mirror of
https://github.com/bitcoin/bitcoin.git
synced 2025-04-29 23:09:44 -04:00
Split ChaCha20 into aligned/unaligned variants
This commit is contained in:
Pieter Wuille
parent
ceb74b844c
commit
e37bcaa0a6
2 changed files with 97 additions and 45 deletions
|
|
@ -8,6 +8,7 @@
|
|||
#include <crypto/common.h>
|
||||
#include <crypto/chacha20.h>
|
||||
|
||||
#include <algorithm>
|
||||
#include <string.h>
|
||||
|
||||
constexpr static inline uint32_t rotl32(uint32_t v, int c) { return (v << c) | (v >> (32 - c)); }
|
||||
|
|
@ -23,7 +24,7 @@ constexpr static inline uint32_t rotl32(uint32_t v, int c) { return (v << c) | (
|
|||
static const unsigned char sigma[] = "expand 32-byte k";
|
||||
static const unsigned char tau[] = "expand 16-byte k";
|
||||
|
||||
void ChaCha20::SetKey(const unsigned char* k, size_t keylen)
|
||||
void ChaCha20Aligned::SetKey(const unsigned char* k, size_t keylen)
|
||||
{
|
||||
const unsigned char *constants;
|
||||
|
||||
|
|
@ -51,37 +52,34 @@ void ChaCha20::SetKey(const unsigned char* k, size_t keylen)
|
|||
input[15] = 0;
|
||||
}
|
||||
|
||||
ChaCha20::ChaCha20()
|
||||
ChaCha20Aligned::ChaCha20Aligned()
|
||||
{
|
||||
memset(input, 0, sizeof(input));
|
||||
}
|
||||
|
||||
ChaCha20::ChaCha20(const unsigned char* k, size_t keylen)
|
||||
ChaCha20Aligned::ChaCha20Aligned(const unsigned char* k, size_t keylen)
|
||||
{
|
||||
SetKey(k, keylen);
|
||||
}
|
||||
|
||||
void ChaCha20::SetIV(uint64_t iv)
|
||||
void ChaCha20Aligned::SetIV(uint64_t iv)
|
||||
{
|
||||
input[14] = iv;
|
||||
input[15] = iv >> 32;
|
||||
}
|
||||
|
||||
void ChaCha20::Seek(uint64_t pos)
|
||||
void ChaCha20Aligned::Seek(uint64_t pos)
|
||||
{
|
||||
input[12] = pos;
|
||||
input[13] = pos >> 32;
|
||||
}
|
||||
|
||||
void ChaCha20::Keystream(unsigned char* c, size_t bytes)
|
||||
inline void ChaCha20Aligned::Keystream64(unsigned char* c, size_t blocks)
|
||||
{
|
||||
uint32_t x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
|
||||
uint32_t j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15;
|
||||
unsigned char *ctarget = nullptr;
|
||||
unsigned char tmp[64];
|
||||
unsigned int i;
|
||||
|
||||
if (!bytes) return;
|
||||
if (!blocks) return;
|
||||
|
||||
j0 = input[0];
|
||||
j1 = input[1];
|
||||
|
|
@ -101,10 +99,6 @@ void ChaCha20::Keystream(unsigned char* c, size_t bytes)
|
|||
j15 = input[15];
|
||||
|
||||
for (;;) {
|
||||
if (bytes < 64) {
|
||||
ctarget = c;
|
||||
c = tmp;
|
||||
}
|
||||
x0 = j0;
|
||||
x1 = j1;
|
||||
x2 = j2;
|
||||
|
|
@ -171,28 +165,22 @@ void ChaCha20::Keystream(unsigned char* c, size_t bytes)
|
|||
WriteLE32(c + 56, x14);
|
||||
WriteLE32(c + 60, x15);
|
||||
|
||||
if (bytes <= 64) {
|
||||
if (bytes < 64) {
|
||||
for (i = 0;i < bytes;++i) ctarget[i] = c[i];
|
||||
}
|
||||
if (blocks == 1) {
|
||||
input[12] = j12;
|
||||
input[13] = j13;
|
||||
return;
|
||||
}
|
||||
bytes -= 64;
|
||||
blocks -= 1;
|
||||
c += 64;
|
||||
}
|
||||
}
|
||||
|
||||
void ChaCha20::Crypt(const unsigned char* m, unsigned char* c, size_t bytes)
|
||||
inline void ChaCha20Aligned::Crypt64(const unsigned char* m, unsigned char* c, size_t blocks)
|
||||
{
|
||||
uint32_t x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
|
||||
uint32_t j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15;
|
||||
unsigned char *ctarget = nullptr;
|
||||
unsigned char tmp[64];
|
||||
unsigned int i;
|
||||
|
||||
if (!bytes) return;
|
||||
if (!blocks) return;
|
||||
|
||||
j0 = input[0];
|
||||
j1 = input[1];
|
||||
|
|
@ -212,14 +200,6 @@ void ChaCha20::Crypt(const unsigned char* m, unsigned char* c, size_t bytes)
|
|||
j15 = input[15];
|
||||
|
||||
for (;;) {
|
||||
if (bytes < 64) {
|
||||
// if m has fewer than 64 bytes available, copy m to tmp and
|
||||
// read from tmp instead
|
||||
for (i = 0;i < bytes;++i) tmp[i] = m[i];
|
||||
m = tmp;
|
||||
ctarget = c;
|
||||
c = tmp;
|
||||
}
|
||||
x0 = j0;
|
||||
x1 = j1;
|
||||
x2 = j2;
|
||||
|
|
@ -303,16 +283,48 @@ void ChaCha20::Crypt(const unsigned char* m, unsigned char* c, size_t bytes)
|
|||
WriteLE32(c + 56, x14);
|
||||
WriteLE32(c + 60, x15);
|
||||
|
||||
if (bytes <= 64) {
|
||||
if (bytes < 64) {
|
||||
for (i = 0;i < bytes;++i) ctarget[i] = c[i];
|
||||
}
|
||||
if (blocks == 1) {
|
||||
input[12] = j12;
|
||||
input[13] = j13;
|
||||
return;
|
||||
}
|
||||
bytes -= 64;
|
||||
blocks -= 1;
|
||||
c += 64;
|
||||
m += 64;
|
||||
}
|
||||
}
|
||||
|
||||
void ChaCha20::Keystream(unsigned char* c, size_t bytes)
|
||||
{
|
||||
if (!bytes) return;
|
||||
if (bytes >= 64) {
|
||||
size_t blocks = bytes / 64;
|
||||
m_aligned.Keystream64(c, blocks);
|
||||
c += blocks * 64;
|
||||
bytes -= blocks * 64;
|
||||
}
|
||||
if (bytes) {
|
||||
unsigned char buffer[64];
|
||||
m_aligned.Keystream64(buffer, 1);
|
||||
memcpy(c, buffer, bytes);
|
||||
}
|
||||
}
|
||||
|
||||
void ChaCha20::Crypt(const unsigned char* m, unsigned char* c, size_t bytes)
|
||||
{
|
||||
if (!bytes) return;
|
||||
if (bytes >= 64) {
|
||||
size_t blocks = bytes / 64;
|
||||
m_aligned.Crypt64(m, c, blocks);
|
||||
c += blocks * 64;
|
||||
m += blocks * 64;
|
||||
bytes -= blocks * 64;
|
||||
}
|
||||
if (bytes) {
|
||||
unsigned char buffer[64];
|
||||
m_aligned.Keystream64(buffer, 1);
|
||||
for (unsigned i = 0; i < bytes; i++) {
|
||||
c[i] = m[i] ^ buffer[i];
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -8,19 +8,59 @@
|
|||
#include <cstdlib>
|
||||
#include <stdint.h>
|
||||
|
||||
/** A class for ChaCha20 256-bit stream cipher developed by Daniel J. Bernstein
|
||||
https://cr.yp.to/chacha/chacha-20080128.pdf */
|
||||
class ChaCha20
|
||||
// classes for ChaCha20 256-bit stream cipher developed by Daniel J. Bernstein
|
||||
// https://cr.yp.to/chacha/chacha-20080128.pdf */
|
||||
|
||||
/** ChaCha20 cipher that only operates on multiples of 64 bytes. */
|
||||
class ChaCha20Aligned
|
||||
{
|
||||
private:
|
||||
uint32_t input[16];
|
||||
|
||||
public:
|
||||
ChaCha20();
|
||||
ChaCha20(const unsigned char* key, size_t keylen);
|
||||
void SetKey(const unsigned char* key, size_t keylen); //!< set key with flexible keylength; 256bit recommended */
|
||||
void SetIV(uint64_t iv); // set the 64bit nonce
|
||||
void Seek(uint64_t pos); // set the 64bit block counter
|
||||
ChaCha20Aligned();
|
||||
|
||||
/** Initialize a cipher with specified key (see SetKey for arguments). */
|
||||
ChaCha20Aligned(const unsigned char* key, size_t keylen);
|
||||
|
||||
/** set key with flexible keylength (16 or 32 bytes; 32 recommended). */
|
||||
void SetKey(const unsigned char* key, size_t keylen);
|
||||
|
||||
/** set the 64-bit nonce. */
|
||||
void SetIV(uint64_t iv);
|
||||
|
||||
/** set the 64bit block counter (pos seeks to byte position 64*pos). */
|
||||
void Seek(uint64_t pos);
|
||||
|
||||
/** outputs the keystream of size <64*blocks> into <c> */
|
||||
void Keystream64(unsigned char* c, size_t blocks);
|
||||
|
||||
/** enciphers the message <input> of length <64*blocks> and write the enciphered representation into <output>
|
||||
* Used for encryption and decryption (XOR)
|
||||
*/
|
||||
void Crypt64(const unsigned char* input, unsigned char* output, size_t blocks);
|
||||
};
|
||||
|
||||
/** Unrestricted ChaCha20 cipher. Seeks forward to a multiple of 64 bytes after every operation. */
|
||||
class ChaCha20
|
||||
{
|
||||
private:
|
||||
ChaCha20Aligned m_aligned;
|
||||
|
||||
public:
|
||||
ChaCha20() = default;
|
||||
|
||||
/** Initialize a cipher with specified key (see SetKey for arguments). */
|
||||
ChaCha20(const unsigned char* key, size_t keylen) : m_aligned(key, keylen) {}
|
||||
|
||||
/** set key with flexible keylength (16 or 32 bytes; 32 recommended). */
|
||||
void SetKey(const unsigned char* key, size_t keylen) { m_aligned.SetKey(key, keylen); }
|
||||
|
||||
/** set the 64-bit nonce. */
|
||||
void SetIV(uint64_t iv) { m_aligned.SetIV(iv); }
|
||||
|
||||
/** set the 64bit block counter (pos seeks to byte position 64*pos). */
|
||||
void Seek(uint64_t pos) { m_aligned.Seek(pos); }
|
||||
|
||||
/** outputs the keystream of size <bytes> into <c> */
|
||||
void Keystream(unsigned char* c, size_t bytes);
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue