Kuva mugadziri maraibhurari (GOST cryptographic primitives in pure Python), ini ndinowanzo gamuchira mibvunzo nezve maitiro ekuita iyo yakapfava yakachengeteka meseji pamabvi. Vanhu vazhinji vanofunga kuti application cryptography iri nyore, uye kufona .encrypt() pablock cipher kunokwana kuti utumire zvakachengeteka pamusoro penzira yekutaurirana. Vamwe vanotenda kuti application cryptography ndiyo magumo evashoma, uye zvinotenderwa kuti makambani akapfuma akaita seTeregiramu ane olympiad-masvomhu. yakachengeteka protocol.
Zvese izvi zvakandikurudzira kunyora chinyorwa ichi kuratidza kuti kuita cryptographic protocol uye kuchengetedza IM harisi basa rakaoma kudaro. Nekudaro, hazvina kukodzera kugadzira yako yechokwadi uye yakakosha chibvumirano mapuroteni.
Nyaya ichanyora , , mutumwa pakarepo ne authentication uye kiyi chibvumirano cheprotocol (pachikonzero chairi kuitwa ), uchishandisa chete GOST cryptographic algorithms PyGOST raibhurari uye ASN.1 meseji encoding raibhurari (zvandatove nazvo ) Chinodiwa: inofanira kunge iri nyore zvekuti inogona kunyorwa kubva pakutanga manheru mamwe (kana zuva rekushanda), kana zvisina kudaro haisisiri chirongwa chiri nyore. Inogona kunge ine zvikanganiso, zvisingakodzeri matambudziko, zvikanganiso, uye ichi ndicho chirongwa changu chekutanga kushandisa asyncio raibhurari.
IM design
Kutanga, isu tinofanirwa kunzwisisa kuti IM yedu ichataridzika sei. Kuti zvive nyore, ngaive network yevaenzani-kune-vezera, pasina kuwanikwa kwevatori vechikamu. Isu pachedu ticharatidza kuti ndeipi kero: chiteshi chekubatanidza kune kutaurirana neanopindirana.
Ini ndinonzwisisa kuti, panguva ino, fungidziro yekuti kutaurirana kwakananga kunowanikwa pakati pemakomputa maviri asina tsananguro chinhu chakakosha pakupikiswa kwekushandiswa kweIM mukuita. Asi vagadziri vanowedzera kushandisa marudzi ese emadondoro eNAT-anotenderera, ticharamba tiri paIPv4 Internet, paine mukana unoodza mwoyo wekutaurirana pakati pemakombuta asina tsarukano. Inguva yakareba sei iwe unogona kushivirira kushomeka kweIPv6 kumba uye kubasa?
Isu tichava neshamwari-kune-shamwari network: ese anogona interlocutors anofanira kuzivikanwa pachine nguva. Chekutanga, izvi zvinorerutsa zvakanyanya zvese: isu takazvisuma isu, takawana kana kusawana zita / kiyi, yakabviswa kana kuenderera mberi nekushanda, tichiziva mutauri. Chechipiri, kazhinji, yakachengeteka uye inobvisa kurwiswa kwakawanda.
Iyo IM interface ichave iri padyo neklass mhinduro , izvo zvandinoda chaizvo kune yavo minimalism uye Unix-nzira uzivi. Iyo IM chirongwa inogadzira dhairekitori ine matatu Unix domain sockets kune yega interlocutor:
- mu-mashoko anotumirwa kune interlocutor akanyorwa mairi;
- kunze - mameseji akagamuchirwa kubva kune interlocutor anoverengwa kubva kwairi;
- nyika - nekuverenga kubva pairi, tinoona kana iyo interlocutor parizvino yakabatana, kero yekubatanidza / chiteshi.
Mukuwedzera, conn socket inogadzirwa, nekunyora chiteshi chengarava umo isu tinotanga kubatana kune kure interlocutor.
|-- alice
| |-- in
| |-- out
| `-- state
|-- bob
| |-- in
| |-- out
| `-- state
`- conn
Iyi nzira inobvumidza iwe kuita yakazvimirira mashandisirwo eIM yekufambisa uye mushandisi interface, nekuti hapana shamwari, haugone kufadza munhu wese. Kushandisa uye / kana , unogona kuwana akawanda-mahwindo interface ine syntax inoratidzira. Uye nerubatsiro unogona kuwana GNU Readline-inoenderana meseji mutsara wekuisa.
Muchokwadi, mapurojekiti anoyamwa anoshandisa mafaira eFIFO. Ini pachangu, ini handina kunzwisisa maitiro ekushanda nemafaira nemakwikwi muasyncio pasina chinyorwa chakanyorwa nemaoko kubva kune tambo dzakatsaurirwa (ndanga ndichishandisa mutauro wezvinhu zvakadaro kwenguva yakareba. ) Naizvozvo, ndakafunga kuita neUnix domain sockets. Nehurombo, izvi zvinoita kuti zvisaite echo 2001:470:dead::babe 6666 > conn. Ndakagadzirisa dambudziko iri ndichishandisa : echo 2001:470:dead::babe 6666 | socat - UNIX-CONNECT:conn, socat READLINE UNIX-CONNECT:alice/in.
Iyo yekutanga isina kuchengeteka protocol
TCP inoshandiswa sekutakura: inovimbisa kutumira uye kurongeka kwayo. UDP haivimbisi (izvo zvingabatsira kana cryptography ikashandiswa), asi rutsigiro Python haibude mubhokisi.
Nehurombo, muTCP hapana pfungwa yemeseji, chete rwizi rwemabheti. Naizvozvo, zvinofanirwa kuuya nefomati yemameseji kuitira kuti vagovane pakati pavo mune ino tambo. Tinogona kubvumirana kushandisa mutsara wekudyisa hunhu. Zvakanaka kune vanotanga, asi kana tangotanga kuvharidzira mameseji edu, uyu hunhu anogona kuoneka chero papi. Mune network, saka, maprotocol akakurumbira ndeaya anotanga kutumira hurefu hwemeseji mumabhayiti. Semuenzaniso, kunze kwebhokisi Python ine xdrlib, iyo inokutendera kuti ushande nefomati yakafanana .
Hatizoshande nemazvo uye nemazvo nekuverenga TCP - isu tichaita kuti kodhi ive nyore. Isu tinoverenga data kubva pane socket mune isingaperi loop kusvika isu tasarudza iyo yakazara meseji. JSON ine XML inogona zvakare kushandiswa sefomati yeiyi nzira. Asi kana cryptography yawedzerwa, iyo data ichafanirwa kusainwa uye kutenderwa - uye izvi zvinoda byte-for-byte yakafanana inomiririra yezvinhu, izvo zvisingapiwe neJSON/XML (kurasa mhedzisiro inogona kusiyana).
XDR inokodzera basa iri, zvisinei ini ndinosarudza ASN.1 neDER encoding uye raibhurari, sezvo tichava nezvinhu zvepamusoro-soro paruoko izvo zvinowanzonyanya kunakidza uye zviri nyore kushanda. Kusiyana schemaless , kana , ASN.1 ichaongorora otomatiki iyo data inopesana neiyo yakaoma-coded schema.
# Msg ::= CHOICE {
# text MsgText,
# handshake [0] EXPLICIT MsgHandshake }
class Msg(Choice):
schema = ((
("text", MsgText()),
("handshake", MsgHandshake(expl=tag_ctxc(0))),
))
# MsgText ::= SEQUENCE {
# text UTF8String (SIZE(1..MaxTextLen))}
class MsgText(Sequence):
schema = ((
("text", UTF8String(bounds=(1, MaxTextLen))),
))
# MsgHandshake ::= SEQUENCE {
# peerName UTF8String (SIZE(1..256)) }
class MsgHandshake(Sequence):
schema = ((
("peerName", UTF8String(bounds=(1, 256))),
))
Meseji yakagamuchirwa ichave Msg: ingave mameseji MsgText (ine ndima imwe chete yemavara parizvino) kana meseji yeMsgHandshake yekubata ruoko (ine zita remutauri). Iye zvino zvinoratidzika zvakanyanya kuoma, asi iyi ndiyo nheyo yeramangwana.
βββββββ βββββββ βPeerAβ βPeerBβ ββββ¬βββ ββkeβ ββkeβs A) β βββββββββ ββββββββ>β β β βMsgHandshake(IdB) β β<βββββββββββββββββ β β MsgText() β βββββ MsgText() β β β
IM pasina cryptography
Sezvandambotaura, iyo asyncio raibhurari ichashandiswa kune ese socket mashandiro. Ngatizivise zvatinotarisira pakuvhurwa:
parser = argparse.ArgumentParser(description="GOSTIM")
parser.add_argument(
"--our-name",
required=True,
help="Our peer name",
)
parser.add_argument(
"--their-names",
required=True,
help="Their peer names, comma-separated",
)
parser.add_argument(
"--bind",
default="::1",
help="Address to listen on",
)
parser.add_argument(
"--port",
type=int,
default=6666,
help="Port to listen on",
)
args = parser.parse_args()
OUR_NAME = UTF8String(args.our_name)
THEIR_NAMES = set(args.their_names.split(","))
Isa zita rako pachako (--yedu-zita alice). Vese vanotarisirwa interlocutors vakanyorwa vakapatsanurwa nemakoma (-mazita avo bob,eve). Kune yega yega interlocutors, dhairekitori ine Unix sockets inogadzirwa, pamwe neiyo coroutine kune yega yega mukati, kunze, nyika:
for peer_name in THEIR_NAMES:
makedirs(peer_name, mode=0o700, exist_ok=True)
out_queue = asyncio.Queue()
OUT_QUEUES[peer_name] = out_queue
asyncio.ensure_future(asyncio.start_unix_server(
partial(unixsock_out_processor, out_queue=out_queue),
path.join(peer_name, "out"),
))
in_queue = asyncio.Queue()
IN_QUEUES[peer_name] = in_queue
asyncio.ensure_future(asyncio.start_unix_server(
partial(unixsock_in_processor, in_queue=in_queue),
path.join(peer_name, "in"),
))
asyncio.ensure_future(asyncio.start_unix_server(
partial(unixsock_state_processor, peer_name=peer_name),
path.join(peer_name, "state"),
))
asyncio.ensure_future(asyncio.start_unix_server(unixsock_conn_processor, "conn"))
Mameseji anobva kumushandisi kubva mu socket anotumirwa ku IN_QUEUES mutsara:
async def unixsock_in_processor(reader, writer, in_queue: asyncio.Queue) -> None:
while True:
text = await reader.read(MaxTextLen)
if text == b"":
break
await in_queue.put(text.decode("utf-8"))
Mameseji anobva kuvanopindirana anotumirwa kuOUT_QUEUES mitsetse, kubva painonyorwa data kune kunze socket:
async def unixsock_out_processor(reader, writer, out_queue: asyncio.Queue) -> None:
while True:
text = await out_queue.get()
writer.write(("[%s] %s" % (datetime.now(), text)).encode("utf-8"))
await writer.drain()
Kana uchiverenga kubva pachisoketi chehurumende, chirongwa chinotarisa kero yeanopindira muduramazwi rePEER_ALIVE. Kana pasina kubatana kune interlocutor zvakadaro, ipapo mutsara usina chinhu unonyorwa.
async def unixsock_state_processor(reader, writer, peer_name: str) -> None:
peer_writer = PEER_ALIVES.get(peer_name)
writer.write(
b"" if peer_writer is None else (" ".join([
str(i) for i in peer_writer.get_extra_info("peername")[:2]
]).encode("utf-8") + b"n")
)
await writer.drain()
writer.close()
Paunenge uchinyora kero kune conn socket, yekubatanidza "initiator" basa rinotangwa:
async def unixsock_conn_processor(reader, writer) -> None:
data = await reader.read(256)
writer.close()
host, port = data.decode("utf-8").split(" ")
await initiator(host=host, port=int(port))
Ngatifungei nezvekutanga. Kutanga zviri pachena inovhura chinongedzo kune yakatsanangurwa host / chiteshi uye inotumira meseji yekubata ruoko ine zita rayo:
130 async def initiator(host, port):
131 _id = repr((host, port))
132 logging.info("%s: dialing", _id)
133 reader, writer = await asyncio.open_connection(host, port)
134 # Handshake message {{{
135 writer.write(Msg(("handshake", MsgHandshake((
136 ("peerName", OUR_NAME),
137 )))).encode())
138 # }}}
139 await writer.drain()
Zvadaro, inomirira mhinduro kubva kubati iri kure. Inoedza kutsanangura mhinduro inouya uchishandisa Msg ASN.1 chirongwa. Isu tinofungidzira kuti meseji yese ichatumirwa muchikamu chimwe cheTCP uye isu tichaigamuchira paatomu kana tichifona .read(). Takatarisa kuti tatambira here meseji yekubata maoko.
141 # Wait for Handshake message {{{
142 data = await reader.read(256)
143 if data == b"":
144 logging.warning("%s: no answer, disconnecting", _id)
145 writer.close()
146 return
147 try:
148 msg, _ = Msg().decode(data)
149 except ASN1Error:
150 logging.warning("%s: undecodable answer, disconnecting", _id)
151 writer.close()
152 return
153 logging.info("%s: got %s message", _id, msg.choice)
154 if msg.choice != "handshake":
155 logging.warning("%s: unexpected message, disconnecting", _id)
156 writer.close()
157 return
158 # }}}
Tinotarisa kuti zita rakagamuchirwa re interlocutor rinozivikanwa kwatiri. Kana zvisina kudaro, saka tinoputsa kubatana. Isu tinotarisa kana isu takatogadzira hukama naye (mupindiri zvakare akapa murairo wekubatanidza kwatiri) uye kuvhara. The IN_QUEUES queue inobata Python tambo dzine chinyorwa chemeseji, asi ine yakakosha kukosha kweNone inosaina msg_sender coroutine kumira kushanda kuitira kuti ikanganwe nezve munyori wayo ane chekuita nenhaka TCP yekubatanidza.
159 msg_handshake = msg.value
160 peer_name = str(msg_handshake["peerName"])
161 if peer_name not in THEIR_NAMES:
162 logging.warning("unknown peer name: %s", peer_name)
163 writer.close()
164 return
165 logging.info("%s: session established: %s", _id, peer_name)
166 # Run text message sender, initialize transport decoder {{{
167 peer_alive = PEER_ALIVES.pop(peer_name, None)
168 if peer_alive is not None:
169 peer_alive.close()
170 await IN_QUEUES[peer_name].put(None)
171 PEER_ALIVES[peer_name] = writer
172 asyncio.ensure_future(msg_sender(peer_name, writer))
173 # }}}
msg_sender inogamuchira mameseji anobuda (akaiswa mumutsara kubva mune socket), anoaisa mu meseji yeMsgText uye anoatumira kuburikidza neTCP yekubatanidza. Inogona kutyora chero nguva - isu tinonyatso gamuchira izvi.
async def msg_sender(peer_name: str, writer) -> None:
in_queue = IN_QUEUES[peer_name]
while True:
text = await in_queue.get()
if text is None:
break
writer.write(Msg(("text", MsgText((
("text", UTF8String(text)),
)))).encode())
try:
await writer.drain()
except ConnectionResetError:
del PEER_ALIVES[peer_name]
return
logging.info("%s: sent %d characters message", peer_name, len(text))
Pakupedzisira, mutangi anopinda musingaverengeki loop yekuverenga mameseji kubva pane socket. Inotarisa kana mameseji aya ari mameseji uye oaisa mu OUT_QUEUES mutsara, kubva paachazotumirwa kune kunze socket yeanopindirana. Sei usingakwanisi kungoita .read() uye decode meseji? Nekuti zvinogoneka kuti mameseji akati wandei kubva kumushandisi achaunganidzwa musystem yekushandisa buffer uye kutumirwa mune imwe TCP chikamu. Isu tinokwanisa decode yekutanga, uyezve chikamu cheinotevera chinogona kuramba chiri mubuffer. Mune chero mamiriro ezvinhu asina kujairika, tinovhara kubatana kweTCP uye kumisa msg_sender coroutine (nekutumira Hapana kune OUT_QUEUES mutsara).
174 buf = b""
175 # Wait for test messages {{{
176 while True:
177 data = await reader.read(MaxMsgLen)
178 if data == b"":
179 break
180 buf += data
181 if len(buf) > MaxMsgLen:
182 logging.warning("%s: max buffer size exceeded", _id)
183 break
184 try:
185 msg, tail = Msg().decode(buf)
186 except ASN1Error:
187 continue
188 buf = tail
189 if msg.choice != "text":
190 logging.warning("%s: unexpected %s message", _id, msg.choice)
191 break
192 try:
193 await msg_receiver(msg.value, peer_name)
194 except ValueError as err:
195 logging.warning("%s: %s", err)
196 break
197 # }}}
198 logging.info("%s: disconnecting: %s", _id, peer_name)
199 IN_QUEUES[peer_name].put(None)
200 writer.close()
66 async def msg_receiver(msg_text: MsgText, peer_name: str) -> None:
67 text = str(msg_text["text"])
68 logging.info("%s: received %d characters message", peer_name, len(text))
69 await OUT_QUEUES[peer_name].put(text)
Ngatidzokei kune kodhi huru. Mushure mekugadzira ese coroutines panguva iyo chirongwa chinotanga, tinotanga iyo TCP server. Kune yega yega yakagadzwa yekubatanidza, inogadzira anopindura coroutine.
logging.basicConfig(
level=logging.INFO,
format="%(levelname)s %(asctime)s: %(funcName)s: %(message)s",
)
loop = asyncio.get_event_loop()
server = loop.run_until_complete(asyncio.start_server(responder, args.bind, args.port))
logging.info("Listening on: %s", server.sockets[0].getsockname())
loop.run_forever()
anopindura akafanana neanotanga uye magirazi zviito zvese zvakafanana, asi iyo isingaperi loop yekuverenga mameseji inotanga pakarepo, kuitira nyore. Parizvino, iyo handshake protocol inotumira meseji kubva kune rumwe rutivi, asi mune ramangwana pachava maviri kubva kune yekubatanidza yekutanga, mushure meiyo mameseji anogona kutumirwa nekukurumidza.
72 async def responder(reader, writer):
73 _id = writer.get_extra_info("peername")
74 logging.info("%s: connected", _id)
75 buf = b""
76 msg_expected = "handshake"
77 peer_name = None
78 while True:
79 # Read until we get Msg message {{{
80 data = await reader.read(MaxMsgLen)
81 if data == b"":
82 logging.info("%s: closed connection", _id)
83 break
84 buf += data
85 if len(buf) > MaxMsgLen:
86 logging.warning("%s: max buffer size exceeded", _id)
87 break
88 try:
89 msg, tail = Msg().decode(buf)
90 except ASN1Error:
91 continue
92 buf = tail
93 # }}}
94 if msg.choice != msg_expected:
95 logging.warning("%s: unexpected %s message", _id, msg.choice)
96 break
97 if msg_expected == "text":
98 try:
99 await msg_receiver(msg.value, peer_name)
100 except ValueError as err:
101 logging.warning("%s: %s", err)
102 break
103 # Process Handshake message {{{
104 elif msg_expected == "handshake":
105 logging.info("%s: got %s message", _id, msg_expected)
106 msg_handshake = msg.value
107 peer_name = str(msg_handshake["peerName"])
108 if peer_name not in THEIR_NAMES:
109 logging.warning("unknown peer name: %s", peer_name)
110 break
111 writer.write(Msg(("handshake", MsgHandshake((
112 ("peerName", OUR_NAME),
113 )))).encode())
114 await writer.drain()
115 logging.info("%s: session established: %s", _id, peer_name)
116 peer_alive = PEER_ALIVES.pop(peer_name, None)
117 if peer_alive is not None:
118 peer_alive.close()
119 await IN_QUEUES[peer_name].put(None)
120 PEER_ALIVES[peer_name] = writer
121 asyncio.ensure_future(msg_sender(peer_name, writer))
122 msg_expected = "text"
123 # }}}
124 logging.info("%s: disconnecting", _id)
125 if msg_expected == "text":
126 IN_QUEUES[peer_name].put(None)
127 writer.close()
Secure protocol
Yasvika nguva yekuchengetedza kutaurirana kwedu. Tinorevei nekuchengeteka uye chii chatinoda:
- kuvanzika kwemameseji anofambiswa;
- chokwadi uye kuvimbika kwemameseji anofambiswa - shanduko dzavo dzinofanira kuonekwa;
- dziviriro kubva pakurwiswa kwekudzokorora - chokwadi chekushaikwa kana kudzokororwa meseji inofanira kuonekwa (uye isu tinosarudza kumisa kubatana);
- kuzivikanwa uye kutendeseka kwevanopindirana vachishandisa pre-yakapinda veruzhinji makiyi - isu takatosarudza kare kuti taigadzira shamwari-ku-shamwari network. Chete mushure mehuchokwadi ndipo patinozonzwisisa watiri kutaurirana naye;
- kuwanikwa zvivakwa (PFS) - kukanganisa kiyi yedu yekusaina yekugara kwenguva refu haifanire kutungamira mukukwanisa kuverenga zvese zvakapfuura tsamba. Kurekodha yakabatwa traffic inova isina basa;
- chokwadi / kutendeseka kwemameseji (kutakura uye kubata maoko) chete mukati mechikamu chimwe cheTCP. Kupinza meseji dzakasainwa nemazvo kubva kune imwe chikamu (kunyangwe nemutauriri mumwe chete) hazvifanirwe kuitika;
- munhu anongotarisa haafanire kuona chero zviziviso zvevashandisi, zvinotapurirwa makiyi eruzhinji anogara kwenguva refu, kana hashi kubva mazviri. Kumwe kusazivikanwa kubva kune anoona zvake.
Sezvineiwo, anenge munhu wese anoda kuve neichi chishoma mune chero ruoko protocol, uye zvishoma zviri pamusoro zvinozosangana zve "pamba" mapuroteni. Iye zvino hatisi kuzogadzira chero chinhu chitsva. Ndinonyatso kurudzira kushandisa yekuvaka maprotocol, asi ngatisarudze chimwe chinhu chakareruka.
Iwo maviri anonyanya kufarirwa maprotocol ndeaya:
- - protocol yakaoma kwazvo ine nhoroondo refu yezvipembenene, jambs, kushaya simba, kufunga kwakashata, kuomarara uye kukanganisa (zvisinei, izvi zvine zvishoma zvekuita neTLS 1.3). Asi isu hatizvifungire nekuti yakanyanya kuoma.
- Ρ - usave nematambudziko akakomba e-cryptographic, kunyangwe asiriwo ari nyore. Kana iwe ukaverenga nezve IKEv1 uye IKEv2, saka sosi yavo ndeye , ISO/IEC IS 9798-3 uye SIGMA (SIGn-uye-MAc) mapuroteni - ari nyore kuita manheru mamwe chete.
Chii chakanaka nezveSIGMA, seyazvino chinongedzo mukuvandudzwa kweSTS/ISO protocol? Iyo inosangana nezvose zvatinoda (kusanganisira "kuvanza" interlocutor identifiers) uye haina inozivikanwa cryptographic matambudziko. Iyo minimalistic - kubvisa chimwe chinhu kubva kune protocol meseji kunotungamira mukusachengeteka kwayo.
Ngatibvei kubva kune yakapusa-yakakura-protocol toenda kuSIGMA. Kuvhiya kwakanyanya kwatinofarira ndekwe : Basa rinoburitsa vese vatori vechikamu kukosha kwakafanana, iyo inogona kushandiswa sekiyi inoenzanirana. Pasina kupinda mune zvakadzama: bato rega rega rinogadzira ephemeral (inoshandiswa chete mukati mechikamu chimwe chete) kiyi mbiri (yeruzhinji uye yakavanzika makiyi), inotsinhanisa makiyi eruzhinji, inodaidza basa rechibvumirano, kune iyo yekupinza yavanopfuudza yavo yakavanzika kiyi uye yeruzhinji kiyi ye. mutauriri.
βββββββ βββββββ βPeerAβ βPeerBβ ββββ¬βββ βββ Ipua, β βββββββββββ βββββββββββ ββββββββββββββββ>β βPrvA β β βPrvA,Pub. β ββββββββ ββββββββββββ β IdB, PubB β<ββββββββ βββββββ βPrvB, PubB = DHgen()β β β ββββββββββββββββββββββββββββββ ββββ βββββ ββββ§βββββββββββββ β βKey = DH(PrvA, PubB)β <βββββββββββββββββ βββββββ βββββ β β β β
Chero ani zvake anogona kusvetukira pakati uye kutsiva makiyi eruzhinji neavo - hapana humbowo hwevanopindirana mune iyi protocol. Ngatiwedzere siginicha ine makiyi enguva refu.
βββββββ βββββββ βPeerAβ βPeerBβ ββββ¬βββ βββ βββ βββ SignPrvA, (PubA)) β ββ ββββββββββββ ββββββββββ ββββββββββββSaina bA = mutoro()β β β βPrvA, PubA = DHgen() β β β ββββββββ βββββββ βββββββββββββββββββββ , sign(SignPrvB, (PubB)) β βββββββββββββββ βββββββ βββββββββ βββββββ ββββββββββ βββββββββββββ βββ βSignPrvB, SignPubB = mutoro( )β β β βPrvB, Pub β β β β β βββββββββ ββββββββββββββ βββ βββββ β ββββββ β β βverify( SignPub. ββ β β β
Siginecha yakadaro haishande, nekuti haina kusungirirwa kune imwe nguva. Mameseji akadai "akakodzera" kumisangano nevamwe vatori vechikamu. Chimiro chese chinofanira kunyoresa. Izvi zvinotimanikidza kuwedzera imwe meseji kubva kuA.
Pamusoro pezvo, zvakakosha kuti uwedzere chiziviso chako pasi pe siginicha, sezvo tikasadaro tinogona kutsiva IdXXX uye kusainazve meseji nekiyi yemumwe anozivikanwa interlocutor. Kudzivirira , zvinodikanwa kuti zvinhu zviri pasi pesiginicha zvive munzvimbo dzakanyatsotsanangurwa zvinoenderana nezvazvinoreva: kana A zviratidzo (PubA, PubB), ipapo B anofanira kusaina (PubB, PubA). Izvi zvinotaurawo nezvekukosha kwekusarudza chimiro uye fomati yeserialized data. Semuenzaniso, seti muASN.1 DER encoding yakarongedzwa: SET OF(PubA, PubB) ichafanana neSET OF(PubB, PubA).
βββββββ βββββββ βPeerAβ βPeerBβ ββββ¬βββ βββ Ipua, β βββββββββββ ββββββββββββββββ ββββββββββββββββ βββββββββ ββββββββββββ>β βSignPrvA, SignPubA = mutoro()β β β βPrvA, PubA = DHgen() β β β β βββββββ ββββββββββββββββ βIdB, PubB, sign(SignPrvB, (IdB, PubA, PubB)) βββββ ββββββββββββ β<ββββββββββββββββββ βββββββββ ββββββββββ βSignPrvB, SignPubB = mutoro()β β β βPrvB, PubB = DHgen() β β β β ββββββββ ββββββββ βββββββββββ β sign(SignPrvA, (IdA, PubB, PubA)) β βββββββββββββββββββββββ βββββ ββ ββββββββββββββββββββββββββββββββββββ βββ>β βverify(SignPubB, ...) β β β βkiyi = dh (prva, PUBB) β β β β
Nekudaro, isu hatisati "takaratidza" kuti takagadzira imwechete yakagovaniswa kiyi yechikamu chino. Muchidimbu, tinogona kuita pasina danho iri - iyo yekutanga yekufambisa yekubatanidza ichave isingashande, asi isu tinoda kuti kana kubatwa kwemaoko kwapera, isu tinoita chokwadi chekuti zvese zvinonyatso kubvumirana. Parizvino isu tine ISO/IEC IS 9798-3 protocol paruoko.
Tinogona kusaina kiyi yakagadzirwa pachayo. Izvi zvine njodzi, sezvo zvichikwanisika kuti panogona kuve nekuvuza mune siginecha algorithm inoshandiswa (kunyangwe bits-per-siginicha, asi ichiri kuvuza). Zvinogoneka kusaina hashi yekiyi yekubvisa, asi kudonhedza kunyange hashi yekiyi yakatorwa kunogona kuve kwakakosha mukurwisa kwechisimba-simba pane basa rekubvisa. SIGMA inoshandisa MAC basa rinosimbisa iyo yekutumira ID.
βββββββ βββββββ βPeerAβ βPeerBβ ββββ¬βββ βββ Ipua, β βββββββββββ ββββββββββββββββ ββββββββββββββββ βββββββββ ββββββββββββ- β βββββββ βββββββββββββββββββββ βIdB, PubB, sign(SignPrvB, (PubA, PubIB)β), MAC βββ βββ β<βββββββββββββββββ ββββββββββ ββββββ βββββββββ ββ βSignPrvB, SignPubB = load()β β β βPrvB, PubB = DHgen() β β β βββββ ββββββββββββββββββββββ βββββββββ βββ β β βββββββββββββ ββββββββββ ββββ β sign),(Pubb)(Pub) β βKiyi = DH( PrvA, PubB) β ββββββββββββββββββββββ ββ ββββββββββ βββββββββ βββββ>β βverify(Key, IdB) β β β βverify(SignPubB, ...)β β β βββββββββββββββββββββ βββββ ββ β β
Sekugonesa, vamwe vangangoda kushandisazve makiyi avo ephemeral (zvinova, zvechokwadi, zvinosiririsa kuPFS). Semuenzaniso, takagadzira peya kiyi, takaedza kubatanidza, asi TCP yakanga isipo kana kuti yakakanganiswa pane imwe nzvimbo pakati peprotocol. Zvinonyadzisa kuparadza entropy uye processor zviwanikwa pane imwe nyowani. Naizvozvo, isu tichasuma iyo inonzi cookie - pseudo-random kukosha iyo inodzivirira kubva pane zvingangoita zvemango replay kurwiswa kana uchishandisa zvakare ephemeral makiyi eruzhinji. Nekuda kwekusungirirwa pakati pekuki nekiyi yeruzhinji ephemeral, kiyi yeruzhinji yerimwe bato inogona kubviswa kubva mukusaina sekusina basa.
βββββββ βββββββ βPeerAβ βPeerBβ ββββ¬βββ βββββββId A β βββββββββ ββββββββββββββββββ βββββββββββββ βββββββββ ββββββββββββββββββββββββββββββββββββ β> β βββSignPrvA, SignPubA = mutoro( )β β β βPrvA, PubA = DHgen() β β β ββββββββββββββββββββββββββββββββββββββββββββββββββββ βββ βIdB, PubB, CookieB , saina(SignPrvB, (CookieA, CookieB, PubB)), MAC(IdB) β ββββββββββββββββββββββββββββββββββββββββββ β β β< ββββββββββββββββββββββββββββββββββββ βββββββββ ββββββββββββββββββββ βSignPrvB, SignPubB = load()β β β βB) β βββββββ ββββββββββββββββββββββ β β ββββββββββββββ ββββββββ β sign( SignPrvA, (CookieB, CookieA, PubA)), MAC(IdA) β βKiyi = DH(PrvA, PubB) β βββββββββββββββ β ββ βββββββββββββββββββββββββββββββββββ βββββββ>β β simbisa(Kiyi, IdB) β β β β simbisa(SignPubB, ...)β β β ββββββββββββββββββββββββββββββββββββββββββββββββββββββββββ β β
Chekupedzisira, tinoda kuwana kuvanzika kwevatinobata navo hurukuro kubva kune anoona zvake. Kuti uite izvi, SIGMA inokurudzira kutanga kuchinjana ephemeral makiyi uye kugadzira kiyi yakajairwa iyo yekuvharira echokwadi uye yekuzivisa mameseji. SIGMA inotsanangura sarudzo mbiri:
- SIGMA-I - inodzivirira muvambi kubva pakurwiswa kwakasimba, anopindura kubva kune anozvimiririra: muvambi anosimbisa anopindura uye kana chimwe chinhu chisingaenderane, saka hachipi chitupa chayo. Mupomerwi anopa chiziviso chake kana protocol inoshanda yatangwa naye. Mucherechedzi asina chaanodzidzira;
SIGMA-R - inodzivirira anopindura kubva pakurwiswa kunoshanda, mutangi kubva kune anongoita. Zvese zvakapesana, asi muprotocol mana mameseji ekubata maoko atofambiswa.Isu tinosarudza SIGMA-Ini sezvo yakanyanya kufanana nezvatinotarisira kubva kune mutengi-server zvinhu zvinozivikanwa: mutengi anozivikanwa chete neiyo yakavimbiswa sevha, uye munhu wese anotoziva sevha. Uyezve zviri nyore kuita nekuda kwemameseji mashoma ekubata maoko. Zvese zvatinowedzera kuprotocol ndeye encrypt chikamu chemeseji uye kuendesa identifier A kune yakavharidzirwa chikamu chekupedzisira meseji:
PubA, cookiesA βββββββββ βββββ ββββββββββ ββββββββββββββββββ ββββββββββ βββββ ββββββ>β βSignPrvA , SignPubA = load()β β β βPrvA, PubA = DHgen() βββ β ββββββββ βββββββββ βββββ β PubB, CookieB, Enc((IdB, sign(SignPrvB, (CookieA, CookieB, PubB)), MAC(Idβββ) ββββββββββββββ ββββββββ β<ββββββββββ βββββββββ βββββ ββββββββββ βSignP rvB, SignPubB = load()β β β β PrvB, PubB = DHgen β β β ββββββββ βββββββββββββββββ β β ββββββββββββββββββββββββ βββ β Enc((IdA, sign( SignPrvA, (CookieB, CookieA, PubA)), MAC(IdA))) β βKiyi = DH(PrvA, PubB) β ββββββββββββββ β βββββββββββββββββ ββββββββββ βββββββββ ββββββββββ ββββββ>β βverify(Kiyi, IdB) β β β βverify( SignPubB, ...)β β β βββββββββββββββββββββ βββββ βββ β β
- GOST R inoshandiswa pakusaina algorithm ine 256-bit kiyi.
- Kugadzira kiyi yeruzhinji, 34.10-2012 VKO inoshandiswa.
- CMAC inoshandiswa seMAC. Nehunyanzvi, iyi ndiyo nzira yakakosha yekushanda kwe block cipher, inotsanangurwa muGOST R 34.13-2015. Sebasa rekunyorera reiyi modhi - (34.12-2015).
- Iyo hashi yekiyi yake yeruzhinji inoshandiswa semutauri weinterlocutor. Inoshandiswa sehashi (34.11/2012/256 XNUMX bits).
Mushure mekubata maoko, tichabvumirana pane kiyi yakagovaniswa. Tinogona kuishandisa kune yakatendeseka encryption yemameseji ekufambisa. Ichi chikamu chiri nyore uye chakaoma kuita chikanganiso: isu tinowedzera iyo meseji counter, encrypt meseji, simbisa (MAC) iyo counter uye ciphertext, tumira. Kana tichitambira meseji, tinoongorora kuti counter ine hukoshi hunotarisirwa, simbisa ciphertext nekaunda, toibvisa. Ndeipi kiyi yandinofanira kushandisa kunyora mameseji ekubata maoko, mameseji ekufambisa, uye maitiro ekuasimbisa? Kushandisa kiyi imwe pamabasa ese aya kune ngozi uye kusachenjera. Izvo zvinodikanwa kugadzira makiyi uchishandisa yakasarudzika mabasa (key derivation function). Zvakare, ngatirege kuparadzanisa bvudzi uye kugadzira chimwe chinhu: yave ichizivikanwa kwenguva refu, yakatsvakurudzwa zvakanaka uye haina matambudziko anozivikanwa. Nehurombo, raibhurari yePython yekuzvarwa haina basa iri, saka tinoshandisa plastic bag. HKDF mukati inoshandisa , iyo inoshandisawo hashi basa. Muenzaniso kushandiswa muPython pane peji reWikipedia inotora mitsetse mishoma yekodhi. Sezvakaitika muna 34.10/2012/256, tichashandisa Stribog-XNUMX sebasa rehashi. Kubuda kwebasa redu rechibvumirano chakakosha kuchadaidzwa kuti kiyi yesesheni, kubva kwairi kusiko symmetric inogadzirwa:
kdf = Hkdf(None, key_session, hash=GOST34112012256) kdf.expand(b"handshake1-mac-identity") kdf.expand(b"handshake1-enc") kdf.expand(b"handshake1-mac") kdf.expand(b"handshake2-mac-identity") kdf.expand(b"handshake2-enc") kdf.expand(b"handshake2-mac") kdf.expand(b"transport-initiator-enc") kdf.expand(b"transport-initiator-mac") kdf.expand(b"transport-responder-enc") kdf.expand(b"transport-responder-mac")Zvirongwa/Zvirongwa
Ngatitarisei kuti ndezvipi ASN.1 zvimiro zvatave nazvo zvekufambisa data rese:
class Msg(Choice): schema = (( ("text", MsgText()), ("handshake0", MsgHandshake0(expl=tag_ctxc(0))), ("handshake1", MsgHandshake1(expl=tag_ctxc(1))), ("handshake2", MsgHandshake2(expl=tag_ctxc(2))), )) class MsgText(Sequence): schema = (( ("payload", MsgTextPayload()), ("payloadMac", MAC()), )) class MsgTextPayload(Sequence): schema = (( ("nonce", Integer(bounds=(0, float("+inf")))), ("ciphertext", OctetString(bounds=(1, MaxTextLen))), )) class MsgHandshake0(Sequence): schema = (( ("cookieInitiator", Cookie()), ("pubKeyInitiator", PubKey()), )) class MsgHandshake1(Sequence): schema = (( ("cookieResponder", Cookie()), ("pubKeyResponder", PubKey()), ("ukm", OctetString(bounds=(8, 8))), ("ciphertext", OctetString()), ("ciphertextMac", MAC()), )) class MsgHandshake2(Sequence): schema = (( ("ciphertext", OctetString()), ("ciphertextMac", MAC()), )) class HandshakeTBE(Sequence): schema = (( ("identity", OctetString(bounds=(32, 32))), ("signature", OctetString(bounds=(64, 64))), ("identityMac", MAC()), )) class HandshakeTBS(Sequence): schema = (( ("cookieTheir", Cookie()), ("cookieOur", Cookie()), ("pubKeyOur", PubKey()), )) class Cookie(OctetString): bounds = (16, 16) class PubKey(OctetString): bounds = (64, 64) class MAC(OctetString): bounds = (16, 16)HandshakeTBS ndiyo ichasainwa. HandshakeTBE - chii chichave chakanyorwa. Ini ndinokwevera kutarisa kwako kumunda weukm muMsgHandshake1. 34.10 VKO, kune yakatokura randomisation yemakiyi akagadzirwa, inosanganisira iyo UKM (mushandisi keying material) parameter - kungowedzera entropy.
Kuwedzera Cryptography kune Code
Ngatitarisei chete shanduko dzakaitwa kune yekutanga kodhi, sezvo dhizaini yakaramba yakafanana (chaizvoizvo, kuitisa kwekupedzisira kwakanyorwa kutanga, uyezve cryptography yese yakatemwa kubva mairi).
Sezvo kuvimbiswa uye kuzivikanwa kwevanopindirana kuchaitwa uchishandisa makiyi eruzhinji, ivo zvino vanofanirwa kuchengetwa kumwe kwenguva yakareba. Kuti zvive nyore, tinoshandisa JSON seizvi:
{ "our": { "prv": "21254cf66c15e0226ef2669ceee46c87b575f37f9000272f408d0c9283355f98", "pub": "938c87da5c55b27b7f332d91b202dbef2540979d6ceaa4c35f1b5bfca6df47df0bdae0d3d82beac83cec3e353939489d9981b7eb7a3c58b71df2212d556312a1" }, "their": { "alice": "d361a59c25d2ca5a05d21f31168609deeec100570ac98f540416778c93b2c7402fd92640731a707ec67b5410a0feae5b78aeec93c4a455a17570a84f2bc21fce", "bob": "aade1207dd85ecd283272e7b69c078d5fae75b6e141f7649ad21962042d643512c28a2dbdc12c7ba40eb704af920919511180c18f4d17e07d7f5acd49787224a" } }yedu - yedu kiyi mbiri, hexadecimal yakavanzika uye yeruzhinji makiyi. avo - mazita evanopindirana uye makiyi avo eruzhinji. Ngatichinjei mutsara wemirairo nharo uye tiwedzere post-kugadzirisa yeJSON data:
from pygost import gost3410 from pygost.gost34112012256 import GOST34112012256 CURVE = gost3410.GOST3410Curve( *gost3410.CURVE_PARAMS["GostR3410_2001_CryptoPro_A_ParamSet"] ) parser = argparse.ArgumentParser(description="GOSTIM") parser.add_argument( "--keys-gen", action="store_true", help="Generate JSON with our new keypair", ) parser.add_argument( "--keys", default="keys.json", required=False, help="JSON with our and their keys", ) parser.add_argument( "--bind", default="::1", help="Address to listen on", ) parser.add_argument( "--port", type=int, default=6666, help="Port to listen on", ) args = parser.parse_args() if args.keys_gen: prv_raw = urandom(32) pub = gost3410.public_key(CURVE, gost3410.prv_unmarshal(prv_raw)) pub_raw = gost3410.pub_marshal(pub) print(json.dumps({ "our": {"prv": hexenc(prv_raw), "pub": hexenc(pub_raw)}, "their": {}, })) exit(0) # Parse and unmarshal our and their keys {{{ with open(args.keys, "rb") as fd: _keys = json.loads(fd.read().decode("utf-8")) KEY_OUR_SIGN_PRV = gost3410.prv_unmarshal(hexdec(_keys["our"]["prv"])) _pub = hexdec(_keys["our"]["pub"]) KEY_OUR_SIGN_PUB = gost3410.pub_unmarshal(_pub) KEY_OUR_SIGN_PUB_HASH = OctetString(GOST34112012256(_pub).digest()) for peer_name, pub_raw in _keys["their"].items(): _pub = hexdec(pub_raw) KEYS[GOST34112012256(_pub).digest()] = { "name": peer_name, "pub": gost3410.pub_unmarshal(_pub), } # }}}Iyo yakavanzika kiyi ye34.10 algorithm inhamba isina kurongeka. 256-bit size ye 256-bit elliptic curves. PyGOST haishande neseti yemabheti, asi ne , saka kiyi yedu yakavanzika (urandom(32)) inoda kushandurwa kuita nhamba uchishandisa gost3410.prv_unmarshal(). Kiyi yeruzhinji inotemerwa zvine mutsindo kubva kukiyi yakavanzika uchishandisa gost3410.public_key(). Kiyi yeruzhinji 34.10 inhamba huru mbiri dzinodawo kushandurwa kuita byte sequence kuitira kurerutsira kuchengetedza uye kutapurirana uchishandisa gost3410.pub_marshal().
Mushure mekuverenga faira reJSON, makiyi eruzhinji anofanirwa kudzoserwa kumashure uchishandisa gost3410.pub_unmarshal(). Sezvo isu tichizogamuchira zviziviso zvevanopindirana muchimiro chehashi kubva kukiyi yeruzhinji, vanogona kuverengerwa nekukurumidza uye kuiswa muduramazwi nekukurumidza kutsvaga. Stribog-256 hash is gost34112012256.GOST34112012256(), iyo inogutsa zvizere iyo hashib interface yehashi mabasa.
Ko coroutine yekutanga yakachinja sei? Zvese zvinoenderana nechirongwa chekubata maoko: isu tinogadzira cookie (128-bit yakawanda), ephemeral kiyi pair 34.10, iyo ichashandiswa kune iyo VKO yakakosha chibvumirano basa.
395 async def initiator(host, port): 396 _id = repr((host, port)) 397 logging.info("%s: dialing", _id) 398 reader, writer = await asyncio.open_connection(host, port) 399 # Generate our ephemeral public key and cookie, send Handshake 0 message {{{ 400 cookie_our = Cookie(urandom(16)) 401 prv = gost3410.prv_unmarshal(urandom(32)) 402 pub_our = gost3410.public_key(CURVE, prv) 403 pub_our_raw = PubKey(gost3410.pub_marshal(pub_our)) 404 writer.write(Msg(("handshake0", MsgHandshake0(( 405 ("cookieInitiator", cookie_our), 406 ("pubKeyInitiator", pub_our_raw), 407 )))).encode()) 408 # }}} 409 await writer.drain()- isu tinomirira mhinduro uye tinosarudza iyo inouya Msg meseji;
- ita shuwa kuti wabata ruoko1;
- decode ephemeral public kiyi yerimwe bato uye verenga kiyi yesesheni;
- Isu tinogadzira symmetric kiyi inodiwa kugadzirisa iyo TBE chikamu chemeseji.
423 logging.info("%s: got %s message", _id, msg.choice) 424 if msg.choice != "handshake1": 425 logging.warning("%s: unexpected message, disconnecting", _id) 426 writer.close() 427 return 428 # }}} 429 msg_handshake1 = msg.value 430 # Validate Handshake message {{{ 431 cookie_their = msg_handshake1["cookieResponder"] 432 pub_their_raw = msg_handshake1["pubKeyResponder"] 433 pub_their = gost3410.pub_unmarshal(bytes(pub_their_raw)) 434 ukm_raw = bytes(msg_handshake1["ukm"]) 435 ukm = ukm_unmarshal(ukm_raw) 436 key_session = kek_34102012256(CURVE, prv, pub_their, ukm, mode=2001) 437 kdf = Hkdf(None, key_session, hash=GOST34112012256) 438 key_handshake1_mac_identity = kdf.expand(b"handshake1-mac-identity") 439 key_handshake1_enc = kdf.expand(b"handshake1-enc") 440 key_handshake1_mac = kdf.expand(b"handshake1-mac")UKM inhamba ye64-bit (urandom(8)), inodawo deserialization kubva pakumiririra kwayo byte uchishandisa gost3410_vko.ukm_unmarshal(). VKO basa re34.10/2012/256 3410-bit is gost34102012256_vko.kek_XNUMX() (KEK - encryption key).
Iyo yakagadzirwa chikamu kiyi yatove 256-bit pseudo-random byte sequence. Naizvozvo, inogona kushandiswa nekukurumidza muHKDF mabasa. Sezvo GOST34112012256 ichigutsa hahlib interface, inogona kushandiswa nekukurumidza mukirasi yeHkdf. Isu hatitsanangure munyu (nharo yekutanga yeHkdf), sezvo kiyi yakagadzirwa, nekuda kweiyo ephemerality yevatori vechikamu makiyi maviri, ichave yakasiyana pachikamu chega chega uye yatove neyakakwana entropy. kdf.expand() by default inotogadzira 256-bit kiyi inodiwa kuGrasshopper gare gare.
Tevere, zvikamu zveTBE neTBS zvemeseji iri kuuya zvinotariswa:
- iyo MAC pamusoro peiyo inouya ciphertext inoverengerwa nekutariswa;
- the ciphertext is decrypted;
- TBE chimiro chakatemwa;
- iyo identifier ye interlocutor inotorwa kubva mairi uye inotariswa kana iye anozivikanwa kwatiri zvachose;
- MAC pamusoro peichi chiziviso inoverengerwa nekutariswa;
- siginicha pamusoro peiyo TBS chimiro inosimbiswa, iyo inosanganisira cookie yemapato ese uye yeruzhinji ephemeral kiyi yerimwe bato. Siginicha inosimbiswa nekiyi yekugara kwenguva refu siginecha ye interlocutor.
441 try: 442 peer_name = validate_tbe( 443 msg_handshake1, 444 key_handshake1_mac_identity, 445 key_handshake1_enc, 446 key_handshake1_mac, 447 cookie_our, 448 cookie_their, 449 pub_their_raw, 450 ) 451 except ValueError as err: 452 logging.warning("%s: %s, disconnecting", _id, err) 453 writer.close() 454 return 455 # }}} 128 def validate_tbe( 129 msg_handshake: Union[MsgHandshake1, MsgHandshake2], 130 key_mac_identity: bytes, 131 key_enc: bytes, 132 key_mac: bytes, 133 cookie_their: Cookie, 134 cookie_our: Cookie, 135 pub_key_our: PubKey, 136 ) -> str: 137 ciphertext = bytes(msg_handshake["ciphertext"]) 138 mac_tag = mac(GOST3412Kuznechik(key_mac).encrypt, KUZNECHIK_BLOCKSIZE, ciphertext) 139 if not compare_digest(mac_tag, bytes(msg_handshake["ciphertextMac"])): 140 raise ValueError("invalid MAC") 141 plaintext = ctr( 142 GOST3412Kuznechik(key_enc).encrypt, 143 KUZNECHIK_BLOCKSIZE, 144 ciphertext, 145 8 * b"x00", 146 ) 147 try: 148 tbe, _ = HandshakeTBE().decode(plaintext) 149 except ASN1Error: 150 raise ValueError("can not decode TBE") 151 key_sign_pub_hash = bytes(tbe["identity"]) 152 peer = KEYS.get(key_sign_pub_hash) 153 if peer is None: 154 raise ValueError("unknown identity") 155 mac_tag = mac( 156 GOST3412Kuznechik(key_mac_identity).encrypt, 157 KUZNECHIK_BLOCKSIZE, 158 key_sign_pub_hash, 159 ) 160 if not compare_digest(mac_tag, bytes(tbe["identityMac"])): 161 raise ValueError("invalid identity MAC") 162 tbs = HandshakeTBS(( 163 ("cookieTheir", cookie_their), 164 ("cookieOur", cookie_our), 165 ("pubKeyOur", pub_key_our), 166 )) 167 if not gost3410.verify( 168 CURVE, 169 peer["pub"], 170 GOST34112012256(tbs.encode()).digest(), 171 bytes(tbe["signature"]), 172 ): 173 raise ValueError("invalid signature") 174 return peer["name"]Sezvandakanyora pamusoro, 34.13/2015/XNUMX inotsanangura zvakasiyana-siyana kubva 34.12/2015/3413. Pakati pavo pane modhi yekugadzira yekutevedzera inoisa uye MAC kuverenga. MuPyGOST iyi ndiyo gost34.12.mac(). Iyi modhi inoda kupfuudza iyo encryption basa (kugamuchira uye kudzorera imwe block yedata), saizi yevhavhavhavhavha uye, iko iko, iyo data pachayo. Sei usingakwanise hardcode saizi yeiyo encryption block? 2015/128/64 inotsanangura kwete chete XNUMX-bit Grasshopper cipher, asiwo iyo XNUMX-bit. - yakagadziridzwa zvishoma GOST 28147-89, yakagadzirwa kumashure muKGB uye ichine imwe yepamusoro-soro chengetedzo zvikumbaridzo.
Kuznechik inotangwa nekudaidza gost.3412.GOST3412Kuznechik(kiyi) uye inodzosera chinhu chine .encrypt()/.decrypt() nzira dzakakodzera kupfuudza ku34.13 mabasa. MAC inoverengwa sezvizvi: gost3413.mac(GOST3412Kuznechik(key).encrypt, KUZNECHIK_BLOCKSIZE, ciphertext). Kuenzanisa iyo yakaverengerwa uye yakagashirwa MAC, haugone kushandisa yakajairwa kuenzanisa (==) yebyte tambo, sezvo kuvhiya uku kuchiburitsa nguva yekuenzanisa, iyo, mune yakajairika, inogona kutungamirira kune ngozi inouraya senge. kurwisa TLS. Python ine basa rinokosha, hmac.compare_digest, nokuda kweizvi.
Iyo block cipher basa inogona kungovhara imwe block yedata. Kune nhamba yakakura, uye kunyange isiri yakawanda yehurefu, zvinodikanwa kushandisa encryption mode. 34.13-2015 inotsanangura zvinotevera: ECB, CTR, OFB, CBC, CFB. Imwe neimwe ine nzvimbo dzayo dzinogamuchirwa dzekushandisa uye maitiro. Nehurombo, isu hatisati tave nestandard (zvakadai seCCM, OCB, GCM nezvimwe zvakadaro) - tinomanikidzwa kuwedzera MAC isu pachedu. Ndinosarudza (CTR): haidi padding kune saizi yebhuroka, inogona kufananidzwa, inoshandisa chete encryption basa, inogona kushandiswa zvakachengeteka kuvharidzira nhamba huru dzemeseji (kusiyana neCBC, ine kudhumhana nekukurumidza).
Senge .mac(), .ctr() inotora mashoko akafanana: ciphertext = gost3413.ctr(GOST3412Kuznechik(key).encrypt, KUZNECHIK_BLOCKSIZE, plaintext, iv). Izvo zvinodikanwa kutsanangura yekutanga vector iyo inonyatso hafu yehurefu hweiyo encryption block. Kana kiyi yedu yekuvharidzira ichishandiswa chete kuvharidzira meseji imwe chete (kunyangwe kubva kune akati wandei), saka zvakachengeteka kuseta zero yekutanga vector. Kuti tivhare mameseji ekubata maoko, tinoshandisa kiyi yakaparadzana nguva yega yega.
Kuongorora siginecha gost3410.verify() hazvina basa: tinopfuura elliptic curve mukati matiri kushanda (tinongoinyora muGOSTIM protocol yedu), kiyi yeruzhinji yeanosaina (usakanganwa kuti iyi inofanira kunge iri tuple yezviviri. nhamba huru, uye kwete tambo yebyte), 34.11/2012/XNUMX hashi uye siginicha pachayo.
Tevere, mune yekutanga isu tinogadzirira uye nekutumira meseji yekubata ruoko kunobata maoko2, tichiita zvimwechetezvo sezvatakaita panguva yekusimbisa, chete symmetrically: kusaina pamakiyi edu pachinzvimbo chekutarisa, nezvimwe ...
456 # Prepare and send Handshake 2 message {{{ 457 tbs = HandshakeTBS(( 458 ("cookieTheir", cookie_their), 459 ("cookieOur", cookie_our), 460 ("pubKeyOur", pub_our_raw), 461 )) 462 signature = gost3410.sign( 463 CURVE, 464 KEY_OUR_SIGN_PRV, 465 GOST34112012256(tbs.encode()).digest(), 466 ) 467 key_handshake2_mac_identity = kdf.expand(b"handshake2-mac-identity") 468 mac_tag = mac( 469 GOST3412Kuznechik(key_handshake2_mac_identity).encrypt, 470 KUZNECHIK_BLOCKSIZE, 471 bytes(KEY_OUR_SIGN_PUB_HASH), 472 ) 473 tbe = HandshakeTBE(( 474 ("identity", KEY_OUR_SIGN_PUB_HASH), 475 ("signature", OctetString(signature)), 476 ("identityMac", MAC(mac_tag)), 477 )) 478 tbe_raw = tbe.encode() 479 key_handshake2_enc = kdf.expand(b"handshake2-enc") 480 key_handshake2_mac = kdf.expand(b"handshake2-mac") 481 ciphertext = ctr( 482 GOST3412Kuznechik(key_handshake2_enc).encrypt, 483 KUZNECHIK_BLOCKSIZE, 484 tbe_raw, 485 8 * b"x00", 486 ) 487 mac_tag = mac( 488 GOST3412Kuznechik(key_handshake2_mac).encrypt, 489 KUZNECHIK_BLOCKSIZE, 490 ciphertext, 491 ) 492 writer.write(Msg(("handshake2", MsgHandshake2(( 493 ("ciphertext", OctetString(ciphertext)), 494 ("ciphertextMac", MAC(mac_tag)), 495 )))).encode()) 496 # }}} 497 await writer.drain() 498 logging.info("%s: session established: %s", _id, peer_name)Kana iyo sesheni yatangwa, makiyi ekufambisa anogadzirwa (kiyi yakaparadzana yekuvharidzira, yekusimbisa, kune yega yega mapato), uye Grasshopper inotangwa kudhipta uye kutarisa MAC:
499 # Run text message sender, initialize transport decoder {{{ 500 key_initiator_enc = kdf.expand(b"transport-initiator-enc") 501 key_initiator_mac = kdf.expand(b"transport-initiator-mac") 502 key_responder_enc = kdf.expand(b"transport-responder-enc") 503 key_responder_mac = kdf.expand(b"transport-responder-mac") ... 509 asyncio.ensure_future(msg_sender( 510 peer_name, 511 key_initiator_enc, 512 key_initiator_mac, 513 writer, 514 )) 515 encrypter = GOST3412Kuznechik(key_responder_enc).encrypt 516 macer = GOST3412Kuznechik(key_responder_mac).encrypt 517 # }}} 519 nonce_expected = 0 520 # Wait for test messages {{{ 521 while True: 522 data = await reader.read(MaxMsgLen) ... 530 msg, tail = Msg().decode(buf) ... 537 try: 538 await msg_receiver( 539 msg.value, 540 nonce_expected, 541 macer, 542 encrypter, 543 peer_name, 544 ) 545 except ValueError as err: 546 logging.warning("%s: %s", err) 547 break 548 nonce_expected += 1 549 # }}}Iyo msg_sender coroutine ikozvino encrypts mameseji isati yaatumira paTCP yekubatanidza. Imwe neimwe meseji ine monotonically inowedzera nonce, inova zvakare yekutanga vector kana yakavharidzirwa mune counter mode. Imwe neimwe meseji uye meseji block inovimbiswa kuve neyakasiyana counter value.
async def msg_sender(peer_name: str, key_enc: bytes, key_mac: bytes, writer) -> None: nonce = 0 encrypter = GOST3412Kuznechik(key_enc).encrypt macer = GOST3412Kuznechik(key_mac).encrypt in_queue = IN_QUEUES[peer_name] while True: text = await in_queue.get() if text is None: break ciphertext = ctr( encrypter, KUZNECHIK_BLOCKSIZE, text.encode("utf-8"), long2bytes(nonce, 8), ) payload = MsgTextPayload(( ("nonce", Integer(nonce)), ("ciphertext", OctetString(ciphertext)), )) mac_tag = mac(macer, KUZNECHIK_BLOCKSIZE, payload.encode()) writer.write(Msg(("text", MsgText(( ("payload", payload), ("payloadMac", MAC(mac_tag)), )))).encode()) nonce += 1Mameseji anouya anogadziriswa ne msg_receiver coroutine, inobata chokwadi uye decryption:
async def msg_receiver( msg_text: MsgText, nonce_expected: int, macer, encrypter, peer_name: str, ) -> None: payload = msg_text["payload"] if int(payload["nonce"]) != nonce_expected: raise ValueError("unexpected nonce value") mac_tag = mac(macer, KUZNECHIK_BLOCKSIZE, payload.encode()) if not compare_digest(mac_tag, bytes(msg_text["payloadMac"])): raise ValueError("invalid MAC") plaintext = ctr( encrypter, KUZNECHIK_BLOCKSIZE, bytes(payload["ciphertext"]), long2bytes(nonce_expected, 8), ) text = plaintext.decode("utf-8") await OUT_QUEUES[peer_name].put(text)mhedziso
GOSTIM inotarisirwa kushandiswa chete nekuda kwezvinangwa zvekudzidzisa (sezvo isina kuvharwa nemiedzo, kanenge)! Iyo kodhi yekodhi yepurogiramu inogona kutorwa (Π‘ΡΡΠΈΠ±ΠΎΠ³-256 Ρ ΡΡ: 995bbd368c04e50a481d138c5fa2e43ec7c89bc77743ba8dbabee1fde45de120). ΠΠ°ΠΊ ΠΈ Π²ΡΠ΅ ΠΌΠΎΠΈ ΠΏΡΠΎΠ΅ΠΊΡΡ, ΡΠΈΠΏΠ° , , , , GOSTIM zvachose , yakagoverwa pasi pemitemo .
, , nhengo , Python/Go mugadziri, nyanzvi huru .
Source: www.habr.com