Merge pull request renpy#6742 from bkats/ecsign

Replaces ecdsa python library with OpenSSL (resolves renpy#6686)

Author: renpytom

launcher/game/distribute.rpy

@@ -1719,14 +1719,12 @@ fix_dlc("renios", "renios")
                 f.write(update_data)
 
             # Write the signed file.
-            import ecdsa
-
             with open(self.find_update_pem(), "rb") as f:
-                signing_key = ecdsa.SigningKey.from_pem(f.read())
+                signing_key = renpy.ecsign.pem_to_der(f.read())
 
             fn = renpy.fsencode(os.path.join(self.destination, "updates.ecdsa"))
             with open(fn, "wb") as f:
-                f.write(signing_key.sign(update_data))
+                f.write(renpy.ecsign.sign_data(update_data, signing_key))
 
         def find_update_pem(self):
             if self.build['renpy']:
@@ -1735,14 +1733,12 @@ fix_dlc("renios", "renios")
                 return os.path.join(self.project.path, "update.pem")
 
         def make_key_pem(self):
-            import ecdsa
-
             with open(self.find_update_pem(), "rb") as f:
-                signing_key = ecdsa.SigningKey.from_pem(f.read())
+                signing_key = renpy.ecsign.pem_to_der(f.read())
 
             key_pem = self.temp_filename("key.pem")
             with open(key_pem, "wb") as f:
-                f.write(signing_key.verifying_key.to_pem())
+                f.write(renpy.ecsign.der_to_pem(renpy.ecsign.get_public_key_from_private(signing_key), "PUBLIC"))
 
         def dump(self):
             for k, v in sorted(self.file_lists.items()):

launcher/game/distribute_gui.rpy

@@ -272,8 +272,8 @@ label add_update_pem:
     python hide:
         interface.info("You're trying to build an update, but an update.pem file doesn't exist.\n\nThis file is used to sign updates, and will be automatically created in your projects's base directory.\n\nYou'll need to back up update.pem and keep it safe.", cancel=Jump("build_distributions"))
 
-        import ecdsa
-        key = ecdsa.SigningKey.generate(curve=ecdsa.NIST256p).to_pem()
+        import renpy.ecsign
+        key = renpy.ecsign.der_to_pem(renpy.ecsign.generate_private_key(), "PRIVATE")
 
         with open(os.path.join(project.current.path, "update.pem"), "wb") as f:
             f.write(key)

launcher/game/installer.py

@@ -450,7 +450,7 @@ def manifest(url, renpy=False, insecure=False):
         If true, verificaiton is disabled.
     """
 
-    import ecdsa
+    import renpy.ecsign
 
     download(url, "temp:manifest.py")
 
@@ -463,9 +463,9 @@ def manifest(url, renpy=False, insecure=False):
         with open(_path("temp:manifest.py.sig"), "rb") as f:
             sig = f.read()
 
-        key = ecdsa.VerifyingKey.from_pem(_renpy.exports.open_file("renpy_ecdsa_public.pem").read())
+        key = renpy.ecsign.pem_to_der(_renpy.exports.open_file("renpy_ecdsa_public.pem").read())
 
-        if not key.verify(sig, manifest):
+        if not renpy.ecsign.verify_data(manifest, key, sig):
             error(_("The manifest signature is not valid."))
             return
 

pyproject.toml

@@ -9,7 +9,6 @@ dependencies = [
     "six",
     "pefile",
     "requests",
-    "ecdsa",
     "rsa",
     "setuptools",
     "cython",

renpy/common/00updater.rpy

@@ -817,8 +817,8 @@ init -1500 python in updater:
 
                 try:
 
-                    import ecdsa
-                    verifying_key = ecdsa.VerifyingKey.from_pem(open(key, "rb").read())
+                    import renpy.ecsign
+                    verifying_key = renpy.ecsign.pem_to_der(open(key, "rb").read())
 
                     url = urlparse.urljoin(self.url, "updates.ecdsa")
                     f = urlopen(url)
@@ -828,7 +828,7 @@ init -1500 python in updater:
                         if not signature:
                             break
 
-                        if verifying_key.verify(signature, updates_json):
+                        if renpy.ecsign.verify_data(updates_json, verifying_key, signature):
                             verified = True
 
                     self.log.write("Verified with ECDSA.\n")

renpy/ecsign.pyi

@@ -0,0 +1,78 @@
+# Copyright 2026 B.Kats and Tom Rothamel <pytom@bishoujo.us>
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation files
+# (the "Software"), to deal in the Software without restriction,
+# including without limitation the rights to use, copy, modify, merge,
+# publish, distribute, sublicense, and/or sell copies of the Software,
+# and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+def generate_private_key() -> bytes | None:
+    """
+        Generates a EC private key and return key in DER format
+    """
+
+def sign_data(data : bytes, private_key : bytes) -> bytes:
+    """
+        returns ecdsa signature for data using sha1 hash
+
+        `data`
+            The data to sign
+
+        `private_key`
+            The private key to use in DER format
+    """
+
+def verify_data(data : bytes, public_key : bytes, sign : bytes) -> bool:
+    """
+        verifies ecdsa signature for data using sha1 hash and returns result
+
+        `data`
+            The data to sign
+
+        `public_key`
+            The public key to use in DER format
+
+        `sign`
+            The signature to verify
+    """
+
+def get_public_key_from_private(private_key : bytes) -> bytes | None:
+    """
+        returns public key in DER format from the private key
+
+        `private_key`
+            The private key to use in DER format
+    """
+
+def validate_private_key(private_key : bytes) -> bool:
+    """
+        Validates if given key is a private key
+    """
+
+def validate_public_key(public_key : bytes) -> bool:
+    """
+        Validates if given key is a public key
+    """
+
+def pem_to_der(pem : bytes | str) -> bytes:
+    """
+        unpacks DER from a PEM file
+    """
+
+def der_to_pem(der : bytes, name : str) -> bytes:
+    """
+        packs a DER into a PEM file
+    """

renpy/ecsign.pyx

@@ -0,0 +1,154 @@
+# Copyright 2026 B.Kats and Tom Rothamel <pytom@bishoujo.us>
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation files
+# (the "Software"), to deal in the Software without restriction,
+# including without limitation the rights to use, copy, modify, merge,
+# publish, distribute, sublicense, and/or sell copies of the Software,
+# and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+
+########################################
+## WARNING for when editing this file ##
+########################################
+
+# This file contain functions that need to support async handling for the web build
+# Renaming or reordering any functions will break the async handling
+# The cython generated names for the following functions need to be listed
+# in the ASYNCIFY_ONLY list: (tasks/renpython.py; 2 names for each function)
+# - generate_private_key
+# - sign_data
+# - verify_data
+# - get_public_key_from_private
+# - validate_private_key
+# - validate_public_key
+
+from libc.stdlib cimport free
+import base64
+
+cdef extern from "ec_sign_core.h":
+    int ECSign(const unsigned char *priv_key_der, size_t key_len, const char *data, size_t data_len, char *signature, size_t signature_len);
+    int ECVerify(const unsigned char *public_key_der, size_t key_len, const char *data, size_t data_len, char *signature, size_t signature_len);
+
+    void ECGeneratePrivateKey(unsigned char **priv_key_der, size_t *priv_len);
+    void ECGetPublicKeyFromPrivate(const unsigned char *priv_key_der, size_t priv_len, unsigned char **public_key_der, size_t *pub_len);
+
+    int ECValidateKey(int public, const unsigned char *key_der, size_t key_len);
+
+def generate_private_key() -> bytes | None:
+    cdef unsigned char* privkey = NULL
+    cdef size_t privlen = 0
+
+    ECGeneratePrivateKey(&privkey, &privlen)
+
+    rv = None
+    if privlen > 0 and privkey != NULL:
+        rv = bytes(privkey[:privlen])
+
+    free(privkey);
+
+    return rv
+
+def sign_data(data : bytes, private_key : bytes) -> bytes:
+    sign = bytes(64)
+
+    if not ECSign(private_key, len(private_key), data, len(data), sign, len(sign)):
+        raise Exception("Failed to sign data");
+
+    # print(" ".join("{:02x}".format(x) for x in sign))
+    return sign
+
+def verify_data(data : bytes, public_key : bytes, sign : bytes) -> bool:
+    # print(" ".join("{:02x}".format(x) for x in sign))
+    return ECVerify(public_key, len(public_key), data, len(data), sign, len(sign))
+
+def get_public_key_from_private(private_key : bytes) -> bytes | None:
+    cdef unsigned char* pubkey = NULL
+    cdef size_t publen = 0
+
+    ECGetPublicKeyFromPrivate(private_key, len(private_key), &pubkey, &publen)
+
+    rv = None
+    if publen > 0 and pubkey != NULL:
+        rv = bytes(pubkey[:publen])
+
+    free(pubkey)
+
+    return rv
+
+def validate_private_key(private_key : bytes) -> bool:
+    return ECValidateKey(0, private_key, len(private_key))
+
+def validate_public_key(public_key : bytes) -> bool:
+    return ECValidateKey(1, public_key, len(public_key))
+
+def _pem_lines(contents: bytes) -> typing.Iterator[bytes]:
+    in_pem_part = False
+    seen_pem_start = False
+
+    for line in contents.splitlines():
+        line = line.strip()
+
+        # Skip empty lines
+        if not line:
+            continue
+
+        # Handle start marker
+        if line.startswith(b'-----BEGIN'):
+            if in_pem_part:
+                raise ValueError('Seen start marker twice')
+
+            in_pem_part = True
+            seen_pem_start = True
+            continue
+
+        # Skip stuff before first marker
+        if not in_pem_part:
+            continue
+
+        # Handle end marker
+        if in_pem_part and line.startswith(b'-----END'):
+            in_pem_part = False
+            break
+
+        # Load fields
+        if b":" in line:
+            continue
+
+        yield line
+
+    # Do some sanity checks
+    if not seen_pem_start:
+        raise ValueError('No PEM start marker found')
+
+    if in_pem_part:
+        raise ValueError('No PEM end marker found')
+
+def pem_to_der(pem : bytes | str) -> bytes:
+    if isinstance(pem, str):  # pragma: no branch
+        pem = pem.encode()
+
+    d = b"".join(_pem_lines(pem))
+    return base64.b64decode(d)
+
+
+def der_to_pem(der : bytes, name : str) -> bytes:
+    b64 = base64.b64encode(der)
+    lines = [("-----BEGIN %s KEY-----\n" % name).encode()]
+    lines.extend(
+        [b64[start : start + 76] + b"\n" for start in range(0, len(b64), 76)]
+    )
+    lines.append(("-----END %s KEY-----\n" % name).encode())
+    return b"".join(lines)