Re: [PATCH proxmox-backup 1/2] client: allow skipping signature check on previous manifest fetching

["Fabian Grünbichler" <f.gruenbichler@proxmox.com>]

On April 29, 2026 11:28 am, Christian Ebner wrote:
> Extends the BackupWriter implementation by a method which allows to
> download the previous manifest from a PBS instance, but skipping the
> signature check even if the backup writer has a crypt_config set.
> 
> This will be used to silence misleading logs during encrypting push
> sync jobs, by performing the signature check on the call site
> instead.
> 
> Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
> ---
>  pbs-client/src/backup_writer.rs | 22 +++++++++++++++++++---
>  1 file changed, 19 insertions(+), 3 deletions(-)
> 
> diff --git a/pbs-client/src/backup_writer.rs b/pbs-client/src/backup_writer.rs
> index 49aff3fdd..ea990dbde 100644
> --- a/pbs-client/src/backup_writer.rs
> +++ b/pbs-client/src/backup_writer.rs
> @@ -735,8 +735,25 @@ impl BackupWriter {
>          })
>      }
>  
> -    /// Download backup manifest (index.json) of last backup
> +    /// Download backup manifest (index.json) of last backup, checking the signature
> +    /// using the backup writer's crypt config.
>      pub async fn download_previous_manifest(&self) -> Result<BackupManifest, Error> {

since we only have two callsites for this (one for each variant ;)), couldn't we just switch to

download_previous_manifest(&self, check_signature: bool)

? would make the writer interface a little less bloated..

> +        let manifest = self
> +            .download_previous_manifest_without_signature_check()
> +            .await?;
> +
> +        if let Some(crypt_config) = &self.crypt_config {
> +            manifest.check_signature(crypt_config)?;
> +        }
> +
> +        Ok(manifest)
> +    }
> +
> +    /// Download backup manifest (index.json) of last backup, but skips the signature
> +    /// check by not providing the crypt config when parsing the manifest from the data blob.
> +    pub async fn download_previous_manifest_without_signature_check(
> +        &self,
> +    ) -> Result<BackupManifest, Error> {
>          let mut raw_data = Vec::with_capacity(64 * 1024);
>  
>          let param = json!({ "archive-name": MANIFEST_BLOB_NAME.to_string() });
> @@ -748,8 +765,7 @@ impl BackupWriter {
>          // no expected digest available
>          let data = blob.decode(self.crypt_config.as_ref().map(Arc::as_ref), None)?;

pre-existing, but this makes no sense - manifests are never encrypted,
so passing the key here is just misleading?

>  
> -        let manifest =
> -            BackupManifest::from_data(&data[..], self.crypt_config.as_ref().map(Arc::as_ref))?;
> +        let manifest = BackupManifest::from_data(&data[..], None)?;
>  
>          Ok(manifest)
>      }
> -- 
> 2.47.3
> 
> 
> 
> 
> 
>