This is pretty old version of Solaris 9 ... is that the problem?
<nova:/># sftp -v budapest
Connecting to budapest...
debug1: SSH args "ssh -oProtocol = 2 -s -oForwardAgent = no -oForwardX11 = no -v budapest sftp"
SSH Version Sun_SSH_1.0.1, protocol versions 1.5/2.0.
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: ssh_connect: getuid 0 geteuid 0 anon 0
debug1: Connecting to budapest [159.127.131.26] port 22.
debug1: Allocated local port 1023.
debug1: Connection established.
debug1: identity file //.ssh/id_rsa type 3
debug1: Bad RSA1 key file //.ssh/id_dsa.
debug1: identity file //.ssh/id_dsa type 3
debug1: Remote protocol version 2.0, remote software version CoreFTP-0.1.2
debug1: no match: CoreFTP-0.1.2
Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-Sun_SSH_1.0.1
debug1: sent kexinit: diffie-hellman-group1-sha1
debug1: sent kexinit: ssh-rsa,ssh-dss
debug1: sent kexinit: aes128-cbc,blowfish-cbc,3des-cbc,rijndael128-cbc
debug1: sent kexinit: aes128-cbc,blowfish-cbc,3des-cbc,rijndael128-cbc
debug1: sent kexinit: hmac-sha1,hmac-md5
debug1: sent kexinit: hmac-sha1,hmac-md5
debug1: sent kexinit: none
debug1: sent kexinit: none
debug1: sent kexinit:
debug1: sent kexinit:
debug1: send KEXINIT
debug1: done
debug1: wait KEXINIT
debug1: got kexinit: diffie-hellman-group1-sha1,diffie-hellman-group14-sha1
debug1: got kexinit: ssh-rsa
debug1: got kexinit: aes128-cbc,3des-cbc,blowfish-cbc,aes192-cbc,aes256-cbc,rijndael128-cbc,rijndael192-cbc,rijndael256-cbc,rijndael-cbc@lysator.liu.se
debug1: got kexinit: aes128-cbc,3des-cbc,blowfish-cbc,aes192-cbc,aes256-cbc,rijndael128-cbc,rijndael192-cbc,rijndael256-cbc,rijndael-cbc@lysator.liu.se
debug1: got kexinit: hmac-sha1,hmac-md5,none
debug1: got kexinit: hmac-sha1,hmac-md5,none
debug1: got kexinit: none,none
debug1: got kexinit: none,none
debug1: got kexinit:
debug1: got kexinit:
debug1: first kex follow: 0
debug1: reserved: 0
debug1: done
debug1: kex: server->client unable to decide common locale
debug1: kex: server->client aes128-cbc hmac-sha1 none
debug1: kex: client->server unable to decide common locale
debug1: kex: client->server aes128-cbc hmac-sha1 none
debug1: Sending SSH2_MSG_KEXDH_INIT.
debug1: bits set: 481/1024
debug1: Wait SSH2_MSG_KEXDH_REPLY.
debug1: Got SSH2_MSG_KEXDH_REPLY.
debug1: Host 'budapest' is known and matches the RSA host key.
debug1: Found key in //.ssh/known_hosts:7
debug1: bits set: 482/1024
debug1: ssh_rsa_verify: signature correct
debug1: Wait SSH2_MSG_NEWKEYS.
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