Aside from FTP, TFTP and SCP file transfers, there's an alternative way of transferring ASA files (OS, ASDM, AnyConnect images, etc.) to the Cisco ASA flash memory (disk0:) via ASDM. The file transfer is slow compared to an FTP but it gets the job done. You can transfer files from your local PC to the ASA flash via ASDM by going to Tools
> File Management.
Select File Transfer > Between Local PC and Flash.
Select a file > select disk0: (ASA flash) > click the right arrow.
As best practice, validate the ASA image file using either the MD5 or SHA-512 hash file validation command to ensure the file wasn't compromised. You can compare the output from Cisco's download page.
ciscoasa# verify /md5 disk0:/asa9xyz-smp-k8.bin
<OUTPUT TRUNCATED>
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Done!
verify /MD5 (disk0:/asa9xyz-smp-k8.bin) = b6d183a5e0b273b5fd40fd8a3ac76bed
Select File Transfer > Between Local PC and Flash.
Select a file > select disk0: (ASA flash) > click the right arrow.
As best practice, validate the ASA image file using either the MD5 or SHA-512 hash file validation command to ensure the file wasn't compromised. You can compare the output from Cisco's download page.
ciscoasa# verify /md5 disk0:/asa9xyz-smp-k8.bin
<OUTPUT TRUNCATED>
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Done!
verify /MD5 (disk0:/asa9xyz-smp-k8.bin) = b6d183a5e0b273b5fd40fd8a3ac76bed