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//! Crate-wide error type.
use core::fmt;
/// Convenience `Result` alias used throughout the crate.
pub type Result<T> = core::result::Result<T, Error>;
/// Errors produced by `puressh`.
#[non_exhaustive]
#[derive(Debug)]
pub enum Error {
/// A wire-format value was malformed or truncated.
Format(&'static str),
/// Negotiation failed: no common algorithm between peers.
NoCommonAlgorithm(&'static str),
/// A protocol-level invariant was violated by the peer.
Protocol(&'static str),
/// MAC verification failed on an inbound packet.
BadMac,
/// AEAD authentication tag did not match.
BadTag,
/// Decryption produced an invalid plaintext (e.g. bad padding).
BadPadding,
/// Host-key signature failed to verify.
BadSignature,
/// Peer's host key was rejected by policy / known-hosts.
HostKeyRejected,
/// Authentication was refused or exhausted.
AuthFailed,
/// Requested channel operation is not valid in the current state.
BadChannelState,
/// A feature was requested that this build does not support.
Unsupported(&'static str),
/// I/O error (only with `std`).
#[cfg(feature = "std")]
Io(std::io::Error),
/// Error originating from the `purecrypto` backend.
Crypto(&'static str),
/// A configuration value supplied to the library was internally
/// inconsistent or insufficient (e.g. a `HostKeyPolicy::KnownHosts`
/// without a connect target). Distinct from `Protocol` so callers can
/// tell "I configured this wrong" from "the peer is misbehaving".
Config(&'static str),
/// An OpenSSH certificate's validity window has already ended
/// (`now >= valid_before`).
CertExpired,
/// An OpenSSH certificate is not yet valid (`now < valid_after`).
CertNotYetValid,
/// The requested principal (host name or login user) is not listed in
/// the certificate's `valid principals`.
CertPrincipalMismatch,
/// The certificate's `type` field does not match the context it is being
/// used in (a host cert presented for user auth, or vice versa).
CertTypeMismatch,
/// The certificate carries a critical option this build does not
/// understand; per the spec such a certificate MUST be rejected.
CertUnknownCriticalOption,
/// The CA signature over the certificate failed to verify, or the CA
/// signature algorithm is not in the permitted `CASignatureAlgorithms`
/// set.
CertBadCaSignature,
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Error::Format(s) => write!(f, "ssh wire format: {s}"),
Error::NoCommonAlgorithm(s) => write!(f, "no common {s}"),
Error::Protocol(s) => write!(f, "protocol error: {s}"),
Error::BadMac => f.write_str("bad MAC"),
Error::BadTag => f.write_str("bad AEAD tag"),
Error::BadPadding => f.write_str("bad padding"),
Error::BadSignature => f.write_str("bad signature"),
Error::HostKeyRejected => f.write_str("host key rejected"),
Error::AuthFailed => f.write_str("authentication failed"),
Error::BadChannelState => f.write_str("bad channel state"),
Error::Unsupported(s) => write!(f, "unsupported: {s}"),
#[cfg(feature = "std")]
Error::Io(e) => write!(f, "io: {e}"),
Error::Crypto(s) => write!(f, "crypto: {s}"),
Error::Config(s) => write!(f, "config error: {s}"),
Error::CertExpired => f.write_str("certificate has expired"),
Error::CertNotYetValid => f.write_str("certificate is not yet valid"),
Error::CertPrincipalMismatch => f.write_str("certificate principal not authorized"),
Error::CertTypeMismatch => f.write_str("certificate type mismatch"),
Error::CertUnknownCriticalOption => {
f.write_str("certificate has an unknown critical option")
}
Error::CertBadCaSignature => f.write_str("certificate CA signature invalid"),
}
}
}
#[cfg(feature = "std")]
impl std::error::Error for Error {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
match self {
Error::Io(e) => Some(e),
_ => None,
}
}
}
#[cfg(feature = "std")]
impl From<std::io::Error> for Error {
fn from(e: std::io::Error) -> Self {
Error::Io(e)
}
}