8e79f2ee9c
Based on Nekogram. Key additions: - Rebrand to FoxiGram (app name, APK name, applicationId com.foxigram.app) - Embedded Xray (VLESS+Reality) proxy client via JNI libxray.so - Bundled hidden one-tap proxies (LTE + WiFi), read-only in UI - Auto-restore proxy on restart, rebind to active network (LTE/WiFi) - Server credentials externalized to git-ignored XrayServers.java (+ template) - libxray Go source included; compiled .so, keystore, google-services.json ignored
96 lines
3.6 KiB
C++
96 lines
3.6 KiB
C++
// Copyright 2019 The BoringSSL Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include <openssl/ec_key.h>
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#include <string.h>
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#include <openssl/ec.h>
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#include <openssl/err.h>
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#include <openssl/digest.h>
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#include <openssl/hkdf.h>
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#include <openssl/mem.h>
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#include "../fipsmodule/ec/internal.h"
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EC_KEY *EC_KEY_derive_from_secret(const EC_GROUP *group, const uint8_t *secret,
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size_t secret_len) {
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#define EC_KEY_DERIVE_MAX_NAME_LEN 16
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const char *name = EC_curve_nid2nist(EC_GROUP_get_curve_name(group));
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if (name == NULL || strlen(name) > EC_KEY_DERIVE_MAX_NAME_LEN) {
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OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP);
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return NULL;
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}
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// Assemble a label string to provide some key separation in case |secret| is
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// misused, but ultimately it's on the caller to ensure |secret| is suitably
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// separated.
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static const char kLabel[] = "derive EC key ";
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char info[sizeof(kLabel) + EC_KEY_DERIVE_MAX_NAME_LEN];
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OPENSSL_strlcpy(info, kLabel, sizeof(info));
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OPENSSL_strlcat(info, name, sizeof(info));
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// Generate 128 bits beyond the group order so the bias is at most 2^-128.
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#define EC_KEY_DERIVE_EXTRA_BITS 128
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#define EC_KEY_DERIVE_EXTRA_BYTES (EC_KEY_DERIVE_EXTRA_BITS / 8)
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if (EC_GROUP_order_bits(group) <= EC_KEY_DERIVE_EXTRA_BITS + 8) {
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// The reduction strategy below requires the group order be large enough.
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// (The actual bound is a bit tighter, but our curves are much larger than
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// 128-bit.)
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OPENSSL_PUT_ERROR(EC, ERR_R_INTERNAL_ERROR);
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return NULL;
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}
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uint8_t derived[EC_KEY_DERIVE_EXTRA_BYTES + EC_MAX_BYTES];
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size_t derived_len =
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BN_num_bytes(EC_GROUP_get0_order(group)) + EC_KEY_DERIVE_EXTRA_BYTES;
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assert(derived_len <= sizeof(derived));
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if (!HKDF(derived, derived_len, EVP_sha256(), secret, secret_len,
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/*salt=*/NULL, /*salt_len=*/0, (const uint8_t *)info,
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strlen(info))) {
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return NULL;
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}
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EC_KEY *key = EC_KEY_new();
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BN_CTX *ctx = BN_CTX_new();
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BIGNUM *priv = BN_bin2bn(derived, derived_len, NULL);
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EC_POINT *pub = EC_POINT_new(group);
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if (key == NULL || ctx == NULL || priv == NULL || pub == NULL ||
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// Reduce |priv| with Montgomery reduction. First, convert "from"
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// Montgomery form to compute |priv| * R^-1 mod |order|. This requires
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// |priv| be under order * R, which is true if the group order is large
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// enough. 2^(num_bytes(order)) < 2^8 * order, so:
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//
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// priv < 2^8 * order * 2^128 < order * order < order * R
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!BN_from_montgomery(priv, priv, &group->order, ctx) ||
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// Multiply by R^2 and do another Montgomery reduction to compute
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// priv * R^-1 * R^2 * R^-1 = priv mod order.
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!BN_to_montgomery(priv, priv, &group->order, ctx) ||
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!EC_POINT_mul(group, pub, priv, NULL, NULL, ctx) ||
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!EC_KEY_set_group(key, group) || !EC_KEY_set_public_key(key, pub) ||
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!EC_KEY_set_private_key(key, priv)) {
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EC_KEY_free(key);
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key = NULL;
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goto err;
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}
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err:
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OPENSSL_cleanse(derived, sizeof(derived));
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BN_CTX_free(ctx);
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BN_free(priv);
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EC_POINT_free(pub);
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return key;
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}
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