source/lib/secure_crt.h

   1 /* Copyright (C) 2015 Wildfire Games.
   2  *
   3  * Permission is hereby granted, free of charge, to any person obtaining
   4  * a copy of this software and associated documentation files (the
   5  * "Software"), to deal in the Software without restriction, including
   6  * without limitation the rights to use, copy, modify, merge, publish,
   7  * distribute, sublicense, and/or sell copies of the Software, and to
   8  * permit persons to whom the Software is furnished to do so, subject to
   9  * the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included
  12  * in all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  17  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
  18  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  19  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  20  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21  */
  22
  23 /*
  24  * partial implementation of VC8's secure CRT functions
  25  */
  26
  27 #ifndef INCLUDED_SECURE_CRT
  28 #define INCLUDED_SECURE_CRT
  29
  30 #include <stdarg.h>
  31
  32 #include "lib/status.h"
  33
  34 namespace ERR
  35 {
  36         const Status STRING_NOT_TERMINATED = -100600;
  37 }
  38
  39 // if the platform lacks a secure CRT implementation, we'll provide one.
  40 #if MSC_VERSION
  41 # define EMULATE_SECURE_CRT 0
  42 #else
  43 # define EMULATE_SECURE_CRT 1
  44 #endif
  45
  46
  47 #if EMULATE_SECURE_CRT
  48
  49 // (conflicts with glibc definitions)
  50 #if !OS_UNIX || OS_MACOSX || OS_OPENBSD
  51 // return length [in characters] of a string, not including the trailing
  52 // null character. to protect against access violations, only the
  53 // first <max_len> characters are examined; if the null character is
  54 // not encountered by then, <max_len> is returned.
  55 // strnlen is available on OpenBSD and MacOS
  56 #if !OS_OPENBSD && !OS_MACOSX
  57 extern size_t strnlen(const char* str, size_t max_len);
  58 #endif
  59 extern size_t wcsnlen(const wchar_t* str, size_t max_len);
  60 #endif
  61
  62 // copy at most <max_src_chars> (not including trailing null) from
  63 // <src> into <dst>, which must not overlap.
  64 // if thereby <max_dst_chars> (including null) would be exceeded,
  65 // <dst> is set to the empty string and ERANGE returned; otherwise,
  66 // 0 is returned to indicate success and that <dst> is null-terminated.
  67 //
  68 // note: padding with zeroes is not called for by NG1031.
  69 extern int strncpy_s(char* dst, size_t max_dst_chars, const char* src, size_t max_src_chars);
  70 extern int wcsncpy_s(wchar_t* dst, size_t max_dst_chars, const wchar_t* src, size_t max_src_chars);
  71
  72 // copy <src> (including trailing null) into <dst>, which must not overlap.
  73 // if thereby <max_dst_chars> (including null) would be exceeded,
  74 // <dst> is set to the empty string and ERANGE returned; otherwise,
  75 // 0 is returned to indicate success and that <dst> is null-terminated.
  76 //
  77 // note: implemented as tncpy_s(dst, max_dst_chars, src, SIZE_MAX)
  78 extern int strcpy_s(char* dst, size_t max_dst_chars, const char* src);
  79 extern int wcscpy_s(wchar_t* dst, size_t max_dst_chars, const wchar_t* src);
  80
  81 // append at most <max_src_chars> (not including trailing null) from
  82 // <src> to <dst>, which must not overlap.
  83 // if thereby <max_dst_chars> (including null) would be exceeded,
  84 // <dst> is set to the empty string and ERANGE returned; otherwise,
  85 // 0 is returned to indicate success and that <dst> is null-terminated.
  86 extern int strncat_s(char* dst, size_t max_dst_chars, const char* src, size_t max_src_chars);
  87 extern int wcsncat_s(wchar_t* dst, size_t max_dst_chars, const wchar_t* src, size_t max_src_chars);
  88
  89 // append <src> to <dst>, which must not overlap.
  90 // if thereby <max_dst_chars> (including null) would be exceeded,
  91 // <dst> is set to the empty string and ERANGE returned; otherwise,
  92 // 0 is returned to indicate success and that <dst> is null-terminated.
  93 //
  94 // note: implemented as tncat_s(dst, max_dst_chars, src, SIZE_MAX)
  95 extern int strcat_s(char* dst, size_t max_dst_chars, const char* src);
  96 extern int wcscat_s(wchar_t* dst, size_t max_dst_chars, const wchar_t* src);
  97
  98 extern int vsprintf_s(char* dst, size_t max_dst_chars, const char* fmt, va_list ap) VPRINTF_ARGS(3);
  99 extern int vswprintf_s(wchar_t* dst, size_t max_dst_chars, const wchar_t* fmt, va_list ap) VWPRINTF_ARGS(3);
 100
 101 extern int sprintf_s(char* buf, size_t max_chars, const char* fmt, ...) PRINTF_ARGS(3);
 102 extern int swprintf_s(wchar_t* buf, size_t max_chars, const wchar_t* fmt, ...) WPRINTF_ARGS(3);
 103
 104 // we'd like to avoid deprecation warnings caused by scanf. selective
 105 // 'undeprecation' isn't possible, replacing all stdio declarations with
 106 // our own deprecation scheme is a lot of work, suppressing all deprecation
 107 // warnings would cause important other warnings to be missed, and avoiding
 108 // scanf outright isn't convenient.
 109 // the remaining alternative is using scanf_s where available and otherwise
 110 // defining it to scanf. note that scanf_s has a different API:
 111 // any %s or %c or %[ format specifier's buffer must be followed by a
 112 // size parameter. callers must either avoid these, or provide two codepaths
 113 // (use scanf #if EMULATE_SECURE_CRT, otherwise scanf_s).
 114 #define scanf_s scanf
 115 #define wscanf_s wscanf
 116 #define fscanf_s fscanf
 117 #define fwscanf_s fwscanf
 118 #define sscanf_s sscanf
 119 #define swscanf_s swscanf
 120
 121 #endif  // #if EMULATE_SECURE_CRT
 122 #endif  // #ifndef INCLUDED_SECURE_CRT