C Openssl Generate Aes 256 Key

BASICS

#include openssl/evp.h #define AES256KEYLENGTH 32: #define AES256KEYLENGTHBITS 256: #define AES256IVECLENGTH 12: #define AES256GCMTAGLENGTH 16 // encrypt plaintext. // key, ivec and tag buffers are required, aad is optional // depending on your use, you may want to convert key, ivec, and tag to NSData/NSMutableData.

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1. In this little article you will learn a tip to generate your Laravel APPKEY environment variable using openssl. Tagged with laravel, openssl.
2. Encrypt public-private key pair using AES-256 algorithm openssl rsa -in pubpriv.key -out encrypted.key -aes256 Remove keys file encryption and save them to another file.

openssl version -aHow fast it runs on the system using four CPU cores and testing RSA algorithm
openssl speed -multi 4 rsaGet basic help
openssl helpGenerate 20 random bytes and show them on screen
openssl rand -hex 20

ENCODING / DECODING

Encoding a file using Base64
openssl base64 -in file.d­ataEncoding some text using Base64
echo -n 'some text' | openssl base64Base64 decode a file with output to another file
openssl base64 -d -in encode­d.data -out decode­d.d­ata

WORKING WITH HASHES

List digest algorithms available
openssl list -diges­t-a­lgo­rit­hmsHash a file using SHA256
openssl dgst -sha256 file.d­ataHash a file using SHA256 with its output in binary form (no output hex encoding)
No ASCII or encoded characters will be printed out to the console, just pure bytes. You can append ' | xxd'
openssl dgst -binary -sha256 file.dataHash text using SHA3-512
echo -n 'some text' | openssl dgst -sha3-­512Create HMAC - SHA384 of a file using a specific key in bytes
openssl dgst -SHA384 -mac HMAC -macopt hexkey:369bd7d655 file.dataCreate HMAC - SHA512 of some text
echo -n 'some text' | openssl dgst -mac HMAC -macopt hexkey­:36­9bd­7d655 -sha512

ASYMMETRIC ENCRYPTION

List elliptic curves available
openssl ecparam -list_­cur­vesCreate 4096 bits RSA public­-pr­ivate key pair
openssl genrsa -out pub_pr­iv.key 4096Display detailed private key information
openssl rsa -text -in pub_priv.key -nooutEncrypt public-private key pair using AES-256 algorithm
openssl rsa -in pub_priv.key -out encrypted.key -aes256Remove keys file encryption and save them to another file
openssl rsa -in encrypted.key -out cleartext.keyCopy the public key of the public-private key pair file to another file
openssl rsa -in pub_priv.key -pubout -out pubkey.keyEncrypt a file using RSA public key
openssl rsautl -encrypt -inkey pubkey.key -pubin -in cleartext.file -out ciphertext.fileDecrypt a file using RSA private key
openssl rsautl -decrypt -inkey pub_priv.key -in ciphertext.file -out decrypted.fileCreate private key using the P-224 elliptic curve
openssl ecparam -name secp224k1 -genkey -out ecpriv.keyEncrypt private key using 3DES algorithm
openssl ec -in ecP384priv.key -des3 -out ecP384priv_enc.key

SYMMETRIC ENCRYPTION

List all supported symmetric encryption ciphers
openssl enc -listEncrypt a file using an ASCII encoded password provided and AES-128-ECB algorithm
openssl enc -aes-128-ecb -in cleartext.file -out ciphertext.file -pass pass:thisisthepasswordDecrypt a file using AES-256-CBC and a keyfile
openssl enc -d -aes-256-cbc -in ciphertext.file -out cleartext.file -pass file:./key.fileEncrypt a file using a specific encryption key (K) provided as hex digits
openssl enc -aes-128-ecb -in cleartext.file -out ciphertext.file -K 1881807b2d1b3d22f14e9ec52563d981 -nosaltEncrypt a file using ARIA 256 in CBC block cipher mode using a specified encryption key (K:256 bits) and initialization vector (iv:128 bits)
openssl enc -aria-256-cbc -in cleartext.file -out ciphertext.file -K f92d2e986b7a2a01683b4c40d0cbcf6feaa669ef2bb5ec3a25ce85d9548291c1 -iv 470bc29762496046882b61ecee68e07c -nosaltEncrypt a file using Camellia 192 algorithm in COUNTER block cipher mode with key and iv provided
openssl enc -camellia-192-ctr -in cleartext.file -out ciphertext.file -K 6c7a1b3487d28d3bf444186d7c529b48d67dd6206c7a1b34 -iv 470bc29762496046882b61ecee68e07c

DIGITAL SIGNATURES

Generate DSA parameters for the private key. 2048 bits length
openssl dsaparam -out dsaparam.pem 2048Generate DSA public-private key for signing documents and protect it using AES128 algorithm
openssl gendsa -out dsaprivatekey.pem -aes-128-cbc dsaparam.pemCopy the public key of the DSA public-private key file to another file
openssl dsa -in dsaprivatekey.pem -pubout -out dsapublickey.pemTo print out the contents of a DSA key pair file
openssl dsa -in dsaprivatekey.pem -text -nooutSigning the sha-256 hash of a file using RSA private key
openssl dgst -sha256 -sign rsakey.key -out signature.data document.pdfVerify a SHA-256 file signature using a public key
openssl dgst -sha256 -verify publickey.pem -signature signature.data original.fileSigning the sha3-512 hash of a file using DSA private key
openssl pkeyutl -sign -pkeyopt digest:sha3-512 -in document.docx -inkey dsaprivatekey.pem -out signature.dataVerify DSA signature
openssl pkeyutl -verify -sigfile dsasignature.data -inkey dsakey.pem -in document.docxCreate a private key using P-384 Elliptic Curve
openssl ecparam -name secp384r1 -genkey -out ecP384priv.keyEncrypt private key using 3DES algorithm
openssl ec -in ecP384priv.key -des3 -out ecP384priv_enc.keySign a PDF file using Elliptic Curves with the generated key
openssl pkeyutl -sign -inkey ecP384priv_enc.key -pkeyopt digest:sha3-512 -in document.pdf -out signature.dataVerify the file's signature. If it's ok you must receive 'Signature Verified Successfully'
openssl pkeyutl -verify -in document.pdf -sigfile signature.data -inkey ecP384priv_enc.key

DIGITAL CERTIF­ICATES

Generating a CSR file and a 4096 bits RSA key pair
openssl req -newkey rsa:4096 -keyout private.key -out request.csrDisplay Certificate Signing Request ( CSR ) content
openssl req -text -noout -in request.csrDisplay the public key contained in the CSR file
openssl req -pubkey -noout -in request.csrCreating a Certificate Signing Request ( CSR ) using an existing private key. This can be useful when you need to renew the public digital certificate without changing the private key.
openssl req -new -key private.key -out request.csrCreate EC P384 curve parameters file to generate a CSR using Elliptic Curves in the next step.
openssl genpkey -genparam -algorithm EC -out EC_params.pem -pkeyopt ec_paramgen_curve:secp384r1 -pkeyopt ec_param_enc:named_curveCreate a CSR file using Elliptic Curve P384 parameters file created in the previous step. Instead of using RSA keys.
openssl req -newkey ec:EC_params.pem -keyout EC_P384_priv.key -out EC_request.csrCreate a self-signed certificate, a new 2048 bits RSA key pair with one year of validity
openssl req -newkey rsa:2048 -nodes -keyout priv.key -x509 -days 365 -out cert.crtCreate and sign a new certificate using the CSR file and the private key for signing ( you must have a openssl.cnf file prepared )
openssl ca -in request.csr -out certificate.crt -config ./CA/config/openssl.cnfDisplay PEM format certif­icate information
openssl x509 -text -noout -in cert.crtDisplay certificate information in Abstract Sintax Notation One (ASN.1)
openssl asn1parse -in cert.crtExtract the certif­icate's public key
openssl x509 -pubkey -noout -in cert.crtExtract the public key's modulus in the certificate
openssl x509 -modulus -noout -in cert.crtExtract the domain certificate from an HTTPS/TLS connection
openssl s_client -connect domain.com:443 | openssl x509 -out certificate.crtConvert a certificate from PEM to DER format
openssl x509 -inform PEM -outform DER -in cert.crt -out cert.derChecking whether the certificate pubic key matches a private key and request file. One step per file. Must match in the output hashes.
openssl x509 -modulus -in certificate.crt -noout | openssl dgst -sha256
openssl rsa -modulus -in private.key -noout | openssl dgst -sha256
openssl req -modulus -in request.csr -noout | openssl dgst -sha256

WORKING WITH TLS PROTOCOL

List all cipher suites supported
openssl ciphers -V 'ALL'List all cipher suites supported with AES
openssl ciphers -V 'AES'List all cipher suites supporting CAMELLIA & SHA256 algorithms.
openssl ciphers -V 'CAMELLIA+SHA256'TLS connection to a server using port 443 (HTTPS)
openssl s_client -connect domain.com:443

C Openssl Generate Aes 256 Key Size

TLS connection to a server using v1.2
openssl s_client -tls1_2 -connect domain.com:443TLS connection & disable v1.0
openssl s_client -no_tls1 domain.com:443TLS connection using a specific cipher suite
openssl s_client -cipher DHE-RSA-AES256-GCM-SHA384 domain.com:443TLS connection displaying all certificates provided by server
openssl s_client -showcerts domain.com:443Setting up a listening port to receive TLS connections using a certificate, the private key & supporting only TLS 1.2
openssl s_server -port 443 -cert cert.crt -key priv.key -tls1_2Extract the domain certificate from an HTTPS/TLS connection
openssl s_client -connect domain.com:443 | openssl x509 -out certificate.crtnmap command: Display enabled cipher-suites over an HTTPS/TLS Connection
nmap --script ssl-enum-ciphers -p 443 domain.comnmap command: Display enabled cipher-suites over a TLS (HTTPS) Connection using SNI. (change it to desired IP & domain name)
nmap --script ssl-enum-ciphers --script-args=tls.servername=domain.com 172.67.129.11

PERSONAL SECURITY ENVIRO­NMENTS ( PSE )

Convert a certif­icate from PEM (base64) to DER (binary) format
openssl x509 -in certif­ica­te.pem -outform DER -out certif­ica­te.d­erInsert certificate & private key into PKCS #12 format file. These files can be imported in windows certificate manager or to a Java Key Store (jks) file
openssl pkcs12 -export -out cert_key.p12 -inkey private.key -in certificate.crtTo show the contents of a PKCS #12 file
openssl pkcs12 -in cert_k­ey.p­12Convert the .p12 file into a Java Key Store. This commnad uses java keytool instead of openssl.
keytool -importkeystore -destkeystore javakeystore.jks -srckeystore cert_key.p12 -srcstoretype pkcs12Convert PEM certificate to PKCS #7 format
openssl crl2pkcs7 -nocrl -certfile certificate.crt -out cert.p7bConvert a PKCS #7 file from PEM to DER
openssl pkcs7 -in cert.p7b -outform DER -out p7.der

SIMPLE CA CONFIG­URATION FILE ( openss­l.cnf )

[ ca ]
default_ca = CA_default
[ CA_default ]
dir = ./pers­onalCA
database = $dir/i­nde­x.txt
new_ce­rts_dir = $dir/newcerts

Aes 256 Software

certif­icate = $dir/c­ace­rt.pem
serial = $dir/s­erial
rand_s­erial = yes
privat­e_key = $dir/p­riv­ate­/ca­key.pem
RANDFILE = $dir/private/.rand
defaul­t_days = 365

C Openssl Generate Aes 256 Keyboard

defaul­t_c­rl_­days= 30
default_md = SHA256
policy = policy_any
email_­in_dn = no

Openssl Generate Aes 256 Key

name_opt = ca_default

Aes-256 Encryption

cert_opt = ca_default
copy_e­xte­nsions = none

C Openssl Generate Aes 256 Key Detection

[ policy_any ]
countr­yName = supplied
stateO­rPr­ovi­nceName = optional

Aes 256 Java

organi­zat­ionName = optional
organi­zat­ion­alU­nitName = optional
commonName = supplied
emailA­ddress = optional

FINAL NOTES

- All openssl commands were tested using OpenSSL version 1.1.1f
- All nmap commands were tested using nmap version 7.80. nmap is compiled using openssl librar­ies.
- The default format for almost all operations in openssl is PEM, however you can always specify a DER format using arguments or export to other formats with approp­riate commands indicated on the docume­nt.