Old School Assistance Requested to Do POTS File Transfers

[Macknak]

After about 6 hours of non productive Google searches we pose the following question for assistance.

Thanks in advance.

We use MacBooks Pros running Yosemite and have recently decided we need to do file transfers (probably only pdf and def NOT fax protocol) between two machines USING DIAL UP POTS lines. This is a security concern and broadband connection approach is NOT an option.

We did this all the time (20 yrs ago) but we are struggling to do it now!

Here's what we have figured out we know (OR DON'T KNOW) so far:
1. We can use the USRobotics 5637 USB modem with Yosemite
2. Not sure what application we can use to dial up and connect and transfer the files (used to use ProComm or other Terminal program).


Any thoughts or suggestions on how to do these file transfers?

Thanks!

 

[case2001]

Old School Assistance Requested to Do POTS File Transfers

I know you said broadband is not an option. But why don't you just send it encrypted? It would eliminate a lot of headache. And if security is a concern couldn't a POTS line be tapped?

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Try Googling "FreeBSD cu" or "Mac OS X cu"

 

[2984839]

I'm not sure I follow here. Do you need to use dial-up because that's all you have available, or are you choosing to use it because you think it offers a security advantage?


If the latter, I would not bother with dial-up and would use an SSH based solution such as SFTP or SCP. With the defaults, it is secure enough so as to not be the weak link in your system. Without encryption, you have little to no security during transit regardless of the connection. You could also transfer the files via USB if they're really really sensitive and you don't trust SSH for some reason. A third option is to encrypt the files themselves, then send them however you wish.

 

[yjchua95]

After about 6 hours of non productive Google searches we pose the following question for assistance.

Thanks in advance.

We use MacBooks Pros running Yosemite and have recently decided we need to do file transfers (probably only pdf and def NOT fax protocol) between two machines USING DIAL UP POTS lines. This is a security concern and broadband connection approach is NOT an option.

We did this all the time (20 yrs ago) but we are struggling to do it now!

Here's what we have figured out we know (OR DON'T KNOW) so far:
1. We can use the USRobotics 5637 USB modem with Yosemite
2. Not sure what application we can use to dial up and connect and transfer the files (used to use ProComm or other Terminal program).


Any thoughts or suggestions on how to do these file transfers?

Thanks!

Just encrypt the damn thing by creating an AES-256 DMG with a long password, put the files in it, and send it off over sFTP, SSH, or even plain old Dropbox.

Not even the NSA can crack AES-256.

 

[case2001]

Just encrypt the damn thing by creating an AES-256 DMG with a long password, put the files in it, and send it off over sFTP, SSH, or even plain old Dropbox.

Not even the NSA can crack AES-256.

Or can they??????......Hahahah!!!

But I agree with you. Just encrypt it. Done. If your worried about government agency why in the world would you ask on a forum?

 

[maflynn]

Would DSL be an option, since it operates on the same copper wire?

I agree with the others, encryption is the better option then trying to setup a dial-up connection.

 

[case2001]

I guess shortly after they posted this a knock came at the front door ......

 

[jhorsman]

I actually registered so I can answer this since this is a legit need. (Your Net Goes down. POTS is a viable back door for DR reasons..) You got a couple of options here.. First and Foremost. You need to decide how you want the back end to be. I am going to assume IP over PPP links. So your receiving host will have to be configured first.. (Windows, Linux, Etc.) I am going to go ahead and say linux since it is free.

Check here for a viable way of setting it up.

https://www.howtoforge.com/linux_dialin_server

Then it will assign you an IP address. Now if you want the same host to do file shares, put the share on that server.

Next. Set up your Mac as a PPP Dialer.

https://support.apple.com/en-us/HT2399

https://support.apple.com/kb/PH18530?locale=en_US


Mount Share. Drag and Drop your File to the Server Share. Done.

That is the *Easiest* way.. Now if you want a BBS (Old Retired SysOp of WildCatBBS.) Then you want a good term program and make sure it supports zmodem protocol and get a Term Program.. Other then that.. Should still be out of the box mac side. As for BBS Software.. Well. Search around.

Edit: I saw it mentioned mac to mac.. I do not have a modem laying around to see if I can finagle a mac to mac connection.. I see some ways.. But this will require some Terminal-Fu. But I will say this much.. We have VM's and Hypervisors do Support USB Passthrough. It can always overcome a weakness one OS has to another. Also makes a nice security boundary while at it.

Also went fishing since I got curious... Looks like a mac can do pppd and chat and set ttys for dial in. See the following from Terminal:

"man pppd" has mention of setting up dial in and the config options.
"man chat" for chat scripts
I am also going to throw in the BSD manual since OS X has getty as well. See /etc/tty for configuration info (Now if it can see your modem as a /dev/ device is another story..)
https://www.freebsd.org/doc/handbook/dialup.html

Nothing really OOB.

 

[orangezorki]

What you're sending we don't need to know - we might be curious, but that's not the point.

We would be more helpful if you said, even cryptically, why you are going after a decades old and very slow transfer method. How about:

An encrpyted VPN?
The dark net? Unless you are doing something nasty, which I'm sure you're not, might be the first legitimate use for the bloody thing!
Posting encrypted physical media?
Getting a trusted employee or friend or yourself to take that media yourself? Unless you are so afraid of personal security travelling with the data, that would be the safest.