def locate_pack_recipient_key(recipients: Sequence[dict], my_verkey: bytes,
my_sigkey: bytes) -> (bytes, str, str):
"""
Locate pack recipient key.
Decode the encryption key and sender verification key from a
corresponding recipient block, if any is defined.
Args:
recipients: Recipients to locate
find_key: Function used to find private key
Returns:
A tuple of (cek, sender_vk, recip_vk_b58)
Raises:
ValueError: If no corresponding recipient key found
"""
not_found = []
for recip in recipients:
if not recip or "header" not in recip or "encrypted_key" not in recip:
raise ValueError("Invalid recipient header")
recip_vk_b58 = recip["header"].get("kid")
if bytes_to_b58(my_verkey) != recip_vk_b58:
not_found.append(recip_vk_b58)
continue
recip_vk = b58_to_bytes(recip_vk_b58)
pk = pysodium.crypto_sign_pk_to_box_pk(my_verkey)
sk = pysodium.crypto_sign_sk_to_box_sk(my_sigkey)
encrypted_key = b64_to_bytes(recip["encrypted_key"], urlsafe=True)
nonce_b64 = recip["header"].get("iv")
nonce = b64_to_bytes(nonce_b64, urlsafe=True) if nonce_b64 else None
sender_b64 = recip["header"].get("sender")
enc_sender = b64_to_bytes(sender_b64,
urlsafe=True) if sender_b64 else None
if nonce and enc_sender:
sender_vk_bin = pysodium.crypto_box_seal_open(enc_sender, pk, sk)
sender_vk = sender_vk_bin.decode("ascii")
sender_pk = pysodium.crypto_sign_pk_to_box_pk(
b58_to_bytes(sender_vk_bin))
cek = pysodium.crypto_box_open(encrypted_key, nonce, sender_pk, sk)
else:
sender_vk = None
cek = pysodium.crypto_box_seal_open(encrypted_key, pk, sk)
return cek, sender_vk, recip_vk_b58
raise ValueError(
"No corresponding recipient key found in {}".format(not_found))
def handle(self):
data, socket = self.request
unsealed = pysodium.crypto_box_seal_open(data, pk, sk)
ap = unsealed[:pysodium.crypto_box_PUBLICKEYBYTES]
challenge = unsealed[pysodium.crypto_box_PUBLICKEYBYTES:]
packets.append(ap)
nonce = pysodium.randombytes(pysodium.crypto_box_NONCEBYTES)
response = pysodium.crypto_box(challenge, nonce, ap, sk)
dst = (src2dst(self.client_address[0]), REG_PORT)
socket.setsockopt(SOL_SOCKET, SO_BROADCAST, 1)
socket.sendto(nonce + response, dst)
def decrypt_news(news_item):
assert ('to' in news_item)
# Message was sent to a team, so we need to decode and decrypt it
decoded_msg = b64decode(news_item['msg'].encode("utf-8"))
try:
team_pk, team_sk = team['crypt_pk'], TeamSecrets['crypt_sk']
decrypted_msg = pysodium.crypto_box_seal_open(
decoded_msg, team_pk, team_sk)
except:
decrypted_msg = b'<Failed to decrypt>'
news_item['msg'] = decrypted_msg.decode("utf-8")
return news_item
def test0():
if not pysodium.sodium_version_check(1, 0, 9): return
pk, sk = pysodium.crypto_box_keypair()
#print(pk)
#print(sk)
p = binascii.hexlify(pk)
s = binascii.hexlify(sk)
print(p)
print(s)
c = pysodium.crypto_box_seal(b"passwd", pk)
print(binascii.hexlify(c))
print(pysodium.crypto_box_seal_open(c, pk, sk))
def decrypt_report(self, encrypted_report_blob):
"""
Decrypt a report blob using libnacl public encryption or throw
an exception if in case there is a problem with decryption
Args:
report: The report as json string in base64 encoding
Returns:
The original report.
"""
return pysodium.crypto_box_seal_open(
base64.decodestring(encrypted_report_blob), self.receiver_pub_key,
self.receiver_secret_key)
def anon_decrypt_message(enc_message: bytes, secret: bytes) -> bytes:
"""
Apply anon_decrypt to a binary message.
Args:
enc_message: The encrypted message
secret: The seed to use
Returns:
The decrypted message
"""
sign_pk, sign_sk = create_keypair(secret)
pk = pysodium.crypto_sign_pk_to_box_pk(sign_pk)
sk = pysodium.crypto_sign_sk_to_box_sk(sign_sk)
message = pysodium.crypto_box_seal_open(enc_message, pk, sk)
return message
def data_received(self, data):
if verbose: print('Data received: ', data, file=sys.stderr)
try:
data = pysodium.crypto_sign_open(data, self.handler.getserverkey())
except ValueError:
raise ValueError('invalid signature.\nabort')
if data != b'ok' and (data[:-42] == b'fail' or
len(data) != sphinxlib.DECAF_255_SER_BYTES + 90):
raise ValueError('fail')
if not self.b:
self.cb()
return
rwd = sphinxlib.finish(self.pwd, self.b,
data[:sphinxlib.DECAF_255_SER_BYTES])
if self.handler.namesite is not None:
if self.handler.namesite['name'].encode() not in self.handler.list(
self.handler.namesite['site']):
self.handler.cacheuser(self.handler.namesite)
rule = data[sphinxlib.DECAF_255_SER_BYTES:]
esk = self.handler.getkey()
sk = pysodium.crypto_sign_sk_to_box_sk(esk)
epk = pysodium.crypto_sign_sk_to_pk(esk)
pk = pysodium.crypto_sign_pk_to_box_pk(epk)
rule = pysodium.crypto_box_seal_open(rule, pk, sk)
if len(rule) != 42:
raise ValueError('fail')
rk = pysodium.crypto_generichash(self.handler.getkey(),
self.handler.getsalt())
rule = pysodium.crypto_secretbox_open(rule[24:], rule[:24], rk)
rule = struct.unpack(">H", rule)[0]
size = (rule & 0x7f)
rule = {
c
for i, c in enumerate(('u', 'l', 's', 'd'))
if (rule >> 7) & (1 << i)
}
self.cb(bin2pass.derive(rwd, rule, size).decode())
def test_box_seal():
#p1 = b'~\x8b8\xf0%\xef\xba\x86\xe6\xcd\xd8\x16\x8b,\xf7\xa9\xc7a@F\x08\x84sx6\x1c\x18\xf5\x03\xbd"\x05'
#s1 = b'\xe1\xa2\xfd\xc0\xbb\xe9\x1f,\x8a\xe8)D\x1dII\xe0\x9e{\xf1\xbe0\x04\x04\x8c\xde9V\x97\x9f\xe5&\x1a'
pk_s = '7e8b38f025efba86e6cdd8168b2cf7a9c761404608847378361c18f503bd2205'
sk_s = 'e1a2fdc0bbe91f2c8ae829441d4949e09e7bf1be3004048cde3956979fe5261a'
# string to bytes (hexadecimal )
pk_h = bytes(pk_s, 'utf8')
sk_h = bytes(sk_s, 'utf8')
# hexadecimal to binary data
pk_b = binascii.unhexlify(pk_h)
sk_b = binascii.unhexlify(sk_h)
x_s = '1f4fa3ccb8d877a7c8a26d4c86c6866eba50c8ad03567ac7e6f84cff3069e97e7576bc506c55de41501419fd49dadd13755b426b018d'
x_b = bytes(x_s, 'utf8')
s = binascii.unhexlify(x_b)
print(pysodium.crypto_box_seal_open(s, pk_b, sk_b))
def data_received(self, data):
res = b''
if verbose:
print('Data received: {!r}'.format(data))
esk, xsk, xpk = getkey(keydir)
data = pysodium.crypto_box_seal_open(data, xpk, xsk)
clearmem(xsk)
if data[64] == 0:
res = self.create(data)
elif data[64] == GET:
# needs id, challenge, sig(id)
# returns output from ./response | fail
res = self.get(data)
elif data[64] == CHANGE:
# needs id, challenge, sig(id)
# changes stored secret
# returns output from ./response | fail
res = self.change(data)
elif data[64] == DELETE:
# needs id, sig(id)
# returns ok|fail
res = self.delete(data)
elif data[64] == COMMIT:
# needs id, sig(id)
# returns ok|fail
res = self.commit(data)
if verbose:
print('Send: {!r}'.format(res))
res = pysodium.crypto_sign(res, esk)
clearmem(esk)
self.transport.write(res)
if verbose:
print('Close the client socket')
self.transport.close()
def auth_decrypt_message(enc_message: bytes, my_verkey: bytes,
my_sigkey: bytes) -> (bytes, str):
"""
Apply auth_decrypt to a binary message.
Args:
enc_message: The encrypted message
secret: Secret for signing keys
Returns:
A tuple of (decrypted message, sender verkey)
"""
pk = pysodium.crypto_sign_pk_to_box_pk(my_verkey)
sk = pysodium.crypto_sign_sk_to_box_sk(my_sigkey)
body = pysodium.crypto_box_seal_open(enc_message, pk, sk)
unpacked = msgpack.unpackb(body, raw=False)
sender_vk = unpacked["sender"]
nonce = b64_to_bytes(unpacked["nonce"])
enc_message = b64_to_bytes(unpacked["msg"])
sender_pk = pysodium.crypto_sign_pk_to_box_pk(b58_to_bytes(sender_vk))
message = pysodium.crypto_box_open(enc_message, nonce, sender_pk, sk)
return message, sender_vk
def test_crypto_box_seal(self):
pk, sk = pysodium.crypto_box_keypair()
c = pysodium.crypto_box_seal(b"howdy", pk)
self.assertEqual(pysodium.crypto_box_seal_open(c, pk, sk), b'howdy')
def test_crypto_box_seal(self):
if not pysodium.sodium_version_check(1, 0, 3): return
pk, sk = pysodium.crypto_box_keypair()
c = pysodium.crypto_box_seal(b"howdy", pk)
self.assertEqual(pysodium.crypto_box_seal_open(c, pk, sk), b'howdy')
def test_pysodium():
"""
Test all the functions needed from pysodium libarary (libsodium)
"""
# crypto_sign signatures with Ed25519 keys
# create keypair without seed
verkey, sigkey = pysodium.crypto_sign_keypair()
assert len(verkey) == 32 == pysodium.crypto_sign_PUBLICKEYBYTES
assert len(sigkey) == 64 == pysodium.crypto_sign_SECRETKEYBYTES
assert 32 == pysodium.crypto_sign_SEEDBYTES
sigseed = pysodium.randombytes(pysodium.crypto_sign_SEEDBYTES)
assert len(sigseed) == 32
# seed = (b'J\xeb\x06\xf2BA\xd6/T\xe1\xe2\xe2\x838\x8a\x99L\xd9\xb5(\\I\xccRb\xc8\xd5\xc7Y\x1b\xb6\xf0')
# Ann's seed
sigseed = (
b'PTi\x15\xd5\xd3`\xf1u\x15}^r\x9bfH\x02l\xc6\x1b\x1d\x1c\x0b9\xd7{\xc0_\xf2K\x93`'
)
assert len(sigseed) == 32
# try key stretching from 16 bytes using pysodium.crypto_pwhash()
assert 16 == pysodium.crypto_pwhash_SALTBYTES
salt = pysodium.randombytes(pysodium.crypto_pwhash_SALTBYTES)
assert len(salt) == 16
# salt = b'\x19?\xfa\xc7\x8f\x8b\x7f\x8b\xdbS"$\xd7[\x85\x87'
# algorithm default is argon2id
sigseed = pysodium.crypto_pwhash(
outlen=32,
passwd="",
salt=salt,
opslimit=pysodium.crypto_pwhash_OPSLIMIT_INTERACTIVE,
memlimit=pysodium.crypto_pwhash_MEMLIMIT_INTERACTIVE,
alg=pysodium.crypto_pwhash_ALG_DEFAULT)
assert len(sigseed) == 32
# seed = (b'\xa9p\x89\x7f+\x0e\xc4\x9c\xf2\x01r\xafTI\xc0\xfa\xac\xd5\x99\xf8O\x8f=\x843\xa2\xb6e\x9fO\xff\xd0')
# creates signing/verification key pair from seed
verkey, sigkey = pysodium.crypto_sign_seed_keypair(sigseed)
assert len(verkey) == 32
assert len(sigkey) == 64
# sigkey is seed and verkey concatenated. Libsodium does this as an optimization
# because the signing scheme needs both the private key (seed) and the public key so
# instead of recomputing the public key each time from the secret key it requires
# the public key as an input of and instead of two separate inputs, one for the
# secret key and one for the public key, it uses a concatenated form.
# Essentially crypto_sign_seed_keypair and crypto_sign_keypair return redundant
# information in the duple (verkey, sigkey) because sigkey includes verkey
# so one could just store sigkey and extract verkey or sigseed when needed
# or one could just store verkey and sigseed and reconstruct sigkey when needed.
# crypto_sign_detached requires sigkey (sigseed + verkey)
# crypto_sign_verify_detached reqires verkey only
# https://crypto.stackexchange.com/questions/54353/why-are-nacl-secret-keys-64-bytes-for-signing-but-32-bytes-for-box
assert sigseed == sigkey[:32]
assert verkey == sigkey[32:]
assert sigkey == sigseed + verkey
# vk = (b'B\xdd\xbb}8V\xa0\xd6lk\xcf\x15\xad9\x1e\xa7\xa1\xfe\xe0p<\xb6\xbex\xb0s\x8d\xd6\xf5\xa5\xe8Q')
# utility function to extract seed from secret sigkey (really just extracting from front half)
assert sigseed == pysodium.crypto_sign_sk_to_seed(sigkey)
assert 64 == pysodium.crypto_sign_BYTES
msg = "The lazy dog jumped over the river"
msgb = msg.encode(
"utf-8") # must convert unicode string to bytes in order to sign it
assert msgb == b'The lazy dog jumped over the river'
sig = pysodium.crypto_sign_detached(msgb, sigseed +
verkey) # sigkey = seed + verkey
assert len(sig) == 64
"""
sig = (b"\x99\xd2<9$$0\x9fk\xfb\x18\xa0\x8c@r\x122.k\xb2\xc7\x1fp\x0e'm\x8f@"
b'\xaa\xa5\x8c\xc8n\x85\xc8!\xf6q\x91p\xa9\xec\xcf\x92\xaf)\xde\xca'
b'\xfc\x7f~\xd7o|\x17\x82\x1d\xd4<o"\x81&\t')
"""
#siga = pysodium.crypto_sign(msg.encode("utf-8"), sk)[:pysodium.crypto_sign_BYTES]
#assert len(siga) == 64
#assert sig == siga
try: # verify returns None if valid else raises ValueError
result = pysodium.crypto_sign_verify_detached(sig, msgb, verkey)
except Exception as ex:
assert False
assert not result
assert result is None
sigbad = sig[:-1]
sigbad += b'A'
try: # verify returns None if valid else raises ValueError
result = pysodium.crypto_sign_verify_detached(sigbad, msgb, verkey)
except Exception as ex:
assert True
assert isinstance(ex, ValueError)
# crypto_box authentication encryption with X25519 keys
apubkey, aprikey = pysodium.crypto_box_keypair()
assert len(apubkey) == 32 == pysodium.crypto_box_SECRETKEYBYTES
assert len(aprikey) == 32 == pysodium.crypto_box_PUBLICKEYBYTES
repubkey = pysodium.crypto_scalarmult_curve25519_base(aprikey)
assert repubkey == apubkey
assert 32 == pysodium.crypto_box_SEEDBYTES
boxseed = pysodium.randombytes(pysodium.crypto_box_SEEDBYTES)
assert len(boxseed) == 32
bpubkey, bprikey = pysodium.crypto_box_seed_keypair(boxseed)
assert len(bpubkey) == 32
assert len(bprikey) == 32
repubkey = pysodium.crypto_scalarmult_curve25519_base(bprikey)
assert repubkey == bpubkey
assert 24 == pysodium.crypto_box_NONCEBYTES
nonce = pysodium.randombytes(pysodium.crypto_box_NONCEBYTES)
assert len(nonce) == 24
# nonce = b'\x11\xfbi<\xf2\xb6k\xa05\x0c\xf9\x86t\x07\x8e\xab\x8a\x97nG\xe8\x87,\x94'
atob_tx = "Hi Bob I'm Alice"
atob_txb = atob_tx.encode("utf-8")
# Detached recomputes shared key every time.
# A encrypt to B
acrypt, amac = pysodium.crypto_box_detached(atob_txb, nonce, bpubkey,
aprikey)
amacl = pysodium.crypto_box_MACBYTES
assert amacl == 16
# amac = b'\xa1]\xc6ML\xe2\xa9:\xc0\xdc\xab\xa5\xc4\xc7\xf4\xdb'
# acrypt = (b'D\n\x17\xb6z\xd8+t)\xcc`y\x1d\x10\x0cTC\x02\xb5@\xe2\xf2\xc9-(\xec*O\xb8~\xe2\x1a\xebO')
# when transmitting prepend amac to crypt
acipher = pysodium.crypto_box(atob_txb, nonce, bpubkey, aprikey)
assert acipher == amac + acrypt
atob_rxb = pysodium.crypto_box_open_detached(acrypt, amac, nonce, apubkey,
bprikey)
atob_rx = atob_rxb.decode("utf-8")
assert atob_rx == atob_tx
assert atob_rxb == atob_txb
atob_rxb = pysodium.crypto_box_open(acipher, nonce, apubkey, bprikey)
atob_rx = atob_rxb.decode("utf-8")
assert atob_rx == atob_tx
assert atob_rxb == atob_txb
btoa_tx = "Hello Alice I am Bob"
btoa_txb = btoa_tx.encode("utf-8")
# B encrypt to A
bcrypt, bmac = pysodium.crypto_box_detached(btoa_txb, nonce, apubkey,
bprikey)
# bmac = b'\x90\xe07=\xd22\x8fh2\xff\xdd\x84tC\x053'
# bcrypt = (b'8\xb5\xba\xe7\xcc\xae B\xefx\xe6{U\xf7\xefA\x00\xc7|\xdbu\xcfc\x01$\xa9\xa2P\xa7\x84\xa5\xae\x180')
# when transmitting prepend amac to crypt
bcipher = pysodium.crypto_box(btoa_txb, nonce, apubkey, bprikey)
assert bcipher == bmac + bcrypt
btoa_rxb = pysodium.crypto_box_open_detached(bcrypt, bmac, nonce, bpubkey,
aprikey)
btoa_rx = btoa_rxb.decode("utf-8")
assert btoa_rx == btoa_tx
assert btoa_rxb == btoa_txb
btoa_rxb = pysodium.crypto_box_open(bcipher, nonce, bpubkey, aprikey)
btoa_rx = btoa_rxb.decode("utf-8")
assert btoa_rx == btoa_tx
assert btoa_rxb == btoa_txb
# compute shared key
asymkey = pysodium.crypto_box_beforenm(bpubkey, aprikey)
bsymkey = pysodium.crypto_box_beforenm(apubkey, bprikey)
assert asymkey == bsymkey
acipher = pysodium.crypto_box_afternm(atob_txb, nonce, asymkey)
atob_rxb = pysodium.crypto_box_open_afternm(acipher, nonce, bsymkey)
assert atob_rxb == atob_txb
bcipher = pysodium.crypto_box_afternm(btoa_txb, nonce, bsymkey)
btoa_rxb = pysodium.crypto_box_open_afternm(bcipher, nonce, asymkey)
assert btoa_rxb == btoa_txb
# crypto_box_seal public key encryption with X25519 keys
# uses same X25519 type of keys as crypto_box authenticated encryption
# so when converting sign key Ed25519 to X25519 can use for both types of encryption
pubkey, prikey = pysodium.crypto_box_keypair()
assert len(pubkey) == 32 == pysodium.crypto_box_PUBLICKEYBYTES
assert len(prikey) == 32 == pysodium.crypto_box_SECRETKEYBYTES
assert 48 == pysodium.crypto_box_SEALBYTES
msg_txb = "Catch me if you can.".encode("utf-8")
assert msg_txb == b'Catch me if you can.'
cipher = pysodium.crypto_box_seal(msg_txb, pubkey)
assert len(cipher) == 48 + len(msg_txb)
msg_rxb = pysodium.crypto_box_seal_open(cipher, pubkey, prikey)
assert msg_rxb == msg_txb
# convert Ed25519 key pair to X25519 key pair
# https://blog.filippo.io/using-ed25519-keys-for-encryption/
# https://libsodium.gitbook.io/doc/advanced/ed25519-curve25519
# crypto_sign_ed25519_pk_to_curve25519
# crypto_sign_ed25519_sk_to_curve25519
pubkey = pysodium.crypto_sign_pk_to_box_pk(verkey)
assert len(pubkey) == pysodium.crypto_box_PUBLICKEYBYTES
prikey = pysodium.crypto_sign_sk_to_box_sk(sigkey)
assert len(prikey) == pysodium.crypto_box_SECRETKEYBYTES
repubkey = pysodium.crypto_scalarmult_curve25519_base(prikey)
assert repubkey == pubkey
msg_txb = "Encoded using X25519 key converted from Ed25519 key".encode(
"utf-8")
cipher = pysodium.crypto_box_seal(msg_txb, pubkey)
assert len(cipher) == 48 + len(msg_txb)
msg_rxb = pysodium.crypto_box_seal_open(cipher, pubkey, prikey)
assert msg_rxb == msg_txb
"""
def test_crypto_box_seal(self):
if not pysodium.sodium_version_check(1, 0, 3): return
pk, sk = pysodium.crypto_box_keypair()
c = pysodium.crypto_box_seal(b"howdy", pk)
self.assertEqual(pysodium.crypto_box_seal_open(c, pk, sk), b'howdy')
def decrypt_msg(msg):
team_pk, team_sk = team['crypt_pk'], TeamSecrets['crypt_sk']
# TODO Check if that's the better approach
# reference: https://download.libsodium.org/doc/public-key_cryptography/sealed_boxes.html
return pysodium.crypto_box_seal_open(msg, team_pk, team_sk)
def test_crypto_box_seal(self):
pk, sk = pysodium.crypto_box_keypair()
c = pysodium.crypto_box_seal(b"howdy", pk)
self.assertEqual(pysodium.crypto_box_seal_open(c, pk, sk), b'howdy')
