I am using Qt and REST method for API calls,
I can do every call successfully.
But when I try POSTing Image on flickr. I am getting this error.

err = 100 Invalid API Key (Key not found)

I am constructing this packet manually. As there is no library available for C++.

I know that many peoples faced same problem, but they cant clearly mention the solution. They just worked on hit N trial basis and it worked for them.

This is my POST.

POST /services/upload/ HTTP/1.1
Content-Type: multipart/form-data; boundary=-----7d44e178b0434
Host: api.flickr.com
Content-Length: 15315

-------7d44e178b0434
Content-Disposition: form-data; name="api_key"

ff743da7544779780bdb279453d76880
-------7d44e178b0434
Content-Disposition: form-data; name="auth_token"

72157607108777795-54b0e5952bbb1246
-------7d44e178b0434
Content-Disposition: form-data; name="api_sig"

e8a6daa979adc84fa103564d23729c01
-------7d44e178b0434
Content-Disposition: form-data; name="photo"; filename="C:\_COSITestImageData\aaaaa.JPG"
Content-Type: image/jpeg
RAW JFIF DATA
-------7d44e178b0434--


Many others also facing same problem, you can look there also.

http://tech.groups.yahoo.com/group/y...r/message/1313


http://www.flickr.com/groups/api/dis...search=err+100


http://www.flickr.com/groups/api/dis...+api+key+found



Thanx in advance.