Add tinycrypt 0.2.8
Signed-off-by: Fabio Utzig <utzig@apache.org>
diff --git a/ext/tinycrypt/lib/source/ecc_dsa.c b/ext/tinycrypt/lib/source/ecc_dsa.c
index dd84a18..064dfe5 100644
--- a/ext/tinycrypt/lib/source/ecc_dsa.c
+++ b/ext/tinycrypt/lib/source/ecc_dsa.c
@@ -1,7 +1,30 @@
/* ec_dsa.c - TinyCrypt implementation of EC-DSA */
+/* Copyright (c) 2014, Kenneth MacKay
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.*/
+
/*
- * Copyright (C) 2015 by Intel Corporation, All Rights Reserved.
+ * Copyright (C) 2017 by Intel Corporation, All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
@@ -32,84 +55,241 @@
#include <tinycrypt/constants.h>
#include <tinycrypt/ecc.h>
+#include <tinycrypt/ecc_dsa.h>
-extern uint32_t curve_n[NUM_ECC_DIGITS];
-extern EccPoint curve_G;
-extern uint32_t curve_nb[NUM_ECC_DIGITS + 1];
+#if default_RNG_defined
+static uECC_RNG_Function g_rng_function = &default_CSPRNG;
+#else
+static uECC_RNG_Function g_rng_function = 0;
+#endif
-int32_t ecdsa_sign(uint32_t r[NUM_ECC_DIGITS], uint32_t s[NUM_ECC_DIGITS],
- uint32_t p_privateKey[NUM_ECC_DIGITS], uint32_t p_random[NUM_ECC_DIGITS],
- uint32_t p_hash[NUM_ECC_DIGITS])
+static void bits2int(uECC_word_t *native, const uint8_t *bits,
+ unsigned bits_size, uECC_Curve curve)
{
+ unsigned num_n_bytes = BITS_TO_BYTES(curve->num_n_bits);
+ unsigned num_n_words = BITS_TO_WORDS(curve->num_n_bits);
+ int shift;
+ uECC_word_t carry;
+ uECC_word_t *ptr;
- uint32_t k[NUM_ECC_DIGITS], tmp[NUM_ECC_DIGITS];
- EccPoint p_point;
- EccPointJacobi P;
-
- if (vli_isZero(p_random)) {
- return TC_CRYPTO_FAIL; /* The random number must not be 0. */
+ if (bits_size > num_n_bytes) {
+ bits_size = num_n_bytes;
}
- vli_set(k, p_random);
-
- vli_sub(tmp, k, curve_n, NUM_ECC_DIGITS);
- vli_cond_set(k, k, tmp, vli_cmp(curve_n, k, NUM_ECC_DIGITS) == 1);
-
- /* tmp = k * G */
- EccPoint_mult_safe(&P, &curve_G, k);
- EccPoint_toAffine(&p_point, &P);
-
- /* r = x1 (mod n) */
- vli_set(r, p_point.x);
- if (vli_cmp(curve_n, r, NUM_ECC_DIGITS) != 1) {
- vli_sub(r, r, curve_n, NUM_ECC_DIGITS);
+ uECC_vli_clear(native, num_n_words);
+ uECC_vli_bytesToNative(native, bits, bits_size);
+ if (bits_size * 8 <= (unsigned)curve->num_n_bits) {
+ return;
+ }
+ shift = bits_size * 8 - curve->num_n_bits;
+ carry = 0;
+ ptr = native + num_n_words;
+ while (ptr-- > native) {
+ uECC_word_t temp = *ptr;
+ *ptr = (temp >> shift) | carry;
+ carry = temp << (uECC_WORD_BITS - shift);
}
- if (vli_isZero(r)) {
- return TC_CRYPTO_FAIL; /* If r == 0, fail (need a different random number). */
+ /* Reduce mod curve_n */
+ if (uECC_vli_cmp_unsafe(curve->n, native, num_n_words) != 1) {
+ uECC_vli_sub(native, native, curve->n, num_n_words);
}
-
- vli_modMult(s, r, p_privateKey, curve_n, curve_nb); /* s = r*d */
- vli_modAdd(s, p_hash, s, curve_n); /* s = e + r*d */
- vli_modInv(k, k, curve_n, curve_nb); /* k = 1 / k */
- vli_modMult(s, s, k, curve_n, curve_nb); /* s = (e + r*d) / k */
-
- return TC_CRYPTO_SUCCESS;
}
-int32_t ecdsa_verify(EccPoint *p_publicKey, uint32_t p_hash[NUM_ECC_DIGITS],
- uint32_t r[NUM_ECC_DIGITS], uint32_t s[NUM_ECC_DIGITS])
+int uECC_sign_with_k(const uint8_t *private_key, const uint8_t *message_hash,
+ unsigned hash_size, uECC_word_t *k, uint8_t *signature,
+ uECC_Curve curve)
{
- uint32_t u1[NUM_ECC_DIGITS], u2[NUM_ECC_DIGITS];
- uint32_t z[NUM_ECC_DIGITS];
- EccPointJacobi P, R;
- EccPoint p_point;
+ uECC_word_t tmp[NUM_ECC_WORDS];
+ uECC_word_t s[NUM_ECC_WORDS];
+ uECC_word_t *k2[2] = {tmp, s};
+ uECC_word_t p[NUM_ECC_WORDS * 2];
+ uECC_word_t carry;
+ wordcount_t num_words = curve->num_words;
+ wordcount_t num_n_words = BITS_TO_WORDS(curve->num_n_bits);
+ bitcount_t num_n_bits = curve->num_n_bits;
- if (vli_isZero(r) || vli_isZero(s)) {
- return TC_CRYPTO_FAIL; /* r, s must not be 0. */
+ /* Make sure 0 < k < curve_n */
+ if (uECC_vli_isZero(k, num_words) ||
+ uECC_vli_cmp(curve->n, k, num_n_words) != 1) {
+ return 0;
}
- if ((vli_cmp(curve_n, r, NUM_ECC_DIGITS) != 1) ||
- (vli_cmp(curve_n, s, NUM_ECC_DIGITS) != 1)) {
- return TC_CRYPTO_FAIL; /* r, s must be < n. */
+ carry = regularize_k(k, tmp, s, curve);
+ EccPoint_mult(p, curve->G, k2[!carry], 0, num_n_bits + 1, curve);
+ if (uECC_vli_isZero(p, num_words)) {
+ return 0;
+ }
+
+ /* If an RNG function was specified, get a random number
+ to prevent side channel analysis of k. */
+ if (!g_rng_function) {
+ uECC_vli_clear(tmp, num_n_words);
+ tmp[0] = 1;
+ }
+ else if (!uECC_generate_random_int(tmp, curve->n, num_n_words)) {
+ return 0;
+ }
+
+ /* Prevent side channel analysis of uECC_vli_modInv() to determine
+ bits of k / the private key by premultiplying by a random number */
+ uECC_vli_modMult(k, k, tmp, curve->n, num_n_words); /* k' = rand * k */
+ uECC_vli_modInv(k, k, curve->n, num_n_words); /* k = 1 / k' */
+ uECC_vli_modMult(k, k, tmp, curve->n, num_n_words); /* k = 1 / k */
+
+ uECC_vli_nativeToBytes(signature, curve->num_bytes, p); /* store r */
+
+ /* tmp = d: */
+ uECC_vli_bytesToNative(tmp, private_key, BITS_TO_BYTES(curve->num_n_bits));
+
+ s[num_n_words - 1] = 0;
+ uECC_vli_set(s, p, num_words);
+ uECC_vli_modMult(s, tmp, s, curve->n, num_n_words); /* s = r*d */
+
+ bits2int(tmp, message_hash, hash_size, curve);
+ uECC_vli_modAdd(s, tmp, s, curve->n, num_n_words); /* s = e + r*d */
+ uECC_vli_modMult(s, s, k, curve->n, num_n_words); /* s = (e + r*d) / k */
+ if (uECC_vli_numBits(s, num_n_words) > (bitcount_t)curve->num_bytes * 8) {
+ return 0;
+ }
+
+ uECC_vli_nativeToBytes(signature + curve->num_bytes, curve->num_bytes, s);
+ return 1;
+}
+
+int uECC_sign(const uint8_t *private_key, const uint8_t *message_hash,
+ unsigned hash_size, uint8_t *signature, uECC_Curve curve)
+{
+ uECC_word_t _random[2*NUM_ECC_WORDS];
+ uECC_word_t k[NUM_ECC_WORDS];
+ uECC_word_t tries;
+
+ for (tries = 0; tries < uECC_RNG_MAX_TRIES; ++tries) {
+ /* Generating _random uniformly at random: */
+ uECC_RNG_Function rng_function = uECC_get_rng();
+ if (!rng_function ||
+ !rng_function((uint8_t *)_random, 2*NUM_ECC_WORDS*uECC_WORD_SIZE)) {
+ return 0;
+ }
+
+ // computing k as modular reduction of _random (see FIPS 186.4 B.5.1):
+ uECC_vli_mmod(k, _random, curve->n, BITS_TO_WORDS(curve->num_n_bits));
+
+ if (uECC_sign_with_k(private_key, message_hash, hash_size, k, signature,
+ curve)) {
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static bitcount_t smax(bitcount_t a, bitcount_t b)
+{
+ return (a > b ? a : b);
+}
+
+int uECC_verify(const uint8_t *public_key, const uint8_t *message_hash,
+ unsigned hash_size, const uint8_t *signature,
+ uECC_Curve curve)
+{
+
+ uECC_word_t u1[NUM_ECC_WORDS], u2[NUM_ECC_WORDS];
+ uECC_word_t z[NUM_ECC_WORDS];
+ uECC_word_t sum[NUM_ECC_WORDS * 2];
+ uECC_word_t rx[NUM_ECC_WORDS];
+ uECC_word_t ry[NUM_ECC_WORDS];
+ uECC_word_t tx[NUM_ECC_WORDS];
+ uECC_word_t ty[NUM_ECC_WORDS];
+ uECC_word_t tz[NUM_ECC_WORDS];
+ const uECC_word_t *points[4];
+ const uECC_word_t *point;
+ bitcount_t num_bits;
+ bitcount_t i;
+
+ uECC_word_t _public[NUM_ECC_WORDS * 2];
+ uECC_word_t r[NUM_ECC_WORDS], s[NUM_ECC_WORDS];
+ wordcount_t num_words = curve->num_words;
+ wordcount_t num_n_words = BITS_TO_WORDS(curve->num_n_bits);
+
+ rx[num_n_words - 1] = 0;
+ r[num_n_words - 1] = 0;
+ s[num_n_words - 1] = 0;
+
+ uECC_vli_bytesToNative(_public, public_key, curve->num_bytes);
+ uECC_vli_bytesToNative(_public + num_words, public_key + curve->num_bytes,
+ curve->num_bytes);
+ uECC_vli_bytesToNative(r, signature, curve->num_bytes);
+ uECC_vli_bytesToNative(s, signature + curve->num_bytes, curve->num_bytes);
+
+ /* r, s must not be 0. */
+ if (uECC_vli_isZero(r, num_words) || uECC_vli_isZero(s, num_words)) {
+ return 0;
+ }
+
+ /* r, s must be < n. */
+ if (uECC_vli_cmp_unsafe(curve->n, r, num_n_words) != 1 ||
+ uECC_vli_cmp_unsafe(curve->n, s, num_n_words) != 1) {
+ return 0;
}
/* Calculate u1 and u2. */
- vli_modInv(z, s, curve_n, curve_nb); /* Z = s^-1 */
- vli_modMult(u1, p_hash, z, curve_n, curve_nb); /* u1 = e/s */
- vli_modMult(u2, r, z, curve_n, curve_nb); /* u2 = r/s */
+ uECC_vli_modInv(z, s, curve->n, num_n_words); /* z = 1/s */
+ u1[num_n_words - 1] = 0;
+ bits2int(u1, message_hash, hash_size, curve);
+ uECC_vli_modMult(u1, u1, z, curve->n, num_n_words); /* u1 = e/s */
+ uECC_vli_modMult(u2, r, z, curve->n, num_n_words); /* u2 = r/s */
- /* calculate P = u1*G + u2*Q */
- EccPoint_mult_unsafe(&P, &curve_G, u1);
- EccPoint_mult_unsafe(&R, p_publicKey, u2);
- EccPoint_add(&P, &R);
- EccPoint_toAffine(&p_point, &P);
+ /* Calculate sum = G + Q. */
+ uECC_vli_set(sum, _public, num_words);
+ uECC_vli_set(sum + num_words, _public + num_words, num_words);
+ uECC_vli_set(tx, curve->G, num_words);
+ uECC_vli_set(ty, curve->G + num_words, num_words);
+ uECC_vli_modSub(z, sum, tx, curve->p, num_words); /* z = x2 - x1 */
+ XYcZ_add(tx, ty, sum, sum + num_words, curve);
+ uECC_vli_modInv(z, z, curve->p, num_words); /* z = 1/z */
+ apply_z(sum, sum + num_words, z, curve);
- /* Accept only if P.x == r. */
- if (!vli_sub(z, p_point.x, curve_n, NUM_ECC_DIGITS)) {
- vli_set(p_point.x, z);
+ /* Use Shamir's trick to calculate u1*G + u2*Q */
+ points[0] = 0;
+ points[1] = curve->G;
+ points[2] = _public;
+ points[3] = sum;
+ num_bits = smax(uECC_vli_numBits(u1, num_n_words),
+ uECC_vli_numBits(u2, num_n_words));
+
+ point = points[(!!uECC_vli_testBit(u1, num_bits - 1)) |
+ ((!!uECC_vli_testBit(u2, num_bits - 1)) << 1)];
+ uECC_vli_set(rx, point, num_words);
+ uECC_vli_set(ry, point + num_words, num_words);
+ uECC_vli_clear(z, num_words);
+ z[0] = 1;
+
+ for (i = num_bits - 2; i >= 0; --i) {
+ uECC_word_t index;
+ curve->double_jacobian(rx, ry, z, curve);
+
+ index = (!!uECC_vli_testBit(u1, i)) | ((!!uECC_vli_testBit(u2, i)) << 1);
+ point = points[index];
+ if (point) {
+ uECC_vli_set(tx, point, num_words);
+ uECC_vli_set(ty, point + num_words, num_words);
+ apply_z(tx, ty, z, curve);
+ uECC_vli_modSub(tz, rx, tx, curve->p, num_words); /* Z = x2 - x1 */
+ XYcZ_add(tx, ty, rx, ry, curve);
+ uECC_vli_modMult_fast(z, z, tz, curve);
+ }
+ }
+
+ uECC_vli_modInv(z, z, curve->p, num_words); /* Z = 1/Z */
+ apply_z(rx, ry, z, curve);
+
+ /* v = x1 (mod n) */
+ if (uECC_vli_cmp_unsafe(curve->n, rx, num_n_words) != 1) {
+ uECC_vli_sub(rx, rx, curve->n, num_n_words);
}
- return (vli_cmp(p_point.x, r, NUM_ECC_DIGITS) == 0);
+ /* Accept only if v == r. */
+ return (int)(uECC_vli_equal(rx, r, num_words) == 0);
}
+