[gdal-dev] /vsicurl, curl and wget

[Andrew C Aitchison]

On Sat, 25 Apr 2026, Scott via gdal-dev wrote:

> So, it works on Amazon Linux 2
> gdal 3.13.0, curl 8.3.0
>
> But not Debian 12
> gdal 3.13.0, curl 7.88.1

That is an older curl: Ubuntu have been shipping curl 8 for at least two years.

> The 403, if the one machine was blocked (why would it), wget shouldn't work, 
> but it does.

On Ubuntu 26.04, curl 8.18.0-1ubuntu2 and gdal 3.13.0
(curl from system, gdal self-compiled):

gdal vector info
     /vsizip/vsicurl/https://www.fema.gov/about/reports-and-data/openfema/cl2024_v1.gdb.zip
works and so does
curl
    https://www.fema.gov/about/reports-and-data/openfema/cl2024_v1.gdb.zip -o stf.gdb.zip

   ----

One possible difference might be which ciphers are supported.
  	openssl s_client -connect www.fema.gov:https
gives me:
No client certificate CA names sent
Peer signing digest: SHA256
Peer signature type: rsa_pss_rsae_sha256
Peer Temp Key: X25519, 253 bits
---
SSL handshake has read 4827 bytes and written 1634 bytes
Verification: OK
---
New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384
Protocol: TLSv1.3
Server public key is 2048 bit


> On 4/25/26 01:27, Laurențiu Nicola via gdal-dev wrote:
>> gdal vector info 
>> /vsizip/vsicurl/https://www.fema.gov/about/reports-and-data/openfema/cl2024_v1.gdb.zip 
>> works for me (GDAL 3.12.3), but takes a couple of minutes, because ZIP 
>> isn't great at random access. I actually cancelled it after it printed the 
>> name of the third layer.
>> 
>> HTTP 403 is "Forbidden", which is.. interesting.
>> 
>> Laurentiu
>> 
>> On Sat, Apr 25, 2026, at 04:52, Scott via gdal-dev wrote:
>>> Greetings!
>>> 
>>> I'm having issues with a remote file. The following do not work:
>>> 
>>> gdal vsi copy
>>> https://www.fema.gov/about/reports-and-data/openfema/cl2024_v1.gdb.zip .
>>> gdal vector info
>>> /vsizip/vsicurl/https://www.fema.gov/about/reports-and-data/openfema/cl2024_v1.gdb.zip
>>> curl
>>> https://www.fema.gov/about/reports-and-data/openfema/cl2024_v1.gdb.zip
>>> -o stf.gdb.zip
>>> 
>>> All result in a 403, since they're dependent on curl.
>>> 
>>> However, the following 'wget' works fine:
>>> 
>>> wget 
>>> https://www.fema.gov/about/reports-and-data/openfema/cl2024_v1.gdb.zip
>>> 
>>> Has anyone encountered this before? What am I missing?
>>> 
>>> Thanks!
>>> Scott

-- 
Andrew C. Aitchison                      Kendal, UK
                     andrew at aitchison.me.uk