HTTP request failing – but only when run through Cocoapods - ruby

Question

I publish a pod with the following spec:
Pod::Spec.new do |s|
s.name = "AirTurnInterface"
s.version = "4.7.0-b.6"
s.summary = "snip"
s.description = "snip"
s.license = { :file => 'LICENSE', :type => 'AirTurn' }
s.homepage = "snip"
s.author = { "Nick Brook" => "snip#airturn.com" }
s.ios.deployment_target = "11.0"
s.frameworks = 'CoreBluetooth', 'GameController', 'Security', 'UIKit'
s.source = { :http => "https://airturn.com/framework/test/AirTurnInterface.#{s.version}.zip" }
s.vendored_frameworks = "Framework-dynamic/AirTurnInterface.xcframework"
end
This can be tested by putting the following in a file named test.podspec and running pod spec lint test.podspec.
Until recently, this worked fine. Now, running pod spec lint fails when downloading the zip with the error:
curl: (92) HTTP/2 stream 0 was not closed cleanly: PROTOCOL_ERROR (err 1)
It also provides the curl command used:
/opt/homebrew/opt/curl/bin/curl -f -L -o /var/folders/9j/jqc5qhp922b7c8jhrvkh7h8m0000gn/T/d20221021-48752-1fqts5p/file.zip https://airturn.com/framework/test/AirTurnInterface.4.7.0-b.6.zip --create-dirs --netrc-optional --retry 2 -A 'CocoaPods/1.11.3 cocoapods-downloader/1.5.1'
The strange thing is, this command works when run directly, it only fails when run from Cocoapods (ruby). I've also tried just performing the command from a simple ruby script, which works fine. Something about Cocoapods is causing the command to fail. I've modified Cocoapods (gems/cocoapods-downloader-1.5.1/lib/cocoapods-downloader/http.rb) to pass -v to curl, which provides the following output:
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* Trying 35.209.185.188:443...
* Connected to airturn.com (35.209.185.188) port 443 (#0)
* ALPN: offers h2
* ALPN: offers http/1.1
} [5 bytes data]
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* TLSv1.3 (IN), TLS handshake, Server hello (2):
{ [88 bytes data]
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
} [1 bytes data]
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
} [512 bytes data]
* TLSv1.3 (IN), TLS handshake, Server hello (2):
{ [187 bytes data]
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
{ [19 bytes data]
* TLSv1.3 (IN), TLS handshake, Certificate (11):
{ [4039 bytes data]
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
{ [264 bytes data]
* TLSv1.3 (IN), TLS handshake, Finished (20):
{ [52 bytes data]
* TLSv1.3 (OUT), TLS handshake, Finished (20):
} [52 bytes data]
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384
* ALPN: server accepted h2
* Server certificate:
* subject: CN=*.airturn.com
* start date: Oct 5 00:07:55 2022 GMT
* expire date: Jan 3 00:07:54 2023 GMT
* subjectAltName: host "airturn.com" matched cert's "airturn.com"
* issuer: C=US; O=Let's Encrypt; CN=R3
* SSL certificate verify ok.
* Using HTTP2, server supports multiplexing
* Copying HTTP/2 data in stream buffer to connection buffer after upgrade: len=0
} [5 bytes data]
* h2h3 [:method: GET]
* h2h3 [:path: /framework/test/AirTurnInterface.4.7.0-b.6.zip]
* h2h3 [:scheme: https]
* h2h3 [:authority: airturn.com]
* h2h3 [user-agent: 'CocoaPods/1.11.3 cocoapods-downloader/1.5.1']
* h2h3 [accept: */*]
* Using Stream ID: 1 (easy handle 0x15580f600)
} [5 bytes data]
> GET /framework/test/AirTurnInterface.4.7.0-b.6.zip HTTP/2
> Host: airturn.com
> user-agent: 'CocoaPods/1.11.3 cocoapods-downloader/1.5.1'
> accept: */*
>
{ [5 bytes data]
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
{ [265 bytes data]
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
{ [265 bytes data]
* old SSL session ID is stale, removing
{ [5 bytes data]
* Connection state changed (MAX_CONCURRENT_STREAMS == 128)!
} [5 bytes data]
* HTTP/2 stream 0 was not closed cleanly: PROTOCOL_ERROR (err 1)
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
* Connection #0 to host airturn.com left intact
curl: (92) HTTP/2 stream 0 was not closed cleanly: PROTOCOL_ERROR (err 1)
Forcing http1.1 with --http1.1 doesn't help:
curl: (52) Empty reply from server
I don't know what to try next to debug further!

Answer 1

It looks like the ZIP file is being returned using HTTP/1.1 instead of HTTP/2 which CocoaPods is requiring. Older versions of TLS are no longer supported on some platforms so I'd recommend updating your web server/host to a platform that is using a more modern TLS.