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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This bug was recently reported by a user of
Edit: FTR the release question is discussed here: #475 |
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Yep, #475 is the place to ask |
sini
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Aug 14, 2026
overhacked#56) ssh-agent-lib 0.5.1 typed identities as ssh_key::public::KeyData, which cannot represent an OpenSSH certificate: request_identities decoded a ...-cert-v01@openssh.com blob into a lossy opaque key and re-serialized a truncated identity, so any upstream agent holding a certificate made `ssh-add -l` fail with "incomplete message" and (with overhacked#94) silently dropped every other agent's keys. Bump to ssh-agent-lib 0.6.0, whose PublicCredential (Key | Cert) round-trips certificates losslessly in both identity listings and sign requests. Key the known-keys map by credential.key_data() so a certificate, its bare public key, and the sign request ssh issues all resolve to the same upstream agent. Note: certificates with valid_before = u64::MAX ("Valid: forever") still fail to decode under the ssh-key 0.6.7 that ssh-agent-lib 0.6.0 builds on (RustCrypto/SSH#504, fixed in ssh-key 0.7). Certificates with a real expiration -- as OpenSSH and correctly configured issuers produce -- work now.
sini
added a commit
to sini/ssh-agent-mux
that referenced
this pull request
Aug 14, 2026
overhacked#56) ssh-agent-lib 0.5.1 typed identities as ssh_key::public::KeyData, which cannot represent an OpenSSH certificate: request_identities decoded a ...-cert-v01@openssh.com blob into a lossy opaque key and re-serialized a truncated identity, so any upstream agent holding a certificate made `ssh-add -l` fail with "incomplete message" and (with overhacked#94) silently dropped every other agent's keys. Bump to ssh-agent-lib 0.6.0, whose PublicCredential (Key | Cert) round-trips certificates losslessly in both identity listings and sign requests. Key the known-keys map by credential.key_data() so a certificate, its bare public key, and the sign request ssh issues all resolve to the same upstream agent. Note: certificates with valid_before = u64::MAX ("Valid: forever") still fail to decode under the ssh-key 0.6.7 that ssh-agent-lib 0.6.0 builds on (RustCrypto/SSH#504, fixed in ssh-key 0.7). Certificates with a real expiration -- as OpenSSH and correctly configured issuers produce -- work now.
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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