ilibrary_authentication.h

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 //*****************************************************************************


 // Copyright 1986, 2014 NVIDIA Corporation. All rights reserved.


 //*****************************************************************************


 //*****************************************************************************


 

 #ifndef MI_NEURAYLIB_ILIBRARY_AUTHENTICATION_H


 #define MI_NEURAYLIB_ILIBRARY_AUTHENTICATION_H


 


 #include <mi/base/handle.h>


 #include <mi/base/interface_declare.h>


 #include <mi/neuraylib/ineuray.h>


 

 #ifdef MI_PLATFORM_WINDOWS


 #include <mi/base/miwindows.h>


 #else


 #include <sys/time.h>


 #include <cstdlib>


 #include <ctime>


 #endif


 


 #include <cstring>


 

 namespace mi {

 

 namespace neuraylib {

 

 class ILibrary_authenticator : public


     mi::base::Interface_declare<0x5a7d010a,0x2a65,0x43da,0x92,0xf2,0xcd,0xd9,0xc8,0x4b,0x10,0xd2>

 {

 public:

     inline static Sint32 authenticate(

         const INeuray* library,

         const char* vendor_key, Sint32 vendor_key_length,

         const char* secret_key, Sint32 secret_key_length);

 

     //  Returns a challenge from the library.


     //


     //  Asks the library for a challenge. The authentication process combines the challenge with the


     //  secret key and the vendor key to generate the correct response.


     //


     //  \note This method is internal and should not be called directly. Use the convenience method


     //        #authenticate() instead.


     //


     //  \param buffer          The library will store the challenge here.


     //  \param buffer_length   The actual size of the buffer. If the buffer is not big enough


     //                         generating the challenge generation will fail. Currently, the buffer


     //                         should be able to hold at least 32 bytes.


     //  \return                The necessary size of the needed buffer. The application needs to


     //                         check this value to determine whether its supplied buffer was big


     //                         enough, otherwise the challenge is not valid.


     virtual Sint32 get_challenge(char* buffer, Sint32 buffer_length) = 0;

 

     //  Submits the calculated response to a challenge.


     //


     //  In addition, the application has to provide a vendor key and a random salt. This is used to


     //  make attacks more difficult.


     //


     //  \note This method is internal and should not be called directly. Use the convenience method


     //        #authenticate() instead.


     //


     //  \param response          The calculated response.


     //  \param response_length   The size of the response.


     //  \param vendor_key        The vendor key assigned to the application writer.


     //  \param vendor_key_length The size of the vendor key.


     //  \param salt              A random salt. Should be a random array of bytes.


     //  \param salt_length       The size of the salt.


     virtual void submit_challenge_response(

         const char* response, Sint32 response_length,

         const char* vendor_key, Sint32 vendor_key_length,

         const char* salt, Sint32 salt_length) = 0;

 };

 

 namespace detail

 {

 // Generates a nounce.


 //


 // \param[out] out_buffer   The buffer for the nounce. Needs to be able to hold 32 bytes.


 static void generate_nounce( char* out_buffer);

 

 // Generates the response for a challenge, salt, and secret key.


 //


 // \param salt              The salt (32 bytes).


 // \param challenge         The challenge (32 bytes).


 // \param secret_key        The secret key used to calculate the response.


 // \param secret_key_length The size of the secret key.


 // \param[out] out_response The buffer for the response. Needs to be able to hold 32 bytes.


 static void calculate_response(

     const char* salt, const char* challenge,

     const char* secret_key, Sint32 secret_key_length, char* out_response);

 

 // Computes a SHA256 hash value.


 //


 // \param input           The input for which to compute the SHA256 hash value.


 // \param input_length    The size of the input.


 // \param[out] out_buffer The buffer for the SHA256 hash value. Needs to be able to hold 32 bytes.


 static void sha256( const char* input, int input_length, char* out_buffer);

 }

 

 inline Sint32 ILibrary_authenticator::authenticate(

     const INeuray* library,

     const char* vendor_key, Sint32 vendor_key_length,

     const char* secret_key, Sint32 secret_key_length)

 {

     if( !library)

         return -1;

 

     base::Handle<ILibrary_authenticator> authenticator(

         library->get_api_component<ILibrary_authenticator>());

     if( !authenticator.is_valid_interface())

         return -2;

 

     char challenge[32];

     memset( &challenge[0], 0, 32);

     if( authenticator->get_challenge( challenge, static_cast<Sint32>( sizeof( challenge)))

         > static_cast<Sint32>( sizeof( challenge)))

         return -3;

 

     char salt[32];

     detail::generate_nounce( salt);

 

     char response[32];

     detail::calculate_response( salt, challenge, secret_key, secret_key_length, response);

 

     authenticator->submit_challenge_response(

         response, static_cast<Sint32>( sizeof( response)), vendor_key, vendor_key_length, 

         salt, static_cast<Sint32>( sizeof( salt)));

     return 0;

 }

 

 namespace detail

 {

 

 void calculate_response(

     const char* salt, const char* challenge,

     const char* secret_key, Sint32 secret_key_length, char* out_response)

 {

     if( (secret_key_length < 0) || (secret_key_length > 1024*10))

         return;

     // salt = 32 bytes, challenge = 32 bytes


     int total_len = 32 + 32 + secret_key_length;

     char* buffer = new char[total_len];

     memcpy( buffer, salt, 32);

     memcpy( buffer + 32, challenge, 32);

     memcpy( buffer + 64, secret_key, secret_key_length);

     sha256( buffer, total_len, out_response);

     delete[] buffer;

 }

 

 void generate_nounce( char* out_buffer)

 {

     if( out_buffer == 0)

         return;

     Uint64 number = 0;

 #ifdef MI_PLATFORM_WINDOWS


     srand( GetTickCount());

     LARGE_INTEGER tmp;

     QueryPerformanceCounter( &tmp);

     number += tmp.QuadPart + GetCurrentProcessId() + GetTickCount();

 #else


     srand( static_cast<unsigned>( time(  0)));

     struct timeval tv;

     gettimeofday( &tv, 0);

     number += tv.tv_sec + tv.tv_usec;

 #endif


     char buf[sizeof( Uint32) + 3*sizeof( Uint64)] = {0};

     int r = rand();

     memcpy( buf, &r, sizeof( Uint32));

     memcpy( buf + sizeof( Uint32), &number, sizeof( Uint64));

     memcpy( buf + sizeof( Uint32) + sizeof( Uint64), &number, sizeof( Uint64));

     number += rand();

     memcpy( buf + sizeof( Uint32) + 2*sizeof( Uint64), &number, sizeof( Uint64));

     sha256( const_cast<const char*>( buf), static_cast<Sint32>( sizeof( buf)), out_buffer);

 }

 

 // Table of round constants.


 // First 32 bits of the fractional parts of the cube roots of the first 64 primes 2..311


 static const Uint32 sha256_constants[] = {

     0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,

     0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,

     0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,

     0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,

     0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,

     0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,

     0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,

     0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2

 };

 

 // Reverses the byte order of the bytes of \p x


 static Uint32 flip32( Uint32 x)

 {

     return ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) |

             (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24));

 }

 

 // Rotates the bits of \p x to the right by \p y bits


 static Uint32 rightrotate( Uint32 x, Uint32 y)

 {

     return (( x >> y) | (x << (32-y)));

 }

 

 void sha256( const char* input, int input_length, char* out_buffer)

 {

     if( (input_length <= 0) || (input == 0) || (out_buffer == 0))

        return;

 

     // First 32 bits of the fractional parts of the square roots of the first 8 primes 2..19


     Uint32 state[] = {0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,

                       0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};

 

     // k is the number of '0' bits >= 0 such that the resulting message length is 448 (mod 512)


     int k = 448 - (input_length * 8 + 1) % 512;

     if( k < 0)

         k += 512;

 

     int pos = 0;

     for( int chunk = 0; k != 0; ++chunk) {

 

         Uint32 W[64] = {0};

         Uint8* ptr = reinterpret_cast<Uint8*>( W);

         int to_copy = input_length - pos;

         to_copy = to_copy > 64 ? 64 : to_copy;

         if( to_copy > 0) {

             memcpy( ptr, input + pos, to_copy);

             pos += to_copy;

         }

 

         // If we are at the end of input message


         if( pos == input_length) {

             // If we still have not padded and have space to add a 1, add it


             if( (k > 0) && (pos % 64 < 64) && (pos/64 == chunk))

                 ptr[pos%64] |= static_cast<Uint8>( 0x80);

             // If we can pad and still have space to add the length, add it


             if( (pos*8 + 1 + k) - (chunk*512) <= 448) {

                 Uint64 value = input_length * 8;

                 ptr = reinterpret_cast<Uint8*>(&W[14]);

                 ptr[0] = static_cast<Uint8>((value >> 56) & 0xff);

                 ptr[1] = static_cast<Uint8>((value >> 48) & 0xff);

                 ptr[2] = static_cast<Uint8>((value >> 40) & 0xff);

                 ptr[3] = static_cast<Uint8>((value >> 32) & 0xff);

                 ptr[4] = static_cast<Uint8>((value >> 24) & 0xff);

                 ptr[5] = static_cast<Uint8>((value >> 16) & 0xff);

                 ptr[6] = static_cast<Uint8>((value >>  8) & 0xff);

                 ptr[7] = static_cast<Uint8>( value        & 0xff);

                 k = 0;

             }

         }

 

         // Flip to big endian


         for( int i = 0; i < 16; ++i)

             W[i] = flip32( W[i]);

 

         // Extend the sixteen 32-bit words into 64 32-bit words


         for( Uint32 i = 16; i < 64; ++i) {

             Uint32 s0 = rightrotate( W[i-15], 7) ^ rightrotate( W[i-15], 18) ^ (W[i-15] >> 3);

             Uint32 s1 = rightrotate( W[i-2], 17) ^ rightrotate( W[i- 2], 19) ^ (W[i-2] >> 10);

             W[i] = W[i-16] + s0 + W[i-7] + s1;

         }

 

         // Initialize hash value for this chunk


         Uint32 a = state[0];

         Uint32 b = state[1];

         Uint32 c = state[2];

         Uint32 d = state[3];

         Uint32 e = state[4];

         Uint32 f = state[5];

         Uint32 g = state[6];

         Uint32 h = state[7];

 

         for( Uint32 j = 0; j < 64; ++j) {

             Uint32 s0  = rightrotate( a, 2) ^ rightrotate( a, 13) ^ rightrotate( a, 22);

             Uint32 maj = (a & b) ^ (a & c) ^ (b & c);

             Uint32 t2  = s0 + maj;

             Uint32 s1  = rightrotate( e, 6) ^ rightrotate( e, 11) ^ rightrotate( e, 25);

             Uint32 ch  = (e & f) ^ ((~e) & g);

             Uint32 t1  = h + s1 + ch + sha256_constants[j] + W[j];

 

             h = g; g = f; f = e; e = d + t1;

             d = c; c = b; b = a; a = t1 + t2;

         }

 

         // Add this chunk's hash value to result so far


         state[0] += a; state[1] += b; state[2] += c; state[3] += d;

         state[4] += e; state[5] += f; state[6] += g; state[7] += h;

     }

 

     // Flip to little endian


     for( int i = 0; i < 8; ++i)

         state[i] = flip32( state[i]);

 

     memcpy( out_buffer, reinterpret_cast<char*>( state), 32);

 }

 

 } // namespace detail


  // end group mi_neuray_configuration


 

 } // namespace neuraylib


 

 } // namespace mi


 

 #endif // MI_NEURAYLIB_ILIBRARY_AUTHENTICATION_H