SVNKit/client: svn+ssh connection w/ Apache MINA sshd, id_ecdsa and id_ed25519 private keys are reported as not valid

When connecting server from SVNKit with SVNSSHAuthentication object like

SVNSSHAuthentication.newInstance(user, keyfile, passphrase, -1, false, url, false)

it returns

SVN authentication error: svn: E170001: File ‘/home/miurahr/.ssh/id_ed25519’ is not valid OpenSSH DSA or RSA private key file
SVN authentication error: svn: E170001: File ‘/home/miurahr/.ssh/id_ecdsa’ is not valid OpenSSH DSA or RSA private key file

A same error is occurred when I use PEM style (old OpenSSH style) private id_rsa private key.

Key-password authentication works fine.

for information:
I’ve added several dependency library to support these EC ciphers,

implementation ‘org.bouncycastle:bcprov-jdk18on:1.72’
implementation ‘org.bouncycastle:bcpg-jdk18on:1.72’
implementation ‘org.bouncycastle:bcpkix-jdk18on:1.72’
implementation ‘net.i2p.crypto:eddsa:0.3.0’

I can operate git+ssh connection with jgit + apache mina sshd and these libraries.

What is wrong?