I like that idea. I did replace the screen on a phone once. Maybe there is something on youtube that will show me how to remove those parts.

Thanks.

It is a PIII 850 with 384M Ram.

What I found is that any OS that will run on it, will not have a version of python which works with the current release of Electrum.

I might go with using a non-activated android phone. I don't really like this though because it seem like they are always trying to connect to some kind of network.

I think people are steering me in the wrong direction. My question was about how to get an Electrum offline wallet running again on a very old desktop. Most of the advice is ignoring my hardware and assuming this is a newer PC. I think I am forced to upgrade now.

Thanks.

Which download are you speaking about? The Linux version located at: https://download.electrum.org/4.0.9/electrum-4.0.9-x86_64.AppImage is a 64 bit executable.

OK. Tried it. Kernal panic.

It does not matter, but I am pretty sure I will have problems with a 64 bit on a 32 bit os anyway.

I saw it, but I did not try that OS. I will give it a try.

But, How were you able to get the 64 bit electrum to run on a 32 bit OS?

Hey guys,

I just noticed that the documentation suggests that I could use an android phone to sign the transactions. I am sure I have an old phone around here that I could factory reset and leave in airplane mode. That might be a good solution. Does anyone know if the Android version will work in this fashion? (Completely off line.)

Thanks,
James.

I tried Ubuntu 16.4, Lubuntu 18.4 & 16.4, a few versions of puppy.

I don't feel it matters though. I think the idea was doomed to fail from the start. I see that the Linux build of Electrum is for 64bit. My hardware is 32bit.

I am thinking about creating a Linux VM to run inside of Windows 10. Then keep my signing wallet inside that VM and only mount that VM when the laptop is not connect to WIFI. It is not exactly a cold wallet, but I think it gives me a little more security.

Thank you Bob, maybe you missed the first part of the thread. I have a 20yo Pentium with XP that I was using as an offline cold wallet to sign transactions created with my online laptop. It is the only thing I was using that PC for. The most recent version of Electrum does not work on XP. There are legacy versions of Electrum which work on XP, but all of them are too old to connect to any server nodes.

The suggestion was to install Linux on the box. The bios only supports boot up from DVD, floppys or HD. I needed a DVD burner to create an installation disk. I wanted a DVD burner anyway. I have a bunch tvs and dvd players. I also have a couple hundred movie iso files. I wanted to be able to burn movies again too.

So my burner arrived and I gave it a shot, but no success. I tried about 5 varieties of Linux which claimed to be able to run on my hardware. All seem to start ok and show some kind of splash screen, but eventually all would hang and display a plain black screen.

I guess I will need to spend money on something else.

Thanks for all the help.

Ah.. I got it now. I agree. The transaction always comes first and then that tells you the quantity of input and output maps that follow.

I might have considered making the key values unique across all scopes to eliminate the possibility of confusion.

I think all my questions are answered. Thank you. It is a very good discussion.

I am on the lookout for a web based utility that will accept an uploaded psbt file and return a json representation of the transaction. Please let me know if you are aware of one.

I am still waiting for my DVD burner to arrive. Once that gets here I will try to update my legacy hardware with ubuntu and let you know if I get my offline wallet working again.

Kind Regards,
James.

Thank you HCP,

I apologize for letting this go way beyond the scope of my original question. But, I am intrigued by this and I want to learn more.

I completely understand your response. 2 inputs = 2 maps, 2 outputs = 2 maps. But, you created the transaction and know what to expect. How does a person, or algorithm decode this if they have no prior knowledge of the transaction.

My confusion is with the data types that duplicate the values from the other scope.

Scope Type Values    Name    BIP Number
Input     0    PSBT_IN_NON_WITNESS_UTXO    BIP 174
Input     1    PSBT_IN_WITNESS_UTXO    BIP 174
Input     2    PSBT_IN_PARTIAL_SIG    BIP 174
Output    0    PSBT_OUT_REDEEM_SCRIPT    BIP 174
Output    1    PSBT_OUT_WITNESS_SCRIPT    BIP 174
Output    2    PSBT_OUT_BIP32_DERIVATION    BIP 174


Do I need to also look at the format of the data to determine which scope it belongs to? Or, am I guaranteed that each map will contain at least one data type value which is unique across both Input and Output and I can use that to determine which scope the map belongs to?

Thank you HCP,

I think I understand 95% of this now. I did review the specification again and I do see my mistake. It is one Global Map followed by 1 or more Input maps followed by 1 or more Output maps.

I can see how to parse out all of the key-value maps. I am still confused how to determine where Input maps end and the Output maps start. The keys are only unique in the same "scope." IE PSBT_IN_NON_WITNESS_UTXO = 0x00, PSBT_OUT_REDEEM_SCRIPT = 0x00. Presumably, the first map after the Global map is an Input map. And the last map in the transaction is an Output map. But, what about the maps in-between? How can we tell if it an input map or an output map?

James.


As an aside, I decided that I am going to configure my old Win XP, to be a duel boot with ubuntu. Sadly, the hardware does not support boot from USB and I don't own a DVD burner. So I ordered a cheap one off of ebay and will have to try to install the os after that arrives.

Thank you HCP,

I am able to follow what you are saying. However, I am still a little confused about the rest of your transaction. The specification at https://github.com/bitcoin/bips/blob/master/bip-0174.mediawiki#cite_note-6 says the PSBT should have 3 sets of key-value maps. (Global, input, and output). Your transaction appears to have 5 sets of maps.

70736274ff0100a002000000028e801dd1c31b8f6952d30ab71cb8cc2c0aed06340ad0b07f0895e8b876c829c b0000000000fdffffffde91c266e9c9a1a6d073cf5fe48253763855569fc0789e25e7f1f4ec5e06 4cf60000000000fdffffff0282839800000000001976a91407f1d4de636e42f16f49988c8dc17e9 44306d26588ac80969800000000001976a91450bac67862a3984fe72839af0f14e2ba08e6766488 ac89021d00000100df0200000001bdecc2290de66382eb8c5384f1d9c4482cfbb00c4f6db71db427105b7fa3308 d000000006a47304402200a0b02f5bc346324aedac80490af39d2d2d639e01dee391f6629b9fea9 c0891e0220754e4ee039e2cd6a483269a572ecf2cabaeec55d6b8d37e487b2e592f661bf7201210 3b0ef8a6bb035b3d710faa53dc03479ea13f724a358b35208b2c7bd8f835186fafdffffff022293 9800000000001976a914aebd0267e135531212e791eb225510be66f03cfe88ac00e1f5050000000 017a914a74bd62f91c707ea86bd70a4fab9a650639e8a38876f311b00220602636f8fefa33369d4 d2c07c07b00432ede5a155688c7b4fccda7fe845f119e74c0c6b163ff90100000022000000000100e20200000001959746d8e586847e97285ebc2f5ec2fe9e495a04fa396dd31c8e65f0a9cc43c 0000000006b483045022100875c175edebd0618155d041ac2723ecd6fc97e4d29ce1f8df5414cad 1d29501b02200745ce579fbbe5da28e838ec45330bfe53091f3074d40ae0371870c7b329d2f8012 1032a614933ee74e2dbfa8196e4c1eadca9d5a13c37760fadb91a2365199eed58eafdffffff0256 889800000000001976a9142909ed18fc26e7c67315a57a340266f48c1d454788ac8096980000000 0001976a9145e32926e03c3c26cb21ce44abca1cdb73ca77c4f88ac09041800220602029734bd50 b3af7a9f6d9710009c52f2b740b9ee5bf2251020d6126a1b8d8c380c6b163ff9010000001500000 00022020206dbf0c9c69646b18c80405e109116c434a57379b8e4fc0c273a6ece707795930c6b163ff 9010000002b000000002202033ba344a7661a33329ae181ecb34171cba5a0e56ffc03af440a134166bffbc3510c6b163ff 9000000000000000000


The first separator "ff" appears at position 8. The global map follows. The second separator "00" appears at position 336. The input map follows. The third separator "00" appears at position 886. The output map follows.

There are 2 more separators with key-value maps following. They are at position 1442 and 1540. In blue. There is a final separator at 1638 which terminates the transaction.


I also decided to look at the example I first started with. I found it contained one extra set of key-value maps.

Do you know what this extra data is used for?

Thank you,
James.

Thank you for the advice on how to extend the trial time for Windows 10. It is an interesting idea, but I think my hardware is too old to support 10.

coinmaster, unable. Please read first post in thread.


BitMaxz, your idea is very intriguing. However, I tried what you suggested and am getting an unable to parse error in 2.9.0. I am not sure what format it is expecting. I tried with Base64. Is it hex, or json? I have never used this feature before.


Maybe we can back up the discussion a little bit and you guys could help me understand the different formats we are dealing with.
Using 4.0.9 I can choose to "export", and "copy to clipboard". This gives the transaction encoded in base64? And if I choose to "export to file" that is same base64 converted to ASCII?

Is there anyway to take either of these representations of the transaction and convert it to something that is in a human readable form? I thought I could take base64 string from the clipboard and convert it to hex using:  https://cryptii.com/pipes/base64-to-hex  Then, take the hex and use a tool like https://live.blockcypher.com/btc/decodetx/ to decode the hex to a json representation of the transaction. But this does not work. I think the hex is bad, but not sure.

I used to understand how this all worked on 2.9.0, but now I am very confused.

James.

Thanks guys I appreciate the advice.

xenon, thank you for the instructions on how to circumvent the registration of Win 10. I think my hardware is probably not a good fit for Win 10, but the advice is most helpful.


I guess I am being too paranoid, but for me this is a signification amount of value I am trying to protect. My concern is a scenario where my Electrum gets compromised somehow. I had been manually verifying the transaction in the unsigned.txt file to make sure it matched what was being displayed in the Electrum GUI. I would do this before I signed the transaction and again after the transaction was signed. For the attack to be successful I know they would need to compromise both the on-line Electrum used to create the transaction and the off-line Electrum used to sign the transaction, which is unlikely.


I was unaware that the signed transaction will be exported in Base64. (I have not been able to get 4.0.9 to start yet for my offline wallet) So, at least I can still visually verify the signed transaction.


Just have 2 more questions,
1. Is there an easy way to decode the contents of the unsigned binary encoded .psbt file that does not involve using Electrum?
2. Can someone recommend an off-line utility which will decode the contents of the signed Base64 encoded .psbt file?

Thank you for helping me learn more about this.
James.  

I am sorry, but I am not understanding. If this is documented someplace, please let me know and I will research it.

I don't think Electrum is producing Base64 encoded psbt files. When I open the .psbt file I see this.

---
psbtÿ
U   
ä[J§éŽz �×U¶‚ÏÙ\¶iÁα¬�›ÂrÑÑiå     ýÿÿÿ
}
    v©™\´¢tó÷t4¦!Êd,14ê�ˆ¬
 
â
   
ÿãçæYÉ�qÇm÷Un]»:•
4wÙ:.“b:©_TÍ    kH0E! è˜+‰P»AÁk~ ­xÍý¨©¼XÑo×0ù“hx{O 0ª¶É°O   DaYYKI¬’Òt[
Ê–œx)(¼3;‰
!HÁÞô×û²0„
z4#qá)³   e~EöqØkð¤ö•/rþÿÿÿ}
    v©Z   ìqï
,òê�§xn1u_ˆ¬@Ys    v©×d�S8.Þ8WW̵FcÙ؈[Ûˆ¬É "ðÿez5ÅnÍ­,^
p'.4fýãÅÆ B�qiÄ÷¬8ˆL�ŽÐ
       "Ê[Þ²Ûñ$À©¬õ¶É\_˜6¼H¶xü̶"æÛ÷�ŽР      
---

I think this is some kind of binary version of a psbt. I am wondering if there is anyway to reverse engineer this back to an actual transaction. I tried running it through that web based utility you mentioned in your post, but it says "Forbidden character at index 4."

I think you are right about using Linux. It looks like I might be able to run Win 7 on this hardware, but it is not abandon ware yet. I am not going to try to buy it or mess with hacked versions.

Can anyone tell me anything more about how the latest release handles saving unsigned transactions to a file? I like to manually verify all the outputs in the unsigned transaction file before I allow the file to be copied to a blank thumb drive. (And then loaded on the offline wallet to be signed.)  Is there anyway to validate the contents of this file using something external to Electrum before signing the transaction? I tried to open the file but it looks like encrypted contents now. The documentation does not appear to be updated since this was changed.

At some point in the past, the unsigned transaction was saved as hex which could be decoded to json with many different utilities.

Thanks,
James.

Thank you NotATether.

I am having a hard time understanding what you are telling me. Prior to release 3.0.0, Electrum was distributed using a version of python that did run on XP? Since Electrum 3.0.0 the version of python used no longer works on XP?

Are you suggesting that I download the last version of python which supports XP and then attempt to rebuild the Electrum executable using that version of python?

I think I could upgrade the OS. The PC is from 2000. The only reason I was keeping it around was for maintaining my offline wallet.

Regards,
James.

Dear Friends,

I am hoping someone can offer some assistance. I have a number of coins that are stuck in an old wallet on a PC running Win XP.
I also am looking for some help on the transaction signing process which has not been updated in the official documentation for the current release.  

History:
Back in 2017 I created an Offline Wallet using Electrum 2.9.0. The offline PC is an old Pentium running a fresh install of 32 bit Windows XP. The PC has never been connected to the internet and has nothing installed on it except the OS and Electrum. On my newer Win 10 laptop I have my Watching Only Wallet with the public master key.

My standard process for transactions in 2017 was to;
1. Create the transaction on my Win 10 laptop using my Watching Only Wallet.
2. Save the unsigned transaction to unsigned.txt.
3. Open unsigned.txt and decode the hex to json and visually verify the outputs of the transaction.
4. Copy unsigned.txt to a thumb drive.
5. Open unsigned.txt with my Offline Wallet, sign the transaction, and save it back to the thumb drive.
6. Visually verify raw signed transaction on my laptop.  
7. Open the transaction with the Watching Only Wallet and transmit it to the network.

I kind of forgot about things for 3 years, but now I would like to use Electrum again and I am having problems. I tried to follow the same process I outlined above.

The first issue I had is that when opening the Electrum 2.9.0 Watching Only Wallet with my laptop it is unable to connect to the sever nodes. I upgraded to Electrum 4.0.9. This solved that problem. I am now able to use my Watching Only Wallet using Electrum 4.0.9. Next, I created my unsigned transaction using Electrum 4.0.9 and saved it to disk. I then tried to open the unsigned transaction file to visually verify the outputs. This did not work because the file looks like it is encrypted. Reluctantly, I assumed the transaction was correct and saved it to my thumb drive. Also, I copied Electum 4.0.9 to my thumb drive to upgrade my Offline Wallet PC so that it can read these encrypted unsigned transactions. That is about as far as I got.

On my offline PC with Windows XP os, Electrum 4.0.9 does not work. On starting Electrum I keep getting a windows alert box with "the procedure entry point _wputenv_s could not be located in the dynamic link library mscrt.dll" I did some searching and the best information I could find was that I probably needed to install the "Microsoft Visual C++ redistributable package" from https://www.microsoft.com/en-us/download/details.aspx?displaylang=en&id=29. This did not work. The package appeared to install, but I still get the same alert box when trying to start Electrum. After more investigating I noticed that Electrum 4.0.9 says it is for Windows 7 and above. I tried to use some other releases of Electrum. It looks like the oldest Elecrum release that will connect to the server nodes is 3.0.1. That version also has the same mscrt.ddl library problem when running on Win XP.

So, That is where I am at now. My questions are;
1. Does anyone know if there are any library(s) that I can install on XP that will allow me to access an old Electrum wallet that is on a Win XP machine?
2. Is there anyway to still visually verify transactions before they get moved to a Offline Wallet PC? I am very uncomfortable with copying unsigned transaction files to the offline pc if I have no idea what is inside these files. I was hoping to be able to still follow a process like I outlined above.  
3. If there is no way to run Electrum on Win XP, how should I correct this situation? Is the best process to copy the Offline Wallet from my Win XP machine and put it on my newer laptop and try to open it there with Electrum 4.0.9? (I am reluctant to loose the security of the Offline Wallet)

Thank you.
James..