OpenSSL: Symmetric Encryption Algorithms & Examples

Posted on Feb 8, 2025 in Computing and Communications

Symmetric Encryption Algorithms with OpenSSL

Encrypt the file “fichero.txt” using the RC4 symmetric encryption algorithm

OpenSSL> rc4 -in c:\cifrado\fichero.txt -out c:\cifrado\cifrado.rc4

enter rc4 encryption password:
Verifying - enter rc4 encryption password:

Decrypt the previous file:

OpenSSL> rc4 -d -in c:\cifrado\cifrado.rc4 -out c:\cifrado\descifrado.txt

enter rc4 decrypt password:

DES

Encrypt:

OpenSSL> des -salt -in c:\csb.log -out c:\csb.bf.txt

enter des-cbc encryption password:

Verifying - enter des-cbc encryption password:

Decrypt:

OpenSSL> des -d -in c:\csb.bf.txt -out c:\csb.txt

enter des-cbc decryption password:

Triple DES (DES3)

OpenSSL>enc -des3 -salt -in c:\cifrado\fichero.txt -out c:\cifrado\ficherocif.bin
enter des-ede3-cbc encryption password:
Verifying - enter des-ede3-cbc encryption password:

OpenSSL>enc -des-ede3-cbc -salt -in c:\cifrado\fichero.txt -out c:\cifrado\ficherocif.bin
enter des-ede3-cbc encryption password:
Verifying - enter des-ede3-cbc encryption password:

OpenSSL>enc -des3 -d -in c:\cifrado\ficherocif.bin -out c:\cifrado\original.txt
enter des-ede3-cbc encryption password:

OpenSSL> enc -des-ede3-cbc -d -in c:\cifrado\ficherocif.bin -out c:\cifrado\original.txt

enter des-ede3-cbc decryption password:

IDEA – International Data Encryption Algorithm

Operates on 64-bit plaintext blocks with a 128-bit key (no parity). It is twice as fast as DES, despite using much longer keys.

OpenSSL> idea-ecb -salt -in c:\csb.log -out c:\csb.idea-ecb.txt

enter idea-ecb encryption password:

Verifying - enter idea-ecb encryption password:

OpenSSL> idea-cbc -salt -in c:\csb.log -out c:\csb.idea-cbc.txt

enter idea-cbc encryption password:

Verifying - enter idea-cbc encryption password:

OpenSSL> idea-ecb -d -in c:\csb.idea-ecb.txt -out c:\csb.idea-ecb.d.txt

enter idea-ecb decryption password:

OpenSSL> idea-cbc -d -in c:\csb.idea-cbc.txt -out c:\csb.idea-cbc.d.txt

enter idea-cbc decryption password:

AES

OpenSSL>aes-128-cbc -salt -in c:\cifrado\fichero.txt -out c:\cifrado\fichero.txt.aes

Decrypt the previous file to obtain the plaintext message.

OpenSSL>aes-128-cbc -d -salt -in c:\cifrado\fichero.txt.aes -out c:\cifrado\fichero.txt

The most secure and fastest:

Encrypt the file “fichero.txt”

OpenSSL>aes-256-cbc -salt -in c:\cifrado\fichero.txt -out c:\cifrado\fichero.txt.aes

Decrypt the previous file to obtain the plaintext message.

OpenSSL>aes-256-cbc -d -salt -in c:\cifrado\fichero.txt.aes -out c:\cifrado\fichero.txt

OpenSSL>cast -in c:\cifrado\fichero.txt -out c:\cifrado\fichrc5.bin
enter cast5-cbc encryption password:
Verifying - enter cast5-cbc encryption password:

OpenSSL>cast -d -in fichrc5.bin
enter cast5-cbc decryption password:

OpenSSL> cast5-ecb -salt -in c:\csb.log -out c:\csb. cast5-ecb.txt

enter cast5-ecb encryption password:

Verifying - enter cast5-ecb encryption password:

OpenSSL> cast5-ecb -d -in c:\csb.cast5-ecb.txt -out c:\csb.cast5-ecb.d.txt

enter cast5-ecb decryption password:

OpenSSL> bf -salt -in c:\csb.log -out c:\csb.bf.txt

enter bf-cbc encryption password:

Verifying - enter bf-cbc encryption password:

OpenSSL> bf -d -in c:\csb.bf.txt -out c:\csb.txt

enter bf-cbc decryption password:

OpenSSL>base64 -in c:\cifrado\ficherocif.bin -out c:\cifrado\base64.txt

OpenSSL>base64 -d -in c:\cifrado\base64.txt -out c:\cifrado\ficherocif2.bin

Encrypt a file using the blowfish algorithm and encode it in base64 in one step.

OpenSSL>enc -e -a -salt -bf -in c:\cifrado\tomcat.jpg -out c:\cifrado\tomcat.blowfish
enter bf-cbc encryption password:
Verifying password - enter bf-cbc encryption password:

Decrypt the previous file

OpenSSL>enc -d -a -bf -in c:\cifrado\tomcat.blowfish -out c:\cifrado\tomcat-decrypt.jpg
enter bf-cbc decryption password:

OpenSSL> md5 c:\text.txt

MD5(c:\text.txt)= 1798c318d32f787b1befd7812c94ff4b