Verify your SSL, TLS & Ciphers implementation. SSL verification is necessary to ensure your certificate parameters are displayed as expected. There are multiple ways to check SSL certificate, however testing through online tool provides you much useful information listed below. This also helps you in finding any issues in advance instead of user complaining about them. Note 6: A Server that does not support TLS 1.1 and TLS 1.2 that connects to another site as a Client can support TLS 1.1 and TLS 1.2 by enabling it through the Internet Options in IE. Browse to Tools > Internet Options > Advanced.Under the Security section, you would see the list of SSL Protocols supported by IE.Tick the necessary boxes. You can check the guidelines found here for more. Your SSL client is Bad. Check out the sections below for information about the SSL/TLS client you used to render this page. Yeah, we really mean 'TLS', not 'SSL'. Anybody on a mac or iphone know of a working tls 1.2 browser? Ive tried safari, firefox and chrome. We will be cut off from transactions on june 15. If Configuration Manager client does not communicate with site role endpoints (such as distribution points, management points, and state migration points), verify that Windows has been updated to support TLS 1.2 for client-server communication by using WinHTTP.
Active11 months ago
I'm trying to bring an old TLS 1.0 implementation (that I did not write) up to date to speak TLS 1.2.
As a first step I integrated the TLS 1.1 change of putting the plaintext initialization vector in the record. That was no problem. It seemed to work well enough that I could read
https://example.com
in TLS 1.1, as well as SSL Labs viewMyClient.html.Then I adapted to the TLS 1.2 change of the pseudorandom function to (for most practical purposes) P_SHA256 instead of the (more complex and bizarre) half and half MD5/SHA1 rigamarole. I did it wrong the first time and got an invalid MAC error, but it was more or less a typo on my part and I fixed it. Then the invalid MAC error went away.
But despite that, after sending the ClientKeyExchange->ChangeCipherSpec messages, I'm getting a 'Decrypt Error' back from the server(s) (same Alert regardless,
https://google.com
or anything I try). I gather the ChangeCipherSpec message is encrypting just one byte, putting it into a message with padding and the MAC, etc.If I tweak the MAC randomly by one byte, it goes back to complaining about invalid MAC. What confuses me is that the MAC itself is encrypted as part of GenericBlockCipher:
UPDATE: FWIW, I've added a Wireshark log of the failing 1.2 read of
https://example.com
, as well as a log of a functioning 1.1 session running what is the same code, not counting the P_SHA256 MAC update:http://hostilefork.com/media/shared/stackoverflow/example-com-tls-1.2.pcapng (fails) http://hostilefork.com/media/shared/stackoverflow/example-com-tls-1.1.pcapng (succeeds)
So, what exactly is it having trouble decrypting? The padding seems correct, as if add or subtract 1 to the byte I get an invalid MAC error. (The spec says 'The receiver MUST check this padding and MUST use the bad_record_mac alert to indicate padding errors.', so that is to be expected.) If I corrupt the client-iv in the message from what I used to encrypt (just put a bad byte in the transmitted version), doing so also gives me Bad Record MAC. I'd expect that to wreck the decryption also.
So I'm puzzled on what could be the problem:
- The server demonstrates discernment of valid MAC vs. not, so it must have decrypted. How's it getting the right MAC -and- having a decrypt error?
- Cipher suite is an old one (TLS_RSA_WITH_AES_256_CBC_SHA) but I'm just tackling one issue at a time..and if I'm not mistaken, that shouldn't matter.
Does anyone with relevant experience have a theory of how TLS 1.2 could throw a wrench into code that otherwise works in TLS 1.1?(Perhaps someone who's done a similar updating to a codebase, and had to change more than the two things I've changed to get it working?) Am I missing another crucial technical change? What recourse do I have to find out what is making the server unhappy?
HostileFork
HostileForkHostileFork26k77 gold badges8181 silver badges137137 bronze badges
2 Answers
Check Browser For Tls 1.2
There's actually not anything wrong with the
ChangeCipherSpec
message. It's actually the Finished
message that has the problem. It is complaining about the decrypted verify_data
Ms lync client for mac. inside that message, which is not matching an expected hash (despite the encryption/decryption itself being correct).But what's confusing in the Wireshark log is that the
Finished
message shows up on the same log line, but under the name 'EncryptedHandshakeMessage
' This makes it look like some kind of tag or label describing ChangeCipherSpec, but it's not. That message actually isn't encrypted at all.From the second link:
In practice, you will see unencrypted Client Hello, Server Hello, Certificate, Server Key Exchange, Certificate Request, Certificate Verify and Client Key Exchange messages. The Finished handshake message is encrypted since it occurs after the Change Cipher Spec message.
'Hoping someone has experience updating TLS 1.0 or 1.1 to 1.2, and might have seen a similar problem due to not changing more than the P_SHA256 MAC and bumping the version number'
They only mention two of the three places that you need to update the MD5/SHA1 combination in the 'changes from TLS 1.1' section of RFC 5246:
- The MD5/SHA-1 combination in the pseudorandom function (PRF) has been replaced with cipher-suite-specified PRFs. All cipher suites in this document use P_SHA256.
- The MD5/SHA-1 combination in the digitally-signed element has been replaced with a single hash. Signed elements now include a field that explicitly specifies the hash algorithm used.
(Note: The second applies to certificates, and if you haven't gotten to certificate checking you wouldn't be at that point yet.)
What they don't mention in that section is the third place the MD5/SHA-1 combination changes, which is a hash used in the seed for the
verify_data
of the Finished
message. However, this point is also a change from TLS 1.1, described much further down the document in section 7.4.9:'Hash denotes a Hash of the handshake messages. For the PRF defined in Section 5, the Hash MUST be the Hash used as the basis for the PRF. Any cipher suite which defines a different PRF MUST also define the Hash to use in the Finished computation.'
Check My Client For Tls 1.2 Mac
For a formal spec they're being a bit vague on 'hash used as the basis for the PRF' (is it the HMAC or just the plain hash?) But it's the plain hash. So SHA256, unless the cipher suite's spec says otherwise.
(Note also the cipher suite can dictate the length of the verify_data as more than 12 bytes, though none mentioned in the spec do so.) What is the best remote desktop app for mac.
'What recourse do I have to find out what is making the server unhappy?'
YMMV. But what I did was just build OpenSSL as a static debug library, and linked it to a simple server. Then I added breakpoints and instrumentation to see what it was upset about. (GDB wasn't letting me step into the shared library, for some reason.)
Circa 30-Sep-2018, on a plain linux machine:
git://git.openssl.org/openssl.git
./config no-shared no-asm -g3 -O0 -fno-omit-frame-pointer -fno-inline-functions no-ssl2 no-ssl3
make
The simple server I used came from Simple TLS Server. Compile against the static library with:
gcc -g -O0 simple.c -o simple -lssl -lcrypto -ldl -lpthread
I followed the instructions for generating certificates here, but changed the AAs to
localhost
Then I changed the
cert.pem => rootCA.pem
and key.pem => rootCA.key
in the simple server code. I was able to do:And successfully get back
HostileForkHostileForktest
as a response. So then it was just a matter of seeing where my client caused a failure.26k77 gold badges8181 silver badges137137 bronze badges
I can think of 2 different situations that creates this problem:
- Sending incorrect
IV
.IV
affects only 1st block in decryption ofCBC
mode, so if your content is more than 16 bytes (AES
block size),MAC
part of your data will be decrypted correctly. - If you are using incorrect padding structure, you may get error in decryption(because padding verification fails), but content will be decrypted correctly.
3,46011 gold badge77 silver badges2727 bronze badges
Not the answer you're looking for? Browse other questions tagged sslencryptiontls1.2 or ask your own question.
Active9 months ago
I want to know whether my browser is using SSL or TLS connection if I see HTTPS.
I want to know for IE, Firefox, Chrome and Safari. I want to know the protocol version.
zhtwayzhtway
4 Answers
There are several protocol versions : SSL 2.0, SSL 3.0, TLS 1.0, TLS 1.1 and TLS 1.2. Internally, TLS 1.0/1.1/1.2 are SSL 3.1/3.2/3.3 respectively (the protocol name was changed when SSL became a standard). I assume that you want to know the exact protocol version that your browser is using.
According to what is described on this blog post, Internet Explorer can display the protocol version information. Just hit File->Properties or Right-click -> Properties, and a window would open, under Connection, you'd see something like:
TLS 1.2, RC4 with 128 bit encryption (High); RSA with 2048 bit exchange
As of today, Firefox supports TLS 1.0, TLS 1.1 and TLS 1.2. You can see the negotiated protocol version if you click the padlock icon (on the left of the URL), then More Information and then under the Technical Details.
Chrome can display the version. Click on the padlock icon; a popup appears, which contains some details, including the protocol version. example: (verified on version 21.0.1180.82)
The connection uses TLS 1.0
Opera shows the protocol version in a way similar to Chrome: click on the padlock icon, then click on the 'Details' button. e.g. (verified on version 12.01):
TLS v1.0 256 bit AES (1024 bit DHE_RSA/SHA)
For browsers which do not show the information, you can always obtain it running a network analyzer like Wireshark or Network Monitor: they will happily parse the public headers of the SSL/TLS packets, and show you the version (indeed, all of the data transfers in SSL/TLS are done in individual 'records' and the 5-byte header of each record begins with the protocol version over two bytes).
And, of course, the actual protocol version is a choice of the server, based on what the server is configured to accept and the maximum version announced by the client. If the server is configured to do TLS 1.0 only then any connection which actually happens will use TLS 1.0, necessarily.
(Edit: I have incorporated some information from the comments; done a few tests myself. Feel free to enhance this answer as needed.)
Thomas PorninThomas Pornin![1.2 1.2](/uploads/1/2/6/3/126385418/878073560.png)
294k5252 gold badges699699 silver badges899899 bronze badges
Google Chrome
- Click on the padlock at the left of the address bar
Mozilla Firefox
- Click on the padlock at the left of the address bar
- Then click 'more information'
Internet Explorer
The padlock is to the right of the address bar, but it won't help. Instead
- (On a blank bit of the page) right click
- Properties
It would be neat if Internet Explorer were consistent with the other browsers. Under the padlock indicator is sensible place to look.
Colonel PanicColonel Panic1,69111 gold badge1616 silver badges2121 bronze badges
From Google Chrome version 56 up Vmware horizon client for mac.
Open Chrome developer tools using F12 shortcut key and select Security tab that would provide the security info as shown below.
DijkgraafDijkgraaf
Do I Have Tls 1.2
I am still unable to find add-ons or extensions to check ssl protocol version directly from browser session. But what I found is here.
Hacked client for mac. openssl command give ssl information.I don't know much detail on openssl command.
This site use openssl to get extensive information.http://www.serversniff.net/sslcheck.php
zhtwayzhtway
![Tls Tls](/uploads/1/2/6/3/126385418/665676901.jpg)