diff --git a/wolfcrypt/src/md5.c b/wolfcrypt/src/md5.c
index 342aea466..fcaa73965 100755
--- a/wolfcrypt/src/md5.c
+++ b/wolfcrypt/src/md5.c
@@ -447,6 +447,9 @@ int wc_Md5Final(Md5* md5, byte* hash)
 
 int wc_InitMd5(Md5* md5)
 {
+    if (md5 == NULL) {
+        return BAD_FUNC_ARG;
+    }
     return wc_InitMd5_ex(md5, NULL, INVALID_DEVID);
 }
 
diff --git a/wolfcrypt/src/sha.c b/wolfcrypt/src/sha.c
index f98cb7272..e35c5ba7d 100755
--- a/wolfcrypt/src/sha.c
+++ b/wolfcrypt/src/sha.c
@@ -42,6 +42,9 @@
 	}
     int wc_InitSha_ex(Sha* sha, void* heap, int devId)
     {
+        if (sha == NULL) {
+            return BAD_FUNC_ARG;
+        }
         (void)heap;
         (void)devId;
         return InitSha_fips(sha);
@@ -543,6 +546,9 @@ int wc_ShaFinal(Sha* sha, byte* hash)
 
 int wc_InitSha(Sha* sha)
 {
+    if (sha == NULL) {
+        return BAD_FUNC_ARG;
+    }
     return wc_InitSha_ex(sha, NULL, INVALID_DEVID);
 }
 
diff --git a/wolfcrypt/src/sha256.c b/wolfcrypt/src/sha256.c
index 40fc57e53..40eb0f421 100755
--- a/wolfcrypt/src/sha256.c
+++ b/wolfcrypt/src/sha256.c
@@ -45,6 +45,9 @@
     }
     int wc_InitSha256_ex(Sha256* sha, void* heap, int devId)
     {
+        if (sha == NULL) {
+            return BAD_FUNC_ARG;
+        }
         (void)heap;
         (void)devId;
         return InitSha256_fips(sha);
@@ -562,9 +565,14 @@ static int InitSha256(Sha256* sha256)
 
     static INLINE int Sha256Final(Sha256* sha256)
     {
+
         int ret;
         byte* local = (byte*)sha256->buffer;
 
+        if (sha256 == NULL) {
+            return BAD_FUNC_ARG;
+        }
+
         SAVE_XMM_YMM; /* for Intel AVX */
 
         AddLength(sha256, sha256->buffLen);  /* before adding pads */
@@ -1918,6 +1926,9 @@ static int Transform_AVX2(Sha256* sha256)
 
 int wc_InitSha256(Sha256* sha256)
 {
+    if (sha256 == NULL) {
+        return BAD_FUNC_ARG;
+    }
     return wc_InitSha256_ex(sha256, NULL, INVALID_DEVID);
 }
 
diff --git a/wolfcrypt/src/sha512.c b/wolfcrypt/src/sha512.c
index 9d9233605..8b560d04c 100755
--- a/wolfcrypt/src/sha512.c
+++ b/wolfcrypt/src/sha512.c
@@ -44,6 +44,9 @@
     }
     int wc_InitSha512_ex(Sha512* sha, void* heap, int devId)
     {
+        if (sha == NULL) {
+            return BAD_FUNC_ARG;
+        }
         (void)heap;
         (void)devId;
         return InitSha512_fips(sha);
@@ -537,7 +540,9 @@ static INLINE void AddLength(Sha512* sha512, word32 len)
 static INLINE int Sha512Update(Sha512* sha512, const byte* data, word32 len)
 {
     int ret = 0;
-
+    if (sha512 == NULL || (data == NULL && len > 0)) {
+        return BAD_FUNC_ARG;
+    }
     /* do block size increments */
     byte* local = (byte*)sha512->buffer;
 
@@ -598,6 +603,10 @@ static INLINE int Sha512Final(Sha512* sha512)
     byte* local = (byte*)sha512->buffer;
     int ret;
 
+    if (sha512 == NULL) {
+        return BAD_FUNC_ARG;
+    }
+
     SAVE_XMM_YMM ; /* for Intel AVX */
     AddLength(sha512, sha512->buffLen);               /* before adding pads */