Xbase++

Get Ed25519 Key in Different Formats

See more Ed25519 Examples

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.

Xbase++

LOCAL nSuccess
LOCAL oEddsa
LOCAL oPrng
LOCAL oPrivKey
LOCAL cPkcs1Base64
LOCAL cPkcs8Base64
LOCAL cPassword
LOCAL cPkcs8EncBase64
LOCAL cEd25519Pem
LOCAL cJwk
LOCAL oJson
LOCAL cEd25519_xml
LOCAL oSbPubKeyHex
LOCAL cPrivKeyHex

nSuccess := 0

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

oEddsa := CreateObject("Chilkat.EdDSA")
oPrng := CreateObject("Chilkat.Prng")
oPrivKey := CreateObject("Chilkat.PrivateKey")

//  Generates a new ed25519 key and stores it in privKey.
nSuccess := oEddsa:GenEd25519Key(oPrng, oPrivKey)
IF (nSuccess == 0)
    ? oEddsa:LastErrorText
    oEddsa:destroy()
    oPrng:destroy()
    oPrivKey:destroy()
    RETURN
ENDIF

//  ----------------------------------------------------------
//  Ed25519 PKCS1 format
//  
//  This is the format created by:  openssl genpkey -algorithm X25519 -out xkey.pem
cPkcs1Base64 := oPrivKey:GetPkcs1ENC("base64")
? cPkcs1Base64

//  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.
nSuccess := oPrivKey:SavePkcs1File("qa_output/ed25519.key")

//  ----------------------------------------------------------
//  Ed25519 Unencrypted PKCS8 format
//  
//  For ed25519, the ASN.1 output is the same as for PKCS1.
cPkcs8Base64 := oPrivKey:GetPkcs8ENC("base64")
? cPkcs8Base64

//  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.
cPassword := "secret"
cPkcs8EncBase64 := oPrivKey:GetPkcs8EncryptedENC("base64", cPassword)
? cPkcs8EncBase64

//  ----------------------------------------------------------
//  Ed25519 in PEM format:
//  
cEd25519Pem := oPrivKey:GetPkcs1Pem()
? cEd25519Pem

//  Sample output:

//  -----BEGIN PRIVATE KEY-----
//  MC4CAQAwBQYDK2VuBCIEIOKPhbULJagBAi7hbRdn1f4AAzh1RqqCHqCAvau7N6yO
//  -----END PRIVATE KEY-----

//  ----------------------------------------------------------
//  Ed25519 in JWK Format
//  
cJwk := oPrivKey:GetJwk()

oJson := CreateObject("Chilkat.JsonObject")
oJson:Load(cJwk)
oJson:EmitCompact := 0
? oJson: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
//  
cEd25519_xml := oPrivKey:GetXml()
? cEd25519_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
//  
oSbPubKeyHex := CreateObject("Chilkat.StringBuilder")
cPrivKeyHex := oPrivKey:GetRawHex(oSbPubKeyHex)

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

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

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

oEddsa:destroy()
oPrng:destroy()
oPrivKey:destroy()
oJson:destroy()
oSbPubKeyHex:destroy()