ssh-key: allow u64::MAX as "no expiry" sentinel in UnixTime#504
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OpenSSH PROTOCOL.certkeys specifies that valid_before=0xffffffffffffffff (u64::MAX) means the certificate never expires. Previously UnixTime::new rejected this value because it exceeds MAX_SECS (i64::MAX), causing Certificate parsing to fail for any cert generated without an explicit validity window (e.g. ssh-keygen -s ca -h key.pub without -V). Add FOREVER_SECS=u64::MAX constant. In new(), cap its SystemTime representation at MAX_SECS to keep a valid SystemTime while preserving the raw secs value for round-trip encoding correctness. Fixes: RustCrypto#503
tarcieri
changed the title
u64::MAX as "no expiry" sentinel in UnixTime
tarcieri
reviewed
May 10, 2026
| #[cfg(not(feature = "std"))] | ||
| pub fn new(secs: u64) -> Result<Self> { | ||
| if secs <= MAX_SECS { | ||
| if secs == FOREVER_SECS || secs <= MAX_SECS { |
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Seems like the FOREVER_SECS case could use a convenience constructor like pub fn new_non_expiring or something to that effect, but that can be added as a followup
tarcieri
approved these changes
May 10, 2026
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OpenSSH PROTOCOL.certkeys specifies that valid_before=0xffffffffffffffff (u64::MAX) means the certificate never expires. Previously UnixTime::new rejected this value because it exceeds MAX_SECS (i64::MAX), causing Certificate parsing to fail for any cert generated without an explicit validity window (e.g. ssh-keygen -s ca -h key.pub without -V).
Add FOREVER_SECS=u64::MAX constant. In new(), cap its SystemTime representation at MAX_SECS to keep a valid SystemTime while preserving the raw secs value for round-trip encoding correctness.
Fixes: #503