def digest(self, flag=0):
"""Obtain the fuzzy hash.
It reports the hash for the concatenation of the data previously
fed using 'update' method.
Args:
flag: Is a bitwise or of 'FUZZY_FLAG_ELIMSEQ' and 'FUZZY_FLAG_NOTRUNC'
value (default value is zero).
Returns:
Fuzzy hash value (at a string format).
Raises:
TypeError: If a argument type is incorrect.
FuzzyHashError: If a function execution error occurred.
"""
if not isinstance(flag, int):
raise TypeError('Flag value must be of int type not "{}".'.format(
type(flag)))
if self._state is None:
raise FuzzyHashError(
'Unable to update hash object. Hash context error.')
try:
result = fuzzy_digest(self._state, flag)
except FuzzyHashError as err:
raise FuzzyHashError(
'Unable to compute digest of hash object. Error code: {}.'.
format(err)) from err
return result
def get_hash_buffer(buffer, encoding='utf-8'):
"""Compute the fuzzy hash of a buffer.
Args:
buffer: The data from which to get the hash (as a byte or string object).
encoding: Encoding is used if 'buffer' is string (default value is
'utf-8').
Returns:
The fuzzy hash of the buffer (at a string format).
Raises:
TypeError: If a argument type is incorrect.
FuzzyHashError: If a function execution error occurred or if the
'encoding' value is incorrect.
"""
if isinstance(buffer, six.text_type):
try:
buffer = buffer.encode(encoding)
except UnicodeEncodeError as err:
raise FuzzyHashError(
'Data encoding error. The "encoding" value cannot be "{}".'.
format(encoding))
if not isinstance(buffer, six.binary_type):
raise TypeError(
'Invalid data type. The data type cannot be "{}".'.format(
type(buffer)))
try:
result = fuzzy_hash_buf(buffer, len(buffer))
except FuzzyHashError as err:
raise FuzzyHashError(
'Unable to compute fuzzy hash. Error code: {}.'.format(
err)) from err
return result
def update(self, data, encoding='utf-8'):
"""Update the hash object with 'data'.
Args:
data: The data from which to get the hash (as a byte or string
object).
encoding: Encoding is used if 'data' is string (default value is
'utf-8').
Raises:
TypeError: If a argument type is incorrect.
FuzzyHashError: If a function execution error occurred or if the
'encoding' value is incorrect.
"""
if isinstance(data, six.text_type):
try:
data = data.encode(encoding)
except UnicodeEncodeError as err:
raise FuzzyHashError(
'Data encoding error. The "encoding" value cannot be "{}".'
.format(encoding)) from err
if not isinstance(data, six.binary_type):
raise TypeError(
'Invalid data type. The data type cannot be "{}".'.format(
type(data)))
if self._state is None:
raise FuzzyHashError(
'Unable to update hash object. Hash context error.')
try:
fuzzy_update(self._state, data, len(data))
except FuzzyHashError as err:
raise FuzzyHashError(
'Unable to update hash object. Error code: {}.'.format(
err)) from err
def compare(signature_1, signature_2):
"""Compare two fazzy hash signatures.
Args:
signature_1: The first fuzzy hash signature (at a string format).
signature_2: The second fuzzy hash signature (at a string format).
Returns:
The value from zero to 100 indicating the match score of the two
signatures. A match score of zero indicates the signatures did not match.
Raises:
TypeError: If a argument type is incorrect.
FuzzyHashError: If a function execution error occurred.
"""
if not isinstance(signature_1, six.text_type):
raise TypeError(
'Invalid first operand type. It cannot be "{}".'.format(
type(signature_1)))
if not isinstance(signature_2, six.text_type):
raise TypeError(
'Invalid second operand type. It cannot be "{}".'.format(
type(signature_2)))
try:
result = fuzzy_compare(signature_1, signature_2)
except FuzzyHashError as err:
raise FuzzyHashError(
'Unable to compare this fazzy hash signatures. Error code: {}.'.
format(err)) from err
return result
def digest_size(self):
"""Return digest size value.
Returns:
Digest size value.
Raises:
FuzzyHashError: If the digest size value cannot be returned.
"""
try:
result = len(self.digest().partition(':')[2])
except FuzzyHashError as err:
raise FuzzyHashError(
'Unable to return the digest size value.') from err
return result
def block_size(self):
"""Return block size value.
Returns:
Block size value used to compute fuzzy hash.
Raises:
FuzzyHashError: If the block size value cannot be returned.
"""
try:
result = int(self.digest().partition(':')[0])
except FuzzyHashError as err:
raise FuzzyHashError(
'Unable to return the block size value.') from err
return result
def copy(self):
"""Create the copy of the hash object.
The copy of of the hash object can be used with 'update' and
'digest' independently of the original.
Returns:
Copy of the hash object.
Raises:
FuzzyHashError: If an error occurred executing the function.
"""
try:
state_copy = fuzzy_clone(self._state)
except FuzzyHashError as err:
raise FuzzyHashError(
'Unable to clone hash object. Error code: {}.'.format(
err)) from err
result = FuzzyHash.__new__(FuzzyHash)
result._state = state_copy
return result
def __init__(self, data, encoding):
"""Initialize the hashing object.
Args:
data: The data from which to get the hash (as a byte object).
encoding: Encoding is used if 'data' is string.
Raises:
TypeError: If a argument type is incorrect.
FuzzyHashError: If a function execution error occurred or if the
'encoding' value is incorrect.
"""
self._name = 'ssdeep'
try:
self._state = fuzzy_new()
except FuzzyHashError as err:
self._state = None
raise FuzzyHashError(
'Unable to create hash context. Error code: {}.'.format(
err)) from err
if data != bytearray(b''):
self.update(data, encoding)
def get_hash_file(file_name):
"""Compute the fuzzy hash of a file.
Args:
file_name: The file to be hashed (at a string format).
Returns:
The fuzzy hash of the file (at a string format).
Raises:
IOError: If the file is not found or unavailable.
FuzzyHashError: If a function execution error occurred.
"""
if not os.path.isfile(file_name):
raise IOError('File "{}" not found.'.format(file_name))
if not os.access(file_name, os.R_OK):
raise IOError('File "{}" is not available.'.format(file_name))
try:
result = fuzzy_hash_filename(file_name)
except FuzzyHashError as err:
raise FuzzyHashError(
'Unable to compute fuzzy hash of file "{0}". Error code: {1}.'.
format(file_name, err)) from err
return result