crashtest-r0ket/firmware/basic/ecc.h

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#ifndef _ECC_H_
#define _ECC_H_H
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#include <stdint.h>
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/******************************************************************************/
#define DEGREE 163 /* the degree of the field polynomial */
#define MARGIN 3 /* don't touch this */
#define NUMWORDS ((DEGREE + MARGIN + 31) / 32)
/* the following type will represent bit vectors of length (DEGREE+MARGIN) */
typedef uint32_t bitstr_t[NUMWORDS];
typedef bitstr_t elem_t; /* this type will represent field elements */
typedef bitstr_t exp_t;
int bitstr_parse_export(char *exp, const char *s);
void ECIES_setup(void);
void ECIES_encyptkeygen(uint8_t *px, uint8_t *py,
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uint8_t k1[16], uint8_t k2[16], uint8_t *Rx_exp, uint8_t *Ry_exp);
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int ECIES_decryptkeygen(uint8_t *rx, uint8_t *ry,
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uint8_t k1[16], uint8_t k2[16], const char *privkey);
#define ECIES_OVERHEAD (8 * NUMWORDS + 8)
/* ECIES encryption; the resulting cipher text message will be
(len + ECIES_OVERHEAD) bytes long */
void ECIES_encryption(char *msg, const char *text, int len,
const char *Px, const char *Py);
/* ECIES decryption */
int ECIES_decryption(char *text, const char *msg, int len,
const char *privkey);
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#define MACRO(A) do { A; } while(0)
#define MIN(a, b) ((a) < (b) ? (a) : (b))
/* some basic bit-manipulation routines that act on these vectors follow */
#define bitstr_getbit(A, idx) ((A[(idx) / 32] >> ((idx) % 32)) & 1)
#define bitstr_setbit(A, idx) MACRO( A[(idx) / 32] |= 1 << ((idx) % 32) )
#define bitstr_clrbit(A, idx) MACRO( A[(idx) / 32] &= ~(1 << ((idx) % 32)) )
#define bitstr_clear(A) MACRO( memset(A, 0, sizeof(bitstr_t)) )
#define bitstr_copy(A, B) MACRO( memcpy(A, B, sizeof(bitstr_t)) )
#define bitstr_swap(A, B) MACRO( bitstr_t h; \
bitstr_copy(h, A); bitstr_copy(A, B); bitstr_copy(B, h) )
#define bitstr_is_equal(A, B) (! memcmp(A, B, sizeof(bitstr_t)))
#define field_set1(A) MACRO( A[0] = 1; memset(A + 1, 0, sizeof(elem_t) - 4) )
#define point_is_zero(x, y) (bitstr_is_clear(x) && bitstr_is_clear(y))
#define point_set_zero(x, y) MACRO( bitstr_clear(x); bitstr_clear(y) )
#define point_copy(x1, y1, x2, y2) MACRO( bitstr_copy(x1, x2); \
bitstr_copy(y1, y2) )
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#endif