rules:
  - id: hmac-needs-new
    patterns:
        - pattern-either:
                - pattern: | 
                        $H := $HASH.New()
                        ...
                        $FUNC := func() hash.Hash { return $H }
                        ...
                        hmac.New($FUNC, ...)
                - pattern: | 
                        $H := $HASH.New()
                        ...
                        hmac.New(func() hash.Hash { return $H }, ...)

                - pattern: |
                        hmac.New(func() hash.Hash { return ( $H : hash.Hash) }, ...)

    message: "calling hmac.New with unchanging hash.New"
    languages: [go]
    severity: ERROR