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Diffstat (limited to 'frozen_deps/Crypto/Util/asn1.py')
| -rw-r--r-- | frozen_deps/Crypto/Util/asn1.py | 286 |
1 files changed, 0 insertions, 286 deletions
diff --git a/frozen_deps/Crypto/Util/asn1.py b/frozen_deps/Crypto/Util/asn1.py deleted file mode 100644 index 9a97d97..0000000 --- a/frozen_deps/Crypto/Util/asn1.py +++ /dev/null @@ -1,286 +0,0 @@ -# -*- coding: ascii -*- -# -# Util/asn1.py : Minimal support for ASN.1 DER binary encoding. -# -# =================================================================== -# 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. -# =================================================================== - -from Crypto.Util.number import long_to_bytes, bytes_to_long -import sys -from Crypto.Util.py3compat import * - -__all__ = [ 'DerObject', 'DerInteger', 'DerOctetString', 'DerNull', 'DerSequence', 'DerObjectId' ] - -class DerObject: - """Base class for defining a single DER object. - - Instantiate this class ONLY when you have to decode a DER element. - """ - - # Known TAG types - typeTags = { 'SEQUENCE': 0x30, 'BIT STRING': 0x03, 'INTEGER': 0x02, - 'OCTET STRING': 0x04, 'NULL': 0x05, 'OBJECT IDENTIFIER': 0x06 } - - def __init__(self, ASN1Type=None, payload=b('')): - """Initialize the DER object according to a specific type. - - The ASN.1 type is either specified as the ASN.1 string (e.g. - 'SEQUENCE'), directly with its numerical tag or with no tag - at all (None).""" - if isInt(ASN1Type) or ASN1Type is None: - self.typeTag = ASN1Type - else: - if len(ASN1Type)==1: - self.typeTag = ord(ASN1Type) - else: - self.typeTag = self.typeTags.get(ASN1Type) - self.payload = payload - - def isType(self, ASN1Type): - return self.typeTags[ASN1Type]==self.typeTag - - def _lengthOctets(self, payloadLen): - """Return a byte string that encodes the given payload length (in - bytes) in a format suitable for a DER length tag (L). - """ - if payloadLen>127: - encoding = long_to_bytes(payloadLen) - return bchr(len(encoding)+128) + encoding - return bchr(payloadLen) - - def encode(self): - """Return a complete DER element, fully encoded as a TLV.""" - return bchr(self.typeTag) + self._lengthOctets(len(self.payload)) + self.payload - - def _decodeLen(self, idx, der): - """Given a (part of a) DER element, and an index to the first byte of - a DER length tag (L), return a tuple with the payload size, - and the index of the first byte of the such payload (V). - - Raises a ValueError exception if the DER length is invalid. - Raises an IndexError exception if the DER element is too short. - """ - length = bord(der[idx]) - if length<=127: - return (length,idx+1) - payloadLength = bytes_to_long(der[idx+1:idx+1+(length & 0x7F)]) - if payloadLength<=127: - raise ValueError("Not a DER length tag.") - return (payloadLength, idx+1+(length & 0x7F)) - - def decode(self, derEle, noLeftOvers=0): - """Decode a complete DER element, and re-initializes this - object with it. - - @param derEle A complete DER element. It must start with a DER T - tag. - @param noLeftOvers Indicate whether it is acceptable to complete the - parsing of the DER element and find that not all - bytes in derEle have been used. - @return Index of the first unused byte in the given DER element. - - Raises a ValueError exception in case of parsing errors. - Raises an IndexError exception if the DER element is too short. - """ - try: - self.typeTag = bord(derEle[0]) - if (self.typeTag & 0x1F)==0x1F: - raise ValueError("Unsupported DER tag") - (length,idx) = self._decodeLen(1, derEle) - if noLeftOvers and len(derEle) != (idx+length): - raise ValueError("Not a DER structure") - self.payload = derEle[idx:idx+length] - except IndexError: - raise ValueError("Not a valid DER SEQUENCE.") - return idx+length - -class DerInteger(DerObject): - def __init__(self, value = 0): - """Class to model an INTEGER DER element. - - Limitation: only non-negative values are supported. - """ - DerObject.__init__(self, 'INTEGER') - self.value = value - - def encode(self): - """Return a complete INTEGER DER element, fully encoded as a TLV.""" - self.payload = long_to_bytes(self.value) - if bord(self.payload[0])>127: - self.payload = bchr(0x00) + self.payload - return DerObject.encode(self) - - def decode(self, derEle, noLeftOvers=0): - """Decode a complete INTEGER DER element, and re-initializes this - object with it. - - @param derEle A complete INTEGER DER element. It must start with a DER - INTEGER tag. - @param noLeftOvers Indicate whether it is acceptable to complete the - parsing of the DER element and find that not all - bytes in derEle have been used. - @return Index of the first unused byte in the given DER element. - - Raises a ValueError exception if the DER element is not a - valid non-negative INTEGER. - Raises an IndexError exception if the DER element is too short. - """ - tlvLength = DerObject.decode(self, derEle, noLeftOvers) - if self.typeTag!=self.typeTags['INTEGER']: - raise ValueError ("Not a DER INTEGER.") - if bord(self.payload[0])>127: - raise ValueError ("Negative INTEGER.") - self.value = bytes_to_long(self.payload) - return tlvLength - -class DerSequence(DerObject): - """Class to model a SEQUENCE DER element. - - This object behave like a dynamic Python sequence. - Sub-elements that are INTEGERs, look like Python integers. - Any other sub-element is a binary string encoded as the complete DER - sub-element (TLV). - """ - - def __init__(self, startSeq=None): - """Initialize the SEQUENCE DER object. Always empty - initially.""" - DerObject.__init__(self, 'SEQUENCE') - if startSeq==None: - self._seq = [] - else: - self._seq = startSeq - - ## A few methods to make it behave like a python sequence - - def __delitem__(self, n): - del self._seq[n] - def __getitem__(self, n): - return self._seq[n] - def __setitem__(self, key, value): - self._seq[key] = value - def __setslice__(self,i,j,sequence): - self._seq[i:j] = sequence - def __delslice__(self,i,j): - del self._seq[i:j] - def __getslice__(self, i, j): - return self._seq[max(0, i):max(0, j)] - def __len__(self): - return len(self._seq) - def append(self, item): - return self._seq.append(item) - - def hasInts(self): - """Return the number of items in this sequence that are numbers.""" - return len(list(filter(isInt, self._seq))) - - def hasOnlyInts(self): - """Return True if all items in this sequence are numbers.""" - return self._seq and self.hasInts()==len(self._seq) - - def encode(self): - """Return the DER encoding for the ASN.1 SEQUENCE, containing - the non-negative integers and longs added to this object. - - Limitation: Raises a ValueError exception if it some elements - in the sequence are neither Python integers nor complete DER INTEGERs. - """ - self.payload = b('') - for item in self._seq: - try: - self.payload += item - except: - try: - self.payload += DerInteger(item).encode() - except: - raise ValueError("Trying to DER encode an unknown object") - return DerObject.encode(self) - - def decode(self, derEle, noLeftOvers=0): - """Decode a complete SEQUENCE DER element, and re-initializes this - object with it. - - @param derEle A complete SEQUENCE DER element. It must start with a DER - SEQUENCE tag. - @param noLeftOvers Indicate whether it is acceptable to complete the - parsing of the DER element and find that not all - bytes in derEle have been used. - @return Index of the first unused byte in the given DER element. - - DER INTEGERs are decoded into Python integers. Any other DER - element is not decoded. Its validity is not checked. - - Raises a ValueError exception if the DER element is not a - valid DER SEQUENCE. - Raises an IndexError exception if the DER element is too short. - """ - - self._seq = [] - try: - tlvLength = DerObject.decode(self, derEle, noLeftOvers) - if self.typeTag!=self.typeTags['SEQUENCE']: - raise ValueError("Not a DER SEQUENCE.") - # Scan one TLV at once - idx = 0 - while idx<len(self.payload): - typeTag = bord(self.payload[idx]) - if typeTag==self.typeTags['INTEGER']: - newInteger = DerInteger() - idx += newInteger.decode(self.payload[idx:]) - self._seq.append(newInteger.value) - else: - itemLen,itemIdx = self._decodeLen(idx+1,self.payload) - self._seq.append(self.payload[idx:itemIdx+itemLen]) - idx = itemIdx + itemLen - except IndexError: - raise ValueError("Not a valid DER SEQUENCE.") - return tlvLength - -class DerOctetString(DerObject): - def __init__(self, value = b('')): - DerObject.__init__(self, 'OCTET STRING') - self.payload = value - - def decode(self, derEle, noLeftOvers=0): - p = DerObject.decode(derEle, noLeftOvers) - if not self.isType("OCTET STRING"): - raise ValueError("Not a valid OCTET STRING.") - return p - -class DerNull(DerObject): - def __init__(self): - DerObject.__init__(self, 'NULL') - -class DerObjectId(DerObject): - def __init__(self): - DerObject.__init__(self, 'OBJECT IDENTIFIER') - - def decode(self, derEle, noLeftOvers=0): - p = DerObject.decode(derEle, noLeftOvers) - if not self.isType("OBJECT IDENTIFIER"): - raise ValueError("Not a valid OBJECT IDENTIFIER.") - return p - -def isInt(x): - test = 0 - try: - test += x - except TypeError: - return 0 - return 1 - |