Oracle Corporation

phil.hunt@yahoo.com

Microsoft

mbj@microsoft.com http://self-issued.info/

Google

wdenniss@google.com

Cisco

morteza.ansari@cisco.com

Security Security Events Working Group Identity Security Event Token Claims JSON JSON Web Token JWT Internet-Draft This specification defines the Security Event Token (SET) data structure. A SET describes statements of fact from the perspective of an issuer about a subject. These statements of fact represent an event that occurred directly to or about a security subject, for example, a statement about the issuance or revocation of a token on behalf of a subject. This specification is intended to enable representing security- and identity-related events. A SET is a JSON Web Token (JWT), which can be optionally signed and/or encrypted. SETs can be distributed via protocols such as HTTP.

This specification defines an extensible Security Event Token (SET) data structure, which can be exchanged using protocols such as HTTP. The specification builds on the JSON Web Token (JWT) format in order to provide a self-contained token that can be optionally signed using JSON Web Signature (JWS) and/or encrypted using JSON Web Encryption (JWE) . This specification profiles the use of JWT for the purpose of issuing Security Event Tokens (SETs). This specification defines a base format used by profiling specifications to define actual events and their meanings. This specification uses non-normative example events to demonstrate how events can be constructed. This specification is scoped to security- and identity-related events. While Security Event Tokens may be used for other purposes, the specification only considers security and privacy concerns relevant to identity and personal information. Security events are not commands issued between parties. A SET describes statements of fact from the perspective of an issuer about a subject (e.g., a web resource, token, IP address, the issuer itself). These statements of fact represent a logical event that occurred directly to or about a security subject, for example, a statement about the issuance or revocation of a token on behalf of a subject. A security subject may be permanent (e.g., a user account) or temporary (e.g., an HTTP session) in nature. A state change could describe a direct change of entity state, an implicit change of state, or other higher-level security statements such as: The creation, modification, removal of a resource. The resetting or suspension of an account. The revocation of a security token prior to its expiry. The logout of a user session. Or, An indication that a user has been given control of an email identifier that was previously controlled by another user. While subject state changes are often triggered by a user agent or security subsystem, the issuance and transmission of an event may occur asynchronously and in a back channel to the action that caused the change that generated the security event. Subsequently, a SET recipient, having received a SET, validates and interprets the received SET and takes its own independent actions, if any. For example, having been informed of a personal identifier being associated with a different security subject (e.g., an email address is being used by someone else), the SET recipient may choose to ensure that the new user is not granted access to resources associated with the previous user. Or, the SET recipient may not have any relationship with the subject, and no action is taken. While SET recipients will often take actions upon receiving SETs, security events cannot be assumed to be commands or requests. The intent of this specification is to define a syntax for statements of fact that SET recipients may interpret for their own purposes.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here. For purposes of readability, examples are not URL encoded. Implementers MUST percent encode URLs as described in Section 2.1 of . Throughout this document, all figures MAY contain spaces and extra line-wrapping for readability and space limitations. Similarly, some URIs contained within examples have been shortened for space and readability reasons.

The following definitions are used with SETs: A SET is a JWT conforming to this specification. A service provider that creates SETs to be sent to other service providers known as SET recipients. A SET recipient is an entity that receives SETs through some distribution method. A SET recipient is the same entity referred as a "recipient" in or "receiver" in related specifications. A SET describes an event or state change that has occurred to a subject. A subject might, for instance, be a principal (e.g., Section 4.1.2 of ), a web resource, an entity such as an IP address, or the issuer of the SET. A member name for an element of the JSON object that is the value of the events claim in a SET. This member name MUST be a URI. A member value for an element of the JSON object that is the value of the events claim in a SET. This member value MUST be a JSON object. A specification that profiles the SET data structure to define one or more specific event types and their associated claims and processing rules.

A SET is a JWT data structure that represents one or more related aspects of a security event that occurred to a subject. The JWT Claims Set in a SET has the following structure: The top-level claims in the JWT Claims Set are called the SET "envelope". Some of these claims are present in every SET; others will be specific to particular SET profiles or profile families. Claims in the envelope SHOULD be registered in the "JSON Web Token Claims" registry or be Public Claims or Private Claims, as defined in . Envelope claims that are profiled and defined in this specification are used to validate the SET and provide information about the event data included in the SET. The claim events contains the event identifiers and event-specific data expressed about the security subject. The envelope MAY include event-specific or profile-specific data. The events claim value MUST be a JSON object that contains at least one member. Each member of the events JSON object is a name/value pair. The JSON member name is a URI string value, which is the event identifier, and the corresponding value is a JSON object known as the event "payload". The payload JSON object contains claims that pertain to that event identifier and need not be registered as JWT claims. These claims are defined by the profiling specification that defines the event. An event with no payload claims SHALL be represented as the empty JSON object ({}). When multiple event identifiers are contained in a SET, they represent multiple aspects of the same state transition that occurred to the security subject. They are not intended to be used to aggregate distinct events about the same subject. Beyond this, the interpretation of SETs containing multiple event identifiers is out of scope for this specification; profiling specifications MAY define their own rules regarding their use of SETs containing multiple event identifiers, as described in . Possible uses of multiple values include, but are not limited to: Values to provide classification information (e.g., threat type or level). Additions to existing event representations. Values used to link potential series of events. Specific-purpose event URIs used between particular SET issuers and SET recipients.

This section illustrates several possible uses of SETs through non-normative examples.

The following example shows the JWT Claims Set for a hypothetical SCIM password reset SET. Such a SET might be used by a receiver as a trigger to reset active user-agent sessions related to the identified user.

{ "iss": "https://scim.example.com", "iat": 1458496025, "jti": "3d0c3cf797584bd193bd0fb1bd4e7d30", "aud": [ "https://jhub.example.com/Feeds/98d52461fa5bbc879593b7754", "https://jhub.example.com/Feeds/5d7604516b1d08641d7676ee7" ], "sub": "https://scim.example.com/Users/44f6142df96bd6ab61e7521d9", "events": { "urn:ietf:params:scim:event:passwordReset": { "id": "44f6142df96bd6ab61e7521d9"}, "https://example.com/scim/event/passwordResetExt": { "resetAttempts": 5} } }

The JWT Claims Set usage consists of: The events claim specifying the hypothetical SCIM URN (urn:ietf:params:scim:event:passwordReset) for a password reset, and a second value, https://example.com/scim/event/passwordResetExt, that is used to provide additional event information such as the current count of resets. The iss claim, denoting the SET issuer. The sub claim, specifying the SCIM resource URI that was affected. The aud claim, specifying the intended audiences for the event. (The syntax of the aud claim is defined in Section 4.1.3 of .) The SET contains two event payloads: The id claim represents SCIM's unique identifier for a subject. The second payload identified by https://example.com/scim/event/passwordResetExt) and the payload claim resetAttempts conveys the current count of reset attempts. In this example, while the count is a simple factual statement for the issuer, the meaning of the value (a count) is up to the receiver. As an example, such a value might be used by the receiver to infer increasing risk. In this example, the SCIM event indicates that a password has been updated and the current password reset count is 5. Notice that the value for resetAttempts is in the event payload of an event used to convey this information.

Here is another example JWT Claims Set for a security event token, this one for a Logout Token: { "iss": "https://server.example.com", "sub": "248289761001", "aud": "s6BhdRkqt3", "iat": 1471566154, "jti": "bWJq", "sid": "08a5019c-17e1-4977-8f42-65a12843ea02", "events": { "http://schemas.openid.net/event/backchannel-logout": {} } }

Note that the above SET has an empty JSON object and uses the JWT claims sub and sid to identify the subject that was logged out. At the time of this writing, this example corresponds to the logout token defined in the OpenID Connect Back-Channel Logout 1.0 specification.

In the following example JWT Claims Set, a fictional medical service collects consent for medical actions and notifies other parties. The individual for whom consent is identified was originally authenticated via OpenID Connect. In this case, the issuer of the security event is an application rather than the OpenID provider: { "iss": "https://my.med.example.org", "iat": 1458496025, "jti": "fb4e75b5411e4e19b6c0fe87950f7749", "aud": [ "https://rp.example.com" ], "events": { "https://openid.net/heart/specs/consent.html": { "iss": "https://connect.example.com", "sub": "248289761001", "consentUri": [ "https://terms.med.example.org/labdisclosure.html#Agree" ] } } }

In the above example, the attribute iss contained within the payload for the event https://openid.net/heart/specs/consent.html refers to the issuer of the security subject (sub) rather than the SET issuer https://my.med.example.org. They are distinct from the top-level value of iss, which always refers to the issuer of the event -- a medical consent service that is a relying party to the OpenID Provider.

The following example JWT Claims Set is for an account disabled event. This example was taken from a working draft of the RISC events specification, where RISC is the OpenID RISC (Risk and Incident Sharing and Coordination) working group . The example is subject to change. { "iss": "https://idp.example.com/", "jti": "756E69717565206964656E746966696572", "iat": 1508184845, "aud": "636C69656E745F6964", "events": { "http://schemas.openid.net/secevent/risc/event-type/\ account-disabled": { "subject": { "subject_type": "iss-sub", "iss": "https://idp.example.com/", "sub": "7375626A656374" }, "reason": "hijacking", "cause-time": 1508012752 } } }

Notice that parameters to the event are included in the event payload, in this case, the reason and cause-time values. The subject of the event is identified using the subject payload value, which itself is a JSON object.

The following claims from are profiled for use in SETs: As defined by Section 4.1.1 of , this claim contains a string identifying the service provider publishing the SET (the issuer). In some cases, the issuer of the SET will not be the issuer associated with the security subject of the SET. Therefore, implementers cannot assume that the issuers are the same unless the profiling specification specifies that they are for SETs conforming to that profile. This claim is REQUIRED. As defined by Section 4.1.6 of , this claim contains a value representing when the SET was issued. This claim is REQUIRED. As defined by Section 4.1.7 of , this claim contains a unique identifier for the SET. The identifier MUST be unique within a particular event feed and MAY be used by clients to track whether a particular SET has already been received. This claim is REQUIRED. As defined by Section 4.1.3 of , this claim contains one or more audience identifiers for the SET. This claim is RECOMMENDED. As defined by Section 4.1.2 of , this claim contains a StringOrURI value representing the principal that is the subject of the SET. This is usually the entity whose "state" was changed. For example: an IP Address was added to a black list; a URI representing a user resource that was modified; or, a token identifier (e.g. jti) for a revoked token. If used, the profiling specification MUST define the content and format semantics for the value. This claim is OPTIONAL, as the principal for any given profile may already be identified without the inclusion of a subject claim. Note that some SET profiles MAY choose to convey event subject information in the event payload (either using the sub member name or another name), particularly if the subject information is relative to issuer information that is also conveyed in the event payload, which may be the case for some identity SET profiles. As defined by Section 4.1.4 of , this claim is the time after which the JWT MUST NOT be accepted for processing. In the context of a SET however, this notion does not typically apply, since a SET represents something that has already occurred and is historical in nature. Therefore, its use is NOT RECOMMENDED. (Also, see for additional reasons not to use the exp claim in some SET use cases.) The following new claims are defined by this specification: This claim contains a set of event statements that each provide information describing a single logical event that has occurred about a security subject (e.g., a state change to the subject). Multiple event identifiers with the same value MUST NOT be used. The events claim MUST NOT be used to express multiple independent logical events. The value of the events claim is a JSON object whose members are name/value pairs whose names are URIs identifying the event statements being expressed. Event identifiers SHOULD be stable values (e.g., a permanent URL for an event specification). For each name present, the corresponding value MUST be a JSON object. The JSON object MAY be an empty object ({}), or it MAY be a JSON object containing data described by the profiling specification. An OPTIONAL string value that represents a unique transaction identifier. In cases in which multiple related JWTs are issued, the transaction identifier claim can be used to correlate these related JWTs. Note that this claim can be used in JWTs that are SETs and also in JWTs using non-SET profiles. A value that represents the date and time at which the event occurred. This value is a NumericDate (see Section 2 of ). By omitting this claim, the issuer indicates that they are not sharing an event time with the recipient. (Note that in some use cases, the represented time might be approximate; statements about the accuracy of this field MAY be made by profiling specifications.) This claim is OPTIONAL.

This specification registers the application/secevent+jwt media type, which can be used to indicate that the content is a SET. SETs MAY include this media type in the typ header parameter of the JWT representing the SET to explicitly declare that the JWT is a SET. This MUST be included if the SET could be used in an application context in which it could be confused with other kinds of JWTs. Per the definition of typ in Section 4.1.9 of , it is RECOMMENDED that the "application/" prefix be omitted. Therefore, the typ value used SHOULD be secevent+jwt.

This section describes how to construct a SET.

The following is an example JWT Claims Set for a hypothetical SCIM SET (which has been formatted for readability): { "iss": "https://scim.example.com", "iat": 1458496404, "jti": "4d3559ec67504aaba65d40b0363faad8", "aud": [ "https://scim.example.com/Feeds/98d52461fa5bbc879593b7754", "https://scim.example.com/Feeds/5d7604516b1d08641d7676ee7" ], "events": { "urn:ietf:params:scim:event:create": { "ref": "https://scim.example.com/Users/44f6142df96bd6ab61e7521d9", "attributes": ["id", "name", "userName", "password", "emails"] } } }

The JSON Claims Set is encoded per .

In this example, the SCIM SET claims are encoded in an unsecured JWT. The JOSE Header for this example is: {"typ":"secevent+jwt","alg":"none"}

Base64url encoding (see Section 2 of ) of the octets of the UTF-8 representation of the JOSE Header yields: eyJ0eXAiOiJzZWNldmVudCtqd3QiLCJhbGciOiJub25lIn0

The above example JWT Claims Set is encoded as follows: eyJqdGkiOiI0ZDM1NTllYzY3NTA0YWFiYTY1ZDQwYjAzNjNmYWFkOCIsImlhdCI6MTQ1 ODQ5NjQwNCwiaXNzIjoiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tIiwiYXVkIjpbImh0 dHBzOi8vc2NpbS5leGFtcGxlLmNvbS9GZWVkcy85OGQ1MjQ2MWZhNWJiYzg3OTU5M2I3 NzU0IiwiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tL0ZlZWRzLzVkNzYwNDUxNmIxZDA4 NjQxZDc2NzZlZTciXSwiZXZlbnRzIjp7InVybjppZXRmOnBhcmFtczpzY2ltOmV2ZW50 OmNyZWF0ZSI6eyJyZWYiOiJodHRwczovL3NjaW0uZXhhbXBsZS5jb20vVXNlcnMvNDRm NjE0MmRmOTZiZDZhYjYxZTc1MjFkOSIsImF0dHJpYnV0ZXMiOlsiaWQiLCJuYW1lIiwi dXNlck5hbWUiLCJwYXNzd29yZCIsImVtYWlscyJdfX19

The encoded JWS signature is the empty string. Concatenating the parts yields this complete SET: eyJ0eXAiOiJzZWNldmVudCtqd3QiLCJhbGciOiJub25lIn0. eyJqdGkiOiI0ZDM1NTllYzY3NTA0YWFiYTY1ZDQwYjAzNjNmYWFkOCIsImlhdCI6MTQ1 ODQ5NjQwNCwiaXNzIjoiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tIiwiYXVkIjpbImh0 dHBzOi8vc2NpbS5leGFtcGxlLmNvbS9GZWVkcy85OGQ1MjQ2MWZhNWJiYzg3OTU5M2I3 NzU0IiwiaHR0cHM6Ly9zY2ltLmV4YW1wbGUuY29tL0ZlZWRzLzVkNzYwNDUxNmIxZDA4 NjQxZDc2NzZlZTciXSwiZXZlbnRzIjp7InVybjppZXRmOnBhcmFtczpzY2ltOmV2ZW50 OmNyZWF0ZSI6eyJyZWYiOiJodHRwczovL3NjaW0uZXhhbXBsZS5jb20vVXNlcnMvNDRm NjE0MmRmOTZiZDZhYjYxZTc1MjFkOSIsImF0dHJpYnV0ZXMiOlsiaWQiLCJuYW1lIiwi dXNlck5hbWUiLCJwYXNzd29yZCIsImVtYWlscyJdfX19.

For the purpose of having a simpler example in , an unsecured token is shown. When SETs are not signed or encrypted, other mechanisms such as TLS MUST be employed to provide integrity protection, confidentiality, and issuer authenticity, as needed by the application. When validation (i.e., auditing), or additional transmission security is required, JWS signing and/or JWE encryption MAY be used. To create and or validate a signed and/or encrypted SET, follow the instructions in Section 7 of .

Profiling specifications of this specification define actual SETs to be used in particular use cases. These profiling specifications define the syntax and semantics of SETs conforming to that SET profile and rules for validating those SETs. Profiling specifications SHOULD define syntax, semantics, subject identification, and validation. The syntax of the SETs defined, including: Claims and values placed at the JWT Claims Set. Examples are claims defined by the JWT specification (see ), the SET specification, and by the profiling specification. The JSON data structure contents and format, containing event-specific information, if any (see ). Defining the semantics of the SET contents for SETs utilizing the profile is equally important. Possibly most important is defining the procedures used to validate the SET issuer and to obtain the keys controlled by the issuer that were used for cryptographic operations used in the JWT representing the SET. For instance, some profiles may define an algorithm for retrieving the SET issuer's keys that uses the iss claim value as its input. Likewise, if the profile allows (or requires) that the JWT be unsecured, the means by which the integrity of the JWT is ensured MUST be specified. Profiling specifications MUST define how the event subject is identified in the SET, as well as how to differentiate between the event subject's issuer and the SET issuer, if applicable. It is NOT RECOMMENDED for profiling specifications to use the sub claim in cases in which the subject is not globally unique and has a different issuer from the SET itself. Profiling specifications MUST clearly specify the steps that a recipient of a SET utilizing that profile MUST perform to validate that the SET is both syntactically and semantically valid. Among the syntax and semantics of SETs that a profiling specification may define is whether the value of the events claim may contain multiple members, and what processing instructions are employed in the single- and multiple-valued cases for SETs conforming to that profile. Many valid choices are possible. For instance, some profiles might allow multiple event identifiers to be present and specify that any that are not understood by recipients be ignored, thus enabling extensibility. Other profiles might allow multiple event identifiers to be present but require that all be understood if the SET is to be accepted. Some profiles might require that only a single value be present. All such choices are within the scope of profiling specifications to define.

Because states that "all claims that are not understood by implementations MUST be ignored", there is a consideration that a SET might be confused with another kind of JWT from the same issuer. Unless this confusion is prevented, this might enable an attacker who possesses a SET to use it in a context in which another kind of JWT is expected, or vice-versa. This section presents concrete techniques for preventing confusion between SETs and several other specific kinds of JWTs, as well as generic techniques for preventing possible confusion between SETs and other kinds of JWTs.

A SET might be confused with ID Token if a SET is mistakenly or maliciously used in a context requiring an ID Token. If a SET could otherwise be interpreted as a valid ID Token (because it includes the required claims for an ID Token and valid issuer and audience claim values for an ID Token) then that SET profile MUST require that the exp claim not be present in the SET. Because exp is a required claim in ID Tokens, valid ID Token implementations will reject such a SET if presented as if it were an ID Token. Excluding exp from SETs that could otherwise be confused with ID Tokens is actually defense in depth. In any OpenID Connect contexts in which an attacker could attempt to substitute a SET for an ID Token, the SET would actually already be rejected as an ID Token because it would not contain the correct nonce claim value for the ID Token to be accepted in contexts for which substitution is possible. Note that the use of explicit typing, as described in , will not achieve disambiguation between ID Tokens and SETs, as the ID Token validation rules do not use the typ header parameter value.

OAuth 2.0 defines access tokens as being opaque. Nonetheless, some implementations implement access tokens as JWTs. Because the structure of these JWTs is implementation-specific, ensuring that a SET cannot be confused with such an access token is therefore likewise, in general, implementation specific. Nonetheless, it is recommended that SET profiles employ the following strategies to prevent possible substitutions of SETs for access tokens in contexts in which that might be possible: Prohibit use of the exp claim, as is done to prevent ID Token confusion. Where possible, use a separate aud claim value to distinguish between the SET recipient and the protected resource that is the audience of an access token. Modify access token validation systems to check for the presence of the events claim as a means to detect security event tokens. This is particularly useful if the same endpoint may receive both types of tokens. Employ explicit typing, as described in , and modify access token validation systems to use the typ header parameter value.

JWTs are now being used in application areas beyond the identity applications in which they first appeared. For instance, the "Session Initiation Protocol (SIP) Via Header Field Parameter to Indicate Received Realm" and "Personal Assertion Token (PASSporT)" specifications both define JWT profiles that use mostly or completely different sets of claims than are used by ID Tokens. If it would otherwise be possible for an attacker to substitute a SET for one of these (or other) kinds of JWTs, then the SET profile must be defined in such a way that any substituted SET will result in its rejection when validated as the intended kind of JWT. The most direct way to prevent confusion is to employ explicit typing, as described in , and modify applicable token validation systems to use the typ header parameter value. This approach can be employed for new systems but may not be applicable to existing systems. Another way to ensure that a SET is not confused with another kind of JWT is to have the JWT validation logic reject JWTs containing an events claim unless the JWT is intended to be a SET. This approach can be employed for new systems but may not be applicable to existing systems. Validating that the JWT has an events claim will be effective in preventing attackers from passing other kinds of JWTs off as SETs. For many use cases, the simplest way to prevent substitution is requiring that the SET not include claims that are required for the kind of JWT that might be the target of an attack. For example, for , the sip_callid claim could be omitted and for , the orig claim could be omitted. In many contexts, simple measures such as these will accomplish the task, should confusion otherwise even be possible. Note that this topic is being explored in a more general fashion in JSON Web Token Best Current Practices . The proposed best practices in that draft may also be applicable for particular SET profiles and use cases.

SETs may contain sensitive information. Therefore, methods for distribution of events SHOULD require the use of a transport-layer security mechanism when distributing events. Parties MUST support TLS 1.2 or a higher version and MAY support additional transport-layer mechanisms meeting its security requirements. When using TLS, the client MUST perform a TLS server certificate check, per . Implementation security considerations for TLS can be found in "Recommendations for Secure Use of TLS and DTLS" . Security events distributed through third parties or that carry personally identifiable information MUST be encrypted using JWE or secured for confidentiality by other means. Unless integrity of the JWT is ensured by other means, it MUST be signed using JWS by an issuer that is trusted to do so for the use case so that the SET can be authenticated and validated by the SET recipient.

This specification does not define a delivery mechanism for SETs. In addition to confidentiality and integrity (discussed above), implementers and profiling specifications must consider the consequences of delivery mechanisms that are not secure and/or not assured. For example, while a SET may be end-to-end secured using JWE encrypted SETs, without (mutual) TLS, there is no assurance that the correct endpoint received the SET and that it could be successfully processed.

This specification defines no means of ordering multiple SETs in a sequence. Depending on the type and nature of the events represented by SETs, order may or may not matter. For example, in provisioning, event order is critical -- an object cannot be modified before it is created. In other SET types, such as a token revocation, the order of SETs for revoked tokens does not matter. If, however, the event conveys a logged in or logged out status for a user subject, then order becomes important. Profiling specifications and implementers SHOULD take caution when using timestamps such as iat to define order. Distributed systems will have some amount of clock skew. Thus, time by itself will not guarantee order. Specifications profiling SET SHOULD define a mechanism for detecting order or sequence of events when the order matters. For example, the txn claim could contain an ordered value (e.g., a counter) that the issuer includes, although just as for timestamps, ensuring such ordering can be difficult in distributed systems.

When SETs are delivered asynchronously and/or out-of-band with respect to the original action that incurred the security event, it is important to consider that a SET might be delivered to a SET recipient in advance of or behind the process that caused the event. For example, a user having been required to log out and then log back in again, may cause a "token revoked" SET to be issued, typically causing the receiver to reset all active sessions at the receiver that are related to that user. If revocation SET arrives at the same time as the user agent re-logs in, timing could cause problems by erroneously treating the new user session as logged out. Profiling specifications SHOULD be careful to consider both SET expression and timing issues. For example, it might be more appropriate to revoke a specific session or identity token rather than a general logout statement about a "user". Alternatively, profiling specifications could use timestamps that allow new sessions to be started immediately after a stated logout event time.

Also, see above for both additional security considerations and normative text on preventing SETs from being confused with other kinds of JWTs.

If a SET needs to be retained for audit purposes, the signature can be used to provide verification of its authenticity. SET issuers SHOULD attempt to specialize SETs so that their content is targeted to the specific business and protocol needs of the intended SET recipients. When sharing personally identifiable information or information that is otherwise considered confidential to affected users, SET issuers and recipients should have the appropriate legal agreements and user consent and/or terms of service in place. The propagation of subject identifiers can be perceived as personally identifiable information. Where possible, SET issuers and recipients SHOULD devise approaches that prevent propagation -- for example, the passing of a salted hash value that requires the SET recipient to know the subject. In some cases, it may be possible for a SET recipient to correlate different events and thereby gain information about a subject that the SET issuer did not intend to share. For example, a SET recipient might be able to use iat values or highly precise toe values to determine that two otherwise un-relatable events actually relate to the same real-world event. The union of information from both events could allow a SET recipient to de-anonymize data or recognize that unrelated identifiers relate to the same individual. SET issuers SHOULD take steps to minimize the chance of event correlation, when such correlation would constitute a privacy violation. For instance, they could use approximate values for the toe claim or arbitrarily delay SET issuance, where such delay can be tolerated.

This specification registers the events, toe, and txn claims in the IANA "JSON Web Token Claims" registry established by .

Claim Name: events Claim Description: Security Events Change Controller: IESG Specification Document(s): of [[ this specification ]] Claim Name: toe Claim Description: Time of Event Change Controller: IESG Specification Document(s): of [[ this specification ]] Claim Name: txn Claim Description: Transaction Identifier Change Controller: IESG Specification Document(s): of [[ this specification ]]

This section registers the +jwt structured syntax suffix in the "Structured Syntax Suffix" registry in the manner described in , which can be used to indicate that the media type is encoded as a JWT.

Name: JSON Web Token (JWT) +suffix: +jwt References: Section 3 of Encoding considerations: binary; JWT values are encoded as a series of base64url-encoded values (some of which may be the empty string) separated by period ('.') characters. Interoperability considerations: n/a Fragment identifier considerations: The syntax and semantics of fragment identifiers specified for +jwt SHOULD be as specified for "application/jwt". (At publication of this document, there is no fragment identification syntax defined for "application/jwt".) The syntax and semantics for fragment identifiers for a specific "xxx/yyy+jwt" SHOULD be processed as follows: For cases defined in +jwt, where the fragment identifier resolves per the +jwt rules, then process as specified in +jwt. For cases defined in +jwt, where the fragment identifier does not resolve per the +jwt rules, then process as specified in "xxx/yyy+jwt". For cases not defined in +jwt, then process as specified in "xxx/yyy+jwt". Security considerations: See Section 11 of . Contact: Michael B. Jones, mbj@microsoft.com Author/Change controller: Security Events Working Group. The IESG has change control over this registration.

This section registers the application/secevent+jwt media type in the "Media Types" registry in the manner described in , which can be used to indicate that the content is a SET. Type name: application Subtype name: secevent+jwt Required parameters: n/a Optional parameters: n/a Encoding considerations: binary; A SET is a JWT; JWT values are encoded as a series of base64url-encoded values (some of which may be the empty string) separated by period ('.') characters. Security considerations: See of [[ this specification ]] Interoperability considerations: n/a Published specification: of [[ this specification ]] Applications that use this media type: Applications that exchange SETs Fragment identifier considerations: n/a Additional information: Magic number(s): n/a File extension(s): n/a Macintosh file type code(s): n/a Person & email address to contact for further information: Michael B. Jones, mbj@microsoft.com Intended usage: COMMON Restrictions on usage: none Author: Michael B. Jones, mbj@microsoft.com Change controller: IESG Provisional registration? No

IANA IANA IANA Nomura Research Institute, Ltd. Ping Identity Microsoft Google Salesforce Microsoft Ping Identity OpenID Foundation

The editors would like to thank the members of the IETF SCIM working group, which began discussions of provisioning events starting with draft-hunt-scim-notify-00 in 2015. The editors would like to thank the participants in the IETF id-event mailing list, the Security Events working group, and related working groups for their contributions to this specification. The specification incorporates suggestions made by many people, including Annabelle Backman, John Bradley, Alissa Cooper, Ned Freed, Dick Hardt, Russ Housley, Benjamin Kaduk, Mark Lizar, Alexey Melnikov, Andrew Nash, Eric Rescorla, Adam Roach, Justin Richer, Nat Sakimura, Marius Scurtescu, and Yaron Sheffer.

[[ to be removed by the RFC Editor before publication as an RFC ]] From the original draft-hunt-idevent-token: Draft 01 - PH - Renamed eventUris to events Draft 00 - PH - First Draft Draft 01 - PH - Fixed some alignment issues with JWT. Remove event type attribute. Draft 02 - PH - Renamed to Security Events, removed questions, clarified examples and intro text, and added security and privacy section. Draft 03 - PH General edit corrections from Sarah Squire Changed "event" term to "SET" Corrected author organization for William Denniss to Google Changed definition of SET to be 2 parts, an envelope and 1 or more payloads. Clarified that the intent is to express a single event with optional extensions only. - mbj - Registered events claim, and proof-reading corrections. Draft 04 - PH - Re-added the "sub" claim with clarifications that any SET type may use it. Added additional clarification on the use of envelope vs. payload attributes Added security consideration for event timing. Switched use of "attribute" to "claim" for consistency. Revised examples to put "sub" claim back in the top level. Added clarification that SETs typically do not use "exp". Added security consideration for distinguishing Access Tokens and SETs. Draft 05 - PH - Fixed find/replace error that resulted in claim being spelled claimc Draft 06 - PH - Corrected typos New txn claim New security considerations Sequencing and Timing Issues Draft 07 - PH - Moved payload objects to be values of event URI attributes, per discussion. mbj - Applied terminology consistency and grammar cleanups. Draft 08 - PH - Added clarification to status of examples Changed from primary vs. extension to state that multiple events may be expressed, some of which may or may not be considered extensions of others (which is for the subscriber or profiling specifications to determine). Other editorial changes suggested by Yaron From draft-ietf-secevent-token: Draft 00 - PH - First WG Draft based on draft-hunt-idevent-token Draft 01 - PH - Changes as follows: Changed terminology away from pub-sub to transmitter/receiver based on WG feedback Cleaned up/removed some text about extensions (now only used as example) Clarify purpose of spec vs. future profiling specs that define actual events Draft 02 - Changes are as follows: mbj - Added the Requirements for SET Profiles section. mbj - Expanded the Security Considerations section to describe how to prevent confusion of SETs with ID Tokens, access tokens, and other kinds of JWTs. mbj - Registered the application/secevent+jwt media type and defined how to use it for explicit typing of SETs. mbj - Clarified the misleading statement that used to say that a SET conveys a single security event. mbj - Added a note explicitly acknowledging that some SET profiles may choose to convey event subject information in the event payload. PH - Corrected encoded claim example on page 10. mbj - Applied grammar corrections. Draft 03 - Changes are as follows: pjh - Corrected old "subscriber" to "Event Receiver". Added clarification in definition that Event Receiver is the same as JWT recipient. pjh - Added definition for "toe" (and IANA registration). pjh - Removed "nbf" claim. pjh - Figure 3, moved "sub" to the events payload next to "iss". pjh - Clarified the use of "nonce" in contexts where substitution is possible. mbj - Addressed WGLC comments by Nat Sakimura. mbj - Addressed WGLC comments by Annabelle Backman. mbj - Addressed WGLC comments by Marius Scurtescu. Draft 04 - mbj - Changes were as follows: Clarified that all "events" values must represent aspects of the same state change that occurred to the subject -- not an aggregation of unrelated events about the subject. Removed ambiguities about the roles of multiple "events" values and the responsibilities of profiling specifications for defining how and when they are used. Corrected places where the term JWT was used when what was actually being discussed was the JWT Claims Set. Addressed terminology inconsistencies. In particular, standardized on using the term "issuer" to align with JWT terminology and the "iss" claim. Previously the term "transmitter" was sometimes used and "issuer" was sometimes used. Likewise, standardized on using the term "recipient" instead of "receiver" for the same reasons. Added a RISC event example, courtesy of Marius Scurtescu. Applied wording clarifications suggested by Annabelle Backman and Yaron Sheffer. Applied numerous grammar, syntax, and formatting corrections. Draft 05 - mbj - Changes were as follows: Simplified the definitions of the "iat" and "toe" claims in ways suggested by Annabelle Backman. Added privacy considerations text suggested by Annabelle Backman. Updated the RISC event example, courtesy of Marius Scurtescu. Reordered the claim definitions to place the required claims first. Changed to using the RFC 8174 boilerplate instead of the RFC 2119 boilerplate. Draft 06 - mbj - Changes were as follows: Changed "when the event was issued" to "when the SET was issued" in the "iat" description, as suggested by Annabelle Backman. Applied editorial improvements that improve the consistency of the specification that were suggested by Annabelle Backman, Marius Scurtescu, and Yaron Sheffer. Draft 07 - PH - Text refinement to Section 3 proposed by Annabelle Backman post WGLC Draft 08 - mbj - Changes were as follows: Incorporated wording improvements resulting from Russ Housley's SecDir comments. Acknowledged individuals who made significant contributions. Draft 09 - pjh/mbj - Changes addressing AD review comments by Benjamin Kaduk Draft 10 - pjh/mbj - Changes were as follows: Incorporated wording improvements resulting from Russ Housley's additional SecDir comments. Registered +jwt structured syntax suffix. Draft 11 - pjh/mbj - Incorporated feedback from Security Area Director Eric Rescorla and IANA Designated Expert Ned Freed. Clarified "iss" claim language about the SET issuer versus the security subject issuer. Changed a "SHOULD" to a "MUST" in the "sub" claim description to be consistent with the Requirements for SET Profiles section. Described the use of the "events" claim to prevent attackers from passing off other kinds of JWTs as SETs. Stated that SETs are to be signed by an issuer that is trusted to do so for the use case. Added quotes in the phrase '"token revoked" SET to be issued' in the Timing Issues section. Added section number references to the media type and media type suffix registrations. Changed the encodings of the media type and media type suffix registrations to binary (since no line breaks are allowed). Replaced a "TBD" in the media type registration with descriptive text. Acknowledged Eric Rescorla and Ned Freed. Draft 12 - pjh/mbj - Incorporated feedback from Adam Roach, Alexey Melnikov, and Alissa Cooper. Removed unused references to RFC 7009 and RFC 7517. Corrected name of RFC 8055 in Section 4.3 to "Session Initiation Protocol (SIP) Via Header Field Parameter to Indicate Received Realm". Added normative references for base64url and UTF-8. Section 5.1 - Changed SHOULD to MUST in "personally identifiable information MUST be encrypted using JWE [RFC7516] or ...". Section 5.2 - Changed "MUST consider" to "must consider".