DomainKeys Identified Mail (DKIM)


Install via npm

``sh
$ npm install --save dkim
`

References

- RFC 6368 - DomainKeys Identified Mail (DKIM) Signatures
- RFC 8301 - Cryptographic Algorithm and Key Usage Update to DomainKeys Identified Mail (DKIM)
- RFC 8463 - A New Cryptographic Signature Method for DomainKeys Identified Mail (DKIM)
- RFC 8616 - Email Authentication for Internationalized Mail
- RFC 7489 - Domain-based Message Authentication, Reporting, and Conformance (DMARC)

API

$3

Kind: global variable

* DKIM : Object
* .Signature
* new DKIM.Signature()
* .Key
* new DKIM.Key()
* .NONE : String
* .OK : String
* .TEMPFAIL : String
* .PERMFAIL : String
* [.getKey(domain, [selector], callback)](#DKIM.getKey)
* .processBody(message, method) ⇒ String
* .processHeader(headers, signHeaders, method) ⇒ String
* .verifySignature(body, headers, callback)
* .verify(message, callback)
* .filterSignatureHeaders(headers, signatureHeader) ⇒ Array.<String>

*

#### DKIM.Signature
Kind: static class of DKIM
See: dkim-signature

*

##### new DKIM.Signature()
DKIM Signature

*

#### DKIM.Key
Kind: static class of DKIM
See: dkim-key

*

##### new DKIM.Key()
DKIM Key

*

#### DKIM.NONE : String
Kind: static property of DKIM

*

#### DKIM.OK : String
Kind: static property of DKIM

*

#### DKIM.TEMPFAIL : String
Kind: static property of DKIM

*

#### DKIM.PERMFAIL : String
Kind: static property of DKIM

*

#### DKIM.getKey(domain, [selector], callback)
Retrieve a domain key

Kind: static method of DKIM
Todo

- [ ] DNS seems to FORMERR on unregistered / expired domains,
which maybe should be a TEMPFAIL (?)
- [ ] make this public_key = dkim_find_key(q_val, d_val, s_val),
where *_val are the signature's attribute values
- [ ] Throw error if the public key is not a Buffer

Params

- domain String
- [selector] String
- callback function


*

#### DKIM.processBody(message, method) ⇒ String
Canonicalize the message body according to
methods defined in RFC[XXXX]

Kind: static method of DKIM
Throws:

- Error If canonicalization method is unsupported

Params

- message Buffer | String
- method String - (simple|relaxed)


*

#### DKIM.processHeader(headers, signHeaders, method) ⇒ String
Canonicalize the message header according to
methods defined in RFC[6376]

Kind: static method of DKIM
Throws:

- Error If canonicalization method is unsupported

Params

- headers Array.<String> - Each header is formatted as :
- signHeaders Array
- method String - (simple|relaxed)

Example
`js
DKIM.processHeader( [ 'A: X', 'B : Y\t\r\n\tZ '], [ 'A' ], 'relaxed' )
`

*

#### DKIM.verifySignature(body, headers, callback)
Verify a message signature

Kind: static method of DKIM
Params

- body Buffer
- headers Array
- callback function


*

#### DKIM.verify(message, callback)
Verify a message's signatures

Kind: static method of DKIM
Throws:

- Error If input is not a buffer

Params

- message Buffer
- callback function


*

##### verify.filterSignatureHeaders(headers, signatureHeader) ⇒ Array.<String>
Filter out signature headers other than the specified signatureHeader`

Kind: static method of verify
Returns: Array.<String> - filtered headers
Params

- headers Array.<String> - list of headers to filter
- signatureHeader String - signature header to keep

*