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LibCrypto+LibTLS: Generalise the use of IV length

This is in preparation for the upcoming Galois/Counter mode, which
conventionally has 12 bytes of IV as opposed to CBC's 16 bytes.

...Also fixes a lot of style issues, since the author finally found the
project's clang config file in the repository root :^)
This commit is contained in:
AnotherTest 2020-04-23 02:53:11 +04:30 committed by Andreas Kling
parent 7384d58a0a
commit a1e1570552
7 changed files with 3110 additions and 3060 deletions

View file

@ -30,165 +30,165 @@
namespace Crypto {
namespace Cipher {
template <typename T>
constexpr u32 get_key(T pt)
{
return ((u32)(pt)[0] << 24) ^ ((u32)(pt)[1] << 16) ^ ((u32)(pt)[2] << 8) ^ ((u32)(pt)[3]);
template<typename T>
constexpr u32 get_key(T pt)
{
return ((u32)(pt)[0] << 24) ^ ((u32)(pt)[1] << 16) ^ ((u32)(pt)[2] << 8) ^ ((u32)(pt)[3]);
}
constexpr void swap_keys(u32* keys, size_t i, size_t j)
{
u32 temp = keys[i];
keys[i] = keys[j];
keys[j] = temp;
}
String AESCipherBlock::to_string() const
{
StringBuilder builder;
for (size_t i = 0; i < BlockSizeInBits / 8; ++i)
builder.appendf("%02x", m_data[i]);
return builder.build();
}
String AESCipherKey::to_string() const
{
StringBuilder builder;
for (size_t i = 0; i < (rounds() + 1) * 4; ++i)
builder.appendf("%02x", m_rd_keys[i]);
return builder.build();
}
void AESCipherKey::expand_encrypt_key(const ByteBuffer& user_key, size_t bits)
{
u32* round_key;
u32 temp;
size_t i { 0 };
ASSERT(!user_key.is_null());
ASSERT(is_valid_key_size(bits));
round_key = round_keys();
if (bits == 128) {
m_rounds = 10;
} else if (bits == 192) {
m_rounds = 12;
} else {
m_rounds = 14;
}
constexpr void swap_keys(u32* keys, size_t i, size_t j)
{
u32 temp = keys[i];
keys[i] = keys[j];
keys[j] = temp;
}
String AESCipherBlock::to_string() const
{
StringBuilder builder;
for (size_t i = 0; i < BLOCK_SIZE / 8; ++i)
builder.appendf("%02x", m_data[i]);
return builder.build();
}
String AESCipherKey::to_string() const
{
StringBuilder builder;
for (size_t i = 0; i < (rounds() + 1) * 4; ++i)
builder.appendf("%02x", m_rd_keys[i]);
return builder.build();
}
void AESCipherKey::expand_encrypt_key(const ByteBuffer& user_key, size_t bits)
{
u32* round_key;
u32 temp;
size_t i { 0 };
ASSERT(!user_key.is_null());
ASSERT(is_valid_key_size(bits));
round_key = round_keys();
if (bits == 128) {
m_rounds = 10;
} else if (bits == 192) {
m_rounds = 12;
} else {
m_rounds = 14;
}
round_key[0] = get_key(user_key.slice_view(0, 4).data());
round_key[1] = get_key(user_key.slice_view(4, 4).data());
round_key[2] = get_key(user_key.slice_view(8, 4).data());
round_key[3] = get_key(user_key.slice_view(12, 4).data());
if (bits == 128) {
for (;;) {
temp = round_key[3];
// clang-format off
round_key[0] = get_key(user_key.slice_view(0, 4).data());
round_key[1] = get_key(user_key.slice_view(4, 4).data());
round_key[2] = get_key(user_key.slice_view(8, 4).data());
round_key[3] = get_key(user_key.slice_view(12, 4).data());
if (bits == 128) {
for (;;) {
temp = round_key[3];
// clang-format off
round_key[4] = round_key[0] ^
(AESTables::Encode2[(temp >> 16) & 0xff] & 0xff000000) ^
(AESTables::Encode3[(temp >> 8) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(temp ) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(temp >> 24) ] & 0x000000ff) ^ AESTables::RCON[i];
// clang-format on
round_key[5] = round_key[1] ^ round_key[4];
round_key[6] = round_key[2] ^ round_key[5];
round_key[7] = round_key[3] ^ round_key[6];
++i;
if (i == 10)
break;
round_key += 4;
}
return;
// clang-format on
round_key[5] = round_key[1] ^ round_key[4];
round_key[6] = round_key[2] ^ round_key[5];
round_key[7] = round_key[3] ^ round_key[6];
++i;
if (i == 10)
break;
round_key += 4;
}
return;
}
round_key[4] = get_key(user_key.slice_view(16, 4).data());
round_key[5] = get_key(user_key.slice_view(20, 4).data());
if (bits == 192) {
for (;;) {
temp = round_key[5];
// clang-format off
round_key[4] = get_key(user_key.slice_view(16, 4).data());
round_key[5] = get_key(user_key.slice_view(20, 4).data());
if (bits == 192) {
for (;;) {
temp = round_key[5];
// clang-format off
round_key[6] = round_key[0] ^
(AESTables::Encode2[(temp >> 16) & 0xff] & 0xff000000) ^
(AESTables::Encode3[(temp >> 8) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(temp ) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(temp >> 24) ] & 0x000000ff) ^ AESTables::RCON[i];
// clang-format on
round_key[7] = round_key[1] ^ round_key[6];
round_key[8] = round_key[2] ^ round_key[7];
round_key[9] = round_key[3] ^ round_key[8];
// clang-format on
round_key[7] = round_key[1] ^ round_key[6];
round_key[8] = round_key[2] ^ round_key[7];
round_key[9] = round_key[3] ^ round_key[8];
++i;
if (i == 8)
break;
++i;
if (i == 8)
break;
round_key[10] = round_key[4] ^ round_key[9];
round_key[11] = round_key[5] ^ round_key[10];
round_key[10] = round_key[4] ^ round_key[9];
round_key[11] = round_key[5] ^ round_key[10];
round_key += 6;
}
return;
round_key += 6;
}
return;
}
round_key[6] = get_key(user_key.slice_view(24, 4).data());
round_key[7] = get_key(user_key.slice_view(28, 4).data());
if (true) { // bits == 256
for (;;) {
temp = round_key[7];
// clang-format off
round_key[6] = get_key(user_key.slice_view(24, 4).data());
round_key[7] = get_key(user_key.slice_view(28, 4).data());
if (true) { // bits == 256
for (;;) {
temp = round_key[7];
// clang-format off
round_key[8] = round_key[0] ^
(AESTables::Encode2[(temp >> 16) & 0xff] & 0xff000000) ^
(AESTables::Encode3[(temp >> 8) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(temp ) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(temp >> 24) ] & 0x000000ff) ^ AESTables::RCON[i];
// clang-format on
round_key[9] = round_key[1] ^ round_key[8];
round_key[10] = round_key[2] ^ round_key[9];
round_key[11] = round_key[3] ^ round_key[10];
// clang-format on
round_key[9] = round_key[1] ^ round_key[8];
round_key[10] = round_key[2] ^ round_key[9];
round_key[11] = round_key[3] ^ round_key[10];
++i;
if (i == 7)
break;
++i;
if (i == 7)
break;
temp = round_key[11];
// clang-format off
temp = round_key[11];
// clang-format off
round_key[12] = round_key[4] ^
(AESTables::Encode2[(temp >> 24) ] & 0xff000000) ^
(AESTables::Encode3[(temp >> 16) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(temp >> 8) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(temp ) & 0xff] & 0x000000ff) ;
// clang-format on
round_key[13] = round_key[5] ^ round_key[12];
round_key[14] = round_key[6] ^ round_key[13];
round_key[15] = round_key[7] ^ round_key[14];
// clang-format on
round_key[13] = round_key[5] ^ round_key[12];
round_key[14] = round_key[6] ^ round_key[13];
round_key[15] = round_key[7] ^ round_key[14];
round_key += 8;
}
return;
round_key += 8;
}
return;
}
}
void AESCipherKey::expand_decrypt_key(const ByteBuffer& user_key, size_t bits)
{
u32* round_key;
expand_encrypt_key(user_key, bits);
round_key = round_keys();
// reorder round keys
for (size_t i = 0, j = 4 * rounds(); i < j; i += 4, j -= 4) {
swap_keys(round_key, i, j);
swap_keys(round_key, i + 1, j + 1);
swap_keys(round_key, i + 2, j + 2);
swap_keys(round_key, i + 3, j + 3);
}
void AESCipherKey::expand_decrypt_key(const ByteBuffer& user_key, size_t bits)
{
u32* round_key;
expand_encrypt_key(user_key, bits);
round_key = round_keys();
// reorder round keys
for (size_t i = 0, j = 4 * rounds(); i < j; i += 4, j -= 4) {
swap_keys(round_key, i, j);
swap_keys(round_key, i + 1, j + 1);
swap_keys(round_key, i + 2, j + 2);
swap_keys(round_key, i + 3, j + 3);
}
// apply inverse mix-column to middle rounds
for (size_t i = 1; i < rounds(); ++i) {
round_key += 4;
// clang-format off
// apply inverse mix-column to middle rounds
for (size_t i = 1; i < rounds(); ++i) {
round_key += 4;
// clang-format off
round_key[0] =
AESTables::Decode0[AESTables::Encode1[(round_key[0] >> 24) ] & 0xff] ^
AESTables::Decode1[AESTables::Encode1[(round_key[0] >> 16) & 0xff] & 0xff] ^
@ -209,30 +209,30 @@ namespace Cipher {
AESTables::Decode1[AESTables::Encode1[(round_key[3] >> 16) & 0xff] & 0xff] ^
AESTables::Decode2[AESTables::Encode1[(round_key[3] >> 8) & 0xff] & 0xff] ^
AESTables::Decode3[AESTables::Encode1[(round_key[3] ) & 0xff] & 0xff] ;
// clang-format on
}
// clang-format on
}
}
void AESCipher::encrypt_block(const AESCipherBlock& in, AESCipherBlock& out)
{
u32 s0, s1, s2, s3, t0, t1, t2, t3;
size_t r { 0 };
void AESCipher::encrypt_block(const AESCipherBlock& in, AESCipherBlock& out)
{
u32 s0, s1, s2, s3, t0, t1, t2, t3;
size_t r { 0 };
const auto& dec_key = key();
const auto* round_keys = dec_key.round_keys();
const auto& dec_key = key();
const auto* round_keys = dec_key.round_keys();
s0 = get_key(in.data().offset_pointer(0)) ^ round_keys[0];
s1 = get_key(in.data().offset_pointer(4)) ^ round_keys[1];
s2 = get_key(in.data().offset_pointer(8)) ^ round_keys[2];
s3 = get_key(in.data().offset_pointer(12)) ^ round_keys[3];
s0 = get_key(in.data().offset_pointer(0)) ^ round_keys[0];
s1 = get_key(in.data().offset_pointer(4)) ^ round_keys[1];
s2 = get_key(in.data().offset_pointer(8)) ^ round_keys[2];
s3 = get_key(in.data().offset_pointer(12)) ^ round_keys[3];
r = dec_key.rounds() >> 1;
r = dec_key.rounds() >> 1;
// apply the first |r - 1| rounds
auto i { 0 };
for (;;) {
++i;
// clang-format off
// apply the first |r - 1| rounds
auto i { 0 };
for (;;) {
++i;
// clang-format off
t0 = AESTables::Encode0[(s0 >> 24) ] ^
AESTables::Encode1[(s1 >> 16) & 0xff] ^
AESTables::Encode2[(s2 >> 8) & 0xff] ^
@ -249,15 +249,15 @@ namespace Cipher {
AESTables::Encode1[(s0 >> 16) & 0xff] ^
AESTables::Encode2[(s1 >> 8) & 0xff] ^
AESTables::Encode3[(s2 ) & 0xff] ^ round_keys[7];
// clang-format on
// clang-format on
round_keys += 8;
--r;
++i;
if (r == 0)
break;
round_keys += 8;
--r;
++i;
if (r == 0)
break;
// clang-format off
// clang-format off
s0 = AESTables::Encode0[(t0 >> 24) ] ^
AESTables::Encode1[(t1 >> 16) & 0xff] ^
AESTables::Encode2[(t2 >> 8) & 0xff] ^
@ -274,11 +274,11 @@ namespace Cipher {
AESTables::Encode1[(t0 >> 16) & 0xff] ^
AESTables::Encode2[(t1 >> 8) & 0xff] ^
AESTables::Encode3[(t2 ) & 0xff] ^ round_keys[3];
// clang-format on
}
// clang-format on
}
// apply the last round and put the encrypted data into out
// clang-format off
// apply the last round and put the encrypted data into out
// clang-format off
s0 = (AESTables::Encode2[(t0 >> 24) ] & 0xff000000) ^
(AESTables::Encode3[(t1 >> 16) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(t2 >> 8) & 0xff] & 0x0000ff00) ^
@ -302,28 +302,28 @@ namespace Cipher {
(AESTables::Encode0[(t1 >> 8) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(t2 ) & 0xff] & 0x000000ff) ^ round_keys[3];
out.put(12, s3);
// clang-format on
}
// clang-format on
}
void AESCipher::decrypt_block(const AESCipherBlock& in, AESCipherBlock& out)
{
void AESCipher::decrypt_block(const AESCipherBlock& in, AESCipherBlock& out)
{
u32 s0, s1, s2, s3, t0, t1, t2, t3;
size_t r { 0 };
u32 s0, s1, s2, s3, t0, t1, t2, t3;
size_t r { 0 };
const auto& dec_key = key();
const auto* round_keys = dec_key.round_keys();
const auto& dec_key = key();
const auto* round_keys = dec_key.round_keys();
s0 = get_key(in.data().offset_pointer(0)) ^ round_keys[0];
s1 = get_key(in.data().offset_pointer(4)) ^ round_keys[1];
s2 = get_key(in.data().offset_pointer(8)) ^ round_keys[2];
s3 = get_key(in.data().offset_pointer(12)) ^ round_keys[3];
s0 = get_key(in.data().offset_pointer(0)) ^ round_keys[0];
s1 = get_key(in.data().offset_pointer(4)) ^ round_keys[1];
s2 = get_key(in.data().offset_pointer(8)) ^ round_keys[2];
s3 = get_key(in.data().offset_pointer(12)) ^ round_keys[3];
r = dec_key.rounds() >> 1;
r = dec_key.rounds() >> 1;
// apply the first |r - 1| rounds
for (;;) {
// clang-format off
// apply the first |r - 1| rounds
for (;;) {
// clang-format off
t0 = AESTables::Decode0[(s0 >> 24) ] ^
AESTables::Decode1[(s3 >> 16) & 0xff] ^
AESTables::Decode2[(s2 >> 8) & 0xff] ^
@ -340,14 +340,14 @@ namespace Cipher {
AESTables::Decode1[(s2 >> 16) & 0xff] ^
AESTables::Decode2[(s1 >> 8) & 0xff] ^
AESTables::Decode3[(s0 ) & 0xff] ^ round_keys[7];
// clang-format on
// clang-format on
round_keys += 8;
--r;
if (r == 0)
break;
round_keys += 8;
--r;
if (r == 0)
break;
// clang-format off
// clang-format off
s0 = AESTables::Decode0[(t0 >> 24) ] ^
AESTables::Decode1[(t3 >> 16) & 0xff] ^
AESTables::Decode2[(t2 >> 8) & 0xff] ^
@ -364,11 +364,11 @@ namespace Cipher {
AESTables::Decode1[(t2 >> 16) & 0xff] ^
AESTables::Decode2[(t1 >> 8) & 0xff] ^
AESTables::Decode3[(t0 ) & 0xff] ^ round_keys[3];
// clang-format on
}
// clang-format on
}
// apply the last round and put the decrypted data into out
// clang-format off
// apply the last round and put the decrypted data into out
// clang-format off
s0 = ((u32)AESTables::Decode4[(t0 >> 24) ] << 24) ^
((u32)AESTables::Decode4[(t3 >> 16) & 0xff] << 16) ^
((u32)AESTables::Decode4[(t2 >> 8) & 0xff] << 8) ^
@ -392,39 +392,39 @@ namespace Cipher {
((u32)AESTables::Decode4[(t1 >> 8) & 0xff] << 8) ^
((u32)AESTables::Decode4[(t0 ) & 0xff] ) ^ round_keys[3];
out.put(12, s3);
// clang-format on
}
// clang-format on
}
void AESCipherBlock::overwrite(const ByteBuffer& buffer)
{
overwrite(buffer.data(), buffer.size());
}
void AESCipherBlock::overwrite(const ByteBuffer& buffer)
{
overwrite(buffer.data(), buffer.size());
}
void AESCipherBlock::overwrite(const u8* data, size_t length)
{
ASSERT(length <= m_data.size());
m_data.overwrite(0, data, length);
if (length < m_data.size()) {
switch (padding_mode()) {
case PaddingMode::Null:
// fill with zeros
__builtin_memset(m_data.data() + length, 0, m_data.size() - length);
break;
case PaddingMode::CMS:
// fill with the length of the padding bytes
__builtin_memset(m_data.data() + length, m_data.size() - length, m_data.size() - length);
break;
case PaddingMode::RFC5246:
// fill with the length of the padding bytes minus one
__builtin_memset(m_data.data() + length, m_data.size() - length - 1, m_data.size() - length);
break;
default:
// FIXME: We should handle the rest of the common padding modes
ASSERT_NOT_REACHED();
break;
}
void AESCipherBlock::overwrite(const u8* data, size_t length)
{
ASSERT(length <= m_data.size());
m_data.overwrite(0, data, length);
if (length < m_data.size()) {
switch (padding_mode()) {
case PaddingMode::Null:
// fill with zeros
__builtin_memset(m_data.data() + length, 0, m_data.size() - length);
break;
case PaddingMode::CMS:
// fill with the length of the padding bytes
__builtin_memset(m_data.data() + length, m_data.size() - length, m_data.size() - length);
break;
case PaddingMode::RFC5246:
// fill with the length of the padding bytes minus one
__builtin_memset(m_data.data() + length, m_data.size() - length - 1, m_data.size() - length);
break;
default:
// FIXME: We should handle the rest of the common padding modes
ASSERT_NOT_REACHED();
break;
}
}
}
}
}

File diff suppressed because it is too large Load diff

View file

@ -33,108 +33,108 @@
namespace Crypto {
namespace Cipher {
enum class Intent {
Encryption,
Decryption,
};
enum class Intent {
Encryption,
Decryption,
};
enum class PaddingMode {
CMS, // RFC 1423
RFC5246, // very similar to CMS, but filled with |length - 1|, instead of |length|
Null,
// FIXME: We do not implement these yet
Bit,
Random,
Space,
ZeroLength,
};
enum class PaddingMode {
CMS, // RFC 1423
RFC5246, // very similar to CMS, but filled with |length - 1|, instead of |length|
Null,
// FIXME: We do not implement these yet
Bit,
Random,
Space,
ZeroLength,
};
template <typename B, typename T>
class Cipher;
template<typename B, typename T>
class Cipher;
struct CipherBlock {
public:
explicit CipherBlock(PaddingMode mode)
: m_padding_mode(mode)
{
}
struct CipherBlock {
public:
explicit CipherBlock(PaddingMode mode)
: m_padding_mode(mode)
{
}
static size_t block_size() { ASSERT_NOT_REACHED(); }
static size_t block_size() { ASSERT_NOT_REACHED(); }
virtual ByteBuffer get() const = 0;
virtual const ByteBuffer& data() const = 0;
virtual ByteBuffer get() const = 0;
virtual const ByteBuffer& data() const = 0;
virtual void overwrite(const ByteBuffer&) = 0;
virtual void overwrite(const u8*, size_t) = 0;
virtual void overwrite(const ByteBuffer&) = 0;
virtual void overwrite(const u8*, size_t) = 0;
virtual void apply_initialization_vector(const u8* ivec) = 0;
virtual void apply_initialization_vector(const u8* ivec) = 0;
PaddingMode padding_mode() const { return m_padding_mode; }
PaddingMode padding_mode() const { return m_padding_mode; }
template <typename T>
void put(size_t offset, T value)
{
ASSERT(offset + sizeof(T) <= data().size());
auto* ptr = data().data() + offset;
auto index { 0 };
template<typename T>
void put(size_t offset, T value)
{
ASSERT(offset + sizeof(T) <= data().size());
auto* ptr = data().data() + offset;
auto index { 0 };
ASSERT(sizeof(T) <= 4);
ASSERT(sizeof(T) <= 4);
if constexpr (sizeof(T) > 3)
ptr[index++] = (u8)(value >> 24);
if constexpr (sizeof(T) > 3)
ptr[index++] = (u8)(value >> 24);
if constexpr (sizeof(T) > 2)
ptr[index++] = (u8)(value >> 16);
if constexpr (sizeof(T) > 2)
ptr[index++] = (u8)(value >> 16);
if constexpr (sizeof(T) > 1)
ptr[index++] = (u8)(value >> 8);
if constexpr (sizeof(T) > 1)
ptr[index++] = (u8)(value >> 8);
ptr[index] = (u8)value;
}
ptr[index] = (u8)value;
}
private:
virtual ByteBuffer& data() = 0;
PaddingMode m_padding_mode;
};
private:
virtual ByteBuffer& data() = 0;
PaddingMode m_padding_mode;
};
struct CipherKey {
virtual ByteBuffer data() const = 0;
static bool is_valid_key_size(size_t) { return false; };
struct CipherKey {
virtual ByteBuffer data() const = 0;
static bool is_valid_key_size(size_t) { return false; };
virtual ~CipherKey() { }
virtual ~CipherKey() { }
protected:
virtual void expand_encrypt_key(const ByteBuffer& user_key, size_t bits) = 0;
virtual void expand_decrypt_key(const ByteBuffer& user_key, size_t bits) = 0;
size_t bits { 0 };
};
protected:
virtual void expand_encrypt_key(const ByteBuffer& user_key, size_t bits) = 0;
virtual void expand_decrypt_key(const ByteBuffer& user_key, size_t bits) = 0;
size_t bits { 0 };
};
template <typename KeyT = CipherKey, typename BlockT = CipherBlock>
class Cipher {
public:
using KeyType = KeyT;
using BlockType = BlockT;
template<typename KeyT = CipherKey, typename BlockT = CipherBlock>
class Cipher {
public:
using KeyType = KeyT;
using BlockType = BlockT;
explicit Cipher<KeyT, BlockT>(PaddingMode mode)
: m_padding_mode(mode)
{
}
explicit Cipher<KeyT, BlockT>(PaddingMode mode)
: m_padding_mode(mode)
{
}
virtual const KeyType& key() const = 0;
virtual KeyType& key() = 0;
virtual const KeyType& key() const = 0;
virtual KeyType& key() = 0;
static size_t block_size() { return BlockType::block_size(); }
static size_t block_size() { return BlockType::block_size(); }
PaddingMode padding_mode() const { return m_padding_mode; }
PaddingMode padding_mode() const { return m_padding_mode; }
virtual void encrypt_block(const BlockType& in, BlockType& out) = 0;
virtual void decrypt_block(const BlockType& in, BlockType& out) = 0;
virtual void encrypt_block(const BlockType& in, BlockType& out) = 0;
virtual void decrypt_block(const BlockType& in, BlockType& out) = 0;
virtual String class_name() const = 0;
virtual String class_name() const = 0;
private:
PaddingMode m_padding_mode;
};
private:
PaddingMode m_padding_mode;
};
}
}

View file

@ -36,6 +36,8 @@ namespace Cipher {
template <typename T>
class CBC : public Mode<T> {
public:
constexpr static size_t IVSizeInBits = 128;
virtual ~CBC() {}
template <typename... Args>
explicit constexpr CBC<T>(Args... args)
@ -51,6 +53,8 @@ namespace Cipher {
return builder.build();
}
virtual size_t IV_length() const { return IVSizeInBits / 8; }
virtual Optional<ByteBuffer> encrypt(const ByteBuffer& in, ByteBuffer& out, Optional<ByteBuffer> ivec = {}) override
{
auto length = in.size();

View file

@ -32,88 +32,90 @@
namespace Crypto {
namespace Cipher {
template <typename T>
class Mode {
public:
virtual ~Mode() {}
template<typename T>
class Mode {
public:
virtual ~Mode() { }
// FIXME: Somehow communicate that encrypt returns the last initialization vector (if the mode supports it)
virtual Optional<ByteBuffer> encrypt(const ByteBuffer& in, ByteBuffer& out, Optional<ByteBuffer> ivec = {}) = 0;
virtual void decrypt(const ByteBuffer& in, ByteBuffer& out, Optional<ByteBuffer> ivec = {}) = 0;
// FIXME: Somehow communicate that encrypt returns the last initialization vector (if the mode supports it)
virtual Optional<ByteBuffer> encrypt(const ByteBuffer& in, ByteBuffer& out, Optional<ByteBuffer> ivec = {}) = 0;
virtual void decrypt(const ByteBuffer& in, ByteBuffer& out, Optional<ByteBuffer> ivec = {}) = 0;
const T& cipher() const { return m_cipher; }
virtual size_t IV_length() const = 0;
ByteBuffer create_aligned_buffer(size_t input_size) const
{
size_t remainder = (input_size + T::block_size()) % T::block_size();
if (remainder == 0)
return ByteBuffer::create_uninitialized(input_size);
else
return ByteBuffer::create_uninitialized(input_size + T::block_size() - remainder);
}
const T& cipher() const { return m_cipher; }
virtual String class_name() const = 0;
T& cipher() { return m_cipher; }
ByteBuffer create_aligned_buffer(size_t input_size) const
{
size_t remainder = (input_size + T::block_size()) % T::block_size();
if (remainder == 0)
return ByteBuffer::create_uninitialized(input_size);
else
return ByteBuffer::create_uninitialized(input_size + T::block_size() - remainder);
}
protected:
virtual void prune_padding(ByteBuffer& data)
{
auto size = data.size();
switch (m_cipher.padding_mode()) {
case PaddingMode::CMS: {
auto maybe_padding_length = data[size - 1];
if (maybe_padding_length >= T::block_size()) {
// cannot be padding (the entire block cannot be padding)
virtual String class_name() const = 0;
T& cipher() { return m_cipher; }
protected:
virtual void prune_padding(ByteBuffer& data)
{
auto size = data.size();
switch (m_cipher.padding_mode()) {
case PaddingMode::CMS: {
auto maybe_padding_length = data[size - 1];
if (maybe_padding_length >= T::block_size()) {
// cannot be padding (the entire block cannot be padding)
return;
}
for (auto i = maybe_padding_length; i > 0; --i) {
if (data[size - i] != maybe_padding_length) {
// not padding, part of data
return;
}
for (auto i = maybe_padding_length; i > 0; --i) {
if (data[size - i] != maybe_padding_length) {
// not padding, part of data
return;
}
}
data.trim(size - maybe_padding_length);
break;
}
case PaddingMode::RFC5246: {
auto maybe_padding_length = data[size - 1];
if (maybe_padding_length >= T::block_size() - 1) {
// cannot be padding (the entire block cannot be padding)
data.trim(size - maybe_padding_length);
break;
}
case PaddingMode::RFC5246: {
auto maybe_padding_length = data[size - 1];
if (maybe_padding_length >= T::block_size() - 1) {
// cannot be padding (the entire block cannot be padding)
return;
}
// FIXME: If we want to constant-time operations, this loop should not stop
for (auto i = maybe_padding_length; i > 0; --i) {
if (data[size - i - 1] != maybe_padding_length) {
// note that this is likely invalid padding
return;
}
// FIXME: If we want to constant-time operations, this loop should not stop
for (auto i = maybe_padding_length; i > 0; --i) {
if (data[size - i - 1] != maybe_padding_length) {
// note that this is likely invalid padding
return;
}
}
data.trim(size - maybe_padding_length - 1);
break;
}
case PaddingMode::Null: {
while (data[size - 1] == 0)
--size;
data.trim(size);
break;
}
default:
// FIXME: support other padding modes
ASSERT_NOT_REACHED();
break;
}
data.trim(size - maybe_padding_length - 1);
break;
}
// FIXME: Somehow add a reference version of this
template <typename... Args>
Mode(Args... args)
: m_cipher(args...)
{
case PaddingMode::Null: {
while (data[size - 1] == 0)
--size;
data.trim(size);
break;
}
default:
// FIXME: support other padding modes
ASSERT_NOT_REACHED();
break;
}
}
private:
T m_cipher;
};
// FIXME: Somehow add a reference version of this
template<typename... Args>
Mode(Args... args)
: m_cipher(args...)
{
}
private:
T m_cipher;
};
}
}