Posted by jpluimers on 2020/09/01
The traditional iron triangle of planning is turned up-side down when being agile: [WayBack] The iron triangle of planning | Atlassian.
On the left, the traditional triangle, on the right the agile one.
Via: [WayBack] The iron triangle of planning The Agile Coach – Marjan Venema – Google+
–jeroen
Posted in Agile, Development, Software Development | Leave a Comment »
Posted by jpluimers on 2020/08/31
From an interesting thread at [WayBack] What’s the piece of Delphi knowledge you find yourself looking up over and over again? For me format strings is probably the thing that most stubbornly… – Lachlan Gemmell – Google+
On the generics side, I have wrote a few bits in my blog before, often pointing to information by others (many by Stefan Glienke as his skills on this topic are beyond excellent):
And on records:
There are some very good books on Delphi though that dig deeper than the documentation:
–jeroen
Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | 4 Comments »
Posted by jpluimers on 2020/08/27
[WayBack] Debugging is like being the detective in a crime movie where you are also the murderer. ROFL. You can grab it from Amazon https://goo.gl/SDP8fU – Markus Korsmeier – Google+
Edit: 20240818 – this shows the drawbacks of using redirecters: the Cyberciti one to which Googl redirects was already dead before Googl got shut down completely:
web.archive.org/web/20221206133240/https://goo.gl/SDP8fU -> https://web.archive.org/web/20221206133240/https://www.cyberciti.biz/go/a/Tshirt-Debugging-is-like-being-the-detective.php -> www.cyberciti.biz/go/a/Tshirt-Debugging-is-like-being-the-detective.php -> www.cyberciti.biz
--jeroen
Posted in Debugging, Development, Fun, Quotes, Software Development, T-Shirt quotes | Leave a Comment »
Posted by jpluimers on 2020/08/26
Some interesting bits from [WayBack] Password hashing on client side is insecure · Issue #44 · meteor/meteor-feature-requests · GitHub by tysonclugg:
Stop with the client side hashing – it’s security theatrics. Submit plain text passwords over TLS. The focus should be on having TLS enabled by default, and making sure the server has a sufficient amount of cryptographic work-factor during authentication to render brute-force attacks ineffective (eg: use server-side bcrypt).
Honestly, javascript password shenanigans in the browser is as dumb as backing up HOTP/TOTP secrets from your 2FA app in case you lose your phone. Hint: that changes “something you have” into “something you know”, authenticating with two things you know is single factor authentication. And yet, a group of “smart people” created an app that allows just that. Don’t be another one of those “smart people”.
If you’re still unsure about ditching client-side password hashing, have a read on what others have said:
- https://www.nccgroup.trust/us/about-us/newsroom-and-events/blog/2011/august/javascript-cryptography-considered-harmful/
- http://thisinterestsme.com/client-side-hashing-secure/
- https://security.stackexchange.com/questions/53594/why-is-client-side-hashing-of-a-password-so-uncommon
- https://cybergibbons.com/security-2/stop-doing-client-side-password-hashing/
- https://www.reddit.com/r/crypto/comments/375lor/is_client_side_hashing_of_passwords_viable_to/
5.1. One of the comments specifically mentions SRP, but goes on to say:You’ll probably be interested in the Secure Remote Password protocol (SRP). It uses a variant of the Diffie-Hellman key negotiation protocol to simultaneously authenticate the client with the server, the server with the client, and establish a session key for sending secrets between the client and server. It’s not very useful with web applications, because you still have to trust the encrypted channel to deliver the right version of the JavaScript to manage the communication. It could be useful for other client/server applications, where the client application can be verified and isn’t retransmitted every session.
If you’re still not convinced after reading all of the above, I’d suggest you contact a notable cryptographer for further advice. Prof. David A. Wagner might be a good choice.
…
Meanwhile, client side password hashing hinders upgrades to the password hashing scheme, and nothing has been done.
…
Hindering, not preventing. Of course you can send many hashed variants of the password from the client to the server to account for whichever legacy hash exists in the DB, but in my that weakens the system by allowing many hashes to be submitted simultaneously (or in short order) with no work factor. The result is that brute forcing an account becomes much easier.
and in [WayBack] Password hashing on client side is insecure · Issue #4363 · meteor/meteor · GitHub:
On compatibility (the reason I visited the Meteor password hashing code in the first place), upgrading to new hashing algorithms (which MUST be done from time to time) is much easier if the plaintext password is passed to the server, and transparent to the client as no new API is required to handle the case of upgrading from an old hash to a new hash. The generally accepted means of storing hashes is “$” such as “
pbkdf2_sha256$15000$ZLpQISRxzhY0$fxrQcKxhkG//nHg10NrkulhvWkAqWbWeQg4QeD7c59E=”
This is a PBKDF2 hash for the password “pass” which includes the number of rounds, the salt and the resultant hash ready to be verified and upgraded if required, for example by increasing the number of rounds from 150000 to 250000, or ready to be swapped to a different algorithm altogether (eg: pbkdf2_sha512).
NIST in 2017 on key derivation functions:
In June 2017, NIST issued a new revision of their digital authentication guidelines, NIST SP 800-63B-3,[12]:5.1.1.1 stating that: “Verifiers SHALL store memorized secrets [i.e. passwords] in a form that is resistant to offline attacks. Memorized secrets SHALL be salted and hashed using a suitable one-way key derivation function. Key derivation functions take a password, a salt, and a cost factor as inputs then generate a password hash. Their purpose is to make each password guessing trial by an attacker who has obtained a password hash file expensive and therefore the cost of a guessing attack high or prohibitive.” and that “The salt SHALL be at least 32 bits in length and be chosen arbitrarily so as to minimize salt value collisions among stored hashes.”
It looks like Argon2 is better than bcrypt and PBKDF2_SHA512. The 2017 hashing speed table:
sha1: 68.000.000.000 hash/s sha256: 23.000.000.000 hash/s sha512: 8.600.000.000 hash/s sha3: 6.500.000.000 hash/s bcrypt(5): 105.700 hash/s(for work factor 15 it’s hash/sec)
sha256crypt: 3.100.000 hash/s And with stretching: pbkdf2-sha1(1000 r): 26.000.000 hash/s pbkdf2-sha256: 9.400.000 hash/s pbkdf2-sha512: 3.400.000 hash/s Also, one commenter mentioned that using future telling skills we expect that hash values improve 55% annually, which is exciting and scary at once. —grin✎ 13:51, 10 October 2017 (UTC)
The cost is confirmed at [WayBack] bcrypt cost 10/12/14 brute force time? – Information Security Stack Exchange, so in 2020 it should be somewhere around the 12-14 range.
Moore’s law does not fully apply any more for single core performance, but there are other potential optimisations, and it is unclear how future hash attacks will improve, so it is better to use a mini-bench mark to calculate a good cost, see:
Delphi implementations:
Via:
Further reading:
–jeroen
Posted in Development, Hashing, Power User, Security, Software Development | Leave a Comment »
Posted by jpluimers on 2020/08/25
If you ever get a “Fatal: F1027 Unit not found: ‘System.pas’ or binary equivalents (.dcu)” – Google Search, then it is likely because you:
This is common for unattended builds (like build-automation).
For each run, the Delphi IDE will save an EnvOptions.dproj with global settings.
Since build scripts should not rely on global settings, you need to ensure those are in your project settings.
Some background reading on this:
–jeroen
Posted in Delphi, Development, Software Development | Leave a Comment »
Posted by jpluimers on 2020/08/25
In addition to Shared/IShared, there is also Weak/IWeakReference in Spring.pas; these blog post explain more about them:
{$REGION 'Shared smart pointer'} at the current repository):
{$REGION 'Weak smart pointer'} at the current repository):
Related: If you were using Managed / IManaged in Spring4D, be aware they got renamed to Shared / IShared.
–jeroen
Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »
Posted by jpluimers on 2020/08/25
Interesting thoughts: [WayBack] 10 Tips on How to be a Great Programmer – Java, SQL and jOOQ.
Via: [WayBack] The bitterness of poor quality remains long after the sweetness of low price is forgotten — Benjamin Franklin (not sure this is true, could not find a source) – Thomas Mueller (dummzeuch) – Google+
–jeroen
Posted in Conference Topics, Conferences, Development, Event, Software Development | Leave a Comment »
Posted by jpluimers on 2020/08/21
find . -type f -name '\.*' -printMust work if you want list every hidden file down in the directory hierarchy.
This sort of works on Linux, but fails on VMware ESXi (on Linux it only works when applying -maxdepth 1, deeper levels fails because they list all files where the top directory starts with a .):
If you want hidden files and hidden directories, without . and .. :find -regex '\./\..+' -print
This works on both Linux and VMware ESXi:
If you want hidden files and hidden directories, without . and .. :
find . \( -type f -o -type d \) -name '\.*' -print
Based on:
–jeroen
Posted in *nix, *nix-tools, bash, bash, Development, Power User, Scripting, Software Development | Leave a Comment »
Posted by jpluimers on 2020/08/20
A while ago, I had to figure out how to get some GExperts stuff cross-compile to older Delphi versions, because of UITypes usage that is not available in Delphi XE and lower (but much of what it contains is in the Types unit).
So I went down memory lane, as I remember in Delphi 2, the Delphi 1 WinTypes and WinProcs units were merged into the Windows unit.
A quick search revealed the stackoverflow entry mentioned here:
for the Delphi 1 -> Delphi 2 migrations, these aliases were used where multiple units pointed to the same one:
WinTypes=Windows;WinProcs=Windows;DbiProcs=BDE;DbiTypes=BDE;DbiErrs=BDESee [WayBack] delphi – wintypes.dcu not found and code completion stops working – Stack Overflow
A longer search found this in my own archives:
File D2-CS-2.0\DEMOS\DOC\AUTOPROJ\AUTOPROJ.DOF
Has this line:
UnitAliases=WinTypes=Windows;WinProcs=Windows
Source: [WayBack] GX_GenericUtils.pas fails to build in Delphi 2007 because it uses unit UITypes · Issue #22 · jpluimers/GExperts · GitHub
You can use unit aliases so your applications cannot use the VCL any more.
The trick is to alias Forms or VCL.Forms into something that does not exists, like Forms=__no_VCL_Forms__. The reason this works is that any VCL application uses the Forms unit because of the Forms.Application variable.
Reference:
–jeroen
Posted in Conference Topics, Conferences, Delphi, Development, Event, GExperts, Software Development | Leave a Comment »
Posted by jpluimers on 2020/08/20
A few posts on why not to use the TPL and be very careful with regular RTL threading code:
In my opinion, threading code needs to be written and maintained by people that live and breath multi-threading. Over the years, RTL and TPL have not lived up to that, but a library like [WayBack] OmniThreadLibrary has.
If you still insist on the TPL, or want to break it, start with these posts: [WayBack] Parallel Programming Archives • Stephen Ball’s Technical Blog
–jeroen
Posted in Delphi, Development, Software Development | 1 Comment »
The Wiert Corner - irregular stream of stuff 