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use std::fmt;
use quickcheck::{Arbitrary, Gen};
/// The OpenPGP packet tags as defined in [Section 4.3 of RFC 4880].
///
/// [Section 4.3 of RFC 4880]: https://tools.ietf.org/html/rfc4880#section-4.3
///
/// The values correspond to the serialized format.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum Tag {
/// Reserved Packet tag.
Reserved,
/// Public-Key Encrypted Session Key Packet.
PKESK,
/// Signature Packet.
Signature,
/// Symmetric-Key Encrypted Session Key Packet.
SKESK,
/// One-Pass Signature Packet.
OnePassSig,
/// Secret-Key Packet.
SecretKey,
/// Public-Key Packet.
PublicKey,
/// Secret-Subkey Packet.
SecretSubkey,
/// Compressed Data Packet.
CompressedData,
/// Symmetrically Encrypted Data Packet.
SED,
/// Marker Packet (Obsolete Literal Packet).
Marker,
/// Literal Data Packet.
Literal,
/// Trust Packet.
Trust,
/// User ID Packet.
UserID,
/// Public-Subkey Packet.
PublicSubkey,
/// User Attribute Packet.
UserAttribute,
/// Sym. Encrypted and Integrity Protected Data Packet.
SEIP,
/// Modification Detection Code Packet.
MDC,
/// AEAD Encrypted Data Packet.
AED,
/// Unassigned packets (as of RFC4880).
Unknown(u8),
/// Experimental packets.
Private(u8),
}
impl From<u8> for Tag {
fn from(u: u8) -> Self {
use packet::Tag::*;
match u {
0 => Reserved,
1 => PKESK,
2 => Signature,
3 => SKESK,
4 => OnePassSig,
5 => SecretKey,
6 => PublicKey,
7 => SecretSubkey,
8 => CompressedData,
9 => SED,
10 => Marker,
11 => Literal,
12 => Trust,
13 => UserID,
14 => PublicSubkey,
17 => UserAttribute,
18 => SEIP,
19 => MDC,
20 => AED,
60...63 => Private(u),
_ => Unknown(u),
}
}
}
impl From<Tag> for u8 {
fn from(t: Tag) -> u8 {
match t {
Tag::Reserved => 0,
Tag::PKESK => 1,
Tag::Signature => 2,
Tag::SKESK => 3,
Tag::OnePassSig => 4,
Tag::SecretKey => 5,
Tag::PublicKey => 6,
Tag::SecretSubkey => 7,
Tag::CompressedData => 8,
Tag::SED => 9,
Tag::Marker => 10,
Tag::Literal => 11,
Tag::Trust => 12,
Tag::UserID => 13,
Tag::PublicSubkey => 14,
Tag::UserAttribute => 17,
Tag::SEIP => 18,
Tag::MDC => 19,
Tag::AED => 20,
Tag::Private(x) => x,
Tag::Unknown(x) => x,
}
}
}
impl fmt::Display for Tag {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
Tag::Reserved =>
f.write_str("Reserved - a packet tag MUST NOT have this value"),
Tag::PKESK =>
f.write_str("Public-Key Encrypted Session Key Packet"),
Tag::Signature =>
f.write_str("Signature Packet"),
Tag::SKESK =>
f.write_str("Symmetric-Key Encrypted Session Key Packet"),
Tag::OnePassSig =>
f.write_str("One-Pass Signature Packet"),
Tag::SecretKey =>
f.write_str("Secret-Key Packet"),
Tag::PublicKey =>
f.write_str("Public-Key Packet"),
Tag::SecretSubkey =>
f.write_str("Secret-Subkey Packet"),
Tag::CompressedData =>
f.write_str("Compressed Data Packet"),
Tag::SED =>
f.write_str("Symmetrically Encrypted Data Packet"),
Tag::Marker =>
f.write_str("Marker Packet"),
Tag::Literal =>
f.write_str("Literal Data Packet"),
Tag::Trust =>
f.write_str("Trust Packet"),
Tag::UserID =>
f.write_str("User ID Packet"),
Tag::PublicSubkey =>
f.write_str("Public-Subkey Packet"),
Tag::UserAttribute =>
f.write_str("User Attribute Packet"),
Tag::SEIP =>
f.write_str("Sym. Encrypted and Integrity Protected Data Packet"),
Tag::MDC =>
f.write_str("Modification Detection Code Packet"),
Tag::AED =>
f.write_str("AEAD Encrypted Data Packet"),
Tag::Private(u) =>
f.write_fmt(format_args!("Private/Experimental Packet {}", u)),
Tag::Unknown(u) =>
f.write_fmt(format_args!("Unknown Packet {}", u)),
}
}
}
impl Arbitrary for Tag {
fn arbitrary<G: Gen>(g: &mut G) -> Self {
u8::arbitrary(g).into()
}
}
impl Tag {
/// Returns whether the `Tag` can be at the start of a valid
/// message.
///
/// [TPKs] can start with `PublicKey`, [TSKs] with a `SecretKey`.
///
/// [TPKs]: https://tools.ietf.org/html/rfc4880#section-11.1
/// [TSKs]: https://tools.ietf.org/html/rfc4880#section-11.2
///
/// [Messages] start with a `OnePassSig`, `Signature` (old style
/// non-one pass signatures), `PKESK`, `SKESK`, `CompressedData`,
/// or `Literal`.
///
/// [Messages]: https://tools.ietf.org/html/rfc4880#section-11.3
///
/// Signatures can standalone either as a [detached signature], a
/// third-party certification, or a revocation certificate.
///
/// [detached signature]: https://tools.ietf.org/html/rfc4880#section-11.3
pub fn valid_start_of_message(&self) -> bool {
// TPK
*self == Tag::PublicKey || *self == Tag::SecretKey
// Message.
|| *self == Tag::PKESK || *self == Tag::SKESK
|| *self == Tag::Literal || *self == Tag::CompressedData
// Signed message.
|| *self == Tag::OnePassSig
// Standalone signature, old-style signature.
|| *self == Tag::Signature
}
}
#[cfg(test)]
mod tests {
use super::*;
quickcheck! {
fn roundtrip(tag: Tag) -> bool {
let val: u8 = tag.into();
tag == Tag::from(val)
}
}
quickcheck! {
fn display(tag: Tag) -> bool {
let s = format!("{}", tag);
!s.is_empty()
}
}
quickcheck! {
fn unknown_private(tag: Tag) -> bool {
match tag {
Tag::Unknown(u) => u > 19 || u == 15 || u == 16,
Tag::Private(u) => u >= 60 && u <= 63,
_ => true
}
}
}
#[test]
fn parse() {
for i in 0..0x100usize {
Tag::from(i as u8);
}
}
}