RFC 1847 (rfc1847) - Page 3 of 11
Security Multiparts for MIME: Multipart/Signed and Multipart/Encrypted
Alternative Format: Original Text Document
RFC 1847 Security Multiparts October 1995 2.1. Definition of Multipart/Signed (1) MIME type name: multipart (2) MIME subtype name: signed (3) Required parameters: boundary, protocol, and micalg (4) Optional parameters: none (5) Security considerations: Must be treated as opaque while in transit The multipart/signed content type contains exactly two body parts. The first body part is the body part over which the digital signature was created, including its MIME headers. The second body part contains the control information necessary to verify the digital signature. The first body part may contain any valid MIME content type, labeled accordingly. The second body part is labeled according to the value of the protocol parameter. The attribute token for the protocol parameter is "protocol", i.e., parameter := "protocol" "=" value The value token is comprised of the type and sub-type tokens of the Content-Type: header of the second body part, i.e., value := <"> type "/" subtype <"> where the type and subtype tokens are defined by the MIME [2] specification. The semantics of the protocol parameter are defined according to its value. The attribute token for the micalg parameter is "micalg", i.e., parameter := "micalg" "=" value The Message Integrity Check (MIC) is the name given to the quantity computed over the body part with a message digest or hash function, in support of the digital signature service. Valid value tokens are defined by the specification for the value of the protocol parameter. The value may be a comma (",") separated list of tokens, indicating the use of multiple MIC algorithms. As a result, the comma (",") character is explicitly excluded from the list of characters that may be included in a token used as a value of the micalg parameter. If multiple MIC algorithms are specified, the purpose and use of the multiple algorithms is defined by the protocol. If the MIC algorithm Galvin, et al Standards Track
