From 9fef016106ea8574bf8b84b1c3383ac169ac284c Mon Sep 17 00:00:00 2001
From: Kareem <kareem@wolfssl.com>
Date: Wed, 22 Apr 2026 15:47:39 -0700
Subject: [PATCH 1/2] Fix W560 "possible truncation at implicit conversion to
 type unsigned char" warnings raised by Tasking compiler.

---
 src/tls13.c                |  2 +-
 src/wolfio.c               |  6 +++++-
 wolfcrypt/src/fe_low_mem.c | 18 +++++++++---------
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/src/tls13.c b/src/tls13.c
index 824ad08b696..a3a6607e5b1 100644
--- a/src/tls13.c
+++ b/src/tls13.c
@@ -8577,7 +8577,7 @@ static WC_INLINE int DecodeTls13SigAlg(byte* input, byte* hashAlgo,
             break;
     #endif
         case NEW_SA_MAJOR:
-            *hashAlgo = GetNewSAHashAlgo(input[1]);
+            *hashAlgo = (byte)GetNewSAHashAlgo(input[1]);
 
             /* PSS encryption: 0x080[4-6] */
             if (input[1] >= RSA_PSS_RSAE_SHA256_MINOR &&
diff --git a/src/wolfio.c b/src/wolfio.c
index c6ffe7da11b..22a4e6ee6b2 100644
--- a/src/wolfio.c
+++ b/src/wolfio.c
@@ -3286,7 +3286,11 @@ int LwIPNativeSend(WOLFSSL* ssl, char* buf, int sz, void* ctx)
     err_t ret;
     WOLFSSL_LWIP_NATIVE_STATE* nlwip = (WOLFSSL_LWIP_NATIVE_STATE*)ctx;
 
-    ret = tcp_write(nlwip->pcb, buf, sz, TCP_WRITE_FLAG_COPY);
+    if (sz > UINT16_MAX || sz < 0) {
+        return BAD_FUNC_ARG;
+    }
+
+    ret = tcp_write(nlwip->pcb, buf, (u16_t)sz, TCP_WRITE_FLAG_COPY);
     if (ret != ERR_OK) {
         sz = WOLFSSL_FATAL_ERROR;
     }
diff --git a/wolfcrypt/src/fe_low_mem.c b/wolfcrypt/src/fe_low_mem.c
index f1c5eddd340..61b88769043 100644
--- a/wolfcrypt/src/fe_low_mem.c
+++ b/wolfcrypt/src/fe_low_mem.c
@@ -546,7 +546,7 @@ void fe_load(byte *x, word32 c)
     word32 i;
 
     for (i = 0; i < sizeof(c); i++) {
-        x[i] = c;
+        x[i] = (byte)c;
         c >>= 8;
     }
 
@@ -636,7 +636,7 @@ void lm_sub(byte* r, const byte* a, const byte* b)
     c = 218;
     for (i = 0; i + 1 < F25519_SIZE; i++) {
         c += 65280 + ((word32)a[i]) - ((word32)b[i]);
-        r[i] = c;
+        r[i] = (byte)c;
         c >>= 8;
     }
 
@@ -646,7 +646,7 @@ void lm_sub(byte* r, const byte* a, const byte* b)
 
     for (i = 0; i < F25519_SIZE; i++) {
         c += r[i];
-        r[i] = c;
+        r[i] = (byte)c;
         c >>= 8;
     }
 }
@@ -661,7 +661,7 @@ void lm_neg(byte* r, const byte* a)
     c = 218;
     for (i = 0; i + 1 < F25519_SIZE; i++) {
         c += 65280 - ((word32)a[i]);
-        r[i] = c;
+        r[i] = (byte)c;
         c >>= 8;
     }
 
@@ -671,7 +671,7 @@ void lm_neg(byte* r, const byte* a)
 
     for (i = 0; i < F25519_SIZE; i++) {
         c += r[i];
-        r[i] = c;
+        r[i] = (byte)c;
         c >>= 8;
     }
 }
@@ -693,7 +693,7 @@ void fe_mul__distinct(byte *r, const byte *a, const byte *b)
             c += ((word32)a[j]) *
                 ((word32)b[i + F25519_SIZE - j]) * 38;
 
-        r[i] = c;
+        r[i] = (byte)c;
     }
 
     r[31] &= 127;
@@ -701,7 +701,7 @@ void fe_mul__distinct(byte *r, const byte *a, const byte *b)
 
     for (i = 0; i < F25519_SIZE; i++) {
         c += r[i];
-        r[i] = c;
+        r[i] = (byte)c;
         c >>= 8;
     }
 }
@@ -724,7 +724,7 @@ void fe_mul_c(byte *r, const byte *a, word32 b)
     for (i = 0; i < F25519_SIZE; i++) {
         c >>= 8;
         c += b * ((word32)a[i]);
-        r[i] = c;
+        r[i] = (byte)c;
     }
 
     r[31] &= 127;
@@ -733,7 +733,7 @@ void fe_mul_c(byte *r, const byte *a, word32 b)
 
     for (i = 0; i < F25519_SIZE; i++) {
         c += r[i];
-        r[i] = c;
+        r[i] = (byte)c;
         c >>= 8;
     }
 }

From c69d9693f017e6468fb5a47ef760e1e75632752c Mon Sep 17 00:00:00 2001
From: Kareem <kareem@wolfssl.com>
Date: Wed, 22 Apr 2026 16:33:07 -0700
Subject: [PATCH 2/2] Fix code review feedback and test failure.

---
 src/tls13.c  | 5 ++++-
 src/wolfio.c | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/tls13.c b/src/tls13.c
index a3a6607e5b1..8b49cc33bcf 100644
--- a/src/tls13.c
+++ b/src/tls13.c
@@ -8577,7 +8577,10 @@ static WC_INLINE int DecodeTls13SigAlg(byte* input, byte* hashAlgo,
             break;
     #endif
         case NEW_SA_MAJOR:
-            *hashAlgo = (byte)GetNewSAHashAlgo(input[1]);
+        {
+            enum wc_MACAlgorithm mac = GetNewSAHashAlgo(input[1]);
+            *hashAlgo = (byte)mac;
+        }
 
             /* PSS encryption: 0x080[4-6] */
             if (input[1] >= RSA_PSS_RSAE_SHA256_MINOR &&
diff --git a/src/wolfio.c b/src/wolfio.c
index 22a4e6ee6b2..e438e8fe7f5 100644
--- a/src/wolfio.c
+++ b/src/wolfio.c
@@ -3286,7 +3286,7 @@ int LwIPNativeSend(WOLFSSL* ssl, char* buf, int sz, void* ctx)
     err_t ret;
     WOLFSSL_LWIP_NATIVE_STATE* nlwip = (WOLFSSL_LWIP_NATIVE_STATE*)ctx;
 
-    if (sz > UINT16_MAX || sz < 0) {
+    if (sz < 0 || sz > (int)WOLFSSL_MAX_16BIT) {
         return BAD_FUNC_ARG;
     }