3 files changed, 69 insertions, 0 deletions
diff --git a/python/olm/__init__.py b/python/olm/__init__.py
index 31b29b9..f74cbcb 100644
--- a/python/olm/__init__.py
+++ b/python/olm/__init__.py
@@ -2,3 +2,4 @@ from .account import Account
 from .session import Session
 from .outbound_group_session import OutboundGroupSession
 from .inbound_group_session import InboundGroupSession
+from .utility import ed25519_verify
diff --git a/python/olm/__main__.py b/python/olm/__main__.py
index 71f018a..2a48b78 100755
--- a/python/olm/__main__.py
+++ b/python/olm/__main__.py
@@ -344,6 +344,9 @@ def build_arg_parser():
     )
     export_inbound_group.set_defaults(func=do_export_inbound_group)
 
+    ed25519_verify = commands.add_parser("ed25519_verify",
+                                         help="Verify an ed25519 signature")
+    ed25519_verify.set_defaults(func=do_verify_ed25519_signature)
     return parser
 
 
@@ -430,6 +433,15 @@ def do_export_inbound_group(args):
     args.export_file.write(session.export_session(index))
 
 
+def do_verify_ed25519_signature(args):
+    account = Account()
+    account.create()
+    message = "A Message".encode("ASCII")
+    ed25519_key = account.identity_keys()["ed25519"].encode("utf-8")
+    signature = account.sign(message)
+    ed25519_verify(ed25519_key, message, signature)
+
+
 if __name__ == '__main__':
     parser = build_arg_parser()
     args = parser.parse_args()
diff --git a/python/olm/utility.py b/python/olm/utility.py
new file mode 100644
index 0000000..dac0225
--- /dev/null
+++ b/python/olm/utility.py
@@ -0,0 +1,56 @@
+from ._base import lib, c_void_p, c_size_t, c_char_p, \
+    create_string_buffer, ERR, OlmError
+
+lib.olm_utility_size.argtypes = []
+lib.olm_utility_size.restype = c_size_t
+
+lib.olm_utility.argtypes = [c_void_p]
+lib.olm_utility.restype = c_void_p
+
+lib.olm_utility_last_error.argtypes = [c_void_p]
+lib.olm_utility_last_error.restype = c_char_p
+
+
+def utility_errcheck(res, func, args):
+    if res == ERR:
+        raise OlmError("%s: %s" % (
+            func.__name__, lib.olm_utility_last_error(args[0])
+        ))
+    return res
+
+
+def utility_function(func, *types):
+    func.argtypes = (c_void_p,) + types
+    func.restypes = c_size_t
+    func.errcheck = utility_errcheck
+
+utility_function(
+    lib.olm_ed25519_verify,
+    c_void_p, c_size_t,  # key, key_length
+    c_void_p, c_size_t,  # message, message_length
+    c_void_p, c_size_t,  # signature, signature_length
+)
+
+
+class Utility(object):
+    def __init__(self):
+        self.buf = create_string_buffer(lib.olm_utility_size())
+        self.ptr = lib.olm_utility(self.buf)
+
+_utility = None
+
+
+def ed25519_verify(key, message, signature):
+    """ Verify an ed25519 signature. Raises an OlmError if verification fails.
+    Args:
+        key(bytes): The ed25519 public key used for signing.
+        message(bytes): The signed message.
+        signature(bytes): The message signature.
+    """
+    global _utility
+    if not _utility:
+        _utility = Utility()
+    lib.olm_ed25519_verify(_utility.ptr,
+                           key, len(key),
+                           message, len(message),
+                           signature, len(signature))