diff options
Diffstat (limited to 'openpgp/src/cert/builder.rs')
| -rw-r--r-- | openpgp/src/cert/builder.rs | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/openpgp/src/cert/builder.rs b/openpgp/src/cert/builder.rs index f5667cd7..c771c1ce 100644 --- a/openpgp/src/cert/builder.rs +++ b/openpgp/src/cert/builder.rs @@ -278,9 +278,21 @@ impl CertBuilder { /// Sets the creation time. /// - /// If `creation_time` is `None`, the default, this causes the + /// If `creation_time` is not `None`, this causes the /// `CertBuilder` to use that time when [`CertBuilder::generate`] - /// is called. + /// is called. If it is `None`, the default, then the current + /// time minus 60 seconds is used as creation time. Backdating + /// the certificate by a minute has the advantage that the + /// certificate can immediately be customized: + /// + /// In order to reliably override a binding signature, the + /// overriding binding signature must be newer than the existing + /// signature. If, however, the existing signature is created + /// `now`, any newer signature must have a future creation time, + /// and is considered invalid by Sequoia. To avoid this, we + /// backdate certificate creation times (and hence binding + /// signature creation times), so that there is "space" between + /// the creation time and now for signature updates. /// /// Warning: this function takes a [`SystemTime`]. A `SystemTime` /// has a higher resolution, and a larger range than an OpenPGP @@ -942,7 +954,11 @@ impl CertBuilder { use std::convert::TryFrom; let creation_time = - self.creation_time.unwrap_or_else(std::time::SystemTime::now); + self.creation_time.unwrap_or_else(|| { + use crate::packet::signature::SIG_BACKDATE_BY; + time::SystemTime::now() - + time::Duration::new(SIG_BACKDATE_BY, 0) + }); let mut packets = Vec::<Packet>::with_capacity( 1 + 1 + self.subkeys.len() + self.userids.len() |