From: Salvatore Benedetto Subject: [PATCH v9 3/3] crypto: kpp - Add ECDH software support Date: Fri, 17 Jun 2016 15:37:45 +0100 Message-ID: <1466174265-4546-4-git-send-email-salvatore.benedetto@intel.com> References: <1466174265-4546-1-git-send-email-salvatore.benedetto@intel.com> Cc: salvatore.benedetto@intel.com, linux-crypto@vger.kernel.org To: herbert@gondor.apana.org.au Return-path: Received: from mga02.intel.com ([134.134.136.20]:47115 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750751AbcFQOiS (ORCPT ); Fri, 17 Jun 2016 10:38:18 -0400 In-Reply-To: <1466174265-4546-1-git-send-email-salvatore.benedetto@intel.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: * Implement ECDH under kpp API * Provide ECC software support for curve P-192 and P-256. * Add kpp test for ECDH with data generated by OpenSSL Signed-off-by: Salvatore Benedetto --- crypto/Kconfig | 5 + crypto/Makefile | 4 + crypto/ecc.c | 1018 +++++++++++++++++++++++++++++++++++++++++++++++ crypto/ecc.h | 83 ++++ crypto/ecc_curve_defs.h | 57 +++ crypto/ecdh.c | 151 +++++++ crypto/ecdh_helper.c | 75 ++++ crypto/testmgr.c | 176 +++++++- crypto/testmgr.h | 78 ++++ include/crypto/ecdh.h | 30 ++ include/crypto/kpp.h | 1 + 11 files changed, 1669 insertions(+), 9 deletions(-) create mode 100644 crypto/ecc.c create mode 100644 crypto/ecc.h create mode 100644 crypto/ecc_curve_defs.h create mode 100644 crypto/ecdh.c create mode 100644 crypto/ecdh_helper.c create mode 100644 include/crypto/ecdh.h diff --git a/crypto/Kconfig b/crypto/Kconfig index 92b5f0b..d0492ae 100644 --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -118,6 +118,11 @@ config CRYPTO_DH help Generic implementation of the Diffie-Hellman algorithm. +config CRYPTO_ECDH + tristate "ECDH algorithm" + select CRYTPO_KPP + help + Generic implementation of the ECDH algorithm config CRYPTO_MANAGER tristate "Cryptographic algorithm manager" diff --git a/crypto/Makefile b/crypto/Makefile index 28e8708..47b1fae 100644 --- a/crypto/Makefile +++ b/crypto/Makefile @@ -35,6 +35,10 @@ obj-$(CONFIG_CRYPTO_KPP2) += kpp.o dh_generic-y := dh.o dh_generic-y += dh_helper.o obj-$(CONFIG_CRYPTO_DH) += dh_generic.o +ecdh_generic-y := ecc.o +ecdh_generic-y += ecdh.o +ecdh_generic-y += ecdh_helper.o +obj-$(CONFIG_CRYPTO_ECDH) += ecdh_generic.o $(obj)/rsapubkey-asn1.o: $(obj)/rsapubkey-asn1.c $(obj)/rsapubkey-asn1.h $(obj)/rsaprivkey-asn1.o: $(obj)/rsaprivkey-asn1.c $(obj)/rsaprivkey-asn1.h diff --git a/crypto/ecc.c b/crypto/ecc.c new file mode 100644 index 0000000..9aedec6 --- /dev/null +++ b/crypto/ecc.c @@ -0,0 +1,1018 @@ +/* + * Copyright (c) 2013, 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. + */ + +#include +#include +#include +#include +#include + +#include "ecc.h" +#include "ecc_curve_defs.h" + +typedef struct { + u64 m_low; + u64 m_high; +} uint128_t; + +static inline const struct ecc_curve *ecc_get_curve(unsigned int curve_id) +{ + switch (curve_id) { + /* In FIPS mode only allow P256 and higher */ + case ECC_CURVE_NIST_P192: + return fips_enabled ? NULL : &nist_p192; + case ECC_CURVE_NIST_P256: + return &nist_p256; + default: + return NULL; + } +} + +static u64 *ecc_alloc_digits_space(unsigned int ndigits) +{ + size_t len = ndigits * sizeof(u64); + + if (!len) + return NULL; + + return kmalloc(len, GFP_KERNEL); +} + +static void ecc_free_digits_space(u64 *space) +{ + kzfree(space); +} + +static struct ecc_point *ecc_alloc_point(unsigned int ndigits) +{ + struct ecc_point *p = kmalloc(sizeof(*p), GFP_KERNEL); + + if (!p) + return NULL; + + p->x = ecc_alloc_digits_space(ndigits); + if (!p->x) + goto err_alloc_x; + + p->y = ecc_alloc_digits_space(ndigits); + if (!p->y) + goto err_alloc_y; + + p->ndigits = ndigits; + + return p; + +err_alloc_y: + ecc_free_digits_space(p->x); +err_alloc_x: + kfree(p); + return NULL; +} + +static void ecc_free_point(struct ecc_point *p) +{ + if (!p) + return; + + kzfree(p->x); + kzfree(p->y); + kzfree(p); +} + +static void vli_clear(u64 *vli, unsigned int ndigits) +{ + int i; + + for (i = 0; i < ndigits; i++) + vli[i] = 0; +} + +/* Returns true if vli == 0, false otherwise. */ +static bool vli_is_zero(const u64 *vli, unsigned int ndigits) +{ + int i; + + for (i = 0; i < ndigits; i++) { + if (vli[i]) + return false; + } + + return true; +} + +/* Returns nonzero if bit bit of vli is set. */ +static u64 vli_test_bit(const u64 *vli, unsigned int bit) +{ + return (vli[bit / 64] & ((u64)1 << (bit % 64))); +} + +/* Counts the number of 64-bit "digits" in vli. */ +static unsigned int vli_num_digits(const u64 *vli, unsigned int ndigits) +{ + int i; + + /* Search from the end until we find a non-zero digit. + * We do it in reverse because we expect that most digits will + * be nonzero. + */ + for (i = ndigits - 1; i >= 0 && vli[i] == 0; i--); + + return (i + 1); +} + +/* Counts the number of bits required for vli. */ +static unsigned int vli_num_bits(const u64 *vli, unsigned int ndigits) +{ + unsigned int i, num_digits; + u64 digit; + + num_digits = vli_num_digits(vli, ndigits); + if (num_digits == 0) + return 0; + + digit = vli[num_digits - 1]; + for (i = 0; digit; i++) + digit >>= 1; + + return ((num_digits - 1) * 64 + i); +} + +/* Sets dest = src. */ +static void vli_set(u64 *dest, const u64 *src, unsigned int ndigits) +{ + int i; + + for (i = 0; i < ndigits; i++) + dest[i] = src[i]; +} + +/* Returns sign of left - right. */ +static int vli_cmp(const u64 *left, const u64 *right, unsigned int ndigits) +{ + int i; + + for (i = ndigits - 1; i >= 0; i--) { + if (left[i] > right[i]) + return 1; + else if (left[i] < right[i]) + return -1; + } + + return 0; +} + +/* Computes result = in << c, returning carry. Can modify in place + * (if result == in). 0 < shift < 64. + */ +static u64 vli_lshift(u64 *result, const u64 *in, unsigned int shift, + unsigned int ndigits) +{ + u64 carry = 0; + int i; + + for (i = 0; i < ndigits; i++) { + u64 temp = in[i]; + + result[i] = (temp << shift) | carry; + carry = temp >> (64 - shift); + } + + return carry; +} + +/* Computes vli = vli >> 1. */ +static void vli_rshift1(u64 *vli, unsigned int ndigits) +{ + u64 *end = vli; + u64 carry = 0; + + vli += ndigits; + + while (vli-- > end) { + u64 temp = *vli; + *vli = (temp >> 1) | carry; + carry = temp << 63; + } +} + +/* Computes result = left + right, returning carry. Can modify in place. */ +static u64 vli_add(u64 *result, const u64 *left, const u64 *right, + unsigned int ndigits) +{ + u64 carry = 0; + int i; + + for (i = 0; i < ndigits; i++) { + u64 sum; + + sum = left[i] + right[i] + carry; + if (sum != left[i]) + carry = (sum < left[i]); + + result[i] = sum; + } + + return carry; +} + +/* Computes result = left - right, returning borrow. Can modify in place. */ +static u64 vli_sub(u64 *result, const u64 *left, const u64 *right, + unsigned int ndigits) +{ + u64 borrow = 0; + int i; + + for (i = 0; i < ndigits; i++) { + u64 diff; + + diff = left[i] - right[i] - borrow; + if (diff != left[i]) + borrow = (diff > left[i]); + + result[i] = diff; + } + + return borrow; +} + +static uint128_t mul_64_64(u64 left, u64 right) +{ + u64 a0 = left & 0xffffffffull; + u64 a1 = left >> 32; + u64 b0 = right & 0xffffffffull; + u64 b1 = right >> 32; + u64 m0 = a0 * b0; + u64 m1 = a0 * b1; + u64 m2 = a1 * b0; + u64 m3 = a1 * b1; + uint128_t result; + + m2 += (m0 >> 32); + m2 += m1; + + /* Overflow */ + if (m2 < m1) + m3 += 0x100000000ull; + + result.m_low = (m0 & 0xffffffffull) | (m2 << 32); + result.m_high = m3 + (m2 >> 32); + + return result; +} + +static uint128_t add_128_128(uint128_t a, uint128_t b) +{ + uint128_t result; + + result.m_low = a.m_low + b.m_low; + result.m_high = a.m_high + b.m_high + (result.m_low < a.m_low); + + return result; +} + +static void vli_mult(u64 *result, const u64 *left, const u64 *right, + unsigned int ndigits) +{ + uint128_t r01 = { 0, 0 }; + u64 r2 = 0; + unsigned int i, k; + + /* Compute each digit of result in sequence, maintaining the + * carries. + */ + for (k = 0; k < ndigits * 2 - 1; k++) { + unsigned int min; + + if (k < ndigits) + min = 0; + else + min = (k + 1) - ndigits; + + for (i = min; i <= k && i < ndigits; i++) { + uint128_t product; + + product = mul_64_64(left[i], right[k - i]); + + r01 = add_128_128(r01, product); + r2 += (r01.m_high < product.m_high); + } + + result[k] = r01.m_low; + r01.m_low = r01.m_high; + r01.m_high = r2; + r2 = 0; + } + + result[ndigits * 2 - 1] = r01.m_low; +} + +static void vli_square(u64 *result, const u64 *left, unsigned int ndigits) +{ + uint128_t r01 = { 0, 0 }; + u64 r2 = 0; + int i, k; + + for (k = 0; k < ndigits * 2 - 1; k++) { + unsigned int min; + + if (k < ndigits) + min = 0; + else + min = (k + 1) - ndigits; + + for (i = min; i <= k && i <= k - i; i++) { + uint128_t product; + + product = mul_64_64(left[i], left[k - i]); + + if (i < k - i) { + r2 += product.m_high >> 63; + product.m_high = (product.m_high << 1) | + (product.m_low >> 63); + product.m_low <<= 1; + } + + r01 = add_128_128(r01, product); + r2 += (r01.m_high < product.m_high); + } + + result[k] = r01.m_low; + r01.m_low = r01.m_high; + r01.m_high = r2; + r2 = 0; + } + + result[ndigits * 2 - 1] = r01.m_low; +} + +/* Computes result = (left + right) % mod. + * Assumes that left < mod and right < mod, result != mod. + */ +static void vli_mod_add(u64 *result, const u64 *left, const u64 *right, + const u64 *mod, unsigned int ndigits) +{ + u64 carry; + + carry = vli_add(result, left, right, ndigits); + + /* result > mod (result = mod + remainder), so subtract mod to + * get remainder. + */ + if (carry || vli_cmp(result, mod, ndigits) >= 0) + vli_sub(result, result, mod, ndigits); +} + +/* Computes result = (left - right) % mod. + * Assumes that left < mod and right < mod, result != mod. + */ +static void vli_mod_sub(u64 *result, const u64 *left, const u64 *right, + const u64 *mod, unsigned int ndigits) +{ + u64 borrow = vli_sub(result, left, right, ndigits); + + /* In this case, p_result == -diff == (max int) - diff. + * Since -x % d == d - x, we can get the correct result from + * result + mod (with overflow). + */ + if (borrow) + vli_add(result, result, mod, ndigits); +} + +/* Computes p_result = p_product % curve_p. + * See algorithm 5 and 6 from + * http://www.isys.uni-klu.ac.at/PDF/2001-0126-MT.pdf + */ +static void vli_mmod_fast_192(u64 *result, const u64 *product, + const u64 *curve_prime, u64 *tmp) +{ + const unsigned int ndigits = 3; + int carry; + + vli_set(result, product, ndigits); + + vli_set(tmp, &product[3], ndigits); + carry = vli_add(result, result, tmp, ndigits); + + tmp[0] = 0; + tmp[1] = product[3]; + tmp[2] = product[4]; + carry += vli_add(result, result, tmp, ndigits); + + tmp[0] = tmp[1] = product[5]; + tmp[2] = 0; + carry += vli_add(result, result, tmp, ndigits); + + while (carry || vli_cmp(curve_prime, result, ndigits) != 1) + carry -= vli_sub(result, result, curve_prime, ndigits); +} + +/* Computes result = product % curve_prime + * from http://www.nsa.gov/ia/_files/nist-routines.pdf + */ +static void vli_mmod_fast_256(u64 *result, const u64 *product, + const u64 *curve_prime, u64 *tmp) +{ + int carry; + const unsigned int ndigits = 4; + + /* t */ + vli_set(result, product, ndigits); + + /* s1 */ + tmp[0] = 0; + tmp[1] = product[5] & 0xffffffff00000000ull; + tmp[2] = product[6]; + tmp[3] = product[7]; + carry = vli_lshift(tmp, tmp, 1, ndigits); + carry += vli_add(result, result, tmp, ndigits); + + /* s2 */ + tmp[1] = product[6] << 32; + tmp[2] = (product[6] >> 32) | (product[7] << 32); + tmp[3] = product[7] >> 32; + carry += vli_lshift(tmp, tmp, 1, ndigits); + carry += vli_add(result, result, tmp, ndigits); + + /* s3 */ + tmp[0] = product[4]; + tmp[1] = product[5] & 0xffffffff; + tmp[2] = 0; + tmp[3] = product[7]; + carry += vli_add(result, result, tmp, ndigits); + + /* s4 */ + tmp[0] = (product[4] >> 32) | (product[5] << 32); + tmp[1] = (product[5] >> 32) | (product[6] & 0xffffffff00000000ull); + tmp[2] = product[7]; + tmp[3] = (product[6] >> 32) | (product[4] << 32); + carry += vli_add(result, result, tmp, ndigits); + + /* d1 */ + tmp[0] = (product[5] >> 32) | (product[6] << 32); + tmp[1] = (product[6] >> 32); + tmp[2] = 0; + tmp[3] = (product[4] & 0xffffffff) | (product[5] << 32); + carry -= vli_sub(result, result, tmp, ndigits); + + /* d2 */ + tmp[0] = product[6]; + tmp[1] = product[7]; + tmp[2] = 0; + tmp[3] = (product[4] >> 32) | (product[5] & 0xffffffff00000000ull); + carry -= vli_sub(result, result, tmp, ndigits); + + /* d3 */ + tmp[0] = (product[6] >> 32) | (product[7] << 32); + tmp[1] = (product[7] >> 32) | (product[4] << 32); + tmp[2] = (product[4] >> 32) | (product[5] << 32); + tmp[3] = (product[6] << 32); + carry -= vli_sub(result, result, tmp, ndigits); + + /* d4 */ + tmp[0] = product[7]; + tmp[1] = product[4] & 0xffffffff00000000ull; + tmp[2] = product[5]; + tmp[3] = product[6] & 0xffffffff00000000ull; + carry -= vli_sub(result, result, tmp, ndigits); + + if (carry < 0) { + do { + carry += vli_add(result, result, curve_prime, ndigits); + } while (carry < 0); + } else { + while (carry || vli_cmp(curve_prime, result, ndigits) != 1) + carry -= vli_sub(result, result, curve_prime, ndigits); + } +} + +/* Computes result = product % curve_prime + * from http://www.nsa.gov/ia/_files/nist-routines.pdf +*/ +static bool vli_mmod_fast(u64 *result, u64 *product, + const u64 *curve_prime, unsigned int ndigits) +{ + u64 tmp[2 * ndigits]; + + switch (ndigits) { + case 3: + vli_mmod_fast_192(result, product, curve_prime, tmp); + break; + case 4: + vli_mmod_fast_256(result, product, curve_prime, tmp); + break; + default: + pr_err("unsupports digits size!\n"); + return false; + } + + return true; +} + +/* Computes result = (left * right) % curve_prime. */ +static void vli_mod_mult_fast(u64 *result, const u64 *left, const u64 *right, + const u64 *curve_prime, unsigned int ndigits) +{ + u64 product[2 * ndigits]; + + vli_mult(product, left, right, ndigits); + vli_mmod_fast(result, product, curve_prime, ndigits); +} + +/* Computes result = left^2 % curve_prime. */ +static void vli_mod_square_fast(u64 *result, const u64 *left, + const u64 *curve_prime, unsigned int ndigits) +{ + u64 product[2 * ndigits]; + + vli_square(product, left, ndigits); + vli_mmod_fast(result, product, curve_prime, ndigits); +} + +#define EVEN(vli) (!(vli[0] & 1)) +/* Computes result = (1 / p_input) % mod. All VLIs are the same size. + * See "From Euclid's GCD to Montgomery Multiplication to the Great Divide" + * https://labs.oracle.com/techrep/2001/smli_tr-2001-95.pdf + */ +static void vli_mod_inv(u64 *result, const u64 *input, const u64 *mod, + unsigned int ndigits) +{ + u64 a[ndigits], b[ndigits]; + u64 u[ndigits], v[ndigits]; + u64 carry; + int cmp_result; + + if (vli_is_zero(input, ndigits)) { + vli_clear(result, ndigits); + return; + } + + vli_set(a, input, ndigits); + vli_set(b, mod, ndigits); + vli_clear(u, ndigits); + u[0] = 1; + vli_clear(v, ndigits); + + while ((cmp_result = vli_cmp(a, b, ndigits)) != 0) { + carry = 0; + + if (EVEN(a)) { + vli_rshift1(a, ndigits); + + if (!EVEN(u)) + carry = vli_add(u, u, mod, ndigits); + + vli_rshift1(u, ndigits); + if (carry) + u[ndigits - 1] |= 0x8000000000000000ull; + } else if (EVEN(b)) { + vli_rshift1(b, ndigits); + + if (!EVEN(v)) + carry = vli_add(v, v, mod, ndigits); + + vli_rshift1(v, ndigits); + if (carry) + v[ndigits - 1] |= 0x8000000000000000ull; + } else if (cmp_result > 0) { + vli_sub(a, a, b, ndigits); + vli_rshift1(a, ndigits); + + if (vli_cmp(u, v, ndigits) < 0) + vli_add(u, u, mod, ndigits); + + vli_sub(u, u, v, ndigits); + if (!EVEN(u)) + carry = vli_add(u, u, mod, ndigits); + + vli_rshift1(u, ndigits); + if (carry) + u[ndigits - 1] |= 0x8000000000000000ull; + } else { + vli_sub(b, b, a, ndigits); + vli_rshift1(b, ndigits); + + if (vli_cmp(v, u, ndigits) < 0) + vli_add(v, v, mod, ndigits); + + vli_sub(v, v, u, ndigits); + if (!EVEN(v)) + carry = vli_add(v, v, mod, ndigits); + + vli_rshift1(v, ndigits); + if (carry) + v[ndigits - 1] |= 0x8000000000000000ull; + } + } + + vli_set(result, u, ndigits); +} + +/* ------ Point operations ------ */ + +/* Returns true if p_point is the point at infinity, false otherwise. */ +static bool ecc_point_is_zero(const struct ecc_point *point) +{ + return (vli_is_zero(point->x, point->ndigits) && + vli_is_zero(point->y, point->ndigits)); +} + +/* Point multiplication algorithm using Montgomery's ladder with co-Z + * coordinates. From http://eprint.iacr.org/2011/338.pdf + */ + +/* Double in place */ +static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1, + u64 *curve_prime, unsigned int ndigits) +{ + /* t1 = x, t2 = y, t3 = z */ + u64 t4[ndigits]; + u64 t5[ndigits]; + + if (vli_is_zero(z1, ndigits)) + return; + + /* t4 = y1^2 */ + vli_mod_square_fast(t4, y1, curve_prime, ndigits); + /* t5 = x1*y1^2 = A */ + vli_mod_mult_fast(t5, x1, t4, curve_prime, ndigits); + /* t4 = y1^4 */ + vli_mod_square_fast(t4, t4, curve_prime, ndigits); + /* t2 = y1*z1 = z3 */ + vli_mod_mult_fast(y1, y1, z1, curve_prime, ndigits); + /* t3 = z1^2 */ + vli_mod_square_fast(z1, z1, curve_prime, ndigits); + + /* t1 = x1 + z1^2 */ + vli_mod_add(x1, x1, z1, curve_prime, ndigits); + /* t3 = 2*z1^2 */ + vli_mod_add(z1, z1, z1, curve_prime, ndigits); + /* t3 = x1 - z1^2 */ + vli_mod_sub(z1, x1, z1, curve_prime, ndigits); + /* t1 = x1^2 - z1^4 */ + vli_mod_mult_fast(x1, x1, z1, curve_prime, ndigits); + + /* t3 = 2*(x1^2 - z1^4) */ + vli_mod_add(z1, x1, x1, curve_prime, ndigits); + /* t1 = 3*(x1^2 - z1^4) */ + vli_mod_add(x1, x1, z1, curve_prime, ndigits); + if (vli_test_bit(x1, 0)) { + u64 carry = vli_add(x1, x1, curve_prime, ndigits); + + vli_rshift1(x1, ndigits); + x1[ndigits - 1] |= carry << 63; + } else { + vli_rshift1(x1, ndigits); + } + /* t1 = 3/2*(x1^2 - z1^4) = B */ + + /* t3 = B^2 */ + vli_mod_square_fast(z1, x1, curve_prime, ndigits); + /* t3 = B^2 - A */ + vli_mod_sub(z1, z1, t5, curve_prime, ndigits); + /* t3 = B^2 - 2A = x3 */ + vli_mod_sub(z1, z1, t5, curve_prime, ndigits); + /* t5 = A - x3 */ + vli_mod_sub(t5, t5, z1, curve_prime, ndigits); + /* t1 = B * (A - x3) */ + vli_mod_mult_fast(x1, x1, t5, curve_prime, ndigits); + /* t4 = B * (A - x3) - y1^4 = y3 */ + vli_mod_sub(t4, x1, t4, curve_prime, ndigits); + + vli_set(x1, z1, ndigits); + vli_set(z1, y1, ndigits); + vli_set(y1, t4, ndigits); +} + +/* Modify (x1, y1) => (x1 * z^2, y1 * z^3) */ +static void apply_z(u64 *x1, u64 *y1, u64 *z, u64 *curve_prime, + unsigned int ndigits) +{ + u64 t1[ndigits]; + + vli_mod_square_fast(t1, z, curve_prime, ndigits); /* z^2 */ + vli_mod_mult_fast(x1, x1, t1, curve_prime, ndigits); /* x1 * z^2 */ + vli_mod_mult_fast(t1, t1, z, curve_prime, ndigits); /* z^3 */ + vli_mod_mult_fast(y1, y1, t1, curve_prime, ndigits); /* y1 * z^3 */ +} + +/* P = (x1, y1) => 2P, (x2, y2) => P' */ +static void xycz_initial_double(u64 *x1, u64 *y1, u64 *x2, u64 *y2, + u64 *p_initial_z, u64 *curve_prime, + unsigned int ndigits) +{ + u64 z[ndigits]; + + vli_set(x2, x1, ndigits); + vli_set(y2, y1, ndigits); + + vli_clear(z, ndigits); + z[0] = 1; + + if (p_initial_z) + vli_set(z, p_initial_z, ndigits); + + apply_z(x1, y1, z, curve_prime, ndigits); + + ecc_point_double_jacobian(x1, y1, z, curve_prime, ndigits); + + apply_z(x2, y2, z, curve_prime, ndigits); +} + +/* Input P = (x1, y1, Z), Q = (x2, y2, Z) + * Output P' = (x1', y1', Z3), P + Q = (x3, y3, Z3) + * or P => P', Q => P + Q + */ +static void xycz_add(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime, + unsigned int ndigits) +{ + /* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */ + u64 t5[ndigits]; + + /* t5 = x2 - x1 */ + vli_mod_sub(t5, x2, x1, curve_prime, ndigits); + /* t5 = (x2 - x1)^2 = A */ + vli_mod_square_fast(t5, t5, curve_prime, ndigits); + /* t1 = x1*A = B */ + vli_mod_mult_fast(x1, x1, t5, curve_prime, ndigits); + /* t3 = x2*A = C */ + vli_mod_mult_fast(x2, x2, t5, curve_prime, ndigits); + /* t4 = y2 - y1 */ + vli_mod_sub(y2, y2, y1, curve_prime, ndigits); + /* t5 = (y2 - y1)^2 = D */ + vli_mod_square_fast(t5, y2, curve_prime, ndigits); + + /* t5 = D - B */ + vli_mod_sub(t5, t5, x1, curve_prime, ndigits); + /* t5 = D - B - C = x3 */ + vli_mod_sub(t5, t5, x2, curve_prime, ndigits); + /* t3 = C - B */ + vli_mod_sub(x2, x2, x1, curve_prime, ndigits); + /* t2 = y1*(C - B) */ + vli_mod_mult_fast(y1, y1, x2, curve_prime, ndigits); + /* t3 = B - x3 */ + vli_mod_sub(x2, x1, t5, curve_prime, ndigits); + /* t4 = (y2 - y1)*(B - x3) */ + vli_mod_mult_fast(y2, y2, x2, curve_prime, ndigits); + /* t4 = y3 */ + vli_mod_sub(y2, y2, y1, curve_prime, ndigits); + + vli_set(x2, t5, ndigits); +} + +/* Input P = (x1, y1, Z), Q = (x2, y2, Z) + * Output P + Q = (x3, y3, Z3), P - Q = (x3', y3', Z3) + * or P => P - Q, Q => P + Q + */ +static void xycz_add_c(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime, + unsigned int ndigits) +{ + /* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */ + u64 t5[ndigits]; + u64 t6[ndigits]; + u64 t7[ndigits]; + + /* t5 = x2 - x1 */ + vli_mod_sub(t5, x2, x1, curve_prime, ndigits); + /* t5 = (x2 - x1)^2 = A */ + vli_mod_square_fast(t5, t5, curve_prime, ndigits); + /* t1 = x1*A = B */ + vli_mod_mult_fast(x1, x1, t5, curve_prime, ndigits); + /* t3 = x2*A = C */ + vli_mod_mult_fast(x2, x2, t5, curve_prime, ndigits); + /* t4 = y2 + y1 */ + vli_mod_add(t5, y2, y1, curve_prime, ndigits); + /* t4 = y2 - y1 */ + vli_mod_sub(y2, y2, y1, curve_prime, ndigits); + + /* t6 = C - B */ + vli_mod_sub(t6, x2, x1, curve_prime, ndigits); + /* t2 = y1 * (C - B) */ + vli_mod_mult_fast(y1, y1, t6, curve_prime, ndigits); + /* t6 = B + C */ + vli_mod_add(t6, x1, x2, curve_prime, ndigits); + /* t3 = (y2 - y1)^2 */ + vli_mod_square_fast(x2, y2, curve_prime, ndigits); + /* t3 = x3 */ + vli_mod_sub(x2, x2, t6, curve_prime, ndigits); + + /* t7 = B - x3 */ + vli_mod_sub(t7, x1, x2, curve_prime, ndigits); + /* t4 = (y2 - y1)*(B - x3) */ + vli_mod_mult_fast(y2, y2, t7, curve_prime, ndigits); + /* t4 = y3 */ + vli_mod_sub(y2, y2, y1, curve_prime, ndigits); + + /* t7 = (y2 + y1)^2 = F */ + vli_mod_square_fast(t7, t5, curve_prime, ndigits); + /* t7 = x3' */ + vli_mod_sub(t7, t7, t6, curve_prime, ndigits); + /* t6 = x3' - B */ + vli_mod_sub(t6, t7, x1, curve_prime, ndigits); + /* t6 = (y2 + y1)*(x3' - B) */ + vli_mod_mult_fast(t6, t6, t5, curve_prime, ndigits); + /* t2 = y3' */ + vli_mod_sub(y1, t6, y1, curve_prime, ndigits); + + vli_set(x1, t7, ndigits); +} + +static void ecc_point_mult(struct ecc_point *result, + const struct ecc_point *point, const u64 *scalar, + u64 *initial_z, u64 *curve_prime, + unsigned int ndigits) +{ + /* R0 and R1 */ + u64 rx[2][ndigits]; + u64 ry[2][ndigits]; + u64 z[ndigits]; + int i, nb; + int num_bits = vli_num_bits(scalar, ndigits); + + vli_set(rx[1], point->x, ndigits); + vli_set(ry[1], point->y, ndigits); + + xycz_initial_double(rx[1], ry[1], rx[0], ry[0], initial_z, curve_prime, + ndigits); + + for (i = num_bits - 2; i > 0; i--) { + nb = !vli_test_bit(scalar, i); + xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb], curve_prime, + ndigits); + xycz_add(rx[nb], ry[nb], rx[1 - nb], ry[1 - nb], curve_prime, + ndigits); + } + + nb = !vli_test_bit(scalar, 0); + xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb], curve_prime, + ndigits); + + /* Find final 1/Z value. */ + /* X1 - X0 */ + vli_mod_sub(z, rx[1], rx[0], curve_prime, ndigits); + /* Yb * (X1 - X0) */ + vli_mod_mult_fast(z, z, ry[1 - nb], curve_prime, ndigits); + /* xP * Yb * (X1 - X0) */ + vli_mod_mult_fast(z, z, point->x, curve_prime, ndigits); + + /* 1 / (xP * Yb * (X1 - X0)) */ + vli_mod_inv(z, z, curve_prime, point->ndigits); + + /* yP / (xP * Yb * (X1 - X0)) */ + vli_mod_mult_fast(z, z, point->y, curve_prime, ndigits); + /* Xb * yP / (xP * Yb * (X1 - X0)) */ + vli_mod_mult_fast(z, z, rx[1 - nb], curve_prime, ndigits); + /* End 1/Z calculation */ + + xycz_add(rx[nb], ry[nb], rx[1 - nb], ry[1 - nb], curve_prime, ndigits); + + apply_z(rx[0], ry[0], z, curve_prime, ndigits); + + vli_set(result->x, rx[0], ndigits); + vli_set(result->y, ry[0], ndigits); +} + +static inline void ecc_swap_digits(const u64 *in, u64 *out, + unsigned int ndigits) +{ + int i; + + for (i = 0; i < ndigits; i++) + out[i] = __swab64(in[ndigits - 1 - i]); +} + +int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits, + const u8 *private_key, unsigned int private_key_len) +{ + int nbytes; + const struct ecc_curve *curve = ecc_get_curve(curve_id); + + if (!private_key) + return -EINVAL; + + nbytes = ndigits << ECC_DIGITS_TO_BYTES_SHIFT; + + if (private_key_len != nbytes) + return -EINVAL; + + if (vli_is_zero((const u64 *)&private_key[0], ndigits)) + return -EINVAL; + + /* Make sure the private key is in the range [1, n-1]. */ + if (vli_cmp(curve->n, (const u64 *)&private_key[0], ndigits) != 1) + return -EINVAL; + + return 0; +} + +int ecdh_make_pub_key(unsigned int curve_id, unsigned int ndigits, + const u8 *private_key, unsigned int private_key_len, + u8 *public_key, unsigned int public_key_len) +{ + int ret = 0; + struct ecc_point *pk; + u64 priv[ndigits]; + unsigned int nbytes; + const struct ecc_curve *curve = ecc_get_curve(curve_id); + + if (!private_key || !curve) { + ret = -EINVAL; + goto out; + } + + ecc_swap_digits((const u64 *)private_key, priv, ndigits); + + pk = ecc_alloc_point(ndigits); + if (!pk) { + ret = -ENOMEM; + goto out; + } + + ecc_point_mult(pk, &curve->g, priv, NULL, curve->p, ndigits); + if (ecc_point_is_zero(pk)) { + ret = -EAGAIN; + goto err_free_point; + } + + nbytes = ndigits << ECC_DIGITS_TO_BYTES_SHIFT; + ecc_swap_digits(pk->x, (u64 *)public_key, ndigits); + ecc_swap_digits(pk->y, (u64 *)&public_key[nbytes], ndigits); + +err_free_point: + ecc_free_point(pk); +out: + return ret; +} + +int ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits, + const u8 *private_key, unsigned int private_key_len, + const u8 *public_key, unsigned int public_key_len, + u8 *secret, unsigned int secret_len) +{ + int ret = 0; + struct ecc_point *product, *pk; + u64 priv[ndigits]; + u64 rand_z[ndigits]; + unsigned int nbytes; + const struct ecc_curve *curve = ecc_get_curve(curve_id); + + if (!private_key || !public_key || !curve) { + ret = -EINVAL; + goto out; + } + + nbytes = ndigits << ECC_DIGITS_TO_BYTES_SHIFT; + + get_random_bytes(rand_z, nbytes); + + pk = ecc_alloc_point(ndigits); + if (!pk) { + ret = -ENOMEM; + goto out; + } + + product = ecc_alloc_point(ndigits); + if (!product) { + ret = -ENOMEM; + goto err_alloc_product; + } + + ecc_swap_digits((const u64 *)public_key, pk->x, ndigits); + ecc_swap_digits((const u64 *)&public_key[nbytes], pk->y, ndigits); + ecc_swap_digits((const u64 *)private_key, priv, ndigits); + + ecc_point_mult(product, pk, priv, rand_z, curve->p, ndigits); + + ecc_swap_digits(product->x, (u64 *)secret, ndigits); + + if (ecc_point_is_zero(product)) + ret = -EFAULT; + + ecc_free_point(product); +err_alloc_product: + ecc_free_point(pk); +out: + return ret; +} diff --git a/crypto/ecc.h b/crypto/ecc.h new file mode 100644 index 0000000..b5db4b9 --- /dev/null +++ b/crypto/ecc.h @@ -0,0 +1,83 @@ +/* + * Copyright (c) 2013, 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. + */ +#ifndef _CRYPTO_ECC_H +#define _CRYPTO_ECC_H + +#define ECC_MAX_DIGITS 4 /* 256 */ + +#define ECC_DIGITS_TO_BYTES_SHIFT 3 + +/** + * ecc_is_key_valid() - Validate a given ECDH private key + * + * @curve_id: id representing the curve to use + * @ndigits: curve number of digits + * @private_key: private key to be used for the given curve + * @private_key_len: private key len + * + * Returns 0 if the key is acceptable, a negative value otherwise + */ +int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits, + const u8 *private_key, unsigned int private_key_len); + +/** + * ecdh_make_pub_key() - Compute an ECC public key + * + * @curve_id: id representing the curve to use + * @private_key: pregenerated private key for the given curve + * @private_key_len: length of private_key + * @public_key: buffer for storing the public key generated + * @public_key_len: length of the public_key buffer + * + * Returns 0 if the public key was generated successfully, a negative value + * if an error occurred. + */ +int ecdh_make_pub_key(const unsigned int curve_id, unsigned int ndigits, + const u8 *private_key, unsigned int private_key_len, + u8 *public_key, unsigned int public_key_len); + +/** + * ecdh_shared_secret() - Compute a shared secret + * + * @curve_id: id representing the curve to use + * @private_key: private key of part A + * @private_key_len: length of private_key + * @public_key: public key of counterpart B + * @public_key_len: length of public_key + * @secret: buffer for storing the calculated shared secret + * @secret_len: length of the secret buffer + * + * Note: It is recommended that you hash the result of ecdh_shared_secret + * before using it for symmetric encryption or HMAC. + * + * Returns 0 if the shared secret was generated successfully, a negative value + * if an error occurred. + */ +int ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits, + const u8 *private_key, unsigned int private_key_len, + const u8 *public_key, unsigned int public_key_len, + u8 *secret, unsigned int secret_len); +#endif diff --git a/crypto/ecc_curve_defs.h b/crypto/ecc_curve_defs.h new file mode 100644 index 0000000..03ae5f7 --- /dev/null +++ b/crypto/ecc_curve_defs.h @@ -0,0 +1,57 @@ +#ifndef _CRYTO_ECC_CURVE_DEFS_H +#define _CRYTO_ECC_CURVE_DEFS_H + +struct ecc_point { + u64 *x; + u64 *y; + u8 ndigits; +}; + +struct ecc_curve { + char *name; + struct ecc_point g; + u64 *p; + u64 *n; +}; + +/* NIST P-192 */ +static u64 nist_p192_g_x[] = { 0xF4FF0AFD82FF1012ull, 0x7CBF20EB43A18800ull, + 0x188DA80EB03090F6ull }; +static u64 nist_p192_g_y[] = { 0x73F977A11E794811ull, 0x631011ED6B24CDD5ull, + 0x07192B95FFC8DA78ull }; +static u64 nist_p192_p[] = { 0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFEull, + 0xFFFFFFFFFFFFFFFFull }; +static u64 nist_p192_n[] = { 0x146BC9B1B4D22831ull, 0xFFFFFFFF99DEF836ull, + 0xFFFFFFFFFFFFFFFFull }; +static struct ecc_curve nist_p192 = { + .name = "nist_192", + .g = { + .x = nist_p192_g_x, + .y = nist_p192_g_y, + .ndigits = 3, + }, + .p = nist_p192_p, + .n = nist_p192_n +}; + +/* NIST P-256 */ +static u64 nist_p256_g_x[] = { 0xF4A13945D898C296ull, 0x77037D812DEB33A0ull, + 0xF8BCE6E563A440F2ull, 0x6B17D1F2E12C4247ull }; +static u64 nist_p256_g_y[] = { 0xCBB6406837BF51F5ull, 0x2BCE33576B315ECEull, + 0x8EE7EB4A7C0F9E16ull, 0x4FE342E2FE1A7F9Bull }; +static u64 nist_p256_p[] = { 0xFFFFFFFFFFFFFFFFull, 0x00000000FFFFFFFFull, + 0x0000000000000000ull, 0xFFFFFFFF00000001ull }; +static u64 nist_p256_n[] = { 0xF3B9CAC2FC632551ull, 0xBCE6FAADA7179E84ull, + 0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFF00000000ull }; +static struct ecc_curve nist_p256 = { + .name = "nist_256", + .g = { + .x = nist_p256_g_x, + .y = nist_p256_g_y, + .ndigits = 4, + }, + .p = nist_p256_p, + .n = nist_p256_n +}; + +#endif diff --git a/crypto/ecdh.c b/crypto/ecdh.c new file mode 100644 index 0000000..66bc2da --- /dev/null +++ b/crypto/ecdh.c @@ -0,0 +1,151 @@ +/* ECDH key-agreement protocol + * + * Copyright (c) 2016, Intel Corporation + * Authors: Salvator Benedetto + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include "ecc.h" + +struct ecdh_ctx { + unsigned int curve_id; + unsigned int ndigits; + u64 private_key[ECC_MAX_DIGITS]; + u64 public_key[2 * ECC_MAX_DIGITS]; + u64 shared_secret[ECC_MAX_DIGITS]; +}; + +static inline struct ecdh_ctx *ecdh_get_ctx(struct crypto_kpp *tfm) +{ + return kpp_tfm_ctx(tfm); +} + +static unsigned int ecdh_supported_curve(unsigned int curve_id) +{ + switch (curve_id) { + case ECC_CURVE_NIST_P192: return 3; + case ECC_CURVE_NIST_P256: return 4; + default: return 0; + } +} + +static int ecdh_set_secret(struct crypto_kpp *tfm, void *buf, unsigned int len) +{ + struct ecdh_ctx *ctx = ecdh_get_ctx(tfm); + struct ecdh *params = NULL; + unsigned int ndigits; + + if (crypto_ecdh_decode_key(buf, len, ¶ms) < 0) + return -EINVAL; + + ndigits = ecdh_supported_curve(params->curve_id); + if (!ndigits) + return -EINVAL; + + ctx->curve_id = params->curve_id; + ctx->ndigits = ndigits; + + if (ecc_is_key_valid(ctx->curve_id, ctx->ndigits, + (const u8 *)params->key, params->key_size) < 0) + return -EINVAL; + + memcpy(ctx->private_key, params->key, params->key_size); + + return 0; +} + +static int ecdh_compute_value(struct kpp_request *req) +{ + int ret = 0; + struct crypto_kpp *tfm = crypto_kpp_reqtfm(req); + struct ecdh_ctx *ctx = ecdh_get_ctx(tfm); + size_t copied, nbytes; + void *buf; + + nbytes = ctx->ndigits << ECC_DIGITS_TO_BYTES_SHIFT; + + if (req->src) { + copied = sg_copy_to_buffer(req->src, 1, ctx->public_key, + 2 * nbytes); + if (copied != 2 * nbytes) + return -EINVAL; + + ret = ecdh_shared_secret(ctx->curve_id, ctx->ndigits, + (const u8 *)ctx->private_key, nbytes, + (const u8 *)ctx->public_key, 2 * nbytes, + (u8 *)ctx->shared_secret, nbytes); + + buf = ctx->shared_secret; + } else { + ret = ecdh_make_pub_key(ctx->curve_id, ctx->ndigits, + (const u8 *)ctx->private_key, nbytes, + (u8 *)ctx->public_key, + sizeof(ctx->public_key)); + buf = ctx->public_key; + /* Public part is a point thus it has both coordinates */ + nbytes *= 2; + } + + if (ret < 0) + return ret; + + copied = sg_copy_from_buffer(req->dst, 1, buf, nbytes); + if (copied != nbytes) + return -EINVAL; + + return ret; +} + +static int ecdh_max_size(struct crypto_kpp *tfm) +{ + struct ecdh_ctx *ctx = ecdh_get_ctx(tfm); + int nbytes = ctx->ndigits << ECC_DIGITS_TO_BYTES_SHIFT; + + /* Public key is made of two coordinates */ + return 2 * nbytes; +} + +static void no_exit_tfm(struct crypto_kpp *tfm) +{ + return; +} + +static struct kpp_alg ecdh = { + .set_secret = ecdh_set_secret, + .generate_public_key = ecdh_compute_value, + .compute_shared_secret = ecdh_compute_value, + .max_size = ecdh_max_size, + .exit = no_exit_tfm, + .base = { + .cra_name = "ecdh", + .cra_driver_name = "ecdh-generic", + .cra_priority = 100, + .cra_module = THIS_MODULE, + .cra_ctxsize = sizeof(struct ecdh_ctx), + }, +}; + +static int ecdh_init(void) +{ + return crypto_register_kpp(&ecdh); +} + +static void ecdh_exit(void) +{ + crypto_unregister_kpp(&ecdh); +} + +module_init(ecdh_init); +module_exit(ecdh_exit); +MODULE_ALIAS_CRYPTO("ecdh"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("ECDH generic algorithm"); diff --git a/crypto/ecdh_helper.c b/crypto/ecdh_helper.c new file mode 100644 index 0000000..6155ac0 --- /dev/null +++ b/crypto/ecdh_helper.c @@ -0,0 +1,75 @@ +/* + * Copyright (c) 2016, Intel Corporation + * Authors: Salvatore Benedetto + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#include +#include +#include +#include +#include +#include + +static inline void *ecdh_key(const struct ecdh *params) +{ + return (void *)((u8 *)params + sizeof(*params)); +} + +static inline struct ecdh *ecdh_data(const struct kpp_secret *s) +{ + return (struct ecdh *)((u8 *)s + sizeof(*s)); +} + +int crypto_ecdh_key_len(const struct ecdh *params) +{ + return sizeof(struct kpp_secret) + sizeof(*params) + params->key_size; +} +EXPORT_SYMBOL_GPL(crypto_ecdh_key_len); + +int crypto_ecdh_encode_key(char *buf, unsigned int len, + const struct ecdh *params) +{ + struct kpp_secret *secret = (struct kpp_secret *)buf; + struct ecdh *data; + + if (unlikely(!buf)) + return -EINVAL; + + if (len != crypto_ecdh_key_len(params)) + return -EINVAL; + + secret->type = CRYPTO_KPP_SECRET_TYPE_ECDH; + secret->len = len; + + data = ecdh_data(secret); + data->curve_id = params->curve_id; + data->key_size = params->key_size; + data->key = ecdh_key(data); + + memcpy(data->key, params->key, params->key_size); + + return 0; +} +EXPORT_SYMBOL_GPL(crypto_ecdh_encode_key); + +int crypto_ecdh_decode_key(const char *buf, unsigned int len, + struct ecdh **params) +{ + struct kpp_secret *secret = (struct kpp_secret *)buf; + + if (unlikely(!secret)) + return -EINVAL; + if (secret->type != CRYPTO_KPP_SECRET_TYPE_ECDH) + return -EINVAL; + + *params = ecdh_data(secret); + if (secret->len != crypto_ecdh_key_len(*params)) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL_GPL(crypto_ecdh_decode_key); diff --git a/crypto/testmgr.c b/crypto/testmgr.c index e081473..25c139e 100644 --- a/crypto/testmgr.c +++ b/crypto/testmgr.c @@ -34,6 +34,7 @@ #include #include #include +#include #include "internal.h" @@ -123,7 +124,10 @@ struct akcipher_test_suite { }; struct kpp_test_suite { - struct kpp_testvec_dh *vecs; + union { + struct kpp_testvec_dh *dh; + struct kpp_testvec_ecdh *ecdh; + } vecs; unsigned int count; }; @@ -1942,12 +1946,153 @@ static int test_dh(struct crypto_kpp *tfm, struct kpp_testvec_dh *vecs, return 0; } -static int test_kpp(struct crypto_kpp *tfm, const char *alg, - struct kpp_testvec_dh *vecs, unsigned int tcount) +static int ecdh_key_len(const struct ecdh *params) +{ + return sizeof(struct kpp_secret) + sizeof(*params) + params->key_size; +} + +static int ecdh_encode_key(char *buf, unsigned int len, + const struct ecdh *params) +{ + struct kpp_secret *secret = (struct kpp_secret *)buf; + struct ecdh *data; + + if (len != ecdh_key_len(params)) + return -EINVAL; + + secret->type = CRYPTO_KPP_SECRET_TYPE_ECDH; + secret->len = len; + + data = (struct ecdh *)((u8 *)secret + sizeof(*secret)); + data->curve_id = params->curve_id; + data->key_size = params->key_size; + data->key = (void *)((u8 *)data + sizeof(*data)); + + memcpy(data->key, params->key, params->key_size); + + return 0; +} + +static int do_test_ecdh(struct crypto_kpp *tfm, struct kpp_testvec_ecdh *vec) +{ + struct kpp_request *req; + void *input_buf = NULL; + void *output_buf = NULL; + struct tcrypt_result result; + unsigned int out_len_max; + int err = -ENOMEM; + struct scatterlist src, dst; + struct ecdh p; + char *buf; + unsigned int len; + unsigned int nbytes = vec->ndigits << ECC_DIGITS_TO_BYTES_SHIFT; + + req = kpp_request_alloc(tfm, GFP_KERNEL); + if (!req) + return err; + + init_completion(&result.completion); + + /* Set curve_id */ + p.curve_id = vec->curve_id; + /* Set A private Key */ + p.key = vec->private_a; + p.key_size = nbytes; + + len = ecdh_key_len(&p); + buf = kmalloc(len, GFP_KERNEL); + if (!buf) + goto free_req; + + if (ecdh_encode_key(buf, len, &p) < 0) { + err = -EINVAL; + goto free_req; + } + err = crypto_kpp_set_secret(tfm, buf, len); + if (err) + goto free_buf; + + out_len_max = crypto_kpp_maxsize(tfm); + output_buf = kzalloc(out_len_max, GFP_KERNEL); + if (!output_buf) { + err = -ENOMEM; + goto free_buf; + } + + kpp_request_set_input(req, NULL, 0); + sg_init_one(&dst, output_buf, out_len_max); + kpp_request_set_output(req, &dst, out_len_max); + kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, + tcrypt_complete, &result); + + /* Compute A public key = aG mod p */ + err = wait_async_op(&result, crypto_kpp_generate_public_key(req)); + if (err) { + pr_err("alg: ecdh: generate public key test failed. err %d\n", + err); + goto free_output; + } + /* Verify calculated public key */ + if (memcmp(vec->expected_pub_a, sg_virt(req->dst), 2 * nbytes)) { + pr_err("alg: ecdh: generate public key test failed. Invalid output\n"); + err = -EINVAL; + goto free_output; + } + + /* Calculate shared secret key by using counter part public key. */ + input_buf = kzalloc(2 * nbytes, GFP_KERNEL); + if (!input_buf) { + err = -ENOMEM; + goto free_output; + } + + memcpy(input_buf, vec->public_b, 2 * nbytes); + sg_init_one(&src, input_buf, 2 * nbytes); + sg_init_one(&dst, output_buf, out_len_max); + kpp_request_set_input(req, &src, 2 * nbytes); + kpp_request_set_output(req, &dst, out_len_max); + kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, + tcrypt_complete, &result); + err = wait_async_op(&result, crypto_kpp_compute_shared_secret(req)); + if (err) { + pr_err("alg: ecdh: compute shard secret test failed. err %d\n", + err); + goto free_all; + } + + /* + * verify shared secret from which the user will derive + * secret key by executing whatever hash it has chosen + */ + if (memcmp(vec->expected_ss, sg_virt(req->dst), nbytes)) { + pr_err("alg: ecdh: compute shared secret test failed. Invalid output\n"); + err = -EINVAL; + } + +free_all: + kfree(input_buf); +free_output: + kfree(output_buf); +free_buf: + kfree(buf); +free_req: + kpp_request_free(req); + return err; +} + +static int test_ecdh(struct crypto_kpp *tfm, struct kpp_testvec_ecdh *vecs, + unsigned int tcount) { - if (strncmp(alg, "dh", 2) == 0) - return test_dh(tfm, vecs, tcount); + int ret, i; + for (i = 0; i < tcount; i++) { + ret = do_test_ecdh(tfm, vecs++); + if (ret) { + pr_err("alg: ecdh: test failed on vector %d, err=%d\n", + i + 1, ret); + return ret; + } + } return 0; } @@ -1963,9 +2108,12 @@ static int alg_test_kpp(const struct alg_test_desc *desc, const char *driver, driver, PTR_ERR(tfm)); return PTR_ERR(tfm); } - if (desc->suite.kpp.vecs) - err = test_kpp(tfm, desc->alg, desc->suite.kpp.vecs, - desc->suite.kpp.count); + if (!strncmp(desc->alg, "dh", 2) && desc->suite.kpp.vecs.dh) + err = test_dh(tfm, desc->suite.kpp.vecs.dh, + desc->suite.kpp.count); + else if (!strncmp(desc->alg, "ecdh", 4) && desc->suite.kpp.vecs.ecdh) + err = test_ecdh(tfm, desc->suite.kpp.vecs.ecdh, + desc->suite.kpp.count); crypto_free_kpp(tfm); return err; @@ -2928,7 +3076,7 @@ static const struct alg_test_desc alg_test_descs[] = { .fips_allowed = 1, .suite = { .kpp = { - .vecs = dh_tv_template, + .vecs.dh = dh_tv_template, .count = DH_TEST_VECTORS } } @@ -3361,6 +3509,16 @@ static const struct alg_test_desc alg_test_descs[] = { } } }, { + .alg = "ecdh", + .test = alg_test_kpp, + .fips_allowed = 1, + .suite = { + .kpp = { + .vecs.ecdh = ecdh_tv_template, + .count = ECDH_TEST_VECTORS + } + } + }, { .alg = "gcm(aes)", .test = alg_test_aead, .fips_allowed = 1, diff --git a/crypto/testmgr.h b/crypto/testmgr.h index e9c34c7..d2cbb54 100644 --- a/crypto/testmgr.h +++ b/crypto/testmgr.h @@ -26,6 +26,8 @@ #include +#include "ecc.h" + #define MAX_DIGEST_SIZE 64 #define MAX_TAP 8 @@ -148,6 +150,15 @@ struct kpp_testvec_dh { unsigned short expected_ss_size; }; +struct kpp_testvec_ecdh { + unsigned int curve_id; + char *private_a; + char *expected_pub_a; + char *public_b; + char *expected_ss; + unsigned short ndigits; +}; + static char zeroed_string[48]; /* @@ -538,6 +549,73 @@ struct kpp_testvec_dh dh_tv_template[] = { } }; +#ifdef CONFIG_CRYPTO_FIPS +#define ECDH_TEST_VECTORS 1 +#else +#define ECDH_TEST_VECTORS 2 +#endif +struct kpp_testvec_ecdh ecdh_tv_template[] = { + { +#ifndef CONFIG_CRYPTO_FIPS + .curve_id = ECC_CURVE_NIST_P192, + .private_a = + "\xb5\x05\xb1\x71\x1e\xbf\x8c\xda" + "\x4e\x19\x1e\x62\x1f\x23\x23\x31" + "\x36\x1e\xd3\x84\x2f\xcc\x21\x72", + .expected_pub_a = + "\x1a\x04\xdb\xa5\xe1\xdd\x4e\x79" + "\xa3\xe6\xef\x0e\x5c\x80\x49\x85" + "\xfa\x78\xb4\xef\x49\xbd\x4c\x7c" + "\x22\x90\x21\x02\xf9\x1b\x81\x5d" + "\x0c\x8a\xa8\x98\xd6\x27\x69\x88" + "\x5e\xbc\x94\xd8\x15\x9e\x21\xce", + .public_b = + "\xc3\xba\x67\x4b\x71\xec\xd0\x76" + "\x7a\x99\x75\x64\x36\x13\x9a\x94" + "\x5d\x8b\xdc\x60\x90\x91\xfd\x3f" + "\xb0\x1f\x8a\x0a\x68\xc6\x88\x6e" + "\x83\x87\xdd\x67\x09\xf8\x8d\x96" + "\x07\xd6\xbd\x1c\xe6\x8d\x9d\x67", + .expected_ss = + "\xf4\x57\xcc\x4f\x1f\x4e\x31\xcc" + "\xe3\x40\x60\xc8\x06\x93\xc6\x2e" + "\x99\x80\x81\x28\xaf\xc5\x51\x74", + .ndigits = 3, + }, { +#endif + .curve_id = ECC_CURVE_NIST_P256, + .private_a = + "\x24\xd1\x21\xeb\xe5\xcf\x2d\x83" + "\xf6\x62\x1b\x6e\x43\x84\x3a\xa3" + "\x8b\xe0\x86\xc3\x20\x19\xda\x92" + "\x50\x53\x03\xe1\xc0\xea\xb8\x82", + .expected_pub_a = + "\x1a\x7f\xeb\x52\x00\xbd\x3c\x31" + "\x7d\xb6\x70\xc1\x86\xa6\xc7\xc4" + "\x3b\xc5\x5f\x6c\x6f\x58\x3c\xf5" + "\xb6\x63\x82\x77\x33\x24\xa1\x5f" + "\x6a\xca\x43\x6f\xf7\x7e\xff\x02" + "\x37\x08\xcc\x40\x5e\x7a\xfd\x6a" + "\x6a\x02\x6e\x41\x87\x68\x38\x77" + "\xfa\xa9\x44\x43\x2d\xef\x09\xdf", + .public_b = + "\xcc\xb4\xda\x74\xb1\x47\x3f\xea" + "\x6c\x70\x9e\x38\x2d\xc7\xaa\xb7" + "\x29\xb2\x47\x03\x19\xab\xdd\x34" + "\xbd\xa8\x2c\x93\xe1\xa4\x74\xd9" + "\x64\x63\xf7\x70\x20\x2f\xa4\xe6" + "\x9f\x4a\x38\xcc\xc0\x2c\x49\x2f" + "\xb1\x32\xbb\xaf\x22\x61\xda\xcb" + "\x6f\xdb\xa9\xaa\xfc\x77\x81\xf3", + .expected_ss = + "\xea\x17\x6f\x7e\x6e\x57\x26\x38" + "\x8b\xfb\x41\xeb\xba\xc8\x6d\xa5" + "\xa8\x72\xd1\xff\xc9\x47\x3d\xaa" + "\x58\x43\x9f\x34\x0f\x8c\xf3\xc9", + .ndigits = 4, + } +}; + /* * MD4 test vectors from RFC1320 */ diff --git a/include/crypto/ecdh.h b/include/crypto/ecdh.h new file mode 100644 index 0000000..f848600 --- /dev/null +++ b/include/crypto/ecdh.h @@ -0,0 +1,30 @@ +/* + * ECDH params to be used with kpp API + * + * Copyright (c) 2016, Intel Corporation + * Authors: Salvatore Benedetto + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + */ +#ifndef _CRYPTO_ECDH_ +#define _CRYPTO_ECDH_ + +/* Curves IDs */ +#define ECC_CURVE_NIST_P192 0x0001 +#define ECC_CURVE_NIST_P256 0x0002 + +struct ecdh { + unsigned int curve_id; + char *key; + unsigned short key_size; +}; + +int crypto_ecdh_key_len(const struct ecdh *params); +int crypto_ecdh_encode_key(char *buf, unsigned int len, const struct ecdh *params); +int crypto_ecdh_decode_key(const char *buf, unsigned int len, struct ecdh **params); + +#endif diff --git a/include/crypto/kpp.h b/include/crypto/kpp.h index 937ac12..30791f7 100644 --- a/include/crypto/kpp.h +++ b/include/crypto/kpp.h @@ -243,6 +243,7 @@ static inline void kpp_request_set_output(struct kpp_request *req, enum { CRYPTO_KPP_SECRET_TYPE_UNKNOWN, CRYPTO_KPP_SECRET_TYPE_DH, + CRYPTO_KPP_SECRET_TYPE_ECDH, }; /** -- 2.7.4