/*

Copyright (c) 2007-2013. The YARA Authors. All Rights Reserved.

Redistribution and use in source and binary forms, with or without modification,

are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this

list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,

this list of conditions and the following disclaimer in the documentation and/or

other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors

may be used to endorse or promote products derived from this software without

specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND

ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR

ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON

ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

#if !defined(_WIN32) && !defined(__CYGWIN__)

#include <sys/stat.h>

#include <dirent.h>

#include <unistd.h>

#include <inttypes.h>

#else

#include <windows.h>

#define PRIx64 "I64x"

#define PRId64 "I64d"

#endif

#include <time.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <ctype.h>

#include <yara.h>

#include "args.h"

#include "common.h"

#include "threading.h"

#define ERROR_COULD_NOT_CREATE_THREAD 100

#ifndef MAX_PATH

#define MAX_PATH 256

#endif

#ifndef min

#define min(x, y) ((x < y) ? (x) : (y))

#endif

#ifdef _MSC_VER

#define snprintf _snprintf

#define strdup _strdup

#endif

#define MAX_QUEUED_FILES 64

typedef struct _MODULE_DATA

} MODULE_DATA;

typedef struct _CALLBACK_ARGS

} CALLBACK_ARGS;

typedef struct _THREAD_ARGS

} THREAD_ARGS;

typedef struct _QUEUED_FILE

} QUEUED_FILE;

typedef struct COMPILER_RESULTS

} COMPILER_RESULTS;

#define MAX_ARGS_TAG 32

#define MAX_ARGS_IDENTIFIER 32

#define MAX_ARGS_EXT_VAR 32

#define MAX_ARGS_MODULE_DATA 32

static char* atom_quality_table;

static char* tags[MAX_ARGS_TAG + 1];

static char* identifiers[MAX_ARGS_IDENTIFIER + 1];

static char* ext_vars[MAX_ARGS_EXT_VAR + 1];

static char* modules_data[MAX_ARGS_EXT_VAR + 1];

static bool recursive_search = false;

static bool show_module_data = false;

static bool show_tags = false;

static bool show_stats = false;

static bool show_strings = false;

static bool show_string_length = false;

static bool show_meta = false;

static bool show_namespace = false;

static bool show_version = false;

static bool show_help = false;

static bool ignore_warnings = false;

static bool fast_scan = false;

static bool negate = false;

static bool print_count_only = false;

static bool fail_on_warnings = false;

static bool rules_are_compiled = false;

static int total_count = 0;

static int limit = 0;

static int timeout = 1000000;

static int stack_size = DEFAULT_STACK_SIZE;

static int threads = YR_MAX_THREADS;

static int max_strings_per_rule = DEFAULT_MAX_STRINGS_PER_RULE;

#define USAGE_STRING \

args_option_t options[] =

{

OPT_STRING(0, "atom-quality-table", &atom_quality_table,

"path to a file with the atom quality table", "FILE"),

OPT_BOOLEAN('C', "compiled-rules", &rules_are_compiled,

"load compiled rules"),

OPT_BOOLEAN('c', "count", &print_count_only,

"print only number of matches"),

OPT_STRING_MULTI('d', "define", &ext_vars, MAX_ARGS_EXT_VAR,

"define external variable", "VAR=VALUE"),

OPT_BOOLEAN(0, "fail-on-warnings", &fail_on_warnings,

"fail on warnings"),

OPT_BOOLEAN('f', "fast-scan", &fast_scan,

"fast matching mode"),

OPT_BOOLEAN('h', "help", &show_help,

"show this help and exit"),

OPT_STRING_MULTI('i', "identifier", &identifiers, MAX_ARGS_IDENTIFIER,

"print only rules named IDENTIFIER", "IDENTIFIER"),

OPT_INTEGER('l', "max-rules", &limit,

"abort scanning after matching a NUMBER of rules", "NUMBER"),

OPT_INTEGER(0, "max-strings-per-rule", &max_strings_per_rule,

"set maximum number of strings per rule (default=10000)", "NUMBER"),

OPT_STRING_MULTI('x', "module-data", &modules_data, MAX_ARGS_MODULE_DATA,

"pass FILE's content as extra data to MODULE", "MODULE=FILE"),

OPT_BOOLEAN('n', "negate", &negate,

"print only not satisfied rules (negate)", NULL),

OPT_BOOLEAN('w', "no-warnings", &ignore_warnings,

"disable warnings"),

OPT_BOOLEAN('m', "print-meta", &show_meta,

"print metadata"),

OPT_BOOLEAN('D', "print-module-data", &show_module_data,

"print module data"),

OPT_BOOLEAN('e', "print-namespace", &show_namespace,

"print rules' namespace"),

OPT_BOOLEAN('S', "print-stats", &show_stats,

"print rules' statistics"),

OPT_BOOLEAN('s', "print-strings", &show_strings,

"print matching strings"),

OPT_BOOLEAN('L', "print-string-length", &show_string_length,

"print length of matched strings"),

OPT_BOOLEAN('g', "print-tags", &show_tags,

"print tags"),

OPT_BOOLEAN('r', "recursive", &recursive_search,

"recursively search directories"),

OPT_INTEGER('k', "stack-size", &stack_size,

"set maximum stack size (default=16384)", "SLOTS"),

OPT_STRING_MULTI('t', "tag", &tags, MAX_ARGS_TAG,

"print only rules tagged as TAG", "TAG"),

OPT_INTEGER('p', "threads", &threads,

"use the specified NUMBER of threads to scan a directory", "NUMBER"),

OPT_INTEGER('a', "timeout", &timeout,

"abort scanning after the given number of SECONDS", "SECONDS"),

OPT_BOOLEAN('v', "version", &show_version,

"show version information"),

OPT_END()

};

// file_queue is size-limited queue stored as a circular array, files are

// removed from queue_head position and new files are added at queue_tail

// position. The array has room for one extra element to avoid queue_head

// being equal to queue_tail in a full queue. The only situation where

// queue_head == queue_tail is when queue is empty.

QUEUED_FILE file_queue[MAX_QUEUED_FILES + 1];

int queue_head;

int queue_tail;

SEMAPHORE used_slots;

SEMAPHORE unused_slots;

MUTEX queue_mutex;

MUTEX output_mutex;

MODULE_DATA* modules_data_list = NULL;

static int file_queue_init()

{

int result;

queue_tail = 0;

queue_head = 0;

result = mutex_init(&queue_mutex);

if (result != 0)

return result;

result = semaphore_init(&used_slots, 0);

if (result != 0)

return result;

return semaphore_init(&unused_slots, MAX_QUEUED_FILES);

}

static void file_queue_destroy()

{

mutex_destroy(&queue_mutex);

semaphore_destroy(&unused_slots);

semaphore_destroy(&used_slots);

}

static void file_queue_finish()

{

int i;

for (i = 0; i < YR_MAX_THREADS; i++)

semaphore_release(&used_slots);

}

static void file_queue_put(

const char* file_path)

{

semaphore_wait(&unused_slots);

mutex_lock(&queue_mutex);

file_queue[queue_tail].path = strdup(file_path);

queue_tail = (queue_tail + 1) % (MAX_QUEUED_FILES + 1);

mutex_unlock(&queue_mutex);

semaphore_release(&used_slots);

}

static char* file_queue_get()

{

char* result;

semaphore_wait(&used_slots);

mutex_lock(&queue_mutex);

if (queue_head == queue_tail) // queue is empty

{

result = NULL;

}

else

{

result = file_queue[queue_head].path;

queue_head = (queue_head + 1) % (MAX_QUEUED_FILES + 1);

}

mutex_unlock(&queue_mutex);

semaphore_release(&unused_slots);

return result;

}

#if defined(_WIN32) || defined(__CYGWIN__)

static bool is_directory(

const char* path)

{

DWORD attributes = GetFileAttributes(path);

if (attributes != INVALID_FILE_ATTRIBUTES &&

attributes & FILE_ATTRIBUTE_DIRECTORY)

return true;

else

return false;

}

static void scan_dir(

const char* dir,

int recursive,

time_t start_time)

{

static char path_and_mask[MAX_PATH];

snprintf(path_and_mask, sizeof(path_and_mask), "%s\\*", dir);

WIN32_FIND_DATA FindFileData;

HANDLE hFind = FindFirstFile(path_and_mask, &FindFileData);

if (hFind != INVALID_HANDLE_VALUE)

{

do

{

char full_path[MAX_PATH];

snprintf(full_path, sizeof(full_path), "%s\\%s",

dir, FindFileData.cFileName);

if (!(FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY))

{

file_queue_put(full_path);

}

else if (recursive &&

strcmp(FindFileData.cFileName, ".") != 0 &&

strcmp(FindFileData.cFileName, "..") != 0)

{

scan_dir(full_path, recursive, start_time);

}

} while (FindNextFile(hFind, &FindFileData));

FindClose(hFind);

}

}

#else

static bool is_directory(

const char* path)

{

struct stat st;

if (stat(path,&st) == 0)

return S_ISDIR(st.st_mode);

return 0;

}

static void scan_dir(

const char* dir,

int recursive,

time_t start_time)

{

DIR* dp = opendir(dir);

if (dp)

{

struct dirent* de = readdir(dp);

while (de && difftime(time(NULL), start_time) < timeout)

{

char full_path[MAX_PATH];

struct stat st;

snprintf(full_path, sizeof(full_path), "%s/%s", dir, de->d_name);

int err = lstat(full_path, &st);

if (err == 0)

{

if(S_ISREG(st.st_mode))

{

file_queue_put(full_path);

}

else if(recursive &&

S_ISDIR(st.st_mode) &&

!S_ISLNK(st.st_mode) &&

strcmp(de->d_name, ".") != 0 &&

strcmp(de->d_name, "..") != 0)

{

scan_dir(full_path, recursive, start_time);

}

}

de = readdir(dp);

}

closedir(dp);

}

}

#endif

static void print_string(

const uint8_t* data,

int length)

{

for (int i = 0; i < length; i++)

{

if (data[i] >= 32 && data[i] <= 126)

printf("%c", data[i]);

else

printf("\\x%02X", data[i]);

}

printf("\n");

}

static char cescapes[] =

{

0 , 0 , 0 , 0 , 0 , 0 , 0 , 'a',

'b', 't', 'n', 'v', 'f', 'r', 0 , 0 ,

0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 ,

0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 ,

};

static void print_escaped(

const uint8_t* data,

size_t length)

{

size_t i;

for (i = 0; i < length; i++)

{

switch (data[i])

{

case '\"':

case '\'':

case '\\':

printf("\\%c", data[i]);

break;

default:

if (data[i] >= 127)

printf("\\%03o", data[i]);

else if (data[i] >= 32)

putchar(data[i]);

else if (cescapes[data[i]] != 0)

printf("\\%c", cescapes[data[i]]);

else

printf("\\%03o", data[i]);

}

}

}

static void print_hex_string(

const uint8_t* data,

int length)

{

for (int i = 0; i < min(32, length); i++)

printf("%s%02X", (i == 0 ? "" : " "), data[i]);

puts(length > 32 ? " ..." : "");

}

static void print_error(

int error)

{

switch (error)

{

case ERROR_SUCCESS:

break;

case ERROR_COULD_NOT_ATTACH_TO_PROCESS:

fprintf(stderr, "can not attach to process (try running as root)\n");

break;

case ERROR_INSUFFICIENT_MEMORY:

fprintf(stderr, "not enough memory\n");

break;

case ERROR_SCAN_TIMEOUT:

fprintf(stderr, "scanning timed out\n");

break;

case ERROR_COULD_NOT_OPEN_FILE:

fprintf(stderr, "could not open file\n");

break;

case ERROR_UNSUPPORTED_FILE_VERSION:

fprintf(stderr, "rules were compiled with a different version of YARA\n");

break;

case ERROR_INVALID_FILE:

fprintf(stderr, "invalid compiled rules file.\n");

break;

case ERROR_CORRUPT_FILE:

fprintf(stderr, "corrupt compiled rules file.\n");

break;

case ERROR_EXEC_STACK_OVERFLOW:

fprintf(stderr, "stack overflow while evaluating condition "

"(see --stack-size argument) \n");

break;

case ERROR_INVALID_EXTERNAL_VARIABLE_TYPE:

fprintf(stderr, "invalid type for external variable\n");

break;

case ERROR_TOO_MANY_MATCHES:

fprintf(stderr, "too many matches\n");

break;

default:

fprintf(stderr, "error: %d\n", error);

break;

}

}

static void print_scanner_error(

YR_SCANNER* scanner,

int error)

{

YR_RULE* rule = yr_scanner_last_error_rule(scanner);

YR_STRING* string = yr_scanner_last_error_string(scanner);

if (rule != NULL && string != NULL)

{

fprintf(

stderr,

"string \"%s\" in rule \"%s\" caused ",

string->identifier,

rule->identifier);

}

else if (rule != NULL)

{

fprintf(

stderr,

"rule \"%s\" caused ",

rule->identifier);

}

print_error(error);

}

static void print_compiler_error(

void* user_data)

{

if (error_level == YARA_ERROR_LEVEL_ERROR)

{

fprintf(stderr, "%s(%d): error: %s\n", file_name, line_number, message);

}

else if (!ignore_warnings)

{

COMPILER_RESULTS* compiler_results = (COMPILER_RESULTS*) user_data;

compiler_results->warnings++;

fprintf(stderr, "%s(%d): warning: %s\n", file_name, line_number, message);

}

}

static void print_rules_stats(

YR_RULES* rules)

{

YR_RULES_STATS stats;

int t = sizeof(stats.top_ac_match_list_lengths) /

sizeof(stats.top_ac_match_list_lengths[0]);

int result = yr_rules_get_stats(rules, &stats);

if (result != ERROR_SUCCESS)

{

print_error(result);

return;

}

printf(

"size of AC transition table : %d\n",

stats.ac_tables_size);

printf(

"average length of AC matches lists : %f\n",

stats.ac_average_match_list_length);

printf(

"number of rules : %d\n",

stats.rules);

printf(

"number of strings : %d\n",

stats.strings);

printf(

"number of AC matches : %d\n",

stats.ac_matches);

printf(

"number of AC matches in root node : %d\n",

stats.ac_root_match_list_length);

printf("number of AC matches in top %d longest lists\n", t);

for (int i = 0; i < t; i++)

printf(" %3d: %d\n", i + 1, stats.top_ac_match_list_lengths[i]);

printf("match list length percentiles\n");

for (int i = 0; i <= 100; i++)

printf(" %3d: %d\n", i, stats.ac_match_list_length_pctls[i]);

}

static int handle_message(

int message,

YR_RULE* rule,

void* data)

{

const char* tag;

bool show = true;

if (tags[0] != NULL)

{

// The user specified one or more -t <tag> arguments, let's show this rule

// only if it's tagged with some of the specified tags.

show = false;

for (int i = 0; !show && tags[i] != NULL; i++)

{

yr_rule_tags_foreach(rule, tag)

{

if (strcmp(tag, tags[i]) == 0)

{

show = true;

break;

}

}

}

}

if (identifiers[0] != NULL)

{

// The user specified one or more -i <identifier> arguments, let's show

// this rule only if it's identifier is among of the provided ones.

show = false;

for (int i = 0; !show && identifiers[i] != NULL; i++)

{

if (strcmp(identifiers[i], rule->identifier) == 0)

{

show = true;

break;

}

}

}

bool is_matching = (message == CALLBACK_MSG_RULE_MATCHING);

show = show && ((!negate && is_matching) || (negate && !is_matching));

if (show && !print_count_only)

{

mutex_lock(&output_mutex);

if (show_namespace)

printf("%s:", rule->ns->name);

printf("%s ", rule->identifier);

if (show_tags)

{

printf("[");

yr_rule_tags_foreach(rule, tag)

{

// print a comma except for the first tag

if (tag != rule->tags)

printf(",");

printf("%s", tag);

}

printf("] ");

}

// Show meta-data.

if (show_meta)

{

YR_META* meta;

printf("[");

yr_rule_metas_foreach(rule, meta)

{

if (meta != rule->metas)

printf(",");

if (meta->type == META_TYPE_INTEGER)

{

printf("%s=%" PRId64, meta->identifier, meta->integer);

}

else if (meta->type == META_TYPE_BOOLEAN)

{

printf("%s=%s", meta->identifier, meta->integer ? "true" : "false");

}

else

{

printf("%s=\"", meta->identifier);

print_escaped((uint8_t*) (meta->string), strlen(meta->string));

putchar('"');

}

}

printf("] ");

}

printf("%s\n", ((CALLBACK_ARGS*) data)->file_path);

// Show matched strings.

if (show_strings || show_string_length)

{

YR_STRING* string;

yr_rule_strings_foreach(rule, string)

{

YR_MATCH* match;

yr_string_matches_foreach(string, match)

{

if (show_string_length)

printf("0x%" PRIx64 ":%d:%s",

match->base + match->offset,

match->data_length,

string->identifier);

else

printf("0x%" PRIx64 ":%s",

match->base + match->offset,

string->identifier);

if (show_strings)

{

printf(": ");

if (STRING_IS_HEX(string))

print_hex_string(match->data, match->data_length);

else

print_string(match->data, match->data_length);

}

else

{

printf("\n");

}

}

}

}

mutex_unlock(&output_mutex);

}

if (is_matching)

{

((CALLBACK_ARGS*) data)->current_count++;

total_count++;

}

if (limit != 0 && total_count >= limit)

return CALLBACK_ABORT;

return CALLBACK_CONTINUE;

}

static int callback(

int message,

void* message_data,

void* user_data)

{

YR_MODULE_IMPORT* mi;

YR_OBJECT* object;

MODULE_DATA* module_data;

switch(message)

{

case CALLBACK_MSG_RULE_MATCHING:

case CALLBACK_MSG_RULE_NOT_MATCHING:

return handle_message(message, (YR_RULE*) message_data, user_data);

case CALLBACK_MSG_IMPORT_MODULE:

mi = (YR_MODULE_IMPORT*) message_data;

module_data = modules_data_list;

while (module_data != NULL)

{

if (strcmp(module_data->module_name, mi->module_name) == 0)

{

mi->module_data = (void*) module_data->mapped_file.data;

mi->module_data_size = module_data->mapped_file.size;

break;

}

module_data = module_data->next;

}

return CALLBACK_CONTINUE;

case CALLBACK_MSG_MODULE_IMPORTED:

if (show_module_data)

{

object = (YR_OBJECT*) message_data;

mutex_lock(&output_mutex);

yr_object_print_data(object, 0, 1);

printf("\n");

mutex_unlock(&output_mutex);

}

return CALLBACK_CONTINUE;

}

return CALLBACK_ERROR;

}

#if defined(_WIN32) || defined(__CYGWIN__)

static DWORD WINAPI scanning_thread(LPVOID param)

#else

static void* scanning_thread(void* param)

#endif

{

int result = ERROR_SUCCESS;

THREAD_ARGS* args = (THREAD_ARGS*) param;

char* file_path = file_queue_get();

while (file_path != NULL)

{

args->callback_args.current_count = 0;

args->callback_args.file_path = file_path;

int elapsed_time = (int) difftime(time(NULL), args->start_time);

if (elapsed_time < timeout)

{

yr_scanner_set_timeout(args->scanner, timeout - elapsed_time);

result = yr_scanner_scan_file(args->scanner, file_path);

if (print_count_only)

{

mutex_lock(&output_mutex);

printf("%s: %d\n", file_path, args->callback_args.current_count);

mutex_unlock(&output_mutex);

}

if (result != ERROR_SUCCESS)

{

mutex_lock(&output_mutex);

fprintf(stderr, "error scanning %s: ", file_path);

print_scanner_error(args->scanner, result);

mutex_unlock(&output_mutex);

}

free(file_path);

file_path = file_queue_get();

}

else

{

file_path = NULL;

}

}

return 0;

}

static int define_external_variables(

YR_RULES* rules,

YR_COMPILER* compiler)

{

int result = ERROR_SUCCESS;

for (int i = 0; ext_vars[i] != NULL; i++)

{

char* equal_sign = strchr(ext_vars[i], '=');

if (!equal_sign)

{

fprintf(stderr, "error: wrong syntax for `-d` option.\n");

return ERROR_SUCCESS;

}

// Replace the equal sign with null character to split the external

// variable definition (i.e: myvar=somevalue) in two strings: identifier

// and value.

*equal_sign = '\0';

char* identifier = ext_vars[i];

char* value = equal_sign + 1;

if (is_float(value))

{

if (rules != NULL)

result = yr_rules_define_float_variable(

rules,

identifier,

atof(value));

if (compiler != NULL)

result = yr_compiler_define_float_variable(

compiler,

identifier,

atof(value));

}

else if (is_integer(value))

{

if (rules != NULL)

result = yr_rules_define_integer_variable(

rules,

identifier,

atoi(value));

if (compiler != NULL)

result = yr_compiler_define_integer_variable(

compiler,

identifier,

atoi(value));

}

else if (strcmp(value, "true") == 0 || strcmp(value, "false") == 0)

{

if (rules != NULL)

result = yr_rules_define_boolean_variable(

rules,

identifier,

strcmp(value, "true") == 0);

if (compiler != NULL)

result = yr_compiler_define_boolean_variable(

compiler,

identifier,

strcmp(value, "true") == 0);

}

else

{

if (rules != NULL)

result = yr_rules_define_string_variable(

rules,

identifier,