From 01bbce5bd186aaaf322e9e819488a1bd0cbe4cc4 Mon Sep 17 00:00:00 2001
From: ErvinsK <ervins.kampans@gmail.com>
Date: Fri, 31 Oct 2025 23:52:55 +0200
Subject: [PATCH] fix: Issue #506

---
 src/per/de.rs     |  5 +++--
 tests/issue506.rs | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)
 create mode 100644 tests/issue506.rs

diff --git a/src/per/de.rs b/src/per/de.rs
index 50d624ec..727c6a63 100644
--- a/src/per/de.rs
+++ b/src/per/de.rs
@@ -709,11 +709,12 @@ impl<'input, const RFC: usize, const EFC: usize> crate::Decoder for Decoder<'inp
     ) -> Result<T> {
         let mut octet_string = Vec::new();
         let codec = self.codec();
-
+        if codec == crate::Codec::Aper {
+            self.input = self.parse_padding(self.input)?;
+        }
         self.decode_extensible_container(constraints, |input, length| {
             let (input, part) = nom::bytes::streaming::take(length * 8)(input)
                 .map_err(|e| DecodeError::map_nom_err(e, codec))?;
-
             let mut bytes = part.to_bitvec();
             bytes.force_align();
             octet_string.extend_from_slice(bytes.as_raw_slice());
diff --git a/tests/issue506.rs b/tests/issue506.rs
new file mode 100644
index 00000000..886103b5
--- /dev/null
+++ b/tests/issue506.rs
@@ -0,0 +1,39 @@
+use rasn::prelude::*;
+
+/*
+World-Schema DEFINITIONS AUTOMATIC TAGS ::=
+BEGIN
+    A ::= SEQUENCE {
+	i			OCTET STRING (SIZE(3)),
+	t			OCTET STRING (SIZE(2)),
+	e			INTEGER OPTIONAL,
+	...
+}
+END
+*/
+
+#[doc = "SEQUENCE A"]
+#[derive(AsnType, Debug, Clone, Decode, Encode, PartialEq, Eq, Hash)]
+#[non_exhaustive]
+pub struct A {
+    pub i: FixedOctetString<3>,
+    pub t: FixedOctetString<2>,
+    pub e: Option<Integer>,
+}
+
+#[test]
+fn test_sequence_a() {
+    // Encoded byte array
+    let encoded_value = [0x00u8, 0x19, 0xf0, 0x45, 0x00, 0x01];
+    // Decoded ASN.1 structure
+    let original = A {
+        i: FixedOctetString::from([0x19, 0xf0, 0x45]),
+        t: FixedOctetString::from([0x00, 0x01]),
+        e: None,
+    };
+    let encoded = rasn::aper::encode(&original).expect("encode");
+    println!("Encoded: {:x?}", encoded);
+    assert_eq!(&encoded_value, &encoded[..]);
+    let decoded: A = rasn::aper::decode(&encoded).expect("decode");
+    assert_eq!(decoded, original);
+}