initial commit, 4.5 stable

thirdparty/mbedtls/include/mbedtls/platform_util.h

@@ -0,0 +1,247 @@
+/**
+ * \file platform_util.h
+ *
+ * \brief Common and shared functions used by multiple modules in the Mbed TLS
+ *        library.
+ */
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+#ifndef MBEDTLS_PLATFORM_UTIL_H
+#define MBEDTLS_PLATFORM_UTIL_H
+
+#include "mbedtls/build_info.h"
+
+#include <stddef.h>
+#if defined(MBEDTLS_HAVE_TIME_DATE)
+#include "mbedtls/platform_time.h"
+#include <time.h>
+#endif /* MBEDTLS_HAVE_TIME_DATE */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Internal helper macros for deprecating API constants. */
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+#define MBEDTLS_DEPRECATED __attribute__((deprecated))
+MBEDTLS_DEPRECATED typedef char const *mbedtls_deprecated_string_constant_t;
+#define MBEDTLS_DEPRECATED_STRING_CONSTANT(VAL)       \
+    ((mbedtls_deprecated_string_constant_t) (VAL))
+MBEDTLS_DEPRECATED typedef int mbedtls_deprecated_numeric_constant_t;
+#define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT(VAL)       \
+    ((mbedtls_deprecated_numeric_constant_t) (VAL))
+#else /* MBEDTLS_DEPRECATED_WARNING */
+#define MBEDTLS_DEPRECATED
+#define MBEDTLS_DEPRECATED_STRING_CONSTANT(VAL) VAL
+#define MBEDTLS_DEPRECATED_NUMERIC_CONSTANT(VAL) VAL
+#endif /* MBEDTLS_DEPRECATED_WARNING */
+#endif /* MBEDTLS_DEPRECATED_REMOVED */
+
+/* Implementation of the check-return facility.
+ * See the user documentation in mbedtls_config.h.
+ *
+ * Do not use this macro directly to annotate function: instead,
+ * use one of MBEDTLS_CHECK_RETURN_CRITICAL or MBEDTLS_CHECK_RETURN_TYPICAL
+ * depending on how important it is to check the return value.
+ */
+#if !defined(MBEDTLS_CHECK_RETURN)
+#if defined(__GNUC__)
+#define MBEDTLS_CHECK_RETURN __attribute__((__warn_unused_result__))
+#elif defined(_MSC_VER) && _MSC_VER >= 1700
+#include <sal.h>
+#define MBEDTLS_CHECK_RETURN _Check_return_
+#else
+#define MBEDTLS_CHECK_RETURN
+#endif
+#endif
+
+/** Critical-failure function
+ *
+ * This macro appearing at the beginning of the declaration of a function
+ * indicates that its return value should be checked in all applications.
+ * Omitting the check is very likely to indicate a bug in the application
+ * and will result in a compile-time warning if #MBEDTLS_CHECK_RETURN
+ * is implemented for the compiler in use.
+ *
+ * \note  The use of this macro is a work in progress.
+ *        This macro may be added to more functions in the future.
+ *        Such an extension is not considered an API break, provided that
+ *        there are near-unavoidable circumstances under which the function
+ *        can fail. For example, signature/MAC/AEAD verification functions,
+ *        and functions that require a random generator, are considered
+ *        return-check-critical.
+ */
+#define MBEDTLS_CHECK_RETURN_CRITICAL MBEDTLS_CHECK_RETURN
+
+/** Ordinary-failure function
+ *
+ * This macro appearing at the beginning of the declaration of a function
+ * indicates that its return value should be generally be checked in portable
+ * applications. Omitting the check will result in a compile-time warning if
+ * #MBEDTLS_CHECK_RETURN is implemented for the compiler in use and
+ * #MBEDTLS_CHECK_RETURN_WARNING is enabled in the compile-time configuration.
+ *
+ * You can use #MBEDTLS_IGNORE_RETURN to explicitly ignore the return value
+ * of a function that is annotated with #MBEDTLS_CHECK_RETURN.
+ *
+ * \note  The use of this macro is a work in progress.
+ *        This macro will be added to more functions in the future.
+ *        Eventually this should appear before most functions returning
+ *        an error code (as \c int in the \c mbedtls_xxx API or
+ *        as ::psa_status_t in the \c psa_xxx API).
+ */
+#if defined(MBEDTLS_CHECK_RETURN_WARNING)
+#define MBEDTLS_CHECK_RETURN_TYPICAL MBEDTLS_CHECK_RETURN
+#else
+#define MBEDTLS_CHECK_RETURN_TYPICAL
+#endif
+
+/** Benign-failure function
+ *
+ * This macro appearing at the beginning of the declaration of a function
+ * indicates that it is rarely useful to check its return value.
+ *
+ * This macro has an empty expansion. It exists for documentation purposes:
+ * a #MBEDTLS_CHECK_RETURN_OPTIONAL annotation indicates that the function
+ * has been analyzed for return-check usefulness, whereas the lack of
+ * an annotation indicates that the function has not been analyzed and its
+ * return-check usefulness is unknown.
+ */
+#define MBEDTLS_CHECK_RETURN_OPTIONAL
+
+/** \def MBEDTLS_IGNORE_RETURN
+ *
+ * Call this macro with one argument, a function call, to suppress a warning
+ * from #MBEDTLS_CHECK_RETURN due to that function call.
+ */
+#if !defined(MBEDTLS_IGNORE_RETURN)
+/* GCC doesn't silence the warning with just (void)(result).
+ * (void)!(result) is known to work up at least up to GCC 10, as well
+ * as with Clang and MSVC.
+ *
+ * https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Non_002dbugs.html
+ * https://stackoverflow.com/questions/40576003/ignoring-warning-wunused-result
+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66425#c34
+ */
+#define MBEDTLS_IGNORE_RETURN(result) ((void) !(result))
+#endif
+
+/* If the following macro is defined, the library is being built by the test
+ * framework, and the framework is going to provide a replacement
+ * mbedtls_platform_zeroize() using a preprocessor macro, so the function
+ * declaration should be omitted.  */
+#if !defined(MBEDTLS_TEST_DEFINES_ZEROIZE) //no-check-names
+/**
+ * \brief       Securely zeroize a buffer
+ *
+ *              The function is meant to wipe the data contained in a buffer so
+ *              that it can no longer be recovered even if the program memory
+ *              is later compromised. Call this function on sensitive data
+ *              stored on the stack before returning from a function, and on
+ *              sensitive data stored on the heap before freeing the heap
+ *              object.
+ *
+ *              It is extremely difficult to guarantee that calls to
+ *              mbedtls_platform_zeroize() are not removed by aggressive
+ *              compiler optimizations in a portable way. For this reason, Mbed
+ *              TLS provides the configuration option
+ *              MBEDTLS_PLATFORM_ZEROIZE_ALT, which allows users to configure
+ *              mbedtls_platform_zeroize() to use a suitable implementation for
+ *              their platform and needs
+ *
+ * \param buf   Buffer to be zeroized
+ * \param len   Length of the buffer in bytes
+ *
+ */
+void mbedtls_platform_zeroize(void *buf, size_t len);
+#endif
+
+/** \brief              The type of custom random generator (RNG) callbacks.
+ *
+ *                      Many Mbed TLS functions take two parameters
+ *                      `mbedtls_f_rng_t *f_rng, void *p_rng`. The
+ *                      library will call \c f_rng to generate
+ *                      random values.
+ *
+ * \note                This is typically one of the following:
+ *                      - mbedtls_ctr_drbg_random() with \c p_rng
+ *                        pointing to a #mbedtls_ctr_drbg_context;
+ *                      - mbedtls_hmac_drbg_random() with \c p_rng
+ *                        pointing to a #mbedtls_hmac_drbg_context;
+ *                      - mbedtls_psa_get_random() with
+ *                        `prng = MBEDTLS_PSA_RANDOM_STATE`.
+ *
+ * \note                Generally, given a call
+ *                      `mbedtls_foo(f_rng, p_rng, ....)`, the RNG callback
+ *                      and the context only need to remain valid until
+ *                      the call to `mbedtls_foo` returns. However, there
+ *                      are a few exceptions where the callback is stored
+ *                      in for future use. Check the documentation of
+ *                      the calling function.
+ *
+ * \warning             In a multithreaded environment, calling the
+ *                      function should be thread-safe. The standard
+ *                      functions provided by the library are thread-safe
+ *                      when #MBEDTLS_THREADING_C is enabled.
+ *
+ * \warning             This function must either provide as many
+ *                      bytes as requested of **cryptographic quality**
+ *                      random data, or return a negative error code.
+ *
+ * \param p_rng         The \c p_rng argument that was passed along \c f_rng.
+ *                      The library always passes \c p_rng unchanged.
+ *                      This is typically a pointer to the random generator
+ *                      state, or \c NULL if the custom random generator
+ *                      doesn't need a context-specific state.
+ * \param[out] output   On success, this must be filled with \p output_size
+ *                      bytes of cryptographic-quality random data.
+ * \param output_size   The number of bytes to output.
+ *
+ * \return              \c 0 on success, or a negative error code on failure.
+ *                      Library functions will generally propagate this
+ *                      error code, so \c MBEDTLS_ERR_xxx values are
+ *                      recommended. #MBEDTLS_ERR_ENTROPY_SOURCE_FAILED is
+ *                      typically sensible for RNG failures.
+ */
+typedef int mbedtls_f_rng_t(void *p_rng,
+                            unsigned char *output, size_t output_size);
+
+#if defined(MBEDTLS_HAVE_TIME_DATE)
+/**
+ * \brief      Platform-specific implementation of gmtime_r()
+ *
+ *             The function is a thread-safe abstraction that behaves
+ *             similarly to the gmtime_r() function from Unix/POSIX.
+ *
+ *             Mbed TLS will try to identify the underlying platform and
+ *             make use of an appropriate underlying implementation (e.g.
+ *             gmtime_r() for POSIX and gmtime_s() for Windows). If this is
+ *             not possible, then gmtime() will be used. In this case, calls
+ *             from the library to gmtime() will be guarded by the mutex
+ *             mbedtls_threading_gmtime_mutex if MBEDTLS_THREADING_C is
+ *             enabled. It is recommended that calls from outside the library
+ *             are also guarded by this mutex.
+ *
+ *             If MBEDTLS_PLATFORM_GMTIME_R_ALT is defined, then Mbed TLS will
+ *             unconditionally use the alternative implementation for
+ *             mbedtls_platform_gmtime_r() supplied by the user at compile time.
+ *
+ * \param tt     Pointer to an object containing time (in seconds) since the
+ *               epoch to be converted
+ * \param tm_buf Pointer to an object where the results will be stored
+ *
+ * \return      Pointer to an object of type struct tm on success, otherwise
+ *              NULL
+ */
+struct tm *mbedtls_platform_gmtime_r(const mbedtls_time_t *tt,
+                                     struct tm *tm_buf);
+#endif /* MBEDTLS_HAVE_TIME_DATE */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MBEDTLS_PLATFORM_UTIL_H */