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@ -1,474 +0,0 @@
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From 0d39e4120bc5ece53c86c5802c546259b8ca286a Mon Sep 17 00:00:00 2001
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From: Daiki Ueno <ueno@gnu.org>
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Date: Fri, 12 Jan 2024 17:56:58 +0900
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Subject: [PATCH] nettle: avoid normalization of mpz_t in deterministic ECDSA
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This removes function calls that potentially leak bit-length of a
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private key used to calculate a nonce in deterministic ECDSA. Namely:
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- _gnutls_dsa_compute_k has been rewritten to work on always
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zero-padded mp_limb_t arrays instead of mpz_t
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- rnd_mpz_func has been replaced with rnd_datum_func, which is backed
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by a byte array instead of an mpz_t value
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Signed-off-by: Daiki Ueno <ueno@gnu.org>
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---
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lib/nettle/int/dsa-compute-k.c | 84 +++++++++++++++++++------------
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lib/nettle/int/dsa-compute-k.h | 31 +++++++++---
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lib/nettle/int/ecdsa-compute-k.c | 71 +++++++++-----------------
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lib/nettle/int/ecdsa-compute-k.h | 8 +--
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lib/nettle/pk.c | 79 ++++++++++++++++++++---------
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tests/sign-verify-deterministic.c | 2 +-
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6 files changed, 158 insertions(+), 117 deletions(-)
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diff --git a/lib/nettle/int/dsa-compute-k.c b/lib/nettle/int/dsa-compute-k.c
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index 17d63318c4..ddeb6f6d1e 100644
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--- a/lib/nettle/int/dsa-compute-k.c
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+++ b/lib/nettle/int/dsa-compute-k.c
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@@ -31,33 +31,37 @@
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#include "mpn-base256.h"
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#include <string.h>
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-#define BITS_TO_LIMBS(bits) (((bits) + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS)
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-
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-/* The maximum size of q, choosen from the fact that we support
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- * 521-bit elliptic curve generator and 512-bit DSA subgroup at
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- * maximum. */
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-#define MAX_Q_BITS 521
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-#define MAX_Q_SIZE ((MAX_Q_BITS + 7) / 8)
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-#define MAX_Q_LIMBS BITS_TO_LIMBS(MAX_Q_BITS)
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-
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-#define MAX_HASH_BITS (MAX_HASH_SIZE * 8)
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-#define MAX_HASH_LIMBS BITS_TO_LIMBS(MAX_HASH_BITS)
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-
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-int
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-_gnutls_dsa_compute_k(mpz_t k,
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- const mpz_t q,
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- const mpz_t x,
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- gnutls_mac_algorithm_t mac,
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- const uint8_t *digest,
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- size_t length)
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+/* For mini-gmp */
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+#ifndef GMP_LIMB_BITS
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+#define GMP_LIMB_BITS GMP_NUMB_BITS
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+#endif
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+
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+static inline int is_zero_limb(mp_limb_t x)
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+{
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+ x |= (x << 1);
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+ return ((x >> 1) - 1) >> (GMP_LIMB_BITS - 1);
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+}
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+
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+static int sec_zero_p(const mp_limb_t *ap, mp_size_t n)
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+{
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+ volatile mp_limb_t w;
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+ mp_size_t i;
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+
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+ for (i = 0, w = 0; i < n; i++)
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+ w |= ap[i];
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+
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+ return is_zero_limb(w);
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+}
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+
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+int _gnutls_dsa_compute_k(mp_limb_t *h, const mp_limb_t *q, const mp_limb_t *x,
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+ mp_size_t qn, mp_bitcnt_t q_bits,
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+ gnutls_mac_algorithm_t mac, const uint8_t *digest,
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+ size_t length)
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{
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uint8_t V[MAX_HASH_SIZE];
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uint8_t K[MAX_HASH_SIZE];
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uint8_t xp[MAX_Q_SIZE];
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uint8_t tp[MAX_Q_SIZE];
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- mp_limb_t h[MAX(MAX_Q_LIMBS, MAX_HASH_LIMBS)];
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- mp_bitcnt_t q_bits = mpz_sizeinbase (q, 2);
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- mp_size_t qn = mpz_size(q);
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mp_bitcnt_t h_bits = length * 8;
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mp_size_t hn = BITS_TO_LIMBS(h_bits);
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size_t nbytes = (q_bits + 7) / 8;
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@@ -66,6 +70,7 @@ _gnutls_dsa_compute_k(mpz_t k,
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mp_limb_t cy;
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gnutls_hmac_hd_t hd;
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int ret = 0;
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+ mp_limb_t scratch[MAX_Q_LIMBS];
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if (unlikely(q_bits > MAX_Q_BITS))
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return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
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@@ -73,7 +78,7 @@ _gnutls_dsa_compute_k(mpz_t k,
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return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
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/* int2octets(x) */
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- mpn_get_base256(xp, nbytes, mpz_limbs_read(x), qn);
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+ mpn_get_base256(xp, nbytes, x, qn);
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/* bits2octets(h) */
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mpn_set_base256(h, hn, digest, length);
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@@ -97,12 +102,12 @@ _gnutls_dsa_compute_k(mpz_t k,
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mpn_rshift(h, h, hn, shift % GMP_NUMB_BITS);
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}
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- cy = mpn_sub_n(h, h, mpz_limbs_read(q), qn);
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+ cy = mpn_sub_n(h, h, q, qn);
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/* Fall back to addmul_1, if nettle is linked with mini-gmp. */
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#ifdef mpn_cnd_add_n
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- mpn_cnd_add_n(cy, h, h, mpz_limbs_read(q), qn);
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+ mpn_cnd_add_n(cy, h, h, q, qn);
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#else
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- mpn_addmul_1(h, mpz_limbs_read(q), qn, cy != 0);
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+ mpn_addmul_1(h, q, qn, cy != 0);
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#endif
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mpn_get_base256(tp, nbytes, h, qn);
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@@ -178,12 +183,8 @@ _gnutls_dsa_compute_k(mpz_t k,
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if (tlen * 8 > q_bits)
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mpn_rshift (h, h, qn, tlen * 8 - q_bits);
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/* Check if k is in [1,q-1] */
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- if (!mpn_zero_p (h, qn) &&
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- mpn_cmp (h, mpz_limbs_read(q), qn) < 0) {
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- mpn_copyi(mpz_limbs_write(k, qn), h, qn);
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- mpz_limbs_finish(k, qn);
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+ if (!sec_zero_p(h, qn) && mpn_sub_n(scratch, h, q, qn))
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break;
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- }
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ret = gnutls_hmac_init(&hd, mac, K, length);
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if (ret < 0)
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@@ -207,3 +208,24 @@ _gnutls_dsa_compute_k(mpz_t k,
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return ret;
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}
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+
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+/* cancel-out dsa_sign's addition of 1 to random data */
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+void _gnutls_dsa_compute_k_finish(uint8_t *k, size_t nbytes, mp_limb_t *h,
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+ mp_size_t n)
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+{
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+ /* Fall back to sub_1, if nettle is linked with mini-gmp. */
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+#ifdef mpn_sec_sub_1
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+ mp_limb_t t[MAX_Q_LIMBS];
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+
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+ mpn_sec_sub_1(h, h, n, 1, t);
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+#else
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+ mpn_sub_1(h, h, n, 1);
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+#endif
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+ mpn_get_base256(k, nbytes, h, n);
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+}
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+
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+void _gnutls_ecdsa_compute_k_finish(uint8_t *k, size_t nbytes, mp_limb_t *h,
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+ mp_size_t n)
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+{
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+ mpn_get_base256(k, nbytes, h, n);
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+}
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diff --git a/lib/nettle/int/dsa-compute-k.h b/lib/nettle/int/dsa-compute-k.h
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index 64e90e0ca2..e88fce0a6d 100644
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--- a/lib/nettle/int/dsa-compute-k.h
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+++ b/lib/nettle/int/dsa-compute-k.h
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@@ -26,12 +26,29 @@
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#include <gnutls/gnutls.h>
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#include <nettle/bignum.h> /* includes gmp.h */
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-int
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-_gnutls_dsa_compute_k(mpz_t k,
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- const mpz_t q,
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- const mpz_t x,
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- gnutls_mac_algorithm_t mac,
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- const uint8_t *digest,
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- size_t length);
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+#define BITS_TO_LIMBS(bits) (((bits) + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS)
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+
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+/* The maximum size of q, chosen from the fact that we support
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+ * 521-bit elliptic curve generator and 512-bit DSA subgroup at
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+ * maximum. */
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+#define MAX_Q_BITS 521
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+#define MAX_Q_SIZE ((MAX_Q_BITS + 7) / 8)
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+#define MAX_Q_LIMBS BITS_TO_LIMBS(MAX_Q_BITS)
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+
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+#define MAX_HASH_BITS (MAX_HASH_SIZE * 8)
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+#define MAX_HASH_LIMBS BITS_TO_LIMBS(MAX_HASH_BITS)
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+
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+#define DSA_COMPUTE_K_ITCH MAX(MAX_Q_LIMBS, MAX_HASH_LIMBS)
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+
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+int _gnutls_dsa_compute_k(mp_limb_t *h, const mp_limb_t *q, const mp_limb_t *x,
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+ mp_size_t qn, mp_bitcnt_t q_bits,
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+ gnutls_mac_algorithm_t mac, const uint8_t *digest,
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+ size_t length);
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+
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+void _gnutls_dsa_compute_k_finish(uint8_t *k, size_t nbytes, mp_limb_t *h,
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+ mp_size_t n);
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+
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+void _gnutls_ecdsa_compute_k_finish(uint8_t *k, size_t nbytes, mp_limb_t *h,
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+ mp_size_t n);
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#endif /* GNUTLS_LIB_NETTLE_INT_DSA_COMPUTE_K_H */
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diff --git a/lib/nettle/int/ecdsa-compute-k.c b/lib/nettle/int/ecdsa-compute-k.c
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index 94914ebdfa..819302c1c7 100644
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--- a/lib/nettle/int/ecdsa-compute-k.c
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+++ b/lib/nettle/int/ecdsa-compute-k.c
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@@ -29,67 +29,46 @@
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#include "dsa-compute-k.h"
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#include "gnutls_int.h"
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-static inline int
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-_gnutls_ecc_curve_to_dsa_q(mpz_t *q, gnutls_ecc_curve_t curve)
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+int _gnutls_ecc_curve_to_dsa_q(mpz_t q, gnutls_ecc_curve_t curve)
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{
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switch (curve) {
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#ifdef ENABLE_NON_SUITEB_CURVES
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case GNUTLS_ECC_CURVE_SECP192R1:
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- mpz_init_set_str(*q,
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- "FFFFFFFFFFFFFFFFFFFFFFFF99DEF836"
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- "146BC9B1B4D22831",
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- 16);
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+ mpz_set_str(q,
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+ "FFFFFFFFFFFFFFFFFFFFFFFF99DEF836"
|
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+ "146BC9B1B4D22831",
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+ 16);
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return 0;
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case GNUTLS_ECC_CURVE_SECP224R1:
|
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- mpz_init_set_str(*q,
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- "FFFFFFFFFFFFFFFFFFFFFFFFFFFF16A2"
|
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- "E0B8F03E13DD29455C5C2A3D",
|
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- 16);
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+ mpz_set_str(q,
|
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+ "FFFFFFFFFFFFFFFFFFFFFFFFFFFF16A2"
|
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+ "E0B8F03E13DD29455C5C2A3D",
|
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+ 16);
|
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return 0;
|
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#endif
|
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case GNUTLS_ECC_CURVE_SECP256R1:
|
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- mpz_init_set_str(*q,
|
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- "FFFFFFFF00000000FFFFFFFFFFFFFFFF"
|
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- "BCE6FAADA7179E84F3B9CAC2FC632551",
|
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- 16);
|
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+ mpz_set_str(q,
|
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+ "FFFFFFFF00000000FFFFFFFFFFFFFFFF"
|
||||
+ "BCE6FAADA7179E84F3B9CAC2FC632551",
|
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+ 16);
|
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return 0;
|
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case GNUTLS_ECC_CURVE_SECP384R1:
|
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- mpz_init_set_str(*q,
|
||||
- "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
|
||||
- "FFFFFFFFFFFFFFFFC7634D81F4372DDF"
|
||||
- "581A0DB248B0A77AECEC196ACCC52973",
|
||||
- 16);
|
||||
+ mpz_set_str(q,
|
||||
+ "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
|
||||
+ "FFFFFFFFFFFFFFFFC7634D81F4372DDF"
|
||||
+ "581A0DB248B0A77AECEC196ACCC52973",
|
||||
+ 16);
|
||||
return 0;
|
||||
case GNUTLS_ECC_CURVE_SECP521R1:
|
||||
- mpz_init_set_str(*q,
|
||||
- "1FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
|
||||
- "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
|
||||
- "FFA51868783BF2F966B7FCC0148F709A"
|
||||
- "5D03BB5C9B8899C47AEBB6FB71E91386"
|
||||
- "409",
|
||||
- 16);
|
||||
+ mpz_set_str(q,
|
||||
+ "1FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
|
||||
+ "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
|
||||
+ "FFA51868783BF2F966B7FCC0148F709A"
|
||||
+ "5D03BB5C9B8899C47AEBB6FB71E91386"
|
||||
+ "409",
|
||||
+ 16);
|
||||
return 0;
|
||||
default:
|
||||
return gnutls_assert_val(GNUTLS_E_UNSUPPORTED_SIGNATURE_ALGORITHM);
|
||||
}
|
||||
}
|
||||
-
|
||||
-int
|
||||
-_gnutls_ecdsa_compute_k (mpz_t k,
|
||||
- gnutls_ecc_curve_t curve,
|
||||
- const mpz_t x,
|
||||
- gnutls_mac_algorithm_t mac,
|
||||
- const uint8_t *digest,
|
||||
- size_t length)
|
||||
-{
|
||||
- mpz_t q;
|
||||
- int ret;
|
||||
-
|
||||
- ret = _gnutls_ecc_curve_to_dsa_q(&q, curve);
|
||||
- if (ret < 0)
|
||||
- return gnutls_assert_val(ret);
|
||||
-
|
||||
- ret = _gnutls_dsa_compute_k (k, q, x, mac, digest, length);
|
||||
- mpz_clear(q);
|
||||
- return ret;
|
||||
-}
|
||||
diff --git a/lib/nettle/int/ecdsa-compute-k.h b/lib/nettle/int/ecdsa-compute-k.h
|
||||
index 7ca401d6e4..a7e612bcab 100644
|
||||
--- a/lib/nettle/int/ecdsa-compute-k.h
|
||||
+++ b/lib/nettle/int/ecdsa-compute-k.h
|
||||
@@ -26,12 +26,6 @@
|
||||
#include <gnutls/gnutls.h>
|
||||
#include <nettle/bignum.h> /* includes gmp.h */
|
||||
|
||||
-int
|
||||
-_gnutls_ecdsa_compute_k (mpz_t k,
|
||||
- gnutls_ecc_curve_t curve,
|
||||
- const mpz_t x,
|
||||
- gnutls_mac_algorithm_t mac,
|
||||
- const uint8_t *digest,
|
||||
- size_t length);
|
||||
+int _gnutls_ecc_curve_to_dsa_q(mpz_t q, gnutls_ecc_curve_t curve);
|
||||
|
||||
#endif /* GNUTLS_LIB_NETTLE_INT_ECDSA_COMPUTE_K_H */
|
||||
diff --git a/lib/nettle/pk.c b/lib/nettle/pk.c
|
||||
index 588e9df502..b19fe3804a 100644
|
||||
--- a/lib/nettle/pk.c
|
||||
+++ b/lib/nettle/pk.c
|
||||
@@ -102,10 +102,16 @@ static void rnd_nonce_func(void *_ctx, size_t length, uint8_t * data)
|
||||
}
|
||||
}
|
||||
|
||||
-static void rnd_mpz_func(void *_ctx, size_t length, uint8_t * data)
|
||||
+static void rnd_datum_func(void *ctx, size_t length, uint8_t *data)
|
||||
{
|
||||
- mpz_t *k = _ctx;
|
||||
- nettle_mpz_get_str_256 (length, data, *k);
|
||||
+ gnutls_datum_t *d = ctx;
|
||||
+
|
||||
+ if (length > d->size) {
|
||||
+ memset(data, 0, length - d->size);
|
||||
+ memcpy(data + (length - d->size), d->data, d->size);
|
||||
+ } else {
|
||||
+ memcpy(data, d->data, length);
|
||||
+ }
|
||||
}
|
||||
|
||||
static void rnd_nonce_func_fallback(void *_ctx, size_t length, uint8_t * data)
|
||||
@@ -976,7 +982,10 @@ _wrap_nettle_pk_sign(gnutls_pk_algorithm_t algo,
|
||||
struct dsa_signature sig;
|
||||
int curve_id = pk_params->curve;
|
||||
const struct ecc_curve *curve;
|
||||
- mpz_t k;
|
||||
+ mpz_t q;
|
||||
+ /* 521-bit elliptic curve generator at maximum */
|
||||
+ uint8_t buf[(521 + 7) / 8];
|
||||
+ gnutls_datum_t k = { NULL, 0 };
|
||||
void *random_ctx;
|
||||
nettle_random_func *random_func;
|
||||
|
||||
@@ -1005,19 +1014,32 @@ _wrap_nettle_pk_sign(gnutls_pk_algorithm_t algo,
|
||||
hash_len = vdata->size;
|
||||
}
|
||||
|
||||
- mpz_init(k);
|
||||
+ mpz_init(q);
|
||||
+
|
||||
if (_gnutls_get_lib_state() == LIB_STATE_SELFTEST ||
|
||||
(sign_params->flags & GNUTLS_PK_FLAG_REPRODUCIBLE)) {
|
||||
- ret = _gnutls_ecdsa_compute_k(k,
|
||||
- curve_id,
|
||||
- pk_params->params[ECC_K],
|
||||
- DIG_TO_MAC(sign_params->dsa_dig),
|
||||
- vdata->data,
|
||||
- vdata->size);
|
||||
+ mp_limb_t h[DSA_COMPUTE_K_ITCH];
|
||||
+
|
||||
+ ret = _gnutls_ecc_curve_to_dsa_q(q, curve_id);
|
||||
if (ret < 0)
|
||||
goto ecdsa_cleanup;
|
||||
+
|
||||
+ ret = _gnutls_dsa_compute_k(
|
||||
+ h, mpz_limbs_read(q), priv.p,
|
||||
+ ecc_size(priv.ecc), ecc_bit_size(priv.ecc),
|
||||
+ DIG_TO_MAC(sign_params->dsa_dig), vdata->data,
|
||||
+ vdata->size);
|
||||
+ if (ret < 0)
|
||||
+ goto ecdsa_cleanup;
|
||||
+
|
||||
+ k.data = buf;
|
||||
+ k.size = (ecc_bit_size(priv.ecc) + 7) / 8;
|
||||
+
|
||||
+ _gnutls_ecdsa_compute_k_finish(k.data, k.size, h,
|
||||
+ ecc_size(priv.ecc));
|
||||
+
|
||||
random_ctx = &k;
|
||||
- random_func = rnd_mpz_func;
|
||||
+ random_func = rnd_datum_func;
|
||||
} else {
|
||||
random_ctx = NULL;
|
||||
random_func = rnd_nonce_func;
|
||||
@@ -1038,7 +1060,7 @@ _wrap_nettle_pk_sign(gnutls_pk_algorithm_t algo,
|
||||
ecdsa_cleanup:
|
||||
dsa_signature_clear(&sig);
|
||||
ecc_scalar_zclear(&priv);
|
||||
- mpz_clear(k);
|
||||
+ mpz_clear(q);
|
||||
|
||||
if (ret < 0) {
|
||||
gnutls_assert();
|
||||
@@ -1051,7 +1073,9 @@ _wrap_nettle_pk_sign(gnutls_pk_algorithm_t algo,
|
||||
struct dsa_params pub;
|
||||
bigint_t priv;
|
||||
struct dsa_signature sig;
|
||||
- mpz_t k;
|
||||
+ /* 512-bit DSA subgroup at maximum */
|
||||
+ uint8_t buf[(512 + 7) / 8];
|
||||
+ gnutls_datum_t k = { NULL, 0 };
|
||||
void *random_ctx;
|
||||
nettle_random_func *random_func;
|
||||
|
||||
@@ -1074,21 +1098,27 @@ _wrap_nettle_pk_sign(gnutls_pk_algorithm_t algo,
|
||||
hash_len = vdata->size;
|
||||
}
|
||||
|
||||
- mpz_init(k);
|
||||
if (_gnutls_get_lib_state() == LIB_STATE_SELFTEST ||
|
||||
(sign_params->flags & GNUTLS_PK_FLAG_REPRODUCIBLE)) {
|
||||
- ret = _gnutls_dsa_compute_k(k,
|
||||
- pub.q,
|
||||
- TOMPZ(priv),
|
||||
- DIG_TO_MAC(sign_params->dsa_dig),
|
||||
- vdata->data,
|
||||
- vdata->size);
|
||||
+ mp_limb_t h[DSA_COMPUTE_K_ITCH];
|
||||
+
|
||||
+ ret = _gnutls_dsa_compute_k(
|
||||
+ h, mpz_limbs_read(pub.q),
|
||||
+ mpz_limbs_read(TOMPZ(priv)), mpz_size(pub.q),
|
||||
+ mpz_sizeinbase(pub.q, 2),
|
||||
+ DIG_TO_MAC(sign_params->dsa_dig), vdata->data,
|
||||
+ vdata->size);
|
||||
if (ret < 0)
|
||||
goto dsa_fail;
|
||||
- /* cancel-out dsa_sign's addition of 1 to random data */
|
||||
- mpz_sub_ui (k, k, 1);
|
||||
+
|
||||
+ k.data = buf;
|
||||
+ k.size = (mpz_sizeinbase(pub.q, 2) + 7) / 8;
|
||||
+
|
||||
+ _gnutls_dsa_compute_k_finish(k.data, k.size, h,
|
||||
+ mpz_size(pub.q));
|
||||
+
|
||||
random_ctx = &k;
|
||||
- random_func = rnd_mpz_func;
|
||||
+ random_func = rnd_datum_func;
|
||||
} else {
|
||||
random_ctx = NULL;
|
||||
random_func = rnd_nonce_func;
|
||||
@@ -1108,7 +1138,6 @@ _wrap_nettle_pk_sign(gnutls_pk_algorithm_t algo,
|
||||
|
||||
dsa_fail:
|
||||
dsa_signature_clear(&sig);
|
||||
- mpz_clear(k);
|
||||
|
||||
if (ret < 0) {
|
||||
gnutls_assert();
|
||||
diff --git a/tests/sign-verify-deterministic.c b/tests/sign-verify-deterministic.c
|
||||
index 6e907288ee..25aa553a59 100644
|
||||
--- a/tests/sign-verify-deterministic.c
|
||||
+++ b/tests/sign-verify-deterministic.c
|
||||
@@ -197,7 +197,7 @@ void doit(void)
|
||||
&signature);
|
||||
if (ret < 0)
|
||||
testfail("gnutls_pubkey_verify_data2\n");
|
||||
- success(" - pass");
|
||||
+ success(" - pass\n");
|
||||
|
||||
next:
|
||||
gnutls_free(signature.data);
|
||||
--
|
||||
2.44.0
|
||||
|
@ -1,121 +0,0 @@
|
||||
From fe912c5dba49dcecbd5c32bf8184e60a949af452 Mon Sep 17 00:00:00 2001
|
||||
From: Daiki Ueno <ueno@gnu.org>
|
||||
Date: Wed, 10 Jan 2024 19:13:17 +0900
|
||||
Subject: [PATCH] rsa-psk: minimize branching after decryption
|
||||
|
||||
This moves any non-trivial code between gnutls_privkey_decrypt_data2
|
||||
and the function return in _gnutls_proc_rsa_psk_client_kx up until the
|
||||
decryption. This also avoids an extra memcpy to session->key.key.
|
||||
|
||||
Signed-off-by: Daiki Ueno <ueno@gnu.org>
|
||||
---
|
||||
lib/auth/rsa_psk.c | 68 ++++++++++++++++++++++++----------------------
|
||||
1 file changed, 35 insertions(+), 33 deletions(-)
|
||||
|
||||
diff --git a/lib/auth/rsa_psk.c b/lib/auth/rsa_psk.c
|
||||
index 93c2dc9998..8f3fe5a4bd 100644
|
||||
--- a/lib/auth/rsa_psk.c
|
||||
+++ b/lib/auth/rsa_psk.c
|
||||
@@ -269,7 +269,6 @@ _gnutls_proc_rsa_psk_client_kx(gnutls_session_t session, uint8_t * data,
|
||||
int ret, dsize;
|
||||
ssize_t data_size = _data_size;
|
||||
gnutls_psk_server_credentials_t cred;
|
||||
- gnutls_datum_t premaster_secret = { NULL, 0 };
|
||||
volatile uint8_t ver_maj, ver_min;
|
||||
|
||||
cred = (gnutls_psk_server_credentials_t)
|
||||
@@ -329,24 +328,48 @@ _gnutls_proc_rsa_psk_client_kx(gnutls_session_t session, uint8_t * data,
|
||||
ver_maj = _gnutls_get_adv_version_major(session);
|
||||
ver_min = _gnutls_get_adv_version_minor(session);
|
||||
|
||||
- premaster_secret.data = gnutls_malloc(GNUTLS_MASTER_SIZE);
|
||||
- if (premaster_secret.data == NULL) {
|
||||
+ /* Find the key of this username. A random value will be
|
||||
+ * filled in if the key is not found.
|
||||
+ */
|
||||
+ ret =
|
||||
+ _gnutls_psk_pwd_find_entry(session, info->username, strlen(info->username), &pwd_psk);
|
||||
+ if (ret < 0)
|
||||
+ return gnutls_assert_val(ret);
|
||||
+
|
||||
+ /* Allocate memory for premaster secret, and fill in the
|
||||
+ * fields except the decryption result.
|
||||
+ */
|
||||
+ session->key.key.size = 2 + GNUTLS_MASTER_SIZE + 2 + pwd_psk.size;
|
||||
+ session->key.key.data = gnutls_malloc(session->key.key.size);
|
||||
+ if (session->key.key.data == NULL) {
|
||||
gnutls_assert();
|
||||
+ _gnutls_free_key_datum(&pwd_psk);
|
||||
+ /* No need to zeroize, as the secret is not copied in yet */
|
||||
+ _gnutls_free_datum(&session->key.key);
|
||||
return GNUTLS_E_MEMORY_ERROR;
|
||||
}
|
||||
- premaster_secret.size = GNUTLS_MASTER_SIZE;
|
||||
|
||||
/* Fallback value when decryption fails. Needs to be unpredictable. */
|
||||
- ret = gnutls_rnd(GNUTLS_RND_NONCE, premaster_secret.data,
|
||||
- premaster_secret.size);
|
||||
+ ret = gnutls_rnd(GNUTLS_RND_NONCE, session->key.key.data + 2,
|
||||
+ GNUTLS_MASTER_SIZE);
|
||||
if (ret < 0) {
|
||||
gnutls_assert();
|
||||
- goto cleanup;
|
||||
+ _gnutls_free_key_datum(&pwd_psk);
|
||||
+ /* No need to zeroize, as the secret is not copied in yet */
|
||||
+ _gnutls_free_datum(&session->key.key);
|
||||
+ return ret;
|
||||
}
|
||||
|
||||
+ _gnutls_write_uint16(GNUTLS_MASTER_SIZE, session->key.key.data);
|
||||
+ _gnutls_write_uint16(pwd_psk.size,
|
||||
+ &session->key.key.data[2 + GNUTLS_MASTER_SIZE]);
|
||||
+ memcpy(&session->key.key.data[2 + GNUTLS_MASTER_SIZE + 2],
|
||||
+ pwd_psk.data, pwd_psk.size);
|
||||
+ _gnutls_free_key_datum(&pwd_psk);
|
||||
+
|
||||
gnutls_privkey_decrypt_data2(session->internals.selected_key, 0,
|
||||
- &ciphertext, premaster_secret.data,
|
||||
- premaster_secret.size);
|
||||
+ &ciphertext, session->key.key.data + 2,
|
||||
+ GNUTLS_MASTER_SIZE);
|
||||
/* After this point, any conditional on failure that cause differences
|
||||
* in execution may create a timing or cache access pattern side
|
||||
* channel that can be used as an oracle, so tread carefully */
|
||||
@@ -365,31 +388,10 @@ _gnutls_proc_rsa_psk_client_kx(gnutls_session_t session, uint8_t * data,
|
||||
/* This is here to avoid the version check attack
|
||||
* discussed above.
|
||||
*/
|
||||
- premaster_secret.data[0] = ver_maj;
|
||||
- premaster_secret.data[1] = ver_min;
|
||||
-
|
||||
- /* find the key of this username
|
||||
- */
|
||||
- ret =
|
||||
- _gnutls_psk_pwd_find_entry(session, info->username, strlen(info->username), &pwd_psk);
|
||||
- if (ret < 0) {
|
||||
- gnutls_assert();
|
||||
- goto cleanup;
|
||||
- }
|
||||
-
|
||||
- ret =
|
||||
- set_rsa_psk_session_key(session, &pwd_psk, &premaster_secret);
|
||||
- if (ret < 0) {
|
||||
- gnutls_assert();
|
||||
- goto cleanup;
|
||||
- }
|
||||
+ session->key.key.data[2] = ver_maj;
|
||||
+ session->key.key.data[3] = ver_min;
|
||||
|
||||
- ret = 0;
|
||||
- cleanup:
|
||||
- _gnutls_free_key_datum(&pwd_psk);
|
||||
- _gnutls_free_temp_key_datum(&premaster_secret);
|
||||
-
|
||||
- return ret;
|
||||
+ return 0;
|
||||
}
|
||||
|
||||
static int
|
||||
--
|
||||
2.43.0
|
||||
|
@ -1,202 +0,0 @@
|
||||
From e007a54432c98618bde500649817d153225abf6b Mon Sep 17 00:00:00 2001
|
||||
From: rpm-build <rpm-build>
|
||||
Date: Thu, 7 Dec 2023 11:52:08 +0900
|
||||
Subject: [PATCH] gnutls-3.6.16-rsa-psk-timing.patch
|
||||
|
||||
Signed-off-by: rpm-build <rpm-build>
|
||||
---
|
||||
lib/auth/rsa.c | 2 +-
|
||||
lib/auth/rsa_psk.c | 93 +++++++++++++++++-----------------------------
|
||||
lib/gnutls_int.h | 4 --
|
||||
lib/priority.c | 1 -
|
||||
4 files changed, 35 insertions(+), 65 deletions(-)
|
||||
|
||||
diff --git a/lib/auth/rsa.c b/lib/auth/rsa.c
|
||||
index 858701f..02b6a34 100644
|
||||
--- a/lib/auth/rsa.c
|
||||
+++ b/lib/auth/rsa.c
|
||||
@@ -207,7 +207,7 @@ proc_rsa_client_kx(gnutls_session_t session, uint8_t * data,
|
||||
session->key.key.size);
|
||||
/* After this point, any conditional on failure that cause differences
|
||||
* in execution may create a timing or cache access pattern side
|
||||
- * channel that can be used as an oracle, so treat very carefully */
|
||||
+ * channel that can be used as an oracle, so tread carefully */
|
||||
|
||||
/* Error handling logic:
|
||||
* In case decryption fails then don't inform the peer. Just use the
|
||||
diff --git a/lib/auth/rsa_psk.c b/lib/auth/rsa_psk.c
|
||||
index 1a9dab5..93c2dc9 100644
|
||||
--- a/lib/auth/rsa_psk.c
|
||||
+++ b/lib/auth/rsa_psk.c
|
||||
@@ -264,14 +264,13 @@ _gnutls_proc_rsa_psk_client_kx(gnutls_session_t session, uint8_t * data,
|
||||
{
|
||||
gnutls_datum_t username;
|
||||
psk_auth_info_t info;
|
||||
- gnutls_datum_t plaintext;
|
||||
gnutls_datum_t ciphertext;
|
||||
gnutls_datum_t pwd_psk = { NULL, 0 };
|
||||
int ret, dsize;
|
||||
- int randomize_key = 0;
|
||||
ssize_t data_size = _data_size;
|
||||
gnutls_psk_server_credentials_t cred;
|
||||
gnutls_datum_t premaster_secret = { NULL, 0 };
|
||||
+ volatile uint8_t ver_maj, ver_min;
|
||||
|
||||
cred = (gnutls_psk_server_credentials_t)
|
||||
_gnutls_get_cred(session, GNUTLS_CRD_PSK);
|
||||
@@ -327,71 +326,47 @@ _gnutls_proc_rsa_psk_client_kx(gnutls_session_t session, uint8_t * data,
|
||||
}
|
||||
ciphertext.size = dsize;
|
||||
|
||||
- ret =
|
||||
- gnutls_privkey_decrypt_data(session->internals.selected_key, 0,
|
||||
- &ciphertext, &plaintext);
|
||||
- if (ret < 0 || plaintext.size != GNUTLS_MASTER_SIZE) {
|
||||
- /* In case decryption fails then don't inform
|
||||
- * the peer. Just use a random key. (in order to avoid
|
||||
- * attack against pkcs-1 formatting).
|
||||
- */
|
||||
+ ver_maj = _gnutls_get_adv_version_major(session);
|
||||
+ ver_min = _gnutls_get_adv_version_minor(session);
|
||||
+
|
||||
+ premaster_secret.data = gnutls_malloc(GNUTLS_MASTER_SIZE);
|
||||
+ if (premaster_secret.data == NULL) {
|
||||
gnutls_assert();
|
||||
- _gnutls_debug_log
|
||||
- ("auth_rsa_psk: Possible PKCS #1 format attack\n");
|
||||
- if (ret >= 0) {
|
||||
- gnutls_free(plaintext.data);
|
||||
- }
|
||||
- randomize_key = 1;
|
||||
- } else {
|
||||
- /* If the secret was properly formatted, then
|
||||
- * check the version number.
|
||||
- */
|
||||
- if (_gnutls_get_adv_version_major(session) !=
|
||||
- plaintext.data[0]
|
||||
- || (session->internals.allow_wrong_pms == 0
|
||||
- && _gnutls_get_adv_version_minor(session) !=
|
||||
- plaintext.data[1])) {
|
||||
- /* No error is returned here, if the version number check
|
||||
- * fails. We proceed normally.
|
||||
- * That is to defend against the attack described in the paper
|
||||
- * "Attacking RSA-based sessions in SSL/TLS" by Vlastimil Klima,
|
||||
- * Ondej Pokorny and Tomas Rosa.
|
||||
- */
|
||||
- gnutls_assert();
|
||||
- _gnutls_debug_log
|
||||
- ("auth_rsa: Possible PKCS #1 version check format attack\n");
|
||||
- }
|
||||
+ return GNUTLS_E_MEMORY_ERROR;
|
||||
}
|
||||
+ premaster_secret.size = GNUTLS_MASTER_SIZE;
|
||||
|
||||
-
|
||||
- if (randomize_key != 0) {
|
||||
- premaster_secret.size = GNUTLS_MASTER_SIZE;
|
||||
- premaster_secret.data =
|
||||
- gnutls_malloc(premaster_secret.size);
|
||||
- if (premaster_secret.data == NULL) {
|
||||
- gnutls_assert();
|
||||
- return GNUTLS_E_MEMORY_ERROR;
|
||||
- }
|
||||
-
|
||||
- /* we do not need strong random numbers here.
|
||||
- */
|
||||
- ret = gnutls_rnd(GNUTLS_RND_NONCE, premaster_secret.data,
|
||||
- premaster_secret.size);
|
||||
- if (ret < 0) {
|
||||
- gnutls_assert();
|
||||
- goto cleanup;
|
||||
- }
|
||||
- } else {
|
||||
- premaster_secret.data = plaintext.data;
|
||||
- premaster_secret.size = plaintext.size;
|
||||
+ /* Fallback value when decryption fails. Needs to be unpredictable. */
|
||||
+ ret = gnutls_rnd(GNUTLS_RND_NONCE, premaster_secret.data,
|
||||
+ premaster_secret.size);
|
||||
+ if (ret < 0) {
|
||||
+ gnutls_assert();
|
||||
+ goto cleanup;
|
||||
}
|
||||
|
||||
+ gnutls_privkey_decrypt_data2(session->internals.selected_key, 0,
|
||||
+ &ciphertext, premaster_secret.data,
|
||||
+ premaster_secret.size);
|
||||
+ /* After this point, any conditional on failure that cause differences
|
||||
+ * in execution may create a timing or cache access pattern side
|
||||
+ * channel that can be used as an oracle, so tread carefully */
|
||||
+
|
||||
+ /* Error handling logic:
|
||||
+ * In case decryption fails then don't inform the peer. Just use the
|
||||
+ * random key previously generated. (in order to avoid attack against
|
||||
+ * pkcs-1 formatting).
|
||||
+ *
|
||||
+ * If we get version mismatches no error is returned either. We
|
||||
+ * proceed normally. This is to defend against the attack described
|
||||
+ * in the paper "Attacking RSA-based sessions in SSL/TLS" by
|
||||
+ * Vlastimil Klima, Ondej Pokorny and Tomas Rosa.
|
||||
+ */
|
||||
+
|
||||
/* This is here to avoid the version check attack
|
||||
* discussed above.
|
||||
*/
|
||||
-
|
||||
- premaster_secret.data[0] = _gnutls_get_adv_version_major(session);
|
||||
- premaster_secret.data[1] = _gnutls_get_adv_version_minor(session);
|
||||
+ premaster_secret.data[0] = ver_maj;
|
||||
+ premaster_secret.data[1] = ver_min;
|
||||
|
||||
/* find the key of this username
|
||||
*/
|
||||
diff --git a/lib/gnutls_int.h b/lib/gnutls_int.h
|
||||
index 31cec5c..815f69b 100644
|
||||
--- a/lib/gnutls_int.h
|
||||
+++ b/lib/gnutls_int.h
|
||||
@@ -971,7 +971,6 @@ struct gnutls_priority_st {
|
||||
bool _no_etm;
|
||||
bool _no_ext_master_secret;
|
||||
bool _allow_key_usage_violation;
|
||||
- bool _allow_wrong_pms;
|
||||
bool _dumbfw;
|
||||
unsigned int _dh_prime_bits; /* old (deprecated) variable */
|
||||
|
||||
@@ -989,7 +988,6 @@ struct gnutls_priority_st {
|
||||
(x)->no_etm = 1; \
|
||||
(x)->no_ext_master_secret = 1; \
|
||||
(x)->allow_key_usage_violation = 1; \
|
||||
- (x)->allow_wrong_pms = 1; \
|
||||
(x)->dumbfw = 1
|
||||
|
||||
#define ENABLE_PRIO_COMPAT(x) \
|
||||
@@ -998,7 +996,6 @@ struct gnutls_priority_st {
|
||||
(x)->_no_etm = 1; \
|
||||
(x)->_no_ext_master_secret = 1; \
|
||||
(x)->_allow_key_usage_violation = 1; \
|
||||
- (x)->_allow_wrong_pms = 1; \
|
||||
(x)->_dumbfw = 1
|
||||
|
||||
/* DH and RSA parameters types.
|
||||
@@ -1123,7 +1120,6 @@ typedef struct {
|
||||
bool no_etm;
|
||||
bool no_ext_master_secret;
|
||||
bool allow_key_usage_violation;
|
||||
- bool allow_wrong_pms;
|
||||
bool dumbfw;
|
||||
|
||||
/* old (deprecated) variable. This is used for both srp_prime_bits
|
||||
diff --git a/lib/priority.c b/lib/priority.c
|
||||
index 0a284ae..67ec887 100644
|
||||
--- a/lib/priority.c
|
||||
+++ b/lib/priority.c
|
||||
@@ -681,7 +681,6 @@ gnutls_priority_set(gnutls_session_t session, gnutls_priority_t priority)
|
||||
COPY_TO_INTERNALS(no_etm);
|
||||
COPY_TO_INTERNALS(no_ext_master_secret);
|
||||
COPY_TO_INTERNALS(allow_key_usage_violation);
|
||||
- COPY_TO_INTERNALS(allow_wrong_pms);
|
||||
COPY_TO_INTERNALS(dumbfw);
|
||||
COPY_TO_INTERNALS(dh_prime_bits);
|
||||
|
||||
--
|
||||
2.43.0
|
||||
|
@ -1,5 +1,5 @@
|
||||
Version: 3.6.16
|
||||
Release: 8%{?dist}.3
|
||||
Release: 7%{?dist}
|
||||
Patch1: gnutls-3.2.7-rpath.patch
|
||||
Patch2: gnutls-3.6.4-no-now-guile.patch
|
||||
Patch3: gnutls-3.6.13-enable-intel-cet.patch
|
||||
@ -12,9 +12,6 @@ Patch15: gnutls-3.6.16-pkcs7-verify.patch
|
||||
Patch16: gnutls-3.6.16-cpuid.patch
|
||||
Patch17: gnutls-3.7.8-rsa-kx-timing.patch
|
||||
Patch18: gnutls-3.6.16-rehandshake-tickets.patch
|
||||
Patch19: gnutls-3.6.16-rsa-psk-timing.patch
|
||||
Patch20: gnutls-3.6.16-rsa-psk-timing-followup.patch
|
||||
Patch21: gnutls-3.6.16-deterministic-ecdsa-fixes.patch
|
||||
%bcond_without dane
|
||||
%if 0%{?rhel}
|
||||
%bcond_with guile
|
||||
@ -299,18 +296,6 @@ fi
|
||||
%endif
|
||||
|
||||
%changelog
|
||||
* Tue Mar 26 2024 Daiki Ueno <dueno@redhat.com> - 3.6.16-8.3
|
||||
- Fix memleak with older GMP (RHEL-28957)
|
||||
|
||||
* Mon Mar 25 2024 Daiki Ueno <dueno@redhat.com> - 3.6.16-8.2
|
||||
- Fix timing side-channel in deterministic ECDSA (RHEL-28957)
|
||||
|
||||
* Thu Jan 18 2024 Daiki Ueno <dueno@redhat.com> - 3.6.16-8.1
|
||||
- auth/rsa-psk: minimize branching after decryption (RHEL-21586)
|
||||
|
||||
* Wed Dec 6 2023 Daiki Ueno <dueno@redhat.com> - 3.6.16-8
|
||||
- auth/rsa_psk: side-step potential side-channel (RHEL-16753)
|
||||
|
||||
* Mon Jun 26 2023 Daiki Ueno <dueno@redhat.com> - 3.6.16-7
|
||||
- Clear server's session ticket indication at rehandshake (#2089817)
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user