From patchwork Wed Apr 3 04:10:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kieran Bingham X-Patchwork-Id: 885 Return-Path: Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id C609B610BF for ; Wed, 3 Apr 2019 06:11:17 +0200 (CEST) Received: from Q.imgcgcw.net (unknown [147.50.13.10]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 00F822F9; Wed, 3 Apr 2019 06:11:15 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1554264677; bh=+rnmzBA+pt89KB6IdNF1/OXYQQcy4jXoIQSW3hqa31Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bGxf1yzMM/Cu87fV/oRyPHX1EgZuXibc7h7klN4rU5LRmdKiO5nZfyNYlCPapHap4 bHqvLbAYZzvNs8Ry2KewbwE4cdKgApWByRlUM4febUAl/WRBoebx5ddgst7XxaCZJj kw1+G4o8mMHxNqFpS0Upxkw17arZbhM+hrWRG5mU= From: Kieran Bingham To: LibCamera Devel Date: Wed, 3 Apr 2019 11:10:58 +0700 Message-Id: <20190403041058.20921-5-kieran.bingham@ideasonboard.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190403041058.20921-1-kieran.bingham@ideasonboard.com> References: <20190403041058.20921-1-kieran.bingham@ideasonboard.com> MIME-Version: 1.0 Subject: [libcamera-devel] [PATCH v3 4/4] libcamera: utils: Use internal secure_getenv() implementation X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 Apr 2019 04:11:18 -0000 The secure_getenv() call is not provided by all C libraries. Support this feature by implementing our own version. Reviewed-by: Laurent Pinchart Signed-off-by: Kieran Bingham --- src/libcamera/include/utils.h | 2 ++ src/libcamera/log.cpp | 4 ++-- src/libcamera/utils.cpp | 22 ++++++++++++++++++++++ 3 files changed, 26 insertions(+), 2 deletions(-) diff --git a/src/libcamera/include/utils.h b/src/libcamera/include/utils.h index 1b2a62c0fda7..79038a96feab 100644 --- a/src/libcamera/include/utils.h +++ b/src/libcamera/include/utils.h @@ -24,6 +24,8 @@ std::unique_ptr make_unique(Args&&... args) return std::unique_ptr(new T(std::forward(args)...)); } +char *secure_getenv(const char *name); + } /* namespace utils */ } /* namespace libcamera */ diff --git a/src/libcamera/log.cpp b/src/libcamera/log.cpp index eb444c31857d..71cfbc422ba0 100644 --- a/src/libcamera/log.cpp +++ b/src/libcamera/log.cpp @@ -122,7 +122,7 @@ Logger::Logger() */ void Logger::parseLogFile() { - const char *file = secure_getenv("LIBCAMERA_LOG_FILE"); + const char *file = utils::secure_getenv("LIBCAMERA_LOG_FILE"); if (!file) return; @@ -140,7 +140,7 @@ void Logger::parseLogFile() */ void Logger::parseLogLevels() { - const char *debug = secure_getenv("LIBCAMERA_LOG_LEVELS"); + const char *debug = utils::secure_getenv("LIBCAMERA_LOG_LEVELS"); if (!debug) return; diff --git a/src/libcamera/utils.cpp b/src/libcamera/utils.cpp index fae28cee556a..cd0fd7614cc7 100644 --- a/src/libcamera/utils.cpp +++ b/src/libcamera/utils.cpp @@ -41,6 +41,28 @@ const char *basename(const char *path) return base ? base + 1 : path; } +/** + * \brief Get an environment variable + * \param[in] name The name of the variable to return + * + * The environment list is searched to find the variable 'name', and the + * corresponding string is returned. + * + * If 'secure execution' is required then this function always returns NULL to + * avoid vulnerabilities that could occur if set-user-ID or set-group-ID + * programs accidentally trust the environment. + * + * \returns A pointer to the value in the environment or NULL if the requested + * environment variable doesn't exist or if secure execution is required. + */ +char *secure_getenv(const char *name) +{ + if (getauxval(AT_SECURE)) + return NULL; + + return getenv(name); +} + /** * \fn libcamera::utils::make_unique(Args &&... args) * \brief Constructs an object of type T and wraps it in a std::unique_ptr.