53 lines
977 B
C
53 lines
977 B
C
#include <rand.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <sha256.h>
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char __rand_state[32];
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int __rand_seeded = 0;
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void rand_init_auto()
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{
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int f = open("/dev/random", O_RDONLY);
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read( f, __rand_state, 32 );
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close(f);
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__rand_seeded = 1;
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}
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void rand_init_seeded(long seed)
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{
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memset( __rand_state, 0x00, 32 );
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memcpy(__rand_state, &seed, 8 );
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sha256(__rand_state, 32, __rand_state);
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sha256(__rand_state, 32, __rand_state);
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sha256(__rand_state, 32, __rand_state);
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sha256(__rand_state, 32, __rand_state);
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__rand_seeded = 1;
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}
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void rand_get_bytes(char *dst, int length)
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{
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if (!__rand_seeded)
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rand_init_auto();
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while (length > 0)
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{
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int l = length > 32 ? 32 : length;
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sha256(__rand_state, 32, __rand_state);
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memcpy( dst, __rand_state, l);
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length -= l;
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dst += l;
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}
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sha256(__rand_state, 32, __rand_state);
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}
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