ed25519_dalek/
errors.rs

1// -*- mode: rust; -*-
2//
3// This file is part of ed25519-dalek.
4// Copyright (c) 2017-2019 isis lovecruft
5// See LICENSE for licensing information.
6//
7// Authors:
8// - isis agora lovecruft <isis@patternsinthevoid.net>
9
10//! Errors which may occur when parsing keys and/or signatures to or from wire formats.
11
12// rustc seems to think the typenames in match statements (e.g. in
13// Display) should be snake cased, for some reason.
14#![allow(non_snake_case)]
15
16use core::error::Error;
17use core::fmt;
18use core::fmt::Display;
19
20/// Internal errors.  Most application-level developers will likely not
21/// need to pay any attention to these.
22#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
23pub(crate) enum InternalError {
24    PointDecompression,
25    ScalarFormat,
26    /// An error in the length of bytes handed to a constructor.
27    ///
28    /// To use this, pass a string specifying the `name` of the type which is
29    /// returning the error, and the `length` in bytes which its constructor
30    /// expects.
31    BytesLength {
32        name: &'static str,
33        length: usize,
34    },
35    /// The verification equation wasn't satisfied
36    Verify,
37    /// Two arrays did not match in size, making the called signature
38    /// verification method impossible.
39    #[cfg(feature = "batch")]
40    ArrayLength {
41        name_a: &'static str,
42        length_a: usize,
43        name_b: &'static str,
44        length_b: usize,
45        name_c: &'static str,
46        length_c: usize,
47    },
48    /// An ed25519ph signature can only take up to 255 octets of context.
49    #[cfg(feature = "digest")]
50    PrehashedContextLength,
51    /// A mismatched (public, secret) key pair.
52    MismatchedKeypair,
53}
54
55impl Display for InternalError {
56    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
57        match *self {
58            InternalError::PointDecompression => write!(f, "Cannot decompress Edwards point"),
59            InternalError::ScalarFormat => write!(f, "Cannot use scalar with high-bit set"),
60            InternalError::BytesLength { name: n, length: l } => {
61                write!(f, "{} must be {} bytes in length", n, l)
62            }
63            InternalError::Verify => write!(f, "Verification equation was not satisfied"),
64            #[cfg(feature = "batch")]
65            InternalError::ArrayLength {
66                name_a: na,
67                length_a: la,
68                name_b: nb,
69                length_b: lb,
70                name_c: nc,
71                length_c: lc,
72            } => write!(
73                f,
74                "Arrays must be the same length: {} has length {},
75                              {} has length {}, {} has length {}.",
76                na, la, nb, lb, nc, lc
77            ),
78            #[cfg(feature = "digest")]
79            InternalError::PrehashedContextLength => write!(
80                f,
81                "An ed25519ph signature can only take up to 255 octets of context"
82            ),
83            InternalError::MismatchedKeypair => write!(f, "Mismatched Keypair detected"),
84        }
85    }
86}
87
88impl Error for InternalError {}
89
90/// Errors which may occur while processing signatures and keypairs.
91///
92/// This error may arise due to:
93///
94/// * Being given bytes with a length different to what was expected.
95///
96/// * A problem decompressing `r`, a curve point, in the `Signature`, or the
97///   curve point for a `PublicKey`.
98///
99/// * A problem with the format of `s`, a scalar, in the `Signature`.  This
100///   is only raised if the high-bit of the scalar was set.  (Scalars must
101///   only be constructed from 255-bit integers.)
102///
103/// * Failure of a signature to satisfy the verification equation.
104pub type SignatureError = ed25519::signature::Error;
105
106impl From<InternalError> for SignatureError {
107    #[cfg(not(feature = "alloc"))]
108    fn from(_err: InternalError) -> SignatureError {
109        SignatureError::new()
110    }
111
112    #[cfg(feature = "alloc")]
113    fn from(err: InternalError) -> SignatureError {
114        SignatureError::from_source(err)
115    }
116}
ed25519_dalek/errors.rs

ed25519_dalek/
errors.rs
