two version of R2R are hereHEADmaster

1 files changed, 991 insertions, 0 deletions

diff --git a/.venv/lib/python3.12/site-packages/botocore/signers.py b/.venv/lib/python3.12/site-packages/botocore/signers.py
new file mode 100644
index 00000000..cf90fe4a
--- /dev/null
+++ b/.venv/lib/python3.12/site-packages/botocore/signers.py
@@ -0,0 +1,991 @@
+# Copyright 2014 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+# http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+import base64
+import datetime
+import json
+import weakref
+
+import botocore
+import botocore.auth
+from botocore.awsrequest import create_request_object, prepare_request_dict
+from botocore.compat import OrderedDict
+from botocore.exceptions import (
+    ParamValidationError,
+    UnknownClientMethodError,
+    UnknownSignatureVersionError,
+    UnsupportedSignatureVersionError,
+)
+from botocore.utils import ArnParser, datetime2timestamp
+
+# Keep these imported.  There's pre-existing code that uses them.
+from botocore.utils import fix_s3_host  # noqa
+
+
+class RequestSigner:
+    """
+    An object to sign requests before they go out over the wire using
+    one of the authentication mechanisms defined in ``auth.py``. This
+    class fires two events scoped to a service and operation name:
+
+    * choose-signer: Allows overriding the auth signer name.
+    * before-sign: Allows mutating the request before signing.
+
+    Together these events allow for customization of the request
+    signing pipeline, including overrides, request path manipulation,
+    and disabling signing per operation.
+
+
+    :type service_id: botocore.model.ServiceId
+    :param service_id: The service id for the service, e.g. ``S3``
+
+    :type region_name: string
+    :param region_name: Name of the service region, e.g. ``us-east-1``
+
+    :type signing_name: string
+    :param signing_name: Service signing name. This is usually the
+                         same as the service name, but can differ. E.g.
+                         ``emr`` vs. ``elasticmapreduce``.
+
+    :type signature_version: string
+    :param signature_version: Signature name like ``v4``.
+
+    :type credentials: :py:class:`~botocore.credentials.Credentials`
+    :param credentials: User credentials with which to sign requests.
+
+    :type event_emitter: :py:class:`~botocore.hooks.BaseEventHooks`
+    :param event_emitter: Extension mechanism to fire events.
+    """
+
+    def __init__(
+        self,
+        service_id,
+        region_name,
+        signing_name,
+        signature_version,
+        credentials,
+        event_emitter,
+        auth_token=None,
+    ):
+        self._region_name = region_name
+        self._signing_name = signing_name
+        self._signature_version = signature_version
+        self._credentials = credentials
+        self._auth_token = auth_token
+        self._service_id = service_id
+
+        # We need weakref to prevent leaking memory in Python 2.6 on Linux 2.6
+        self._event_emitter = weakref.proxy(event_emitter)
+
+    @property
+    def region_name(self):
+        return self._region_name
+
+    @property
+    def signature_version(self):
+        return self._signature_version
+
+    @property
+    def signing_name(self):
+        return self._signing_name
+
+    def handler(self, operation_name=None, request=None, **kwargs):
+        # This is typically hooked up to the "request-created" event
+        # from a client's event emitter.  When a new request is created
+        # this method is invoked to sign the request.
+        # Don't call this method directly.
+        return self.sign(operation_name, request)
+
+    def sign(
+        self,
+        operation_name,
+        request,
+        region_name=None,
+        signing_type='standard',
+        expires_in=None,
+        signing_name=None,
+    ):
+        """Sign a request before it goes out over the wire.
+
+        :type operation_name: string
+        :param operation_name: The name of the current operation, e.g.
+                               ``ListBuckets``.
+        :type request: AWSRequest
+        :param request: The request object to be sent over the wire.
+
+        :type region_name: str
+        :param region_name: The region to sign the request for.
+
+        :type signing_type: str
+        :param signing_type: The type of signing to perform. This can be one of
+            three possible values:
+
+            * 'standard'     - This should be used for most requests.
+            * 'presign-url'  - This should be used when pre-signing a request.
+            * 'presign-post' - This should be used when pre-signing an S3 post.
+
+        :type expires_in: int
+        :param expires_in: The number of seconds the presigned url is valid
+            for. This parameter is only valid for signing type 'presign-url'.
+
+        :type signing_name: str
+        :param signing_name: The name to use for the service when signing.
+        """
+        explicit_region_name = region_name
+        if region_name is None:
+            region_name = self._region_name
+
+        if signing_name is None:
+            signing_name = self._signing_name
+
+        signature_version = self._choose_signer(
+            operation_name, signing_type, request.context
+        )
+
+        # Allow mutating request before signing
+        self._event_emitter.emit(
+            f'before-sign.{self._service_id.hyphenize()}.{operation_name}',
+            request=request,
+            signing_name=signing_name,
+            region_name=self._region_name,
+            signature_version=signature_version,
+            request_signer=self,
+            operation_name=operation_name,
+        )
+
+        if signature_version != botocore.UNSIGNED:
+            kwargs = {
+                'signing_name': signing_name,
+                'region_name': region_name,
+                'signature_version': signature_version,
+            }
+            if expires_in is not None:
+                kwargs['expires'] = expires_in
+            signing_context = request.context.get('signing', {})
+            if not explicit_region_name and signing_context.get('region'):
+                kwargs['region_name'] = signing_context['region']
+            if signing_context.get('signing_name'):
+                kwargs['signing_name'] = signing_context['signing_name']
+            if signing_context.get('request_credentials'):
+                kwargs['request_credentials'] = signing_context[
+                    'request_credentials'
+                ]
+            if signing_context.get('identity_cache') is not None:
+                self._resolve_identity_cache(
+                    kwargs,
+                    signing_context['identity_cache'],
+                    signing_context['cache_key'],
+                )
+            try:
+                auth = self.get_auth_instance(**kwargs)
+            except UnknownSignatureVersionError as e:
+                if signing_type != 'standard':
+                    raise UnsupportedSignatureVersionError(
+                        signature_version=signature_version
+                    )
+                else:
+                    raise e
+
+            auth.add_auth(request)
+
+    def _resolve_identity_cache(self, kwargs, cache, cache_key):
+        kwargs['identity_cache'] = cache
+        kwargs['cache_key'] = cache_key
+
+    def _choose_signer(self, operation_name, signing_type, context):
+        """
+        Allow setting the signature version via the choose-signer event.
+        A value of `botocore.UNSIGNED` means no signing will be performed.
+
+        :param operation_name: The operation to sign.
+        :param signing_type: The type of signing that the signer is to be used
+            for.
+        :return: The signature version to sign with.
+        """
+        signing_type_suffix_map = {
+            'presign-post': '-presign-post',
+            'presign-url': '-query',
+        }
+        suffix = signing_type_suffix_map.get(signing_type, '')
+
+        # operation specific signing context takes precedent over client-level
+        # defaults
+        signature_version = context.get('auth_type') or self._signature_version
+        signing = context.get('signing', {})
+        signing_name = signing.get('signing_name', self._signing_name)
+        region_name = signing.get('region', self._region_name)
+        if (
+            signature_version is not botocore.UNSIGNED
+            and not signature_version.endswith(suffix)
+        ):
+            signature_version += suffix
+
+        handler, response = self._event_emitter.emit_until_response(
+            f'choose-signer.{self._service_id.hyphenize()}.{operation_name}',
+            signing_name=signing_name,
+            region_name=region_name,
+            signature_version=signature_version,
+            context=context,
+        )
+
+        if response is not None:
+            signature_version = response
+            # The suffix needs to be checked again in case we get an improper
+            # signature version from choose-signer.
+            if (
+                signature_version is not botocore.UNSIGNED
+                and not signature_version.endswith(suffix)
+            ):
+                signature_version += suffix
+
+        return signature_version
+
+    def get_auth_instance(
+        self,
+        signing_name,
+        region_name,
+        signature_version=None,
+        request_credentials=None,
+        **kwargs,
+    ):
+        """
+        Get an auth instance which can be used to sign a request
+        using the given signature version.
+
+        :type signing_name: string
+        :param signing_name: Service signing name. This is usually the
+                             same as the service name, but can differ. E.g.
+                             ``emr`` vs. ``elasticmapreduce``.
+
+        :type region_name: string
+        :param region_name: Name of the service region, e.g. ``us-east-1``
+
+        :type signature_version: string
+        :param signature_version: Signature name like ``v4``.
+
+        :rtype: :py:class:`~botocore.auth.BaseSigner`
+        :return: Auth instance to sign a request.
+        """
+        if signature_version is None:
+            signature_version = self._signature_version
+
+        cls = botocore.auth.AUTH_TYPE_MAPS.get(signature_version)
+        if cls is None:
+            raise UnknownSignatureVersionError(
+                signature_version=signature_version
+            )
+
+        if cls.REQUIRES_TOKEN is True:
+            frozen_token = None
+            if self._auth_token is not None:
+                frozen_token = self._auth_token.get_frozen_token()
+            auth = cls(frozen_token)
+            return auth
+
+        credentials = request_credentials or self._credentials
+        if getattr(cls, "REQUIRES_IDENTITY_CACHE", None) is True:
+            cache = kwargs["identity_cache"]
+            key = kwargs["cache_key"]
+            credentials = cache.get_credentials(key)
+            del kwargs["cache_key"]
+
+        # If there's no credentials provided (i.e credentials is None),
+        # then we'll pass a value of "None" over to the auth classes,
+        # which already handle the cases where no credentials have
+        # been provided.
+        frozen_credentials = None
+        if credentials is not None:
+            frozen_credentials = credentials.get_frozen_credentials()
+        kwargs['credentials'] = frozen_credentials
+        if cls.REQUIRES_REGION:
+            if self._region_name is None:
+                raise botocore.exceptions.NoRegionError()
+            kwargs['region_name'] = region_name
+            kwargs['service_name'] = signing_name
+        auth = cls(**kwargs)
+        return auth
+
+    # Alias get_auth for backwards compatibility.
+    get_auth = get_auth_instance
+
+    def generate_presigned_url(
+        self,
+        request_dict,
+        operation_name,
+        expires_in=3600,
+        region_name=None,
+        signing_name=None,
+    ):
+        """Generates a presigned url
+
+        :type request_dict: dict
+        :param request_dict: The prepared request dictionary returned by
+            ``botocore.awsrequest.prepare_request_dict()``
+
+        :type operation_name: str
+        :param operation_name: The operation being signed.
+
+        :type expires_in: int
+        :param expires_in: The number of seconds the presigned url is valid
+            for. By default it expires in an hour (3600 seconds)
+
+        :type region_name: string
+        :param region_name: The region name to sign the presigned url.
+
+        :type signing_name: str
+        :param signing_name: The name to use for the service when signing.
+
+        :returns: The presigned url
+        """
+        request = create_request_object(request_dict)
+        self.sign(
+            operation_name,
+            request,
+            region_name,
+            'presign-url',
+            expires_in,
+            signing_name,
+        )
+
+        request.prepare()
+        return request.url
+
+
+class CloudFrontSigner:
+    '''A signer to create a signed CloudFront URL.
+
+    First you create a cloudfront signer based on a normalized RSA signer::
+
+        import rsa
+        def rsa_signer(message):
+            private_key = open('private_key.pem', 'r').read()
+            return rsa.sign(
+                message,
+                rsa.PrivateKey.load_pkcs1(private_key.encode('utf8')),
+                'SHA-1')  # CloudFront requires SHA-1 hash
+        cf_signer = CloudFrontSigner(key_id, rsa_signer)
+
+    To sign with a canned policy::
+
+        signed_url = cf_signer.generate_signed_url(
+            url, date_less_than=datetime(2015, 12, 1))
+
+    To sign with a custom policy::
+
+        signed_url = cf_signer.generate_signed_url(url, policy=my_policy)
+    '''
+
+    def __init__(self, key_id, rsa_signer):
+        """Create a CloudFrontSigner.
+
+        :type key_id: str
+        :param key_id: The CloudFront Key Pair ID
+
+        :type rsa_signer: callable
+        :param rsa_signer: An RSA signer.
+               Its only input parameter will be the message to be signed,
+               and its output will be the signed content as a binary string.
+               The hash algorithm needed by CloudFront is SHA-1.
+        """
+        self.key_id = key_id
+        self.rsa_signer = rsa_signer
+
+    def generate_presigned_url(self, url, date_less_than=None, policy=None):
+        """Creates a signed CloudFront URL based on given parameters.
+
+        :type url: str
+        :param url: The URL of the protected object
+
+        :type date_less_than: datetime
+        :param date_less_than: The URL will expire after that date and time
+
+        :type policy: str
+        :param policy: The custom policy, possibly built by self.build_policy()
+
+        :rtype: str
+        :return: The signed URL.
+        """
+        both_args_supplied = date_less_than is not None and policy is not None
+        neither_arg_supplied = date_less_than is None and policy is None
+        if both_args_supplied or neither_arg_supplied:
+            e = 'Need to provide either date_less_than or policy, but not both'
+            raise ValueError(e)
+        if date_less_than is not None:
+            # We still need to build a canned policy for signing purpose
+            policy = self.build_policy(url, date_less_than)
+        if isinstance(policy, str):
+            policy = policy.encode('utf8')
+        if date_less_than is not None:
+            params = [f'Expires={int(datetime2timestamp(date_less_than))}']
+        else:
+            params = [f"Policy={self._url_b64encode(policy).decode('utf8')}"]
+        signature = self.rsa_signer(policy)
+        params.extend(
+            [
+                f"Signature={self._url_b64encode(signature).decode('utf8')}",
+                f"Key-Pair-Id={self.key_id}",
+            ]
+        )
+        return self._build_url(url, params)
+
+    def _build_url(self, base_url, extra_params):
+        separator = '&' if '?' in base_url else '?'
+        return base_url + separator + '&'.join(extra_params)
+
+    def build_policy(
+        self, resource, date_less_than, date_greater_than=None, ip_address=None
+    ):
+        """A helper to build policy.
+
+        :type resource: str
+        :param resource: The URL or the stream filename of the protected object
+
+        :type date_less_than: datetime
+        :param date_less_than: The URL will expire after the time has passed
+
+        :type date_greater_than: datetime
+        :param date_greater_than: The URL will not be valid until this time
+
+        :type ip_address: str
+        :param ip_address: Use 'x.x.x.x' for an IP, or 'x.x.x.x/x' for a subnet
+
+        :rtype: str
+        :return: The policy in a compact string.
+        """
+        # Note:
+        # 1. Order in canned policy is significant. Special care has been taken
+        #    to ensure the output will match the order defined by the document.
+        #    There is also a test case to ensure that order.
+        #    SEE: http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/private-content-creating-signed-url-canned-policy.html#private-content-canned-policy-creating-policy-statement
+        # 2. Albeit the order in custom policy is not required by CloudFront,
+        #    we still use OrderedDict internally to ensure the result is stable
+        #    and also matches canned policy requirement.
+        #    SEE: http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/private-content-creating-signed-url-custom-policy.html
+        moment = int(datetime2timestamp(date_less_than))
+        condition = OrderedDict({"DateLessThan": {"AWS:EpochTime": moment}})
+        if ip_address:
+            if '/' not in ip_address:
+                ip_address += '/32'
+            condition["IpAddress"] = {"AWS:SourceIp": ip_address}
+        if date_greater_than:
+            moment = int(datetime2timestamp(date_greater_than))
+            condition["DateGreaterThan"] = {"AWS:EpochTime": moment}
+        ordered_payload = [('Resource', resource), ('Condition', condition)]
+        custom_policy = {"Statement": [OrderedDict(ordered_payload)]}
+        return json.dumps(custom_policy, separators=(',', ':'))
+
+    def _url_b64encode(self, data):
+        # Required by CloudFront. See also:
+        # http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/private-content-linux-openssl.html
+        return (
+            base64.b64encode(data)
+            .replace(b'+', b'-')
+            .replace(b'=', b'_')
+            .replace(b'/', b'~')
+        )
+
+
+def add_generate_db_auth_token(class_attributes, **kwargs):
+    class_attributes['generate_db_auth_token'] = generate_db_auth_token
+
+
+def add_dsql_generate_db_auth_token_methods(class_attributes, **kwargs):
+    class_attributes['generate_db_connect_auth_token'] = (
+        dsql_generate_db_connect_auth_token
+    )
+    class_attributes['generate_db_connect_admin_auth_token'] = (
+        dsql_generate_db_connect_admin_auth_token
+    )
+
+
+def generate_db_auth_token(self, DBHostname, Port, DBUsername, Region=None):
+    """Generates an auth token used to connect to a db with IAM credentials.
+
+    :type DBHostname: str
+    :param DBHostname: The hostname of the database to connect to.
+
+    :type Port: int
+    :param Port: The port number the database is listening on.
+
+    :type DBUsername: str
+    :param DBUsername: The username to log in as.
+
+    :type Region: str
+    :param Region: The region the database is in. If None, the client
+        region will be used.
+
+    :return: A presigned url which can be used as an auth token.
+    """
+    region = Region
+    if region is None:
+        region = self.meta.region_name
+
+    params = {
+        'Action': 'connect',
+        'DBUser': DBUsername,
+    }
+
+    request_dict = {
+        'url_path': '/',
+        'query_string': '',
+        'headers': {},
+        'body': params,
+        'method': 'GET',
+    }
+
+    # RDS requires that the scheme not be set when sent over. This can cause
+    # issues when signing because the Python url parsing libraries follow
+    # RFC 1808 closely, which states that a netloc must be introduced by `//`.
+    # Otherwise the url is presumed to be relative, and thus the whole
+    # netloc would be treated as a path component. To work around this we
+    # introduce https here and remove it once we're done processing it.
+    scheme = 'https://'
+    endpoint_url = f'{scheme}{DBHostname}:{Port}'
+    prepare_request_dict(request_dict, endpoint_url)
+    presigned_url = self._request_signer.generate_presigned_url(
+        operation_name='connect',
+        request_dict=request_dict,
+        region_name=region,
+        expires_in=900,
+        signing_name='rds-db',
+    )
+    return presigned_url[len(scheme) :]
+
+
+def _dsql_generate_db_auth_token(
+    self, Hostname, Action, Region=None, ExpiresIn=900
+):
+    """Generate a DSQL database token for an arbitrary action.
+
+    :type Hostname: str
+    :param Hostname: The DSQL endpoint host name.
+
+    :type Action: str
+    :param Action: Action to perform on the cluster (DbConnectAdmin or DbConnect).
+
+    :type Region: str
+    :param Region: The AWS region where the DSQL Cluster is hosted. If None, the client region will be used.
+
+    :type ExpiresIn: int
+    :param ExpiresIn: The token expiry duration in seconds (default is 900 seconds).
+
+    :return: A presigned url which can be used as an auth token.
+    """
+    possible_actions = ("DbConnect", "DbConnectAdmin")
+
+    if Action not in possible_actions:
+        raise ParamValidationError(
+            report=f"Received {Action} for action but expected one of: {', '.join(possible_actions)}"
+        )
+
+    if Region is None:
+        Region = self.meta.region_name
+
+    request_dict = {
+        'url_path': '/',
+        'query_string': '',
+        'headers': {},
+        'body': {
+            'Action': Action,
+        },
+        'method': 'GET',
+    }
+    scheme = 'https://'
+    endpoint_url = f'{scheme}{Hostname}'
+    prepare_request_dict(request_dict, endpoint_url)
+    presigned_url = self._request_signer.generate_presigned_url(
+        operation_name=Action,
+        request_dict=request_dict,
+        region_name=Region,
+        expires_in=ExpiresIn,
+        signing_name='dsql',
+    )
+    return presigned_url[len(scheme) :]
+
+
+def dsql_generate_db_connect_auth_token(
+    self, Hostname, Region=None, ExpiresIn=900
+):
+    """Generate a DSQL database token for the "DbConnect" action.
+
+    :type Hostname: str
+    :param Hostname: The DSQL endpoint host name.
+
+    :type Region: str
+    :param Region: The AWS region where the DSQL Cluster is hosted. If None, the client region will be used.
+
+    :type ExpiresIn: int
+    :param ExpiresIn: The token expiry duration in seconds (default is 900 seconds).
+
+    :return: A presigned url which can be used as an auth token.
+    """
+    return _dsql_generate_db_auth_token(
+        self, Hostname, "DbConnect", Region, ExpiresIn
+    )
+
+
+def dsql_generate_db_connect_admin_auth_token(
+    self, Hostname, Region=None, ExpiresIn=900
+):
+    """Generate a DSQL database token for the "DbConnectAdmin" action.
+
+    :type Hostname: str
+    :param Hostname: The DSQL endpoint host name.
+
+    :type Region: str
+    :param Region: The AWS region where the DSQL Cluster is hosted. If None, the client region will be used.
+
+    :type ExpiresIn: int
+    :param ExpiresIn: The token expiry duration in seconds (default is 900 seconds).
+
+    :return: A presigned url which can be used as an auth token.
+    """
+    return _dsql_generate_db_auth_token(
+        self, Hostname, "DbConnectAdmin", Region, ExpiresIn
+    )
+
+
+class S3PostPresigner:
+    def __init__(self, request_signer):
+        self._request_signer = request_signer
+
+    def generate_presigned_post(
+        self,
+        request_dict,
+        fields=None,
+        conditions=None,
+        expires_in=3600,
+        region_name=None,
+    ):
+        """Generates the url and the form fields used for a presigned s3 post
+
+        :type request_dict: dict
+        :param request_dict: The prepared request dictionary returned by
+            ``botocore.awsrequest.prepare_request_dict()``
+
+        :type fields: dict
+        :param fields: A dictionary of prefilled form fields to build on top
+            of.
+
+        :type conditions: list
+        :param conditions: A list of conditions to include in the policy. Each
+            element can be either a list or a structure. For example:
+
+            .. code:: python
+
+                [
+                    {"acl": "public-read"},
+                    {"bucket": "amzn-s3-demo-bucket"},
+                    ["starts-with", "$key", "mykey"]
+                ]
+
+        :type expires_in: int
+        :param expires_in: The number of seconds the presigned post is valid
+            for.
+
+        :type region_name: string
+        :param region_name: The region name to sign the presigned post to.
+
+        :rtype: dict
+        :returns: A dictionary with two elements: ``url`` and ``fields``.
+            Url is the url to post to. Fields is a dictionary filled with
+            the form fields and respective values to use when submitting the
+            post. For example:
+
+            .. code:: python
+
+                {
+                    'url': 'https://amzn-s3-demo-bucket.s3.amazonaws.com',
+                    'fields': {
+                        'acl': 'public-read',
+                        'key': 'mykey',
+                        'signature': 'mysignature',
+                        'policy': 'mybase64 encoded policy'
+                    }
+                }
+        """
+        if fields is None:
+            fields = {}
+
+        if conditions is None:
+            conditions = []
+
+        # Create the policy for the post.
+        policy = {}
+
+        # Create an expiration date for the policy
+        datetime_now = datetime.datetime.utcnow()
+        expire_date = datetime_now + datetime.timedelta(seconds=expires_in)
+        policy['expiration'] = expire_date.strftime(botocore.auth.ISO8601)
+
+        # Append all of the conditions that the user supplied.
+        policy['conditions'] = []
+        for condition in conditions:
+            policy['conditions'].append(condition)
+
+        # Store the policy and the fields in the request for signing
+        request = create_request_object(request_dict)
+        request.context['s3-presign-post-fields'] = fields
+        request.context['s3-presign-post-policy'] = policy
+
+        self._request_signer.sign(
+            'PutObject', request, region_name, 'presign-post'
+        )
+        # Return the url and the fields for th form to post.
+        return {'url': request.url, 'fields': fields}
+
+
+def add_generate_presigned_url(class_attributes, **kwargs):
+    class_attributes['generate_presigned_url'] = generate_presigned_url
+
+
+def generate_presigned_url(
+    self, ClientMethod, Params=None, ExpiresIn=3600, HttpMethod=None
+):
+    """Generate a presigned url given a client, its method, and arguments
+
+    :type ClientMethod: string
+    :param ClientMethod: The client method to presign for
+
+    :type Params: dict
+    :param Params: The parameters normally passed to
+        ``ClientMethod``.
+
+    :type ExpiresIn: int
+    :param ExpiresIn: The number of seconds the presigned url is valid
+        for. By default it expires in an hour (3600 seconds)
+
+    :type HttpMethod: string
+    :param HttpMethod: The http method to use on the generated url. By
+        default, the http method is whatever is used in the method's model.
+
+    :returns: The presigned url
+    """
+    client_method = ClientMethod
+    params = Params
+    if params is None:
+        params = {}
+    expires_in = ExpiresIn
+    http_method = HttpMethod
+    context = {
+        'is_presign_request': True,
+        'use_global_endpoint': _should_use_global_endpoint(self),
+    }
+
+    request_signer = self._request_signer
+
+    try:
+        operation_name = self._PY_TO_OP_NAME[client_method]
+    except KeyError:
+        raise UnknownClientMethodError(method_name=client_method)
+
+    operation_model = self.meta.service_model.operation_model(operation_name)
+    params = self._emit_api_params(
+        api_params=params,
+        operation_model=operation_model,
+        context=context,
+    )
+    bucket_is_arn = ArnParser.is_arn(params.get('Bucket', ''))
+    (
+        endpoint_url,
+        additional_headers,
+        properties,
+    ) = self._resolve_endpoint_ruleset(
+        operation_model,
+        params,
+        context,
+        ignore_signing_region=(not bucket_is_arn),
+    )
+
+    request_dict = self._convert_to_request_dict(
+        api_params=params,
+        operation_model=operation_model,
+        endpoint_url=endpoint_url,
+        context=context,
+        headers=additional_headers,
+        set_user_agent_header=False,
+    )
+
+    # Switch out the http method if user specified it.
+    if http_method is not None:
+        request_dict['method'] = http_method
+
+    # Generate the presigned url.
+    return request_signer.generate_presigned_url(
+        request_dict=request_dict,
+        expires_in=expires_in,
+        operation_name=operation_name,
+    )
+
+
+def add_generate_presigned_post(class_attributes, **kwargs):
+    class_attributes['generate_presigned_post'] = generate_presigned_post
+
+
+def generate_presigned_post(
+    self, Bucket, Key, Fields=None, Conditions=None, ExpiresIn=3600
+):
+    """Builds the url and the form fields used for a presigned s3 post
+
+    :type Bucket: string
+    :param Bucket: The name of the bucket to presign the post to. Note that
+        bucket related conditions should not be included in the
+        ``conditions`` parameter.
+
+    :type Key: string
+    :param Key: Key name, optionally add ${filename} to the end to
+        attach the submitted filename. Note that key related conditions and
+        fields are filled out for you and should not be included in the
+        ``Fields`` or ``Conditions`` parameter.
+
+    :type Fields: dict
+    :param Fields: A dictionary of prefilled form fields to build on top
+        of. Elements that may be included are acl, Cache-Control,
+        Content-Type, Content-Disposition, Content-Encoding, Expires,
+        success_action_redirect, redirect, success_action_status,
+        and x-amz-meta-.
+
+        Note that if a particular element is included in the fields
+        dictionary it will not be automatically added to the conditions
+        list. You must specify a condition for the element as well.
+
+    :type Conditions: list
+    :param Conditions: A list of conditions to include in the policy. Each
+        element can be either a list or a structure. For example:
+
+        .. code:: python
+
+            [
+                {"acl": "public-read"},
+                ["content-length-range", 2, 5],
+                ["starts-with", "$success_action_redirect", ""]
+            ]
+
+        Conditions that are included may pertain to acl,
+        content-length-range, Cache-Control, Content-Type,
+        Content-Disposition, Content-Encoding, Expires,
+        success_action_redirect, redirect, success_action_status,
+        and/or x-amz-meta-.
+
+        Note that if you include a condition, you must specify
+        a valid value in the fields dictionary as well. A value will
+        not be added automatically to the fields dictionary based on the
+        conditions.
+
+    :type ExpiresIn: int
+    :param ExpiresIn: The number of seconds the presigned post
+        is valid for.
+
+    :rtype: dict
+    :returns: A dictionary with two elements: ``url`` and ``fields``.
+        Url is the url to post to. Fields is a dictionary filled with
+        the form fields and respective values to use when submitting the
+        post. For example:
+
+        .. code:: python
+
+            {
+                'url': 'https://amzn-s3-demo-bucket.s3.amazonaws.com',
+                'fields': {
+                    'acl': 'public-read',
+                    'key': 'mykey',
+                    'signature': 'mysignature',
+                    'policy': 'mybase64 encoded policy'
+                }
+            }
+    """
+    bucket = Bucket
+    key = Key
+    fields = Fields
+    conditions = Conditions
+    expires_in = ExpiresIn
+
+    if fields is None:
+        fields = {}
+    else:
+        fields = fields.copy()
+
+    if conditions is None:
+        conditions = []
+
+    context = {
+        'is_presign_request': True,
+        'use_global_endpoint': _should_use_global_endpoint(self),
+    }
+
+    post_presigner = S3PostPresigner(self._request_signer)
+
+    # We choose the CreateBucket operation model because its url gets
+    # serialized to what a presign post requires.
+    operation_model = self.meta.service_model.operation_model('CreateBucket')
+    params = self._emit_api_params(
+        api_params={'Bucket': bucket},
+        operation_model=operation_model,
+        context=context,
+    )
+    bucket_is_arn = ArnParser.is_arn(params.get('Bucket', ''))
+    (
+        endpoint_url,
+        additional_headers,
+        properties,
+    ) = self._resolve_endpoint_ruleset(
+        operation_model,
+        params,
+        context,
+        ignore_signing_region=(not bucket_is_arn),
+    )
+
+    request_dict = self._convert_to_request_dict(
+        api_params=params,
+        operation_model=operation_model,
+        endpoint_url=endpoint_url,
+        context=context,
+        headers=additional_headers,
+        set_user_agent_header=False,
+    )
+
+    # Append that the bucket name to the list of conditions.
+    conditions.append({'bucket': bucket})
+
+    # If the key ends with filename, the only constraint that can be
+    # imposed is if it starts with the specified prefix.
+    if key.endswith('${filename}'):
+        conditions.append(["starts-with", '$key', key[: -len('${filename}')]])
+    else:
+        conditions.append({'key': key})
+
+    # Add the key to the fields.
+    fields['key'] = key
+
+    return post_presigner.generate_presigned_post(
+        request_dict=request_dict,
+        fields=fields,
+        conditions=conditions,
+        expires_in=expires_in,
+    )
+
+
+def _should_use_global_endpoint(client):
+    if client.meta.partition != 'aws':
+        return False
+    s3_config = client.meta.config.s3
+    if s3_config:
+        if s3_config.get('use_dualstack_endpoint', False):
+            return False
+        if (
+            s3_config.get('us_east_1_regional_endpoint') == 'regional'
+            and client.meta.config.region_name == 'us-east-1'
+        ):
+            return False
+        if s3_config.get('addressing_style') == 'virtual':
+            return False
+    return True