Revert "openpgp: Remove SignatureBuilder::set_key_expiration_time."

This reverts commit e18c79c37db27d138caeed67025d8b247410c3b8.

1 files changed, 26 insertions, 0 deletions

diff --git a/openpgp/src/packet/signature/subpacket.rs b/openpgp/src/packet/signature/subpacket.rs
index 0510acc3..84f3c570 100644
--- a/openpgp/src/packet/signature/subpacket.rs
+++ b/openpgp/src/packet/signature/subpacket.rs
@@ -4564,6 +4564,32 @@ impl signature::SignatureBuilder {
         Ok(self)
     }
 
+    /// Sets the value of the Key Expiration Time subpacket.
+    ///
+    /// If `None` is given, any expiration subpacket is removed.
+    pub fn set_key_expiration_time<P, R>(
+        self,
+        key: &Key<P, R>,
+        expiration: Option<time::SystemTime>)
+        -> Result<Self>
+        where P: key::KeyParts,
+              R: key::KeyRole,
+    {
+        if let Some(e) = expiration.map(crate::types::normalize_systemtime) {
+            let ct = key.creation_time();
+            let vp = match e.duration_since(ct) {
+                Ok(v) => v,
+                Err(_) => return Err(Error::InvalidArgument(
+                    format!("Expiration time {:?} predates creation time \
+                             {:?}", e, ct)).into()),
+            };
+
+            self.set_key_validity_period(Some(vp))
+        } else {
+            self.set_key_validity_period(None)
+        }
+    }
+
     /// Sets the Preferred Symmetric Algorithms subpacket.
     ///
     /// Replaces any [Preferred Symmetric Algorithms subpacket] in the