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comparison ecc.c @ 143:5d99163f7e32 libtomcrypt-orig

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import of libtomcrypt 0.99
author Matt Johnston <matt@ucc.asn.au>
date Sun, 19 Dec 2004 11:34:45 +0000
parents 7faae8f46238
children
comparison
equal deleted inserted replaced
15:6362d3854bb4 143:5d99163f7e32
16 */ 16 */
17 17
18 #include "mycrypt.h" 18 #include "mycrypt.h"
19 19
20 #ifdef MECC 20 #ifdef MECC
21
22 /* size of our temp buffers for exported keys */
23 #define ECC_BUF_SIZE 160
24
25 /* max private key size */
26 #define ECC_MAXSIZE 66
21 27
22 /* This holds the key settings. ***MUST*** be organized by size from smallest to largest. */ 28 /* This holds the key settings. ***MUST*** be organized by size from smallest to largest. */
23 static const struct { 29 static const struct {
24 int size; 30 int size;
25 char *name, *prime, *B, *order, *Gx, *Gy; 31 char *name, *prime, *B, *order, *Gx, *Gy;
217 mp_clear_multi(&tx, &ty, &x, &y, &p, &pp, &r, &B, &tmp1, &tmp2, NULL); 223 mp_clear_multi(&tx, &ty, &x, &y, &p, &pp, &r, &B, &tmp1, &tmp2, NULL);
218 } 224 }
219 225
220 #endif 226 #endif
221 227
222
223
224
225 static int is_valid_idx(int n) 228 static int is_valid_idx(int n)
226 { 229 {
227 int x; 230 int x;
228 231
229 for (x = 0; sets[x].size != 0; x++); 232 for (x = 0; sets[x].size != 0; x++);
366 369
367 /* perform R = kG where k == integer and G == ecc_point */ 370 /* perform R = kG where k == integer and G == ecc_point */
368 static int ecc_mulmod(mp_int *k, ecc_point *G, ecc_point *R, mp_int *modulus) 371 static int ecc_mulmod(mp_int *k, ecc_point *G, ecc_point *R, mp_int *modulus)
369 { 372 {
370 ecc_point *tG, *M[8]; 373 ecc_point *tG, *M[8];
371 int i, j, err; 374 int i, j, err;
372 mp_int mu; 375 mp_int mu;
373 mp_digit buf; 376 mp_digit buf;
374 int first, bitbuf, bitcpy, bitcnt, mode, digidx; 377 int first, bitbuf, bitcpy, bitcnt, mode, digidx;
375 378
376 /* init barrett reduction */ 379 /* init barrett reduction */
377 if ((err = mp_init(&mu)) != MP_OKAY) { 380 if ((err = mp_init(&mu)) != MP_OKAY) {
378 return mpi_to_ltc_error(err); 381 return mpi_to_ltc_error(err);
379 } 382 }
593 } 596 }
594 } 597 }
595 598
596 int ecc_make_key(prng_state *prng, int wprng, int keysize, ecc_key *key) 599 int ecc_make_key(prng_state *prng, int wprng, int keysize, ecc_key *key)
597 { 600 {
598 int x, err; 601 int x, err;
599 ecc_point *base; 602 ecc_point *base;
600 mp_int prime; 603 mp_int prime;
601 unsigned char buf[128]; 604 unsigned char *buf;
602 605
603 _ARGCHK(key != NULL); 606 _ARGCHK(key != NULL);
604 607
605 /* good prng? */ 608 /* good prng? */
606 if ((err = prng_is_valid(wprng)) != CRYPT_OK) { 609 if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
608 } 611 }
609 612
610 /* find key size */ 613 /* find key size */
611 for (x = 0; (keysize > sets[x].size) && (sets[x].size != 0); x++); 614 for (x = 0; (keysize > sets[x].size) && (sets[x].size != 0); x++);
612 keysize = sets[x].size; 615 keysize = sets[x].size;
616 _ARGCHK(keysize <= ECC_MAXSIZE);
613 617
614 if (sets[x].size == 0) { 618 if (sets[x].size == 0) {
615 return CRYPT_INVALID_KEYSIZE; 619 return CRYPT_INVALID_KEYSIZE;
616 } 620 }
617 key->idx = x; 621 key->idx = x;
618 622
623 /* allocate ram */
624 base = NULL;
625 buf = XMALLOC(ECC_MAXSIZE);
626 if (buf == NULL) {
627 return CRYPT_MEM;
628 }
629
619 /* make up random string */ 630 /* make up random string */
620 if (prng_descriptor[wprng].read(buf, (unsigned long)keysize, prng) != (unsigned long)keysize) { 631 if (prng_descriptor[wprng].read(buf, (unsigned long)keysize, prng) != (unsigned long)keysize) {
621 return CRYPT_ERROR_READPRNG; 632 err = CRYPT_ERROR_READPRNG;
633 goto __ERR2;
622 } 634 }
623 635
624 /* setup the key variables */ 636 /* setup the key variables */
625 if ((err = mp_init_multi(&key->pubkey.x, &key->pubkey.y, &key->k, &prime, NULL)) != MP_OKAY) { 637 if ((err = mp_init_multi(&key->pubkey.x, &key->pubkey.y, &key->k, &prime, NULL)) != MP_OKAY) {
626 return mpi_to_ltc_error(err); 638 err = mpi_to_ltc_error(err);
639 goto __ERR;
627 } 640 }
628 base = new_point(); 641 base = new_point();
629 if (base == NULL) { 642 if (base == NULL) {
630 mp_clear_multi(&key->pubkey.x, &key->pubkey.y, &key->k, &prime, NULL); 643 mp_clear_multi(&key->pubkey.x, &key->pubkey.y, &key->k, &prime, NULL);
631 return CRYPT_MEM; 644 err = CRYPT_MEM;
645 goto __ERR;
632 } 646 }
633 647
634 /* read in the specs for this key */ 648 /* read in the specs for this key */
635 if ((err = mp_read_radix(&prime, (char *)sets[key->idx].prime, 64)) != MP_OKAY) { goto error; } 649 if ((err = mp_read_radix(&prime, (char *)sets[key->idx].prime, 64)) != MP_OKAY) { goto error; }
636 if ((err = mp_read_radix(&base->x, (char *)sets[key->idx].Gx, 64)) != MP_OKAY) { goto error; } 650 if ((err = mp_read_radix(&base->x, (char *)sets[key->idx].Gx, 64)) != MP_OKAY) { goto error; }
637 if ((err = mp_read_radix(&base->y, (char *)sets[key->idx].Gy, 64)) != MP_OKAY) { goto error; } 651 if ((err = mp_read_radix(&base->y, (char *)sets[key->idx].Gy, 64)) != MP_OKAY) { goto error; }
638 if ((err = mp_read_unsigned_bin(&key->k, (unsigned char *)buf, keysize)) != MP_OKAY) { goto error; } 652 if ((err = mp_read_unsigned_bin(&key->k, (unsigned char *)buf, keysize)) != MP_OKAY) { goto error; }
639 653
640 /* make the public key */ 654 /* make the public key */
641 if ((err = ecc_mulmod(&key->k, base, &key->pubkey, &prime)) != CRYPT_OK) { goto done; } 655 if ((err = ecc_mulmod(&key->k, base, &key->pubkey, &prime)) != CRYPT_OK) { goto __ERR; }
642 key->type = PK_PRIVATE; 656 key->type = PK_PRIVATE;
643 657
644 /* shrink key */ 658 /* shrink key */
645 if ((err = mp_shrink(&key->k)) != MP_OKAY) { goto error; } 659 if ((err = mp_shrink(&key->k)) != MP_OKAY) { goto error; }
646 if ((err = mp_shrink(&key->pubkey.x)) != MP_OKAY) { goto error; } 660 if ((err = mp_shrink(&key->pubkey.x)) != MP_OKAY) { goto error; }
647 if ((err = mp_shrink(&key->pubkey.y)) != MP_OKAY) { goto error; } 661 if ((err = mp_shrink(&key->pubkey.y)) != MP_OKAY) { goto error; }
648 662
649 /* free up ram */ 663 /* free up ram */
650 err = CRYPT_OK; 664 err = CRYPT_OK;
651 goto done; 665 goto __ERR;
652 error: 666 error:
653 err = mpi_to_ltc_error(err); 667 err = mpi_to_ltc_error(err);
654 done: 668 __ERR:
655 del_point(base); 669 del_point(base);
656 mp_clear(&prime); 670 mp_clear(&prime);
671 __ERR2:
657 #ifdef CLEAN_STACK 672 #ifdef CLEAN_STACK
658 zeromem(buf, sizeof(buf)); 673 zeromem(buf, ECC_MAXSIZE);
659 #endif 674 #endif
675
676 XFREE(buf);
677
660 return err; 678 return err;
661 } 679 }
662 680
663 void ecc_free(ecc_key *key) 681 void ecc_free(ecc_key *key)
664 { 682 {