(Visual FoxPro) Get Ed25519 Key in Different Formats

Demonstrates how to get/save an Ed25519 private key to different formats.

Converting a private key from one format to another is done by loading in one format and saving/getting in another.

Note: This example requires Chilkat v9.5.0.83 or greater.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loEddsa
LOCAL loPrng
LOCAL loPrivKey
LOCAL lnSuccess
LOCAL lcPkcs1Base64
LOCAL lcPkcs8Base64
LOCAL lcPassword
LOCAL lcPkcs8EncBase64
LOCAL lcEd25519Pem
LOCAL lcJwk
LOCAL loJson
LOCAL lcEd25519_xml
LOCAL loSbPubKeyHex
LOCAL lcPrivKeyHex

* This example assumes the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.EdDSA')
loEddsa = CreateObject('Chilkat.EdDSA')
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Prng')
loPrng = CreateObject('Chilkat.Prng')
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.PrivateKey')
loPrivKey = CreateObject('Chilkat.PrivateKey')

* Generates a new ed25519 key and stores it in privKey.
lnSuccess = loEddsa.GenEd25519Key(loPrng,loPrivKey)
IF (lnSuccess = 0) THEN
    ? loEddsa.LastErrorText
    RELEASE loEddsa
    RELEASE loPrng
    RELEASE loPrivKey
    CANCEL
ENDIF

* ----------------------------------------------------------
* Ed25519 PKCS1 format
* 
* This is the format created by:  openssl genpkey -algorithm X25519 -out xkey.pem
lcPkcs1Base64 = loPrivKey.GetPkcs1ENC("base64")
? lcPkcs1Base64

* Sample output:  MC4CAQAwBQYDK2VuBCIEIB1mwirs+eC6XGbkjPIiZyBwQ7768uSd9v5PHOLFbIXo

* PKCS1 is a binary ASN.1 DER format.  You can examine the contents with two online tools:
* 1) Go to ASN.1 Decoder  and paste the base64 into the online form.
* 2) Or Decode Base64 ASN.1 to XML 

* The PKCS1 ASN.1 format for an Ed25519 key look like this:
*   SEQUENCE
*     INTEGER 0
*     SEQUENCE
*       OBJECT IDENTIFIER 1.3.101.110 curveX25519 (ECDH 25519 key agreement algorithm)
*     OCTET STRING 
*       OCTET STRING (32 byte) 1D66C...

* Save it directly to a file.
lnSuccess = loPrivKey.SavePkcs1File("qa_output/ed25519.key")

* ----------------------------------------------------------
* Ed25519 Unencrypted PKCS8 format
* 
* For ed25519, the ASN.1 output is the same as for PKCS1.
lcPkcs8Base64 = loPrivKey.GetPkcs8ENC("base64")
? lcPkcs8Base64

* PKCS8 is a binary ASN.1 DER format.  You can examine the contents with two online tools:
* 1) Go to ASN.1 Decoder  and paste the base64 into the online form.
* 2) Or Decode Base64 ASN.1 to XML 

* ----------------------------------------------------------
* Ed25519 Encrypted PKCS8 format
* 
* Note: The encrypted output cannot be examined using the above online tools because the ASN.1 is encrypted.
lcPassword = "secret"
lcPkcs8EncBase64 = loPrivKey.GetPkcs8EncryptedENC("base64",lcPassword)
? lcPkcs8EncBase64

* ----------------------------------------------------------
* Ed25519 in PEM format:
* 
lcEd25519Pem = loPrivKey.GetPkcs1Pem()
? lcEd25519Pem

* Sample output:

* -----BEGIN PRIVATE KEY-----
* MC4CAQAwBQYDK2VuBCIEIOKPhbULJagBAi7hbRdn1f4AAzh1RqqCHqCAvau7N6yO
* -----END PRIVATE KEY-----

* ----------------------------------------------------------
* Ed25519 in JWK Format
* 
lcJwk = loPrivKey.GetJwk()

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')
loJson.Load(lcJwk)
loJson.EmitCompact = 0
? loJson.Emit()

* Sample output:
* {
*   "kty": "OKP",
*   "crv": "Ed25519",
*   "x": "SE2Kne5xt51z1eciMH2T2ftDQp96Gl6FhY6zSQujiP0",
*   "d": "O-eRXewadF0sNyB0U9omcnt8Qg2ZmeK3WSXPYgqe570",
*   "use": "sig"
* }

* In the above JWK, x is the public key, y is the private key.
* Both are 32 bytes and are base64-url encoded.

* ----------------------------------------------------------
* Ed25519 in XML Format
* 
lcEd25519_xml = loPrivKey.GetXml()
? lcEd25519_xml

* Sample output:  <Ed25519KeyValue>w4b/gI0zgYKgjtfWLjNfc4issmP7Qap84uesYNgEefP/WoY3jNOhOzgTYsMtOnuyGn3MdA4NZtsUXVNI1NiTlA==</Ed25519KeyValue>

* The base64 content is composed of the concatenation of the 32-byte private key with the 32-byte public key and then base64 encoded.
* In other words:  Base64(privKey || pubKey)

* ----------------------------------------------------------
* Ed25519 in Raw Hex Format
* 
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbPubKeyHex = CreateObject('Chilkat.StringBuilder')
lcPrivKeyHex = loPrivKey.GetRawHex(loSbPubKeyHex)

* We should have a 32-byte private key (a 64 character hex string).
? "private key = " + lcPrivKeyHex

* We should have a 32-byte public key (a 64 character hex string).
? "public key = " + loSbPubKeyHex.GetAsString()

* Sample output:
* key type = ed25519
* size in bits = 256
* private key = d4ee72dbf913584ad5b6d8f1f769f8ad3afe7c28cbf1d4fbe097a88f44755842
* public key = 19bf44096984cdfe8541bac167dc3b96c85086aa30b6b6cb0c5c38ad703166e1

RELEASE loEddsa
RELEASE loPrng
RELEASE loPrivKey
RELEASE loJson
RELEASE loSbPubKeyHex