diff --git a/src/chat/chat_channel.c b/src/chat/chat_channel.c
index 0c0bec18..a67d8462 100644
--- a/src/chat/chat_channel.c
+++ b/src/chat/chat_channel.c
@@ -32,6 +32,7 @@
 #include <openssl/sha.h>
 #include <openssl/evp.h>
 #include <openssl/rand.h>
+#include <openssl/crypto.h>
 #include <errno.h>
 #include <stdlib.h>
 
@@ -191,6 +192,7 @@ void chat_core_create_channel_trampoline(void* arg) {
     struct chat_channel_create* req = (struct chat_channel_create*)arg;
     if (!req) return;
     chat_core_create_channel(req->inst, req);
+    OPENSSL_cleanse(req, sizeof(*req));
     u_free(req);
 }
 
diff --git a/src/chat/chat_sync.c b/src/chat/chat_sync.c
index e60a7f3e..a1bd6f5e 100644
--- a/src/chat/chat_sync.c
+++ b/src/chat/chat_sync.c
@@ -1220,13 +1220,9 @@ static void cs_handle_join_info_resp(struct chat_sync* cs, uint64_t peer,
                 (unsigned long long)ch_x_prefix, (unsigned long long)ch_ed_prefix, name, (unsigned long long)c_node_id);
 
     /* verify channel signature */
-    uint8_t vmsg[1024]; size_t vlen = 0;
-    vlen += snprintf((char*)vmsg + vlen, sizeof(vmsg) - vlen, "%s", ch_id) + 1;
-    vlen += snprintf((char*)vmsg + vlen, sizeof(vmsg) - vlen, "%s", name) + 1;
-    memcpy(vmsg + vlen, &owner, 8); vlen += 8;
-    memcpy(vmsg + vlen, ch_x25519, 32); vlen += 32;
-    memcpy(vmsg + vlen, ch_ed, 32); vlen += 32;
-    if (cs_ed25519_verify(ch_ed, vmsg, vlen, ch_sig) != 0) {
+    uint8_t vmsg[CHAT_CHANNEL_DESCRIPTION_MAX];
+    int vlen = chat_channel_description_data(ch_id, name, owner, ch_x25519, ch_ed, vmsg, sizeof(vmsg));
+    if (vlen < 0 || cs_ed25519_verify(ch_ed, vmsg, (size_t)vlen, ch_sig) != 0) {
         DEBUG_ERROR(DEBUG_CATEGORY_MEMBER_SYNC, "%s: JOIN_INFO_RESP invalid ch_sig ch=%s", CS_ID, ch_id);
         return;
     }
@@ -1521,13 +1517,9 @@ static void cs_handle_channel_invite(struct chat_sync* cs, uint64_t peer,
     memcpy(&join_key, p, 8); p += 8;
 
     /* Verify channel signature */
-    uint8_t vmsg[1024]; size_t vlen = 0;
-    vlen += snprintf((char*)vmsg + vlen, sizeof(vmsg) - vlen, "%s", ch_id) + 1;
-    vlen += snprintf((char*)vmsg + vlen, sizeof(vmsg) - vlen, "%s", name) + 1;
-    memcpy(vmsg + vlen, &owner, 8); vlen += 8;
-    memcpy(vmsg + vlen, x25519, 32); vlen += 32;
-    memcpy(vmsg + vlen, ed_pub, 32); vlen += 32;
-    if (cs_ed25519_verify(ed_pub, vmsg, vlen, ch_sig) != 0) {
+    uint8_t vmsg[CHAT_CHANNEL_DESCRIPTION_MAX];
+    int vlen = chat_channel_description_data(ch_id, name, owner, x25519, ed_pub, vmsg, sizeof(vmsg));
+    if (vlen < 0 || cs_ed25519_verify(ed_pub, vmsg, (size_t)vlen, ch_sig) != 0) {
         DEBUG_ERROR(DEBUG_CATEGORY_MEMBER_SYNC, "%s: CHANNEL_INVITE invalid ch_sig ch=%s from=%016llx", CS_ID, ch_id, (unsigned long long)peer);
         return;
     }