Make gmtime() configurable at compile-time

This commit is contained in:
Andres Amaya Garcia 2018-08-16 21:42:09 +01:00
parent d7177435e3
commit 1abb368b87
6 changed files with 117 additions and 33 deletions

View file

@ -3091,6 +3091,25 @@
*/ */
//#define MBEDTLS_PLATFORM_ZEROIZE_ALT //#define MBEDTLS_PLATFORM_ZEROIZE_ALT
/**
* Uncomment the macro to let Mbed TLS use your alternate implementation of
* mbedtls_platform_gmtime(). This replaces the default implementation in
* platform_util.c.
*
* gmtime() is not a thread safe function as defined in the C standard. The
* library will try to use safer implementations of this function, such as
* gmtime_r() when available. However, if Mbed TLS cannot identify the target
* system, the implementation of mbedtls_platform_gmtime() will default to
* using the standard gmtime(). In this case, calls from the library to
* gmtime() will be guarded by the global mutex mbedtls_threading_gmtime_mutex
* if MBEDTLS_THREADING_C is enable. It is advised that calls from outside the
* library are also guarded with this mutex to avoid race conditions. However,
* if the macro MBEDTLS_PLATFORM_GMTIME_ALT is defined, Mbed TLS will
* unconditionally use the implementation for mbedtls_platform_time() supplied
* at compile time.
*/
//#define MBEDTLS_PLATFORM_GMTIME_ALT
/* \} name SECTION: Customisation configuration options */ /* \} name SECTION: Customisation configuration options */
/* Target and application specific configurations */ /* Target and application specific configurations */

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@ -25,7 +25,18 @@
#ifndef MBEDTLS_PLATFORM_UTIL_H #ifndef MBEDTLS_PLATFORM_UTIL_H
#define MBEDTLS_PLATFORM_UTIL_H #define MBEDTLS_PLATFORM_UTIL_H
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include "mbedtls/platform_time.h"
#include <stddef.h> #include <stddef.h>
#if defined(MBEDTLS_HAVE_TIME_DATE)
#include <time.h>
#endif /* MBEDTLS_HAVE_TIME_DATE */
#ifdef __cplusplus #ifdef __cplusplus
extern "C" { extern "C" {
@ -55,6 +66,38 @@ extern "C" {
*/ */
void mbedtls_platform_zeroize( void *buf, size_t len ); void mbedtls_platform_zeroize( void *buf, size_t len );
#if defined(MBEDTLS_HAVE_TIME_DATE)
/**
* \brief Thread safe implementation of gmtime()
*
* The function is an abstraction that when called behaves similar
* to the gmtime() function from the C standard, but is thread
* safe.
*
* Mbed TLS will try to identify the underlying platform and
* configure 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_ALT is defined, then Mbed TLS will
* unconditionally use the alternative implementation for
* mbedtls_platform_gmtime() supplied by the user at compile time
*
* \param tt Pointer to an object containing time (in seconds) since the
* Epoc to be converted
* \param tm 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( const mbedtls_time_t *tt,
struct tm *tm_buf );
#endif /* MBEDTLS_HAVE_TIME_DATE */
#ifdef __cplusplus #ifdef __cplusplus
} }
#endif #endif

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@ -103,9 +103,9 @@ extern mbedtls_threading_mutex_t mbedtls_threading_readdir_mutex;
#if !defined(_WIN32) && (defined(__unix__) || \ #if !defined(_WIN32) && (defined(__unix__) || \
(defined(__APPLE__) && defined(__MACH__))) (defined(__APPLE__) && defined(__MACH__)))
#include <unistd.h> #include <unistd.h>
#if !defined(_POSIX_VERSION) #if !defined(_POSIX_VERSION) || 200112L > _POSIX_THREAD_SAFE_FUNCTIONS
extern mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex; extern mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex;
#endif /* !_POSIX_VERSION */ #endif /* !_POSIX_VERSION || 200112L > _POSIX_THREAD_SAFE_FUNCTIONS */
#endif /* !_WIN32 && (__unix__ || (__APPLE__ && __MACH__)) */ #endif /* !_WIN32 && (__unix__ || (__APPLE__ && __MACH__)) */
#endif /* MBEDTLS_HAVE_TIME_DATE */ #endif /* MBEDTLS_HAVE_TIME_DATE */
#endif /* MBEDTLS_THREADING_C */ #endif /* MBEDTLS_THREADING_C */

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@ -20,6 +20,12 @@
* This file is part of Mbed TLS (https://tls.mbed.org) * This file is part of Mbed TLS (https://tls.mbed.org)
*/ */
/*
* Ensure gmtime_r is available even with -std=c99; must be included before
* config.h, which pulls in glibc's features.h. Harmless on other platforms.
*/
#define _POSIX_C_SOURCE 200112L
#if !defined(MBEDTLS_CONFIG_FILE) #if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h" #include "mbedtls/config.h"
#else #else
@ -27,6 +33,7 @@
#endif #endif
#include "mbedtls/platform_util.h" #include "mbedtls/platform_util.h"
#include "mbedtls/threading.h"
#include <stddef.h> #include <stddef.h>
#include <string.h> #include <string.h>
@ -65,3 +72,45 @@ void mbedtls_platform_zeroize( void *buf, size_t len )
memset_func( buf, 0, len ); memset_func( buf, 0, len );
} }
#endif /* MBEDTLS_PLATFORM_ZEROIZE_ALT */ #endif /* MBEDTLS_PLATFORM_ZEROIZE_ALT */
#if defined(MBEDTLS_HAVE_TIME_DATE) && !defined(MBEDTLS_PLATFORM_GMTIME_ALT)
#include <time.h>
#if !defined(_WIN32) && (defined(__unix__) || \
(defined(__APPLE__) && defined(__MACH__)))
#include <unistd.h>
#if !defined(_POSIX_VERSION) || _POSIX_C_SOURCE > _POSIX_THREAD_SAFE_FUNCTIONS
#define PLATFORM_UTIL_USE_GMTIME
#endif /* !_POSIX_VERSION || _POSIX_C_SOURCE > _POSIX_THREAD_SAFE_FUNCTIONS */
#endif /* !_WIN32 && (__unix__ || (__APPLE__ && __MACH__)) */
struct tm *mbedtls_platform_gmtime( const mbedtls_time_t *tt,
struct tm *tm_buf )
{
#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
return ( gmtime_s( tm_buf, tt ) == 0 ) ? tm_buf : NULL;
#elif !defined(PLATFORM_UTIL_USE_GMTIME)
return gmtime_r( tt, tm_buf );
#else
struct tm *lt;
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_lock( &mbedtls_threading_gmtime_mutex ) != 0 )
return( NULL );
#endif /* MBEDTLS_THREADING_C */
lt = gmtime( tt );
if( lt != NULL )
{
memcpy( tm_buf, lt, sizeof( struct tm ) );
}
#if defined(MBEDTLS_THREADING_C)
if( mbedtls_mutex_unlock( &mbedtls_threading_gmtime_mutex ) != 0 )
return( NULL );
#endif /* MBEDTLS_THREADING_C */
return ( lt == NULL ) ? NULL : tm_buf;
#endif
}
#endif /* MBEDTLS_HAVE_TIME_DATE && MBEDTLS_PLATFORM_GMTIME_ALT */

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@ -32,9 +32,9 @@
#if !defined(_WIN32) && (defined(__unix__) || \ #if !defined(_WIN32) && (defined(__unix__) || \
(defined(__APPLE__) && defined(__MACH__))) (defined(__APPLE__) && defined(__MACH__)))
#include <unistd.h> #include <unistd.h>
#if !defined(_POSIX_VERSION) #if !defined(_POSIX_VERSION) || 200112L > _POSIX_THREAD_SAFE_FUNCTIONS
#define THREADING_USE_GMTIME #define THREADING_USE_GMTIME
#endif /* !_POSIX_VERSION */ #endif /* !_POSIX_VERSION || 200112L > _POSIX_THREAD_SAFE_FUNCTIONS */
#endif /* !_WIN32 && (__unix__ || (__APPLE__ && __MACH__)) */ #endif /* !_WIN32 && (__unix__ || (__APPLE__ && __MACH__)) */
#if defined(MBEDTLS_THREADING_PTHREAD) #if defined(MBEDTLS_THREADING_PTHREAD)

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@ -29,10 +29,6 @@
* http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf * http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf
*/ */
/* Ensure gmtime_r is available even with -std=c99; must be included before
* config.h, which pulls in glibc's features.h. Harmless on other platforms. */
#define _POSIX_C_SOURCE 200112L
#if !defined(MBEDTLS_CONFIG_FILE) #if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h" #include "mbedtls/config.h"
#else #else
@ -67,6 +63,7 @@
#include "mbedtls/platform_time.h" #include "mbedtls/platform_time.h"
#endif #endif
#if defined(MBEDTLS_HAVE_TIME_DATE) #if defined(MBEDTLS_HAVE_TIME_DATE)
#include "mbedtls/platform_util.h"
#include <time.h> #include <time.h>
#endif #endif
@ -890,14 +887,6 @@ int mbedtls_x509_key_size_helper( char *buf, size_t buf_size, const char *name )
} }
#if defined(MBEDTLS_HAVE_TIME_DATE) #if defined(MBEDTLS_HAVE_TIME_DATE)
#if !defined(_WIN32) && (defined(__unix__) || \
(defined(__APPLE__) && defined(__MACH__)))
#include <unistd.h>
#if !defined(_POSIX_VERSION)
#define X509_USE_GMTIME
#endif /* !_POSIX_VERSION */
#endif /* !_WIN32 && (__unix__ || (__APPLE__ && __MACH__)) */
/* /*
* Set the time structure to the current time. * Set the time structure to the current time.
* Return 0 on success, non-zero on failure. * Return 0 on success, non-zero on failure.
@ -910,19 +899,8 @@ static int x509_get_current_time( mbedtls_x509_time *now )
(void)tm_buf; (void)tm_buf;
#if defined(MBEDTLS_THREADING_C) && defined(X509_USE_GMTIME)
if( mbedtls_mutex_lock( &mbedtls_threading_gmtime_mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
#endif /* MBEDTLS_THREADING_C && X509_USE_GMTIME */
tt = mbedtls_time( NULL ); tt = mbedtls_time( NULL );
#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) lt = mbedtls_platform_gmtime( &tt, &tm_buf );
lt = gmtime_s( &tm_buf, &tt ) == 0 ? &tm_buf : NULL;
#elif defined(_POSIX_VERSION)
lt = gmtime_r( &tt, &tm_buf );
#else
lt = gmtime( &tt );
#endif
if( lt == NULL ) if( lt == NULL )
ret = -1; ret = -1;
@ -936,11 +914,6 @@ static int x509_get_current_time( mbedtls_x509_time *now )
now->sec = lt->tm_sec; now->sec = lt->tm_sec;
} }
#if defined(MBEDTLS_THREADING_C) && defined(X509_USE_GMTIME)
if( mbedtls_mutex_unlock( &mbedtls_threading_gmtime_mutex ) != 0 )
return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
#endif /* MBEDTLS_THREADING_C && X509_USE_GMTIME */
return( ret ); return( ret );
} }