Created attachment 947290 [details]
Script to reproduce the problem

Description of problem:

A python script using pycurl running on RHEL7 is behaving differently from RHEL6. The same script works fine on Mac OS X and Debian, including RHEL6 and CentOS6.

The pycurl version is exactly the same in RHEL6, RHEL7, Debian and MacOS.

During a post containing urlencode version of a base64 (SSH key), a strange binary is sent under RHEL7, while a standard HTTP post is performed under RHEL6.

The included script is a reduced version of a bigger component (securepass-tools) to reproduce the problem.

Version-Release number of selected component (if applicable):
pip version -> pycurl (7.19.0)
RPM -> python-pycurl-7.19.0-17.el7.x86_64

How reproducible:
Always on RHEL7
Works on RHEL6, MacOS and Debian

Steps to Reproduce:
1. use nc -l 5000 to simulate a web server
2. Execute the included script (or optionally available on https://gist.github.com/gpaterno/8eae080e4d5d33970876)
3. See the strange result

Actual results:
POST /test/ HTTP/1.1
User-Agent: PycURL/7.29.0
Host: localhost:5000
Accept: */*
Content-Length: 438
Content-Type: application/x-www-form-urlencoded

??????8??????????A`??????@??p?????з?1??.?6zoK5D2T1??.?X8COpdH51??.?z%2FFP3X1??.?Evw%3D%31


Expected results:
POST /test/ HTTP/1.1
User-Agent: PycURL/7.24.0
Host: localhost:5000
Accept: */*
Content-Length: 438
Content-Type: application/x-www-form-urlencoded

USERNAME=foobar&ATTRIBUTE=sshkey&VALUE=ssh-rsa+AADDB3NzaC1yc2EAAAABIwAAAQEA6ezbY7Pb9Ld2fRRgIzEaQln66HgJL0MkHPv7fYsU3Eo%2B8F5gC%2BgY4nbxCCuvvJ652WltW786Es1kduWpT13gKkT2TCqvXhC%2BTDbml5Rp9ECvrSs4Xlc2nYQb%2BMVwbEnnu3c92WaXs4q4Sjj2lTAAo6ftsjT00uqWUbjX1NoshnH9mo34NCnI2XniI50dNfDx4VxMK5ZRn6zoK5D2T9bKEsAHsmQpNKo9ySKai4SMVP%2FGnhAhyjLQtq5X8COpdH5AUJy4RHYyL0upF0ClvWYnLpPZuPajsoOZgruu3OQz%2FFP3XsosMZ04ZNL84mSDSBKE%2F6N2DMBxw9tl4cuHRx1Evw%3D%3D+


Additional info:
Note that the payload is actually a form of binary.