Squashed 'lib/curve25519-donna/' content from commit 28772f3

git-subtree-dir: lib/curve25519-donna
git-subtree-split: 28772f37a4b8a57ab9439b9e79b19f9abee686da

6 files changed, 300 insertions, 0 deletions

diff --git a/python-src/curve25519/__init__.py b/python-src/curve25519/__init__.py
new file mode 100644
index 0000000..873ff57
--- /dev/null
+++ b/python-src/curve25519/__init__.py
@@ -0,0 +1,4 @@
+
+from .keys import Private, Public
+
+hush_pyflakes = [Private, Public]; del hush_pyflakes
diff --git a/python-src/curve25519/curve25519module.c b/python-src/curve25519/curve25519module.c
new file mode 100644
index 0000000..e309ec0
--- /dev/null
+++ b/python-src/curve25519/curve25519module.c
@@ -0,0 +1,105 @@
+/* tell python that PyArg_ParseTuple(t#) means Py_ssize_t, not int */
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+#if (PY_VERSION_HEX < 0x02050000)
+	typedef int Py_ssize_t;
+#endif
+
+/* This is required for compatibility with Python 2. */
+#if PY_MAJOR_VERSION >= 3
+	#include <bytesobject.h> 
+	#define y "y"
+#else
+	#define PyBytes_FromStringAndSize PyString_FromStringAndSize
+	#define y "t"
+#endif
+
+int curve25519_donna(char *mypublic, 
+                     const char *secret, const char *basepoint);
+
+static PyObject *
+pycurve25519_makeprivate(PyObject *self, PyObject *args)
+{
+    char *in1;
+    Py_ssize_t in1len;
+    if (!PyArg_ParseTuple(args, y"#:clamp", &in1, &in1len))
+        return NULL;
+    if (in1len != 32) {
+        PyErr_SetString(PyExc_ValueError, "input must be 32-byte string");
+        return NULL;
+    }
+    in1[0] &= 248;
+    in1[31] &= 127;
+    in1[31] |= 64;
+    return PyBytes_FromStringAndSize((char *)in1, 32);
+}
+
+static PyObject *
+pycurve25519_makepublic(PyObject *self, PyObject *args)
+{
+    const char *private;
+    char mypublic[32];
+    char basepoint[32] = {9};
+    Py_ssize_t privatelen;
+    if (!PyArg_ParseTuple(args, y"#:makepublic", &private, &privatelen))
+        return NULL;
+    if (privatelen != 32) {
+        PyErr_SetString(PyExc_ValueError, "input must be 32-byte string");
+        return NULL;
+    }
+    curve25519_donna(mypublic, private, basepoint);
+    return PyBytes_FromStringAndSize((char *)mypublic, 32);
+}
+
+static PyObject *
+pycurve25519_makeshared(PyObject *self, PyObject *args)
+{
+    const char *myprivate, *theirpublic;
+    char shared_key[32];
+    Py_ssize_t myprivatelen, theirpubliclen;
+    if (!PyArg_ParseTuple(args, y"#"y"#:generate",
+                          &myprivate, &myprivatelen, &theirpublic, &theirpubliclen))
+        return NULL;
+    if (myprivatelen != 32) {
+        PyErr_SetString(PyExc_ValueError, "input must be 32-byte string");
+        return NULL;
+    }
+    if (theirpubliclen != 32) {
+        PyErr_SetString(PyExc_ValueError, "input must be 32-byte string");
+        return NULL;
+    }
+    curve25519_donna(shared_key, myprivate, theirpublic);
+    return PyBytes_FromStringAndSize((char *)shared_key, 32);
+}
+
+
+static PyMethodDef
+curve25519_functions[] = {
+    {"make_private", pycurve25519_makeprivate, METH_VARARGS, "data->private"},
+    {"make_public", pycurve25519_makepublic, METH_VARARGS, "private->public"},
+    {"make_shared", pycurve25519_makeshared, METH_VARARGS, "private+public->shared"},
+    {NULL, NULL, 0, NULL},
+};
+
+#if PY_MAJOR_VERSION >= 3
+    static struct PyModuleDef
+    curve25519_module = {
+        PyModuleDef_HEAD_INIT,
+        "_curve25519",
+        NULL,
+        NULL,
+        curve25519_functions,
+    };
+
+    PyObject *
+    PyInit__curve25519(void)
+    {
+        return PyModule_Create(&curve25519_module);
+    }
+#else
+    PyMODINIT_FUNC
+    init_curve25519(void)
+    {
+          (void)Py_InitModule("_curve25519", curve25519_functions);
+    }
+#endif
\ No newline at end of file
diff --git a/python-src/curve25519/keys.py b/python-src/curve25519/keys.py
new file mode 100644
index 0000000..e131dac
--- /dev/null
+++ b/python-src/curve25519/keys.py
@@ -0,0 +1,46 @@
+from . import _curve25519
+from hashlib import sha256
+import os
+
+# the curve25519 functions are really simple, and could be used without an
+# OOP layer, but it's a bit too easy to accidentally swap the private and
+# public keys that way.
+
+def _hash_shared(shared):
+    return sha256(b"curve25519-shared:"+shared).digest()
+
+class Private:
+    def __init__(self, secret=None, seed=None):
+        if secret is None:
+            if seed is None:
+                secret = os.urandom(32)
+            else:
+                secret = sha256(b"curve25519-private:"+seed).digest()
+        else:
+            assert seed is None, "provide secret, seed, or neither, not both"
+        if not isinstance(secret, bytes) or len(secret) != 32:
+            raise TypeError("secret= must be 32-byte string")
+        self.private = _curve25519.make_private(secret)
+
+    def serialize(self):
+        return self.private
+
+    def get_public(self):
+        return Public(_curve25519.make_public(self.private))
+
+    def get_shared_key(self, public, hashfunc=None):
+        if not isinstance(public, Public):
+            raise ValueError("'public' must be an instance of Public")
+        if hashfunc is None:
+            hashfunc = _hash_shared
+        shared = _curve25519.make_shared(self.private, public.public)
+        return hashfunc(shared)
+
+class Public:
+    def __init__(self, public):
+        assert isinstance(public, bytes)
+        assert len(public) == 32
+        self.public = public
+
+    def serialize(self):
+        return self.public
diff --git a/python-src/curve25519/test/__init__.py b/python-src/curve25519/test/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/python-src/curve25519/test/__init__.py
diff --git a/python-src/curve25519/test/test_curve25519.py b/python-src/curve25519/test/test_curve25519.py
new file mode 100755
index 0000000..2ecbd47
--- /dev/null
+++ b/python-src/curve25519/test/test_curve25519.py
@@ -0,0 +1,99 @@
+#! /usr/bin/python
+
+import unittest
+
+from curve25519 import Private, Public
+from hashlib import sha1, sha256
+from binascii import hexlify
+
+class Basic(unittest.TestCase):
+    def test_basic(self):
+        secret1 = b"abcdefghijklmnopqrstuvwxyz123456"
+        self.assertEqual(len(secret1), 32)
+
+        secret2 = b"654321zyxwvutsrqponmlkjihgfedcba"
+        self.assertEqual(len(secret2), 32)
+        priv1 = Private(secret=secret1)
+        pub1 = priv1.get_public()
+        priv2 = Private(secret=secret2)
+        pub2 = priv2.get_public()
+        shared12 = priv1.get_shared_key(pub2)
+        e = b"b0818125eab42a8ac1af5e8b9b9c15ed2605c2bbe9675de89e5e6e7f442b9598"
+        self.assertEqual(hexlify(shared12), e)
+        shared21 = priv2.get_shared_key(pub1)
+        self.assertEqual(shared12, shared21)
+
+        pub2a = Public(pub2.serialize())
+        shared12a = priv1.get_shared_key(pub2a)
+        self.assertEqual(hexlify(shared12a), e)
+
+    def test_errors(self):
+        priv1 = Private()
+        self.assertRaises(ValueError, priv1.get_shared_key, priv1)
+
+    def test_seed(self):
+        # use 32-byte secret
+        self.assertRaises(TypeError, Private, secret=123)
+        self.assertRaises(TypeError, Private, secret=b"too short")
+        secret1 = b"abcdefghijklmnopqrstuvwxyz123456"
+        assert len(secret1) == 32
+        priv1 = Private(secret=secret1)
+        priv1a = Private(secret=secret1)
+        priv1b = Private(priv1.serialize())
+        self.assertEqual(priv1.serialize(), priv1a.serialize())
+        self.assertEqual(priv1.serialize(), priv1b.serialize())
+        e = b"6062636465666768696a6b6c6d6e6f707172737475767778797a313233343576"
+        self.assertEqual(hexlify(priv1.serialize()), e)
+
+        # the private key is a clamped form of the secret, so they won't
+        # quite be the same
+        p = Private(secret=b"\x00"*32)
+        self.assertEqual(hexlify(p.serialize()), b"00"*31+b"40")
+        p = Private(secret=b"\xff"*32)
+        self.assertEqual(hexlify(p.serialize()), b"f8"+b"ff"*30+b"7f")
+
+        # use arbitrary-length seed
+        self.assertRaises(TypeError, Private, seed=123)
+        priv1 = Private(seed=b"abc")
+        priv1a = Private(seed=b"abc")
+        priv1b = Private(priv1.serialize())
+        self.assertEqual(priv1.serialize(), priv1a.serialize())
+        self.assertEqual(priv1.serialize(), priv1b.serialize())
+        self.assertRaises(AssertionError, Private, seed=b"abc", secret=b"no")
+
+        priv1 = Private(seed=b"abc")
+        priv1a = Private(priv1.serialize())
+        self.assertEqual(priv1.serialize(), priv1a.serialize())
+        self.assertRaises(AssertionError, Private, seed=b"abc", secret=b"no")
+
+        # use built-in os.urandom
+        priv2 = Private()
+        priv2a = Private(priv2.private)
+        self.assertEqual(priv2.serialize(), priv2a.serialize())
+
+        # attempt to use both secret= and seed=, not allowed
+        self.assertRaises(AssertionError, Private, seed=b"abc", secret=b"no")
+
+    def test_hashfunc(self):
+        priv1 = Private(seed=b"abc")
+        priv2 = Private(seed=b"def")
+        shared_sha256 = priv1.get_shared_key(priv2.get_public())
+        e = b"da959ffe77ebeb4757fe5ba310e28ede425ae0d0ff5ec9c884e2d08f311cf5e5"
+        self.assertEqual(hexlify(shared_sha256), e)
+
+        # confirm the hash function remains what we think it is
+        def myhash(shared_key):
+            return sha256(b"curve25519-shared:"+shared_key).digest()
+        shared_myhash = priv1.get_shared_key(priv2.get_public(), myhash)
+        self.assertEqual(hexlify(shared_myhash), e)
+
+        def hexhash(shared_key):
+            return sha1(shared_key).hexdigest().encode()
+        shared_hexhash = priv1.get_shared_key(priv2.get_public(), hexhash)
+        self.assertEqual(shared_hexhash,
+                             b"80eec98222c8edc4324fb9477a3c775ce7c6c93a")
+
+
+if __name__ == "__main__":
+    unittest.main()
+
diff --git a/python-src/curve25519/test/test_speed.py b/python-src/curve25519/test/test_speed.py
new file mode 100755
index 0000000..87952fa
--- /dev/null
+++ b/python-src/curve25519/test/test_speed.py
@@ -0,0 +1,46 @@
+#! /usr/bin/python
+
+from time import time
+from curve25519 import Private
+
+count = 10000
+elapsed_get_public = 0.0
+elapsed_get_shared = 0.0
+
+def abbreviate_time(data):
+    # 1.23s, 790ms, 132us
+    if data is None:
+        return ""
+    s = float(data)
+    if s >= 10:
+        #return abbreviate.abbreviate_time(data)
+        return "%d" % s
+    if s >= 1.0:
+        return "%.2fs" % s
+    if s >= 0.01:
+        return "%dms" % (1000*s)
+    if s >= 0.001:
+        return "%.1fms" % (1000*s)
+    if s >= 0.000001:
+        return "%.1fus" % (1000000*s)
+    return "%dns" % (1000000000*s)
+
+def nohash(key): return key
+
+for i in range(count):
+    p = Private()
+    start = time()
+    pub = p.get_public()
+    elapsed_get_public += time() - start
+    pub2 = Private().get_public()
+    start = time()
+    shared = p.get_shared_key(pub2) #, hashfunc=nohash)
+    elapsed_get_shared += time() - start
+
+print("get_public: %s" % abbreviate_time(elapsed_get_public / count))
+print("get_shared: %s" % abbreviate_time(elapsed_get_shared / count))
+
+# these take about 560us-570us each (with the default compiler settings, -Os)
+# on my laptop, same with -O2
+#  of which the python overhead is about 5us
+#  and the get_shared_key() hash step adds about 5us