lib/net: Implement a reusable fingerprint database

src/lib/net/FingerprintDatabase.cpp

@@ -0,0 +1,140 @@
+/*
+    barrier -- mouse and keyboard sharing utility
+    Copyright (C) Barrier contributors
+
+    This package is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    found in the file LICENSE that should have accompanied this file.
+
+    This package is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "base/String.h"
+#include "FingerprintDatabase.h"
+#include "io/fstream.h"
+#include <algorithm>
+#include <fstream>
+
+namespace barrier {
+
+bool FingerprintData::operator==(const FingerprintData& other) const
+{
+    return algorithm == other.algorithm && data == other.data;
+}
+
+void FingerprintDatabase::read(const std::string& path)
+{
+    std::ifstream file;
+    open_utf8_path(file, path, std::ios_base::in);
+    read_stream(file);
+}
+
+void FingerprintDatabase::write(const std::string& path)
+{
+    std::ofstream file;
+    open_utf8_path(file, path, std::ios_base::out);
+    write_stream(file);
+}
+
+void FingerprintDatabase::read_stream(std::istream& stream)
+{
+    if (!stream.good()) {
+        return;
+    }
+
+    std::string line;
+    while (std::getline(stream, line)) {
+        if (line.empty()) {
+            continue;
+        }
+
+        auto fingerprint = parse_db_line(line);
+        if (!fingerprint.valid()) {
+            continue;
+        }
+
+        fingerprints_.push_back(fingerprint);
+    }
+}
+
+void FingerprintDatabase::write_stream(std::ostream& stream)
+{
+    if (!stream.good()) {
+        return;
+    }
+
+    for (const auto& fingerprint : fingerprints_) {
+        stream << to_db_line(fingerprint) << "\n";
+    }
+}
+
+void FingerprintDatabase::clear()
+{
+    fingerprints_.clear();
+}
+
+void FingerprintDatabase::add_trusted(const FingerprintData& fingerprint)
+{
+    if (is_trusted(fingerprint)) {
+        return;
+    }
+    fingerprints_.push_back(fingerprint);
+}
+
+bool FingerprintDatabase::is_trusted(const FingerprintData& fingerprint)
+{
+    auto found_it = std::find(fingerprints_.begin(), fingerprints_.end(), fingerprint);
+    return found_it != fingerprints_.end();
+}
+
+FingerprintData FingerprintDatabase::parse_db_line(const std::string& line)
+{
+    FingerprintData result;
+
+    // legacy v1 certificate handling
+    if (std::count(line.begin(), line.end(), ':') == 19 && line.size() == 40 + 19) {
+        auto data = string::from_hex(line);
+        if (data.empty()) {
+            return result;
+        }
+        result.algorithm = fingerprint_type_to_string(FingerprintType::SHA1);
+        result.data = data;
+        return result;
+    }
+
+    auto version_end_pos = line.find(':');
+    if (version_end_pos == std::string::npos) {
+        return result;
+    }
+    if (line.substr(0, version_end_pos) != "v2") {
+        return result;
+    }
+    auto algo_start_pos = version_end_pos + 1;
+    auto algo_end_pos = line.find(':', algo_start_pos);
+    if (algo_end_pos == std::string::npos) {
+        return result;
+    }
+    auto algorithm = line.substr(algo_start_pos, algo_end_pos - algo_start_pos);
+    auto data = string::from_hex(line.substr(algo_end_pos + 1));
+
+    if (data.empty()) {
+        return result;
+    }
+
+    result.algorithm = algorithm;
+    result.data = data;
+    return result;
+}
+
+std::string FingerprintDatabase::to_db_line(const FingerprintData& fingerprint)
+{
+    return "v2:" + fingerprint.algorithm + ":" + string::to_hex(fingerprint.data, 2);
+}
+
+} // namespace barrier

src/lib/net/FingerprintDatabase.h

@@ -0,0 +1,61 @@
+/*
+    barrier -- mouse and keyboard sharing utility
+    Copyright (C) Barrier contributors
+
+    This package is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    found in the file LICENSE that should have accompanied this file.
+
+    This package is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef BARRIER_LIB_NET_FINGERPRINT_DATABASE_H
+#define BARRIER_LIB_NET_FINGERPRINT_DATABASE_H
+
+#include "FingerprintType.h"
+#include <iosfwd>
+#include <string>
+#include <vector>
+
+namespace barrier {
+
+struct FingerprintData {
+    std::string algorithm;
+    std::vector<std::uint8_t> data;
+
+    bool valid() const { return !algorithm.empty(); }
+
+    bool operator==(const FingerprintData& other) const;
+};
+
+class FingerprintDatabase {
+public:
+    void read(const std::string& path);
+    void write(const std::string& path);
+
+    void read_stream(std::istream& stream);
+    void write_stream(std::ostream& stream);
+
+    void clear();
+    void add_trusted(const FingerprintData& fingerprint);
+    bool is_trusted(const FingerprintData& fingerprint);
+
+    const std::vector<FingerprintData>& fingerprints() const { return fingerprints_; }
+
+    static FingerprintData parse_db_line(const std::string& line);
+    static std::string to_db_line(const FingerprintData& fingerprint);
+
+private:
+
+    std::vector<FingerprintData> fingerprints_;
+};
+
+} // namespace barrier
+
+#endif // BARRIER_LIB_NET_FINGERPRINT_DATABASE_H

src/lib/net/FingerprintType.h

@@ -0,0 +1,54 @@
+/*
+    barrier -- mouse and keyboard sharing utility
+    Copyright (C) Barrier contributors
+
+    This package is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    found in the file LICENSE that should have accompanied this file.
+
+    This package is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef BARRIER_LIB_NET_FINGERPRINT_TYPE_H
+#define BARRIER_LIB_NET_FINGERPRINT_TYPE_H
+
+#include <string>
+
+namespace barrier {
+
+enum FingerprintType {
+    INVALID,
+    SHA1, // deprecated
+    SHA256,
+};
+
+inline const char* fingerprint_type_to_string(FingerprintType type)
+{
+    switch (type) {
+        case FingerprintType::INVALID: return "invalid";
+        case FingerprintType::SHA1: return "sha1";
+        case FingerprintType::SHA256: return "sha256";
+    }
+    return "invalid";
+}
+
+inline FingerprintType fingerprint_type_from_string(const std::string& type)
+{
+    if (type == "sha1") {
+        return FingerprintType::SHA1;
+    }
+    if (type == "sha256") {
+        return FingerprintType::SHA256;
+    }
+    return FingerprintType::INVALID;
+}
+
+} // namespace barrier
+
+#endif // BARRIER_LIB_NET_FINGERPRINT_TYPE_H

src/lib/net/SecureUtils.h

@@ -18,6 +18,7 @@
 #ifndef BARRIER_LIB_NET_SECUREUTILS_H
 #define BARRIER_LIB_NET_SECUREUTILS_H
 
+#include "FingerprintType.h"
 #include <openssl/ossl_typ.h>
 #include <cstdint>
 #include <string>
@@ -25,11 +26,6 @@
 
 namespace barrier {
 
-enum FingerprintType {
-    SHA1, // deprecated
-    SHA256,
-};
-
 std::string format_ssl_fingerprint(const std::vector<std::uint8_t>& fingerprint,
                                    bool separator = true);
 

src/test/unittests/net/FingerprintDatabaseTests.cpp

@@ -0,0 +1,95 @@
+/*
+    barrier -- mouse and keyboard sharing utility
+    Copyright (C) Barrier contributors
+
+    This package is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    found in the file LICENSE that should have accompanied this file.
+
+    This package is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "net/FingerprintDatabase.h"
+#include "test/global/gtest.h"
+
+namespace barrier {
+
+TEST(FingerprintDatabase, parse_db_line)
+{
+    ASSERT_FALSE(FingerprintDatabase::parse_db_line("").valid());
+    ASSERT_FALSE(FingerprintDatabase::parse_db_line("abcd").valid());
+    ASSERT_FALSE(FingerprintDatabase::parse_db_line("v1:algo:something").valid());
+    ASSERT_FALSE(FingerprintDatabase::parse_db_line("v2:algo:something").valid());
+    ASSERT_FALSE(FingerprintDatabase::parse_db_line("v2:algo:01020304abc").valid());
+    ASSERT_FALSE(FingerprintDatabase::parse_db_line("v2:algo:01020304ZZ").valid());
+    ASSERT_EQ(FingerprintDatabase::parse_db_line("v2:algo:01020304ab"),
+              (FingerprintData{"algo", {1, 2, 3, 4, 0xab}}));
+}
+
+TEST(FingerprintDatabase, read)
+{
+    std::istringstream stream;
+    stream.str(R"(
+v2:algo1:01020304ab
+v2:algo2:03040506ab
+AB:CD:EF:00:01:02:03:04:05:06:07:08:09:10:11:12:13:14:15:16
+)");
+    FingerprintDatabase db;
+    db.read_stream(stream);
+
+    std::vector<FingerprintData> expected = {
+        { "algo1", { 1, 2, 3, 4, 0xab } },
+        { "algo2", { 3, 4, 5, 6, 0xab } },
+        { "sha1", { 0xab, 0xcd, 0xef, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
+                    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16 } },
+    };
+    ASSERT_EQ(db.fingerprints(), expected);
+}
+
+TEST(FingerprintDatabase, write)
+{
+    std::ostringstream stream;
+
+    FingerprintDatabase db;
+    db.add_trusted({ "algo1", { 1, 2, 3, 4, 0xab } });
+    db.add_trusted({ "algo2", { 3, 4, 5, 6, 0xab } });
+    db.write_stream(stream);
+
+    ASSERT_EQ(stream.str(), R"(v2:algo1:01020304ab
+v2:algo2:03040506ab
+)");
+}
+
+TEST(FingerprintDatabase, clear)
+{
+    FingerprintDatabase db;
+    db.add_trusted({ "algo1", { 1, 2, 3, 4, 0xab } });
+    db.clear();
+    ASSERT_TRUE(db.fingerprints().empty());
+}
+
+TEST(FingerprintDatabase, add_trusted_no_duplicates)
+{
+    FingerprintDatabase db;
+    db.add_trusted({ "algo1", { 1, 2, 3, 4, 0xab } });
+    db.add_trusted({ "algo2", { 3, 4, 5, 6, 0xab } });
+    db.add_trusted({ "algo1", { 1, 2, 3, 4, 0xab } });
+    ASSERT_EQ(db.fingerprints().size(), 2);
+}
+
+TEST(FingerprintDatabase, is_trusted)
+{
+    FingerprintDatabase db;
+    db.add_trusted({ "algo1", { 1, 2, 3, 4, 0xab } });
+    ASSERT_TRUE(db.is_trusted({ "algo1", { 1, 2, 3, 4, 0xab } }));
+    ASSERT_FALSE(db.is_trusted({ "algo2", { 1, 2, 3, 4, 0xab } }));
+    ASSERT_FALSE(db.is_trusted({ "algo1", { 1, 2, 3, 4, 0xac } }));
+}
+
+} // namespace barrier