diff --git a/src/bin/proxmox-backup-client.rs b/src/bin/proxmox-backup-client.rs
index 1fd2c54a..66e6a3ba 100644
--- a/src/bin/proxmox-backup-client.rs
+++ b/src/bin/proxmox-backup-client.rs
@@ -485,22 +485,9 @@ fn dump_catalog(
             true,
         ).await?;
 
-        let tmpfile = std::fs::OpenOptions::new()
-            .write(true)
-            .read(true)
-            .custom_flags(libc::O_TMPFILE)
-            .open("/tmp")?;
-
         let manifest = client.download_manifest().await?;
 
-        let tmpfile = client.download(CATALOG_NAME, tmpfile).await?;
-
-        let index = DynamicIndexReader::new(tmpfile)
-            .map_err(|err| format_err!("unable to read catalog index - {}", err))?;
-
-        // Note: do not use values stored in index (not trusted) - instead, computed them again
-        let (csum, size) = index.compute_csum();
-        manifest.verify_file(CATALOG_NAME, &csum, size)?;
+        let index = client.download_dynamic_index(&manifest, CATALOG_NAME).await?;
 
         let most_used = index.find_most_used_chunks(8);
 
@@ -1077,14 +1064,8 @@ async fn restore_do(param: Value) -> Result<Value, Error> {
         }
 
     } else if server_archive_name.ends_with(".didx") {
-        let tmpfile = client.download(&server_archive_name, tmpfile).await?;
 
-        let index = DynamicIndexReader::new(tmpfile)
-            .map_err(|err| format_err!("unable to read dynamic index '{}' - {}", archive_name, err))?;
-
-        // Note: do not use values stored in index (not trusted) - instead, computed them again
-        let (csum, size) = index.compute_csum();
-        manifest.verify_file(&server_archive_name, &csum, size)?;
+        let index = client.download_dynamic_index(&manifest, &server_archive_name).await?;
 
         let most_used = index.find_most_used_chunks(8);
 
@@ -1753,23 +1734,10 @@ async fn mount_do(param: Value, pipe: Option<RawFd>) -> Result<Value, Error> {
         true,
     ).await?;
 
-    let tmpfile = std::fs::OpenOptions::new()
-        .write(true)
-        .read(true)
-        .custom_flags(libc::O_TMPFILE)
-        .open("/tmp")?;
-
     let manifest = client.download_manifest().await?;
 
     if server_archive_name.ends_with(".didx") {
-        let tmpfile = client.download(&server_archive_name, tmpfile).await?;
-        let index = DynamicIndexReader::new(tmpfile)
-            .map_err(|err| format_err!("unable to read dynamic index '{}' - {}", archive_name, err))?;
-
-        // Note: do not use values stored in index (not trusted) - instead, computed them again
-        let (csum, size) = index.compute_csum();
-        manifest.verify_file(&server_archive_name, &csum, size)?;
-
+        let index = client.download_dynamic_index(&manifest, &server_archive_name).await?;
         let most_used = index.find_most_used_chunks(8);
         let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config, most_used);
         let reader = BufferedDynamicReader::new(index, chunk_reader);
diff --git a/src/client/backup_reader.rs b/src/client/backup_reader.rs
index 3c30a2f9..01bba7f7 100644
--- a/src/client/backup_reader.rs
+++ b/src/client/backup_reader.rs
@@ -1,6 +1,7 @@
 use failure::*;
 use std::io::Write;
 use std::sync::Arc;
+use std::os::unix::fs::OpenOptionsExt;
 
 use chrono::{DateTime, Utc};
 use serde_json::{json, Value};
@@ -133,4 +134,32 @@ impl BackupReader {
 
         BackupManifest::try_from(json)
     }
+
+    /// Download dynamic index file
+    ///
+    /// This creates a temorary file in /tmp (using O_TMPFILE). The index is verified using
+    /// the provided manifest.
+    pub async fn download_dynamic_index(
+        &self,
+        manifest: &BackupManifest,
+        name: &str,
+    ) -> Result<DynamicIndexReader, Error> {
+
+        let tmpfile = std::fs::OpenOptions::new()
+            .write(true)
+            .read(true)
+            .custom_flags(libc::O_TMPFILE)
+            .open("/tmp")?;
+
+        let tmpfile = self.download(name, tmpfile).await?;
+
+        let index = DynamicIndexReader::new(tmpfile)
+            .map_err(|err| format_err!("unable to read dynamic index '{}' - {}", name, err))?;
+
+        // Note: do not use values stored in index (not trusted) - instead, computed them again
+        let (csum, size) = index.compute_csum();
+        manifest.verify_file(name, &csum, size)?;
+
+        Ok(index)
+    }
 }