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

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3
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1answer
380 views

How can I use my HSM to turn a CSR into a certificate?

I create a CSR using OpenSSL, so I have public and private keys. Now I want to sign this CSR and convert it into an X.509 certificate. The only problem is, my signer is a custom HSM. I can send bytes ...
4
votes
2answers
254 views

Why is openssl key length different from specified bytes

I realize this is rudimentary question, but I can't seem to even google diagnose it. Why is openssl key length different from specified bytes? For example when I use the command: openssl genrsa -out ...
0
votes
1answer
144 views

How are man-in-the-middle attacks actually implemented? [closed]

For research purposes. I'm wondering, in a high level way, how MITM attacks are actually done in the real world. So over the internet the client talks to the server, or one person emails the other, ...
1
vote
1answer
113 views

What does it mean to “sign with a certificate”? [duplicate]

As part of the SSL handshake, the server responds to the browser with 2 things - The server's public key Some metadata, like what version of SSL is being used, the cipher algorithm being used, etc......
4
votes
1answer
296 views

OpenSSL 0.9.6a PRNG algorithm weakness: How to exploit?

I saw an OpenSSL security advisory for Openssl 0.9.6a Recently a cryptographic flaw in OpenSSL's built-in pseudo-random number generator (PRNG) was pointed out to us by Markku-Juhani O. Saarinen , ...
5
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2answers
11k views

SSL3 error when requesting connection using TLS 1.2

I've come across several hosts that throw SSL3 handshake errors even though I explicitly request TLS 1.2. Why is this? Am I using the openssl client wrong? $ openssl s_client -tls1_2 -connect i-d-...
4
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2answers
1k views

Determine if a server is asking for a client certificate using openssl s_client

I am using openssl to connect to servers to detect if they require a client certificate. Currently I am using this command: openssl s_client -connect pokyloky.com:5222 -state 2>&1 | grep '...
1
vote
1answer
636 views

SNI (server name indication) with SSL

Is it possible to use SNI (server name indication) in SSLv3 or SSLv2 handshake? From the search queries, it seems SNI is TLS extension. Is there any alternate to SNI?
2
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1answer
340 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, ...
1
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2answers
1k views

Can I rely on openssl_random_pseudo_bytes() being very random in PHP?

I came across an application which needs to generate a random token for each user. It is very important that each generated token is unique. Application code was as follows: $token = md5(...
1
vote
1answer
93 views

What guarantees does perfect forward secrecy make with respect to compromise of a private key?

With perfect forward secrecy, if an attacker gains access to a certificate private key, my understanding is that all traffic previously encrypted using that private key remains safe from decryption. ...
2
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2answers
2k views

Is it possible to salt the SHA1 or SHA256 hash function of OpenSSL?

I would like to salt the hash function of OpenSSL external, so that I can assign a salt on my own. Is that possible or is the hash function of OpenSSL alsways internal "salted"?
5
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2answers
2k views

Private key to PEM

I'm new to security and I'm trying to decode some SSL encrypted communication between my machine and server. I managed to obtain private and public keys as far as I understand private key is this one:...
2
votes
1answer
741 views

Difference between certificates with “extension fields” and “Non Repudiation” usage

For example we have two certificate pairs: First pair: Server cert with "Non Repudiation" (sometimes called Content Commitment) usage, Client cert without any "extension fields". Second pair: ...
-4
votes
2answers
81 views

Does SSL doesn't work without a secondary Symmetric/Asymmetric session key?

I keep reading that Symmetric session key is used in SSL after handshake only for faster performance but isn't true a secondary session key either Symmetric or Asymmetric key generated by the client ...
1
vote
1answer
412 views

Cannot connect using ECDH-RSA-AES256-SHA

I try to establish an SSL connection using the ECDH-RSA-AES256-SHA cipher using OpenSSL, but it fails saying "no shared cipher": On the server, I run: $ openssl s_server -cert selfsigned_cert.pem -...
3
votes
1answer
131 views

Sign certificates using a web server certificate issued by a public CA

I have obtained a certificate from GoDaddy. It's usage and constraints are as follows: Key Usage Digital Signature, Key Encipherment (a0) Enhanced Key Usage: Server Authentication (1.3.6.1.5.5.7....
18
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3answers
2k views

Will my hosting provider be able to see my SSL private keys?

I'm trying to learn the best way to implement a secure web and e-mail server. Getting SSL certificates is a must, but what happens with the private keys? I've seen that you have to store them on the ...
2
votes
1answer
371 views

Can SHA256 signature support be deduced from TLS cipher suites or any other part of ClientHello (if no signature_algorithm sent)?

Websites aiming to maintain maximum compatibility with (legacy) browsers may wish to serve SHA2-signed certificate chains to those user agents that support them, and SHA1 to those that don't. The TLS ...
2
votes
2answers
522 views

Best way to scan for and eliminate earlier versions of SSL/TLS in a production environment

Due to new PCI DSS standards mandating that nothing lower than TLS 1.2 be used in a PCI environment, I am tasked with phasing out anything lower than TLS 1.2 on every device in this environment by our ...
4
votes
3answers
4k views

Difference between OpenSSL and keytool

I was wondering about differences between using OpenSSl or Keytool and generating certificates by them. I think Keytool is used by Java community but for someone who is not remotely connected to Java ...
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0answers
1k views

verifying digest signed with private key using a C program

I'll explain all the steps I've done so far and conclude with my question. using OpenSSL 1.0.1e-fips 11 Feb 2013 Generating a private and public key openssl genrsa -des3 -out private.pem 2048 ...
7
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2answers
1k views

Are all SSL/TLS implementations vulnerable to the Heartbleed bug? [closed]

I've learned the theory behind the SSL/TLS protocols and how effective they are to achieve a secure communication between clients and servers. Do all the implementations OpenSSL, PolarSSL, MatrixSSL, ...
1
vote
6answers
366 views

Can people know the server I'm connecting to despite being on SSH/HTTPS? [duplicate]

I understand that by connecting securely over SSH or HTTPS, the data that I transfer is cryptographically secure. However, can someone spying on my connection still determine the server I'm sending it ...
0
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1answer
35 views

importing CA certs into OpenSSL CLI

I created a CA cert and a cert signed by the CA cert and then tried to sign a CMS / PKCS7 message with the CA-signed cert and got the following error: unable to get local issuer certificate I.e. it ...
0
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1answer
189 views

how to validate PKCS7 signed message signed with a self-signed cert via OpenSSL CLI

openssl cms -in demo.p7m -inform DER -verify verifies the signature on a CMS / PKCS7 encoded message but if the cert that did the signing is self-signed I get a "self signed certificate" error. ie. it ...
3
votes
1answer
150 views

How can Heartbleed checkers determine if a site is vulnerable?

As far as I know, there is not a way to obtain OpenSSL's version from a website. Then what kind of information does a Heartbleed checker obtain so it can determine if a site is safe from Heartbleed or ...
5
votes
0answers
179 views

Secure backup encryption with OpenSSL

I know, the general advice is "keep your hands off crypto stuff". And the standard way to encrypt backup data securely would be using GnuPG. However, for a rather academic exercise, I would like to ...
1
vote
3answers
362 views

Security RESTful web application in Java

We are developing two web applications: Application A : Restful web-services running on a GlassFish Server . Application B : Dynamic web application running on a Tomcat Server . I am accessing ...
3
votes
1answer
417 views

How to generate keystore for root signed certificate?

I need to create keystore and truststore with root signed certificates. I have these files (at this step they are identical for client and for server): client_cert.pem client_prv_key.pem root_cert....
5
votes
1answer
122 views

OpenSSL Certificate Expiry

I'm trying to use OpenSSL to verify that an SSL certificate is still valid, but I keep getting strange results. The example site that I'm testing with (expired.badssl.com) has an expired SSL ...
1
vote
1answer
323 views

Using cipher suite: deployment commands

Can someone point me in using the correct OpenSSL commands to use a certain cipher suite. For example DHE-RSA-AES256-GCM-SHA384 (I am not using ECDH suite because of supposed NSA backdoor controversy/...
5
votes
1answer
198 views

Is there an official standard and/or name for PEM certificate bundles?

This is a question that's not really about security proper. It's about security/crypto nomenclature. It's been bugging me a bit, so here goes: I know two approaches for bundling related certificates/...
2
votes
2answers
469 views

Why does StartTLS block connection to apache

When I run this command: openssl s_client -connect my.server:443 -starttls smtp Why does Apache 2.4 & OpenSSL 1.0.1h(running on server 2008R2) stop responding to request from other machines ? ...
2
votes
1answer
331 views

For maximum security is it best to link OpenSSL libraries statically or dynamically?

When linking to OpenSSL (or other cryptographic libraries) would it be more secure to use a shared library and have address space layout randomization, or to use a static library and not have ASLR?
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0answers
72 views

How to inform other sysadmins their email encryption is broken [closed]

Does anyone have a good template email to use to send to remote system/mail/security administrators to alert them to the fact that emails to them would not be getting through either at all or securely ...
-2
votes
1answer
48 views

A collection of tests and demos for security headers and TLS configurations [closed]

There are (or have been) various websites designed to educate and provide examples on good / bad configurations of security headers and TLS configurations (e.g. https://badssl.com/) I want to build a ...
3
votes
2answers
102 views

Concepts of a secure note sharing system

I am trying to design a system that will allow for staff members in our small company to securely share sensitive customer information (text) and see them on a web page alongside less sensitive ...
2
votes
2answers
555 views

OpenSSL x509: Is there an order in subjectName fields?

Is there an order to respect in subjectName field when creating a x509 certificate with OpenSSL command? In other words, what are all possibilities of displaying subjectName of x509 certificate in ...
1
vote
1answer
431 views

Create Public Key using OpenSSL instead of PuTTYgen for PKCS#8

I'm trying to create a public key pair for ssh-rsa authentication. If I'm using puttygen.exe, the "OpenSSH authorized_keys file" string looks like this: "ssh-rsa AAAAB3 ... 6yIK9Nbw== rsa-key-...
7
votes
1answer
565 views

How does the OpenSSL Alternative chains certificate forgery (CVE-2015-1793) attack work?

The security advisory for the issue can be found here: https://www.openssl.org/news/secadv_20150709.txt OpenSSL Security Advisory [9 Jul 2015] Alternative chains certificate forgery (CVE-2015-...
4
votes
1answer
280 views

What encryption is applied on a key generated by `openssl req`?

When a key is generated with openssl genrsa, the encryption is selected with a command line argument such as -aes128. After the key is generated, we can see what encryption was used in the file. Ex: ...
2
votes
1answer
194 views

OpenSSL implementation vulnerabilities vs TLS 1.0 holes

I have been reading a fair bit on OpenSSL vulnerabilities and the various SSL protocols' strengths. As far as I understand it any protocols older than TLS 1.0 are to be avoided at all cost (some would ...
3
votes
1answer
5k views

Chrome showing SSL warning about SHA-1 when the sites don't use SHA-1

My version of Chrome on an iMac (latest 43.0.2357.130 (64-bit)) is showing an SSL warning for well-known sites (Hackernews, GitHub, DigitalOcean): This site uses a weak security configuration (SHA-...
5
votes
1answer
3k views

In SSL server handshake, does server also send CA certificate [duplicate]

In the TCP SSL sever handshake, does the server also send CA certificates? Does the server need to send all intermediate CA certificates in the Server Hello?
3
votes
3answers
4k views

How to pass cipher list to OpenSSL s_client

How we can pass a cipher list to the OpenSSL s_client program? We can pass single cipher by this: openssl s_client -cipher 'ECDHE-RSA-AES256-SHA' -connect www.google.com:443 But how to pass a list ...
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vote
2answers
164 views

Can Client Certificates be tied to a Specific Server Certificate?

I have a Root Certificate Authority and and Intermediate Certificate Authority. I have created a certificate for the server. SSL on Apache is working fine. Browser recognizes my Chain of Trust with ...
2
votes
1answer
390 views

EC private key, RSA certificate. Is this realisable?

I was wondering if is it possible to generate EC private key: openssl ecparam -name sect571r1 -out ecparam.pem openssl ecparam -in ecparam.pem -genkey -noout -out eckey.pem then generate ...
2
votes
2answers
2k views

Why is there a “des-ede3-cbc” in my rsa private key?

I have created an OpenSSL RSA private key and certificate request with 4096 bit with the following command: openssl req -newkey 4096 When I view the private key with openssl asn1parse -in privkey ...
1
vote
1answer
827 views

Create PKCS7 signature, signed by X.509 CA, which embeds an XML file

I have to create a PKCS7 signature file signed by an X.509 certificate and I have to embed an XML file within. How to do that with OpenSSL or any other tool?