prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  API: registering an app id and uploading an app release needs to check revoked certificates
  In order to prevent old or lost certificates from being abused we need to check if the certificate has been revoked. This has to be done before validating the certificate on app release upload and before registering a new app id.
  
  
  </issue>
  <code>
  [start of nextcloudappstore/core/certificate/validator.py]
  1 import logging
  2 from base64 import b64decode
  3 
  4 import pem
  5 from OpenSSL.crypto import FILETYPE_PEM, load_certificate, verify, X509, \
  6     X509Store, X509StoreContext, load_crl
  7 from django.conf import settings  # type: ignore
  8 from rest_framework.exceptions import APIException
  9 
  10 logger = logging.getLogger(__name__)
  11 
  12 
  13 class CertificateConfiguration:
  14     def __init__(self) -> None:
  15         self.digest = settings.CERTIFICATE_DIGEST
  16 
  17 
  18 class InvalidSignatureException(APIException):
  19     pass
  20 
  21 
  22 class InvalidCertificateException(APIException):
  23     pass
  24 
  25 
  26 class CertificateAppIdMismatchException(APIException):
  27     pass
  28 
  29 
  30 class CertificateValidator:
  31     """
  32     See https://pyopenssl.readthedocs.io/en/stable/api/crypto.html#signing
  33     -and-verifying-signatures
  34     """
  35 
  36     def __init__(self, config: CertificateConfiguration) -> None:
  37         self.config = config
  38 
  39     def validate_signature(self, certificate: str, signature: str,
  40                            data: bytes) -> None:
  41         """
  42         Tests if a value is a valid certificate using SHA512
  43         :param certificate: the certificate to use as string
  44         :param signature: the signature base64 encoded string to test
  45         :param data: the binary file content that was signed
  46         :raises: InvalidSignatureException if the signature is invalid
  47         :return: None
  48         """
  49         cert = self._to_cert(certificate)
  50         err_msg = 'Signature is invalid'
  51         try:
  52             result = verify(cert, b64decode(signature.encode()), data,
  53                             self.config.digest)
  54             if result is not None:
  55                 raise InvalidSignatureException(err_msg)
  56         except Exception as e:
  57             raise InvalidSignatureException('%s: %s' % (err_msg, str(e)))
  58 
  59     def validate_certificate(self, certificate: str, chain: str,
  60                              crl: str = None) -> None:
  61         """
  62         Tests if a certificate has been signed by the chain, is not revoked
  63         and has not yet been expired.
  64         :param certificate: the certificate to test as string
  65         :param chain: the certificate chain file content as string
  66         :param crl: the certificate revocation list file content as string
  67         :raises: InvalidCertificateException if the certificate is invalid
  68         :return: None
  69         """
  70         # root and intermediary certificate need to be split
  71         cas = pem.parse(chain.encode())
  72         store = X509Store()
  73         for ca in cas:
  74             store.add_cert(self._to_cert(str(ca)))
  75 
  76         cert = self._to_cert(certificate)
  77         ctx = X509StoreContext(store, cert)
  78         err_msg = 'Certificate is invalid'
  79 
  80         if crl:
  81             crl = load_crl(FILETYPE_PEM, crl)
  82             store.add_crl(crl)
  83 
  84         try:
  85             result = ctx.verify_certificate()
  86             if result is not None:
  87                 raise InvalidCertificateException(err_msg)
  88         except Exception as e:
  89             raise InvalidCertificateException('%s: %s' % (err_msg, str(e)))
  90 
  91     def get_cn(self, certificate: str) -> str:
  92         """
  93         Extracts the CN from a certificate and removes the leading
  94         slash, e.g. /news should return news
  95         :param certificate: certificate
  96         :return: the certificate's subject without the leading slash
  97         """
  98         cert = self._to_cert(certificate)
  99         return cert.get_subject().CN
  100 
  101     def validate_app_id(self, certificate: str, app_id: str) -> None:
  102         """
  103         Validates if the CN matches the app id
  104         :param certificate: app certificate
  105         :param app_id: the app id
  106         :raises CertificateAppIdMismatchException: if the app id and cert CN do
  107         not match
  108         :return: None
  109         """
  110         cn = self.get_cn(certificate)
  111         if cn != app_id:
  112             msg = 'App id %s does not match cert CN %s' % (app_id, cn)
  113             raise CertificateAppIdMismatchException(msg)
  114 
  115     def _to_cert(self, certificate: str) -> X509:
  116         return load_certificate(FILETYPE_PEM, certificate.encode())
  117
  [end of nextcloudappstore/core/certificate/validator.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/nextcloudappstore/core/certificate/validator.py b/nextcloudappstore/core/certificate/validator.py
  --- a/nextcloudappstore/core/certificate/validator.py
  +++ b/nextcloudappstore/core/certificate/validator.py
  @@ -3,7 +3,7 @@
   
   import pem
   from OpenSSL.crypto import FILETYPE_PEM, load_certificate, verify, X509, \
  -    X509Store, X509StoreContext, load_crl
  +    X509Store, X509StoreContext, load_crl, X509StoreFlags
   from django.conf import settings  # type: ignore
   from rest_framework.exceptions import APIException
   
  @@ -74,12 +74,14 @@
               store.add_cert(self._to_cert(str(ca)))
   
           cert = self._to_cert(certificate)
  -        ctx = X509StoreContext(store, cert)
  -        err_msg = 'Certificate is invalid'
   
           if crl:
  -            crl = load_crl(FILETYPE_PEM, crl)
  -            store.add_crl(crl)
  +            parsed_crl = load_crl(FILETYPE_PEM, crl)
  +            store.set_flags(X509StoreFlags.CRL_CHECK)
  +            store.add_crl(parsed_crl)
  +
  +        ctx = X509StoreContext(store, cert)
  +        err_msg = 'Certificate is invalid'
   
           try:
               result = ctx.verify_certificate()
  
verification_info: {"golden_diff": "diff --git a/nextcloudappstore/core/certificate/validator.py b/nextcloudappstore/core/certificate/validator.py\n--- a/nextcloudappstore/core/certificate/validator.py\n+++ b/nextcloudappstore/core/certificate/validator.py\n@@ -3,7 +3,7 @@\n \n import pem\n from OpenSSL.crypto import FILETYPE_PEM, load_certificate, verify, X509, \\\n-    X509Store, X509StoreContext, load_crl\n+    X509Store, X509StoreContext, load_crl, X509StoreFlags\n from django.conf import settings  # type: ignore\n from rest_framework.exceptions import APIException\n \n@@ -74,12 +74,14 @@\n             store.add_cert(self._to_cert(str(ca)))\n \n         cert = self._to_cert(certificate)\n-        ctx = X509StoreContext(store, cert)\n-        err_msg = 'Certificate is invalid'\n \n         if crl:\n-            crl = load_crl(FILETYPE_PEM, crl)\n-            store.add_crl(crl)\n+            parsed_crl = load_crl(FILETYPE_PEM, crl)\n+            store.set_flags(X509StoreFlags.CRL_CHECK)\n+            store.add_crl(parsed_crl)\n+\n+        ctx = X509StoreContext(store, cert)\n+        err_msg = 'Certificate is invalid'\n \n         try:\n             result = ctx.verify_certificate()\n", "issue": "API: registering an app id and uploading an app release needs to check revoked certificates\nIn order to prevent old or lost certificates from being abused we need to check if the certificate has been revoked. This has to be done before validating the certificate on app release upload and before registering a new app id.\n\n", "before_files": [{"content": "import logging\nfrom base64 import b64decode\n\nimport pem\nfrom OpenSSL.crypto import FILETYPE_PEM, load_certificate, verify, X509, \\\n    X509Store, X509StoreContext, load_crl\nfrom django.conf import settings  # type: ignore\nfrom rest_framework.exceptions import APIException\n\nlogger = logging.getLogger(__name__)\n\n\nclass CertificateConfiguration:\n    def __init__(self) -> None:\n        self.digest = settings.CERTIFICATE_DIGEST\n\n\nclass InvalidSignatureException(APIException):\n    pass\n\n\nclass InvalidCertificateException(APIException):\n    pass\n\n\nclass CertificateAppIdMismatchException(APIException):\n    pass\n\n\nclass CertificateValidator:\n    \"\"\"\n    See https://pyopenssl.readthedocs.io/en/stable/api/crypto.html#signing\n    -and-verifying-signatures\n    \"\"\"\n\n    def __init__(self, config: CertificateConfiguration) -> None:\n        self.config = config\n\n    def validate_signature(self, certificate: str, signature: str,\n                           data: bytes) -> None:\n        \"\"\"\n        Tests if a value is a valid certificate using SHA512\n        :param certificate: the certificate to use as string\n        :param signature: the signature base64 encoded string to test\n        :param data: the binary file content that was signed\n        :raises: InvalidSignatureException if the signature is invalid\n        :return: None\n        \"\"\"\n        cert = self._to_cert(certificate)\n        err_msg = 'Signature is invalid'\n        try:\n            result = verify(cert, b64decode(signature.encode()), data,\n                            self.config.digest)\n            if result is not None:\n                raise InvalidSignatureException(err_msg)\n        except Exception as e:\n            raise InvalidSignatureException('%s: %s' % (err_msg, str(e)))\n\n    def validate_certificate(self, certificate: str, chain: str,\n                             crl: str = None) -> None:\n        \"\"\"\n        Tests if a certificate has been signed by the chain, is not revoked\n        and has not yet been expired.\n        :param certificate: the certificate to test as string\n        :param chain: the certificate chain file content as string\n        :param crl: the certificate revocation list file content as string\n        :raises: InvalidCertificateException if the certificate is invalid\n        :return: None\n        \"\"\"\n        # root and intermediary certificate need to be split\n        cas = pem.parse(chain.encode())\n        store = X509Store()\n        for ca in cas:\n            store.add_cert(self._to_cert(str(ca)))\n\n        cert = self._to_cert(certificate)\n        ctx = X509StoreContext(store, cert)\n        err_msg = 'Certificate is invalid'\n\n        if crl:\n            crl = load_crl(FILETYPE_PEM, crl)\n            store.add_crl(crl)\n\n        try:\n            result = ctx.verify_certificate()\n            if result is not None:\n                raise InvalidCertificateException(err_msg)\n        except Exception as e:\n            raise InvalidCertificateException('%s: %s' % (err_msg, str(e)))\n\n    def get_cn(self, certificate: str) -> str:\n        \"\"\"\n        Extracts the CN from a certificate and removes the leading\n        slash, e.g. /news should return news\n        :param certificate: certificate\n        :return: the certificate's subject without the leading slash\n        \"\"\"\n        cert = self._to_cert(certificate)\n        return cert.get_subject().CN\n\n    def validate_app_id(self, certificate: str, app_id: str) -> None:\n        \"\"\"\n        Validates if the CN matches the app id\n        :param certificate: app certificate\n        :param app_id: the app id\n        :raises CertificateAppIdMismatchException: if the app id and cert CN do\n        not match\n        :return: None\n        \"\"\"\n        cn = self.get_cn(certificate)\n        if cn != app_id:\n            msg = 'App id %s does not match cert CN %s' % (app_id, cn)\n            raise CertificateAppIdMismatchException(msg)\n\n    def _to_cert(self, certificate: str) -> X509:\n        return load_certificate(FILETYPE_PEM, certificate.encode())\n", "path": "nextcloudappstore/core/certificate/validator.py"}]}