pwdbased.h

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// pwdbased.h - originally written and placed in the public domain by Wei Dai
//              Cutover to KeyDerivationFunction interface by Uri Blumenthal
//              Marcel Raad and Jeffrey Walton in March 2018.

/// \file pwdbased.h
/// \brief Password based key derivation functions

#ifndef CRYPTOPP_PWDBASED_H
#define CRYPTOPP_PWDBASED_H

#include "cryptlib.h"
#include "hrtimer.h"
#include "integer.h"
#include "argnames.h"
#include "algparam.h"
#include "hmac.h"

NAMESPACE_BEGIN(CryptoPP)

// ******************** PBKDF1 ********************

/// \brief PBKDF1 from PKCS #5
/// \tparam T a HashTransformation class
template <class T>
class PKCS5_PBKDF1 : public PasswordBasedKeyDerivationFunction
{
public:
    virtual ~PKCS5_PBKDF1() {}

    static std::string StaticAlgorithmName () {
        const std::string name(std::string("PBKDF1(") +
            std::string(T::StaticAlgorithmName()) + std::string(")"));
        return name;
    }

    // KeyDerivationFunction interface
    std::string AlgorithmName() const {
        return StaticAlgorithmName();
    }

    // KeyDerivationFunction interface
    size_t MaxDerivedKeyLength() const {
        return static_cast<size_t>(T::DIGESTSIZE);
    }

    // KeyDerivationFunction interface
    size_t GetValidDerivedLength(size_t keylength) const;

    // KeyDerivationFunction interface
    virtual size_t DeriveKey(byte *derived, size_t derivedLen, const byte *secret, size_t secretLen,
        const NameValuePairs& params = g_nullNameValuePairs) const;

    /// \brief Derive a key from a secret seed
    /// \param derived the derived output buffer
    /// \param derivedLen the size of the derived buffer, in bytes
    /// \param purpose a purpose byte
    /// \param secret the seed input buffer
    /// \param secretLen the size of the secret buffer, in bytes
    /// \param salt the salt input buffer
    /// \param saltLen the size of the salt buffer, in bytes
    /// \param iterations the number of iterations
    /// \param timeInSeconds the in seconds
    /// \returns the number of iterations performed
    /// \throws InvalidDerivedLength if <tt>derivedLen</tt> is invalid for the scheme
    /// \details DeriveKey() provides a standard interface to derive a key from
    ///   a seed and other parameters. Each class that derives from KeyDerivationFunction
    ///   provides an overload that accepts most parameters used by the derivation function.
    /// \details If <tt>timeInSeconds</tt> is <tt>&gt; 0.0</tt> then DeriveKey will run for
    ///   the specified amount of time. If <tt>timeInSeconds</tt> is <tt>0.0</tt> then DeriveKey
    ///   will run for the specified number of iterations.
    /// \details PKCS #5 says PBKDF1 should only take 8-byte salts. This implementation
    ///   allows salts of any length.
    size_t DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *secret, size_t secretLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds=0) const;

protected:
    // KeyDerivationFunction interface
    const Algorithm & GetAlgorithm() const {
        return *this;
    }
};

template <class T>
size_t PKCS5_PBKDF1<T>::GetValidDerivedLength(size_t keylength) const
{
    if (keylength > MaxDerivedLength())
        return MaxDerivedLength();
    return keylength;
}

template <class T>
size_t PKCS5_PBKDF1<T>::DeriveKey(byte *derived, size_t derivedLen,
    const byte *secret, size_t secretLen, const NameValuePairs& params) const
{
    CRYPTOPP_ASSERT(secret /*&& secretLen*/);
    CRYPTOPP_ASSERT(derived && derivedLen);
    CRYPTOPP_ASSERT(derivedLen <= MaxDerivedLength());

    byte purpose = (byte)params.GetIntValueWithDefault("Purpose", 0);
    unsigned int iterations = (unsigned int)params.GetIntValueWithDefault("Iterations", 1);

    double timeInSeconds = 0.0f;
    (void)params.GetValue("TimeInSeconds", timeInSeconds);

    ConstByteArrayParameter salt;
    (void)params.GetValue(Name::Salt(), salt);

    return DeriveKey(derived, derivedLen, purpose, secret, secretLen, salt.begin(), salt.size(), iterations, timeInSeconds);
}

template <class T>
size_t PKCS5_PBKDF1<T>::DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *secret, size_t secretLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds) const
{
    CRYPTOPP_ASSERT(secret /*&& secretLen*/);
    CRYPTOPP_ASSERT(derived && derivedLen);
    CRYPTOPP_ASSERT(derivedLen <= MaxDerivedLength());
    CRYPTOPP_ASSERT(iterations > 0 || timeInSeconds > 0);
    CRYPTOPP_UNUSED(purpose);

    ThrowIfInvalidDerivedLength(derivedLen);

    // Business logic
    if (!iterations) { iterations = 1; }

    T hash;
    hash.Update(secret, secretLen);
    hash.Update(salt, saltLen);

    SecByteBlock buffer(hash.DigestSize());
    hash.Final(buffer);

    unsigned int i;
    ThreadUserTimer timer;

    if (timeInSeconds)
        timer.StartTimer();

    for (i=1; i<iterations || (timeInSeconds && (i%128!=0 || timer.ElapsedTimeAsDouble() < timeInSeconds)); i++)
        hash.CalculateDigest(buffer, buffer, buffer.size());

    memcpy(derived, buffer, derivedLen);
    return i;
}

// ******************** PKCS5_PBKDF2_HMAC ********************

/// \brief PBKDF2 from PKCS #5
/// \tparam T a HashTransformation class
template <class T>
class PKCS5_PBKDF2_HMAC : public PasswordBasedKeyDerivationFunction
{
public:
    virtual ~PKCS5_PBKDF2_HMAC() {}

    static std::string StaticAlgorithmName () {
        const std::string name(std::string("PBKDF2_HMAC(") +
            std::string(T::StaticAlgorithmName()) + std::string(")"));
        return name;
    }

    // KeyDerivationFunction interface
    std::string AlgorithmName() const {
        return StaticAlgorithmName();
    }

    // KeyDerivationFunction interface
    // should multiply by T::DIGESTSIZE, but gets overflow that way
    size_t MaxDerivedKeyLength() const {
        return 0xffffffffU;
    }

    // KeyDerivationFunction interface
    size_t GetValidDerivedLength(size_t keylength) const;

    // KeyDerivationFunction interface
    size_t DeriveKey(byte *derived, size_t derivedLen, const byte *secret, size_t secretLen,
        const NameValuePairs& params = g_nullNameValuePairs) const;

    /// \brief Derive a key from a secret seed
    /// \param derived the derived output buffer
    /// \param derivedLen the size of the derived buffer, in bytes
    /// \param purpose a purpose byte
    /// \param secret the seed input buffer
    /// \param secretLen the size of the secret buffer, in bytes
    /// \param salt the salt input buffer
    /// \param saltLen the size of the salt buffer, in bytes
    /// \param iterations the number of iterations
    /// \param timeInSeconds the in seconds
    /// \returns the number of iterations performed
    /// \throws InvalidDerivedLength if <tt>derivedLen</tt> is invalid for the scheme
    /// \details DeriveKey() provides a standard interface to derive a key from
    ///   a seed and other parameters. Each class that derives from KeyDerivationFunction
    ///   provides an overload that accepts most parameters used by the derivation function.
    /// \details If <tt>timeInSeconds</tt> is <tt>&gt; 0.0</tt> then DeriveKey will run for
    ///   the specified amount of time. If <tt>timeInSeconds</tt> is <tt>0.0</tt> then DeriveKey
    ///   will run for the specified number of iterations.
    size_t DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *secret, size_t secretLen,
        const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds=0) const;

protected:
    // KeyDerivationFunction interface
    const Algorithm & GetAlgorithm() const {
        return *this;
    }
};

template <class T>
size_t PKCS5_PBKDF2_HMAC<T>::GetValidDerivedLength(size_t keylength) const
{
    if (keylength > MaxDerivedLength())
        return MaxDerivedLength();
    return keylength;
}

template <class T>
size_t PKCS5_PBKDF2_HMAC<T>::DeriveKey(byte *derived, size_t derivedLen,
    const byte *secret, size_t secretLen, const NameValuePairs& params) const
{
    CRYPTOPP_ASSERT(secret /*&& secretLen*/);
    CRYPTOPP_ASSERT(derived && derivedLen);
    CRYPTOPP_ASSERT(derivedLen <= MaxDerivedLength());

    byte purpose = (byte)params.GetIntValueWithDefault("Purpose", 0);
    unsigned int iterations = (unsigned int)params.GetIntValueWithDefault("Iterations", 1);

    double timeInSeconds = 0.0f;
    (void)params.GetValue("TimeInSeconds", timeInSeconds);

    ConstByteArrayParameter salt;
    (void)params.GetValue(Name::Salt(), salt);

    return DeriveKey(derived, derivedLen, purpose, secret, secretLen, salt.begin(), salt.size(), iterations, timeInSeconds);
}

template <class T>
size_t PKCS5_PBKDF2_HMAC<T>::DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *secret, size_t secretLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds) const
{
    CRYPTOPP_ASSERT(secret /*&& secretLen*/);
    CRYPTOPP_ASSERT(derived && derivedLen);
    CRYPTOPP_ASSERT(derivedLen <= MaxDerivedLength());
    CRYPTOPP_ASSERT(iterations > 0 || timeInSeconds > 0);
    CRYPTOPP_UNUSED(purpose);

    ThrowIfInvalidDerivedLength(derivedLen);

    // Business logic
    if (!iterations) { iterations = 1; }

    HMAC<T> hmac(secret, secretLen);
    SecByteBlock buffer(hmac.DigestSize());
    ThreadUserTimer timer;

    unsigned int i=1;
    while (derivedLen > 0)
    {
        hmac.Update(salt, saltLen);
        unsigned int j;
        for (j=0; j<4; j++)
        {
            byte b = byte(i >> ((3-j)*8));
            hmac.Update(&b, 1);
        }
        hmac.Final(buffer);

#if CRYPTOPP_MSC_VERSION
        const size_t segmentLen = STDMIN(derivedLen, buffer.size());
        memcpy_s(derived, segmentLen, buffer, segmentLen);
#else
        const size_t segmentLen = STDMIN(derivedLen, buffer.size());
        memcpy(derived, buffer, segmentLen);
#endif

        if (timeInSeconds)
        {
            timeInSeconds = timeInSeconds / ((derivedLen + buffer.size() - 1) / buffer.size());
            timer.StartTimer();
        }

        for (j=1; j<iterations || (timeInSeconds && (j%128!=0 || timer.ElapsedTimeAsDouble() < timeInSeconds)); j++)
        {
            hmac.CalculateDigest(buffer, buffer, buffer.size());
            xorbuf(derived, buffer, segmentLen);
        }

        if (timeInSeconds)
        {
            iterations = j;
            timeInSeconds = 0;
        }

        derived += segmentLen;
        derivedLen -= segmentLen;
        i++;
    }

    return iterations;
}

// ******************** PKCS12_PBKDF ********************

/// \brief PBKDF from PKCS #12, appendix B
/// \tparam T a HashTransformation class
template <class T>
class PKCS12_PBKDF : public PasswordBasedKeyDerivationFunction
{
public:
    virtual ~PKCS12_PBKDF() {}

    static std::string StaticAlgorithmName () {
        const std::string name(std::string("PBKDF_PKCS12(") +
            std::string(T::StaticAlgorithmName()) + std::string(")"));
        return name;
    }

    // KeyDerivationFunction interface
    std::string AlgorithmName() const {
        return StaticAlgorithmName();
    }

    // TODO - check this
    size_t MaxDerivedKeyLength() const {
        return static_cast<size_t>(-1);
    }

    // KeyDerivationFunction interface
    size_t GetValidDerivedLength(size_t keylength) const;

    // KeyDerivationFunction interface
    size_t DeriveKey(byte *derived, size_t derivedLen, const byte *secret, size_t secretLen,
        const NameValuePairs& params = g_nullNameValuePairs) const;

    /// \brief Derive a key from a secret seed
    /// \param derived the derived output buffer
    /// \param derivedLen the size of the derived buffer, in bytes
    /// \param purpose a purpose byte
    /// \param secret the seed input buffer
    /// \param secretLen the size of the secret buffer, in bytes
    /// \param salt the salt input buffer
    /// \param saltLen the size of the salt buffer, in bytes
    /// \param iterations the number of iterations
    /// \param timeInSeconds the in seconds
    /// \returns the number of iterations performed
    /// \throws InvalidDerivedLength if <tt>derivedLen</tt> is invalid for the scheme
    /// \details DeriveKey() provides a standard interface to derive a key from
    ///   a seed and other parameters. Each class that derives from KeyDerivationFunction
    ///   provides an overload that accepts most parameters used by the derivation function.
    /// \details If <tt>timeInSeconds</tt> is <tt>&gt; 0.0</tt> then DeriveKey will run for
    ///   the specified amount of time. If <tt>timeInSeconds</tt> is <tt>0.0</tt> then DeriveKey
    ///   will run for the specified number of iterations.
    size_t DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *secret, size_t secretLen,
        const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds) const;

protected:
    // KeyDerivationFunction interface
    const Algorithm & GetAlgorithm() const {
        return *this;
    }
};

template <class T>
size_t PKCS12_PBKDF<T>::GetValidDerivedLength(size_t keylength) const
{
    if (keylength > MaxDerivedLength())
        return MaxDerivedLength();
    return keylength;
}

template <class T>
size_t PKCS12_PBKDF<T>::DeriveKey(byte *derived, size_t derivedLen,
    const byte *secret, size_t secretLen, const NameValuePairs& params) const
{
    CRYPTOPP_ASSERT(secret /*&& secretLen*/);
    CRYPTOPP_ASSERT(derived && derivedLen);
    CRYPTOPP_ASSERT(derivedLen <= MaxDerivedLength());

    byte purpose = (byte)params.GetIntValueWithDefault("Purpose", 0);
    unsigned int iterations = (unsigned int)params.GetIntValueWithDefault("Iterations", 1);

    double timeInSeconds = 0.0f;
    (void)params.GetValue("TimeInSeconds", timeInSeconds);

    // NULL or 0 length salt OK
    ConstByteArrayParameter salt;
    (void)params.GetValue(Name::Salt(), salt);

    return DeriveKey(derived, derivedLen, purpose, secret, secretLen, salt.begin(), salt.size(), iterations, timeInSeconds);
}

template <class T>
size_t PKCS12_PBKDF<T>::DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *secret, size_t secretLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds) const
{
    CRYPTOPP_ASSERT(secret /*&& secretLen*/);
    CRYPTOPP_ASSERT(derived && derivedLen);
    CRYPTOPP_ASSERT(derivedLen <= MaxDerivedLength());
    CRYPTOPP_ASSERT(iterations > 0 || timeInSeconds > 0);

    ThrowIfInvalidDerivedLength(derivedLen);

    // Business logic
    if (!iterations) { iterations = 1; }

    const size_t v = T::BLOCKSIZE;  // v is in bytes rather than bits as in PKCS #12
    const size_t DLen = v, SLen = RoundUpToMultipleOf(saltLen, v);
    const size_t PLen = RoundUpToMultipleOf(secretLen, v), ILen = SLen + PLen;
    SecByteBlock buffer(DLen + SLen + PLen);
    byte *D = buffer, *S = buffer+DLen, *P = buffer+DLen+SLen, *I = S;

    memset(D, purpose, DLen);
    size_t i;
    for (i=0; i<SLen; i++)
        S[i] = salt[i % saltLen];
    for (i=0; i<PLen; i++)
        P[i] = secret[i % secretLen];

    T hash;
    SecByteBlock Ai(T::DIGESTSIZE), B(v);
    ThreadUserTimer timer;

    while (derivedLen > 0)
    {
        hash.CalculateDigest(Ai, buffer, buffer.size());

        if (timeInSeconds)
        {
            timeInSeconds = timeInSeconds / ((derivedLen + Ai.size() - 1) / Ai.size());
            timer.StartTimer();
        }

        for (i=1; i<iterations || (timeInSeconds && (i%128!=0 || timer.ElapsedTimeAsDouble() < timeInSeconds)); i++)
            hash.CalculateDigest(Ai, Ai, Ai.size());

        if (timeInSeconds)
        {
            iterations = (unsigned int)i;
            timeInSeconds = 0;
        }

        for (i=0; i<B.size(); i++)
            B[i] = Ai[i % Ai.size()];

        Integer B1(B, B.size());
        ++B1;
        for (i=0; i<ILen; i+=v)
            (Integer(I+i, v) + B1).Encode(I+i, v);

#if CRYPTOPP_MSC_VERSION
        const size_t segmentLen = STDMIN(derivedLen, Ai.size());
        memcpy_s(derived, segmentLen, Ai, segmentLen);
#else
        const size_t segmentLen = STDMIN(derivedLen, Ai.size());
        std::memcpy(derived, Ai, segmentLen);
#endif

        derived += segmentLen;
        derivedLen -= segmentLen;
    }

    return iterations;
}

NAMESPACE_END

#endif