TL;DR I'm trying to reach an URI which only takes SSLv3. If I try to access it with curl or Python requests (which uses the ssl module) it doesn't work (different errors).

Some longer explanation

There's this API who has this URI: https://api.mercadolibre.com/sites/MLA/search?q=ipod

  1. If I try to access that URI with the browser, it works fine (Chrome and FF).

  2. If I try to curl it: curl -Iv https://api.mercadolibre.com/sites/MLA/search?q=ipod it doesn't work. The error returned is:

    curl: (35) Unknown SSL protocol error in connection to api.mercadolibre.com:443
  3. Forcing curl to use SSLv3 works fine:

    curl --sslv3 -Iv https://api.mercadolibre.com/sites/MLA/search?q=ipod
  4. openssl s_client -connect api.mercadolibre.com:443

    answers with:

    no peer certificate available
    No client certificate CA names sent
    SSL handshake has read 0 bytes and written 305 bytes
    New, (NONE), Cipher is (NONE)
    Secure Renegotiation IS NOT supported
    Compression: NONE
    Expansion: NONE

How can it be possible that the browser is connecting Ok and curl and Python are not? How should I fix this? Is this even my problem (or the owner of the API)?

Info about my system

  • Ubuntu 14.04
  • OpenSSL 1.0.1f 6 Jan 2014
  • 2
    That site's SSL setup is horribly broken. They need to fix it as soon as possible. Aug 26, 2014 at 20:08
  • Well. That's a relief. But, does it has anything to do with my issue? Aug 26, 2014 at 20:12
  • Most likely. As you can see, many browsers would be unable to connect to it at all. The same is true of non-browser user agents such as curl. Not to mention the encryption is so weak that my sister could break it. Aug 26, 2014 at 20:13
  • Reading the "Handshake Simulation" section on that report seems like "OpenSSL 1.0.1h" fails with "Protocol or cipher suite mismatch". Aug 26, 2014 at 20:13
  • Yeah. Thank you very much Michael. I know someone there, I'll ping them. Do you want to create an answer for posterity? Aug 26, 2014 at 20:14

1 Answer 1


At the time this question was asked, the site in question supported only a small selection of very weak cipher suites and had very little compatibility with modern user agents. Thus it was impossible for most browsers or even robots to negotiate a connection, let alone a secure one.

The site has been (mostly) fixed since; while it still has weak cipher suites and other problems, it should at least be functional.

  • Yes. True. I reported it at the time and they fixed it. Your answer provides a great summary of the issue. Thanks! Jun 11, 2015 at 1:29

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