Vrftjkry

This Question asks about getting the fingerprint of a SSH key while generating the new key with ssh-keygen.

But how does one get determine the fingerprint of an existing public key in a .pub file?

➥ How to get:

• 
  SHA256 hash of an existing key?
  Something like this: SHA256:3VvabBNtRF0XEpYRFnIrhHX6tKZq/vzU+heb3dCYp+0 blah@blah.com
  


• 
  MD5 (is it MD5?) of an existing key?
  Something like this: b6:bf:18:b8:72:83:b7:fb:7d:08:98:72:1f:9f:05:27
  


• 
  Randomart for an existing key?
  Something like this:

+--[ RSA 2048]----+

|       o=.       |

|    o  o++E      |

|   + . Ooo.      |

|    + O B..      |

|     = *S.       |

|      o          |

|                 |

|                 |

|                 |

+-----------------+

Install openssh and openssl packages which contain the commands.

# get the SHA256 and ascii art    

ssh-keygen -l -v -f /path/to/publickey



# get the MD5 for private key

openssl pkey -in /path/to/privatekey -pubout -outform DER | openssl md5 -c



# get the MD5 for public key

openssl pkey -in /path/to/publickey -pubin -pubout -outform DER | openssl md5 -c