ext: Pull in tinycrypt v0.2.6
Zephyr 1.9 moves to tinycrypt v0.2.7. This introduces a breaking API
change. This makes things challenging for mcuboot, which would like to
be able to work across multiple platforms.
To help with this, bring in the last working version of Tinycrypt v0.2.6
from https://github.com/01org/tinycrypt. Tinycrypt is released under a
3-clause BSD-style license, with parts under the micro-ecc license,
which is a 2-clause license. Please see ext/tinycrypt/LICENSE for
details.
Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/ext/tinycrypt/lib/source/ecc_dsa.c b/ext/tinycrypt/lib/source/ecc_dsa.c
new file mode 100644
index 0000000..dd84a18
--- /dev/null
+++ b/ext/tinycrypt/lib/source/ecc_dsa.c
@@ -0,0 +1,115 @@
+/* ec_dsa.c - TinyCrypt implementation of EC-DSA */
+
+/*
+ * Copyright (C) 2015 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:
+ *
+ * - 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.
+ *
+ * - Neither the name of Intel Corporation nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * 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 OWNER 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.
+ */
+
+#include <tinycrypt/constants.h>
+#include <tinycrypt/ecc.h>
+
+extern uint32_t curve_n[NUM_ECC_DIGITS];
+extern EccPoint curve_G;
+extern uint32_t curve_nb[NUM_ECC_DIGITS + 1];
+
+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])
+{
+
+ 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. */
+ }
+
+ 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);
+ }
+
+ if (vli_isZero(r)) {
+ return TC_CRYPTO_FAIL; /* If r == 0, fail (need a different random number). */
+ }
+
+ 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])
+{
+
+ uint32_t u1[NUM_ECC_DIGITS], u2[NUM_ECC_DIGITS];
+ uint32_t z[NUM_ECC_DIGITS];
+ EccPointJacobi P, R;
+ EccPoint p_point;
+
+ if (vli_isZero(r) || vli_isZero(s)) {
+ return TC_CRYPTO_FAIL; /* r, s must not be 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. */
+ }
+
+ /* 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 */
+
+ /* 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);
+
+ /* Accept only if P.x == r. */
+ if (!vli_sub(z, p_point.x, curve_n, NUM_ECC_DIGITS)) {
+ vli_set(p_point.x, z);
+ }
+
+ return (vli_cmp(p_point.x, r, NUM_ECC_DIGITS) == 0);
+}