Puttygen key fingerprint
What is a SSH key fingerprint and how is it generated?
The fingerprint is the MD5 of the Base64-encoded public key.$ ssh-keygen -f foo
Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in foo.
Your public key has been saved in foo.pub.
The key fingerprint is:
65:30:38:96:35:56:4f:64:64:e8:e3:a4:7d:59:3e:19 andrew@localhost
The key's randomart image is:
+-[ RSA 2048]-+
| +*..+* |
| =. +.= |
| . . .o . |
| o+ E |
| S= . + o |
| . o o + |
| . . |
| |
| |
+-+
$ cat foo.pub
| base64 -D | md5
564f6464e8e3a47d593e19
The md5sum 564f6464e8e3a47d593e19 is the fingerprint displayed when
the key is generated, only without the separating colons.However, if you’re dealing with the fingerprints that Amazon shows in the EC2 Key Pairs console,
. If it’s 32 bytes, it’s the standard MD5 SSH public key fingerprint above. But if it’s 40 bytes, it’s actually a fingerprint computed by taking the SHA1 of the private key in PKCS#8 format: