Fix recently-introduced breakage in psql's \connect command.

Through my misreading of what the existing code actually did,
commits 85c54287a et al. broke psql's behavior for the case where
"\c connstring" provides a password in the connstring.  We should
use that password in such a case, but as of 85c54287a we ignored it
(and instead, prompted for a password).

Commit 94929f1cf fixed that in HEAD, but since I thought it was
cleaning up a longstanding misbehavior and not one I'd just created,
I didn't back-patch it.

Hence, back-patch the portions of 94929f1cf having to do with
password management.  In addition to fixing the introduced bug,
this means that "\c -reuse-previous=on connstring" will allow
re-use of an existing connection's password if the connstring
doesn't change user/host/port.  That didn't happen before, but
it seems like a bug fix, and anyway I'm loath to have significant
differences in this code across versions.

Also fix an error with the same root cause about whether or not to
override a connstring's setting of client_encoding.  As of 85c54287a
we always did so; restore the previous behavior of overriding only
when stdin/stdout are a terminal and there's no environment setting
of PGCLIENTENCODING.  (I find that definition a bit surprising, but
right now doesn't seem like the time to revisit it.)

Per bug #16746 from Krzysztof Gradek.  As with the previous patch,
back-patch to all supported branches.

Discussion: https://postgr.es/m/16746-44b30e2edf4335d4@postgresql.org
This commit is contained in:
Tom Lane 2020-11-29 15:22:04 -05:00
parent 414fb255e5
commit e2d5de1500
2 changed files with 51 additions and 17 deletions

View File

@ -844,6 +844,8 @@ testdb=>
is changed from its previous value using the positional syntax,
any <replaceable>hostaddr</replaceable> setting present in the
existing connection's parameters is dropped.
Also, any password used for the existing connection will be re-used
only if the user, host, and port settings are not changed.
When the command neither specifies nor reuses a particular parameter,
the <application>libpq</application> default is used.
</para>

View File

@ -1636,6 +1636,7 @@ do_connect(enum trivalue reuse_previous_specification,
int nconnopts = 0;
bool same_host = false;
char *password = NULL;
char *client_encoding;
bool success = true;
bool keep_password = true;
bool has_connection_string;
@ -1706,6 +1707,7 @@ do_connect(enum trivalue reuse_previous_specification,
{
PQconninfoOption *ci;
PQconninfoOption *replci;
bool have_password = false;
for (ci = cinfo, replci = replcinfo;
ci->keyword && replci->keyword;
@ -1724,6 +1726,26 @@ do_connect(enum trivalue reuse_previous_specification,
replci->val = ci->val;
ci->val = swap;
/*
* Check whether connstring provides options affecting
* password re-use. While any change in user, host,
* hostaddr, or port causes us to ignore the old
* connection's password, we don't force that for
* dbname, since passwords aren't database-specific.
*/
if (replci->val == NULL ||
strcmp(ci->val, replci->val) != 0)
{
if (strcmp(replci->keyword, "user") == 0 ||
strcmp(replci->keyword, "host") == 0 ||
strcmp(replci->keyword, "hostaddr") == 0 ||
strcmp(replci->keyword, "port") == 0)
keep_password = false;
}
/* Also note whether connstring contains a password. */
if (strcmp(replci->keyword, "password") == 0)
have_password = true;
}
}
Assert(ci->keyword == NULL && replci->keyword == NULL);
@ -1733,8 +1755,13 @@ do_connect(enum trivalue reuse_previous_specification,
PQconninfoFree(replcinfo);
/* We never re-use a password with a conninfo string. */
keep_password = false;
/*
* If the connstring contains a password, tell the loop below
* that we may use it, regardless of other settings (i.e.,
* cinfo's password is no longer an "old" password).
*/
if (have_password)
keep_password = true;
/* Don't let code below try to inject dbname into params. */
dbname = NULL;
@ -1815,14 +1842,16 @@ do_connect(enum trivalue reuse_previous_specification,
{
password = prompt_for_password(user);
}
else if (o_conn && keep_password)
{
password = PQpass(o_conn);
if (password && *password)
password = pg_strdup(password);
else
password = NULL;
}
/*
* Consider whether to force client_encoding to "auto" (overriding
* anything in the connection string). We do so if we have a terminal
* connection and there is no PGCLIENTENCODING environment setting.
*/
if (pset.notty || getenv("PGCLIENTENCODING"))
client_encoding = NULL;
else
client_encoding = "auto";
/* Loop till we have a connection or fail, which we might've already */
while (success)
@ -1834,12 +1863,12 @@ do_connect(enum trivalue reuse_previous_specification,
/*
* Copy non-default settings into the PQconnectdbParams parameter
* arrays; but override any values specified old-style, as well as the
* password and a couple of fields we want to set forcibly.
* arrays; but inject any values specified old-style, as well as any
* interactively-obtained password, and a couple of fields we want to
* set forcibly.
*
* If you change this code, see also the initial-connection code in
* main(). For no good reason, a connection string password= takes
* precedence in main() but not here.
* main().
*/
for (ci = cinfo; ci->keyword; ci++)
{
@ -1858,12 +1887,15 @@ do_connect(enum trivalue reuse_previous_specification,
}
else if (port && strcmp(ci->keyword, "port") == 0)
values[paramnum++] = port;
else if (strcmp(ci->keyword, "password") == 0)
/* If !keep_password, we unconditionally drop old password */
else if ((password || !keep_password) &&
strcmp(ci->keyword, "password") == 0)
values[paramnum++] = password;
else if (strcmp(ci->keyword, "fallback_application_name") == 0)
values[paramnum++] = pset.progname;
else if (strcmp(ci->keyword, "client_encoding") == 0)
values[paramnum++] = (pset.notty || getenv("PGCLIENTENCODING")) ? NULL : "auto";
else if (client_encoding &&
strcmp(ci->keyword, "client_encoding") == 0)
values[paramnum++] = client_encoding;
else if (ci->val)
values[paramnum++] = ci->val;
/* else, don't bother making libpq parse this keyword */