# This file is dual licensed under the terms of the Apache License, Version # 2.0, and the BSD License. See the LICENSE file in the root of this repository # for complete details. from __future__ import absolute_import, division, print_function import binascii import collections import math import re from contextlib import contextmanager import pytest import six from cryptography.exceptions import UnsupportedAlgorithm import cryptography_vectors HashVector = collections.namedtuple("HashVector", ["message", "digest"]) KeyedHashVector = collections.namedtuple( "KeyedHashVector", ["message", "digest", "key"] ) def select_backends(names, backend_list): if names is None: return backend_list split_names = [x.strip() for x in names.split(',')] selected_backends = [] for backend in backend_list: if backend.name in split_names: selected_backends.append(backend) if len(selected_backends) > 0: return selected_backends else: raise ValueError( "No backend selected. Tried to select: {0}".format(split_names) ) def skip_if_empty(backend_list, required_interfaces): if not backend_list: pytest.skip( "No backends provided supply the interface: {0}".format( ", ".join(iface.__name__ for iface in required_interfaces) ) ) def check_backend_support(item): supported = item.keywords.get("supported") if supported and "backend" in item.funcargs: for mark in supported: if not mark.kwargs["only_if"](item.funcargs["backend"]): pytest.skip("{0} ({1})".format( mark.kwargs["skip_message"], item.funcargs["backend"] )) elif supported: raise ValueError("This mark is only available on methods that take a " "backend") @contextmanager def raises_unsupported_algorithm(reason): with pytest.raises(UnsupportedAlgorithm) as exc_info: yield exc_info assert exc_info.value._reason is reason def load_vectors_from_file(filename, loader, mode="r"): with cryptography_vectors.open_vector_file(filename, mode) as vector_file: return loader(vector_file) def load_nist_vectors(vector_data): test_data = None data = [] for line in vector_data: line = line.strip() # Blank lines, comments, and section headers are ignored if not line or line.startswith("#") or (line.startswith("[") and line.endswith("]")): continue if line.strip() == "FAIL": test_data["fail"] = True continue # Build our data using a simple Key = Value format name, value = [c.strip() for c in line.split("=")] # Some tests (PBKDF2) contain \0, which should be interpreted as a # null character rather than literal. value = value.replace("\\0", "\0") # COUNT is a special token that indicates a new block of data if name.upper() == "COUNT": test_data = {} data.append(test_data) continue # For all other tokens we simply want the name, value stored in # the dictionary else: test_data[name.lower()] = value.encode("ascii") return data def load_cryptrec_vectors(vector_data): cryptrec_list = [] for line in vector_data: line = line.strip() # Blank lines and comments are ignored if not line or line.startswith("#"): continue if line.startswith("K"): key = line.split(" : ")[1].replace(" ", "").encode("ascii") elif line.startswith("P"): pt = line.split(" : ")[1].replace(" ", "").encode("ascii") elif line.startswith("C"): ct = line.split(" : ")[1].replace(" ", "").encode("ascii") # after a C is found the K+P+C tuple is complete # there are many P+C pairs for each K cryptrec_list.append({ "key": key, "plaintext": pt, "ciphertext": ct }) else: raise ValueError("Invalid line in file '{}'".format(line)) return cryptrec_list def load_hash_vectors(vector_data): vectors = [] key = None msg = None md = None for line in vector_data: line = line.strip() if not line or line.startswith("#") or line.startswith("["): continue if line.startswith("Len"): length = int(line.split(" = ")[1]) elif line.startswith("Key"): # HMAC vectors contain a key attribute. Hash vectors do not. key = line.split(" = ")[1].encode("ascii") elif line.startswith("Msg"): # In the NIST vectors they have chosen to represent an empty # string as hex 00, which is of course not actually an empty # string. So we parse the provided length and catch this edge case. msg = line.split(" = ")[1].encode("ascii") if length > 0 else b"" elif line.startswith("MD"): md = line.split(" = ")[1] # after MD is found the Msg+MD (+ potential key) tuple is complete if key is not None: vectors.append(KeyedHashVector(msg, md, key)) key = None msg = None md = None else: vectors.append(HashVector(msg, md)) msg = None md = None else: raise ValueError("Unknown line in hash vector") return vectors def load_pkcs1_vectors(vector_data): """ Loads data out of RSA PKCS #1 vector files. """ private_key_vector = None public_key_vector = None attr = None key = None example_vector = None examples = [] vectors = [] for line in vector_data: if ( line.startswith("# PSS Example") or line.startswith("# OAEP Example") or line.startswith("# PKCS#1 v1.5") ): if example_vector: for key, value in six.iteritems(example_vector): hex_str = "".join(value).replace(" ", "").encode("ascii") example_vector[key] = hex_str examples.append(example_vector) attr = None example_vector = collections.defaultdict(list) if line.startswith("# Message"): attr = "message" continue elif line.startswith("# Salt"): attr = "salt" continue elif line.startswith("# Seed"): attr = "seed" continue elif line.startswith("# Signature"): attr = "signature" continue elif line.startswith("# Encryption"): attr = "encryption" continue elif ( example_vector and line.startswith("# =============================================") ): for key, value in six.iteritems(example_vector): hex_str = "".join(value).replace(" ", "").encode("ascii") example_vector[key] = hex_str examples.append(example_vector) example_vector = None attr = None elif example_vector and line.startswith("#"): continue else: if attr is not None and example_vector is not None: example_vector[attr].append(line.strip()) continue if ( line.startswith("# Example") or line.startswith("# =============================================") ): if key: assert private_key_vector assert public_key_vector for key, value in six.iteritems(public_key_vector): hex_str = "".join(value).replace(" ", "") public_key_vector[key] = int(hex_str, 16) for key, value in six.iteritems(private_key_vector): hex_str = "".join(value).replace(" ", "") private_key_vector[key] = int(hex_str, 16) private_key_vector["examples"] = examples examples = [] assert ( private_key_vector['public_exponent'] == public_key_vector['public_exponent'] ) assert ( private_key_vector['modulus'] == public_key_vector['modulus'] ) vectors.append( (private_key_vector, public_key_vector) ) public_key_vector = collections.defaultdict(list) private_key_vector = collections.defaultdict(list) key = None attr = None if private_key_vector is None or public_key_vector is None: continue if line.startswith("# Private key"): key = private_key_vector elif line.startswith("# Public key"): key = public_key_vector elif line.startswith("# Modulus:"): attr = "modulus" elif line.startswith("# Public exponent:"): attr = "public_exponent" elif line.startswith("# Exponent:"): if key is public_key_vector: attr = "public_exponent" else: assert key is private_key_vector attr = "private_exponent" elif line.startswith("# Prime 1:"): attr = "p" elif line.startswith("# Prime 2:"): attr = "q" elif line.startswith("# Prime exponent 1:"): attr = "dmp1" elif line.startswith("# Prime exponent 2:"): attr = "dmq1" elif line.startswith("# Coefficient:"): attr = "iqmp" elif line.startswith("#"): attr = None else: if key is not None and attr is not None: key[attr].append(line.strip()) return vectors def load_rsa_nist_vectors(vector_data): test_data = None p = None salt_length = None data = [] for line in vector_data: line = line.strip() # Blank lines and section headers are ignored if not line or line.startswith("["): continue if line.startswith("# Salt len:"): salt_length = int(line.split(":")[1].strip()) continue elif line.startswith("#"): continue # Build our data using a simple Key = Value format name, value = [c.strip() for c in line.split("=")] if name == "n": n = int(value, 16) elif name == "e" and p is None: e = int(value, 16) elif name == "p": p = int(value, 16) elif name == "q": q = int(value, 16) elif name == "SHAAlg": if p is None: test_data = { "modulus": n, "public_exponent": e, "salt_length": salt_length, "algorithm": value, "fail": False } else: test_data = { "modulus": n, "p": p, "q": q, "algorithm": value } if salt_length is not None: test_data["salt_length"] = salt_length data.append(test_data) elif name == "e" and p is not None: test_data["public_exponent"] = int(value, 16) elif name == "d": test_data["private_exponent"] = int(value, 16) elif name == "Result": test_data["fail"] = value.startswith("F") # For all other tokens we simply want the name, value stored in # the dictionary else: test_data[name.lower()] = value.encode("ascii") return data def load_fips_dsa_key_pair_vectors(vector_data): """ Loads data out of the FIPS DSA KeyPair vector files. """ vectors = [] # When reading_key_data is set to True it tells the loader to continue # constructing dictionaries. We set reading_key_data to False during the # blocks of the vectors of N=224 because we don't support it. reading_key_data = True for line in vector_data: line = line.strip() if not line or line.startswith("#"): continue elif line.startswith("[mod = L=1024"): continue elif line.startswith("[mod = L=2048, N=224"): reading_key_data = False continue elif line.startswith("[mod = L=2048, N=256"): reading_key_data = True continue elif line.startswith("[mod = L=3072"): continue if reading_key_data: if line.startswith("P"): vectors.append({'p': int(line.split("=")[1], 16)}) elif line.startswith("Q"): vectors[-1]['q'] = int(line.split("=")[1], 16) elif line.startswith("G"): vectors[-1]['g'] = int(line.split("=")[1], 16) elif line.startswith("X") and 'x' not in vectors[-1]: vectors[-1]['x'] = int(line.split("=")[1], 16) elif line.startswith("X") and 'x' in vectors[-1]: vectors.append({'p': vectors[-1]['p'], 'q': vectors[-1]['q'], 'g': vectors[-1]['g'], 'x': int(line.split("=")[1], 16) }) elif line.startswith("Y"): vectors[-1]['y'] = int(line.split("=")[1], 16) return vectors def load_fips_dsa_sig_vectors(vector_data): """ Loads data out of the FIPS DSA SigVer vector files. """ vectors = [] sha_regex = re.compile( r"\[mod = L=...., N=..., SHA-(?P1|224|256|384|512)\]" ) # When reading_key_data is set to True it tells the loader to continue # constructing dictionaries. We set reading_key_data to False during the # blocks of the vectors of N=224 because we don't support it. reading_key_data = True for line in vector_data: line = line.strip() if not line or line.startswith("#"): continue sha_match = sha_regex.match(line) if sha_match: digest_algorithm = "SHA-{0}".format(sha_match.group("sha")) if line.startswith("[mod = L=2048, N=224"): reading_key_data = False continue elif line.startswith("[mod = L=2048, N=256"): reading_key_data = True continue if not reading_key_data or line.startswith("[mod"): continue name, value = [c.strip() for c in line.split("=")] if name == "P": vectors.append({'p': int(value, 16), 'digest_algorithm': digest_algorithm}) elif name == "Q": vectors[-1]['q'] = int(value, 16) elif name == "G": vectors[-1]['g'] = int(value, 16) elif name == "Msg" and 'msg' not in vectors[-1]: hexmsg = value.strip().encode("ascii") vectors[-1]['msg'] = binascii.unhexlify(hexmsg) elif name == "Msg" and 'msg' in vectors[-1]: hexmsg = value.strip().encode("ascii") vectors.append({'p': vectors[-1]['p'], 'q': vectors[-1]['q'], 'g': vectors[-1]['g'], 'digest_algorithm': vectors[-1]['digest_algorithm'], 'msg': binascii.unhexlify(hexmsg)}) elif name == "X": vectors[-1]['x'] = int(value, 16) elif name == "Y": vectors[-1]['y'] = int(value, 16) elif name == "R": vectors[-1]['r'] = int(value, 16) elif name == "S": vectors[-1]['s'] = int(value, 16) elif name == "Result": vectors[-1]['result'] = value.split("(")[0].strip() return vectors # http://tools.ietf.org/html/rfc4492#appendix-A _ECDSA_CURVE_NAMES = { "P-192": "secp192r1", "P-224": "secp224r1", "P-256": "secp256r1", "P-384": "secp384r1", "P-521": "secp521r1", "K-163": "sect163k1", "K-233": "sect233k1", "K-256": "secp256k1", "K-283": "sect283k1", "K-409": "sect409k1", "K-571": "sect571k1", "B-163": "sect163r2", "B-233": "sect233r1", "B-283": "sect283r1", "B-409": "sect409r1", "B-571": "sect571r1", } def load_fips_ecdsa_key_pair_vectors(vector_data): """ Loads data out of the FIPS ECDSA KeyPair vector files. """ vectors = [] key_data = None for line in vector_data: line = line.strip() if not line or line.startswith("#"): continue if line[1:-1] in _ECDSA_CURVE_NAMES: curve_name = _ECDSA_CURVE_NAMES[line[1:-1]] elif line.startswith("d = "): if key_data is not None: vectors.append(key_data) key_data = { "curve": curve_name, "d": int(line.split("=")[1], 16) } elif key_data is not None: if line.startswith("Qx = "): key_data["x"] = int(line.split("=")[1], 16) elif line.startswith("Qy = "): key_data["y"] = int(line.split("=")[1], 16) assert key_data is not None vectors.append(key_data) return vectors def load_fips_ecdsa_signing_vectors(vector_data): """ Loads data out of the FIPS ECDSA SigGen vector files. """ vectors = [] curve_rx = re.compile( r"\[(?P[PKB]-[0-9]{3}),SHA-(?P1|224|256|384|512)\]" ) data = None for line in vector_data: line = line.strip() curve_match = curve_rx.match(line) if curve_match: curve_name = _ECDSA_CURVE_NAMES[curve_match.group("curve")] digest_name = "SHA-{0}".format(curve_match.group("sha")) elif line.startswith("Msg = "): if data is not None: vectors.append(data) hexmsg = line.split("=")[1].strip().encode("ascii") data = { "curve": curve_name, "digest_algorithm": digest_name, "message": binascii.unhexlify(hexmsg) } elif data is not None: if line.startswith("Qx = "): data["x"] = int(line.split("=")[1], 16) elif line.startswith("Qy = "): data["y"] = int(line.split("=")[1], 16) elif line.startswith("R = "): data["r"] = int(line.split("=")[1], 16) elif line.startswith("S = "): data["s"] = int(line.split("=")[1], 16) elif line.startswith("d = "): data["d"] = int(line.split("=")[1], 16) elif line.startswith("Result = "): data["fail"] = line.split("=")[1].strip()[0] == "F" assert data is not None vectors.append(data) return vectors def load_kasvs_dh_vectors(vector_data): """ Loads data out of the KASVS key exchange vector data """ result_rx = re.compile(r"([FP]) \(([0-9]+) -") vectors = [] data = { "fail_z": False, "fail_agree": False } for line in vector_data: line = line.strip() if not line or line.startswith("#"): continue if line.startswith("P = "): data["p"] = int(line.split("=")[1], 16) elif line.startswith("Q = "): data["q"] = int(line.split("=")[1], 16) elif line.startswith("G = "): data["g"] = int(line.split("=")[1], 16) elif line.startswith("Z = "): z_hex = line.split("=")[1].strip().encode("ascii") data["z"] = binascii.unhexlify(z_hex) elif line.startswith("XstatCAVS = "): data["x1"] = int(line.split("=")[1], 16) elif line.startswith("YstatCAVS = "): data["y1"] = int(line.split("=")[1], 16) elif line.startswith("XstatIUT = "): data["x2"] = int(line.split("=")[1], 16) elif line.startswith("YstatIUT = "): data["y2"] = int(line.split("=")[1], 16) elif line.startswith("Result = "): result_str = line.split("=")[1].strip() match = result_rx.match(result_str) if match.group(1) == "F": if int(match.group(2)) in (5, 10): data["fail_z"] = True else: data["fail_agree"] = True vectors.append(data) data = { "p": data["p"], "q": data["q"], "g": data["g"], "fail_z": False, "fail_agree": False } return vectors def load_kasvs_ecdh_vectors(vector_data): """ Loads data out of the KASVS key exchange vector data """ curve_name_map = { "P-192": "secp192r1", "P-224": "secp224r1", "P-256": "secp256r1", "P-384": "secp384r1", "P-521": "secp521r1", } result_rx = re.compile(r"([FP]) \(([0-9]+) -") tags = [] sets = {} vectors = [] # find info in header for line in vector_data: line = line.strip() if line.startswith("#"): parm = line.split("Parameter set(s) supported:") if len(parm) == 2: names = parm[1].strip().split() for n in names: tags.append("[%s]" % n) break # Sets Metadata tag = None curve = None for line in vector_data: line = line.strip() if not line or line.startswith("#"): continue if line in tags: tag = line curve = None elif line.startswith("[Curve selected:"): curve = curve_name_map[line.split(':')[1].strip()[:-1]] if tag is not None and curve is not None: sets[tag.strip("[]")] = curve tag = None if len(tags) == len(sets): break # Data data = { "CAVS": {}, "IUT": {}, } tag = None for line in vector_data: line = line.strip() if not line or line.startswith("#"): continue if line.startswith("["): tag = line.split()[0][1:] elif line.startswith("COUNT = "): data["COUNT"] = int(line.split("=")[1]) elif line.startswith("dsCAVS = "): data["CAVS"]["d"] = int(line.split("=")[1], 16) elif line.startswith("QsCAVSx = "): data["CAVS"]["x"] = int(line.split("=")[1], 16) elif line.startswith("QsCAVSy = "): data["CAVS"]["y"] = int(line.split("=")[1], 16) elif line.startswith("dsIUT = "): data["IUT"]["d"] = int(line.split("=")[1], 16) elif line.startswith("QsIUTx = "): data["IUT"]["x"] = int(line.split("=")[1], 16) elif line.startswith("QsIUTy = "): data["IUT"]["y"] = int(line.split("=")[1], 16) elif line.startswith("OI = "): data["OI"] = int(line.split("=")[1], 16) elif line.startswith("Z = "): data["Z"] = int(line.split("=")[1], 16) elif line.startswith("DKM = "): data["DKM"] = int(line.split("=")[1], 16) elif line.startswith("Result = "): result_str = line.split("=")[1].strip() match = result_rx.match(result_str) if match.group(1) == "F": data["fail"] = True else: data["fail"] = False data["errno"] = int(match.group(2)) data["curve"] = sets[tag] vectors.append(data) data = { "CAVS": {}, "IUT": {}, } return vectors def load_x963_vectors(vector_data): """ Loads data out of the X9.63 vector data """ vectors = [] # Sets Metadata hashname = None vector = {} for line in vector_data: line = line.strip() if line.startswith("[SHA"): hashname = line[1:-1] shared_secret_len = 0 shared_info_len = 0 key_data_len = 0 elif line.startswith("[shared secret length"): shared_secret_len = int(line[1:-1].split("=")[1].strip()) elif line.startswith("[SharedInfo length"): shared_info_len = int(line[1:-1].split("=")[1].strip()) elif line.startswith("[key data length"): key_data_len = int(line[1:-1].split("=")[1].strip()) elif line.startswith("COUNT"): count = int(line.split("=")[1].strip()) vector["hash"] = hashname vector["count"] = count vector["shared_secret_length"] = shared_secret_len vector["sharedinfo_length"] = shared_info_len vector["key_data_length"] = key_data_len elif line.startswith("Z"): vector["Z"] = line.split("=")[1].strip() assert math.ceil(shared_secret_len / 8) * 2 == len(vector["Z"]) elif line.startswith("SharedInfo"): if shared_info_len != 0: vector["sharedinfo"] = line.split("=")[1].strip() silen = len(vector["sharedinfo"]) assert math.ceil(shared_info_len / 8) * 2 == silen elif line.startswith("key_data"): vector["key_data"] = line.split("=")[1].strip() assert math.ceil(key_data_len / 8) * 2 == len(vector["key_data"]) vectors.append(vector) vector = {} return vectors def load_nist_kbkdf_vectors(vector_data): """ Load NIST SP 800-108 KDF Vectors """ vectors = [] test_data = None tag = {} for line in vector_data: line = line.strip() if not line or line.startswith("#"): continue if line.startswith("[") and line.endswith("]"): tag_data = line[1:-1] name, value = [c.strip() for c in tag_data.split("=")] if value.endswith('_BITS'): value = int(value.split('_')[0]) tag.update({name.lower(): value}) continue tag.update({name.lower(): value.lower()}) elif line.startswith("COUNT="): test_data = dict() test_data.update(tag) vectors.append(test_data) elif line.startswith("L"): name, value = [c.strip() for c in line.split("=")] test_data[name.lower()] = int(value) else: name, value = [c.strip() for c in line.split("=")] test_data[name.lower()] = value.encode("ascii") return vectors ht: bold } /* Keyword.Type */ .highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */ .highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */ .highlight .na { color: #336699 } /* Name.Attribute */ .highlight .nb { color: #003388 } /* Name.Builtin */ .highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */ .highlight .no { color: #003366; font-weight: bold } /* Name.Constant */ .highlight .nd { color: #555555 } /* Name.Decorator */ .highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */ .highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */ .highlight .nl { color: #336699; font-style: italic } /* Name.Label */ .highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */ .highlight .py { color: #336699; font-weight: bold } /* Name.Property */ .highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */ .highlight .nv { color: #336699 } /* Name.Variable */ .highlight .ow { color: #008800 } /* Operator.Word */ .highlight .w { color: #bbbbbb } /* Text.Whitespace */ .highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */ .highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */ .highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */ .highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */ .highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */ .highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */ .highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */ .highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */ .highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */ .highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */ .highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */ .highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */ .highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */ .highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */ .highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */ .highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */ .highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */ .highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */ .highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */ .highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */ .highlight .vc { color: #336699 } /* Name.Variable.Class */ .highlight .vg { color: #dd7700 } /* Name.Variable.Global */ .highlight .vi { color: #3333bb } /* Name.Variable.Instance */ .highlight .vm { color: #336699 } /* Name.Variable.Magic */ .highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
The GNU General Public License, Version 3, 29 June 2007 (GPLv3)
===============================================================

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> Free Software Foundation, Inc.
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change the software. The systematic pattern of such abuse occurs in the area of
products for individuals to use, which is precisely where it is most
unacceptable. Therefore, we have designed this version of the GPL to prohibit
the practice for those products. If such problems arise substantially in other
domains, we stand ready to extend this provision to those domains in future
versions of the GPL, as needed to protect the freedom of users.

Finally, every program is threatened constantly by software patents. States
should not allow patents to restrict development and use of software on
general-purpose computers, but in those that do, we wish to avoid the special
danger that patents applied to a free program could make it effectively
proprietary. To prevent this, the GPL assures that patents cannot be used to
render the program non-free.

The precise terms and conditions for copying, distribution and modification
follow.


TERMS AND CONDITIONS
--------------------


### 0. Definitions.

"This License refers to version 3 of the GNU General Public License.

"Copyright" also means copyright-like laws that apply to other kinds of works,
such as semiconductor masks.

"The Program" refers to any copyrightable work licensed under this License. Each
licensee is addressed as "you". "Licensees" and "recipients" may be individuals
or organizations.

To "modify" a work means to copy from or adapt all or part of the work in a
fashion requiring copyright permission, other than the making of an exact copy.
The resulting work is called a "modified version" of the earlier work or a work
"based on" the earlier work.

A "covered work" means either the unmodified Program or a work based on the
Program.

To "propagate" a work means to do anything with it that, without permission,
would make you directly or secondarily liable for infringement under applicable
copyright law, except executing it on a computer or modifying a private copy.
Propagation includes copying, distribution (with or without modification),
making available to the public, and in some countries other activities as well.

To "convey" a work means any kind of propagation that enables other parties to
make or receive copies. Mere interaction with a user through a computer network,
with no transfer of a copy, is not conveying.

An interactive user interface displays "Appropriate Legal Notices" to the extent
that it includes a convenient and prominently visible feature that (1) displays
an appropriate copyright notice, and (2) tells the user that there is no
warranty for the work (except to the extent that warranties are provided), that
licensees may convey the work under this License, and how to view a copy of this
License. If the interface presents a list of user commands or options, such as a
menu, a prominent item in the list meets this criterion.


### 1. Source Code.

The "source code" for a work means the preferred form of the work for making
modifications to it. "Object code" means any non-source form of a work.

A "Standard Interface" means an interface that either is an official standard
defined by a recognized standards body, or, in the case of interfaces specified
for a particular programming language, one that is widely used among developers
working in that language.

The "System Libraries" of an executable work include anything, other than the
work as a whole, that (a) is included in the normal form of packaging a Major
Component, but which is not part of that Major Component, and (b) serves only to
enable use of the work with that Major Component, or to implement a Standard
Interface for which an implementation is available to the public in source code
form. A "Major Component", in this context, means a major essential component
(kernel, window system, and so on) of the specific operating system (if any) on
which the executable work runs, or a compiler used to produce the work, or an
object code interpreter used to run it.

The "Corresponding Source" for a work in object code form means all the source
code needed to generate, install, and (for an executable work) run the object
code and to modify the work, including scripts to control those activities.
However, it does not include the work's System Libraries, or general-purpose
tools or generally available free programs which are used unmodified in
performing those activities but which are not part of the work. For example,
Corresponding Source includes interface definition files associated with source
files for the work, and the source code for shared libraries and dynamically
linked subprograms that the work is specifically designed to require, such as by
intimate data communication or control flow between those subprograms and other
parts of the work.

The Corresponding Source need not include anything that users can regenerate
automatically from other parts of the Corresponding Source.

The Corresponding Source for a work in source code form is that same work.


### 2. Basic Permissions.

All rights granted under this License are granted for the term of copyright on
the Program, and are irrevocable provided the stated conditions are met. This
License explicitly affirms your unlimited permission to run the unmodified
Program. The output from running a covered work is covered by this License only
if the output, given its content, constitutes a covered work. This License
acknowledges your rights of fair use or other equivalent, as provided by
copyright law.

You may make, run and propagate covered works that you do not convey, without
conditions so long as your license otherwise remains in force. You may convey
covered works to others for the sole purpose of having them make modifications
exclusively for you, or provide you with facilities for running those works,
provided that you comply with the terms of this License in conveying all
material for which you do not control copyright. Those thus making or running
the covered works for you must do so exclusively on your behalf, under your
direction and control, on terms that prohibit them from making any copies of
your copyrighted material outside their relationship with you.

Conveying under any other circumstances is permitted solely under the conditions
stated below. Sublicensing is not allowed; section 10 makes it unnecessary.


### 3. Protecting Users' Legal Rights From Anti-Circumvention Law.

No covered work shall be deemed part of an effective technological measure under
any applicable law fulfilling obligations under article 11 of the WIPO copyright
treaty adopted on 20 December 1996, or similar laws prohibiting or restricting
circumvention of such measures.

When you convey a covered work, you waive any legal power to forbid
circumvention of technological measures to the extent such circumvention is
effected by exercising rights under this License with respect to the covered
work, and you disclaim any intention to limit operation or modification of the
work as a means of enforcing, against the work's users, your or third parties'
legal rights to forbid circumvention of technological measures.


### 4. Conveying Verbatim Copies.

You may convey verbatim copies of the Program's source code as you receive it,
in any medium, provided that you conspicuously and appropriately publish on each
copy an appropriate copyright notice; keep intact all notices stating that this
License and any non-permissive terms added in accord with section 7 apply to the
code; keep intact all notices of the absence of any warranty; and give all
recipients a copy of this License along with the Program.

You may charge any price or no price for each copy that you convey, and you may
offer support or warranty protection for a fee.


### 5. Conveying Modified Source Versions.

You may convey a work based on the Program, or the modifications to produce it
from the Program, in the form of source code under the terms of section 4,
provided that you also meet all of these conditions:

*   **a)** The work must carry prominent notices stating that you modified it,
    and giving a relevant date.

*   **b)** The work must carry prominent notices stating that it is released
    under this License and any conditions added under section 7. This
    requirement modifies the requirement in section 4 to "keep intact all
    notices".

*   **c)** You must license the entire work, as a whole, under this License to
    anyone who comes into possession of a copy. This License will therefore
    apply, along with any applicable section 7 additional terms, to the whole of
    the work, and all its parts, regardless of how they are packaged. This
    License gives no permission to license the work in any other way, but it
    does not invalidate such permission if you have separately received it.

*   **d)** If the work has interactive user interfaces, each must display
    Appropriate Legal Notices; however, if the Program has interactive
    interfaces that do not display Appropriate Legal Notices, your work need not
    make them do so.

A compilation of a covered work with other separate and independent works,
which are not by their nature extensions of the covered work, and which are
not combined with it such as to form a larger program, in or on a volume of
a storage or distribution medium, is called an "aggregate" if the
compilation and its resulting copyright are not used to limit the access or
legal rights of the compilation's users beyond what the individual works
permit. Inclusion of a covered work in an aggregate does not cause this
License to apply to the other parts of the aggregate.


### 6. Conveying Non-Source Forms.

You may convey a covered work in object code form under the terms of sections 4
and 5, provided that you also convey the machine-readable Corresponding Source
under the terms of this License, in one of these ways:

*   **a)** Convey the object code in, or embodied in, a physical product
    (including a physical distribution medium), accompanied by the Corresponding
    Source fixed on a durable physical medium customarily used for software
    interchange.

*   **b)** Convey the object code in, or embodied in, a physical product
    (including a physical distribution medium), accompanied by a written offer,
    valid for at least three years and valid for as long as you offer spare
    parts or customer support for that product model, to give anyone who
    possesses the object code either (1) a copy of the Corresponding Source for
    all the software in the product that is covered by this License, on a
    durable physical medium customarily used for software interchange, for a
    price no more than your reasonable cost of physically performing this
    conveying of source, or (2) access to copy the Corresponding Source from a
    network server at no charge.

*   **c)** Convey individual copies of the object code with a copy of the
    written offer to provide the Corresponding Source. This alternative is
    allowed only occasionally and noncommercially, and only if you received the
    object code with such an offer, in accord with subsection 6b.

*   **d)** Convey the object code by offering access from a designated place
    (gratis or for a charge), and offer equivalent access to the Corresponding
    Source in the same way through the same place at no further charge. You need
    not require recipients to copy the Corresponding Source along with the
    object code. If the place to copy the object code is a network server, the
    Corresponding Source may be on a different server (operated by you or a
    third party) that supports equivalent copying facilities, provided you
    maintain clear directions next to the object code saying where to find the
    Corresponding Source. Regardless of what server hosts the Corresponding
    Source, you remain obligated to ensure that it is available for as long as
    needed to satisfy these requirements.

*   **e)** Convey the object code using peer-to-peer transmission, provided you
    inform other peers where the object code and Corresponding Source of the
    work are being offered to the general public at no charge under subsection
    6d.

A separable portion of the object code, whose source code is excluded from
the Corresponding Source as a System Library, need not be included in
conveying the object code work.

A "User Product" is either (1) a "consumer product", which means any
tangible personal property which is normally used for personal, family, or
household purposes, or (2) anything designed or sold for incorporation into
a dwelling. In determining whether a product is a consumer product, doubtful
cases shall be resolved in favor of coverage. For a particular product
received by a particular user, "normally used" refers to a typical or common
use of that class of product, regardless of the status of the particular
user or of the way in which the particular user actually uses, or expects or
is expected to use, the product. A product is a consumer product regardless
of whether the product has substantial commercial, industrial or non-
consumer uses, unless such uses represent the only significant mode of use
of the product.

"Installation Information" for a User Product means any methods, procedures,
authorization keys, or other information required to install and execute
modified versions of a covered work in that User Product from a modified
version of its Corresponding Source. The information must suffice to ensure
that the continued functioning of the modified object code is in no case
prevented or interfered with solely because modification has been made.

If you convey an object code work under this section in, or with, or
specifically for use in, a User Product, and the conveying occurs as part of
a transaction in which the right of possession and use of the User Product
is transferred to the recipient in perpetuity or for a fixed term
(regardless of how the transaction is characterized), the Corresponding
Source conveyed under this section must be accompanied by the Installation
Information. But this requirement does not apply if neither you nor any
third party retains the ability to install modified object code on the User
Product (for example, the work has been installed in ROM).

The requirement to provide Installation Information does not include a
requirement to continue to provide support service, warranty, or updates for
a work that has been modified or installed by the recipient, or for the User
Product in which it has been modified or installed. Access to a network may
be denied when the modification itself materially and adversely affects the
operation of the network or violates the rules and protocols for
communication across the network.

Corresponding Source conveyed, and Installation Information provided, in
accord with this section must be in a format that is publicly documented
(and with an implementation available to the public in source code form),
and must require no special password or key for unpacking, reading or
copying.


### 7. Additional Terms.

"Additional permissions" are terms that supplement the terms of this License by
making exceptions from one or more of its conditions. Additional permissions
that are applicable to the entire Program shall be treated as though they were
included in this License, to the extent that they are valid under applicable
law. If additional permissions apply only to part of the Program, that part may
be used separately under those permissions, but the entire Program remains