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

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What should end-users do about Heartbleed?

What should one 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 they need to ...
213
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4answers
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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 ...
196
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1answer
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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 ...
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2answers
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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 ...
110
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5answers
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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 ...
222
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11answers
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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?
57
votes
2answers
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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 ...
58
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4answers
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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 ...
11
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2answers
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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 ...
60
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3answers
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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 ...
19
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2answers
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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). ...
23
votes
2answers
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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 ...
25
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2answers
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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?
16
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5answers
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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 ...
27
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6answers
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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 ...
5
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2answers
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Extensions for SSL server certificate

I have some question about the X.509 v3 extensions. What extensions should appear in a proper certificate for a SSL server ?
2
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3answers
810 views

What part of the CSR is hashed in order to create its signature?

I'd like to change the CSR before it is transferred to the CA without going through the CSR creation process again. To do that I need to know how to calculate the signature of the CSR after I modified ...
14
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4answers
51k 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 ...
21
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3answers
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Can someone explain a little better 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); ...
17
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3answers
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How to check if a server is not vulnerable to Logjam?

In response to Logjam I want to prove I've hardened my services. I know that the DH param has to be 2048 bits at least and self generated. But I am unable to find a way to actually check this for ...
7
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2answers
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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 ...
5
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2answers
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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 ...
6
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2answers
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OpenSSL PKCS#7 vs. S/MIME

OpenSSL 1.0.1c onwards seems to offer CMS support. I have difficulty understanding the difference between smime and pkcs7. S/MIME specs are layered on PKCS#7 (so says Wikipedia). Now in openssl I ...
12
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1answer
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What are the OpenSSL standard Diffie Hellmann parameters (primes)?

I recently generated some custom Diffie Hellmann parameters which are basically just long (in the below case 4096 bit) primes. Those are then used in the key exchange process. I used the following ...
7
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1answer
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Does Heartbleed affect servers if OpenSSL was only used to generate the certificate?

I built an application that generates certificate signing requests (CSRs) using the PHP OpenSSL module. Is there a way that the HeartBleed bug can affect these (in use) private keys and CSRs that ...
5
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2answers
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Are there any known Heartbleed attacks?

Are there any known instances of malicious security breeches exploiting the Heartbleed vulnerability? Or is there at present only a known vulnerability, albeit a very serious one?
5
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1answer
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Which extensions to use for a S/MIME certificate?

Analogously to the SSL server certificate question, which extensions should I use for S/MIME, and should the CA be restricted somehow as well? (I'm using openssl, which at the moment creates CA and ...
5
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1answer
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How do I create a valid email certificate for Outlook S/MIME with openssl?

I need to create a certificate for email encryption and signing that has to be used by Outlook 2003+. I'm using OpenSSL, my self-signed root-CA is already imported into the trusted root-CA store. ...
4
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2answers
344 views

Explicitly prohibit an intermediate CA certificate on OpenSSL

How do you explicitly not trust a particular certificate (especially, CA certificate) for OpenSSL? On NSS-based applications, one can install the cert with trustarg p: prohibited (explicitly ...
3
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2answers
102 views

Using Self sign certificate in internet

Basically the purpose of SSL cert is for trusting each other. If I have an application that only a few clients I know can use, is generating self sign certs enough? Or do I really need to sign with a ...
1
vote
1answer
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OpenSSL: Enable cipher suites per protocol version

Is there a way to explicitly configure OpenSSL to allow AES (or in general, block ciphers) only for clients that use a TLS version >= 1.1? This would protect against the BEAST attack, while still ...
0
votes
1answer
62 views

Why does not appear the public key from certificate?

I'm creating a certificate in LAMP, the public key is: Public Key: 30 81 89 02 81 81 00 CC CB 64 54 C2 FA A3 7A 81 36 5F 1B D5 10 81 75 B7 42 02 31 83 B1 D5 5A 76 72 6A 77 BE 62 69 16 AB EB 39 66 B5 ...
9
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5answers
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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: ...
25
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1answer
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Can a CSR be created in OpenSSL with SHA2?

Can a CSR be created in OpenSSL with SHA2? If so, what would the command be and what does this tell the CA, if anything? If you could create a CSR using SHA2 would it "tell" the signing CA to use it ...
15
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4answers
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Why OpenSSL can't use /dev/random directly?

I couldn't find the answer for the reason anywhere, even the wiki page doesn't explain it. This seems like using a PRNG for seeding an another PRNG. The first one (/dev/random) may itself be seeded by ...
9
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1answer
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Heartbleed how to find out applications using statically compiled version of openssl?

We're analysing issue at work and I wondering how to find out if there's any binary with a statically compiled version of openssl which includes this bug. Would it be possible to find a fingerprint ...
5
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2answers
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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 ...
4
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3answers
4k views

Could I delete .csr files when the key is signed by CA

I'm creating my own openvpn server. The Certificate authority is located on a separated host. There is two kind of clients: which that just send a .csr and to which i send the .crt as an answer and ...
10
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2answers
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OpenVPN dhparam

One of the steps for setting up OpenVPN is running the command openssl dhparam -out dh1024.pem 1024. The man page tells me this 1024 value refers to the number of bits. Why is the value 1024 ...
7
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1answer
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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 ...
5
votes
3answers
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P12 - Extract public part (certificate) without knowing the p12 password

I would like to extract the public part of a revoked P12 which doesn't belong to me. I can't open it with KeyStore Explorer because I am prompted for the password, is it possible with OpenSSL ? The ...
3
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1answer
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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 ...
2
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2answers
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OpenSSL, x509: what's the significance of CN (Common Name)?

With regard to these three items Certificate Authorities (CA) Gateway certificates End-point Certificates (client-cert) What is the significance of the Common Name CN with regard to the a VPN? ...
2
votes
1answer
1k views

What is the difference between `extendedKeyUsage` and an application policy?

In some Microsoft articles like http://technet.microsoft.com/en-us/library/cc731792%28v=ws.10%29.aspx, I find some confusing statements like Application policies are sometimes called extended key ...
10
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1answer
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How to get a 'million rounds of PKCS#8 + PBKDF2' with OpenSSL?

I posted this question Is a passphrase-protected SSH private key susceptible to a dictionary attack? a few days back. An excerpt from the final answer: With PKCS#8 + PBKDF2 and one million ...
6
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3answers
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Why does OpenSSL need the private key to revoke a certificate?

openssl ca -revoke signed/0A.pem -config caconfig.cnf What does this do which requires the CA's private key? Does it do anything except updating index.txt?
5
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2answers
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FIPS Compliance for my Android project

I am working on a security-related project and have to make sure it is FIPS 140-2 compliant. According to my understanding, FIPS compliance is compliance at hardware as well as software level. ...
4
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2answers
329 views

Heartbleed and heap management - Why user data and passwords are kept in memory?

If I understand correctly the hearbleed vulnerability, only the heap of the OpenSSL process can be retrieved by an attacker (or part of depending on the memory allocation type that is used). Then, how ...
3
votes
1answer
130 views

How to trust a CA to sign a CRL but not a cert?

In my application, there are many parties that are trusted to revoke a cert (ie by signing a CRL), but are not trusted to sign (new) certs. How do I mark a CA to be trusted only for CRLs, and not for ...
3
votes
2answers
538 views

Why is a CSR hashed?

What are the use cases for defining something other than the default SHA1 hash in a CSR? Is it to protect the digital signature, public/private keys? What is it protecting exactly?