Differences

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--- dkim_support [2016/05/18 15:18] – lucy
+++ dkim_support [2016/05/18 15:21] – [Setup DKIM in LUCY] lucy
@@ Line 32: / Line 32: @@
 **Note**: Lucy sends out DKIM-signed emails with "mail.domainkey_" part built-in and before LUCY 3.2 there is no configuration option to change that. Same for the DKIM header, which is fixed.
+===== DKIM Header Explanation=====
+Here is an example DKIM signature (recorded as an RFC2822 header field) for the signed message:
+ DKIM-Signature a=rsa-sha1; q=dns;
+ d=example.com;
+ i=user@eng.example.com;
+ s=jun2005.eng; c=relaxed/simple;
+ t=1117574938; x=1118006938;
+ h=from:to:subject:date;
+ b=dzdVyOfAKCdLXdJOc9G2q8LoXSlEniSb
+ av+yuU4zGeeruD00lszZVoG4ZHRNiYzR
+Let's take this piece by piece to see what it means. Each "tag" is associated with a value.
+  * b = the actual digital signature of the contents (headers and body) of the mail message
+  * bh = the body hash
+  * d = the signing domain
+  * s = the selector
+  * v = the version
+  * a = the signing algorithm
+  * c = the canonicalization algorithm(s) for header and body
+  * q = the default query method
+  * l = the length of the canonicalized part of the body that has been signed
+  * t = the signature timestamp
+  * x = the expire time
+  * h = the list of signed header fields, repeated for fields that occur multiple times
+We can see from this email that:
+  * The digital signature is dzdVyOfAKCdLXdJOc9G2q8LoXSlEniSbav+yuU4zGeeruD00lszZVoG4ZHRNiYzR. This signature is matched with the one stored at the sender's domain.
+  * The body hash is not listed.
+  * The signing domain is example.com.This is the domain that sent (and signed) the message.
+  * The selector is jun2005.eng.
+  * The version is not listed.
+  * The signing algorithm is rsa-sha1. This is the algorith used to generate the signature.
+  * The canonicalization algorithm(s) for header and body are relaxed/simple.
+  * The default query method is DNS. This is the method used to look up the key on the signing domain.
+  * The length of the canonicalized part of the body that has been signed is not listed. The signing domain can generate a key based on the entire body or only some portion of it. That portion would be listed here.
+  * The signature timestamp is 1117574938. This is when it was signed.
+  * The expire time is 1118006938. Because an already signed email can be reused to "fake" the signature, signatures are set to expire.
+  * The list of signed header fields includes from:to:subject:date. This is the list of fields that have been "signed" to verify that they have not been modified.