diff --git a/ctaocrypt/src/rsa.c b/ctaocrypt/src/rsa.c
index af56f9bac..a0ff196aa 100644
--- a/ctaocrypt/src/rsa.c
+++ b/ctaocrypt/src/rsa.c
@@ -469,6 +469,33 @@ int RsaEncryptSize(RsaKey* key)
 }
 
 
+int RsaFlattenPublicKey(RsaKey* key, byte* e, word32* eSz, byte* n, word32* nSz)
+{
+    int sz, ret;
+
+    if (key == NULL || e == NULL || eSz == NULL || n == NULL || nSz == NULL)
+       return BAD_FUNC_ARG;
+
+    sz = mp_unsigned_bin_size(&key->e);
+    if ((word32)sz > *nSz)
+        return RSA_BUFFER_E;
+    ret = mp_to_unsigned_bin(&key->e, e);
+    if (ret != MP_OKAY)
+        return ret;
+    *eSz = (word32)sz;
+
+    sz = mp_unsigned_bin_size(&key->n);
+    if ((word32)sz > *nSz)
+        return RSA_BUFFER_E;
+    ret = mp_to_unsigned_bin(&key->n, n);
+    if (ret != MP_OKAY)
+        return ret;
+    *nSz = (word32)sz;
+
+    return 0;
+}
+
+
 #ifdef CYASSL_KEY_GEN
 
 static const int USE_BBS = 1;
diff --git a/cyassl/ctaocrypt/rsa.h b/cyassl/ctaocrypt/rsa.h
index 1f94742a8..3fee36207 100644
--- a/cyassl/ctaocrypt/rsa.h
+++ b/cyassl/ctaocrypt/rsa.h
@@ -82,6 +82,8 @@ CYASSL_API int RsaPrivateKeyDecode(const byte* input, word32* inOutIdx, RsaKey*,
                                    word32);
 CYASSL_API int RsaPublicKeyDecode(const byte* input, word32* inOutIdx, RsaKey*,
                                   word32);
+CYASSL_API int RsaFlattenPublicKey(RsaKey*, byte*, word32*, byte*, word32*);
+
 #ifdef CYASSL_KEY_GEN
     CYASSL_API int MakeRsaKey(RsaKey* key, int size, long e, RNG* rng);
     CYASSL_API int RsaKeyToDer(RsaKey*, byte* output, word32 inLen);