struct libssh2_knownhost *known,
char *buffer, size_t buflen,
Converts a single known host to a single line of output for storage, using
the type output format.
known identifies which particular known host
buffer points to an allocated buffer
buflen is the size of the buffer. See RETURN VALUE about the size.
outlen must be a pointer to a size_t variable that will get the output
length of the stored data chunk. The number does not included the trailing
type specifies what file type it is, and
LIBSSH2_KNOWNHOST_FILE_OPENSSH is the only currently supported