void autocorrelation_function::rearrange_image_to_acf_in(image_t& acf, const image_t* image) const { int H = height_/2; int W = width_/2; for (int i = 0; i <= H; ++i) { for (int j = 0; j <= W; ++j) { int acf_i; int acf_j; acf_i = H-1-i; acf_j = W-1-j; if (is_valid_idx(acf_i,acf_j)) { acf.at<float>(acf_i,acf_j) = image->at<float>(height_-1-i,width_-1-j); } acf_i = i+H; acf_j = j+W; if (is_valid_idx(acf_i,acf_j)) { acf.at<float>(acf_i,acf_j) = image->at<float>(i,j); } acf_i = H-1-i; acf_j = j+W; if (is_valid_idx(acf_i,acf_j)) { acf.at<float>(acf_i,acf_j) = image->at<float>(height_-1-i,j); } acf_i = i+H; acf_j = W-1-j; if (is_valid_idx(acf_i,acf_j)) { acf.at<float>(acf_i,acf_j) = image->at<float>(i,width_-1-j); } } } }
/** Verify an ECC signature @param sig The signature to verify @param siglen The length of the signature (octets) @param hash The hash (message digest) that was signed @param hashlen The length of the hash (octets) @param stat Result of signature, 1==valid, 0==invalid @param key The corresponding public ECC key @return CRYPT_OK if successful (even if the signature is not valid) */ int ecc_verify_hash(const unsigned char *sig, unsigned long siglen, const unsigned char *hash, unsigned long hashlen, int *stat, ecc_key *key) { ecc_point *mG, *mQ; mp_int r, s, v, w, u1, u2, e, p, m; mp_digit mp; int err; LTC_ARGCHK(sig != NULL); LTC_ARGCHK(hash != NULL); LTC_ARGCHK(stat != NULL); LTC_ARGCHK(key != NULL); /* default to invalid signature */ *stat = 0; /* is the IDX valid ? */ if (is_valid_idx(key->idx) != 1) { return CRYPT_PK_INVALID_TYPE; } /* allocate ints */ if ((err = mp_init_multi(&r, &s, &v, &w, &u1, &u2, &p, &e, &m, NULL)) != MP_OKAY) { return CRYPT_MEM; } /* allocate points */ mG = new_point(); mQ = new_point(); if (mQ == NULL || mG == NULL) { err = CRYPT_MEM; goto done; } /* parse header */ if ((err = der_decode_sequence_multi(sig, siglen, LTC_ASN1_INTEGER, 1UL, &r, LTC_ASN1_INTEGER, 1UL, &s, LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) { goto done; } /* get the order */ if ((err = mp_read_radix(&p, (char *)sets[key->idx].order, 64)) != MP_OKAY) { goto error; } /* get the modulus */ if ((err = mp_read_radix(&m, (char *)sets[key->idx].prime, 64)) != MP_OKAY) { goto error; } /* check for zero */ if (mp_iszero(&r) || mp_iszero(&s) || mp_cmp(&r, &p) != MP_LT || mp_cmp(&s, &p) != MP_LT) { err = CRYPT_INVALID_PACKET; goto done; } /* read hash */ if ((err = mp_read_unsigned_bin(&e, (unsigned char *)hash, (int)hashlen)) != MP_OKAY) { goto error; } /* w = s^-1 mod n */ if ((err = mp_invmod(&s, &p, &w)) != MP_OKAY) { goto error; } /* u1 = ew */ if ((err = mp_mulmod(&e, &w, &p, &u1)) != MP_OKAY) { goto error; } /* u2 = rw */ if ((err = mp_mulmod(&r, &w, &p, &u2)) != MP_OKAY) { goto error; } /* find mG = u1*G */ if ((err = mp_read_radix(&mG->x, (char *)sets[key->idx].Gx, 64)) != MP_OKAY) { goto error; } if ((err = mp_read_radix(&mG->y, (char *)sets[key->idx].Gy, 64)) != MP_OKAY) { goto error; } mp_set(&mG->z, 1); if ((err = ecc_mulmod(&u1, mG, mG, &m, 0)) != CRYPT_OK) { goto done; } /* find mQ = u2*Q */ if ((err = mp_copy(&key->pubkey.x, &mQ->x)) != MP_OKAY) { goto error; } if ((err = mp_copy(&key->pubkey.y, &mQ->y)) != MP_OKAY) { goto error; } if ((err = mp_copy(&key->pubkey.z, &mQ->z)) != MP_OKAY) { goto error; } if ((err = ecc_mulmod(&u2, mQ, mQ, &m, 0)) != CRYPT_OK) { goto done; } /* find the montgomery mp */ if ((err = mp_montgomery_setup(&m, &mp)) != MP_OKAY) { goto error; } /* add them */ if ((err = add_point(mQ, mG, mG, &m, mp)) != CRYPT_OK) { goto done; } /* reduce */ if ((err = ecc_map(mG, &m, mp)) != CRYPT_OK) { goto done; } /* v = X_x1 mod n */ if ((err = mp_mod(&mG->x, &p, &v)) != CRYPT_OK) { goto done; } /* does v == r */ if (mp_cmp(&v, &r) == MP_EQ) { *stat = 1; } /* clear up and return */ err = CRYPT_OK; goto done; error: err = mpi_to_ltc_error(err); done: del_point(mG); del_point(mQ); mp_clear_multi(&r, &s, &v, &w, &u1, &u2, &p, &e, &m, NULL); return err; }
/** Sign a message digest @param in The message digest to sign @param inlen The length of the digest @param out [out] The destination for the signature @param outlen [in/out] The max size and resulting size of the signature @param prng An active PRNG state @param wprng The index of the PRNG you wish to use @param key A private ECC key @return CRYPT_OK if successful */ int ecc_sign_hash(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen, prng_state *prng, int wprng, ecc_key *key) { ecc_key pubkey; mp_int r, s, e, p; int err; LTC_ARGCHK(in != NULL); LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); LTC_ARGCHK(key != NULL); /* is this a private key? */ if (key->type != PK_PRIVATE) { return CRYPT_PK_NOT_PRIVATE; } /* is the IDX valid ? */ if (is_valid_idx(key->idx) != 1) { return CRYPT_PK_INVALID_TYPE; } if ((err = prng_is_valid(wprng)) != CRYPT_OK) { return err; } /* get the hash and load it as a bignum into 'e' */ /* init the bignums */ if ((err = mp_init_multi(&r, &s, &p, &e, NULL)) != MP_OKAY) { ecc_free(&pubkey); err = mpi_to_ltc_error(err); goto LBL_ERR; } if ((err = mp_read_radix(&p, (char *)sets[key->idx].order, 64)) != MP_OKAY) { goto error; } if ((err = mp_read_unsigned_bin(&e, (unsigned char *)in, (int)inlen)) != MP_OKAY) { goto error; } /* make up a key and export the public copy */ for (;;) { if ((err = ecc_make_key(prng, wprng, ecc_get_size(key), &pubkey)) != CRYPT_OK) { return err; } /* find r = x1 mod n */ if ((err = mp_mod(&pubkey.pubkey.x, &p, &r)) != MP_OKAY) { goto error; } if (mp_iszero(&r)) { ecc_free(&pubkey); } else { /* find s = (e + xr)/k */ if ((err = mp_invmod(&pubkey.k, &p, &pubkey.k)) != MP_OKAY) { goto error; } /* k = 1/k */ if ((err = mp_mulmod(&key->k, &r, &p, &s)) != MP_OKAY) { goto error; } /* s = xr */ if ((err = mp_addmod(&e, &s, &p, &s)) != MP_OKAY) { goto error; } /* s = e + xr */ if ((err = mp_mulmod(&s, &pubkey.k, &p, &s)) != MP_OKAY) { goto error; } /* s = (e + xr)/k */ if (mp_iszero(&s)) { ecc_free(&pubkey); } else { break; } } } /* store as SEQUENCE { r, s -- integer } */ err = der_encode_sequence_multi(out, outlen, LTC_ASN1_INTEGER, 1UL, &r, LTC_ASN1_INTEGER, 1UL, &s, LTC_ASN1_EOL, 0UL, NULL); goto LBL_ERR; error: err = mpi_to_ltc_error(err); LBL_ERR: mp_clear_multi(&r, &s, &p, &e, NULL); ecc_free(&pubkey); return err; }
/** Sign a message digest using a DH private key @param in The data to sign @param inlen The length of the input (octets) @param out [out] The destination of the signature @param outlen [in/out] The max size and resulting size of the output @param prng An active PRNG state @param wprng The index of the PRNG desired @param key A private DH key @return CRYPT_OK if successful */ int dh_sign_hash(const unsigned char *in, unsigned long inlen, unsigned char *out, unsigned long *outlen, prng_state *prng, int wprng, dh_key *key) { mp_int a, b, k, m, g, p, p1, tmp; unsigned char *buf; unsigned long x, y; int err; LTC_ARGCHK(in != NULL); LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); LTC_ARGCHK(key != NULL); /* check parameters */ if (key->type != PK_PRIVATE) { return CRYPT_PK_NOT_PRIVATE; } if ((err = prng_is_valid(wprng)) != CRYPT_OK) { return err; } /* is the IDX valid ? */ if (is_valid_idx(key->idx) != 1) { return CRYPT_PK_INVALID_TYPE; } /* allocate ram for buf */ buf = XMALLOC(520); /* make up a random value k, * since the order of the group is prime * we need not check if gcd(k, r) is 1 */ if (prng_descriptor[wprng].read(buf, sets[key->idx].size, prng) != (unsigned long)(sets[key->idx].size)) { err = CRYPT_ERROR_READPRNG; goto LBL_ERR; } /* init bignums */ if ((err = mp_init_multi(&a, &b, &k, &m, &p, &g, &p1, &tmp, NULL)) != MP_OKAY) { err = mpi_to_ltc_error(err); goto LBL_ERR; } /* load k and m */ if ((err = mp_read_unsigned_bin(&m, (unsigned char *)in, inlen)) != MP_OKAY) { goto error; } if ((err = mp_read_unsigned_bin(&k, buf, sets[key->idx].size)) != MP_OKAY) { goto error; } /* load g, p and p1 */ if ((err = mp_read_radix(&g, sets[key->idx].base, 64)) != MP_OKAY) { goto error; } if ((err = mp_read_radix(&p, sets[key->idx].prime, 64)) != MP_OKAY) { goto error; } if ((err = mp_sub_d(&p, 1, &p1)) != MP_OKAY) { goto error; } if ((err = mp_div_2(&p1, &p1)) != MP_OKAY) { goto error; } /* p1 = (p-1)/2 */ /* now get a = g^k mod p */ if ((err = mp_exptmod(&g, &k, &p, &a)) != MP_OKAY) { goto error; } /* now find M = xa + kb mod p1 or just b = (M - xa)/k mod p1 */ if ((err = mp_invmod(&k, &p1, &k)) != MP_OKAY) { goto error; } /* k = 1/k mod p1 */ if ((err = mp_mulmod(&a, &key->x, &p1, &tmp)) != MP_OKAY) { goto error; } /* tmp = xa */ if ((err = mp_submod(&m, &tmp, &p1, &tmp)) != MP_OKAY) { goto error; } /* tmp = M - xa */ if ((err = mp_mulmod(&k, &tmp, &p1, &b)) != MP_OKAY) { goto error; } /* b = (M - xa)/k */ /* check for overflow */ if ((unsigned long)(PACKET_SIZE + 4 + 4 + mp_unsigned_bin_size(&a) + mp_unsigned_bin_size(&b)) > *outlen) { err = CRYPT_BUFFER_OVERFLOW; goto LBL_ERR; } /* store header */ y = PACKET_SIZE; /* now store them both (a,b) */ x = (unsigned long)mp_unsigned_bin_size(&a); STORE32L(x, out+y); y += 4; if ((err = mp_to_unsigned_bin(&a, out+y)) != MP_OKAY) { goto error; } y += x; x = (unsigned long)mp_unsigned_bin_size(&b); STORE32L(x, out+y); y += 4; if ((err = mp_to_unsigned_bin(&b, out+y)) != MP_OKAY) { goto error; } y += x; /* check if size too big */ if (*outlen < y) { err = CRYPT_BUFFER_OVERFLOW; goto LBL_ERR; } /* store header */ packet_store_header(out, PACKET_SECT_DH, PACKET_SUB_SIGNED); *outlen = y; err = CRYPT_OK; goto LBL_ERR; error: err = mpi_to_ltc_error(err); LBL_ERR: mp_clear_multi(&tmp, &p1, &g, &p, &m, &k, &b, &a, NULL); XFREE(buf); return err; }