242 lines
11 KiB
C++
242 lines
11 KiB
C++
// poly1305.h - written and placed in the public domain by Jeffrey Walton and Jean-Pierre Munch
|
|
// Based on Andy Polyakov's Base-2^26 scalar multiplication implementation.
|
|
// For more information, see https://www.openssl.org/~appro/cryptogams/.
|
|
|
|
// The library added Bernstein's Poly1305 classses at Crypto++ 6.0. The IETF
|
|
// uses a slightly different implementation than Bernstein, and the IETF
|
|
// classes were added at Crypto++ 8.1. We wanted to maintain ABI compatibility
|
|
// at the 8.1 release so the original Poly1305 classes were not disturbed.
|
|
// Instead new classes were added for IETF Poly1305. The back-end implementation
|
|
// shares code as expected, however.
|
|
|
|
/// \file poly1305.h
|
|
/// \brief Classes for Poly1305 message authentication code
|
|
/// \details Poly1305-AES is a state-of-the-art message-authentication code suitable for a wide
|
|
/// variety of applications. Poly1305-AES computes a 16-byte authenticator of a variable-length
|
|
/// message, using a 16-byte AES key, a 16-byte additional key, and a 16-byte nonce.
|
|
/// \details Crypto++ also supplies the IETF's version of Poly1305. It is a slightly different
|
|
/// algorithm than Bernstein's version.
|
|
/// \sa Daniel J. Bernstein <A HREF="http://cr.yp.to/mac/poly1305-20050329.pdf">The Poly1305-AES
|
|
/// Message-Authentication Code (20050329)</A>, <a href="http://tools.ietf.org/html/rfc8439">RFC
|
|
/// 8439, ChaCha20 and Poly1305 for IETF Protocols</a> and Andy Polyakov <A
|
|
/// HREF="http://www.openssl.org/blog/blog/2016/02/15/poly1305-revised/">Poly1305 Revised</A>
|
|
/// \since Poly1305 since Crypto++ 6.0, Poly1305TLS since Crypto++ 8.1
|
|
|
|
#ifndef CRYPTOPP_POLY1305_H
|
|
#define CRYPTOPP_POLY1305_H
|
|
|
|
#include "cryptlib.h"
|
|
#include "seckey.h"
|
|
#include "secblock.h"
|
|
#include "argnames.h"
|
|
#include "algparam.h"
|
|
|
|
NAMESPACE_BEGIN(CryptoPP)
|
|
|
|
////////////////////////////// Bernstein Poly1305 //////////////////////////////
|
|
|
|
/// \brief Poly1305 message authentication code base class
|
|
/// \tparam T BlockCipherDocumentation derived class with 16-byte key and 16-byte blocksize
|
|
/// \details Poly1305_Base is the base class of Bernstein's Poly1305 algorithm.
|
|
/// \since Crypto++ 6.0
|
|
template <class T>
|
|
class CRYPTOPP_NO_VTABLE Poly1305_Base : public FixedKeyLength<32, SimpleKeyingInterface::UNIQUE_IV, 16>, public MessageAuthenticationCode
|
|
{
|
|
CRYPTOPP_COMPILE_ASSERT(T::DEFAULT_KEYLENGTH == 16);
|
|
CRYPTOPP_COMPILE_ASSERT(T::BLOCKSIZE == 16);
|
|
|
|
public:
|
|
static std::string StaticAlgorithmName() {return std::string("Poly1305(") + T::StaticAlgorithmName() + ")";}
|
|
|
|
CRYPTOPP_CONSTANT(DIGESTSIZE=T::BLOCKSIZE)
|
|
CRYPTOPP_CONSTANT(BLOCKSIZE=T::BLOCKSIZE)
|
|
|
|
virtual ~Poly1305_Base() {}
|
|
Poly1305_Base() : m_idx(0), m_used(true) {}
|
|
|
|
void Resynchronize (const byte *iv, int ivLength=-1);
|
|
void GetNextIV (RandomNumberGenerator &rng, byte *iv);
|
|
|
|
void UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms);
|
|
void Update(const byte *input, size_t length);
|
|
void TruncatedFinal(byte *mac, size_t size);
|
|
void Restart();
|
|
|
|
unsigned int BlockSize() const {return BLOCKSIZE;}
|
|
unsigned int DigestSize() const {return DIGESTSIZE;}
|
|
|
|
std::string AlgorithmProvider() const;
|
|
|
|
protected:
|
|
// TODO: No longer needed. Remove at next major version bump
|
|
void HashBlocks(const byte *input, size_t length, word32 padbit);
|
|
void HashFinal(byte *mac, size_t length);
|
|
|
|
typename T::Encryption m_cipher;
|
|
|
|
// Accumulated hash, clamped r-key, and encrypted nonce
|
|
FixedSizeAlignedSecBlock<word32, 5> m_h;
|
|
FixedSizeAlignedSecBlock<word32, 4> m_r;
|
|
FixedSizeAlignedSecBlock<word32, 4> m_n;
|
|
|
|
// Accumulated message bytes and index
|
|
FixedSizeAlignedSecBlock<byte, BLOCKSIZE> m_acc, m_nk;
|
|
size_t m_idx;
|
|
|
|
// Track nonce reuse; assert in debug but continue
|
|
bool m_used;
|
|
};
|
|
|
|
/// \brief Poly1305 message authentication code
|
|
/// \tparam T class derived from BlockCipherDocumentation with 16-byte key and 16-byte blocksize
|
|
/// \details Poly1305-AES is a state-of-the-art message-authentication code suitable for a wide
|
|
/// variety of applications. Poly1305-AES computes a 16-byte authenticator of a variable-length
|
|
/// message, using a 16-byte AES key, a 16-byte additional key, and a 16-byte nonce.
|
|
/// \details The key is 32 bytes and a concatenation <tt>key = {k,s}</tt>, where
|
|
/// <tt>k</tt> is the AES key and <tt>r</tt> is additional key that gets clamped.
|
|
/// The key is clamped internally so there is no need to perform the operation
|
|
/// before setting the key.
|
|
/// \details Each message must have a unique security context, which means either the key or nonce
|
|
/// must be changed after each message. It can be accomplished in one of two ways. First, you
|
|
/// can create a new Poly1305 object each time its needed.
|
|
/// <pre> SecByteBlock key(32), nonce(16);
|
|
/// prng.GenerateBlock(key, key.size());
|
|
/// prng.GenerateBlock(nonce, nonce.size());
|
|
///
|
|
/// Poly1305<AES> poly1305(key, key.size(), nonce, nonce.size());
|
|
/// poly1305.Update(...);
|
|
/// poly1305.Final(...);</pre>
|
|
///
|
|
/// \details Second, you can create a Poly1305 object, reuse the key, and set a fresh nonce
|
|
/// for each message. The second and subsequent nonces can be generated using GetNextIV().
|
|
/// <pre> SecByteBlock key(32), nonce(16);
|
|
/// prng.GenerateBlock(key, key.size());
|
|
/// prng.GenerateBlock(nonce, nonce.size());
|
|
///
|
|
/// // First message
|
|
/// Poly1305<AES> poly1305(key, key.size());
|
|
/// poly1305.Resynchronize(nonce);
|
|
/// poly1305.Update(...);
|
|
/// poly1305.Final(...);
|
|
///
|
|
/// // Second message
|
|
/// poly1305.GetNextIV(prng, nonce);
|
|
/// poly1305.Resynchronize(nonce);
|
|
/// poly1305.Update(...);
|
|
/// poly1305.Final(...);
|
|
/// ...</pre>
|
|
/// \warning Each message must have a unique security context. The Poly1305 class does not
|
|
/// enforce a fresh key or nonce for each message. The source code will assert in debug
|
|
/// builds to alert of nonce reuse. No action is taken in release builds.
|
|
/// \sa Daniel J. Bernstein <A HREF="http://cr.yp.to/mac/poly1305-20050329.pdf">The Poly1305-AES
|
|
/// Message-Authentication Code (20050329)</A> and Andy Polyakov <A
|
|
/// HREF="http://www.openssl.org/blog/blog/2016/02/15/poly1305-revised/">Poly1305 Revised</A>
|
|
/// \since Crypto++ 6.0
|
|
template <class T>
|
|
class Poly1305 : public MessageAuthenticationCodeFinal<Poly1305_Base<T> >
|
|
{
|
|
public:
|
|
CRYPTOPP_CONSTANT(DEFAULT_KEYLENGTH=Poly1305_Base<T>::DEFAULT_KEYLENGTH)
|
|
|
|
/// \brief Construct a Poly1305
|
|
Poly1305() {}
|
|
|
|
/// \brief Construct a Poly1305
|
|
/// \param key a byte array used to key the cipher
|
|
/// \param keyLength the size of the byte array, in bytes
|
|
/// \param nonce a byte array used to key the cipher
|
|
/// \param nonceLength the size of the byte array, in bytes
|
|
/// \details The key is 32 bytes and a concatenation <tt>key = {k,s}</tt>, where
|
|
/// <tt>k</tt> is the AES key and <tt>r</tt> is additional key that gets clamped.
|
|
/// The key is clamped internally so there is no need to perform the operation
|
|
/// before setting the key.
|
|
/// \details Each message requires a unique security context. You can use GetNextIV()
|
|
/// and Resynchronize() to set a new nonce under a key for a message.
|
|
Poly1305(const byte *key, size_t keyLength=DEFAULT_KEYLENGTH, const byte *nonce=NULLPTR, size_t nonceLength=0)
|
|
{this->SetKey(key, keyLength, MakeParameters(Name::IV(), ConstByteArrayParameter(nonce, nonceLength)));}
|
|
};
|
|
|
|
////////////////////////////// IETF Poly1305 //////////////////////////////
|
|
|
|
/// \brief Poly1305-TLS message authentication code base class
|
|
/// \details Poly1305TLS_Base is the base class of the IETF's Poly1305 algorithm.
|
|
/// \since Crypto++ 8.1
|
|
class Poly1305TLS_Base : public FixedKeyLength<32>, public MessageAuthenticationCode
|
|
{
|
|
public:
|
|
static std::string StaticAlgorithmName() {return std::string("Poly1305TLS");}
|
|
CRYPTOPP_CONSTANT(DIGESTSIZE=16)
|
|
CRYPTOPP_CONSTANT(BLOCKSIZE=16)
|
|
|
|
virtual ~Poly1305TLS_Base() {}
|
|
Poly1305TLS_Base() {}
|
|
|
|
void UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms);
|
|
void Update(const byte *input, size_t length);
|
|
void TruncatedFinal(byte *mac, size_t size);
|
|
void Restart();
|
|
|
|
unsigned int BlockSize() const {return BLOCKSIZE;}
|
|
unsigned int DigestSize() const {return DIGESTSIZE;}
|
|
|
|
protected:
|
|
// Accumulated hash, clamped r-key, and encrypted nonce
|
|
FixedSizeAlignedSecBlock<word32, 5> m_h;
|
|
FixedSizeAlignedSecBlock<word32, 4> m_r;
|
|
FixedSizeAlignedSecBlock<word32, 4> m_n;
|
|
|
|
// Accumulated message bytes and index
|
|
FixedSizeAlignedSecBlock<byte, BLOCKSIZE> m_acc;
|
|
size_t m_idx;
|
|
};
|
|
|
|
/// \brief Poly1305-TLS message authentication code
|
|
/// \details This is the IETF's variant of Bernstein's Poly1305 from RFC 8439.
|
|
/// IETF Poly1305 is called Poly1305TLS in the Crypto++ library. It is
|
|
/// _slightly_ different from the Bernstein implementation. Poly1305-TLS
|
|
/// can be used for cipher suites
|
|
/// <tt>TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256</tt>,
|
|
/// <tt>TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256</tt>, and
|
|
/// <tt>TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256</tt>.
|
|
/// \details The key is 32 bytes and a concatenation <tt>key = {r,s}</tt>, where
|
|
/// <tt>r</tt> is additional key that gets clamped and <tt>s</tt> is the nonce.
|
|
/// The key is clamped internally so there is no need to perform the operation
|
|
/// before setting the key.
|
|
/// \details Each message must have a unique security context, which means the key
|
|
/// must be changed after each message. It can be accomplished in one of two ways.
|
|
/// First, you can create a new Poly1305 object with a new key each time its needed.
|
|
/// <pre> SecByteBlock key(32);
|
|
/// prng.GenerateBlock(key, key.size());
|
|
///
|
|
/// Poly1305TLS poly1305(key, key.size());
|
|
/// poly1305.Update(...);
|
|
/// poly1305.Final(...);</pre>
|
|
///
|
|
/// \details Second, you can create a Poly1305 object, and use a new key for each
|
|
/// message. The keys can be generated directly using a RandomNumberGenerator()
|
|
/// derived class.
|
|
/// <pre> SecByteBlock key(32);
|
|
/// prng.GenerateBlock(key, key.size());
|
|
///
|
|
/// // First message
|
|
/// Poly1305TLS poly1305(key, key.size());
|
|
/// poly1305.Update(...);
|
|
/// poly1305.Final(...);
|
|
///
|
|
/// // Second message
|
|
/// prng.GenerateBlock(key, key.size());
|
|
/// poly1305.SetKey(key, key.size());
|
|
/// poly1305.Update(...);
|
|
/// poly1305.Final(...);
|
|
/// ...</pre>
|
|
/// \warning Each message must have a unique security context. The Poly1305-TLS class
|
|
/// does not enforce a fresh key or nonce for each message.
|
|
/// \since Crypto++ 8.1
|
|
/// \sa MessageAuthenticationCode(), <a href="http://tools.ietf.org/html/rfc8439">RFC
|
|
/// 8439, ChaCha20 and Poly1305 for IETF Protocols</a>
|
|
DOCUMENTED_TYPEDEF(MessageAuthenticationCodeFinal<Poly1305TLS_Base>, Poly1305TLS)
|
|
|
|
NAMESPACE_END
|
|
|
|
#endif // CRYPTOPP_POLY1305_H
|