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Use EVP_aes_256_ctr for AES CTR implementation.

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GitOrigin-RevId: e9218b6eec8f5e4a11eea24324f6c8478f6f1293
This commit is contained in:
levlam 2020-09-27 15:46:11 +03:00
parent a7ba1e3e12
commit 4d67801710
2 changed files with 16 additions and 48 deletions
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62
tdutils/td/utils/crypto.cpp
View File

@ -396,6 +396,10 @@ class Evp {
init(Type::Cbc, false, EVP_aes_256_cbc(), key);
}
void init_encrypt_ctr(Slice key) {
init(Type::Ctr, true, EVP_aes_256_ctr(), key);
}
void init_iv(Slice iv) {
int res = EVP_CipherInit_ex(ctx_, nullptr, nullptr, nullptr, iv.ubegin(), -1);
LOG_IF(FATAL, res != 1);
@ -403,7 +407,7 @@ class Evp {
void encrypt(const uint8 *src, uint8 *dst, int size) {
// CHECK(type_ != Type::Empty && is_encrypt_);
CHECK(size % AES_BLOCK_SIZE == 0);
// CHECK(size % AES_BLOCK_SIZE == 0);
int len;
int res = EVP_EncryptUpdate(ctx_, dst, &len, src, size);
LOG_IF(FATAL, res != 1);
@ -421,7 +425,7 @@ class Evp {
private:
EVP_CIPHER_CTX *ctx_{nullptr};
enum class Type : int8 { Empty, Ecb, Cbc };
enum class Type : int8 { Empty, Ecb, Cbc, Ctr };
// Type type_{Type::Empty};
// bool is_encrypt_ = false;
@ -627,49 +631,8 @@ void AesCbcState::decrypt(Slice from, MutableSlice to) {
::td::aes_cbc_decrypt(raw_.key.as_slice(), raw_.iv.as_mutable_slice(), from, to);
}
class AesCtrState::Impl {
public:
Impl(Slice key, Slice iv) {
CHECK(key.size() == 32);
CHECK(iv.size() == 16);
static_assert(AES_BLOCK_SIZE == 16, "");
evp_.init_encrypt_ecb(key);
counter_.load(iv.ubegin());
fill();
}
void encrypt(Slice from, MutableSlice to) {
auto *src = from.ubegin();
auto *dst = to.ubegin();
auto n = from.size();
while (n != 0) {
size_t left = encrypted_counter_.raw() + AesCtrCounterPack::size() - current_;
if (left == 0) {
fill();
left = AesCtrCounterPack::size();
}
size_t min_n = td::min(n, left);
XorBytes::run(src, current_, dst, min_n);
src += min_n;
dst += min_n;
n -= min_n;
current_ += min_n;
}
}
private:
struct AesCtrState::Impl {
Evp evp_;
uint8 *current_;
AesBlock counter_;
AesCtrCounterPack encrypted_counter_;
void fill() {
encrypted_counter_.init(counter_);
counter_ = encrypted_counter_.blocks[AesCtrCounterPack::BLOCK_COUNT - 1].inc();
current_ = encrypted_counter_.raw();
evp_.encrypt(current_, current_, static_cast<int>(AesCtrCounterPack::size()));
}
};
AesCtrState::AesCtrState() = default;
@ -678,15 +641,20 @@ AesCtrState &AesCtrState::operator=(AesCtrState &&from) = default;
AesCtrState::~AesCtrState() = default;
void AesCtrState::init(Slice key, Slice iv) {
ctx_ = make_unique<AesCtrState::Impl>(key, iv);
CHECK(key.size() == 32);
CHECK(iv.size() == 16);
ctx_ = make_unique<AesCtrState::Impl>();
ctx_->evp_.init_encrypt_ctr(key);
ctx_->evp_.init_iv(iv);
}
void AesCtrState::encrypt(Slice from, MutableSlice to) {
ctx_->encrypt(from, to);
CHECK(from.size() <= to.size());
ctx_->evp_.encrypt(from.ubegin(), to.ubegin(), from.size());
}
void AesCtrState::decrypt(Slice from, MutableSlice to) {
encrypt(from, to); // it is the same as decrypt
encrypt(from, to);
}
void sha1(Slice data, unsigned char output[20]) {

2
tdutils/td/utils/crypto.h
View File

@ -84,7 +84,7 @@ class AesCtrState {
void decrypt(Slice from, MutableSlice to);
private:
class Impl;
struct Impl;
unique_ptr<Impl> ctx_;
};