I just upgraded to OSX 10.9, and when trying to establish an SSH connection with public key authentication, a prompt appears asking for my SSH key password.

I initially thought that the upgrade caused the keychain to forget some passwords, so I re-entered mine. Apparently, that wasn't the cause, because the prompt kept reappearing.

I first though that I may be using the wrong password, but while the following command:

$ ssh-keygen -vvv -y -f id_rsa >| id_rsa.pub
debug3: Incorrect RSA1 identifier
debug1: key_parse_private_pem: PEM_read_PrivateKey failed
debug1: read PEM private key done: type <unknown>
Enter passphrase:
debug3: Incorrect RSA1 identifier
debug1: key_parse_private_pem: PEM_read_PrivateKey failed
debug1: read PEM private key done: type <unknown>
load failed

...does not work! If I try to use openssl:

$ openssl rsa -in id_rsa -text
Enter pass phrase for id_rsa:
Private-Key: (2048 bit)
modulus:
    00:...

my private key is correctly decrypted and spit all information is printed.

What happened with the upgrade to Mavericks? How can I get my private key back in a usable state?

I just upgraded to OSX 10.9, and when trying to establish an SSH connection with public key authentication, a prompt appears asking for my SSH key password.

I initially thought that the upgrade caused the keychain to forget some passwords, so I re-entered mine. Apparently, that wasn't the cause, because the prompt kept reappearing.

I first though that I may be using the wrong password, but while the following command:

$ ssh-keygen -vvv -y -f id_rsa >| id_rsa.pub
debug3: Incorrect RSA1 identifier
debug1: key_parse_private_pem: PEM_read_PrivateKey failed
debug1: read PEM private key done: type <unknown>
Enter passphrase:
debug3: Incorrect RSA1 identifier
debug1: key_parse_private_pem: PEM_read_PrivateKey failed
debug1: read PEM private key done: type <unknown>
load failed

...does not work! If I try to use openssl:

$ openssl rsa -in id_rsa -text
Enter pass phrase for id_rsa:
Private-Key: (2048 bit)
modulus:
    00:...

my private key is correctly decrypted and all information is printed.

What happened with the upgrade to Mavericks? How can I get my private key back in a usable state?