From 88646061e0729863116c9e2d7bfd461b47e450a4 Mon Sep 17 00:00:00 2001 From: Kieran Bingham Date: Fri, 22 Mar 2019 10:00:44 +0000 Subject: libcamera: utils: Use internal secure_getenv() implementation 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 1b2a62c0..79038a96 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 eb444c31..71cfbc42 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 fae28cee..cd0fd761 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. -- cgit v1.2.1