Merge pull request #1867 from public/secp256k1-vectors

Script for generating SECP256K1 vectors

4 files changed, 187 insertions, 1 deletions

diff --git a/docs/development/custom-vectors/secp256k1.rst b/docs/development/custom-vectors/secp256k1.rst
new file mode 100644
index 00000000..b19bf4e4
--- /dev/null
+++ b/docs/development/custom-vectors/secp256k1.rst
@@ -0,0 +1,32 @@
+SECP256K1 vector creation
+=========================
+
+This page documents the code that was used to generate the SECP256K1 elliptic
+curve test vectors as well as code used to verify them against another
+implementation.
+
+
+Creation
+--------
+
+The vectors are generated using a `pure Python ecdsa`_ implementation. The test
+messages and combinations of algorithms are derived from the NIST vector data.
+
+.. literalinclude:: /development/custom-vectors/secp256k1/generate_secp256k1.py
+
+Download link: :download:`generate_secp256k1.py
+</development/custom-vectors/secp256k1/generate_secp256k1.py>`
+
+
+Verification
+------------
+
+``cryptography`` was modified to support the SECP256K1 curve. Then
+the following python script was run to generate the vector files.
+
+.. literalinclude:: /development/custom-vectors/secp256k1/verify_secp256k1.py
+
+Download link: :download:`verify_secp256k1.py
+</development/custom-vectors/secp256k1/verify_secp256k1.py>`
+
+.. _`pure Python ecdsa`: https://pypi.python.org/pypi/ecdsa
diff --git a/docs/development/custom-vectors/secp256k1/generate_secp256k1.py b/docs/development/custom-vectors/secp256k1/generate_secp256k1.py
new file mode 100644
index 00000000..502a3ff6
--- /dev/null
+++ b/docs/development/custom-vectors/secp256k1/generate_secp256k1.py
@@ -0,0 +1,89 @@
+from __future__ import absolute_import, print_function
+
+import hashlib
+import os
+from binascii import hexlify
+from collections import defaultdict
+
+from ecdsa import SECP256k1, SigningKey
+from ecdsa.util import sigdecode_der, sigencode_der
+
+from cryptography_vectors import open_vector_file
+
+from tests.utils import (
+    load_fips_ecdsa_signing_vectors, load_vectors_from_file
+)
+
+HASHLIB_HASH_TYPES = {
+    "SHA-1": hashlib.sha1,
+    "SHA-224": hashlib.sha224,
+    "SHA-256": hashlib.sha256,
+    "SHA-384": hashlib.sha384,
+    "SHA-512": hashlib.sha512,
+}
+
+
+class TruncatedHash(object):
+    def __init__(self, hasher):
+        self.hasher = hasher
+
+    def __call__(self, data):
+        self.hasher.update(data)
+        return self
+
+    def digest(self):
+        return self.hasher.digest()[:256 // 8]
+
+
+def build_vectors(fips_vectors):
+    vectors = defaultdict(list)
+    for vector in fips_vectors:
+        vectors[vector['digest_algorithm']].append(vector['message'])
+
+    for digest_algorithm, messages in vectors.items():
+        if digest_algorithm not in HASHLIB_HASH_TYPES:
+            continue
+
+        yield ""
+        yield "[K-256,{0}]".format(digest_algorithm)
+        yield ""
+
+        for message in messages:
+            # Make a hash context
+            hash_func = TruncatedHash(HASHLIB_HASH_TYPES[digest_algorithm]())
+
+            # Sign the message using warner/ecdsa
+            secret_key = SigningKey.generate(curve=SECP256k1)
+            public_key = secret_key.get_verifying_key()
+            signature = secret_key.sign(message, hashfunc=hash_func,
+                                        sigencode=sigencode_der)
+
+            r, s = sigdecode_der(signature, None)
+
+            yield "Msg = {0}".format(hexlify(message))
+            yield "d = {0:x}".format(secret_key.privkey.secret_multiplier)
+            yield "Qx = {0:x}".format(public_key.pubkey.point.x())
+            yield "Qy = {0:x}".format(public_key.pubkey.point.y())
+            yield "R = {0:x}".format(r)
+            yield "S = {0:x}".format(s)
+            yield ""
+
+
+def write_file(lines, dest):
+    for line in lines:
+        print(line)
+        print(line, file=dest)
+
+source_path = os.path.join("asymmetric", "ECDSA", "FIPS_186-3", "SigGen.txt")
+dest_path = os.path.join("asymmetric", "ECDSA", "SECP256K1", "SigGen.txt")
+
+fips_vectors = load_vectors_from_file(
+    source_path,
+    load_fips_ecdsa_signing_vectors
+)
+
+with open_vector_file(dest_path, "w") as dest_file:
+    write_file(
+        build_vectors(fips_vectors),
+        dest_file
+    )
diff --git a/docs/development/custom-vectors/secp256k1/verify_secp256k1.py b/docs/development/custom-vectors/secp256k1/verify_secp256k1.py
new file mode 100644
index 00000000..3d2c25b9
--- /dev/null
+++ b/docs/development/custom-vectors/secp256k1/verify_secp256k1.py
@@ -0,0 +1,59 @@
+from __future__ import absolute_import, print_function
+
+import os
+
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.asymmetric import ec
+from cryptography.hazmat.primitives.asymmetric.utils import (
+    encode_rfc6979_signature
+)
+
+from tests.utils import (
+    load_fips_ecdsa_signing_vectors, load_vectors_from_file
+)
+
+CRYPTOGRAPHY_HASH_TYPES = {
+    "SHA-1": hashes.SHA1,
+    "SHA-224": hashes.SHA224,
+    "SHA-256": hashes.SHA256,
+    "SHA-384": hashes.SHA384,
+    "SHA-512": hashes.SHA512,
+}
+
+
+def verify_one_vector(vector):
+    digest_algorithm = vector['digest_algorithm']
+    message = vector['message']
+    x = vector['x']
+    y = vector['y']
+    signature = encode_rfc6979_signature(vector['r'], vector['s'])
+
+    numbers = ec.EllipticCurvePublicNumbers(
+        x, y,
+        ec.SECP256K1()
+    )
+
+    key = numbers.public_key(default_backend())
+
+    verifier = key.verifier(
+        signature,
+        ec.ECDSA(CRYPTOGRAPHY_HASH_TYPES[digest_algorithm]())
+    )
+    verifier.update(message)
+    return verifier.verify()
+
+
+def verify_vectors(vectors):
+    for vector in vectors:
+        assert verify_one_vector(vector)
+
+
+vector_path = os.path.join("asymmetric", "ECDSA", "SECP256K1", "SigGen.txt")
+
+secp256k1_vectors = load_vectors_from_file(
+    vector_path,
+    load_fips_ecdsa_signing_vectors
+)
+
+verify_vectors(secp256k1_vectors)
diff --git a/docs/development/test-vectors.rst b/docs/development/test-vectors.rst
index f6eecfec..7edf01ab 100644
--- a/docs/development/test-vectors.rst
+++ b/docs/development/test-vectors.rst
@@ -37,9 +37,14 @@ Asymmetric ciphers
   Ruby test suite.
 
 
-Custom Asymmetric Vectors
+Custom asymmetric vectors
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
+.. toctree::
+    :maxdepth: 1
+
+    custom-vectors/secp256k1
+
 * ``asymmetric/PEM_Serialization/ec_private_key.pem`` and
   ``asymmetric/DER_Serialization/ec_private_key.der`` - Contains an Elliptic
   Curve key generated by OpenSSL from the curve ``secp256r1``.
@@ -78,6 +83,7 @@ Custom Asymmetric Vectors
   ``asymmetric/public/PKCS1/rsa.pub.der`` are PKCS1 conversions of the public
   key from ``asymmetric/PKCS8/unenc-rsa-pkcs8.pem`` using PEM and DER encoding.
 
+
 Key exchange
 ~~~~~~~~~~~~