implementation of coserv data model

Cargo.toml

@@ -28,6 +28,7 @@ derive_more = { version = "^2", features = [
     "deref",
     "deref_mut",
     "constructor",
+    "display",
 ] }
 serde_json = {version = "1.0.140", features = [
     "raw_value",
@@ -38,3 +39,7 @@ jsonwebkey = "0.3.5"
 semver = "1.0.27"
 mime = "0.3.17"
 thiserror = "2.0.17"
+corim-rs = { git = "https://github.com/veraison/corim-rs" }
+chrono = "0.4.42"
+cmw = { git = "https://github.com/veraison/rust-cmw" }
+base64 = "0.22.1"

src/coserv/common.rs

@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: Apache-2.0
+
+use chrono::{format::SecondsFormat, DateTime, FixedOffset, Local};
+use corim_rs::generate_tagged;
+use derive_more::From;
+use std::ops::Add;
+
+use serde::{
+    de::{Deserialize, Deserializer, Error},
+    ser::{Serialize, SerializeMap, Serializer},
+};
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, serde::Deserialize, serde::Serialize)]
+pub struct Tstr(String); // Time string
+
+generate_tagged!((
+    0,
+    TaggedTstr,
+    Tstr,
+    "text string",
+    "representation of date/time string using CBOR tag 0"
+));
+
+/// Represents timestamps used in coserv query and results
+#[derive(Debug, From, Default, PartialEq, Eq, PartialOrd, Ord, Clone)]
+pub struct TimeStamp(pub DateTime<FixedOffset>);
+
+/// Re-export to perform arithmetic on TimeStamp.
+pub use chrono::TimeDelta;
+
+impl TimeStamp {
+    pub fn now() -> Self {
+        Local::now().fixed_offset().into()
+    }
+
+    pub fn add(&self, delta: TimeDelta) -> Self {
+        self.0.add(delta).into()
+    }
+}
+
+impl Serialize for TimeStamp {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        //  Section 3.3 of [RFC4287]
+        let tagged_time = TaggedTstr::from(Tstr(self.0.to_rfc3339_opts(SecondsFormat::Secs, true)));
+        tagged_time.serialize(serializer)
+    }
+}
+
+impl<'de> Deserialize<'de> for TimeStamp {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let time_tstr = TaggedTstr::deserialize(deserializer)?.0 .0 .0;
+        Ok(TimeStamp(
+            DateTime::parse_from_rfc3339(&time_tstr).map_err(D::Error::custom)?,
+        ))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_time_string() {
+        let tests: Vec<(TimeStamp, Vec<u8>)> = vec![
+            (
+                TimeStamp(DateTime::parse_from_rfc3339("2020-09-04T18:34:39+05:30").unwrap()),
+                vec![
+                    0xc0, 0x78, 0x19, // tag(0), text(25)
+                    0x32, 0x30, 0x32, 0x30, 0x2d, 0x30, 0x39, 0x2d, 0x30, 0x34, 0x54, 0x31, 0x38,
+                    0x3a, 0x33, 0x34, 0x3a, 0x33, 0x39, 0x2b, 0x30, 0x35, 0x3a, 0x33, 0x30,
+                ],
+            ),
+            (
+                TimeStamp(DateTime::parse_from_rfc3339("2020-09-04T13:04:39+00:00").unwrap()),
+                vec![
+                    0xc0, 0x74, // tag(0), text(20)
+                    0x32, 0x30, 0x32, 0x30, 0x2d, 0x30, 0x39, 0x2d, 0x30, 0x34, 0x54, 0x31, 0x33,
+                    0x3a, 0x30, 0x34, 0x3a, 0x33, 0x39, 0x5a,
+                ],
+            ),
+            (
+                TimeStamp(DateTime::parse_from_rfc3339("2020-09-04T13:04:39Z").unwrap()),
+                vec![
+                    0xc0, 0x74, // tag(0), text(20)
+                    0x32, 0x30, 0x32, 0x30, 0x2d, 0x30, 0x39, 0x2d, 0x30, 0x34, 0x54, 0x31, 0x33,
+                    0x3a, 0x30, 0x34, 0x3a, 0x33, 0x39, 0x5a,
+                ],
+            ),
+        ];
+
+        for (i, (time, expected_cbor)) in tests.iter().enumerate() {
+            let mut actual_cbor: Vec<u8> = vec![];
+            ciborium::into_writer(&time, &mut actual_cbor).unwrap();
+            assert_eq!(*expected_cbor, actual_cbor, "ser at index {i}: {time:?}");
+
+            let time_de: TimeStamp = ciborium::from_reader(actual_cbor.as_slice()).unwrap();
+            assert_eq!(*time, time_de, "de at index {i}: {time:?} != {time_de:?}");
+        }
+
+        let err: Result<TimeStamp, _> =
+            ciborium::from_reader([0xc0_u8, 0x63, 0x66, 0x6f, 0x6f].as_slice());
+        assert!(err.is_err());
+    }
+
+    #[test]
+    fn test_time_add() {
+        let base_time = DateTime::parse_from_rfc3339("2020-09-04T00:00:00Z").unwrap();
+        let expected_time = DateTime::parse_from_rfc3339("2020-09-04T01:00:00Z").unwrap();
+        let result = base_time.add(TimeDelta::hours(1));
+        assert_eq!(result, expected_time);
+    }
+}