Questions tagged [openssl]
OpenSSL is an open-source implementation of basic cryptographic primitives, X.509 certificate utilities, and SSL and TLS protocols.
179
questions
56
votes
2
answers
79k
views
Decrypting TLS in Wireshark when using DHE_RSA ciphersuites
How can I decrypt TLS messages when an ephemeral Diffie-Hellman ciphersuite is used? I am able to expose the premaster secret and master secret from the SSL Client. Using that, how to decrypt the ...
- 811
248
votes
4
answers
112k
views
SSL3 "POODLE" Vulnerability
Canonical question regarding the recently disclosed padding oracle vulnerability in SSL v3. Other identical or significantly similar questions should be closed as a duplicate of this one.
What is the ...
- 82.9k
58
votes
2
answers
8k
views
What should end-users do about Heartbleed?
What should a website operator do about the Heartbleed OpenSSL exploit? mainly talks about what people running websites should do about Heartbleed.
What should end-users of websites be doing?
Do ...
- 2,100
48
votes
5
answers
68k
views
openssl: recover key and IV by passphrase
A large amount of files were encrypted by
openssl enc -aes-256-cbc -pass pass:MYPASSWORD
Openssl should derive key+IV from passphrase. I'd like to know key+IV equivalent of that MYPASSWORD. Is ...
30
votes
5
answers
62k
views
Missing X509 extensions with an openssl-generated certificate
My goal is to create a certificate with opensslsimilar to this one generated with cfssl
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
60:44:dc:0d:80:f4:54:55:e8:...
user15194
281
votes
18
answers
473k
views
Provide subjectAltName to openssl directly on the command line
Is it possible to provide a subjectAltName-Extension to the openssl req module directly on the command line?
I know it's possible via a openssl.cnf file, but that's not really elegant for batch-...
- 2,943
227
votes
1
answer
91k
views
How exactly does the OpenSSL TLS heartbeat (Heartbleed) exploit work?
I've been hearing more about the OpenSSL Heartbleed attack, which exploits some flaw in the heartbeat step of TLS. If you haven't heard of it, it allows people to:
Steal OpenSSL private keys
Steal ...
user43639
115
votes
5
answers
57k
views
What should a website operator do about the Heartbleed OpenSSL exploit?
CVE-2014-0160
http://heartbleed.com
This is supposed to be a canonical question on dealing with the Heartbeat exploit.
I run an Apache web server with OpenSSL, as well as a few other utilities ...
- 5,337
260
votes
11
answers
38k
views
How to explain Heartbleed without technical terms?
Most of my friends who are not experienced in computers want to know what Heartbleed is and how it works. How would one explain Heartbleed to someone without a technical background?
- 3,233
29
votes
2
answers
44k
views
SSL certificates and cipher suites correspondence
I have been learning about the SSL/TLS protocol (from https://www.rfc-editor.org/rfc/rfc5246) and have a few conceptual questions about the protocol.
The client and server exchange "hello" ...
- 391
61
votes
2
answers
23k
views
Does the heartbleed vulnerability affect clients as severely?
If I have a web crawler (using a non-patched version of OpenSSL) that can be coaxed to connect to an evil https-site, can they get everything from my process memory? To attack a server you can keep ...
- 721
58
votes
4
answers
28k
views
Does Heartbleed mean new certificates for every SSL server?
If you haven't heard of the Heartbleed Bug, it's something to take a look at immediately. It essentially means that an attacker can exploit a vulnerability in many versions of OpenSSL to be able to ...
- 6,765
31
votes
2
answers
30k
views
Extract pre-master keys from an OpenSSL application
Consider an application using OpenSSL which has a bug. A packet capture of the full SSL session is available, as well as a core dump and debugging symbols for the application and libraries. A RSA ...
- 6,028
15
votes
1
answer
9k
views
Is openssl aes-256-cbc encryption safe for offsite backup
I have around 20000 files (around 9GB) each of which is encrypted using openssl enc -aes-256-cbc -in infile -out outfile -k mypassword command. Each file uses same password. My openssl version is 1.1....
- 261
5
votes
1
answer
2k
views
Can OpenSSL decrypt the encrypted signature in an Amazon Alexa request to a web service?
We're using OpenSSL to parse and verify the certificate and signature that Amazon's Alexa sends to external web services, following their list of requirements in the instructions here.
We're ...
12
votes
3
answers
33k
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 ...
- 1,565
37
votes
4
answers
30k
views
Can someone explain what exactly is accomplished by generation of DH parameters?
I'm setting up a node.js server:
https.createServer({
...
ciphers: 'ECDHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4:HIGH:!MD5:!aNULL:!EDH',
honorCipherOrder: true
}, app).listen(443);
...
- 977
21
votes
5
answers
116k
views
How can I verify that SSLv3 protocol is disabled?
I'm trying to disable SSLv3 in ejabberd 2.1.10 on Ubuntu 12.04. There is no way to disable it in config file, so I have to patch the source and rebuild the package: https://github.com/processone/...
- 433
1
vote
1
answer
291
views
What could cause classic "ERR_CERT_DATE_INVALID" when I can confirm no error from numerous other clients?
The ERR_CERT_DATE_INVALID error, I'm sure we're all familiar with, is below
Visiting the same site from numerous other locations, web clients, etc shows a valid certificate.
It's issued by let's ...
- 356
100
votes
2
answers
135k
views
How do I get the RSA bit length with the pubkey and openssl?
I have a public key generated with ssh-keygen and I'm just wondering how I get information on the keylength with openssl?
- 2,599
73
votes
6
answers
234k
views
Converting keys between openssl and openssh
If I use the following
openssl req -x509 -days 365 -newkey rsa:2048 -keyout private.pem -out public.pem -nodes
I get private.pem and public.pem
If I use
ssh-keygen -t rsa -f rsa
I get rsa and ...
- 833
66
votes
3
answers
9k
views
Heartbleed: Why does the client supply the length of the message at all?
"The fix for this bug is simple: check that the length of the message actually matches the length of the incoming request."
Why do we even have the client report the length at all?
If we can know ...
- 743
32
votes
2
answers
19k
views
stronger encryption for SSH keys
I configured my server to encrypt user passwords using 500,000 rounds of SHA-512.
The question is, how does the standard AES-128-CBC encrypted SSH private key stack up to that, provided the same (or ...
- 977
29
votes
5
answers
18k
views
Creating my own CA for an intranet
I need to create my own CA for an intranet and unfortunately it seems there's no good answer about this on Security.SE.
There are many resources online about this, but all of them are different and ...
user42178
26
votes
2
answers
26k
views
What is the difference between Diffie Hellman generator 2 and 5?
Generating Diffie Hellman parameters in OpenSSL can be done as follows:
$ openssl dhparam -out dh2048.pem 2048
Generating DH parameters, 2048 bit long safe prime, generator 2
This is going to take a ...
- 363
21
votes
3
answers
52k
views
OpenSSL generate different types of self signed certificate
Does anyone know how to use OpenSSL to generate certificates for the following public key types:
DSA - For DHE_DSS key exchange.
Diffie-Hellman - For DH_DSS and DH_RSA key exchange.
ECDH - For ...
- 479
21
votes
2
answers
7k
views
Can Heartbleed be used to obtain memory from other processes?
According to http://heartbleed.com/, memory contents can be leaked from the server to the client and vice versa.
Say that I have been banking in a separate browser profile (but under the same user). ...
- 6,028
7
votes
2
answers
25k
views
Subject Alternative Name in Certificate Signing Request apparently does not survive signing
So I have been able to create a Certificate Signing Request with a Subject Alternative Name of the form subjectAltName=IP:1.2.3.4 by following the recipe in a previous (splendid) answer.
When I ...
- 371
162
votes
2
answers
23k
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 ...
- 9,580
49
votes
3
answers
96k
views
Generate CSR from existing certificate
Can we generate the CSR (certificate signing request) used for certificate signing from the signed certificate? It should work with the original private key when signed again with different authority.
- 621
47
votes
4
answers
25k
views
Determine if private key belongs to certificate?
Given a certificate¹ and a private key file², how can I determine if the public key on the certificate matches the private key?
My initial thought was to simply encrypt some text with the public key ...
- 1,056
40
votes
1
answer
10k
views
How does OpenSSL generate a big prime number so fast?
In order to generate a 2048 bit RSA key pair, you need to generate two big prime numbers with 1024 bits length. As far as I know, OpenSSL chooses a random 1024 bit number and starts looking for a ...
- 401
28
votes
6
answers
18k
views
Heartbleed and Routers/ASAs/other
OK, so I first heard about heartbleed a few hours ago through the stack exchange questions feed, and after a moments panic, realised that the only web servers I have secured via OpenSSL are on the ...
- 442
23
votes
2
answers
35k
views
Where is the salt on the OpenSSL AES encryption?
I'm interested in knowing how and where OpenSSL inserts the generated salt on an AES encrypted data. Why? Im encrypting data in Java classes and need to guarantee that I can use OpenSSL to decrypt ...
- 348
16
votes
2
answers
36k
views
How can you check if a private key and certificate match in OpenSSL with ECDSA?
I know how to do this with RSA keys (see this article: Determine if private key belongs to certificate?) however I do not know how to do this for ECDSA certificate / key pairs.
With RSA keys, the ...
- 161
16
votes
4
answers
77k
views
Using the openssl command, how can I tell if it's using TLS 1.0?
Due to a security scan, I was told to not use TLS1.0. I found a link that gave me commands to use to check if a specific protocol is used/enabled. The command I ran (with output is)
(Output from TLS1....
- 263
8
votes
1
answer
7k
views
Do I put my subordinate (intermediate) or root CA certificate in my truststore?
I have a server using a certificate signed by my subordinate (intermediate) CA.
My java based client needs to put either the intermediate or root CA cert in it's truststore so when it communicates ...
- 183
8
votes
3
answers
8k
views
File security when encrypting files directly with the openssl command / and what about SHA1 hashing password first?
I've been using this command to encrypt files for a while now:
openssl aes-256-cbc -a -salt -in secrets.txt -out secrets.txt.enc
Then I type in a password.
Can someone tell me, roughly speaking, ...
- 273
7
votes
2
answers
4k
views
WPA2 Enterprise EAP-TLS Key Exchange
I'm in the process of implementing 802.1x WPA2 Enterprise Authentication using FreeRadius and EAP-TLS (Mutual TLS Cert Based Auth).
I am keen to understand how to actual protocols work together and ...
- 71
7
votes
1
answer
10k
views
How to add AltName from csr file to crt file using "openssl x509 -req"?
I'm a webdeveloper and want to test my websites locally with a self signed SSL certificate.
Everything was working great until a few days ago, when chrome started complaining about a missing AltName ...
- 231
7
votes
2
answers
8k
views
openssl enc uses md5 to hash the password and the salt
Wikipedia states that md5's collision resistance is 2^18 (https://en.wikipedia.org/wiki/MD5).
I just found out that openssl enc uses md5 to hash the password and the salt. Let's assume that I want ...
- 155
6
votes
3
answers
4k
views
Is it possible to modify a CA without having to reissue all of the derived certificates?
Background: I have my own authoritative certificate that I generated myself for signing certificates for services my friends and I use, including web server, ircd, etc. It's convenient because I don'...
- 303
6
votes
2
answers
3k
views
Can a SSL Certificate dictate protocol?
I know you can set the protocol/cipher via your web server:
Nginx:
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers HIGH:!aNULL:!MD5;
Apache:
SSLProtocol all -SSLv2
SSLCipherSuite ...
- 295
4
votes
4
answers
4k
views
Trust a non-root CA in OpenSSL
Is it possible to have OpenSSL trust a non-root CA such that a certificate signed by that non-root CA can be properly verified? I've noticed that the default behavior for OpenSSL is to only verify ...
4
votes
2
answers
6k
views
Can't request ocsp status with chain of certificates
I have deployed basic ocsp server from OpenSSl Cookbook by Ivan Ristic page 44 with following command
$ openssl ocsp -port 9080 -index db/index -rsigner root-ocsp.crt -rkey private/root-ocsp.key -CA ...
- 203
2
votes
1
answer
6k
views
Why is this version of OpenSSL (1.0.1e) not vulnerable to Heartbleed?
I recently ran into a requirement that needed a web server set up with SSL, to show that its possible to extract the private key from a server with a vulnerable version of OpenSSL (Heartbleed). Hence, ...
- 613
1
vote
1
answer
2k
views
decrypt a soap message using openssl
I've tried to do the same as found in How to you manually decrypt a SOAP message using openssl?
Unfortunatly without success...
Here is my situation :
I'm trying to do the same stuff only my data ...
- 13
0
votes
1
answer
737
views
Generate X509 ERR_CERT_COMMON_NAME_INVALID
I am trying to set up https server on python3, but I could not generate a certificate and a key properly.
That is the server code:
import http.server, ssl
server_address = ('localhost', 4443)
httpd =...
0
votes
2
answers
299
views
Different certificates for the same website?
When I load https://objective-see.com in Safari, it shows me a certificate with CN=objective-see.com. However, when I retrieve the certificate using
echo -e | openssl s_client -connect "objective-see....
- 1
0
votes
1
answer
156
views
Can you use Https to prove document was sent from domain?
I'm aware that you can use tools like GPG to both encrypt and sign information.
However HTTPS seems to only be used for encryption. The browser shows me the connection is secure, but there is no way ...
- 537