From patchwork Sat Feb 22 20:17:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "brian m. carlson" X-Patchwork-Id: 11398331 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 85CC1159A for ; Sat, 22 Feb 2020 20:18:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 65AF92071E for ; Sat, 22 Feb 2020 20:18:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (3072-bit key) header.d=crustytoothpaste.net header.i=@crustytoothpaste.net header.b="ytKuUvir" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727128AbgBVUST (ORCPT ); Sat, 22 Feb 2020 15:18:19 -0500 Received: from injection.crustytoothpaste.net ([192.241.140.119]:39084 "EHLO injection.crustytoothpaste.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726845AbgBVUSK (ORCPT ); Sat, 22 Feb 2020 15:18:10 -0500 Received: from camp.crustytoothpaste.net (unknown [IPv6:2001:470:b978:101:b610:a2f0:36c1:12e3]) (using TLSv1.2 with cipher ECDHE-RSA-CHACHA20-POLY1305 (256/256 bits)) (No client certificate requested) by injection.crustytoothpaste.net (Postfix) with ESMTPSA id A6035609CF for ; Sat, 22 Feb 2020 20:18:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=crustytoothpaste.net; s=default; t=1582402688; bh=6uio+d3QXWKXcMv9s2bfm8cDR0vB66lxcbecR11CQoY=; h=From:To:Subject:Date:In-Reply-To:References:From:Reply-To:Subject: Date:To:CC:Resent-Date:Resent-From:Resent-To:Resent-Cc:In-Reply-To: References:Content-Type:Content-Disposition; b=ytKuUvirJzaFUH4b7xrO7YBzLdih+eTb+pH6iFHHLwkMB0DUrYfExZ33Bb4Uew2S4 NMoDrLoUCRGIPaVel7QeyqlLL/ZkNjsOCMMYPCrimrJjXMNp7eqLVDweQNUnMewYHb z0g1iIQBfulXw6V8QcQAng6a+EWTAOLwTG79eYh40LSE8In6zr47sZIbPu9ocDnlJZ svHpxzSHqjcjLp19UWxCTUbRdens4wlJP8KSMnml+jz7YNA0IYDvtPymWsLTzkKZ+s yrABSlJ4PN7ETxkhqve/EXm7xFqIyZdx5AM5z6hEgQzHrmH/D83Z7UjrPKc3yTtz1F xN/lzCulZjdpSBfLYex6Xkbcda23zrZIFauGBUCm7cYpaAUmA3uu0OUdGyGSu8Bbgz h1H0ijV0YmN8RfN59yfoRxnH7VzS2s2GefqBUZ+2clYIq34N4QO3j4Nl/Ku966VnjM hJN59e/mFyA458UQVKTKp32yeqEmOVOruFWcvakE6qnHsB2ThU6 From: "brian m. carlson" To: Subject: [PATCH v2 13/24] builtin/init-db: allow specifying hash algorithm on command line Date: Sat, 22 Feb 2020 20:17:38 +0000 Message-Id: <20200222201749.937983-14-sandals@crustytoothpaste.net> X-Mailer: git-send-email 2.25.1.481.gfbce0eb801 In-Reply-To: <20200222201749.937983-1-sandals@crustytoothpaste.net> References: <20200222201749.937983-1-sandals@crustytoothpaste.net> MIME-Version: 1.0 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Allow the user to specify the hash algorithm on the command line by using the --object-format option to git init. Validate that the user is not attempting to reinitialize a repository with a different hash algorithm. Ensure that if we are writing a non-SHA-1 repository that we set the repository version to 1 and write the objectFormat extension. Restrict this option to work only when ENABLE_SHA256 is set until the codebase is in a situation to fully support this. Signed-off-by: brian m. carlson --- Documentation/git-init.txt | 7 ++++- builtin/clone.c | 2 +- builtin/init-db.c | 52 +++++++++++++++++++++++++++++++++----- cache.h | 3 ++- 4 files changed, 55 insertions(+), 9 deletions(-) diff --git a/Documentation/git-init.txt b/Documentation/git-init.txt index 32880aafb0..adc6adfd38 100644 --- a/Documentation/git-init.txt +++ b/Documentation/git-init.txt @@ -10,7 +10,7 @@ SYNOPSIS -------- [verse] 'git init' [-q | --quiet] [--bare] [--template=] - [--separate-git-dir ] + [--separate-git-dir ] [--object-format=]] [directory] @@ -48,6 +48,11 @@ Only print error and warning messages; all other output will be suppressed. Create a bare repository. If `GIT_DIR` environment is not set, it is set to the current working directory. +--object-format=:: + +Specify the given object format (hash algorithm) for the repository. The valid +values are 'sha1' and (if enabled) 'sha256'. 'sha1' is the default. + --template=:: Specify the directory from which templates will be used. (See the "TEMPLATE diff --git a/builtin/clone.c b/builtin/clone.c index 4f6150c55c..961996a110 100644 --- a/builtin/clone.c +++ b/builtin/clone.c @@ -1097,7 +1097,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix) } } - init_db(git_dir, real_git_dir, option_template, INIT_DB_QUIET); + init_db(git_dir, real_git_dir, option_template, GIT_HASH_UNKNOWN, INIT_DB_QUIET); if (real_git_dir) git_dir = real_git_dir; diff --git a/builtin/init-db.c b/builtin/init-db.c index b11f07064d..d05552f0ae 100644 --- a/builtin/init-db.c +++ b/builtin/init-db.c @@ -177,7 +177,8 @@ static int needs_work_tree_config(const char *git_dir, const char *work_tree) } static int create_default_files(const char *template_path, - const char *original_git_dir) + const char *original_git_dir, + const struct repository_format *fmt) { struct stat st1; struct strbuf buf = STRBUF_INIT; @@ -187,6 +188,7 @@ static int create_default_files(const char *template_path, int reinit; int filemode; struct strbuf err = STRBUF_INIT; + int repo_version = GIT_REPO_VERSION; /* Just look for `init.templatedir` */ init_db_template_dir = NULL; /* re-set in case it was set before */ @@ -244,11 +246,23 @@ static int create_default_files(const char *template_path, exit(1); } +#ifndef ENABLE_SHA256 + if (fmt->hash_algo != GIT_HASH_SHA1) + die(_("The hash algorithm %s is not supported in this build."), hash_algos[fmt->hash_algo].name); +#endif + + if (fmt->hash_algo != GIT_HASH_SHA1) + repo_version = GIT_REPO_VERSION_READ; + /* This forces creation of new config file */ xsnprintf(repo_version_string, sizeof(repo_version_string), - "%d", GIT_REPO_VERSION); + "%d", repo_version); git_config_set("core.repositoryformatversion", repo_version_string); + if (fmt->hash_algo != GIT_HASH_SHA1) + git_config_set("extensions.objectformat", + hash_algos[fmt->hash_algo].name); + /* Check filemode trustability */ path = git_path_buf(&buf, "config"); filemode = TEST_FILEMODE; @@ -340,12 +354,26 @@ static void separate_git_dir(const char *git_dir, const char *git_link) write_file(git_link, "gitdir: %s", git_dir); } +static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash) +{ + /* + * If we already have an initialized repo, don't allow the user to + * specify a different algorithm, as that could cause corruption. + * Otherwise, if the user has specified one on the command line, use it. + */ + if (repo_fmt->version >= 0 && hash != GIT_HASH_UNKNOWN && hash != repo_fmt->hash_algo) + die(_("attempt to reinitialize repository with different hash")); + else if (hash != GIT_HASH_UNKNOWN) + repo_fmt->hash_algo = hash; +} + int init_db(const char *git_dir, const char *real_git_dir, - const char *template_dir, unsigned int flags) + const char *template_dir, int hash, unsigned int flags) { int reinit; int exist_ok = flags & INIT_DB_EXIST_OK; char *original_git_dir = real_pathdup(git_dir, 1); + struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT; if (real_git_dir) { struct stat st; @@ -378,9 +406,11 @@ int init_db(const char *git_dir, const char *real_git_dir, * config file, so this will not fail. What we are catching * is an attempt to reinitialize new repository with an old tool. */ - check_repository_format(NULL); + check_repository_format(&repo_fmt); - reinit = create_default_files(template_dir, original_git_dir); + validate_hash_algorithm(&repo_fmt, hash); + + reinit = create_default_files(template_dir, original_git_dir, &repo_fmt); create_object_directory(); @@ -482,6 +512,8 @@ int cmd_init_db(int argc, const char **argv, const char *prefix) const char *work_tree; const char *template_dir = NULL; unsigned int flags = 0; + const char *object_format = NULL; + int hash_algo = GIT_HASH_UNKNOWN; const struct option init_db_options[] = { OPT_STRING(0, "template", &template_dir, N_("template-directory"), N_("directory from which templates will be used")), @@ -494,6 +526,8 @@ int cmd_init_db(int argc, const char **argv, const char *prefix) OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET), OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"), N_("separate git dir from working tree")), + OPT_STRING(0, "object-format", &object_format, N_("hash"), + N_("specify the hash algorithm to use")), OPT_END() }; @@ -546,6 +580,12 @@ int cmd_init_db(int argc, const char **argv, const char *prefix) free(cwd); } + if (object_format) { + hash_algo = hash_algo_by_name(object_format); + if (hash_algo == GIT_HASH_UNKNOWN) + die(_("unknown hash algorithm '%s'"), object_format); + } + if (init_shared_repository != -1) set_shared_repository(init_shared_repository); @@ -597,5 +637,5 @@ int cmd_init_db(int argc, const char **argv, const char *prefix) UNLEAK(work_tree); flags |= INIT_DB_EXIST_OK; - return init_db(git_dir, real_git_dir, template_dir, flags); + return init_db(git_dir, real_git_dir, template_dir, hash_algo, flags); } diff --git a/cache.h b/cache.h index 29ee02a8d4..7a47e023ba 100644 --- a/cache.h +++ b/cache.h @@ -627,7 +627,8 @@ int path_inside_repo(const char *prefix, const char *path); #define INIT_DB_EXIST_OK 0x0002 int init_db(const char *git_dir, const char *real_git_dir, - const char *template_dir, unsigned int flags); + const char *template_dir, int hash_algo, + unsigned int flags); void sanitize_stdfds(void); int daemonize(void);