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#include "hmac.h"
/* function doing the HMAC-SHA-1 calculation */
void hmac_sha1(const uint8_t* key, const uint32_t keysize, const uint8_t* msg, const uint32_t msgsize, uint8_t* output)
{
struct sha1 outer, inner;
uint8_t tmp;
sha1_reset(&outer);
sha1_reset(&inner);
uint32_t i;
for (i = 0; i < keysize; ++i)
{
tmp = key[i] ^ 0x5C;
sha1_input(&outer, &tmp, 1);
tmp = key[i] ^ 0x36;
sha1_input(&inner, &tmp, 1);
}
for (; i < 64; ++i)
{
tmp = 0x5C;
sha1_input(&outer, &tmp, 1);
tmp = 0x36;
sha1_input(&inner, &tmp, 1);
}
sha1_input(&inner, msg, msgsize);
sha1_result(&inner, output);
sha1_input(&outer, output, HMAC_SHA1_HASH_SIZE);
sha1_result(&outer, output);
}
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