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

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Why does OpenSSL append extra bytes when encrypting with aes-128-ecb?

Plaintext: Attack at dawn!! Hex: 41747461636b206174206461776e2121 Key: ...
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1answer
925 views

Good entropy source for generating openssl keys

I need to generate a CA (4096-bit RSA) and server keys for openvpn and I want them to be "top quality". Here is my plan: gather entropy from multiple sources (saving individual files): FreeBSD ...
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2answers
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With OpenSSL and ECDHE, how to show the actual curve being used?

Using openssl s_client -host myserver.net -port 443 I can see the cipher negotiated is indeed using ECDHE for session key ...
6
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2answers
356 views

Is encrypting credit card numbers one by one with rsautl secure?

I wish to encrypt credit card numbers one by one using asymmetric encryption on the command line. My current approach is this… Encrypt: ...
4
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2answers
354 views

Which crypto libraries/programs do we have the most confidence in? [closed]

I have recently begun studying crypto. If it's one thing I have learned it's that we should not implement our own crypto. Therefore we should look to using existing software and libraries. When I ...
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1answer
1k views

OpenSSL padding

I would like to know how much padding OpenSSL algorithms expect.
2
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1answer
260 views

random number generator and seed

I'm working with openssl cryptographic libraries, I'm new to all these cryptographic stuffs and slowly I'm learning all these. I have a doubt regarding random number generator, I'm using ...
1
vote
1answer
338 views

Dual_EC_DRBG and OpenSSL on a Mac

Since there is not much info anywhere on the Internet related to this: Does anyone know if OpenSSL's default CSPRNG is Dual_EC_DRBG or not? Their wiki is not very clear… Related to the first ...
1
vote
1answer
523 views

RSA Decryption with Private Key but no public exponent

I manually set the RSA private key, given the private exponent and modulus. When I use this key to decrypt a message encrypted using a public key (also set with public exponent and modulus) seems to ...
12
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1answer
4k views

What to watch for with openssl generating weak keys? (low entropy)

(Disclaimer: I am regular software engineer with only basic crypto knowledge, so helpful if can be explained for a layman.) I am concerned about generating weak keys on a shared linux box with ...
2
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1answer
360 views

Why does openssl BN_generate_prime return only a fraction of the safe primes within the given bit range?

I went into prime generation issues the last week and eventually calculated 10^7 primes using erik tews safeprimegen python wrapper for openssl. (https://github.com/eriktews/gensafeprime) (System: ...
2
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1answer
523 views

What key exchange do OpenSSL and CryptoAPI prefer by default?

Here is what I know. When I connect to a brand-new Linux Web server with Chrome and click the "lock" icon, the key exchange algorithm is described as "ECDHE_RSA". (Yes I know what that is.) When I ...
1
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1answer
567 views

How to supply the GCM authentication tag to the OpenSSL command line tools?

I'm using AES-256-GCM for authenticated encryption. In order to decrypt, the ruby OpenSSL library requires an auth_tag parameter (in addition to the key and iv). ...
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1answer
671 views

Sending TLS messages with out encryption using openssl code

Is it possible to send messages over TLS with out encryption? If so which cipher suite is needed for this?
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1answer
250 views

is this authenticated key exchange protocol sound? too complicated? obviously flawed?

(significantly reworded this question to fit better into crypto.se). I have static RSA keypairs for both sides and an encrypted transport that needs symmetric keys, and need to exchange session keys. ...
1
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0answers
115 views

openssl logs showing keyblock length of only 88 bytes instead of 136 bytes

I was decrypting TLS encrypted data from wireshark using the openssl(TLS1.0 version) TLS logs which provides the complete key block which of size 136 bytes.Now i moved to TLS(1.2 version) in that Key ...
2
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3answers
4k views

OpenSSL AES 256-bit Key Management

I am using C and OpenSSL to encrypt files. After experimenting with the OpenSSL command line utility, it makes you enter a passphrase that can be any length, but uses that to create a 256-bit key. ...
2
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2answers
6k views

Decrypt digital signature using RSA public key with openssl

I have a digital signature that was created using the following algorithm: a SHA-256 hash of the body of the message is calculated. It is then signed using an RSA private key and the result is ...