OpenSSL is an open-source implementation of the SSL and TLS protocols.

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understanding client certificate - pfx on the general

Today I am given a pfx and told to access a website. I have absolutely no idea what was given to me initially, so please kindly confirm my understanding on a general level 1) the pfx is a container ...
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1answer
42 views

Generate CSR code on local machine

I've tried activating an SSL cert. When it asked for the CSR code, I was thinking about generating this code on local machine because I haven't rented my own VPS yet. The thing is, I'm not sure ...
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1answer
109 views

Why does this key get Base64 encoded prior to use?

I wish to have my server encrypt messages to clients who have each provided the server with an RSA public key, as well as having the clients authenticate their messages to the server using their ...
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0answers
39 views

Openssl ciphers list sorting and removing

I was playing with a ciphers app to create example list of suites. Looking at the website (https://openssl.org/docs/manmaster/apps/ciphers.html) if I run one of the examples there: openssl ciphers -v ...
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2answers
844 views

How secure is AES-256-CBC with user provided password and initialization vector

From my understanding the IV is used as a previous block for the first block only. But since each block is used by the following this adds significant security is a IV is provided and not based on the ...
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2answers
211 views

Use openssl to individually verify components of a certificate chain

This is related to another question, How to verify a signature of one entity by another using OpenSSL CLI? I used openssl s_client -showcerts -connect www.google.com:443 to collect three certificates ...
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1answer
54 views

OpenSSL_encrypt returning an incorrect cyphertext?

I am trying to use the openssl_encrypt function in PHP, this is my code: <?php $message = hex2bin("00112233445566778899aabbccddeeff"); $key = hex2bin("000102030405060708090a0b0c0d0e0f"); $method =...
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1answer
39 views

table elements are not encrypted

I read a security book a while ago that said HTML table elements are sent plain text, even if the server connection is https. Is this accurate? I'm thinking about making an on-line purchase from a ...
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0answers
24 views

About DROWN SSL attack [duplicate]

I need some clarification regarding DROWN attack: 1) All and only SLLv2 is vulnerable regardless of the chipper strength? 2) How can I check it with Nmap or sslscan? 3) How it's done? I have also ...
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3answers
213 views

How to decrypt SSL traffic with a packet sniffer when I have the private key?

How you do you decrypt ssl packets (traffic) with the private key? I tried to do this with ssldump and openssl but nothing worked.
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3answers
208 views

Why doesn't openssl s_client correctly validate google.com:443?

I try $ openssl s_client -connect www.google.com:443 but it openssl complains that the cert chain is invalid: $ openssl s_client -connect www.google.com:443 CONNECTED(00000003) depth=2 C = US, O = ...
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1answer
87 views

How to verify a signature of one entity by another using OpenSSL CLI?

I'm teaching a class about certificate chains, so I download the chain from www.google.com which has 4 certs. I want to demonstrate how the dependencies work from issuer to subject by showing that ...
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5answers
2k views

Is it possible to recover a lost passphrase for a private key file?

We have a set of public and private keys and certificates on the server. The problem is that while public encryption works fine, the passphrase for the .key file got lost. So, when trying to execute ...
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0answers
163 views

MQTT (Mosquitto) certificate SSL23_GET_CLIENT_HELLO:unknown protocol [closed]

I'm been desperately trying to get my MQTT clients to connect to my MQTT broker which is set up with a certificate from a CA. To be able to get the CA certificate, I've used the letsencrypt python ...
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1answer
64 views

Is reseeding OpenSSL CSPRNG necessary if using RAND_bytes?

I read that cryprographic secure PRNG (CSPRNG) need a random seed to provide random output. Looking at OpenSSL that seems to be archived by RAND_poll() and random data is fetched with RAND_bytes(buf, ...
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2answers
115 views

How to have client encryption without server encryption key

I want to build a service where people can message each other via their mobile device so that they encrypt all of their information on their device and not on my server. Basically I want to two people ...
5
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1answer
69 views

Regenerating dhparam periodically

Does it increase connection security if I regenerate the dhparam files used with NGINX on our servers periodically e.g. every week? What issues may arise from this? Is there any benefit in doing ...
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1answer
81 views

ECDSA implicit certificate using OpenSSL

I am trying to generate implicit ECDSA certificate only for signing and verification using OpenSSL. I tried google but I am getting many research papers. I understood that A messages need to be signed ...
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1answer
117 views

CSR with only public key with openssl

So I have been doing my research and haven't found anything specific enough to my problem. As the question title states, I want to make a CSR with only the public key. What I have been able to do is ...
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1answer
3k views

How to manually test for DROWN attack?

We know that the official website serves the user with a way to test our servers against DROWN attack. Apart from that, I am looking for a manual testing method to check any servers against this ...
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3answers
130 views

Are there any problems with using CAMELLIA, IDEA and SEED based cipher suites on a web server in 2016?

I have recently seen CAMELLIA, SEED and IDEA cipher suites in use for HTTPS on a web server and am unsure what to suggest to the owner. The keys in use are all over 128 bits in length and standard ...
8
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1answer
225 views

Cache Bank conflicts and CacheBleed: What is there to worry about?

It seems that researchers have announced yet another vulnerability regarding OpenSSL, separate from the DROWN issue, called CacheBleed. You can view the research paper here. How does it work, and ...
157
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2answers
21k views

What is DROWN and how does it work?

There is a new recent attack "on TLS" named "DROWN". I understand that it appears to use bad SSLv2 requests to recover static (certificate) keys. My question is: How? How can you recover static ...
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0answers
28 views

RSA decryption with Private and Cert files

What I have : The cipher message, the plaintext message, and something that could be the RSA Private & Cert. (I can create as many couple ciphered/plaintext as I want) I would like to be able to ...
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1answer
119 views

Protect against client-initiated renegotiation DoS in OpenSSL/Python

According to https://blog.qualys.com/ssllabs/2011/10/31/tls-renegotiation-and-denial-of-service-attacks, servers supporting SSL/TLS connections and allowing client-initiated renegotiations are ...
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0answers
27 views

Finding the EMSA-PKCS1-v1_5 DigestAlgorithm field in the x509 certificate

From the RFC - https://www.ietf.org/rfc/rfc3447.txt A.2.4 RSASSA-PKCS1-v1_5 For each OID, the parameters field associated with this OID in a value of type AlgorithmIdentifier shall have a value ...
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1answer
51 views

How is hash used with AEAD-based ciphers in TLS? [duplicate]

Look at this cipher: ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(128) Mac=AEAD It uses AES-GCM for encryption and data origin authentication (according to RFC-5288), so no ...
3
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1answer
48 views

self-signed CA next to signed CA?

What I'm trying to do is implement client-certificate authentication on my website (running on Apache). From this question I understand that it's not possible to generate a client certificate myself ...
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0answers
37 views

Followup to one-liner to create cert request with SAN

I've been trying to use the OpenSSL line from this older thread to create a CSR with subject alternative name: Provide subjectAltName to openssl directly on command line If I run the line from that ...
1
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1answer
95 views

Is there any way or tool to check whether a particular iOS app is implementing SSL Pinning functionality?

I'm just learning the iOS security. This is completely a beginner question. I'm trying to figure out whether there is any particular way to check if an iOS app is implementing SSL Pinning ...
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0answers
238 views

How does openssl pkcs12 command work?

I have been using certutil dump command successfully to check the order of pfx certificate chain. Recently I tried doing the same using openssl pkcs12 command and it give me exactly the opposite order ...
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1answer
75 views

Is OpenSSL generating Diffie-Hellman parameters that are safe for use in TLS or SSH servers?

I would like to generate Diffie-Hellman parameters on a Debian GNU/Linux "Jessie" 8 with OpenSSL. Lets assume the system CSPRNG was seeded with some real random data. On such a system, is the result ...
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1answer
36 views

Diffie Hellman prime attributes

If I generate a Diffie-Hellman prime openssl dhparam 512 -text (deliberately of small size to keep the paste size below small; I know minimum is 2048 and up), what are the different parts of the ...
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0answers
52 views

Log to file my own SSL traffic coming from websocket

I have to decode and capture my own traffic that come from a websocket WSS listening on port 7072, when I use browser to connect to my data provider. My idea is: to redirect traffic to serverpush....
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2answers
116 views

sharing private key sTunnel

All of the sTunnel guides and implementations at work do the same thing, they say once the private key and the public cert are created on the server, you need to cat them together and then share with ...
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1answer
88 views

OpenSSL key derivation

I'm trying to manually decrypt DTLS packets sent by OpenSSL. The cipher suite used between the server and the client is TLS_RSA_WITH_AES_256_CBC_SHA256 and my understanding is that the IV used by ...
4
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1answer
386 views

What are the main advantages of using LibreSSL in favor of OpenSSL

What are the main advantages of using LibreSSL vs OpenSSL? As I understood LibreSSL is a fork of OpenSSL: LibreSSL is a version of the TLS/crypto stack forked from OpenSSL in 2014, with goals of ...
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2answers
110 views

Banner grabbing OpenSSL versions with OpenSSL

With the recent news about a new OpenSSL vulnerability (affecting 1.0.2 only), I'm looking to conduct some research and I was wondering if there was an way to identify what version of OpenSSL a server ...
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0answers
69 views

How to convert the PRIVATEKEYBLOB structure generated using CryptExportKey to bigendian?

Private-key BLOBs, type PRIVATEKEYBLOB, are used to store private keys outside a CSP. Extended provider private-key BLOBs have the following format. PUBLICKEYSTRUC publickeystruc; RSAPUBKEY ...
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2answers
112 views

what is the different between X.509 certificate and 2-way SSL? or both are same? [duplicate]

Can anyone clarify what is the difference between an X509 certificate and two-way SSL? or both are same?
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1answer
89 views

Server providing two different SSL certificates

When I check on browser for a site example.com, I see that site has a valid certificate, not expired, with validity till end of 2016. At the same time, When I scan for the same domain on the port 443 ...
3
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1answer
66 views

SSL Labs report question: Is “Insecure Renegotiation” possible if weak cipher suites are not available on server?

On one server, we have removed weak cipher suites and insecure protocols to try to pass SSLScan / SSL Labs. One outstanding problem is Insecure Renegotiation. I read that: The Apache Software ...
0
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1answer
171 views

Is it possible to create a pem file server certificate from the result of openssl s_client -showcerts?

I know it is possible to list server certificates from a client via openssl s_client -showcerts. So, my question is, is it possible to create a valid ssl server certificate from this without needing ...
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2answers
44 views

How to avoid writing .pem while signing a csr?

I am using following command to sign a certificate, openssl ca \ -in client.csr \ -keyfile server.key \ -cert server.crt \ -outdir ./some_dir \ ...
0
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1answer
79 views

OpenSSL gmail - receiving Please log in via your web browser and then try again

Using openssl as below when I do EHLO auth login and then enter my username and password I get the following error: Please log in via your web browser and then try again. Learn ...
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1answer
100 views

Where in the CSR is the public key?

I am reading http://www.akadia.com/services/ssh_test_certificate.html In step 2 openssl req -new -key server.key -out server.csr server.key is generated earlier using openssl genrsa -des3 -out ...
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0answers
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Why does SubjectAltName not turn up in my CSR?

Does the CSR generated contains the SubjectAltName I have configured the openssl.cnf file to support extensions and when i dump the CSR i can see subject is available not the SubjectAltName This is ...
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2answers
231 views

With openssl des3, what are the passphrase parameters?

I'm using OpenSSL's des3 tool to encrypt a file, e.g. openssl des3 -salt -k SUPER_SECURE_PASSPHRASE < inputFile > outputFile Everything's working, but now I have to choose a final, fixed ...
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1answer
101 views

How do I change LUKS backend to OpenSSL?

I know there is a way to do it, but I don't know how to do it: the default backend for LUKS is libgcrypt and I want to test it with the openssl cryptographic library. I was told that there is a ...
5
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1answer
81 views

Why is the Key Derivation Function important?

Let's consider this openssl command : openssl enc -aes-256-cbc -pass pass:PASSWORD Why is it important to have a good Key Derivation Function? This answer to another question suggest that GnuPG is ...