Method Eddsa

java/lib/src/main/java/io/github/ccxt/base/Crypto.java:563–593

(Object request, Object secret, Object alg)

    // ====================================================

    public static Object Eddsa(Object request, Object secret, Object alg) {
        try {
            byte[] msg = (request instanceof String) ? toUtf8(request) : (byte[]) request;
            byte[] seed = extractEd25519Seed(secret);

            // Build PKCS#8 DER encoding for the 32-byte Ed25519 seed.
            // PKCS#8 wraps the raw seed in ASN.1: SEQUENCE { SEQUENCE { OID 1.3.101.112 }, OCTET STRING { OCTET STRING { seed } } }
            byte[] pkcs8 = new byte[48];
            byte[] prefix = {
                0x30, 0x2e,                   // SEQUENCE (46 bytes)
                0x02, 0x01, 0x00,             // INTEGER 0 (version)
                0x30, 0x05,                   // SEQUENCE (5 bytes)
                0x06, 0x03, 0x2b, 0x65, 0x70, // OID 1.3.101.112 (Ed25519)
                0x04, 0x22,                   // OCTET STRING (34 bytes)
                0x04, 0x20                    // OCTET STRING (32 bytes) - the seed
            };
            System.arraycopy(prefix, 0, pkcs8, 0, prefix.length);
            System.arraycopy(seed, 0, pkcs8, prefix.length, 32);

            java.security.KeyFactory kf = java.security.KeyFactory.getInstance("Ed25519");
            java.security.PrivateKey privateKey = kf.generatePrivate(new java.security.spec.PKCS8EncodedKeySpec(pkcs8));

            java.security.Signature sig = java.security.Signature.getInstance("Ed25519");
            sig.initSign(privateKey);
            sig.update(msg);
            byte[] signature = sig.sign();
            return Base64.getEncoder().encodeToString(signature);
        } catch (Exception e) {
            throw new RuntimeException("Ed25519 signing failed: " + e.getMessage(), e);
        }
    }

    /**
     * Extract the 32-byte Ed25519 seed from various secret formats: