How to find SFTP server fingerprints?
Finding the SFTP public host key fingerprints after accessing your transfer site.
The easiest way to get an SFTP fingerprint is to connect to a server for the first time, and there will be a warning that this is a new host, and the fingerprint will be presented. For example, connect to transfer6.silverpop.com for the first time and you will get this type of warning:
$ sftp transfer6.silverpop.com
The authenticity of host 'transfer6.silverpop.com (108.168.255.75)' can't be established.
RSA key fingerprint is a0:92:74:7e:43:c6:59:60:70:c5:17:72:24:77:31:db.
Are you sure you want to continue connecting (yes/no)?
The fingerprint is presented in this example in "MD5" format. Other operating system versions might instead present the "SHA256" format, which for transfer6.silverpop.com would be: yRXEeqtB90c8QrGzwTzi9lSGSusQaIB+Ur4s+QUgKlc
Here's a list of the fingerprints for each transfer service in SHA256 format:
SHA256
transfer1.silverpop.com iTnDxA3uGt0BTnrwkJH483qkQp3dlFQY52kWojlRIpY
transfer2.silverpop.com 6yOzlZFlkia5VxnV7saotxUgR28O8oh2NGysxsJP2Jc
transfer3.silverpop.com 0zvR7N4XQ4F8JdZIFWLNiasNf8H4u4BEmqrKn/8L72A
transfer4.silverpop.com 3h1Baj99GnRzaPIA/dja8cHYEyaBzTSy/TDOhjj6/sw
transfer5.silverpop.com EVEfkS8+tiLh1yles/B4rggpbY4FQe9vPrIA1kbmTXI
transfer6.silverpop.com yRXEeqtB90c8QrGzwTzi9lSGSusQaIB+Ur4s+QUgKlc
transfer7.silverpop.com kgxy2iO8m3RZB/5LDTrPYsigKHQ5PAvbG6gn/XuQfmc
transfer8.silverpop.com oTxf2GTqa9xDUoYTTVR9gqcUvlHAVo7qD0F9NfPit9s
transfer9.silverpop.com DHYBBzOPJEG19XIgyoz0o5O6uBNjiFCy5rSpLsIzhFU
transfera.silverpop.com AXKk3o8YgUHuGe9cTpD9Df2G6xMRwutI77FsOgaJtT0
When you accept a fingerprint, your sftp client will store the fingerprint and not warn on future connections - unless the fingerprint changes, which isn't something that should happen. You can do the same thing with a GUI program and it will warn with the fingerprint in one or both of the above formats.
For reference, the commands used (assuming a Bash environment):
Function to output the fingerprint for a given hostname (format output will depend on your system):
$ function f { ssh-keyscan $1 > /tmp/tf 2>/dev/null && ssh-keygen -lf /tmp/tf && rm /tmp/tf ; }
List all the fingerprints (SHA256 output example):
$ for e in transfer{{1..9},a}.silverpop.com; do f $e; done
1024 SHA256:iTnDxA3uGt0BTnrwkJH483qkQp3dlFQY52kWojlRIpY transfer1.silverpop.com (RSA)
1024 SHA256:6yOzlZFlkia5VxnV7saotxUgR28O8oh2NGysxsJP2Jc transfer2.silverpop.com (RSA)
2048 SHA256:0zvR7N4XQ4F8JdZIFWLNiasNf8H4u4BEmqrKn/8L72A transfer3.silverpop.com (RSA)
1024 SHA256:3h1Baj99GnRzaPIA/dja8cHYEyaBzTSy/TDOhjj6/sw transfer4.silverpop.com (RSA)
2048 SHA256:EVEfkS8+tiLh1yles/B4rggpbY4FQe9vPrIA1kbmTXI transfer5.silverpop.com (RSA)
2048 SHA256:yRXEeqtB90c8QrGzwTzi9lSGSusQaIB+Ur4s+QUgKlc transfer6.silverpop.com (RSA)
2048 SHA256:kgxy2iO8m3RZB/5LDTrPYsigKHQ5PAvbG6gn/XuQfmc transfer7.silverpop.com (RSA)
2048 SHA256:oTxf2GTqa9xDUoYTTVR9gqcUvlHAVo7qD0F9NfPit9s transfer8.silverpop.com (RSA)
2048 SHA256:DHYBBzOPJEG19XIgyoz0o5O6uBNjiFCy5rSpLsIzhFU transfer9.silverpop.com (RSA)
2048 SHA256:AXKk3o8YgUHuGe9cTpD9Df2G6xMRwutI77FsOgaJtT0 transfera.silverpop.com (RSA)