From 569f1bb19b29a0f855df17a8a49f60feca5f334b Mon Sep 17 00:00:00 2001
From: Kedar Sovani <kedars@gmail.com>
Date: Sat, 31 Dec 2022 11:04:33 +0530
Subject: [PATCH] OpCreds: ICAC is optional and may not be added as part of
 commissioning

---
 matter/src/data_model/sdm/noc.rs  |  9 +++++++--
 matter/src/fabric.rs              | 20 +++++++++++++++-----
 matter/src/secure_channel/case.rs |  9 +++++++--
 3 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/matter/src/data_model/sdm/noc.rs b/matter/src/data_model/sdm/noc.rs
index 3812ed6..d03467e 100644
--- a/matter/src/data_model/sdm/noc.rs
+++ b/matter/src/data_model/sdm/noc.rs
@@ -141,8 +141,13 @@ impl NocCluster {
 
         let noc_value = Cert::new(r.noc_value.0).map_err(|_| NocStatus::InvalidNOC)?;
         info!("Received NOC as: {}", noc_value);
-        let icac_value = Cert::new(r.icac_value.0).map_err(|_| NocStatus::InvalidNOC)?;
-        info!("Received ICAC as: {}", icac_value);
+        let icac_value = if r.icac_value.0.len() != 0 {
+            let cert = Cert::new(r.icac_value.0).map_err(|_| NocStatus::InvalidNOC)?;
+            info!("Received ICAC as: {}", cert);
+            Some(cert)
+        } else {
+            None
+        };
 
         let fabric = Fabric::new(
             noc_data.key_pair,
diff --git a/matter/src/fabric.rs b/matter/src/fabric.rs
index 8f85504..f868664 100644
--- a/matter/src/fabric.rs
+++ b/matter/src/fabric.rs
@@ -52,7 +52,7 @@ pub struct Fabric {
     fabric_id: u64,
     key_pair: Box<dyn CryptoKeyPair>,
     pub root_ca: Cert,
-    pub icac: Cert,
+    pub icac: Option<Cert>,
     pub noc: Cert,
     pub ipk: KeySet,
     compressed_id: [u8; COMPRESSED_FABRIC_ID_LEN],
@@ -63,7 +63,7 @@ impl Fabric {
     pub fn new(
         key_pair: KeyPair,
         root_ca: Cert,
-        icac: Cert,
+        icac: Option<Cert>,
         noc: Cert,
         ipk: &[u8],
     ) -> Result<Self, Error> {
@@ -107,7 +107,7 @@ impl Fabric {
             fabric_id: 0,
             key_pair: Box::new(KeyPairDummy::new()?),
             root_ca: Cert::default(),
-            icac: Cert::default(),
+            icac: Some(Cert::default()),
             noc: Cert::default(),
             ipk: KeySet::default(),
             compressed_id: [0; COMPRESSED_FABRIC_ID_LEN],
@@ -165,8 +165,14 @@ impl Fabric {
         let mut key = [0u8; MAX_CERT_TLV_LEN];
         let len = self.root_ca.as_tlv(&mut key)?;
         psm.set_kv_slice(fb_key!(index, ST_RCA), &key[..len])?;
-        let len = self.icac.as_tlv(&mut key)?;
+
+        let len = if let Some(icac) = &self.icac {
+            icac.as_tlv(&mut key)?
+        } else {
+            0
+        };
         psm.set_kv_slice(fb_key!(index, ST_ICA), &key[..len])?;
+
         let len = self.noc.as_tlv(&mut key)?;
         psm.set_kv_slice(fb_key!(index, ST_NOC), &key[..len])?;
         psm.set_kv_slice(fb_key!(index, ST_IPK), self.ipk.epoch_key())?;
@@ -191,7 +197,11 @@ impl Fabric {
 
         let mut icac = Vec::new();
         psm.get_kv_slice(fb_key!(index, ST_ICA), &mut icac)?;
-        let icac = Cert::new(icac.as_slice())?;
+        let icac = if icac.len() != 0 {
+            Some(Cert::new(icac.as_slice())?)
+        } else {
+            None
+        };
 
         let mut noc = Vec::new();
         psm.get_kv_slice(fb_key!(index, ST_NOC), &mut noc)?;
diff --git a/matter/src/secure_channel/case.rs b/matter/src/secure_channel/case.rs
index c034532..d75bf96 100644
--- a/matter/src/secure_channel/case.rs
+++ b/matter/src/secure_channel/case.rs
@@ -475,7 +475,10 @@ impl Case {
         let mut tw = TLVWriter::new(&mut write_buf);
         tw.start_struct(TagType::Anonymous)?;
         tw.str16_as(TagType::Context(1), |buf| fabric.noc.as_tlv(buf))?;
-        tw.str16_as(TagType::Context(2), |buf| fabric.icac.as_tlv(buf))?;
+        if let Some(icac_cert) = &fabric.icac {
+            tw.str16_as(TagType::Context(2), |buf| icac_cert.as_tlv(buf))?
+        };
+
         tw.str8(TagType::Context(3), signature)?;
         tw.str8(TagType::Context(4), &resumption_id)?;
         tw.end_container()?;
@@ -515,7 +518,9 @@ impl Case {
         let mut tw = TLVWriter::new(&mut write_buf);
         tw.start_struct(TagType::Anonymous)?;
         tw.str16_as(TagType::Context(1), |buf| fabric.noc.as_tlv(buf))?;
-        tw.str16_as(TagType::Context(2), |buf| fabric.icac.as_tlv(buf))?;
+        if let Some(icac_cert) = &fabric.icac {
+            tw.str16_as(TagType::Context(2), |buf| icac_cert.as_tlv(buf))?;
+        }
         tw.str8(TagType::Context(3), our_pub_key)?;
         tw.str8(TagType::Context(4), peer_pub_key)?;
         tw.end_container()?;