openpgp: Add and use a module for time and duration conversion.

3 files changed, 63 insertions, 25 deletions

diff --git a/openpgp/src/conversions.rs b/openpgp/src/conversions.rs
new file mode 100644
index 00000000..b2dfc549
--- /dev/null
+++ b/openpgp/src/conversions.rs
@@ -0,0 +1,54 @@
+//! Conversions for primitive OpenPGP types.
+
+use time;
+
+use Error;
+use Result;
+
+/// Conversions for OpenPGP time stamps.
+pub trait Time {
+    /// Converts an OpenPGP time stamp to broken-down time.
+    fn from_pgp(u32) -> Self;
+    /// Converts broken-down time to an OpenPGP time stamp.
+    fn to_pgp(&self) -> Result<u32>;
+}
+
+impl Time for time::Tm {
+    fn from_pgp(timestamp: u32) -> Self {
+        time::at_utc(time::Timespec::new(timestamp as i64, 0))
+    }
+
+    fn to_pgp(&self) -> Result<u32> {
+        let epoch = self.to_timespec().sec;
+        if epoch > ::std::u32::MAX as i64 {
+            return Err(Error::InvalidArgument(
+                format!("Time exceeds u32 epoch: {:?}", self))
+                       .into());
+        }
+        Ok(epoch as u32)
+    }
+}
+
+/// Conversions for OpenPGP durations.
+pub trait Duration {
+    /// Converts an OpenPGP duration to ISO 8601 time duration.
+    fn from_pgp(u32) -> Self;
+    /// Converts ISO 8601 time duration to an OpenPGP duration.
+    fn to_pgp(&self) -> Result<u32>;
+}
+
+impl Duration for time::Duration {
+    fn from_pgp(duration: u32) -> Self {
+        time::Duration::seconds(duration as i64)
+    }
+
+    fn to_pgp(&self) -> Result<u32> {
+        let secs = self.num_seconds();
+        if secs > ::std::u32::MAX as i64 {
+            return Err(Error::InvalidArgument(
+                format!("Duration exceeds u32: {:?}", self))
+                       .into());
+        }
+        Ok(secs as u32)
+    }
+}
diff --git a/openpgp/src/lib.rs b/openpgp/src/lib.rs
index b24e88ee..72fa4911 100644
--- a/openpgp/src/lib.rs
+++ b/openpgp/src/lib.rs
@@ -67,6 +67,8 @@ pub mod autocrypt;
 pub mod ctb;
 use ctb::{CTB, CTBOld, CTBNew};
 
+pub mod conversions;
+
 pub mod packet;
 use packet::{BodyLength, Header, Container};
 pub mod subpacket;
diff --git a/openpgp/src/subpacket.rs b/openpgp/src/subpacket.rs
index 8e589e2d..84d34ad9 100644
--- a/openpgp/src/subpacket.rs
+++ b/openpgp/src/subpacket.rs
@@ -77,6 +77,10 @@ use constants::{
     HashAlgorithm,
     PublicKeyAlgorithm,
 };
+use conversions::{
+    Time,
+    Duration,
+};
 
 #[cfg(test)]
 use std::path::PathBuf;
@@ -1233,28 +1237,6 @@ const KEY_FLAG_AUTHENTICATE: u8 = 0x20;
 /// than one person.
 const KEY_FLAG_GROUP_KEY: u8 = 0x80;
 
-/// Converts structured time to OpenPGP time.
-fn tm2pgp(t: time::Tm) -> Result<u32> {
-    let epoch = t.to_timespec().sec;
-    if epoch > ::std::u32::MAX as i64 {
-        return Err(Error::InvalidArgument(
-            format!("Time exceeds u32 epoch: {:?}", t))
-                   .into());
-    }
-    Ok(epoch as u32)
-}
-
-/// Converts structured duration to OpenPGP duration.
-fn duration2pgp(d: time::Duration) -> Result<u32> {
-    let secs = d.num_seconds();
-    if secs > ::std::u32::MAX as i64 {
-        return Err(Error::InvalidArgument(
-            format!("Duration exceeds u32 epoch: {:?}", d))
-                   .into());
-    }
-    Ok(secs as u32)
-}
-
 impl Signature {
     /// Returns the *last* instance of the specified subpacket.
     fn subpacket<'a>(&'a self, tag: SubpacketTag) -> Option<Subpacket<'a>> {
@@ -1317,7 +1299,7 @@ impl Signature {
     pub fn set_signature_creation_time(&mut self, creation_time: time::Tm)
                                        -> Result<()> {
         self.hashed_area.replace(Subpacket::new(
-            SubpacketValue::SignatureCreationTime(tm2pgp(creation_time)?),
+            SubpacketValue::SignatureCreationTime(creation_time.to_pgp()?),
             true)?)
     }
 
@@ -1352,7 +1334,7 @@ impl Signature {
                                        -> Result<()> {
         if let Some(e) = expiration {
             self.hashed_area.replace(Subpacket::new(
-                SubpacketValue::SignatureExpirationTime(duration2pgp(e)?),
+                SubpacketValue::SignatureExpirationTime(e.to_pgp()?),
                 true)?)
         } else {
             self.hashed_area.remove_all(SubpacketTag::SignatureExpirationTime);
@@ -1577,7 +1559,7 @@ impl Signature {
                                    -> Result<()> {
         if let Some(e) = expiration {
             self.hashed_area.replace(Subpacket::new(
-                SubpacketValue::KeyExpirationTime(duration2pgp(e)?),
+                SubpacketValue::KeyExpirationTime(e.to_pgp()?),
                 true)?)
         } else {
             self.hashed_area.remove_all(SubpacketTag::KeyExpirationTime);