[GNC-dev] New OFX Requirements For USAA FSB

Scott McRae smcrae at parax.com
Sun Feb 7 22:06:29 EST 2021

>>* So I decided to give the devil his due and temporarily got a Quicken
*>>* subscription and setup an SSL man-in-the-middle.
*>Sure, you can have a man-in-the-middle setup, but if you don't have the
>keys that quicken and the bank use to communicate and communications are
>encoded, you can't get any data from being in the middle, unless I'm
>missing something.

I generated a self-signed cert and added to the trust store on my Mac OS
keychain. I was actually able to get away with a very manual man-in-the-middle
using an "openssl s_server" command running on 433, modifying the /etc/hosts
file to point back to my machine, and copy-pasting the request to curl, then
copy-pasting the response.

On Sat, Feb 6, 2021 at 8:45 PM Scott McRae <smcrae at parax.com> wrote:

> I got this working in my software with some help for the info on this
> list. Here is a write-up:
> USAA's changes to their OFX interface
> -------------------------------------
> On 2020-01-26, USAA's previous OFX interface (
> https://service2.usaa.com/ofx/OFXServlet) stopped working. It seems like
> they switched to a new interface through a tech provider to replace their
> previous login method (with your website credentials) to an app-specific ID
> and password. This is a good move for security, but it was done without
> notice, it seems, to anyone but Quicken.
> From some internet searches, I found some people on the right track to
> fixing this on the GNU Cash development mailing list:
> https://lists.gnucash.org/pipermail/gnucash-devel/2021-January/045664.html
> They were able to determine that USAA was:
>  - using a new OFX endpoint:
> https://df3cx-services.1fsapi.com/casm/usaa/access.ofx
>  - using a new OFX Org ID: USAA Federal Savings Bank
>  - using a new OFX FID: 67811
> Additionally, someone on the USAA forums was about to extract and post the
> link to generate an App ID and PIN:
> source:
> https://communities.usaa.com/t5/Finances/USAA-Creates-Quicken-Monopoly/td-p/243850/highlight/false
> Authorization link: https://df3cx-services.1fsapi.com/casm/usaa/enroll
> However, with a lot of trial and error I still wasn't able to hit this new
> endpoint successfully. So I decided to give the devil his due and
> temporarily got a Quicken subscription and setup an SSL man-in-the-middle.
> The new OFX interface is *very* finicky, so you basically have to input
> everything exactly the way it expects it. Here is an example of an account
> listing query that works:
> echo -en
> Federal Savings
> Bank\r\n<FID>67811\r\n</FI>\r\n<APPID>QMOFX\r\n<APPVER>2300\r\n<CLIENTUID>1955A543-B071-455E-A31E-73CC7C493D68\r\n</SONRQ>\r\n</SIGNONMSGSRQV1>\r\n<SIGNUPMSGSRQV1>\r\n<ACCTINFOTRNRQ>\r\n<TRNUID>e39add7d-2085-4504-b9ee-be37927de39c\r\n<ACCTINFORQ>\r\n<DTACCTUP>19900101\r\n</ACCTINFORQ>\r\n</ACCTINFOTRNRQ>\r\n</SIGNUPMSGSRQV1>\r\n</OFX>\r\n"
> | curl -isS -X POST -H "Content-Type: application/x-ofx" -A InetClntApp/3.0
> --data-binary @- https://df3cx-services.1fsapi.com/casm/usaa/access.ofx
> Note you have to change the XXXXX and NNNNN to the App ID and PIN you get
> from the link above.
> Some things I've found through trial and error:
>  - The OFX elements must be separated with "\r\n". This is dumb, but true.
> No spaces. No simple "\n". Exactly "\r\n".
>  - The APPID "QMOFX" and APPVER "QMOFX" work. Others I tried did not.
>  - The CLIENTUID "1955A543-B071-455E-A31E-73CC7C493D68" works for me. It
> must be uppercase. This might be particular to your account. If so, you can
> find it looking at the OFX logs from Quicken.
>  - TRNUID must be present, but an UUID will do.
>  - DTACCTUP: The value "19900101" works. The value "19700101" does not.
> The value "19900101000000" does not.
>  - You need the "Content-Type: application/x-ofx" header
>  - You need the User-Agent "InetClntApp/3.0". This is what Quicken for Mac
> sends.
> It also seems their gateway will under some conditions put your IP on a
> ban list. If you are testing, you may want to spin up an AWS instance or
> something. When you get on it, you'll start seeing an empty HTML page
> response, like:
> <html>
> <head>
> <META NAME="robots" CONTENT="noindex,nofollow">
> <script
> src="/_Incapsula_Resource?SWJIYLWA=5074a744e2e3d891814e9a2dace20bd4,719d34d31c8e3a6e6fffd425f7e032f3">
> </script>
> <body>
> </body></html>
> Valid queries will work from different source IPs when this happens.
> Thanks to Bob White on the GNU Cash list and RDD! on the USAA Forums for
> the breadcrumbs. No thanks to USAA for swapping out their functional
> interface with absolutely no notice or documentation and pretending like
> Quicken users are the only customers of any importance. Please just don't
> break our software again... at least for awhile.
> - Scott McRae

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