Allows to directly en-/decode [u8; N] to/from a base64 string, much like the already existing bytes_as_base64 allows for Vec<u8>.
Signed-off-by: Christoph Heiss <[email protected]> --- proxmox-serde/src/lib.rs | 91 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) diff --git a/proxmox-serde/src/lib.rs b/proxmox-serde/src/lib.rs index 28c3054d..c3ec4f41 100644 --- a/proxmox-serde/src/lib.rs +++ b/proxmox-serde/src/lib.rs @@ -159,3 +159,94 @@ pub mod string_as_base64 { <T as StrAsBase64>::de::<'de, D>(deserializer) } } + +/// Serialize `[u8; N]` or `Option<[u8; N]>` as base64 encoded. +/// +/// If you do not need the convenience of handling both [u8; N] and Option transparently, you could +/// also use [`proxmox_base64`] directly. +/// +/// Usage example: +/// ``` +/// use serde::{Deserialize, Serialize}; +/// +/// #[derive(Debug, Deserialize, PartialEq, Serialize)] +/// struct Foo { +/// #[serde(with = "proxmox_serde::byte_array_as_base64")] +/// data: [u8; 4], +/// } +/// +/// let obj = Foo { data: [1, 2, 3, 4] }; +/// let json = serde_json::to_string(&obj).unwrap(); +/// assert_eq!(json, r#"{"data":"AQIDBA=="}"#); +/// +/// let deserialized: Foo = serde_json::from_str(&json).unwrap(); +/// assert_eq!(obj, deserialized); +/// ``` +pub mod byte_array_as_base64 { + use serde::{Deserialize, Deserializer, Serializer}; + + /// Private trait to enable `byte_array_as_base64` for `Option<[u8; N]>` in addition to `[u8; N]`. + #[doc(hidden)] + pub trait ByteArrayAsBase64<const N: usize>: Sized { + fn ser<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>; + fn de<'de, D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>; + } + + fn finish_deserializing<'de, const N: usize, D: Deserializer<'de>>( + string: String, + ) -> Result<[u8; N], D::Error> { + use serde::de::Error; + + let vec = proxmox_base64::decode(string).map_err(|err| { + let msg = format!("base64 decode: {}", err); + Error::custom(msg) + })?; + + vec.as_slice().try_into().map_err(|_| { + let msg = format!("expected {N} bytes, got {}", vec.len()); + Error::custom(msg) + }) + } + + impl<const N: usize> ByteArrayAsBase64<N> for [u8; N] { + fn ser<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> { + serializer.serialize_str(&proxmox_base64::encode(self)) + } + + fn de<'de, D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> { + finish_deserializing::<'de, N, D>(String::deserialize(deserializer)?) + } + } + + impl<const N: usize> ByteArrayAsBase64<N> for Option<[u8; N]> { + fn ser<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> { + match self { + Some(s) => Self::ser(&Some(*s), serializer), + None => serializer.serialize_none(), + } + } + + fn de<'de, D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> { + match Option::<String>::deserialize(deserializer)? { + Some(s) => Ok(Some(finish_deserializing::<'de, N, D>(s)?)), + None => Ok(None), + } + } + } + + pub fn serialize<const N: usize, S, T>(data: &T, serializer: S) -> Result<S::Ok, S::Error> + where + S: Serializer, + T: ByteArrayAsBase64<N>, + { + <T as ByteArrayAsBase64<N>>::ser(data, serializer) + } + + pub fn deserialize<'de, const N: usize, D, T>(deserializer: D) -> Result<T, D::Error> + where + D: Deserializer<'de>, + T: ByteArrayAsBase64<N>, + { + <T as ByteArrayAsBase64<N>>::de::<'de, D>(deserializer) + } +} -- 2.52.0 _______________________________________________ pve-devel mailing list [email protected] https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
