Esse é o local padrão. Você pode usar AuthorizedKeysFile
para mudar para um local diferente, mas se você não especificá-lo, ele procurará em ~/.ssh/authorized_keys
A partir da página man (por exemplo, link ):
AuthorizedKeysFile
Specifies the file that contains the public keys that can be used for user authentication. The format is described in the AUTHO- RIZED_KEYS FILE FORMAT section of sshd(8). AuthorizedKeysFile may contain tokens of the form %T which are substituted during connection setup. The following tokens are defined: %% is replaced by a literal '%', %h is replaced by the home directory of the user being authenticated, and %u is replaced by the user- name of that user. After expansion, AuthorizedKeysFile is taken to be an absolute path or one relative to the user's home direc- tory. Multiple files may be listed, separated by whitespace. The default is ''.ssh/authorized_keys .ssh/authorized_keys2''.