Hi Daniel,
I hope to be correct: I suspect clients' Public SSH Keys - your RFP is asking about those ones (SSH Key length apart), isn't it? - longer than 1024 ASCII characters can't be stored on the Switch by means of an upload of a text file containing them and - again...I hope to have read the documentation correctly - it also looks like the Switch is able to read (and store) up to 10 public SSH Keys only.
Reference: the Aruba 5400R/3810M Management and Configuration Guide for ArubaOS-Switch 16.07 at page 589 (Paragraph "An attempt to copy a client public-key file into the switch has failed and the switch lists one of the following messages").