Function decode_base64_or_hex 

pub fn decode_base64_or_hex(input: &str) -> Result<Bytes, CoreError>

Decodes data that may be either base64 or hex encoded. Tries base64 first, then falls back to hex.

This matches the Go implementation’s permissive decoding behavior.

Warning: Ambiguous inputs

Strings that are valid in both base64 and hex will always be decoded as base64. For example, "AABB" is valid hex ([0xAA, 0xBB]) and valid base64 ([0x00, 0x00, 0x1B]). Because base64 is tried first, the base64 interpretation wins. This is intentional — the Go SDK uses the same heuristic. Callers who know the encoding should use decode_base64 or decode_hex directly.

Arguments

• input - The encoded string (base64 or hex)

Returns

The decoded bytes as Bytes.