1
0
mirror of https://github.com/postgres/postgres.git synced 2025-07-02 09:02:37 +03:00

Remove arbitrary restrictions on password length.

This patch started out with the goal of harmonizing various arbitrary
limits on password length, but after awhile a better idea emerged:
let's just get rid of those fixed limits.

recv_password_packet() has an arbitrary limit on the packet size,
which we don't really need, so just drop it.  (Note that this doesn't
really affect anything for MD5 or SCRAM password verification, since
those will hash the user's password to something shorter anyway.
It does matter for auth methods that require a cleartext password.)

Likewise remove the arbitrary error condition in pg_saslprep().

The remaining limits are mostly in client-side code that prompts
for passwords.  To improve those, refactor simple_prompt() so that
it allocates its own result buffer that can be made as big as
necessary.  Actually, it proves best to make a separate routine
pg_get_line() that has essentially the semantics of fgets(), except
that it allocates a suitable result buffer and hence will never
return a truncated line.  (pg_get_line has a lot of potential
applications to replace randomly-sized fgets buffers elsewhere,
but I'll leave that for another patch.)

I built pg_get_line() atop stringinfo.c, which requires moving
that code to src/common/; but that seems fine since it was a poor
fit for src/port/ anyway.

This patch is mostly mine, but it owes a good deal to Nathan Bossart
who pressed for a solution to the password length problem and
created a predecessor patch.  Also thanks to Peter Eisentraut and
Stephen Frost for ideas and discussion.

Discussion: https://postgr.es/m/09512C4F-8CB9-4021-B455-EF4C4F0D55A0@amazon.com
This commit is contained in:
Tom Lane
2020-09-03 20:09:18 -04:00
parent be4b0c0077
commit 67a472d71c
21 changed files with 221 additions and 167 deletions

View File

@ -10,10 +10,17 @@
#ifndef COMMON_STRING_H
#define COMMON_STRING_H
/* functions in src/common/string.c */
extern bool pg_str_endswith(const char *str, const char *end);
extern int strtoint(const char *pg_restrict str, char **pg_restrict endptr,
int base);
extern void pg_clean_ascii(char *str);
extern int pg_strip_crlf(char *str);
/* functions in src/common/pg_get_line.c */
extern char *pg_get_line(FILE *stream);
/* functions in src/common/sprompt.c */
extern char *simple_prompt(const char *prompt, bool echo);
#endif /* COMMON_STRING_H */