There are a few places in git that need to get a username
and password credential from the user; the most notable one
is HTTP authentication for smart-http pushing.
Right now the only choices for providing credentials are to
put them plaintext into your ~/.netrc, or to have git prompt
you (either on the terminal or via an askpass program). The
former is not very secure, and the latter is not very
convenient.
Unfortunately, there is no "always best" solution for
password management. The details will depend on the tradeoff
you want between security and convenience, as well as how
git can integrate with other security systems (e.g., many
operating systems provide a keychain or password wallet for
single sign-on).
This patch abstracts the notion of gathering user
credentials into a few simple functions. These functions can
be backed by our internal git_getpass implementation (which
just prompts the user), or by external helpers which are
free to consult system-specific password wallets, make
custom policy decisions on password caching and storage, or
prompt the user in a non-traditional manner.
The helper protocol aims for simplicity of helper
implementation; see the newly added documentation for
details.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
