diff --git a/wolfcrypt/src/sp_x86_64.c b/wolfcrypt/src/sp_x86_64.c
index 171ef6ada..91cd7c421 100644
--- a/wolfcrypt/src/sp_x86_64.c
+++ b/wolfcrypt/src/sp_x86_64.c
@@ -1956,10 +1956,17 @@ int sp_ModExp_2048(const mp_int* base, const mp_int* exp, const mp_int* mod,
     mp_int* res)
 {
     int err = MP_OKAY;
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    sp_digit *b = NULL;
+    sp_digit *e = NULL;
+    sp_digit *m = NULL;
+    sp_digit* r;
+#else
     sp_digit b[64];
     sp_digit e[32];
     sp_digit m[32];
     sp_digit* r = b;
+#endif
 #ifdef HAVE_INTEL_AVX2
     word32 cpuid_flags = cpuid_get_flags();
 #endif
@@ -1973,6 +1980,19 @@ int sp_ModExp_2048(const mp_int* base, const mp_int* exp, const mp_int* mod,
         err = MP_VAL;
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (err == MP_OKAY) {
+        if (((b = (sp_digit *)XMALLOC(64 * sizeof(*b), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((e = (sp_digit *)XMALLOC(32 * sizeof(*e), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((m = (sp_digit *)XMALLOC(32 * sizeof(*m), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL))
+        {
+            err = MEMORY_E;
+        } else {
+            r = b;
+        }
+    }
+#endif
+
     if (err == MP_OKAY) {
         sp_2048_from_mp(b, 32, base);
         sp_2048_from_mp(e, 32, exp);
@@ -1990,7 +2010,18 @@ int sp_ModExp_2048(const mp_int* base, const mp_int* exp, const mp_int* mod,
         err = sp_2048_to_mp(r, res);
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (b != NULL)
+        XFREE(b, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    if (e != NULL) {
+        XMEMSET(e, 0, 32);
+        XFREE(e, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    }
+    if (m != NULL)
+        XFREE(m, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+#else
     XMEMSET(e, 0, sizeof(e));
+#endif
 
     return err;
 }
@@ -2266,10 +2297,17 @@ int sp_DhExp_2048(const mp_int* base, const byte* exp, word32 expLen,
     const mp_int* mod, byte* out, word32* outLen)
 {
     int err = MP_OKAY;
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    sp_digit *b = NULL;
+    sp_digit *e = NULL;
+    sp_digit *m = NULL;
+    sp_digit* r;
+#else
     sp_digit b[64];
     sp_digit e[32];
     sp_digit m[32];
     sp_digit* r = b;
+#endif
     word32 i;
 #ifdef HAVE_INTEL_AVX2
     word32 cpuid_flags = cpuid_get_flags();
@@ -2283,6 +2321,19 @@ int sp_DhExp_2048(const mp_int* base, const byte* exp, word32 expLen,
         err = MP_VAL;
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (err == MP_OKAY) {
+        if (((b = (sp_digit *)XMALLOC(64 * sizeof(*b), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((e = (sp_digit *)XMALLOC(32 * sizeof(*e), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((m = (sp_digit *)XMALLOC(32 * sizeof(*m), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL))
+        {
+            err = MEMORY_E;
+        } else {
+            r = b;
+        }
+    }
+#endif
+
     if (err == MP_OKAY) {
         sp_2048_from_mp(b, 32, base);
         sp_2048_from_bin(e, 32, exp, expLen);
@@ -2319,7 +2370,18 @@ int sp_DhExp_2048(const mp_int* base, const byte* exp, word32 expLen,
         XMEMMOVE(out, out + i, *outLen);
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (b != NULL)
+        XFREE(b, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    if (e != NULL) {
+        XMEMSET(e, 0, 32);
+        XFREE(e, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    }
+    if (m != NULL)
+        XFREE(m, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+#else
     XMEMSET(e, 0, sizeof(e));
+#endif
 
     return err;
 }
@@ -2337,10 +2399,17 @@ int sp_ModExp_1024(const mp_int* base, const mp_int* exp, const mp_int* mod,
     mp_int* res)
 {
     int err = MP_OKAY;
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    sp_digit *b = NULL;
+    sp_digit *e = NULL;
+    sp_digit *m = NULL;
+    sp_digit* r;
+#else
     sp_digit b[32];
     sp_digit e[16];
     sp_digit m[16];
     sp_digit* r = b;
+#endif
 #ifdef HAVE_INTEL_AVX2
     word32 cpuid_flags = cpuid_get_flags();
 #endif
@@ -2354,6 +2423,19 @@ int sp_ModExp_1024(const mp_int* base, const mp_int* exp, const mp_int* mod,
         err = MP_VAL;
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (err == MP_OKAY) {
+        if (((b = (sp_digit *)XMALLOC(32 * sizeof(*b), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((e = (sp_digit *)XMALLOC(16 * sizeof(*e), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((m = (sp_digit *)XMALLOC(16 * sizeof(*m), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL))
+        {
+            err = MEMORY_E;
+        } else {
+            r = b;
+        }
+    }
+#endif
+
     if (err == MP_OKAY) {
         sp_2048_from_mp(b, 16, base);
         sp_2048_from_mp(e, 16, exp);
@@ -2372,7 +2454,18 @@ int sp_ModExp_1024(const mp_int* base, const mp_int* exp, const mp_int* mod,
         err = sp_2048_to_mp(r, res);
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (b != NULL)
+        XFREE(b, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    if (e != NULL) {
+        XMEMSET(e, 0, 16);
+        XFREE(e, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    }
+    if (m != NULL)
+        XFREE(m, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+#else
     XMEMSET(e, 0, sizeof(e));
+#endif
 
     return err;
 }
@@ -4287,10 +4380,17 @@ int sp_ModExp_3072(const mp_int* base, const mp_int* exp, const mp_int* mod,
     mp_int* res)
 {
     int err = MP_OKAY;
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    sp_digit *b = NULL;
+    sp_digit *e = NULL;
+    sp_digit *m = NULL;
+    sp_digit* r;
+#else
     sp_digit b[96];
     sp_digit e[48];
     sp_digit m[48];
     sp_digit* r = b;
+#endif
 #ifdef HAVE_INTEL_AVX2
     word32 cpuid_flags = cpuid_get_flags();
 #endif
@@ -4304,6 +4404,19 @@ int sp_ModExp_3072(const mp_int* base, const mp_int* exp, const mp_int* mod,
         err = MP_VAL;
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (err == MP_OKAY) {
+        if (((b = (sp_digit *)XMALLOC(96 * sizeof(*b), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((e = (sp_digit *)XMALLOC(48 * sizeof(*e), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((m = (sp_digit *)XMALLOC(48 * sizeof(*m), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL))
+        {
+            err = MEMORY_E;
+        } else {
+            r = b;
+        }
+    }
+#endif
+
     if (err == MP_OKAY) {
         sp_3072_from_mp(b, 48, base);
         sp_3072_from_mp(e, 48, exp);
@@ -4321,7 +4434,18 @@ int sp_ModExp_3072(const mp_int* base, const mp_int* exp, const mp_int* mod,
         err = sp_3072_to_mp(r, res);
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (b != NULL)
+        XFREE(b, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    if (e != NULL) {
+        XMEMSET(e, 0, 48);
+        XFREE(e, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    }
+    if (m != NULL)
+        XFREE(m, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+#else
     XMEMSET(e, 0, sizeof(e));
+#endif
 
     return err;
 }
@@ -4597,10 +4721,17 @@ int sp_DhExp_3072(const mp_int* base, const byte* exp, word32 expLen,
     const mp_int* mod, byte* out, word32* outLen)
 {
     int err = MP_OKAY;
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    sp_digit *b = NULL;
+    sp_digit *e = NULL;
+    sp_digit *m = NULL;
+    sp_digit* r;
+#else
     sp_digit b[96];
     sp_digit e[48];
     sp_digit m[48];
     sp_digit* r = b;
+#endif
     word32 i;
 #ifdef HAVE_INTEL_AVX2
     word32 cpuid_flags = cpuid_get_flags();
@@ -4614,6 +4745,19 @@ int sp_DhExp_3072(const mp_int* base, const byte* exp, word32 expLen,
         err = MP_VAL;
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (err == MP_OKAY) {
+        if (((b = (sp_digit *)XMALLOC(96 * sizeof(*b), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((e = (sp_digit *)XMALLOC(48 * sizeof(*e), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((m = (sp_digit *)XMALLOC(48 * sizeof(*m), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL))
+        {
+            err = MEMORY_E;
+        } else {
+            r = b;
+        }
+    }
+#endif
+
     if (err == MP_OKAY) {
         sp_3072_from_mp(b, 48, base);
         sp_3072_from_bin(e, 48, exp, expLen);
@@ -4650,7 +4794,18 @@ int sp_DhExp_3072(const mp_int* base, const byte* exp, word32 expLen,
         XMEMMOVE(out, out + i, *outLen);
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (b != NULL)
+        XFREE(b, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    if (e != NULL) {
+        XMEMSET(e, 0, 48);
+        XFREE(e, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    }
+    if (m != NULL)
+        XFREE(m, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+#else
     XMEMSET(e, 0, sizeof(e));
+#endif
 
     return err;
 }
@@ -4668,10 +4823,17 @@ int sp_ModExp_1536(const mp_int* base, const mp_int* exp, const mp_int* mod,
     mp_int* res)
 {
     int err = MP_OKAY;
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    sp_digit *b = NULL;
+    sp_digit *e = NULL;
+    sp_digit *m = NULL;
+    sp_digit* r;
+#else
     sp_digit b[48];
     sp_digit e[24];
     sp_digit m[24];
     sp_digit* r = b;
+#endif
 #ifdef HAVE_INTEL_AVX2
     word32 cpuid_flags = cpuid_get_flags();
 #endif
@@ -4685,6 +4847,19 @@ int sp_ModExp_1536(const mp_int* base, const mp_int* exp, const mp_int* mod,
         err = MP_VAL;
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (err == MP_OKAY) {
+        if (((b = (sp_digit *)XMALLOC(48 * sizeof(*b), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((e = (sp_digit *)XMALLOC(24 * sizeof(*e), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
+            ((m = (sp_digit *)XMALLOC(24 * sizeof(*m), NULL, DYNAMIC_TYPE_TMP_BUFFER)) == NULL))
+        {
+            err = MEMORY_E;
+        } else {
+            r = b;
+        }
+    }
+#endif
+
     if (err == MP_OKAY) {
         sp_3072_from_mp(b, 24, base);
         sp_3072_from_mp(e, 24, exp);
@@ -4703,7 +4878,18 @@ int sp_ModExp_1536(const mp_int* base, const mp_int* exp, const mp_int* mod,
         err = sp_3072_to_mp(r, res);
     }
 
+#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_SP_NO_MALLOC)
+    if (b != NULL)
+        XFREE(b, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    if (e != NULL) {
+        XMEMSET(e, 0, 24);
+        XFREE(e, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    }
+    if (m != NULL)
+        XFREE(m, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+#else
     XMEMSET(e, 0, sizeof(e));
+#endif
 
     return err;
 }