Add verify_compact()

export COINCURVE_IGNORE_SYSTEM_LIB=1

coincurve/ecdsa.py

@@ -25,6 +25,17 @@ def der_to_cdata(der, context=GLOBAL_CONTEXT):
     return cdata
 
 
+def parse_compact(data, context=GLOBAL_CONTEXT):
+    cdata = ffi.new('secp256k1_ecdsa_signature *')
+    assert(len(data) == 64)
+    parsed = lib.secp256k1_ecdsa_signature_parse_compact(context.ctx, cdata, data)
+
+    if not parsed:
+        raise ValueError('The DER-encoded signature could not be parsed.')
+
+    return cdata
+
+
 def recover(message, recover_sig, hasher=sha256, context=GLOBAL_CONTEXT):
     msg_hash = hasher(message) if hasher is not None else message
     if len(msg_hash) != 32:

coincurve/keys.py

@@ -1,7 +1,7 @@
 from asn1crypto.keys import ECDomainParameters, ECPointBitString, ECPrivateKey, PrivateKeyAlgorithm, PrivateKeyInfo
 
 from coincurve.context import GLOBAL_CONTEXT
-from coincurve.ecdsa import cdata_to_der, der_to_cdata, deserialize_recoverable, recover, serialize_recoverable
+from coincurve.ecdsa import parse_compact, cdata_to_der, der_to_cdata, deserialize_recoverable, recover, serialize_recoverable
 from coincurve.flags import EC_COMPRESSED, EC_UNCOMPRESSED
 from coincurve.utils import (
     bytes_to_hex,
@@ -249,6 +249,16 @@ class PublicKey:
         # A performance hack to avoid global bool() lookup.
         return not not verified
 
+    def verify_compact(self, signature, message, hasher=sha256):
+        msg_hash = hasher(message) if hasher is not None else message
+        if len(msg_hash) != 32:
+            raise ValueError('Message hash must be 32 bytes long.')
+
+        verified = lib.secp256k1_ecdsa_verify(self.context.ctx, parse_compact(signature), msg_hash, self.public_key)
+
+        # A performance hack to avoid global bool() lookup.
+        return not not verified
+
     def add(self, scalar, update=False):
         scalar = pad_scalar(scalar)
 

setup.py

@@ -139,9 +139,9 @@ class build_clib(_build_clib):
         return build_flags('libsecp256k1', 'l', os.path.abspath(self.build_temp))
 
     def run(self):
-        #if has_system_lib():
-        #    log.info('Using system library')
-        #    return
+        if has_system_lib():
+            log.info('Using system library')
+            return
 
         build_temp = os.path.abspath(self.build_temp)
 
@@ -270,7 +270,7 @@ else:
 
 setup(
     name='coincurve',
-    version='13.0.0',
+    version='13.0.1',
 
     description='Cross-platform Python CFFI bindings for libsecp256k1',
     long_description=open('README.rst', 'r').read(),