kopia lustrzana https://github.com/micropython/micropython-lib
python-stdlib/hmac: Update to work with built-in hash functions.
This library was non-functional unless used with the micropython-lib pure-Python implementation of hashlib, even if the device provides sha1 and sha256. This updates hmac to be significantly more RAM efficient (removes the 512-byte table), and functional with the built-in hash functions. The only unsupported function is "copy", but this is non-critical, and now fails with a NotSupportedError. Signed-off-by: Jim Mussared <jim.mussared@gmail.com>pull/447/merge
Jim Mussared
Damien George
rodzic
9fdf046e27
commit
f95260d7e3
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@ -1,161 +1,87 @@
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"""HMAC (Keyed-Hashing for Message Authentication) Python module.
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Implements the HMAC algorithm as described by RFC 2104.
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"""
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import warnings as _warnings
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# from _operator import _compare_digest as compare_digest
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import hashlib as _hashlib
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PendingDeprecationWarning = None
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RuntimeWarning = None
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trans_5C = bytes((x ^ 0x5C) for x in range(256))
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trans_36 = bytes((x ^ 0x36) for x in range(256))
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def translate(d, t):
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return bytes(t[x] for x in d)
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# The size of the digests returned by HMAC depends on the underlying
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# hashing module used. Use digest_size from the instance of HMAC instead.
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digest_size = None
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# Implements the hmac module from the Python standard library.
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class HMAC:
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"""RFC 2104 HMAC class. Also complies with RFC 4231.
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This supports the API for Cryptographic Hash Functions (PEP 247).
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"""
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blocksize = 64 # 512-bit HMAC; can be changed in subclasses.
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def __init__(self, key, msg=None, digestmod=None):
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"""Create a new HMAC object.
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key: key for the keyed hash object.
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msg: Initial input for the hash, if provided.
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digestmod: A module supporting PEP 247. *OR*
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A hashlib constructor returning a new hash object. *OR*
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A hash name suitable for hashlib.new().
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Defaults to hashlib.md5.
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Implicit default to hashlib.md5 is deprecated and will be
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removed in Python 3.6.
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Note: key and msg must be a bytes or bytearray objects.
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"""
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if not isinstance(key, (bytes, bytearray)):
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raise TypeError("key: expected bytes or bytearray, but got %r" % type(key).__name__)
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raise TypeError("key: expected bytes/bytearray")
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import hashlib
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if digestmod is None:
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_warnings.warn(
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"HMAC() without an explicit digestmod argument " "is deprecated.",
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PendingDeprecationWarning,
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2,
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)
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digestmod = _hashlib.md5
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# TODO: Default hash algorithm is now deprecated.
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digestmod = hashlib.md5
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if callable(digestmod):
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self.digest_cons = digestmod
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# A hashlib constructor returning a new hash object.
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make_hash = digestmod # A
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elif isinstance(digestmod, str):
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self.digest_cons = lambda d=b"": _hashlib.new(digestmod, d)
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# A hash name suitable for hashlib.new().
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make_hash = lambda d=b"": hashlib.new(digestmod, d) # B
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else:
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self.digest_cons = lambda d=b"": digestmod.new(d)
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# A module supporting PEP 247.
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make_hash = digestmod.new # C
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self.outer = self.digest_cons()
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self.inner = self.digest_cons()
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self.digest_size = self.inner.digest_size
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self._outer = make_hash()
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self._inner = make_hash()
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if hasattr(self.inner, "block_size"):
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blocksize = self.inner.block_size
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if blocksize < 16:
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_warnings.warn(
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"block_size of %d seems too small; using our "
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"default of %d." % (blocksize, self.blocksize),
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RuntimeWarning,
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2,
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)
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blocksize = self.blocksize
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else:
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_warnings.warn(
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"No block_size attribute on given digest object; "
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"Assuming %d." % (self.blocksize),
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RuntimeWarning,
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2,
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)
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blocksize = self.blocksize
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self.digest_size = getattr(self._inner, "digest_size", None)
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# If the provided hash doesn't support block_size (e.g. built-in
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# hashlib), 64 is the correct default for all built-in hash
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# functions (md5, sha1, sha256).
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self.block_size = getattr(self._inner, "block_size", 64)
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# self.blocksize is the default blocksize. self.block_size is
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# effective block size as well as the public API attribute.
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self.block_size = blocksize
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# Truncate to digest_size if greater than block_size.
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if len(key) > self.block_size:
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key = make_hash(key).digest()
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if len(key) > blocksize:
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key = self.digest_cons(key).digest()
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# Pad to block size.
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key = key + bytes(self.block_size - len(key))
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self._outer.update(bytes(x ^ 0x5C for x in key))
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self._inner.update(bytes(x ^ 0x36 for x in key))
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key = key + bytes(blocksize - len(key))
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self.outer.update(translate(key, trans_5C))
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self.inner.update(translate(key, trans_36))
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if msg is not None:
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self.update(msg)
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@property
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def name(self):
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return "hmac-" + self.inner.name
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return "hmac-" + getattr(self._inner, "name", type(self._inner).__name__)
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def update(self, msg):
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"""Update this hashing object with the string msg."""
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self.inner.update(msg)
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self._inner.update(msg)
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def copy(self):
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"""Return a separate copy of this hashing object.
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An update to this copy won't affect the original object.
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"""
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if not hasattr(self._inner, "copy"):
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# Not supported for built-in hash functions.
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raise NotImplementedError()
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# Call __new__ directly to avoid the expensive __init__.
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other = self.__class__.__new__(self.__class__)
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other.digest_cons = self.digest_cons
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other.block_size = self.block_size
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other.digest_size = self.digest_size
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other.inner = self.inner.copy()
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other.outer = self.outer.copy()
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other._inner = self._inner.copy()
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other._outer = self._outer.copy()
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return other
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def _current(self):
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"""Return a hash object for the current state.
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To be used only internally with digest() and hexdigest().
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"""
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h = self.outer.copy()
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h.update(self.inner.digest())
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h = self._outer
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if hasattr(h, "copy"):
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# built-in hash functions don't support this, and as a result,
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# digest() will finalise the hmac and further calls to
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# update/digest will fail.
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h = h.copy()
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h.update(self._inner.digest())
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return h
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def digest(self):
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"""Return the hash value of this hashing object.
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This returns a string containing 8-bit data. The object is
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not altered in any way by this function; you can continue
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updating the object after calling this function.
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"""
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h = self._current()
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return h.digest()
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def hexdigest(self):
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"""Like digest(), but returns a string of hexadecimal digits instead."""
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h = self._current()
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return h.hexdigest()
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import binascii
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return str(binascii.hexlify(self.digest()), "utf-8")
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def new(key, msg=None, digestmod=None):
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"""Create a new hashing object and return it.
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key: The starting key for the hash.
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msg: if available, will immediately be hashed into the object's starting
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state.
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You can now feed arbitrary strings into the object using its update()
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method, and can ask for the hash value at any time by calling its digest()
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method.
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"""
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return HMAC(key, msg, digestmod)
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@ -1,4 +1,3 @@
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srctype = cpython
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type = module
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version = 3.4.2-3
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depends = warnings, hashlib
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@ -1,10 +1,14 @@
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import hmac
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from hashlib.sha256 import sha256
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from hashlib.sha512 import sha512
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# Uncomment to use micropython-lib hashlib (supports sha512)
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# import sys
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# sys.path.append('../hashlib')
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import hashlib
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msg = b"zlutoucky kun upel dabelske ody"
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dig = hmac.new(b"1234567890", msg=msg, digestmod=sha256).hexdigest()
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dig = hmac.new(b"1234567890", msg=msg, digestmod=hashlib.sha256).hexdigest()
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print("c735e751e36b08fb01e25794bdb15e7289b82aecdb652c8f4f72f307b39dad39")
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print(dig)
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@ -12,22 +16,25 @@ print(dig)
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if dig != "c735e751e36b08fb01e25794bdb15e7289b82aecdb652c8f4f72f307b39dad39":
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raise Exception("Error")
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dig = hmac.new(b"1234567890", msg=msg, digestmod=sha512).hexdigest()
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if hasattr(hashlib, "sha512"):
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dig = hmac.new(b"1234567890", msg=msg, digestmod=hashlib.sha512).hexdigest()
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print(
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"59942f31b6f5473fb4eb630fabf5358a49bc11d24ebc83b114b4af30d6ef47ea14b673f478586f520a0b9c53b27c8f8dd618c165ef586195bd4e98293d34df1a"
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)
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print(dig)
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print(
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"59942f31b6f5473fb4eb630fabf5358a49bc11d24ebc83b114b4af30d6ef47ea14b673f478586f520a0b9c53b27c8f8dd618c165ef586195bd4e98293d34df1a"
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)
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print(dig)
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if (
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dig
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!= "59942f31b6f5473fb4eb630fabf5358a49bc11d24ebc83b114b4af30d6ef47ea14b673f478586f520a0b9c53b27c8f8dd618c165ef586195bd4e98293d34df1a"
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):
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raise Exception("Error")
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if (
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dig
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!= "59942f31b6f5473fb4eb630fabf5358a49bc11d24ebc83b114b4af30d6ef47ea14b673f478586f520a0b9c53b27c8f8dd618c165ef586195bd4e98293d34df1a"
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):
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raise Exception("Error")
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else:
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print("sha512 not supported")
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key = b"\x06\x1au\x90|Xz;o\x1b<\xafGL\xbfn\x8a\xc94YPfC^\xb9\xdd)\x7f\xaf\x85\xa1\xed\x82\xbexp\xaf\x13\x1a\x9d"
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dig = hmac.new(key[:20], msg=msg, digestmod=sha256).hexdigest()
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dig = hmac.new(key[:20], msg=msg, digestmod=hashlib.sha256).hexdigest()
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print("59e332b881df09fdecf569c8b142b27fc989638720aeda2813f82442b6e3d91b")
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print(dig)
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@ -35,7 +42,7 @@ print(dig)
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if dig != "59e332b881df09fdecf569c8b142b27fc989638720aeda2813f82442b6e3d91b":
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raise Exception("Error")
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dig = hmac.new(key[:32], msg=msg, digestmod=sha256).hexdigest()
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dig = hmac.new(key[:32], msg=msg, digestmod=hashlib.sha256).hexdigest()
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print("b72fed815cd71acfa3a2f5cf2343679565fa18e7cd92226ab443aabd1fd7b7b0")
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print(dig)
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@ -43,7 +50,7 @@ print(dig)
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if dig != "b72fed815cd71acfa3a2f5cf2343679565fa18e7cd92226ab443aabd1fd7b7b0":
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raise Exception("Error")
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dig = hmac.new(key, msg=msg, digestmod=sha256).hexdigest()
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dig = hmac.new(key, msg=msg, digestmod=hashlib.sha256).hexdigest()
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print("4e51beae6c2b0f90bb3e99d8e93a32d168b6c1e9b7d2130e2d668a3b3e10358d")
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print(dig)
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