Userland: Add {md5,sha1,sha256,sha512}sum

Author: https://github.com/linusg
Commit: https://github.com/SerenityOS/serenity/commit/e9562e1920b
Pull-request: https://github.com/SerenityOS/serenity/pull/3468
Reviewed-by: https://github.com/alimpfard

Meta/build-root-filesystem.sh

@@ -151,6 +151,13 @@ ln -s Shell mnt/bin/sh
 ln -s test mnt/bin/[
 echo "done"
 
+printf "installing 'checksum' variants... "
+ln -s checksum mnt/bin/md5sum
+ln -s checksum mnt/bin/sha1sum
+ln -s checksum mnt/bin/sha256sum
+ln -s checksum mnt/bin/sha512sum
+echo "done"
+
 # Run local sync script, if it exists
 if [ -f sync-local.sh ]; then
     sh sync-local.sh

Userland/CMakeLists.txt

@@ -17,6 +17,7 @@ endforeach()
 
 target_link_libraries(aplay LibAudio)
 target_link_libraries(avol LibAudio)
+target_link_libraries(checksum LibCrypto)
 target_link_libraries(copy LibGUI)
 target_link_libraries(disasm LibX86)
 target_link_libraries(functrace LibDebug LibX86)

Userland/checksum.cpp

@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2020, Linus Groh <mail@linusgroh.de>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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 <LibCore/ArgsParser.h>
+#include <LibCore/File.h>
+#include <LibCrypto/Hash/HashManager.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int main(int argc, char** argv)
+{
+    if (pledge("stdio rpath", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    auto program_name = StringView { argv[0] };
+    auto hash_kind { Crypto::Hash::HashKind::None };
+
+    if (program_name == "md5sum")
+        hash_kind = Crypto::Hash::HashKind::MD5;
+    else if (program_name == "sha1sum")
+        hash_kind = Crypto::Hash::HashKind::SHA1;
+    else if (program_name == "sha256sum")
+        hash_kind = Crypto::Hash::HashKind::SHA256;
+    else if (program_name == "sha512sum")
+        hash_kind = Crypto::Hash::HashKind::SHA512;
+
+    if (hash_kind == Crypto::Hash::HashKind::None) {
+        fprintf(stderr, "Error: program must be executed as 'md5sum', 'sha1sum', 'sha256sum' or 'sha512sum'; got '%s'\n", argv[0]);
+        exit(1);
+    }
+
+    auto hash_name = program_name.substring_view(0, program_name.length() - 3).to_string().to_uppercase();
+    auto paths_help_string = String::format("File(s) to print %s checksum of", hash_name.characters());
+
+    Vector<const char*> paths;
+
+    Core::ArgsParser args_parser;
+    args_parser.add_positional_argument(paths, paths_help_string.characters(), "path", Core::ArgsParser::Required::No);
+    args_parser.parse(argc, argv);
+
+    if (paths.is_empty())
+        paths.append("-");
+
+    Crypto::Hash::Manager hash;
+    hash.initialize(hash_kind);
+
+    bool success;
+    auto has_error = false;
+    auto file = Core::File::construct();
+
+    for (auto path : paths) {
+        if (StringView { path } == "-") {
+            success = file->open(STDIN_FILENO, Core::IODevice::OpenMode::ReadOnly, Core::File::ShouldCloseFileDescription::No);
+        } else {
+            file->set_filename(path);
+            success = file->open(Core::IODevice::OpenMode::ReadOnly);
+        }
+        if (!success) {
+            fprintf(stderr, "%s: %s: %s\n", argv[0], path, file->error_string());
+            has_error = true;
+            continue;
+        }
+        hash.update(file->read_all());
+        auto digest = hash.digest();
+        auto digest_data = digest.immutable_data();
+        StringBuilder builder;
+        for (size_t i = 0; i < hash.digest_size(); ++i)
+            builder.appendf("%02x", digest_data[i]);
+        auto hash_sum_hex = builder.build();
+        printf("%s  %s\n", hash_sum_hex.characters(), path);
+    }
+    return has_error ? 1 : 0;
+}