Don't query OpenSSL for block sizes, we already know them
diff --git a/cryptography/hazmat/bindings/openssl/backend.py b/cryptography/hazmat/bindings/openssl/backend.py
index 235a8e3..89ee2b5 100644
--- a/cryptography/hazmat/bindings/openssl/backend.py
+++ b/cryptography/hazmat/bindings/openssl/backend.py
@@ -140,6 +140,7 @@
def __init__(self, backend, cipher, mode, operation):
self._backend = backend
+ self._cipher = cipher
ctx = self._backend.lib.EVP_CIPHER_CTX_new()
ctx = self._backend.ffi.gc(ctx, self._backend.lib.EVP_CIPHER_CTX_free)
@@ -185,9 +186,8 @@
self._ctx = ctx
def update(self, data):
- block_size = self._backend.lib.EVP_CIPHER_CTX_block_size(self._ctx)
buf = self._backend.ffi.new("unsigned char[]",
- len(data) + block_size - 1)
+ len(data) + self._cipher.block_size - 1)
outlen = self._backend.ffi.new("int *")
res = self._backend.lib.EVP_CipherUpdate(self._ctx, buf, outlen, data,
len(data))
@@ -195,8 +195,7 @@
return self._backend.ffi.buffer(buf)[:outlen[0]]
def finalize(self):
- block_size = self._backend.lib.EVP_CIPHER_CTX_block_size(self._ctx)
- buf = self._backend.ffi.new("unsigned char[]", block_size)
+ buf = self._backend.ffi.new("unsigned char[]", self._cipher.block_size)
outlen = self._backend.ffi.new("int *")
res = self._backend.lib.EVP_CipherFinal_ex(self._ctx, buf, outlen)
assert res != 0
diff --git a/cryptography/hazmat/primitives/ciphers/algorithms.py b/cryptography/hazmat/primitives/ciphers/algorithms.py
index cbfaceb..61e93b0 100644
--- a/cryptography/hazmat/primitives/ciphers/algorithms.py
+++ b/cryptography/hazmat/primitives/ciphers/algorithms.py
@@ -120,6 +120,7 @@
class ARC4(object):
name = "RC4"
+ block_size = 1
key_sizes = frozenset([40, 56, 64, 80, 128, 192, 256])
def __init__(self, key):