Use pycryptopp for symmetric encryption.

4 files changed, 10 insertions, 12 deletions

diff --git a/changes/feature_use-pycryptopp-for-symmetric-encryption b/changes/feature_use-pycryptopp-for-symmetric-encryption
new file mode 100644
index 00000000..1f28db97
--- /dev/null
+++ b/changes/feature_use-pycryptopp-for-symmetric-encryption
@@ -0,0 +1 @@
+  o Use pycryptopp for symmetric encryption.
diff --git a/soledad/setup.py b/soledad/setup.py
index f2291662..6da976a9 100644
--- a/soledad/setup.py
+++ b/soledad/setup.py
@@ -32,8 +32,7 @@ install_requirements = [
     'six==1.1.0',
     'scrypt',
     'pyxdg',
-    'pycrypto',
-    'pyOpenSSL',
+    'pycryptopp',
 ]
 
 
@@ -43,6 +42,7 @@ tests_requirements = [
     'testscenarios',
     'leap.common',
     'leap.soledad_server',
+    'pyOpenSSL',
 ]
 
 
diff --git a/soledad/src/leap/soledad/crypto.py b/soledad/src/leap/soledad/crypto.py
index bfad66d1..6187b1ab 100644
--- a/soledad/src/leap/soledad/crypto.py
+++ b/soledad/src/leap/soledad/crypto.py
@@ -27,8 +27,7 @@ import hmac
 import hashlib
 
 
-from Crypto.Cipher import AES
-from Crypto.Util import Counter
+from pycryptopp.cipher.aes import AES
 
 
 from leap.soledad import (
@@ -99,10 +98,9 @@ class SoledadCrypto(object):
                 len(key) == 32,  # 32 x 8 = 256 bits.
                 'Wrong key size: %s bits (must be 256 bits long).' %
                 (len(key) * 8))
-            iv = os.urandom(8)
-            ctr = Counter.new(64, prefix=iv)
-            cipher = AES.new(key=key, mode=AES.MODE_CTR, counter=ctr)
-            return binascii.b2a_base64(iv), cipher.encrypt(data)
+            iv = os.urandom(16)
+            ciphertext = AES(key=key, iv=iv).process(data)
+            return binascii.b2a_base64(iv), ciphertext
 
         # raise if method is unknown
         raise UnknownEncryptionMethod('Unkwnown method: %s' % method)
@@ -137,9 +135,8 @@ class SoledadCrypto(object):
             soledad_assert(
                 'iv' in kwargs,
                 'AES-256-CTR needs an initial value.')
-            ctr = Counter.new(64, prefix=binascii.a2b_base64(kwargs['iv']))
-            cipher = AES.new(key=key, mode=AES.MODE_CTR, counter=ctr)
-            return cipher.decrypt(data)
+            return AES(
+                key=key, iv=binascii.a2b_base64(kwargs['iv'])).process(data)
 
         # raise if method is unknown
         raise UnknownEncryptionMethod('Unkwnown method: %s' % method)
diff --git a/soledad/src/leap/soledad/target.py b/soledad/src/leap/soledad/target.py
index 9fac9f54..cad51b74 100644
--- a/soledad/src/leap/soledad/target.py
+++ b/soledad/src/leap/soledad/target.py
@@ -168,7 +168,7 @@ def encrypt_doc(crypto, doc):
     soledad_assert(doc.is_tombstone() is False)
     # encrypt content using AES-256 CTR mode
     iv, ciphertext = crypto.encrypt_sym(
-        doc.get_json(),
+        str(doc.get_json()),  # encryption/decryption routines expect str
         crypto.doc_passphrase(doc.doc_id),
         method=EncryptionMethods.AES_256_CTR)
     # Return a representation for the encrypted content. In the following, we