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authorDeterminant <[email protected]>2020-11-17 18:47:40 -0500
committerDeterminant <[email protected]>2020-11-17 18:47:40 -0500
commit3bef51eec2299403467e621ae660cef3f9256ac8 (patch)
tree9b72aaa95fb6dffacd8b20164699870a32ab6825 /frozen_deps/Crypto/Signature
parent92b8b8e9628cac41d37226416107adc76b10e01b (diff)
update frozen deps
Diffstat (limited to 'frozen_deps/Crypto/Signature')
-rw-r--r--frozen_deps/Crypto/Signature/PKCS1_PSS.py355
-rw-r--r--frozen_deps/Crypto/Signature/PKCS1_v1_5.py236
-rw-r--r--frozen_deps/Crypto/Signature/__init__.py31
3 files changed, 622 insertions, 0 deletions
diff --git a/frozen_deps/Crypto/Signature/PKCS1_PSS.py b/frozen_deps/Crypto/Signature/PKCS1_PSS.py
new file mode 100644
index 0000000..319851e
--- /dev/null
+++ b/frozen_deps/Crypto/Signature/PKCS1_PSS.py
@@ -0,0 +1,355 @@
+# -*- coding: utf-8 -*-
+#
+# Signature/PKCS1_PSS.py : PKCS#1 PPS
+#
+# ===================================================================
+# The contents of this file are dedicated to the public domain. To
+# the extent that dedication to the public domain is not available,
+# everyone is granted a worldwide, perpetual, royalty-free,
+# non-exclusive license to exercise all rights associated with the
+# contents of this file for any purpose whatsoever.
+# No rights are reserved.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+# ===================================================================
+
+"""RSA digital signature protocol with appendix according to PKCS#1 PSS.
+
+See RFC3447__ or the `original RSA Labs specification`__.
+
+This scheme is more properly called ``RSASSA-PSS``.
+
+For example, a sender may authenticate a message using SHA-1 and PSS like
+this:
+
+ >>> from Crypto.Signature import PKCS1_PSS
+ >>> from Crypto.Hash import SHA
+ >>> from Crypto.PublicKey import RSA
+ >>> from Crypto import Random
+ >>>
+ >>> message = 'To be signed'
+ >>> key = RSA.importKey(open('privkey.der').read())
+ >>> h = SHA.new()
+ >>> h.update(message)
+ >>> signer = PKCS1_PSS.new(key)
+ >>> signature = PKCS1_PSS.sign(key)
+
+At the receiver side, verification can be done like using the public part of
+the RSA key:
+
+ >>> key = RSA.importKey(open('pubkey.der').read())
+ >>> h = SHA.new()
+ >>> h.update(message)
+ >>> verifier = PKCS1_PSS.new(key)
+ >>> if verifier.verify(h, signature):
+ >>> print "The signature is authentic."
+ >>> else:
+ >>> print "The signature is not authentic."
+
+:undocumented: __revision__, __package__
+
+.. __: http://www.ietf.org/rfc/rfc3447.txt
+.. __: http://www.rsa.com/rsalabs/node.asp?id=2125
+"""
+
+# Allow nested scopes in Python 2.1
+# See http://oreilly.com/pub/a/python/2001/04/19/pythonnews.html
+
+
+__revision__ = "$Id$"
+__all__ = [ 'new', 'PSS_SigScheme' ]
+
+from Crypto.Util.py3compat import *
+if sys.version_info[0] == 2 and sys.version_info[1] == 1:
+ from Crypto.Util.py21compat import *
+import Crypto.Util.number
+from Crypto.Util.number import ceil_shift, ceil_div, long_to_bytes
+from Crypto.Util.strxor import strxor
+
+class PSS_SigScheme:
+ """This signature scheme can perform PKCS#1 PSS RSA signature or verification."""
+
+ def __init__(self, key, mgfunc, saltLen):
+ """Initialize this PKCS#1 PSS signature scheme object.
+
+ :Parameters:
+ key : an RSA key object
+ If a private half is given, both signature and verification are possible.
+ If a public half is given, only verification is possible.
+ mgfunc : callable
+ A mask generation function that accepts two parameters: a string to
+ use as seed, and the lenth of the mask to generate, in bytes.
+ saltLen : int
+ Length of the salt, in bytes.
+ """
+ self._key = key
+ self._saltLen = saltLen
+ self._mgfunc = mgfunc
+
+ def can_sign(self):
+ """Return True if this cipher object can be used for signing messages."""
+ return self._key.has_private()
+
+ def sign(self, mhash):
+ """Produce the PKCS#1 PSS signature of a message.
+
+ This function is named ``RSASSA-PSS-SIGN``, and is specified in
+ section 8.1.1 of RFC3447.
+
+ :Parameters:
+ mhash : hash object
+ The hash that was carried out over the message. This is an object
+ belonging to the `Crypto.Hash` module.
+
+ :Return: The PSS signature encoded as a string.
+ :Raise ValueError:
+ If the RSA key length is not sufficiently long to deal with the given
+ hash algorithm.
+ :Raise TypeError:
+ If the RSA key has no private half.
+
+ :attention: Modify the salt length and the mask generation function only
+ if you know what you are doing.
+ The receiver must use the same parameters too.
+ """
+ # TODO: Verify the key is RSA
+
+ randfunc = self._key._randfunc
+
+ # Set defaults for salt length and mask generation function
+ if self._saltLen == None:
+ sLen = mhash.digest_size
+ else:
+ sLen = self._saltLen
+ if self._mgfunc:
+ mgf = self._mgfunc
+ else:
+ mgf = lambda x,y: MGF1(x,y,mhash)
+
+ modBits = Crypto.Util.number.size(self._key.n)
+
+ # See 8.1.1 in RFC3447
+ k = ceil_div(modBits,8) # Convert from bits to bytes
+ # Step 1
+ em = EMSA_PSS_ENCODE(mhash, modBits-1, randfunc, mgf, sLen)
+ # Step 2a (OS2IP) and 2b (RSASP1)
+ m = self._key.decrypt(em)
+ # Step 2c (I2OSP)
+ S = bchr(0x00)*(k-len(m)) + m
+ return S
+
+ def verify(self, mhash, S):
+ """Verify that a certain PKCS#1 PSS signature is authentic.
+
+ This function checks if the party holding the private half of the given
+ RSA key has really signed the message.
+
+ This function is called ``RSASSA-PSS-VERIFY``, and is specified in section
+ 8.1.2 of RFC3447.
+
+ :Parameters:
+ mhash : hash object
+ The hash that was carried out over the message. This is an object
+ belonging to the `Crypto.Hash` module.
+ S : string
+ The signature that needs to be validated.
+
+ :Return: True if verification is correct. False otherwise.
+ """
+ # TODO: Verify the key is RSA
+
+ # Set defaults for salt length and mask generation function
+ if self._saltLen == None:
+ sLen = mhash.digest_size
+ else:
+ sLen = self._saltLen
+ if self._mgfunc:
+ mgf = self._mgfunc
+ else:
+ mgf = lambda x,y: MGF1(x,y,mhash)
+
+ modBits = Crypto.Util.number.size(self._key.n)
+
+ # See 8.1.2 in RFC3447
+ k = ceil_div(modBits,8) # Convert from bits to bytes
+ # Step 1
+ if len(S) != k:
+ return False
+ # Step 2a (O2SIP), 2b (RSAVP1), and partially 2c (I2OSP)
+ # Note that signature must be smaller than the module
+ # but RSA.py won't complain about it.
+ # TODO: Fix RSA object; don't do it here.
+ em = self._key.encrypt(S, 0)[0]
+ # Step 2c
+ emLen = ceil_div(modBits-1,8)
+ em = bchr(0x00)*(emLen-len(em)) + em
+ # Step 3
+ try:
+ result = EMSA_PSS_VERIFY(mhash, em, modBits-1, mgf, sLen)
+ except ValueError:
+ return False
+ # Step 4
+ return result
+
+def MGF1(mgfSeed, maskLen, hash):
+ """Mask Generation Function, described in B.2.1"""
+ T = b("")
+ for counter in range(ceil_div(maskLen, hash.digest_size)):
+ c = long_to_bytes(counter, 4)
+ T = T + hash.new(mgfSeed + c).digest()
+ assert(len(T)>=maskLen)
+ return T[:maskLen]
+
+def EMSA_PSS_ENCODE(mhash, emBits, randFunc, mgf, sLen):
+ """
+ Implement the ``EMSA-PSS-ENCODE`` function, as defined
+ in PKCS#1 v2.1 (RFC3447, 9.1.1).
+
+ The original ``EMSA-PSS-ENCODE`` actually accepts the message ``M`` as input,
+ and hash it internally. Here, we expect that the message has already
+ been hashed instead.
+
+ :Parameters:
+ mhash : hash object
+ The hash object that holds the digest of the message being signed.
+ emBits : int
+ Maximum length of the final encoding, in bits.
+ randFunc : callable
+ An RNG function that accepts as only parameter an int, and returns
+ a string of random bytes, to be used as salt.
+ mgf : callable
+ A mask generation function that accepts two parameters: a string to
+ use as seed, and the lenth of the mask to generate, in bytes.
+ sLen : int
+ Length of the salt, in bytes.
+
+ :Return: An ``emLen`` byte long string that encodes the hash
+ (with ``emLen = \ceil(emBits/8)``).
+
+ :Raise ValueError:
+ When digest or salt length are too big.
+ """
+
+ emLen = ceil_div(emBits,8)
+
+ # Bitmask of digits that fill up
+ lmask = 0
+ for i in range(8*emLen-emBits):
+ lmask = lmask>>1 | 0x80
+
+ # Step 1 and 2 have been already done
+ # Step 3
+ if emLen < mhash.digest_size+sLen+2:
+ raise ValueError("Digest or salt length are too long for given key size.")
+ # Step 4
+ salt = b("")
+ if randFunc and sLen>0:
+ salt = randFunc(sLen)
+ # Step 5 and 6
+ h = mhash.new(bchr(0x00)*8 + mhash.digest() + salt)
+ # Step 7 and 8
+ db = bchr(0x00)*(emLen-sLen-mhash.digest_size-2) + bchr(0x01) + salt
+ # Step 9
+ dbMask = mgf(h.digest(), emLen-mhash.digest_size-1)
+ # Step 10
+ maskedDB = strxor(db,dbMask)
+ # Step 11
+ maskedDB = bchr(bord(maskedDB[0]) & ~lmask) + maskedDB[1:]
+ # Step 12
+ em = maskedDB + h.digest() + bchr(0xBC)
+ return em
+
+def EMSA_PSS_VERIFY(mhash, em, emBits, mgf, sLen):
+ """
+ Implement the ``EMSA-PSS-VERIFY`` function, as defined
+ in PKCS#1 v2.1 (RFC3447, 9.1.2).
+
+ ``EMSA-PSS-VERIFY`` actually accepts the message ``M`` as input,
+ and hash it internally. Here, we expect that the message has already
+ been hashed instead.
+
+ :Parameters:
+ mhash : hash object
+ The hash object that holds the digest of the message to be verified.
+ em : string
+ The signature to verify, therefore proving that the sender really signed
+ the message that was received.
+ emBits : int
+ Length of the final encoding (em), in bits.
+ mgf : callable
+ A mask generation function that accepts two parameters: a string to
+ use as seed, and the lenth of the mask to generate, in bytes.
+ sLen : int
+ Length of the salt, in bytes.
+
+ :Return: 0 if the encoding is consistent, 1 if it is inconsistent.
+
+ :Raise ValueError:
+ When digest or salt length are too big.
+ """
+
+ emLen = ceil_div(emBits,8)
+
+ # Bitmask of digits that fill up
+ lmask = 0
+ for i in range(8*emLen-emBits):
+ lmask = lmask>>1 | 0x80
+
+ # Step 1 and 2 have been already done
+ # Step 3
+ if emLen < mhash.digest_size+sLen+2:
+ return False
+ # Step 4
+ if ord(em[-1:])!=0xBC:
+ return False
+ # Step 5
+ maskedDB = em[:emLen-mhash.digest_size-1]
+ h = em[emLen-mhash.digest_size-1:-1]
+ # Step 6
+ if lmask & bord(em[0]):
+ return False
+ # Step 7
+ dbMask = mgf(h, emLen-mhash.digest_size-1)
+ # Step 8
+ db = strxor(maskedDB, dbMask)
+ # Step 9
+ db = bchr(bord(db[0]) & ~lmask) + db[1:]
+ # Step 10
+ if not db.startswith(bchr(0x00)*(emLen-mhash.digest_size-sLen-2) + bchr(0x01)):
+ return False
+ # Step 11
+ salt = b("")
+ if sLen: salt = db[-sLen:]
+ # Step 12 and 13
+ hp = mhash.new(bchr(0x00)*8 + mhash.digest() + salt).digest()
+ # Step 14
+ if h!=hp:
+ return False
+ return True
+
+def new(key, mgfunc=None, saltLen=None):
+ """Return a signature scheme object `PSS_SigScheme` that
+ can be used to perform PKCS#1 PSS signature or verification.
+
+ :Parameters:
+ key : RSA key object
+ The key to use to sign or verify the message. This is a `Crypto.PublicKey.RSA` object.
+ Signing is only possible if *key* is a private RSA key.
+ mgfunc : callable
+ A mask generation function that accepts two parameters: a string to
+ use as seed, and the lenth of the mask to generate, in bytes.
+ If not specified, the standard MGF1 is used.
+ saltLen : int
+ Length of the salt, in bytes. If not specified, it matches the output
+ size of the hash function.
+
+ """
+ return PSS_SigScheme(key, mgfunc, saltLen)
+
diff --git a/frozen_deps/Crypto/Signature/PKCS1_v1_5.py b/frozen_deps/Crypto/Signature/PKCS1_v1_5.py
new file mode 100644
index 0000000..73ac251
--- /dev/null
+++ b/frozen_deps/Crypto/Signature/PKCS1_v1_5.py
@@ -0,0 +1,236 @@
+# -*- coding: utf-8 -*-
+#
+# Signature/PKCS1-v1_5.py : PKCS#1 v1.5
+#
+# ===================================================================
+# The contents of this file are dedicated to the public domain. To
+# the extent that dedication to the public domain is not available,
+# everyone is granted a worldwide, perpetual, royalty-free,
+# non-exclusive license to exercise all rights associated with the
+# contents of this file for any purpose whatsoever.
+# No rights are reserved.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+# ===================================================================
+
+"""
+RSA digital signature protocol according to PKCS#1 v1.5
+
+See RFC3447__ or the `original RSA Labs specification`__.
+
+This scheme is more properly called ``RSASSA-PKCS1-v1_5``.
+
+For example, a sender may authenticate a message using SHA-1 like
+this:
+
+ >>> from Crypto.Signature import PKCS1_v1_5
+ >>> from Crypto.Hash import SHA
+ >>> from Crypto.PublicKey import RSA
+ >>>
+ >>> message = 'To be signed'
+ >>> key = RSA.importKey(open('privkey.der').read())
+ >>> h = SHA.new(message)
+ >>> signer = PKCS1_v1_5.new(key)
+ >>> signature = signer.sign(h)
+
+At the receiver side, verification can be done using the public part of
+the RSA key:
+
+ >>> key = RSA.importKey(open('pubkey.der').read())
+ >>> h = SHA.new(message)
+ >>> verifier = PKCS1_v1_5.new(key)
+ >>> if verifier.verify(h, signature):
+ >>> print "The signature is authentic."
+ >>> else:
+ >>> print "The signature is not authentic."
+
+:undocumented: __revision__, __package__
+
+.. __: http://www.ietf.org/rfc/rfc3447.txt
+.. __: http://www.rsa.com/rsalabs/node.asp?id=2125
+"""
+
+__revision__ = "$Id$"
+__all__ = [ 'new', 'PKCS115_SigScheme' ]
+
+import Crypto.Util.number
+from Crypto.Util.number import ceil_div
+from Crypto.Util.asn1 import DerSequence, DerNull, DerOctetString
+from Crypto.Util.py3compat import *
+
+class PKCS115_SigScheme:
+ """This signature scheme can perform PKCS#1 v1.5 RSA signature or verification."""
+
+ def __init__(self, key):
+ """Initialize this PKCS#1 v1.5 signature scheme object.
+
+ :Parameters:
+ key : an RSA key object
+ If a private half is given, both signature and verification are possible.
+ If a public half is given, only verification is possible.
+ """
+ self._key = key
+
+ def can_sign(self):
+ """Return True if this cipher object can be used for signing messages."""
+ return self._key.has_private()
+
+ def sign(self, mhash):
+ """Produce the PKCS#1 v1.5 signature of a message.
+
+ This function is named ``RSASSA-PKCS1-V1_5-SIGN``, and is specified in
+ section 8.2.1 of RFC3447.
+
+ :Parameters:
+ mhash : hash object
+ The hash that was carried out over the message. This is an object
+ belonging to the `Crypto.Hash` module.
+
+ :Return: The signature encoded as a string.
+ :Raise ValueError:
+ If the RSA key length is not sufficiently long to deal with the given
+ hash algorithm.
+ :Raise TypeError:
+ If the RSA key has no private half.
+ """
+ # TODO: Verify the key is RSA
+
+ # See 8.2.1 in RFC3447
+ modBits = Crypto.Util.number.size(self._key.n)
+ k = ceil_div(modBits,8) # Convert from bits to bytes
+
+ # Step 1
+ em = EMSA_PKCS1_V1_5_ENCODE(mhash, k)
+ # Step 2a (OS2IP) and 2b (RSASP1)
+ m = self._key.decrypt(em)
+ # Step 2c (I2OSP)
+ S = bchr(0x00)*(k-len(m)) + m
+ return S
+
+ def verify(self, mhash, S):
+ """Verify that a certain PKCS#1 v1.5 signature is authentic.
+
+ This function checks if the party holding the private half of the key
+ really signed the message.
+
+ This function is named ``RSASSA-PKCS1-V1_5-VERIFY``, and is specified in
+ section 8.2.2 of RFC3447.
+
+ :Parameters:
+ mhash : hash object
+ The hash that was carried out over the message. This is an object
+ belonging to the `Crypto.Hash` module.
+ S : string
+ The signature that needs to be validated.
+
+ :Return: True if verification is correct. False otherwise.
+ """
+ # TODO: Verify the key is RSA
+
+ # See 8.2.2 in RFC3447
+ modBits = Crypto.Util.number.size(self._key.n)
+ k = ceil_div(modBits,8) # Convert from bits to bytes
+
+ # Step 1
+ if len(S) != k:
+ return 0
+ # Step 2a (O2SIP) and 2b (RSAVP1)
+ # Note that signature must be smaller than the module
+ # but RSA.py won't complain about it.
+ # TODO: Fix RSA object; don't do it here.
+ m = self._key.encrypt(S, 0)[0]
+ # Step 2c (I2OSP)
+ em1 = bchr(0x00)*(k-len(m)) + m
+ # Step 3
+ try:
+ em2 = EMSA_PKCS1_V1_5_ENCODE(mhash, k)
+ except ValueError:
+ return 0
+ # Step 4
+ # By comparing the full encodings (as opposed to checking each
+ # of its components one at a time) we avoid attacks to the padding
+ # scheme like Bleichenbacher's (see http://www.mail-archive.com/[email protected]/msg06537).
+ #
+ return em1==em2
+
+def EMSA_PKCS1_V1_5_ENCODE(hash, emLen):
+ """
+ Implement the ``EMSA-PKCS1-V1_5-ENCODE`` function, as defined
+ in PKCS#1 v2.1 (RFC3447, 9.2).
+
+ ``EMSA-PKCS1-V1_5-ENCODE`` actually accepts the message ``M`` as input,
+ and hash it internally. Here, we expect that the message has already
+ been hashed instead.
+
+ :Parameters:
+ hash : hash object
+ The hash object that holds the digest of the message being signed.
+ emLen : int
+ The length the final encoding must have, in bytes.
+
+ :attention: the early standard (RFC2313) stated that ``DigestInfo``
+ had to be BER-encoded. This means that old signatures
+ might have length tags in indefinite form, which
+ is not supported in DER. Such encoding cannot be
+ reproduced by this function.
+
+ :attention: the same standard defined ``DigestAlgorithm`` to be
+ of ``AlgorithmIdentifier`` type, where the PARAMETERS
+ item is optional. Encodings for ``MD2/4/5`` without
+ ``PARAMETERS`` cannot be reproduced by this function.
+
+ :Return: An ``emLen`` byte long string that encodes the hash.
+ """
+
+ # First, build the ASN.1 DER object DigestInfo:
+ #
+ # DigestInfo ::= SEQUENCE {
+ # digestAlgorithm AlgorithmIdentifier,
+ # digest OCTET STRING
+ # }
+ #
+ # where digestAlgorithm identifies the hash function and shall be an
+ # algorithm ID with an OID in the set PKCS1-v1-5DigestAlgorithms.
+ #
+ # PKCS1-v1-5DigestAlgorithms ALGORITHM-IDENTIFIER ::= {
+ # { OID id-md2 PARAMETERS NULL }|
+ # { OID id-md5 PARAMETERS NULL }|
+ # { OID id-sha1 PARAMETERS NULL }|
+ # { OID id-sha256 PARAMETERS NULL }|
+ # { OID id-sha384 PARAMETERS NULL }|
+ # { OID id-sha512 PARAMETERS NULL }
+ # }
+ #
+ digestAlgo = DerSequence([hash.oid, DerNull().encode()])
+ digest = DerOctetString(hash.digest())
+ digestInfo = DerSequence([
+ digestAlgo.encode(),
+ digest.encode()
+ ]).encode()
+
+ # We need at least 11 bytes for the remaining data: 3 fixed bytes and
+ # at least 8 bytes of padding).
+ if emLen<len(digestInfo)+11:
+ raise ValueError("Selected hash algorith has a too long digest (%d bytes)." % len(digest))
+ PS = bchr(0xFF) * (emLen - len(digestInfo) - 3)
+ return b("\x00\x01") + PS + bchr(0x00) + digestInfo
+
+def new(key):
+ """Return a signature scheme object `PKCS115_SigScheme` that
+ can be used to perform PKCS#1 v1.5 signature or verification.
+
+ :Parameters:
+ key : RSA key object
+ The key to use to sign or verify the message. This is a `Crypto.PublicKey.RSA` object.
+ Signing is only possible if *key* is a private RSA key.
+
+ """
+ return PKCS115_SigScheme(key)
+
diff --git a/frozen_deps/Crypto/Signature/__init__.py b/frozen_deps/Crypto/Signature/__init__.py
new file mode 100644
index 0000000..ed523b4
--- /dev/null
+++ b/frozen_deps/Crypto/Signature/__init__.py
@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+#
+# ===================================================================
+# The contents of this file are dedicated to the public domain. To
+# the extent that dedication to the public domain is not available,
+# everyone is granted a worldwide, perpetual, royalty-free,
+# non-exclusive license to exercise all rights associated with the
+# contents of this file for any purpose whatsoever.
+# No rights are reserved.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+# ===================================================================
+
+"""Digital signature protocols
+
+A collection of standardized protocols to carry out digital signatures.
+
+:undocumented: __revision__, __package__
+"""
+
+__all__ = [ 'PKCS1_v1_5', 'PKCS1_PSS' ]
+__revision__ = "$Id$"
+
+