1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148
use std::hash::{Hash, Hasher};
use std::cmp::Ordering;
use crate::packet::Tag;
use crate::packet;
use crate::Packet;
use crate::policy::HashAlgoSecurity;
/// Holds an unknown packet.
///
/// This is used by the parser to hold packets that it doesn't know
/// how to process rather than abort.
///
/// This packet effectively holds a binary blob.
///
/// # A note on equality
///
/// Two `Unknown` packets are considered equal if their tags and their
/// bodies are equal.
#[derive(Debug)]
pub struct Unknown {
/// CTB packet header fields.
pub(crate) common: packet::Common,
/// Packet tag.
tag: Tag,
/// Error that caused parsing or processing to abort.
error: anyhow::Error,
/// The unknown data packet is a container packet, but cannot
/// store packets.
///
/// This is written when serialized, and set by the packet parser
/// if `buffer_unread_content` is used.
container: packet::Container,
}
assert_send_and_sync!(Unknown);
impl PartialEq for Unknown {
fn eq(&self, other: &Unknown) -> bool {
self.tag == other.tag
&& self.container == other.container
}
}
impl Eq for Unknown { }
impl Hash for Unknown {
fn hash<H: Hasher>(&self, state: &mut H) {
self.tag.hash(state);
self.container.hash(state);
}
}
impl Clone for Unknown {
fn clone(&self) -> Self {
Unknown {
common: self.common.clone(),
tag: self.tag,
error: anyhow::anyhow!("{}", self.error),
container: self.container.clone(),
}
}
}
impl Unknown {
/// Returns a new `Unknown` packet.
pub fn new(tag: Tag, error: anyhow::Error) -> Self {
Unknown {
common: Default::default(),
tag,
error,
container: packet::Container::default_unprocessed(),
}
}
/// The security requirements of the hash algorithm for
/// self-signatures.
///
/// A cryptographic hash algorithm usually has [three security
/// properties]: pre-image resistance, second pre-image
/// resistance, and collision resistance. If an attacker can
/// influence the signed data, then the hash algorithm needs to
/// have both second pre-image resistance, and collision
/// resistance. If not, second pre-image resistance is
/// sufficient.
///
/// [three security properties]: https://en.wikipedia.org/wiki/Cryptographic_hash_function#Properties
///
/// In general, an attacker may be able to influence third-party
/// signatures. But direct key signatures, and binding signatures
/// are only over data fully determined by signer. And, an
/// attacker's control over self signatures over User IDs is
/// limited due to their structure.
///
/// These observations can be used to extend the life of a hash
/// algorithm after its collision resistance has been partially
/// compromised, but not completely broken. For more details,
/// please refer to the documentation for [HashAlgoSecurity].
///
/// [HashAlgoSecurity]: crate::policy::HashAlgoSecurity
pub fn hash_algo_security(&self) -> HashAlgoSecurity {
HashAlgoSecurity::CollisionResistance
}
/// Gets the unknown packet's tag.
pub fn tag(&self) -> Tag {
self.tag
}
/// Sets the unknown packet's tag.
pub fn set_tag(&mut self, tag: Tag) -> Tag {
::std::mem::replace(&mut self.tag, tag)
}
/// Gets the unknown packet's error.
///
/// This is the error that caused parsing or processing to abort.
pub fn error(&self) -> &anyhow::Error {
&self.error
}
/// Sets the unknown packet's error.
///
/// This is the error that caused parsing or processing to abort.
pub fn set_error(&mut self, error: anyhow::Error) -> anyhow::Error {
::std::mem::replace(&mut self.error, error)
}
/// Best effort Ord implementation.
///
/// The Cert canonicalization needs to order Unknown packets.
/// However, due to potential streaming, Unknown cannot implement
/// Eq. This is cheating a little, we simply ignore the streaming
/// case.
pub(crate) // For cert/mod.rs
fn best_effort_cmp(&self, other: &Unknown) -> Ordering {
self.tag.cmp(&other.tag).then_with(|| self.body().cmp(other.body()))
}
}
impl_body_forwards!(Unknown);
impl From<Unknown> for Packet {
fn from(s: Unknown) -> Self {
Packet::Unknown(s)
}
}