def crypto_box(message, nonce, pk, sk):
"""
Encrypts and returns a message ``message`` using the secret key ``sk``,
public key ``pk``, and the nonce ``nonce``.
:param message: bytes
:param nonce: bytes
:param pk: bytes
:param sk: bytes
:rtype: bytes
"""
if len(nonce) != crypto_box_NONCEBYTES:
raise ValueError("Invalid nonce size")
if len(pk) != crypto_box_PUBLICKEYBYTES:
raise ValueError("Invalid public key")
if len(sk) != crypto_box_SECRETKEYBYTES:
raise ValueError("Invalid secret key")
padded = (b"\x00" * crypto_box_ZEROBYTES) + message
ciphertext = ffi.new("unsigned char[]", len(padded))
rc = lib.crypto_box(ciphertext, padded, len(padded), nonce, pk, sk)
ensure(rc == 0,
'Unexpected library error',
raising=exc.RuntimeError)
return ffi.buffer(ciphertext, len(padded))[crypto_box_BOXZEROBYTES:]
def crypto_box_open(ciphertext, nonce, pk, sk):
"""
Decrypts and returns an encrypted message ``ciphertext``, using the secret
key ``sk``, public key ``pk``, and the nonce ``nonce``.
:param ciphertext: bytes
:param nonce: bytes
:param pk: bytes
:param sk: bytes
:rtype: bytes
"""
if len(nonce) != crypto_box_NONCEBYTES:
raise ValueError("Invalid nonce size")
if len(pk) != crypto_box_PUBLICKEYBYTES:
raise ValueError("Invalid public key")
if len(sk) != crypto_box_SECRETKEYBYTES:
raise ValueError("Invalid secret key")
padded = (b"\x00" * crypto_box_BOXZEROBYTES) + ciphertext
plaintext = ffi.new("unsigned char[]", len(padded))
res = lib.crypto_box_open(plaintext, padded, len(padded), nonce, pk, sk)
ensure(res == 0, "An error occurred trying to decrypt the message",
raising=exc.CryptoError)
return ffi.buffer(plaintext, len(padded))[crypto_box_ZEROBYTES:]
def crypto_box_open_afternm(ciphertext, nonce, k):
"""
Decrypts and returns the encrypted message ``ciphertext``, using the shared
key ``k`` and the nonce ``nonce``.
:param ciphertext: bytes
:param nonce: bytes
:param k: bytes
:rtype: bytes
"""
if len(nonce) != crypto_box_NONCEBYTES:
raise ValueError("Invalid nonce")
if len(k) != crypto_box_BEFORENMBYTES:
raise ValueError("Invalid shared key")
padded = (b"\x00" * crypto_box_BOXZEROBYTES) + ciphertext
plaintext = ffi.new("unsigned char[]", len(padded))
res = lib.crypto_box_open_afternm(
plaintext, padded, len(padded), nonce, k)
ensure(res == 0, "An error occurred trying to decrypt the message",
raising=exc.CryptoError)
return ffi.buffer(plaintext, len(padded))[crypto_box_ZEROBYTES:]
def crypto_secretbox_open(ciphertext, nonce, key):
"""
Decrypt and returns the encrypted message ``ciphertext`` with the secret
``key`` and the nonce ``nonce``.
:param ciphertext: bytes
:param nonce: bytes
:param key: bytes
:rtype: bytes
"""
if len(key) != crypto_secretbox_KEYBYTES:
raise ValueError("Invalid key")
if len(nonce) != crypto_secretbox_NONCEBYTES:
raise ValueError("Invalid nonce")
padded = b"\x00" * crypto_secretbox_BOXZEROBYTES + ciphertext
plaintext = ffi.new("unsigned char[]", len(padded))
res = lib.crypto_secretbox_open(
plaintext, padded, len(padded), nonce, key)
ensure(res == 0, "Decryption failed. Ciphertext failed verification",
raising=exc.CryptoError)
plaintext = ffi.buffer(plaintext, len(padded))
return plaintext[crypto_secretbox_ZEROBYTES:]
def crypto_box_afternm(message, nonce, k):
"""
Encrypts and returns the message ``message`` using the shared key ``k`` and
the nonce ``nonce``.
:param message: bytes
:param nonce: bytes
:param k: bytes
:rtype: bytes
"""
if len(nonce) != crypto_box_NONCEBYTES:
raise ValueError("Invalid nonce")
if len(k) != crypto_box_BEFORENMBYTES:
raise ValueError("Invalid shared key")
padded = b"\x00" * crypto_box_ZEROBYTES + message
ciphertext = ffi.new("unsigned char[]", len(padded))
rc = lib.crypto_box_afternm(ciphertext, padded, len(padded), nonce, k)
ensure(rc == 0,
'Unexpected library error',
raising=exc.RuntimeError)
return ffi.buffer(ciphertext, len(padded))[crypto_box_BOXZEROBYTES:]
def crypto_pwhash_scryptsalsa208sha256_str(
passwd,
opslimit=SCRYPT_OPSLIMIT_INTERACTIVE,
memlimit=SCRYPT_MEMLIMIT_INTERACTIVE):
"""
Derive a cryptographic key using the ``passwd`` and ``salt``
given as input, returning a string representation which includes
the salt and the tuning parameters.
The returned string can be directly stored as a password hash.
See :py:func:`.crypto_pwhash_scryptsalsa208sha256` for a short
discussion about ``opslimit`` and ``memlimit`` values.
:param bytes passwd:
:param int opslimit:
:param int memlimit:
:return: serialized key hash, including salt and tuning parameters
:rtype: bytes
"""
buf = ffi.new("char[]", SCRYPT_STRBYTES)
ret = lib.crypto_pwhash_scryptsalsa208sha256_str(buf, passwd, len(passwd),
opslimit, memlimit)
ensure(ret == 0,
'Unexpected failure in password hashing',
raising=exc.RuntimeError)
return ffi.string(buf)
def crypto_secretbox_open(ciphertext, nonce, key):
"""
Decrypt and returns the encrypted message ``ciphertext`` with the secret
``key`` and the nonce ``nonce``.
:param ciphertext: bytes
:param nonce: bytes
:param key: bytes
:rtype: bytes
"""
if len(key) != crypto_secretbox_KEYBYTES:
raise ValueError("Invalid key")
if len(nonce) != crypto_secretbox_NONCEBYTES:
raise ValueError("Invalid nonce")
padded = b"\x00" * crypto_secretbox_BOXZEROBYTES + ciphertext
plaintext = ffi.new("unsigned char[]", len(padded))
res = lib.crypto_secretbox_open(plaintext, padded, len(padded), nonce, key)
ensure(res == 0,
"Decryption failed. Ciphertext failed verification",
raising=exc.CryptoError)
plaintext = ffi.buffer(plaintext, len(padded))
return plaintext[crypto_secretbox_ZEROBYTES:]
def crypto_hash_sha512(message):
"""
Hashes and returns the message ``message``.
:param message: bytes
:rtype: bytes
"""
digest = ffi.new("unsigned char[]", crypto_hash_sha512_BYTES)
rc = lib.crypto_hash_sha512(digest, message, len(message))
ensure(rc == 0, 'Unexpected library error', raising=exc.RuntimeError)
return ffi.buffer(digest, crypto_hash_sha512_BYTES)[:]
def crypto_hash_sha512(message):
"""
Hashes and returns the message ``message``.
:param message: bytes
:rtype: bytes
"""
digest = ffi.new("unsigned char[]", crypto_hash_sha512_BYTES)
rc = lib.crypto_hash_sha512(digest, message, len(message))
ensure(rc == 0,
'Unexpected library error',
raising=exc.RuntimeError)
return ffi.buffer(digest, crypto_hash_sha512_BYTES)[:]
def crypto_scalarmult_base(n):
"""
Computes and returns the scalar product of a standard group element and an
integer ``n``.
:param n: bytes
:rtype: bytes
"""
q = ffi.new("unsigned char[]", crypto_scalarmult_BYTES)
rc = lib.crypto_scalarmult_base(q, n)
ensure(rc == 0, 'Unexpected library error', raising=exc.RuntimeError)
return ffi.buffer(q, crypto_scalarmult_SCALARBYTES)[:]
def generichash_blake2b_salt_personal(data,
digest_size=crypto_generichash_BYTES,
key=b'',
salt=b'',
person=b''):
"""One shot hash interface
:param data: the input data to the hash function
:param digest_size: must be at most
:py:data:`.crypto_generichash_BYTES_MAX`;
the default digest size is
:py:data:`.crypto_generichash_BYTES`
:type digest_size: int
:param key: must be at most
:py:data:`.crypto_generichash_KEYBYTES_MAX` long
:type key: bytes
:param salt: must be at most
:py:data:`.crypto_generichash_SALTBYTES` long;
will be zero-padded if needed
:type salt: bytes
:param person: must be at most
:py:data:`.crypto_generichash_PERSONALBYTES` long:
will be zero-padded if needed
:type person: bytes
:return: digest_size long digest
:rtype: bytes
"""
_checkparams(digest_size, key, salt, person)
ensure(isinstance(data, bytes),
'Input data must be a bytes sequence',
raising=exc.TypeError)
digest = ffi.new("unsigned char[]", digest_size)
# both _salt and _personal must be zero-padded to the correct length
_salt = ffi.new("unsigned char []", crypto_generichash_SALTBYTES)
_person = ffi.new("unsigned char []", crypto_generichash_PERSONALBYTES)
ffi.memmove(_salt, salt, len(salt))
ffi.memmove(_person, person, len(person))
rc = lib.crypto_generichash_blake2b_salt_personal(digest, digest_size,
data, len(data), key,
len(key), _salt, _person)
ensure(rc == 0, 'Unexpected failure', raising=exc.RuntimeError)
return ffi.buffer(digest, digest_size)[:]
def crypto_shorthash_siphash24(data, key):
"""Compute a fast, cryptographic quality, keyed hash of the input data
:param data:
:type data: bytes
:param key: len(key) must be equal to
:py:data:`.KEYBYTES` (16)
:type key: bytes
"""
if len(key) != KEYBYTES:
raise ValueError("Key length must be {0} bytes".format(KEYBYTES))
digest = ffi.new("unsigned char[]", BYTES)
rc = lib.crypto_shorthash_siphash24(digest, data, len(data), key)
utils.ensure(rc == 0, raising=exc.RuntimeError)
return ffi.buffer(digest, BYTES)[:]
def generichash_blake2b_update(statebuf, data):
"""Update the blake2b hash state
:param statebuf: an initialized blake2b state buffer as returned from
:py:func:`.crypto_generichash_blake2b_init`
:type name: bytes
:param data:
:type data: bytes
"""
ensure(isinstance(data, bytes),
'Input data must be a bytes sequence',
raising=exc.TypeError)
rc = lib.crypto_generichash_blake2b_update(statebuf, data, len(data))
ensure(rc == 0, 'Unexpected failure', raising=exc.RuntimeError)
def generichash_blake2b_final(statebuf, digest_size):
"""Finalize the blake2b hash state and return the digest.
:param statebuf:
:type statebuf: bytes
:param digest_size:
:type digest_size: int
:return: the blake2 digest of the passed-in data stream
:rtype: bytes
"""
_digest = ffi.new("unsigned char[]", crypto_generichash_BYTES_MAX)
rc = lib.crypto_generichash_blake2b_final(statebuf, _digest, digest_size)
ensure(rc == 0, 'Unexpected failure', raising=exc.RuntimeError)
return ffi.buffer(_digest, digest_size)[:]
def crypto_scalarmult_base(n):
"""
Computes and returns the scalar product of a standard group element and an
integer ``n``.
:param n: bytes
:rtype: bytes
"""
q = ffi.new("unsigned char[]", crypto_scalarmult_BYTES)
rc = lib.crypto_scalarmult_base(q, n)
ensure(rc == 0,
'Unexpected library error',
raising=exc.RuntimeError)
return ffi.buffer(q, crypto_scalarmult_SCALARBYTES)[:]
def verify_scryptsalsa208sha256(password_hash, password):
"""
Takes the output of scryptsalsa208sha256 and compares it against
a user provided password to see if they are the same
:param password_hash: bytes
:param password: bytes
:rtype: boolean
"""
ensure(len(password_hash) == SCRYPT_PWHASH_SIZE,
"The pw_hash must be exactly %s bytes long" %
nacl.bindings.crypto_pwhash_scryptsalsa208sha256_STRBYTES,
raising=exc.ValueError)
return nacl.bindings.crypto_pwhash_scryptsalsa208sha256_str_verify(
password_hash, password)
def kdf_scryptsalsa208sha256(size,
password,
salt,
opslimit=SCRYPT_OPSLIMIT_SENSITIVE,
memlimit=SCRYPT_MEMLIMIT_SENSITIVE,
encoder=nacl.encoding.RawEncoder):
"""
Makes a key defined from ``password`` and ``salt`` that is
``size`` bytes long
the enclosing module provides the constants
- :py:const:`.SCRYPT_OPSLIMIT_INTERACTIVE`
- :py:const:`.SCRYPT_MEMLIMIT_INTERACTIVE`
- :py:const:`.SCRYPT_OPSLIMIT_SENSITIVE`
- :py:const:`.SCRYPT_MEMLIMIT_SENSITIVE`
as a guidance for correct settings respectively for the
interactive login and the long term key protecting sensitive data
use cases.
:param int size: int
:param bytes password: bytes
:param bytes salt: bytes
:param int opslimit:
:param int memlimit:
:rtype: bytes
"""
ensure(len(salt) == SCRYPT_SALTBYTES,
"The salt must be exactly %s, not %s bytes long" %
(SCRYPT_SALTBYTES, len(salt)),
raising=exc.ValueError)
n_log2, r, p = nacl.bindings.nacl_bindings_pick_scrypt_params(
opslimit, memlimit)
maxmem = memlimit + (2**16)
return encoder.encode(
nacl.bindings.crypto_pwhash_scryptsalsa208sha256_ll(password,
salt,
2**n_log2,
r,
p,
maxmem=maxmem,
dklen=size))
def crypto_sign(message, sk):
"""
Signs the message ``message`` using the secret key ``sk`` and returns the
signed message.
:param message: bytes
:param sk: bytes
:rtype: bytes
"""
signed = ffi.new("unsigned char[]", len(message) + crypto_sign_BYTES)
signed_len = ffi.new("unsigned long long *")
rc = lib.crypto_sign(signed, signed_len, message, len(message), sk)
ensure(rc == 0,
'Unexpected library error',
raising=exc.RuntimeError)
return ffi.buffer(signed, signed_len[0])[:]
def crypto_box_keypair():
"""
Returns a randomly generated public and secret key.
:rtype: (bytes(public_key), bytes(secret_key))
"""
pk = ffi.new("unsigned char[]", crypto_box_PUBLICKEYBYTES)
sk = ffi.new("unsigned char[]", crypto_box_SECRETKEYBYTES)
rc = lib.crypto_box_keypair(pk, sk)
ensure(rc == 0,
'Unexpected library error',
raising=exc.RuntimeError)
return (
ffi.buffer(pk, crypto_box_PUBLICKEYBYTES)[:],
ffi.buffer(sk, crypto_box_SECRETKEYBYTES)[:],
)
def crypto_pwhash_scryptsalsa208sha256_str_verify(passwd_hash, passwd):
"""
Verifies the ``passwd`` against the ``passwd_hash`` that was generated.
Returns True or False depending on the success
:param passwd_hash: bytes
:param passwd: bytes
:rtype: boolean
"""
ensure(len(passwd_hash) == SCRYPT_STRBYTES - 1,
'Invalid password hash',
raising=exc.ValueError)
ret = lib.crypto_pwhash_scryptsalsa208sha256_str_verify(
passwd_hash, passwd, len(passwd))
ensure(ret == 0, "Wrong password", raising=exc.InvalidkeyError)
# all went well, therefore:
return True
def generichash_blake2b_init(key=b'',
salt=b'',
person=b'',
digest_size=crypto_generichash_BYTES):
"""
Create a new initialized blake2b hash state
:param key: must be at most
:py:data:`.crypto_generichash_KEYBYTES_MAX` long
:type key: bytes
:param salt: must be at most
:py:data:`.crypto_generichash_SALTBYTES` long;
will be zero-padded if needed
:type salt: bytes
:param person: must be at most
:py:data:`.crypto_generichash_PERSONALBYTES` long:
will be zero-padded if needed
:type person: bytes
:param digest_size: must be at most
:py:data:`.crypto_generichash_BYTES_MAX`;
the default digest size is
:py:data:`.crypto_generichash_BYTES`
:type digest_size: int
:return: an initizialized state buffer
:rtype: bytes
"""
_checkparams(digest_size, key, salt, person)
statebuf = ffi.new("unsigned char[]", crypto_generichash_STATEBYTES)
# both _salt and _personal must be zero-padded to the correct length
_salt = ffi.new("unsigned char []", crypto_generichash_SALTBYTES)
_person = ffi.new("unsigned char []", crypto_generichash_PERSONALBYTES)
ffi.memmove(_salt, salt, len(salt))
ffi.memmove(_person, person, len(person))
rc = lib.crypto_generichash_blake2b_init_salt_personal(
statebuf, key, len(key), digest_size, _salt, _person)
ensure(rc == 0, 'Unexpected failure', raising=exc.RuntimeError)
return statebuf
def sodium_memcmp(inp1, inp2):
"""
Compare contents of two memory regions in constant time
"""
ensure(isinstance(inp1, bytes), raising=exc.TypeError)
ensure(isinstance(inp2, bytes), raising=exc.TypeError)
ln = max(len(inp1), len(inp2))
buf1 = ffi.new("char []", ln)
buf2 = ffi.new("char []", ln)
ffi.memmove(buf1, inp1, len(inp1))
ffi.memmove(buf2, inp2, len(inp2))
eqL = len(inp1) == len(inp2)
eqC = lib.sodium_memcmp(buf1, buf2, ln) == 0
return eqL and eqC
def sodium_memcmp(inp1, inp2):
"""
Compare contents of two memory regions in constant time
"""
ensure(isinstance(inp1, bytes),
raising=exc.TypeError)
ensure(isinstance(inp2, bytes),
raising=exc.TypeError)
ln = max(len(inp1), len(inp2))
buf1 = ffi.new("char []", ln)
buf2 = ffi.new("char []", ln)
ffi.memmove(buf1, inp1, len(inp1))
ffi.memmove(buf2, inp2, len(inp2))
eqL = len(inp1) == len(inp2)
eqC = lib.sodium_memcmp(buf1, buf2, ln) == 0
return eqL and eqC
def crypto_sign_seed_keypair(seed):
"""
Computes and returns the public key and secret key using the seed ``seed``.
:param seed: bytes
:rtype: (bytes(public_key), bytes(secret_key))
"""
if len(seed) != crypto_sign_SEEDBYTES:
raise ValueError("Invalid seed")
pk = ffi.new("unsigned char[]", crypto_sign_PUBLICKEYBYTES)
sk = ffi.new("unsigned char[]", crypto_sign_SECRETKEYBYTES)
rc = lib.crypto_sign_seed_keypair(pk, sk, seed)
ensure(rc == 0,
'Unexpected library error',
raising=exc.RuntimeError)
return (
ffi.buffer(pk, crypto_sign_PUBLICKEYBYTES)[:],
ffi.buffer(sk, crypto_sign_SECRETKEYBYTES)[:],
)
def crypto_secretbox(message, nonce, key):
"""
Encrypts and returns the message ``message`` with the secret ``key`` and
the nonce ``nonce``.
:param message: bytes
:param nonce: bytes
:param key: bytes
:rtype: bytes
"""
if len(key) != crypto_secretbox_KEYBYTES:
raise ValueError("Invalid key")
if len(nonce) != crypto_secretbox_NONCEBYTES:
raise ValueError("Invalid nonce")
padded = b"\x00" * crypto_secretbox_ZEROBYTES + message
ciphertext = ffi.new("unsigned char[]", len(padded))
res = lib.crypto_secretbox(ciphertext, padded, len(padded), nonce, key)
ensure(res == 0, "Encryption failed", raising=exc.CryptoError)
ciphertext = ffi.buffer(ciphertext, len(padded))
return ciphertext[crypto_secretbox_BOXZEROBYTES:]
def crypto_secretbox(message, nonce, key):
"""
Encrypts and returns the message ``message`` with the secret ``key`` and
the nonce ``nonce``.
:param message: bytes
:param nonce: bytes
:param key: bytes
:rtype: bytes
"""
if len(key) != crypto_secretbox_KEYBYTES:
raise ValueError("Invalid key")
if len(nonce) != crypto_secretbox_NONCEBYTES:
raise ValueError("Invalid nonce")
padded = b"\x00" * crypto_secretbox_ZEROBYTES + message
ciphertext = ffi.new("unsigned char[]", len(padded))
res = lib.crypto_secretbox(ciphertext, padded, len(padded), nonce, key)
ensure(res == 0, "Encryption failed", raising=exc.CryptoError)
ciphertext = ffi.buffer(ciphertext, len(padded))
return ciphertext[crypto_secretbox_BOXZEROBYTES:]
def crypto_sign_ed25519_sk_to_curve25519(secret_key_bytes):
"""
Converts a secret Ed25519 key (encoded as bytes ``secret_key_bytes``) to
a secret Curve25519 key as bytes.
Raises a ValueError if ``secret_key_bytes``is not of length
``crypto_sign_SECRETKEYBYTES``
:param public_key_bytes: bytes
:rtype: bytes
"""
if len(secret_key_bytes) != crypto_sign_SECRETKEYBYTES:
raise ValueError("Invalid curve public key")
curve_secret_key_len = crypto_sign_curve25519_BYTES
curve_secret_key = ffi.new("unsigned char[]", curve_secret_key_len)
rc = lib.crypto_sign_ed25519_sk_to_curve25519(curve_secret_key,
secret_key_bytes)
ensure(rc == 0,
'Unexpected library error',
raising=exc.RuntimeError)
return ffi.buffer(curve_secret_key, curve_secret_key_len)[:]
def crypto_box_beforenm(pk, sk):
"""
Computes and returns the shared key for the public key ``pk`` and the
secret key ``sk``. This can be used to speed up operations where the same
set of keys is going to be used multiple times.
:param pk: bytes
:param sk: bytes
:rtype: bytes
"""
if len(pk) != crypto_box_PUBLICKEYBYTES:
raise ValueError("Invalid public key")
if len(sk) != crypto_box_SECRETKEYBYTES:
raise ValueError("Invalid secret key")
k = ffi.new("unsigned char[]", crypto_box_BEFORENMBYTES)
rc = lib.crypto_box_beforenm(k, pk, sk)
ensure(rc == 0,
'Unexpected library error',
raising=exc.RuntimeError)
return ffi.buffer(k, crypto_box_BEFORENMBYTES)[:]
def _sodium_init():
ensure(lib.sodium_init() != -1,
"Could not initialize sodium",
raising=exc.RuntimeError)
def _sodium_init():
ensure(lib.sodium_init() != -1, "Could not initialize sodium", raising=exc.RuntimeError)
def _check_memory_occupation(n, r, p, maxmem=SCRYPT_MAX_MEM):
ensure(r != 0, 'Invalid block size', raising=exc.ValueError)
ensure(p != 0, 'Invalid parallelization factor', raising=exc.ValueError)
ensure((n & (n - 1)) == 0,
'Cost factor must be a power of 2',
raising=exc.ValueError)
ensure(n > 1, 'Cost factor must be at least 2', raising=exc.ValueError)
ensure(p <= SCRYPT_PR_MAX / r,
'p*r is greater than {0}'.format(SCRYPT_PR_MAX),
raising=exc.ValueError)
ensure(n < (1 << (16 * r)), raising=exc.ValueError)
Blen = p * 128 * r
i = UINT64_MAX / 128
ensure(n + 2 <= i / r, raising=exc.ValueError)
Vlen = 32 * r * (n + 2) * 4
ensure(Blen <= UINT64_MAX - Vlen, raising=exc.ValueError)
ensure(Blen <= sys.maxsize - Vlen, raising=exc.ValueError)
ensure(Blen + Vlen <= maxmem,
'Memory limit would be exceeded with the choosen n, r, p',
raising=exc.ValueError)
def crypto_pwhash_scryptsalsa208sha256_ll(passwd,
salt,
n,
r,
p,
dklen=64,
maxmem=SCRYPT_MAX_MEM):
"""
Derive a cryptographic key using the ``passwd`` and ``salt``
given as input.
The work factor can be tuned by by picking different
values for the parameters
:param bytes passwd:
:param bytes salt:
:param bytes salt: *must* be *exactly* :py:const:`.SALTBYTES` long
:param int dklen:
:param int opslimit:
:param int n:
:param int r: block size,
:param int p: the parallelism factor
:param int maxmem: the maximum available memory available for scrypt's
operations
:rtype: bytes
"""
ensure(isinstance(n, int), raising=TypeError)
ensure(isinstance(r, int), raising=TypeError)
ensure(isinstance(p, int), raising=TypeError)
ensure(isinstance(passwd, bytes), raising=TypeError)
ensure(isinstance(salt, bytes), raising=TypeError)
_check_memory_occupation(n, r, p, maxmem)
buf = ffi.new("uint8_t[]", dklen)
ret = lib.crypto_pwhash_scryptsalsa208sha256_ll(passwd, len(passwd), salt,
len(salt), n, r, p, buf,
dklen)
ensure(ret == 0,
'Unexpected failure in key derivation',
raising=exc.RuntimeError)
return ffi.buffer(ffi.cast("char *", buf), dklen)[:]
def _checkparams(digest_size, key, salt, person):
"""Check hash paramters"""
ensure(isinstance(key, bytes),
'Key must be a bytes sequence',
raising=exc.TypeError)
ensure(isinstance(salt, bytes),
'Salt must be a bytes sequence',
raising=exc.TypeError)
ensure(isinstance(person, bytes),
'Person must be a bytes sequence',
raising=exc.TypeError)
ensure(isinstance(digest_size, integer_types),
'Digest size must be an integer number',
raising=exc.TypeError)
ensure(digest_size <= crypto_generichash_BYTES_MAX,
_TOOBIG.format("Digest_size", crypto_generichash_BYTES_MAX),
raising=exc.ValueError)
ensure(len(key) <= crypto_generichash_KEYBYTES_MAX,
_OVERLONG.format("Key", crypto_generichash_KEYBYTES_MAX),
raising=exc.ValueError)
ensure(len(salt) <= crypto_generichash_SALTBYTES,
_OVERLONG.format("Salt", crypto_generichash_SALTBYTES),
raising=exc.ValueError)
ensure(len(person) <= crypto_generichash_PERSONALBYTES,
_OVERLONG.format("Person", crypto_generichash_PERSONALBYTES),
raising=exc.ValueError)