From 86f0af337b3d4c8afc075c09a1aae4b1694d9ebd Mon Sep 17 00:00:00 2001 From: Arun Isaac Date: Sun, 24 Oct 2021 02:46:01 +0530 Subject: email: Handle unrecognized Content-Transfer-Encoding headers. * email/email.scm (handle-invalid-headers): New function. (parse-email-headers): Handle invalid headers. * tests/email.scm ("Assume application/octet-stream Content-Type if Content-Transfer-Encoding is unrecognized"): New test. --- email/email.scm | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'email') diff --git a/email/email.scm b/email/email.scm index 277be88..7aea2d3 100644 --- a/email/email.scm +++ b/email/email.scm @@ -972,6 +972,19 @@ message. Else, return a single record." 'content-transfer-encoding '#{7bit}#) headers)) +(define (handle-invalid-headers headers) + ;; ยง6.4 of RFC2045 specifies that any entity with an unrecognized + ;; Content-Transfer-Encoding must be treated as if it has a + ;; Content-Type of "application/octet-stream", regardless of what + ;; the Content-Type header field actually says. + (if (memq (assq-ref headers 'content-transfer-encoding) + (list '7bit '8bit 'binary 'quoted-printable 'base64)) + headers + (alist-combine headers + '((content-type (type . application) + (subtype . octet-stream)) + (content-transfer-encoding . binary))))) + (define (add-default-mime-entity-headers parent-headers headers) ;; Default Content-Type and Content-Transfer-Encoding headers as ;; specified in RFC2045 and RFC2046 @@ -1088,7 +1101,8 @@ list of header keys and values." (keywords . ,(lambda (_ value) (cons 'keywords (string-split value #\,)))) (fields . ,(lambda (_ . fields) - (add-default-headers (post-process-fields fields)))) + (handle-invalid-headers + (add-default-headers (post-process-fields fields))))) (*text* . ,(lambda (_ value) value)) (*default* . ,(lambda tree tree))))) -- cgit v1.2.3