Supported or Unsupported Keys

This page summarizes key algorithms that are supported/unsupported. Tricks about debugging key-related issues are also documented here.

Feel free to edit this page or fire issues about your suggestions/experiences.

SSH key algorithms

Supported ones

• RSA2048
• ECDSA
• ED25519
• ...

Unsupported ones

• ...

Other tips

Key format

It is recommended to use more compatible PEM format, not the newer OpenSSH format.

Related issues:

• It should also be recommended that people store their keys in the more compatible PEM format, not the newer openssh format (i.e. to not use the -o flag when using ssh-keygen). (Issue205 @savyajha)

• Keys starting with -----BEGIN OPENSSH PRIVATE KEY----- may not be supported. (Issue218 @maximbaz)

• I wasn't able to convert an existing private key, but here is a way of generating a compliant key pair (Issue218 @hreese)

  puttygen -t rsa -b 2048 -O private-openssh -o pass_for_ios.key && \
  puttygen pass_for_ios.key -C "Pass for iOS" -O public-openssh -o pass_for_ios.pub
  

• Both of the following two ways should work: (Issue218 @wpcarro)

  ssh-keygen -t rsa -b 2046 -m PEM -f ./secret.key
  

  puttygen -t rsa -b 2048 -O private-openssh -o pass_for_ios.key && \
  puttygen pass_for_ios.key -C "Pass for iOS" -O public-openssh -o pass_for_ios.pub
  

PGP key algorithms

Supported ones

• RSA4096
• ...

Unsupported ones

• ED25519
• ...