Add default field validators

plugins/field_validators/is_json.py

@@ -0,0 +1,26 @@
+import json
+
+# For testing
+try:
+    from django.core.exceptions import ValidationError as UIValidationError
+    from rest_framework.serializers import ValidationError as APIValidationError
+except ImportError:
+    pass
+
+
+def is_json(json_str):
+    try:
+        json.loads(json_str)
+    except ValueError as e:
+        return False
+    return True
+
+
+def validate_api(value):
+    if not is_json(value):
+        raise APIValidationError("is not JSON")
+
+
+def validate_ui(value):
+    if not is_json(value):
+        raise UIValidationError("is not JSON")

plugins/field_validators/is_public_ssh_key.py

@@ -0,0 +1,49 @@
+import base64
+import binascii
+import struct
+
+# For testing
+try:
+    from django.core.exceptions import ValidationError as UIValidationError
+    from rest_framework.serializers import ValidationError as APIValidationError
+except ImportError:
+    pass
+
+ERROR_MESSAGE = "Is not a valid public ssh key"
+
+def is_public_ssh_key(ssh_key):
+    array = ssh_key.split()
+    # Each rsa-ssh key has 3 different strings in it, first one being
+    # type_of_key second one being keystring third one being username.
+    if len(array) not in [2, 3]:
+        return False
+    type_of_key = array[0]
+    ssh_key_str = array[1]
+
+    # must have only valid rsa-ssh key characters ie binascii characters
+    try:
+        data = base64.decodebytes(bytes(ssh_key_str, 'utf-8'))
+    except binascii.Error:
+        return False
+    a = 4
+    # unpack the contents of ssh_key, from ssh_key[:4] , it must be equal to 7 , property of ssh key .
+    try:
+        str_len = struct.unpack('>I', data[:a])[0]
+    except struct.error:
+        return False
+    # ssh_key[4:11] must have string which matches with the type_of_key , another ssh key property.
+    print(str_len)
+    if data[a:a + str_len].decode(encoding='utf-8') == type_of_key:
+        return True
+    else:
+        return False
+
+
+def validate_api(value):
+    if not is_public_ssh_key(value):
+        raise APIValidationError(ERROR_MESSAGE)
+
+
+def validate_ui(value):
+    if not is_public_ssh_key(value):
+        raise UIValidationError(ERROR_MESSAGE)