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path: root/src/common/md5_common.c
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2025-05-08Use 'void *' for arbitrary buffers, 'uint8 *' for byte arraysHeikki Linnakangas
A 'void *' argument suggests that the caller might pass an arbitrary struct, which is appropriate for functions like libc's read/write, or pq_sendbytes(). 'uint8 *' is more appropriate for byte arrays that have no structure, like the cancellation keys or SCRAM tokens. Some places used 'char *', but 'uint8 *' is better because 'char *' is commonly used for null-terminated strings. Change code around SCRAM, MD5 authentication, and cancellation key handling to follow these conventions. Discussion: https://www.postgresql.org/message-id/61be9e31-7b7d-49d5-bc11-721800d89d64@eisentraut.org
2025-01-01Update copyright for 2025Bruce Momjian
Backpatch-through: 13
2024-03-14Fix documentation comment for pg_md5_hashDaniel Gustafsson
Commit b69aba74578 added the errstr parameter to pg_md5_hash but missed updating the synopsis in the documentation comment. The follow-up commit 587de223f03 added the parameter to the list of outputs. The returnvalue had been changed from integer to bool before that but remained in the synopsis. This fixes both. Author: Tatsuro Yamada <tatsuro.yamada@ntt.com> Discussion: https://postgr.es/m/TYYPR01MB82313576150CC86084A122CD9E292@TYYPR01MB8231.jpnprd01.prod.outlook.com
2024-01-04Update copyright for 2024Bruce Momjian
Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
2023-01-02Update copyright for 2023Bruce Momjian
Backpatch-through: 11
2022-04-19Add missing error handling in pg_md5_hash().Tom Lane
It failed to provide an error string as expected for the admittedly-unlikely case of OOM in pg_cryptohash_create(). Also, make it initialize *errstr to NULL for success, as pg_md5_binary() does. Also add missing comments. Readers should not have to reverse-engineer the API spec for a publicly visible routine.
2022-01-11Improve error handling of cryptohash computationsMichael Paquier
The existing cryptohash facility was causing problems in some code paths related to MD5 (frontend and backend) that relied on the fact that the only type of error that could happen would be an OOM, as the MD5 implementation used in PostgreSQL ~13 (the in-core implementation is used when compiling with or without OpenSSL in those older versions), could fail only under this circumstance. The new cryptohash facilities can fail for reasons other than OOMs, like attempting MD5 when FIPS is enabled (upstream OpenSSL allows that up to 1.0.2, Fedora and Photon patch OpenSSL 1.1.1 to allow that), so this would cause incorrect reports to show up. This commit extends the cryptohash APIs so as callers of those routines can fetch more context when an error happens, by using a new routine called pg_cryptohash_error(). The error states are stored within each implementation's internal context data, so as it is possible to extend the logic depending on what's suited for an implementation. The default implementation requires few error states, but OpenSSL could report various issues depending on its internal state so more is needed in cryptohash_openssl.c, and the code is shaped so as we are always able to grab the necessary information. The core code is changed to adapt to the new error routine, painting more "const" across the call stack where the static errors are stored, particularly in authentication code paths on variables that provide log details. This way, any future changes would warn if attempting to free these strings. The MD5 authentication code was also a bit blurry about the handling of "logdetail" (LOG sent to the postmaster), so improve the comments related that, while on it. The origin of the problem is 87ae969, that introduced the centralized cryptohash facility. Extra changes are done for pgcrypto in v14 for the non-OpenSSL code path to cope with the improvements done by this commit. Reported-by: Michael Mühlbeyer Author: Michael Paquier Reviewed-by: Tom Lane Discussion: https://postgr.es/m/89B7F072-5BBE-4C92-903E-D83E865D9367@trivadis.com Backpatch-through: 14
2022-01-08Update copyright for 2022Bruce Momjian
Backpatch-through: 10
2021-02-15Add result size as argument of pg_cryptohash_final() for overflow checksMichael Paquier
With its current design, a careless use of pg_cryptohash_final() could would result in an out-of-bound write in memory as the size of the destination buffer to store the result digest is not known to the cryptohash internals, without the caller knowing about that. This commit adds a new argument to pg_cryptohash_final() to allow such sanity checks, and implements such defenses. The internals of SCRAM for HMAC could be tightened a bit more, but as everything is based on SCRAM_KEY_LEN with uses particular to this code there is no need to complicate its interface more than necessary, and this comes back to the refactoring of HMAC in core. Except that, this minimizes the uses of the existing DIGEST_LENGTH variables, relying instead on sizeof() for the result sizes. In ossp-uuid, this also makes the code more defensive, as it already relied on dce_uuid_t being at least the size of a MD5 digest. This is in philosophy similar to cfc40d3 for base64.c and aef8948 for hex.c. Reported-by: Ranier Vilela Author: Michael Paquier, Ranier Vilela Reviewed-by: Kyotaro Horiguchi Discussion: https://postgr.es/m/CAEudQAoqEGmcff3J4sTSV-R_16Monuz-UpJFbf_dnVH=APr02Q@mail.gmail.com
2021-01-02Update copyright for 2021Bruce Momjian
Backpatch-through: 9.5
2020-12-14Improve some code around cryptohash functionsMichael Paquier
This adjusts some code related to recent changes for cryptohash functions: - Add a variable in md5.h to track down the size of a computed result, moved from pgcrypto. Note that pg_md5_hash() assumed a result of this size already. - Call explicit_bzero() on the hashed data when freeing the context for fallback implementations. For MD5, particularly, it would be annoying to leave some non-zeroed data around. - Clean up some code related to recent changes of uuid-ossp. .gitignore still included md5.c and a comment was incorrect. Discussion: https://postgr.es/m/X9HXKTgrvJvYO7Oh@paquier.xyz
2020-12-10Refactor MD5 implementations according to new cryptohash infrastructureMichael Paquier
This commit heavily reorganizes the MD5 implementations that exist in the tree in various aspects. First, MD5 is added to the list of options available in cryptohash.c and cryptohash_openssl.c. This means that if building with OpenSSL, EVP is used for MD5 instead of the fallback implementation that Postgres had for ages. With the recent refactoring work for cryptohash functions, this change is straight-forward. If not building with OpenSSL, a fallback implementation internal to src/common/ is used. Second, this reduces the number of MD5 implementations present in the tree from two to one, by moving the KAME implementation from pgcrypto to src/common/, and by removing the implementation that existed in src/common/. KAME was already structured with an init/update/final set of routines by pgcrypto (see original pgcrypto/md5.h) for compatibility with OpenSSL, so moving it to src/common/ has proved to be a straight-forward move, requiring no actual manipulation of the internals of each routine. Some benchmarking has not shown any performance gap between both implementations. Similarly to the fallback implementation used for SHA2, the fallback implementation of MD5 is moved to src/common/md5.c with an internal header called md5_int.h for the init, update and final routines. This gets then consumed by cryptohash.c. The original routines used for MD5-hashed passwords are moved to a separate file called md5_common.c, also in src/common/, aimed at being shared between all MD5 implementations as utility routines to keep compatibility with any code relying on them. Like the SHA2 changes, this commit had its round of tests on both Linux and Windows, across all versions of OpenSSL supported on HEAD, with and even without OpenSSL. Author: Michael Paquier Reviewed-by: Daniel Gustafsson Discussion: https://postgr.es/m/20201106073434.GA4961@paquier.xyz