG(("API Error: field was not a string in an error."));
continue;
}
next.key = (*fieldIt).toString();
} else if (fileHashIt != fields.constEnd()) {
if (!(*fileHashIt).isString()) {
LOG(("API Error: file_hash was not a string in an error."));
continue;
}
next.key = QByteArray::fromBase64(
(*fileHashIt).toString().toUtf8());
} else if ((*targetIt).toString() == "selfie") {
next.key = QByteArray();
}
result.push_back(std::move(next));
}
return result;
}
EncryptedData EncryptData(bytes::const_span bytes) {
return EncryptData(bytes, GenerateSecretBytes());
}
EncryptedData EncryptData(
bytes::const_span bytes,
bytes::const_span dataSecret) {
constexpr auto kFromPadding = kMinPadding + kAlignTo - 1;
constexpr auto kPaddingDelta = kMaxPadding - kFromPadding;
const auto randomPadding = kFromPadding
+ (rand_value<uint32>() % kPaddingDelta);
const auto padding = randomPadding
- ((bytes.size() + randomPadding) % kAlignTo);
Assert(padding >= kMinPadding && padding <= kMaxPadding);
auto unencrypted = bytes::vector(padding + bytes.size());
Assert(unencrypted.size() % kAlignTo == 0);
unencrypted[0] = static_cast<gsl::byte>(padding);
memset_rand(unencrypted.data() + 1, padding - 1);
bytes::copy(
gsl::make_span(unencrypted).subspan(padding),
bytes);
const auto dataHash = openssl::Sha256(unencrypted);
const auto bytesForEncryptionKey = bytes::concatenate(
dataSecret,
dataHash);
auto params = PrepareAesParams(bytesForEncryptionKey);
return {
{ dataSecret.begin(), dataSecret.end() },
{ dataHash.begin(), dataHash.end() },
Encrypt(unencrypted, std::move(params))
};
}
bytes::vector DecryptData(
bytes::const_span encrypted,
bytes::const_span dataHash,
bytes::const_span dataSecret) {
constexpr auto kDataHashSize = 32;
if (encrypted.empty()) {
return {};
} else if (dataHash.size() != kDataHashSize) {
LOG(("API Error: Bad data hash size %1").arg(dataHash.size()));
return {};
} else if (dataSecret.size() != kSecretSize) {
LOG(("API Error: Bad data secret size %1").arg(dataSecret.size()));
return {};
}
const auto bytesForEncryptionKey = bytes::concatenate(
dataSecret,
dataHash);
auto params = PrepareAesParams(bytesForEncryptionKey);
const auto decrypted = Decrypt(encrypted, std::move(params));
if (bytes::compare(openssl::Sha256(decrypted), dataHash) != 0) {
LOG(("API Error: Bad data hash."));
return {};
}
const auto padding = static_cast<uint32>(decrypted[0]);
if (padding < kMinPadding
|| padding > kMaxPadding
|| padding > decrypted.size()) {
LOG(("API Error: Bad padding value %1").arg(padding));
return {};
}
const auto bytes = gsl::make_span(decrypted).subspan(padding);
return { bytes.begin(), bytes.end() };
}
bytes::vector PrepareValueHash(
bytes::const_span dataHash,
bytes::const_span valueSecret) {
return openssl::Sha256(dataHash, valueSecret);
}
bytes::vector EncryptValueSecret(
bytes::const_span valueSecret,
bytes::const_span secret,
bytes::const_span valueHash) {
const auto bytesForEncryptionKey = bytes::concatenate(
secret,
valueHash);
return EncryptSecretBytes(valueSecret, bytesForEncryptionKey);
}
bytes::vector DecryptValueSecret(
bytes::const_span encrypted,
bytes::const_span secret,
bytes::const_span valueHash) {
const auto bytesForEncryptionKey = bytes::concatenate(
secret,
valueHash);
return DecryptSecretBytes(encrypted, bytesForEncryptionKey);
}
uint64 CountSecureSecretId(bytes::const_span secret) {
const auto full = openssl::Sha256(secret);
return *reinterpret_cast<const uint64*>(full.data());
}
bytes::vector EncryptCredentialsSecret(
bytes::const_span secret,
bytes::const_span publicKey) {
const auto key = MTP::internal::RSAPublicKey(publicKey);
return key.encryptOAEPpadding(secret);
}
} // namespace Passport