Abstract: A system that provides responses to requests obtains a key that is used to digitally sign the request. The key is derived from information that is shared with a requestor to which the response is sent. The requestor derives, using the shared information, derives a key usable to verify the digital signature of the response, thereby enabling the requestor to operate in accordance with whether the digital signature of the response matches the response.

Abstract: Techniques are described for providing managed computer networks, such as for managed virtual computer networks overlaid on one or more other underlying computer networks. In some situations, the techniques include facilitating replication of a primary computing node that is actively participating in a managed computer network, such as by maintaining one or more other computing nodes in the managed computer network as replicas, and using such replica computing nodes in various manners. For example, a particular managed virtual computer network may span multiple broadcast domains of an underlying computer network, and a particular primary computing node and a corresponding remote replica computing node of the managed virtual computer network may be implemented in distinct broadcast domains of the underlying computer network, with the replica computing node being used to transparently replace the primary computing node in the virtual computer network if the primary computing node becomes unavailable.

Abstract: Custom policies are definable for use in a system that enforces policies. A user, for example, may author a policy using a policy language and transmit the system through an application programming interface call. The custom policies may specify conditions for computing environment attestations that are provided with requests to the system. When a custom policy applies to a request, the system may determine whether information in the attestation is sufficient for the request to be fulfilled.

Abstract: Techniques are described for enabling users to create and configure request-based policies used by a data storage system to generate custom responses to particular types of requests for users' stored data objects. The request-based policies include rules used to identify types of requests for data objects and corresponding types of responses to be generated responsive to detecting such requests. The types of responses that can be specified in such policies include responses other than simply returning a requested data object or denying a request. For example, a rule for certain types of responses can instruct the data storage system to return a dynamically generated data object, another rule can instruct the system to return a different data object than the one requested, and so forth.

Abstract: Techniques are described for monitoring and analyzing input/output (I/O) messages for patterns indicative of ransomware attacks affecting computer systems of a cloud provider, and for performing various remediation actions to mitigate data loss once a potential ransomware attack is detected. The monitoring of I/O activity for such patterns is performed at least in part by I/O proxy devices coupled to computer systems of a cloud provider network, where an I/O proxy device is interposed in the I/O path between guest operating systems running on a computer system and storage devices to which I/O messages are destined. An I/O proxy device can analyze I/O messages for patterns indicative of potential ransomware attacks by monitoring for anomalous I/O patterns which may, e.g., be indicative of a malicious process attempting to encrypt or otherwise render in accessible a significant portion of one or more storage volumes as part of a ransomware attack.

Abstract: Virtual resources may be provisioned in a manner that is aware of, and respects, underlying implementation resource boundaries. A customer of the virtual resource provider may specify that particular virtual resources are to be implemented with implementation resources that are dedicated to the customer. Dedicating an implementation resource to a particular customer of a virtual resource provider may establish one or more information barriers between the particular customer and other customers of the virtual resource provider. Implementation resources may require transition procedures, including custom transition procedures, to enter and exit dedicated implementation resource pools. Costs corresponding to active and inactive implementation resources in a dedicated pools associated with a particular customer may be accounted for, and presented to, the customer in a variety of ways including explicit, adjusted per customer and adjusted per type of virtual resource and/or implementation resource.

Abstract: An encoding of a cryptographic key is obtained in a form of an encrypted key. Request is provided to a service provider including a fulfillment involving performing a cryptographic operation on data. Upon fulfillment of the request, a response is then received which indicates the fulfillment of the request.

Abstract: Techniques are described for providing a web cookie firewall application capable of monitoring and controlling the use of web cookies at computing devices. The web cookie firewall application uses web cookie security policies to selectively allow or prohibit the storage or use of individual web cookies or types of web cookies. For example, web cookie security permissions can be defined by such policies to permit or deny the storage or use of web cookies associated with certain website domains, to permit or deny the storage or use of defined types of cookies, or to control access to web cookies based on other attributes. The web cookie firewall application can be implemented as a standalone application, as a web browser plugin or extension, or as any other type of software application that it is capable of monitoring and controlling the use web cookies on a computing device.

Abstract: A system comprises a data storage service includes a web service interface operating as a proxy to the data storage service. Data obtained at the data storage service is analyzed by one or more criteria of a data loss prevention policy, the data is encrypted by a key that is inaccessible to a remote service, and then the encrypted data is transmitted to the remote service.

Abstract: Techniques are described for monitoring and analyzing input/output (I/O) messages for patterns indicative of ransomware attacks affecting computer systems of a cloud provider, and for performing various remediation actions to mitigate data loss once a potential ransomware attack is detected. The monitoring of I/O activity for such patterns is performed at least in part by I/O proxy devices coupled to computer systems of a cloud provider network, where an I/O proxy device is interposed in the I/O path between guest operating systems running on a computer system and storage devices to which I/O messages are destined. An I/O proxy device can analyze I/O messages for patterns indicative of potential ransomware attacks by monitoring for anomalous I/O patterns which may, e.g., be indicative of a malicious process attempting to encrypt or otherwise render in accessible a significant portion of one or more storage volumes as part of a ransomware attack.

Abstract: An application programming interface gateway service generates an application programming interface that, in various examples, allows client applications to access database functionality without maintaining active database connections, managing database credentials, or providing SQL code. The application programming interface maintains state information between invocations that allows for improved database performance. The state information may include SQL statements and subroutines, compiled SQL code, database credentials, active database connections, and connection pools. When invoked by a client application, the application programming interface may select an active database connection from a connection pool based at least in part on the activity history of each connection in the connection pool so that the expected cache performance of the database may be improved.

Abstract: Techniques are described for enabling users of cloud provider services to verify, via cryptographic attestation, that trusted “enclaves” are used to process user data during limited points in time at which user data may be unencrypted or otherwise vulnerable. A cloud provider service processes requests involving user data at least in part using an enclave, where an enclave includes a virtual machine running on isolated computing resources of a host computing device managed by the cloud provider. The enclave, for example, can include an application that performs operations such as decrypting user data included in requests sent to a service (e.g., user data encrypted as part of a Transport Layer Security (TLS) connection established between the service and a client computing device), obtaining user-specific encryption keys from a key management service or other source, encrypting the user data using the encryption keys, and forwarding the encrypted data for further processing.

Abstract: Techniques are described for providing virtual networking functionality for managed computer networks. In some situations, a user may configure or otherwise specify a logical network topology for a managed computer network with multiple computing nodes that includes one or more virtual networking devices each associated with a specified group of the multiple computing nodes. Corresponding networking functionality may be provided for communications between the multiple computing nodes by emulating functionality that would be provided by the networking devices if they were physically present and configured to support the specified network topology. In some situations, the managed computer network is a virtual computer network overlaid on a substrate network, and the networking device functionality emulating includes receiving routing communications directed to the networking devices and using included routing information to update the specified network topology for the managed computer network.

Abstract: Techniques are described for monitoring and analyzing input/output (I/O) messages for patterns indicative of ransomware attacks affecting computer systems of a cloud provider, and for performing various remediation actions to mitigate data loss once a potential ransomware attack is detected. The monitoring of I/O activity for such patterns is performed at least in part by I/O proxy devices coupled to computer systems of a cloud provider network, where an I/O proxy device is interposed in the I/O path between guest operating systems running on a computer system and storage devices to which I/O messages are destined. An I/O proxy device can analyze I/O messages for patterns indicative of potential ransomware attacks by monitoring for anomalous I/O patterns which may, e.g., be indicative of a malicious process attempting to encrypt or otherwise render in accessible a significant portion of one or more storage volumes as part of a ransomware attack.

Abstract: Systems and methods utilize network destination identifiers, such as IP addresses, that are simultaneously advertised from multiple locations. The network destination identifiers may be announced in multiple geographic regions. Network traffic routed to devices advertising the network destination identifiers may be routed to appropriate endpoints. When a device receives such traffic, it may send the traffic to an endpoint in a network served by the device. In some instances, such as when such an endpoint is not available, the network traffic may be sent to another network that is served by another device that advertises the network destination identifiers.

Abstract: A connected device at a client network implements a local data classification service for classifying data based on a data classification service of a remote provider network. The local data classification service receives a request to classify data at one or more data sources of the client network. The request is initiated from a client device of the client network according to a management interface for a data classification service of a remote provider network (e.g., using the same API request used by the remote classification service). The local data classification service obtains at least some of the data from the one or more data sources of the client network. The local data classification service classifies the obtained data according to different types of sensitivity using the data classification engine in the execution environment without the data being exposed outside of a data isolation boundary of the client network.

Abstract: Techniques are described for providing logical networking functionality for managed computer networks, such as for virtual computer networks provided on behalf of users or other entities. In some situations, a user may configure or otherwise specify a network topology for a virtual computer network, such as a logical network topology that separates multiple computing nodes of the virtual computer network into multiple logical sub-networks and/or that specifies one or more logical networking devices for the virtual computer network. After a network topology is specified for a virtual computer network, logical networking functionality corresponding to the network topology may be provided in various manners, such as without physically implementing the network topology for the virtual computer network. In some situations, the computing nodes may include virtual machine nodes hosted on one or more physical computing machines or systems, such as by or on behalf of one or more users.

Abstract: Techniques are described for providing managed computer networks, such as for managed virtual computer networks overlaid on one or more other underlying computer networks. In some situations, the techniques include facilitating replication of a primary computing node that is actively participating in a managed computer network, such as by maintaining one or more other computing nodes in the managed computer network as replicas, and using such replica computing nodes in various manners. For example, a particular managed virtual computer network may span multiple broadcast domains of an underlying computer network, and a particular primary computing node and a corresponding remote replica computing node of the managed virtual computer network may be implemented in distinct broadcast domains of the underlying computer network, with the replica computing node being used to transparently replace the primary computing node in the virtual computer network if the primary computing node becomes unavailable.

Abstract: Techniques are described for managing communications between multiple computing nodes, such as for computing nodes that are part of managed virtual computer networks provided on behalf of users or other entities. In some situations, one or more of the computing nodes of a managed virtual computer network is configured to perform actions to extend capabilities of the managed virtual computer network to other computing nodes that are not part of the managed virtual computer network, such as by forwarding communications between computing nodes of the managed virtual computer network and the other external computing nodes so as to enable the other external computing nodes to participate in the managed virtual computer network. In some situations, the computing nodes may include virtual machine nodes hosted on one or more physical computing machines or systems, such as by or on behalf of one or more users.

Abstract: Techniques are described for providing virtual networking functionality for managed computer networks. In some situations, a user may configure or otherwise specify a logical network topology for a managed computer network with multiple computing nodes that includes one or more virtual networking devices each associated with a specified group of the multiple computing nodes. Corresponding networking functionality may be provided for communications between the multiple computing nodes by emulating functionality that would be provided by the networking devices if they were physically present and configured to support the specified network topology. In some situations, the managed computer network is a virtual computer network overlaid on a substrate network, and the networking device functionality emulating includes receiving routing communications directed to the networking devices and using included routing information to update the specified network topology for the managed computer network.