deb: make sure to have the right apt keyrings

src/distro_info.rs

@@ -13,6 +13,7 @@ struct SeriesInfo {
 #[derive(Debug, Deserialize)]
 struct DistData {
     base_url: String,
+    archive_keyring: String,
     pockets: Vec<String>,
     series: SeriesInfo,
 }
@@ -124,6 +125,27 @@ pub fn get_base_url(dist: &str) -> String {
     DATA.dist.get(dist).unwrap().base_url.clone()
 }
 
+/// Obtain the URL for the archive keyring of a distribution series
+pub async fn get_keyring_url(series: &str) -> Result<String, Box<dyn Error>> {
+    let dist = get_dist_from_series(series).await?;
+    let dist_data = DATA
+        .dist
+        .get(&dist)
+        .ok_or(format!("Unsupported distribution: {}", dist))?;
+
+    // For Debian, we need the series number to form the keyring URL
+    if dist == "debian" {
+        let series_num = get_debian_series_number(series).await?.unwrap();
+        // Replace {series_num} placeholder with the actual series number
+        Ok(dist_data
+            .archive_keyring
+            .replace("{series_num}", &series_num))
+    } else {
+        // For other distributions like Ubuntu, use the keyring directly
+        Ok(dist_data.archive_keyring.clone())
+    }
+}
+
 /// Obtain the URL for the 'Release' file of a distribution series
 fn get_release_url(base_url: &str, series: &str, pocket: &str) -> String {
     let pocket_full = if pocket.is_empty() {
@@ -159,6 +181,44 @@ pub async fn get_components(
     Err("Components not found.".into())
 }
 
+/// Map a Debian series name to its version number
+pub async fn get_debian_series_number(series: &str) -> Result<Option<String>, Box<dyn Error>> {
+    let series_info = &DATA.dist.get("debian").unwrap().series;
+    let content = if Path::new(series_info.local.as_str()).exists() {
+        std::fs::read_to_string(series_info.local.as_str())?
+    } else {
+        reqwest::get(series_info.network.as_str())
+            .await?
+            .text()
+            .await?
+    };
+
+    let mut rdr = csv::ReaderBuilder::new()
+        .flexible(true)
+        .from_reader(content.as_bytes());
+
+    let headers = rdr.headers()?.clone();
+    let series_idx = headers
+        .iter()
+        .position(|h| h == "series")
+        .ok_or("Column 'series' not found")?;
+    let version_idx = headers
+        .iter()
+        .position(|h| h == "version")
+        .ok_or("Column 'version' not found")?;
+
+    for result in rdr.records() {
+        let record = result?;
+        if let (Some(s), Some(v)) = (record.get(series_idx), record.get(version_idx))
+            && s.to_lowercase() == series.to_lowercase()
+        {
+            return Ok(Some(v.to_string()));
+        }
+    }
+
+    Ok(None)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -182,4 +242,20 @@ mod tests {
         assert_eq!(get_dist_from_series("sid").await.unwrap(), "debian");
         assert_eq!(get_dist_from_series("noble").await.unwrap(), "ubuntu");
     }
+
+    #[tokio::test]
+    async fn test_get_debian_series_number() {
+        // Test with known Debian series
+        let bookworm_number = get_debian_series_number("bookworm").await.unwrap();
+        assert!(bookworm_number.is_some());
+        assert_eq!(bookworm_number.unwrap(), "12");
+
+        let trixie_number = get_debian_series_number("trixie").await.unwrap();
+        assert!(trixie_number.is_some());
+        assert_eq!(trixie_number.unwrap(), "13");
+
+        // Test with unknown series
+        let unknown_number = get_debian_series_number("unknown").await.unwrap();
+        assert!(unknown_number.is_none());
+    }
 }