This removes a portion of infrastructure introduced by fe0a0b5 to allow
compilation of Postgres in environments where no strong random source is
available, meaning that there is no linking to OpenSSL and no
/dev/urandom (Windows having its own CryptoAPI). No systems shipped
this century lack /dev/urandom, and the buildfarm is actually not
testing this switch at all, so just remove it. This simplifies
particularly some backend code which included a fallback implementation
using shared memory, and removes a set of alternate regression output
files from pgcrypto.
Author: Michael Paquier
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/20181230063219.GG608@paquier.xyz
Per the project style guide, details and hints should have leading
capitalization and end with a period. On the other hand, errcontext should
not be capitalized and should not end with a period. To support well
formatted error contexts in dblink, extend dblink_res_error() to take a
format+arguments rather than a hardcoded string.
Daniel Gustafsson
Discussion: https://postgr.es/m/B3C002C8-21A0-4F53-A06E-8CAB29FCF295@yesql.se
Previously, gen_random_uuid() would fall back to a weak random number
generator, unlike gen_random_bytes() which would just fail. And this was
not made very clear in the docs. For consistency, also make
gen_random_uuid() fail outright, if compiled with --disable-strong-random.
Re-word the error message you get with --disable-strong-random. It is also
used by pgp functions that require random salts, and now also
gen_random_uuid().
Reported by Radek Slupik.
Discussion: https://www.postgresql.org/message-id/20170101232054.10135.50528@wrigleys.postgresql.org
This adds a new routine, pg_strong_random() for generating random bytes,
for use in both frontend and backend. At the moment, it's only used in
the backend, but the upcoming SCRAM authentication patches need strong
random numbers in libpq as well.
pg_strong_random() is based on, and replaces, the existing implementation
in pgcrypto. It can acquire strong random numbers from a number of sources,
depending on what's available:
- OpenSSL RAND_bytes(), if built with OpenSSL
- On Windows, the native cryptographic functions are used
- /dev/urandom
Unlike the current pgcrypto function, the source is chosen by configure.
That makes it easier to test different implementations, and ensures that
we don't accidentally fall back to a less secure implementation, if the
primary source fails. All of those methods are quite reliable, it would be
pretty surprising for them to fail, so we'd rather find out by failing
hard.
If no strong random source is available, we fall back to using erand48(),
seeded from current timestamp, like PostmasterRandom() was. That isn't
cryptographically secure, but allows us to still work on platforms that
don't have any of the above stronger sources. Because it's not very secure,
the built-in implementation is only used if explicitly requested with
--disable-strong-random.
This replaces the more complicated Fortuna algorithm we used to have in
pgcrypto, which is unfortunate, but all modern platforms have /dev/urandom,
so it doesn't seem worth the maintenance effort to keep that. pgcrypto
functions that require strong random numbers will be disabled with
--disable-strong-random.
Original patch by Magnus Hagander, tons of further work by Michael Paquier
and me.
Discussion: https://www.postgresql.org/message-id/CAB7nPqRy3krN8quR9XujMVVHYtXJ0_60nqgVc6oUk8ygyVkZsA@mail.gmail.com
Discussion: https://www.postgresql.org/message-id/CAB7nPqRWkNYRRPJA7-cF+LfroYV10pvjdz6GNvxk-Eee9FypKA@mail.gmail.com
pgp-pubkey-DISABLED test has been unused since 2006, when support for
built-in bignum math was added (commit 1abf76e8). pgp-encrypt-DISABLED has
been unused forever, AFAICS.
Also remove a couple of unused error codes.
This has been the predominant outcome. When the output of decrypting
with a wrong key coincidentally resembled an OpenPGP packet header,
pgcrypto could instead report "Corrupt data", "Not text data" or
"Unsupported compression algorithm". The distinct "Corrupt data"
message added no value. The latter two error messages misled when the
decrypted payload also exhibited fundamental integrity problems. Worse,
error message variance in other systems has enabled cryptologic attacks;
see RFC 4880 section "14. Security Considerations". Whether these
pgcrypto behaviors are likewise exploitable is unknown.
In passing, document that pgcrypto does not resist side-channel attacks.
Back-patch to 9.0 (all supported versions).
Security: CVE-2015-3167
Specifically, on-stack memset() might be removed, so:
* Replace memset() with px_memset()
* Add px_memset to copy_crlf()
* Add px_memset to pgp-s2k.c
Patch by Marko Kreen
Report by PVS-Studio
Backpatch through 8.4.
This warning is new in gcc 4.6 and part of -Wall. This patch cleans
up most of the noise, but there are some still warnings that are
trickier to remove.
padded encryption scheme. Formerly it would try to access res[(unsigned) -1],
which resulted in core dumps on 64-bit machines, and was certainly trouble
waiting to happen on 32-bit machines (though in at least the known case
it was harmless because that byte would be overwritten after return).
Per report from Ken Colson; fix by Marko Kreen.
the pubkey functions a bit. The actual RSA-specific code
there is tiny, most of the patch consists of reorg of the
pubkey code, as lots of it was written as elgamal-only.
---------------------------------------------------------------------------
The SHLIB section was copy-pasted from somewhere and contains
several unnecessary libs. This cleans it up a bit.
-lcrypt
we don't use system crypt()
-lssl, -lssleay32
no SSL here
-lz in win32 section
already added on previous line
-ldes
The chance anybody has it is pretty low.
And the chance pgcrypto works with it is even lower.
Also trim the win32 section.
---------------------------------------------------------------------------
It is already disabled in Makefile, remove code too.
---------------------------------------------------------------------------
I was bit hasty making the random exponent 'k' a prime. Further researh
shows that Elgamal encryption has no specific needs in respect to k,
any random number is fine.
It is bit different for signing, there it needs to be 'relatively prime'
to p - 1, that means GCD(k, p-1) == 1, which is also a lot lighter than
full primality. As we don't do signing, this can be ignored.
This brings major speedup to Elgamal encryption.
---------------------------------------------------------------------------
o pgp_mpi_free: Accept NULLs
o pgp_mpi_cksum: result should be 16bit
o Remove function name from error messages - to be similar to other
SQL functions, and it does not match anyway the called function
o remove couple junk lines
---------------------------------------------------------------------------
o Support for RSA encryption
o Big reorg to better separate generic and algorithm-specific code.
o Regression tests for RSA.
---------------------------------------------------------------------------
o Tom stuck a CVS id into file. I doubt the usefulness of it,
but if it needs to be in the file then rather at the end.
Also tag it as comment for asciidoc.
o Mention bytea vs. text difference
o Couple clarifications
---------------------------------------------------------------------------
There is a choice whether to update it with pgp functions or
remove it. I decided to remove it, updating is pointless.
I've tried to keep the core of pgcrypto relatively independent
from main PostgreSQL, to make it easy to use externally if needed,
and that is good. Eg. that made development of PGP functions much
nicer.
But I have no plans to release it as generic library, so keeping such
doc
up-to-date is waste of time. If anyone is interested in using it in
other products, he can probably bother to read the source too.
Commented source is another thing - I'll try to make another pass
over code to see if there is anything non-obvious that would need
more comments.
---------------------------------------------------------------------------
Marko Kreen
of password-based encryption from RFC2440 (OpenPGP).
The goal of this code is to be more featureful encryption solution
than current encrypt(), which only functionality is running cipher
over data.
Compared to encrypt(), pgp_encrypt() does following:
* It uses the equvialent of random Inital Vector to get cipher
into random state before it processes user data
* Stores SHA-1 of the data into result so any modification
will be detected.
* Remembers if data was text or binary - thus it can decrypt
to/from text data. This was a major nuisance for encrypt().
* Stores info about used algorithms with result, so user needs
not remember them - more user friendly!
* Uses String2Key algorithms (similar to crypt()) with random salt
to generate full-length binary key to be used for encrypting.
* Uses standard format for data - you can feed it to GnuPG, if needed.
Optional features (off by default):
* Can use separate session key - user data will be encrypted
with totally random key, which will be encrypted with S2K
generated key and attached to result.
* Data compression with zlib.
* Can convert between CRLF<->LF line-endings - to get fully
RFC2440-compliant behaviour. This is off by default as
pgcrypto does not know the line-endings of user data.
Interface is simple:
pgp_encrypt(data text, key text) returns bytea
pgp_decrypt(data text, key text) returns text
pgp_encrypt_bytea(data bytea, key text) returns bytea
pgp_decrypt_bytea(data bytea, key text) returns bytea
To change parameters (cipher, compression, mdc):
pgp_encrypt(data text, key text, parms text) returns bytea
pgp_decrypt(data text, key text, parms text) returns text
pgp_encrypt_bytea(data bytea, key text, parms text) returns bytea
pgp_decrypt_bytea(data bytea, key text, parms text) returns bytea
Parameter names I lifted from gpg:
pgp_encrypt('message', 'key', 'compress-algo=1,cipher-algo=aes256')
For text data, pgp_encrypt simply encrypts the PostgreSQL internal data.
This maps to RFC2440 data type 't' - 'extenally specified encoding'.
But this may cause problems if data is dumped and reloaded into database
which as different internal encoding. My next goal is to implement data
type 'u' - which means data is in UTF-8 encoding by converting internal
encoding to UTF-8 and back. And there wont be any compatibility
problems with current code, I think its ok to submit this without UTF-8
encoding by converting internal encoding to UTF-8 and back. And there
wont be any compatibility problems with current code, I think its ok to
submit this without UTF-8 support.
Here is v4 of PGP encrypt. This depends on previously sent
Fortuna-patch, as it uses the px_add_entropy function.
- New function: pgp_key_id() for finding key id's.
- Add SHA1 of user data and key into RNG pools. We need to get
randomness from somewhere, and it is in user best interests
to contribute.
- Regenerate pgp-armor test for SQL_ASCII database.
- Cleanup the key handling so that the pubkey support is less
hackish.
Marko Kreen
Reserve px_get_random_bytes() for strong randomness,
add new function px_get_pseudo_random_bytes() for
weak randomness and use it in gen_salt().
On openssl case, use RAND_pseudo_bytes() for
px_get_pseudo_random_bytes().
Final result is that is user has not configured random
souce but kept the 'silly' one, gen_salt() keeps
working, but pgp_encrypt() will throw error.
Marko Kreen
* Use error codes instead of -1
* px_strerror for new error codes
* calling convention change for px_gen_salt - return error code
* use px_strerror in pgcrypto.c
Marko Kreen
conversion of basic ASCII letters. Remove all uses of strcasecmp and
strncasecmp in favor of new functions pg_strcasecmp and pg_strncasecmp;
remove most but not all direct uses of toupper and tolower in favor of
pg_toupper and pg_tolower. These functions use the same notions of
case folding already developed for identifier case conversion. I left
the straight locale-based folding in place for situations where we are
just manipulating user data and not trying to match it to built-in
strings --- for example, the SQL upper() function is still locale
dependent. Perhaps this will prove not to be what's wanted, but at
the moment we can initdb and pass regression tests in Turkish locale.
o Change all current CVS messages of NOTICE to WARNING. We were going
to do this just before 7.3 beta but it has to be done now, as you will
see below.
o Change current INFO messages that should be controlled by
client_min_messages to NOTICE.
o Force remaining INFO messages, like from EXPLAIN, VACUUM VERBOSE, etc.
to always go to the client.
o Remove INFO from the client_min_messages options and add NOTICE.
Seems we do need three non-ERROR elog levels to handle the various
behaviors we need for these messages.
Regression passed.
failures on FreeBSD. This patch replaces uint -> unsigned.
This was reported by Daniel Holtzman against 0.4pre3 standalone
package, but it needs fixing in contrib/pgcrypto too.
Marko Kreen
Michael Paquier