diff options
Diffstat (limited to 'Lib/hmac.py')
| -rw-r--r-- | Lib/hmac.py | 86 |
1 files changed, 51 insertions, 35 deletions
diff --git a/Lib/hmac.py b/Lib/hmac.py index 180bc37..8b4f920 100644 --- a/Lib/hmac.py +++ b/Lib/hmac.py @@ -8,11 +8,12 @@ try: import _hashlib as _hashopenssl except ImportError: _hashopenssl = None - _openssl_md_meths = None + _functype = None from _operator import _compare_digest as compare_digest else: - _openssl_md_meths = frozenset(_hashopenssl.openssl_md_meth_names) compare_digest = _hashopenssl.compare_digest + _functype = type(_hashopenssl.openssl_sha256) # builtin type + import hashlib as _hashlib trans_5C = bytes((x ^ 0x5C) for x in range(256)) @@ -23,7 +24,6 @@ trans_36 = bytes((x ^ 0x36) for x in range(256)) digest_size = None - class HMAC: """RFC 2104 HMAC class. Also complies with RFC 4231. @@ -32,7 +32,7 @@ class HMAC: blocksize = 64 # 512-bit HMAC; can be changed in subclasses. __slots__ = ( - "_digest_cons", "_inner", "_outer", "block_size", "digest_size" + "_hmac", "_inner", "_outer", "block_size", "digest_size" ) def __init__(self, key, msg=None, digestmod=''): @@ -55,15 +55,30 @@ class HMAC: if not digestmod: raise TypeError("Missing required parameter 'digestmod'.") + if _hashopenssl and isinstance(digestmod, (str, _functype)): + try: + self._init_hmac(key, msg, digestmod) + except _hashopenssl.UnsupportedDigestmodError: + self._init_old(key, msg, digestmod) + else: + self._init_old(key, msg, digestmod) + + def _init_hmac(self, key, msg, digestmod): + self._hmac = _hashopenssl.hmac_new(key, msg, digestmod=digestmod) + self.digest_size = self._hmac.digest_size + self.block_size = self._hmac.block_size + + def _init_old(self, key, msg, digestmod): if callable(digestmod): - self._digest_cons = digestmod + digest_cons = digestmod elif isinstance(digestmod, str): - self._digest_cons = lambda d=b'': _hashlib.new(digestmod, d) + digest_cons = lambda d=b'': _hashlib.new(digestmod, d) else: - self._digest_cons = lambda d=b'': digestmod.new(d) + digest_cons = lambda d=b'': digestmod.new(d) - self._outer = self._digest_cons() - self._inner = self._digest_cons() + self._hmac = None + self._outer = digest_cons() + self._inner = digest_cons() self.digest_size = self._inner.digest_size if hasattr(self._inner, 'block_size'): @@ -79,13 +94,13 @@ class HMAC: RuntimeWarning, 2) blocksize = self.blocksize + if len(key) > blocksize: + key = digest_cons(key).digest() + # self.blocksize is the default blocksize. self.block_size is # effective block size as well as the public API attribute. self.block_size = blocksize - if len(key) > blocksize: - key = self._digest_cons(key).digest() - key = key.ljust(blocksize, b'\0') self._outer.update(key.translate(trans_5C)) self._inner.update(key.translate(trans_36)) @@ -94,23 +109,15 @@ class HMAC: @property def name(self): - return "hmac-" + self._inner.name - - @property - def digest_cons(self): - return self._digest_cons - - @property - def inner(self): - return self._inner - - @property - def outer(self): - return self._outer + if self._hmac: + return self._hmac.name + else: + return f"hmac-{self._inner.name}" def update(self, msg): """Feed data from msg into this hashing object.""" - self._inner.update(msg) + inst = self._hmac or self._inner + inst.update(msg) def copy(self): """Return a separate copy of this hashing object. @@ -119,10 +126,14 @@ class HMAC: """ # Call __new__ directly to avoid the expensive __init__. other = self.__class__.__new__(self.__class__) - other._digest_cons = self._digest_cons other.digest_size = self.digest_size - other._inner = self._inner.copy() - other._outer = self._outer.copy() + if self._hmac: + other._hmac = self._hmac.copy() + other._inner = other._outer = None + else: + other._hmac = None + other._inner = self._inner.copy() + other._outer = self._outer.copy() return other def _current(self): @@ -130,9 +141,12 @@ class HMAC: To be used only internally with digest() and hexdigest(). """ - h = self._outer.copy() - h.update(self._inner.digest()) - return h + if self._hmac: + return self._hmac + else: + h = self._outer.copy() + h.update(self._inner.digest()) + return h def digest(self): """Return the hash value of this hashing object. @@ -179,9 +193,11 @@ def digest(key, msg, digest): A hashlib constructor returning a new hash object. *OR* A module supporting PEP 247. """ - if (_hashopenssl is not None and - isinstance(digest, str) and digest in _openssl_md_meths): - return _hashopenssl.hmac_digest(key, msg, digest) + if _hashopenssl is not None and isinstance(digest, (str, _functype)): + try: + return _hashopenssl.hmac_digest(key, msg, digest) + except _hashopenssl.UnsupportedDigestmodError: + pass if callable(digest): digest_cons = digest |