[Verizon] Can someone explain what the md5 sum does? and why its sometimes offered to download?

[litobirdy]

I've had the nexus since launch and i've seen md5 sum with a string of characters after and sometimes its offered to download with the rom but what for? I have yet to see what this is for.

 

[jbdan]

Check out this thread

 

[breadnatty08]

md5sum - Wikipedia, the free encyclopedia
I had to look it up myself since I didn't know either. I'm sure someone else will chime in with a dummy guide to it.

Edit: And I knew Jbdan would ninja me. Guy is too damn fast!

 

[litobirdy]

Hmm so its just a verification to make sure you have the right checksum on the file you downloaded. Ok doesnt sound like somethign i'll never need to download if I download roms n stuff from trusted sources.

 

[trophynuts]

Hmm so its just a verification to make sure you have the right checksum on the file you downloaded. Ok doesnt sound like somethign i'll never need to download if I download roms n stuff from trusted sources.

wrong....its more used to make sure you get a valid download or one that is not corrupted. Just because you downloaded from a trusted source doesn't mean that something can't happen in the download to corrupt it. I have seen a lot of bad downloads lead to people resetting their device because they didn't check the MD5 to verify it's integrity. Always check your MD5.

 

[litobirdy]

wrong....its more used to make sure you get a valid download or one that is not corrupted. Just because you downloaded from a trusted source doesn't mean that something can't happen in the download to corrupt it. I have seen a lot of bad downloads lead to people resetting their device because they didn't check the MD5 to verify it's integrity. Always check your MD5.

oh, ok thanks

 

[trophynuts]

for files that you download on your phone you can use this awesome app that some dude made

 

[SecondShot]

As stated, they are "fingerprints" for files. If the md5 sums don't match, your files are not identical. Also, when making a nandroid in CWMR, the restore process checks your md5 sum and if it doesn't match that of the original backup, it won't load it. If you ever made a name change to a backup file through windows file explorer while your phone was connected, you know that the md5 sometimes won't match and you can't restore until you change the name back. If you change the name through ROM Manager, it will work. In fact, that is the only reason I use Rom Manager (ie I don't load ROMS or do backups with it.)

Note: ES File Explorer and Astro File Explorer both have features that allow you to verify md5 sums. If Root Explorer does, I haven't figured out how to do that.

 

[scary alien]

for files that you download on your phone you can use this awesome app that some dude made

And I just updated this past weekend!

Note: not many folks know that it will also (in addition to calculating various checksums):

1. verify the contents of a signed jar-type file (.apk, signed ROM or update.zip, etc.) without needing to know any of the checksums (they are already built-in to signed files)

2. perform a verification of your Nandroid backup (custom recoveries do this anyway before a restore is allowed, but you can do it manually outside of ClockworkMod).

Cheers!

 

[trophynuts]

@Scary yeah i noticed i got an update notification for it the other day. I thought to myself Man Scary must have gotten some free time to work on his apps lol.

 

[scary alien]

@Scary yeah i noticed i got an update notification for it the other day. I thought to myself Man Scary must have gotten some free time to work on his apps lol.

LOL, well "free" is a relative term....

I spent about 10 hours debugging the issues I had with the stupid orientation coding which turned-out that all I needed was four simple lines of code .

I learned a lot, though (a lot that I didn't originally intend to ).

I've got some other ideas for minor tweaks and updates (stuff I've been intending to do for a while, just been crazy busy with AF stuff and work and real life, etc.).

Thanks for everyone's support and feedback...let me know if you have any ideas, questions, or comments (scary.alien@gmail.com ).

Cheers!

 

[breadnatty08]

I understand that renaming a nandroid in Windows can cause issues, but how often are these ROMs corrupted? I never had an issue with my Droid grabbing ROMs from various sources (Mega, AF, AndroidCentral etc). Just curious if this is something to keep an eye on.

 

[scary alien]

I understand that renaming a nandroid in Windows can cause issues, but how often are these ROMs corrupted? I never had an issue with my Droid grabbing ROMs from various sources (Mega, AF, AndroidCentral etc). Just curious if this is something to keep an eye on.

Its not necessarily the source of data you are downloading (but it could be), but rather, the downloading platform (i.e., your PC, your phone, etc.) and means/transport.

My rationale for saying this is that I think the source file is (hopefully) never going to change p), but certainly the download target, method, and connection quality (i.e., internet, speed, etc.).

I've had bad downloads using my PC (different browsers) and phone (different browsers (Opera has played more nicely in the past than the stock browser, etc.).

Shortly after launch day, I downloaded the 4.0.1 stock / factory images from Google. I was about to flash them for testing and documenting the procedure and figured I'd better do my due-diligence and check the MD5s--sure enough, I had a partial download (i.e., from Google to my PC--no phone involved).

I think that when I unzipped the factory image, winrar might have noticed it was a corrupted .zip file, but I'm not 100% about that...

So, I always try to verify the checksum or validity of a file that I download (if possible).

Trust, but verfiy .

Cheers!