Update dependency on cryptography (2.x) (#308)

* Update dependency on cryptography

Changes in 2.0.x depend on behavior introduced in cryptography 2.5

* Hardcode python3.8 for static analysis tests in github actions

Python3.9 and pylint do not play nicely

.github/workflows/ci_decrypt-oracle.yaml

@@ -41,7 +41,7 @@ jobs:
         - uses: actions/checkout@v2
         - uses: actions/setup-python@v1
           with:
-            python-version: 3.x
+            python-version: 3.8
         - run: |
             python -m pip install --upgrade pip
             pip install --upgrade -r ci-requirements.txt

.github/workflows/ci_static-analysis.yaml

@@ -30,7 +30,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v1
         with:
-          python-version: 3.x
+          python-version: 3.8
       - run: |
           python -m pip install --upgrade pip
           pip install --upgrade -r ci-requirements.txt

.github/workflows/ci_test-vector-handler.yaml

@@ -76,7 +76,7 @@ jobs:
         - uses: actions/checkout@v2
         - uses: actions/setup-python@v1
           with:
-            python-version: 3.x
+            python-version: 3.8
         - run: |
             python -m pip install --upgrade pip
             pip install --upgrade -r ci-requirements.txt

README.rst

@@ -39,7 +39,7 @@ Required Prerequisites
 ======================
 
 * Python 2.7+ or 3.4+
-* cryptography >= 1.8.1
+* cryptography >= 2.5.0
 * boto3
 * attrs
 

requirements.txt

@@ -1,4 +1,4 @@
 boto3>=1.4.4
-cryptography>=1.8.1
+cryptography>=2.5.0
 attrs>=17.4.0
 wrapt>=1.10.11