src/libstrongswan/utils/integrity_checker.h

   1 /*
   2  * Copyright (C) 2009 Martin Willi
   3  * Hochschule fuer Technik Rapperswil
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  */
  15
  16 /**
  17  * @defgroup integrity_checker integrity_checker
  18  * @{ @ingroup utils
  19  */
  20
  21 #ifndef INTEGRITY_CHECKER_H_
  22 #define INTEGRITY_CHECKER_H_
  23
  24 #include "utils.h"
  25
  26 typedef struct integrity_checker_t integrity_checker_t;
  27 typedef struct integrity_checksum_t integrity_checksum_t;
  28
  29 /**
  30  * Struct to hold a precalculated checksum, implemented in the checksum library.
  31  */
  32 struct integrity_checksum_t {
  33         /* name of the checksum */
  34         char *name;
  35         /* size in bytes of the file on disk */
  36         size_t file_len;
  37         /* checksum of the file on disk */
  38         u_int32_t file;
  39         /* size in bytes of executable segment in memory */
  40         size_t segment_len;
  41         /* checksum of the executable segment in memory */
  42         u_int32_t segment;
  43 };
  44
  45 /**
  46  * Code integrity checker to detect non-malicious file manipulation.
  47  *
  48  * The integrity checker reads the checksums from a separate library
  49  * libchecksum.so to compare the checksums.
  50  */
  51 struct integrity_checker_t {
  52
  53         /**
  54          * Check the integrity of a file on disk.
  55          *
  56          * @param name          name to lookup checksum
  57          * @param file          path to file
  58          * @return                      TRUE if integrity tested successfully
  59          */
  60         bool (*check_file)(integrity_checker_t *this, char *name, char *file);
  61
  62         /**
  63          * Build the integrity checksum of a file on disk.
  64          *
  65          * @param file          path to file
  66          * @param len           return length in bytes of file
  67          * @return                      checksum, 0 on error
  68          */
  69         u_int32_t (*build_file)(integrity_checker_t *this, char *file, size_t *len);
  70
  71         /**
  72          * Check the integrity of the code segment in memory.
  73          *
  74          * @param name          name to lookup checksum
  75          * @param sym           a symbol in the segment to check
  76          * @return                      TRUE if integrity tested successfully
  77          */
  78         bool (*check_segment)(integrity_checker_t *this, char *name, void *sym);
  79         /**
  80          * Build the integrity checksum of a code segment in memory.
  81          *
  82          * @param sym           a symbol in the segment to check
  83          * @param len           return length in bytes of code segment in memory
  84          * @return                      checksum, 0 on error
  85          */
  86         u_int32_t (*build_segment)(integrity_checker_t *this, void *sym, size_t *len);
  87
  88         /**
  89          * Check both, on disk file integrity and loaded segment.
  90          *
  91          * @param name          name to lookup checksum
  92          * @param sym           a symbol to look up library and segment
  93          * @return                      TRUE if integrity tested successfully
  94          */
  95         bool (*check)(integrity_checker_t *this, char *name, void *sym);
  96
  97         /**
  98          * Destroy a integrity_checker_t.
  99          */
 100         void (*destroy)(integrity_checker_t *this);
 101 };
 102
 103 /**
 104  * Create a integrity_checker instance.
 105  *
 106  * @param checksum_library              library containing checksums
 107  */
 108 integrity_checker_t *integrity_checker_create(char *checksum_library);
 109
 110 #endif /** INTEGRITY_CHECKER_H_ @}*/