fix instantiation of key types and key_type_from_name (#34)

* fix instantiation of key types, key_type_from_name and string representation of KeyType
* Added key types and keygen tests

Co-authored-by: Panos <zuboci@yandex.com>

Author: enkore

examples/keygen.py

@@ -0,0 +1,33 @@
+import argparse
+import getpass
+import socket
+import sys
+
+from ssh import key, keytypes
+
+
+parser = argparse.ArgumentParser(description='keygen.py -- like ssh-keygen(1)')
+parser.add_argument('-t', dest='type', help='Key type', default='ed25519', choices=(
+    'rsa', 'ed25519', 'dss'
+))
+parser.add_argument('-f', dest='file', help='Output private key file', required=True)
+parser.add_argument('-b', dest='bits', type=int, default=2048, help='Number of key bits')
+args = parser.parse_args()
+
+key_type = keytypes.key_type_from_name('ssh-' + args.type)
+
+if isinstance(key_type, keytypes.DSSKey):
+    if args.bits != 1024:
+        print('dss keys only support 1024 bits in OpenSSH. Setting -b 1024.', file=sys.stderr)
+    args.bits = 1024
+if isinstance(key_type, keytypes.ED25519Key):
+    args.bits = 0
+
+keypair = key.generate(key_type, args.bits)
+
+keypair.export_privkey_file(args.file)
+pubkey = keypair.export_pubkey_base64().decode()
+pubkey_openssh_format = ' '.join((str(key_type), pubkey, '%s@%s' % (getpass.getuser(), socket.getfqdn())))
+print(pubkey_openssh_format)
+with open(args.file + '.pub', 'w') as fd:
+    print(pubkey_openssh_format, file=fd)

ssh/c_ssh.pxd

@@ -172,7 +172,7 @@ cdef extern from "libssh/libssh.h" nogil:
         SSH_KEYTYPE_DSS,
         SSH_KEYTYPE_RSA,
         SSH_KEYTYPE_RSA1,
-        SSH_KEYTYPE_ECDSA,
+        SSH_KEYTYPE_ECDSA,  # Deprecated
         SSH_KEYTYPE_ED25519,
         SSH_KEYTYPE_DSS_CERT01,
         SSH_KEYTYPE_RSA_CERT01,