address review feedback

doc/dox_comments/header_files/asn_public.h

@@ -1578,6 +1578,21 @@ int wc_EccPublicKeyToDer_ex(ecc_key* key, byte* output,
     index is set to last position parsed of input buffer.
     \param key Pointer to curve25519_key structure to store decoded key
     \param inSz Size of input DER buffer
+
+    \sa wc_Curve25519KeyDecode
+    \sa wc_Curve25519PublicKeyDecode
+
+    _Example_
+    \code
+    byte der[] = { // DER encoded key };
+    word32 idx = 0;
+    curve25519_key key;
+    wc_curve25519_init(&key);
+
+    if (wc_Curve25519PrivateKeyDecode(der, &idx, &key, sizeof(der)) != 0) {
+        // Error decoding private key
+    }
+    \endcode
 */
 int wc_Curve25519PrivateKeyDecode(const byte* input, word32* inOutIdx,
                                   curve25519_key* key, word32 inSz);
@@ -1602,6 +1617,20 @@ int wc_Curve25519PrivateKeyDecode(const byte* input, word32* inOutIdx,
     index is set to last position parsed of input buffer.
     \param key Pointer to curve25519_key structure to store decoded key
     \param inSz Size of input DER buffer
+
+    \sa wc_Curve25519KeyDecode
+    \sa wc_Curve25519PrivateKeyDecode
+
+    _Example_
+    \code
+    byte der[] = { // DER encoded key };
+    word32 idx = 0;
+    curve25519_key key;
+    wc_curve25519_init(&key);
+    if (wc_Curve25519PublicKeyDecode(der, &idx, &key, sizeof(der)) != 0) {
+        // Error decoding public key
+    }
+    \endcode
 */
 int wc_Curve25519PublicKeyDecode(const byte* input, word32* inOutIdx,
                                  curve25519_key* key, word32 inSz);
@@ -1626,6 +1655,20 @@ int wc_Curve25519PublicKeyDecode(const byte* input, word32* inOutIdx,
     index is set to last position parsed of input buffer.
     \param key Pointer to curve25519_key structure to store decoded key
     \param inSz Size of input DER buffer
+
+    \sa wc_Curve25519PrivateKeyDecode
+    \sa wc_Curve25519PublicKeyDecode
+
+    _Example_
+    \code
+    byte der[] = { // DER encoded key };
+    word32 idx = 0;
+    curve25519_key key;
+    wc_curve25519_init(&key);
+    if (wc_Curve25519KeyDecode(der, &idx, &key, sizeof(der)) != 0) {
+        // Error decoding key
+    }
+    \endcode
 */
 int wc_Curve25519KeyDecode(const byte* input, word32* inOutIdx,
                            curve25519_key* key, word32 inSz);
@@ -1645,6 +1688,19 @@ int wc_Curve25519KeyDecode(const byte* input, word32* inOutIdx,
     encode
     \param output Buffer to hold DER encoding
     \param inLen Size of output buffer
+
+    \sa wc_Curve25519KeyToDer
+    \sa wc_Curve25519PublicKeyToDer
+
+    _Example_
+    \code
+    curve25519_key key;
+    wc_curve25519_init(&key);
+    ...
+    int derSz = 128; // Some appropriate size for output DER
+    byte der[derSz];
+    wc_Curve25519PrivateKeyToDer(&key, der, derSz);
+    \endcode
 */
 int wc_Curve25519PrivateKeyToDer(curve25519_key* key, byte* output,
                                  word32 inLen);
@@ -1664,7 +1720,20 @@ int wc_Curve25519PrivateKeyToDer(curve25519_key* key, byte* output,
     encode
     \param output Buffer to hold DER encoding
     \param inLen Size of output buffer
-    \param withAlg Whether to include algorithm identifier
+    \param withAlg Whether to include algorithm identifier in the DER encoding
+
+    \sa wc_Curve25519KeyToDer
+    \sa wc_Curve25519PrivateKeyToDer
+
+    _Example_
+    \code
+    curve25519_key key;
+    wc_curve25519_init(&key);
+    ...
+    int derSz = 128; // Some appropriate size for output DER
+    byte der[derSz];
+    wc_Curve25519PublicKeyToDer(&key, der, derSz, 1);
+    \endcode
 */
 int wc_Curve25519PublicKeyToDer(curve25519_key* key, byte* output, word32 inLen,
                                 int withAlg);
@@ -1683,7 +1752,20 @@ int wc_Curve25519PublicKeyToDer(curve25519_key* key, byte* output, word32 inLen,
     \param key Pointer to curve25519_key structure containing key to encode
     \param output Buffer to hold DER encoding
     \param inLen Size of output buffer
-    \param withAlg Whether to include algorithm identifier
+    \param withAlg Whether to include algorithm identifier in the DER encoding
+
+    \sa wc_Curve25519PrivateKeyToDer
+    \sa wc_Curve25519PublicKeyToDer
+
+    _Example_
+    \code
+    curve25519_key key;
+    wc_curve25519_init(&key);
+    ...
+    int derSz = 128; // Some appropriate size for output DER
+    byte der[derSz];
+    wc_Curve25519KeyToDer(&key, der, derSz, 1);
+    \endcode
 */
 int wc_Curve25519KeyToDer(curve25519_key* key, byte* output, word32 inLen,
                           int withAlg);

wolfcrypt/src/asn.c

@@ -35670,9 +35670,9 @@ int wc_Curve25519KeyDecode(const byte* input, word32* inOutIdx,
 {
     int ret;
     byte privKey[CURVE25519_KEYSIZE];
-    byte pubKey[CURVE25519_KEYSIZE];
+    byte pubKey[CURVE25519_PUB_KEY_SIZE];
     word32 privKeyLen = CURVE25519_KEYSIZE;
-    word32 pubKeyLen = CURVE25519_KEYSIZE;
+    word32 pubKeyLen = CURVE25519_PUB_KEY_SIZE;
 
     /* sanity check */
     if (input == NULL || inOutIdx == NULL || key == NULL || inSz == 0) {
@@ -35925,9 +35925,9 @@ int wc_Curve25519KeyToDer(curve25519_key* key, byte* output, word32 inLen, int w
 {
     int ret;
     byte privKey[CURVE25519_KEYSIZE];
-    byte pubKey[CURVE25519_KEYSIZE];
+    byte pubKey[CURVE25519_PUB_KEY_SIZE];
     word32 privKeyLen = CURVE25519_KEYSIZE;
-    word32 pubKeyLen = CURVE25519_KEYSIZE;
+    word32 pubKeyLen = CURVE25519_PUB_KEY_SIZE;
 
     if (key == NULL) {
         return BAD_FUNC_ARG;

wolfcrypt/test/test.c

@@ -35098,8 +35098,7 @@ static wc_test_ret_t curve255519_der_test(void)
         ret = WC_TEST_RET_ENC_NC;
     }
 
-    /* Test decode/encode of a key file containing both public and private
+    /* Test decode/encode key data containing both public and private fields */
-     * fields */
     if (ret == 0) {
         XMEMSET(&key, 0 , sizeof(key));