Openssl Generate Aes 256 Key Base64
OpenSSL is well known for its ability to generate certificates but it can also be used to generate random data. Base64 Generates 32 random bytes (256bits) in a base64 encoded output: openssl rand -base64. $ openssl enc -aes-256-cbc -k secret -P -md sha1 salt=E2EE3D7072F8AAF4 key=C94A324B7221AA8A8760DA0717C80256EF4308EC6068B7144AA3BBA4A5F98007 iv =5C7CB13DBDA69B2C091E0D5E95943627 I thought I could just read the key string and base64 decode it to get a 256-bit AES key, but that didn't work because 64 characters turned into a 384-bit byte array. May 07, 2012 Using AES-256-CBC with OpenSSL, node.js and PHP. GitHub Gist: instantly share code, notes, and snippets. $ openssl enc -aes256 -base64 -in some.secret -out some.secret.enc enter aes-256-cbc encryption password: Verifying - enter aes-256-cbc encryption password: It will encrypt the file some.secret using the AES-cipher in CBC-mode. Steam cd key generator cs go. The result will be Base64 encoded and written to some.secret.enc. OpenSSL will ask for password which is used to. The following command will prompt you for a password, encrypt a file called plaintext.txt and Base64 encode the output. The output will be written to standard out (the console). SHA1 will be used as the key-derivation function. We will use the password 12345 in this example. $ openssl enc -aes-256-cbc -in plaintext.txt -base64 -md sha1.
Ecrypt data using aes-256-cbc without salt
Decrypt the encrypted data by add one more option -d$ echo 'HEQ/s/mOMof648tJxJvvwtHUTcq2j021RbgvqLA02lY=' openssl aes-256-cbc -a -nosalt -d -k hellothis is hello world-d meas decryption
Your can also use openssl encrypt files by passing the -in -out params. without -k option, it will prompt for a password.
Openssl Generate Aes 256 Key Base64 Free
Let's play it one more time, the output is exactly the same as the previous one. This is because we turned off the salt.
Ecrypt data using aes-256-cbc with salt
Let's play it one more time.
Openssl Generate Aes 256 Key Base64 Code
Each time we encrypt with salt will generate different output.
The same as encryption by add -d option.
Add -p option the checkout what did openssl do while encryption:
- It first generate an 8-byte long salt;
- By concating the password and salt, it generate the key(32 byte length) and iv(16 byte length)
- Then encrypt the data with key and iv using standard aes-255-cbc algorigthm;
So what's algorithm used for generating the key and iv?From openssl docs:https://www.openssl.org/docs/manmaster/man3/EVP_BytesToKey.htmlIt simply using md5 of the salt and password.md5 generate 16-byte data one time. but the key(32-byte) and iv(16-byte) totally need 48-byte data.So we need to run md5 at least 48/16 = 3 time.
ps: Why key is 32-byte length and iv for 16-byte length?
- aes-256-cbc, 256 meas it use 256 bit key, that's 32-byte.
- so aes-192-cbc use 24-byte key;
- aes-128-cbc use 16-byte key.
- iv is always 16-byte.
Next question, how do we get the salt from ecrypted data. Let's check it.
or.
The first 8-byte of encrypted data is 'Salted__', which meas the data was encrypted using salt.The next 8-byte is the salt, which is exactly the same as openssl -p output.
Openssl Base64 Example
The left bytes are the cncryped data.