To set a password directly to an hash i used gsed so far for a long long time. But you never stop to learn. There is a much simpler way. My colleague Detlef Drewanz pointed me to it today :
passwd -p <hash> <username>
For example to change my password to changeme123 you use it like this:
-p hash Specifies the exact string value to be placed in the shadow pass- word field. The user must have both the solaris.passwd.assign and solaris.passwd.nocheck authorizations. It is intended to be used for scripting password hash updates. Its use is generally discour- aged, as the hashed password is visible through ps(1) while the command runs.This works in Solaris since Solaris 11.3 SRU 4.