def extract(self, offset, description, file_name, size, name=None):
'''
Extract an embedded file from the target file, if it matches an extract rule.
Called automatically by Binwalk.scan().
@offset - Offset inside the target file to begin the extraction.
@description - Description of the embedded file to extract, as returned by libmagic.
@file_name - Path to the target file.
@size - Number of bytes to extract.
@name - Name to save the file as.
Returns the name of the extracted file (blank string if nothing was extracted).
'''
fname = ''
recurse = False
original_dir = os.getcwd()
rules = self.match(description)
file_path = os.path.realpath(file_name)
# No extraction rules for this file
if not rules:
return (None, None, False)
else:
binwalk.core.common.debug("Found %d matching extraction rules" % len(rules))
# Generate the output directory name where extracted files will be stored
output_directory = self.build_output_directory(file_name)
# Extract to end of file if no size was specified
if not size:
size = file_size(file_path) - offset
if os.path.isfile(file_path):
os.chdir(output_directory)
# Loop through each extraction rule until one succeeds
for i in range(0, len(rules)):
rule = rules[i]
# Make sure we don't recurse into any extracted directories if instructed not to
if rule['recurse'] in [True, False]:
recurse = rule['recurse']
else:
recurse = True
# Copy out the data to disk, if we haven't already
fname = self._dd(file_path, offset, size, rule['extension'], output_file_name=name)
# If there was a command specified for this rule, try to execute it.
# If execution fails, the next rule will be attempted.
if rule['cmd']:
# Note the hash of the original file; if --rm is specified and the
# extraction utility modifies the original file rather than creating
# a new one (AFAIK none currently do, but could happen in the future),
# we don't want to remove this file.
if self.remove_after_execute:
fname_md5 = file_md5(fname)
# Execute the specified command against the extracted file
if self.run_extractors:
extract_ok = self.execute(rule['cmd'], fname, rule['codes'])
else:
extract_ok = True
# Only clean up files if remove_after_execute was specified
if extract_ok == True and self.remove_after_execute:
# Remove the original file that we extracted,
# if it has not been modified by the extractor.
try:
if file_md5(fname) == fname_md5:
os.unlink(fname)
except KeyboardInterrupt as e:
raise e
except Exception as e:
pass
# If the command executed OK, don't try any more rules
if extract_ok == True:
break
# Else, remove the extracted file if this isn't the last rule in the list.
# If it is the last rule, leave the file on disk for the user to examine.
elif i != (len(rules)-1):
try:
os.unlink(fname)
except KeyboardInterrupt as e:
raise e
except Exception as e:
pass
# If there was no command to execute, just use the first rule
else:
break
os.chdir(original_dir)
return (output_directory, fname, recurse)
def extract(self, offset, description, file_name, size, name=None):
'''
Extract an embedded file from the target file, if it matches an extract rule.
Called automatically by Binwalk.scan().
@offset - Offset inside the target file to begin the extraction.
@description - Description of the embedded file to extract, as returned by libmagic.
@file_name - Path to the target file.
@size - Number of bytes to extract.
@name - Name to save the file as.
Returns the name of the extracted file (blank string if nothing was extracted).
'''
fname = ''
recurse = False
original_dir = os.getcwd()
rules = self.match(description)
file_path = os.path.realpath(file_name)
# No extraction rules for this file
if not rules:
return (None, None, False)
else:
binwalk.core.common.debug("Found %d matching extraction rules" % len(rules))
# Generate the output directory name where extracted files will be stored
output_directory = self.build_output_directory(file_name)
# Extract to end of file if no size was specified
if not size:
size = file_size(file_path) - offset
if os.path.isfile(file_path):
os.chdir(output_directory)
# Loop through each extraction rule until one succeeds
for i in range(0, len(rules)):
rule = rules[i]
# Make sure we don't recurse into any extracted directories if instructed not to
if rule['recurse'] in [True, False]:
recurse = rule['recurse']
else:
recurse = True
# Copy out the data to disk, if we haven't already
fname = self._dd(file_path, offset, size, rule['extension'], output_file_name=name)
# If there was a command specified for this rule, try to execute it.
# If execution fails, the next rule will be attempted.
if rule['cmd']:
# Note the hash of the original file; if --rm is specified and the
# extraction utility modifies the original file rather than creating
# a new one (AFAIK none currently do, but could happen in the future),
# we don't want to remove this file.
if self.remove_after_execute:
fname_md5 = file_md5(fname)
# Execute the specified command against the extracted file
if self.run_extractors:
extract_ok = self.execute(rule['cmd'], fname, rule['codes'])
else:
extract_ok = True
# Only clean up files if remove_after_execute was specified
if extract_ok == True and self.remove_after_execute:
# Remove the original file that we extracted,
# if it has not been modified by the extractor.
try:
if file_md5(fname) == fname_md5:
os.unlink(fname)
except KeyboardInterrupt as e:
raise e
except Exception as e:
pass
# If the command executed OK, don't try any more rules
if extract_ok == True:
break
# Else, remove the extracted file if this isn't the last rule in the list.
# If it is the last rule, leave the file on disk for the user to examine.
elif i != (len(rules)-1):
try:
os.unlink(fname)
except KeyboardInterrupt as e:
raise e
except Exception as e:
pass
# If there was no command to execute, just use the first rule
else:
break
os.chdir(original_dir)
return (output_directory, fname, recurse)
