Cross-platform cryptography

General information and overview

This is a series of cryptography articles that will show how cryptography is done between different programming platforms. The sample programs do not attempt to be "secure" but explain how the crypto routines are compatible with other platforms.

I'm trying to serve a broad spectrum of programming languages and actually I have solutions for these frameworks: Java, PHP, C#, Javascript - CryptoJs, NodeJs Crypto, NodeJs node-forge, Python (for selected programs), Golang (for selected programs) and Dart (for selected programs) as long the functionality is available on the platform. You can test all programs with online compilers (except Dart as no online compiler can consume external libraries) to see what the output is and what happens when you change some parameters. For selected assignments there is a WebCrypto solution available, that will run in your (modern) browser. For very rare programs I provide an OpenSSL solution.

Wouldn't it be nice having a library that could be used cross-platform wide to get cryptographic tasks done? Yes and the library is still there, it is the Libsodium project and there are a lot of bindings available for all major frameworks. The algorithms in Libsodium differ from the other ones used in the cross-platform-project, therefore the Libsodium solutions are in an own section.

Sometimes you may have read about a "JWT" or "JWT token", that is short form of a JSON web token or JWT. That are standardized signature and encryption schemes for a defined data exchange between different systems and frameworks. I provide some JWT web token solutions.

A special chapter deals with the future of cryptography; and that is the Post Quantum Cryptography. Although the quantum computers are not on the market at the moment they will be there and cause catastrophic impacts on cryptography as they may been able to solve the RSA- and EC-curve problems and subsequently all RSA- and EC-curve encryption and signature become worthless. Visit the chapter PQC Post Quantum Cryptography at the end.

I'm providing a special article series about the migration of the (former) standard encryption module MCRYPT in PHP, that was available until version 5.6.x of PHP - newer versions of PHP come with OpenSSL as standard cryptography module. I'm giving examples how to migrate the algorithms Rijndael-128 (better known as "AES"), Rijndael-256, DES and Triple DES using the modes ECB, CBC and CTR and the zero padding or PKCS#7 padding. Visit the chapter MCRYPT migration at the end.

A lot of solutions run with the built-in cryptographic modules but especially the Python and Javascript-ones may need external libraries (pure Javascript will need e.g. "CryptoJs", NodeJs has a built-in "Crypto" library or you can use "node-forge").

General routines

Solution	Jav	PHP	C#	CJs	Ndc	Nfo	Web	Pyt	Go	Dar
generate a 32 byte long AES key	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅
generate a 16 byte long initvector	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅
generate a 12 byte long nonce	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅
Base64 encoding & decoding	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
binary data to a hex string & back	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
SHA256 hashing	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
MD-5 hashing	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅
HMAC 256 calculation	✅	✅	✅	✅	✅	✅	❌	✅	✅
PBKDF2 key derivation	✅	✅	✅	✅	✅	✅	❌	✅	✅
Generate RSA keys	see explanation
Generate Curve 25519 keys	✅	✅	✅	✅	✅	❌	❌
Generate Elliptic keys	see explanation

Jav=Java, PHP=PHP, C#=Csharp, CJs=Javascript with Crypto-JS, Ndc=NodeJs with Crypto, Nfo=NodeJs with forge, Web=WebCrypto, Pyt=Python, Go=Golang, Dar=Dart

AES string encryption

Solution	Jav	PHP	C#	CJs	Ndc	Nfo	Web	Pyt	Go	Dar
CBC-mode String Encryption	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅
CBC-mode String Decryption only	✅	✅	✅	✅	✅	✅	❌	❌	❌	❌
CBC-mode PBKDF2 String Encryption	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
CBC-mode PBKDF2 String Decryption only	✅	✅	✅	✅	✅	✅	❌	❌	❌	❌
CBC-mode PBKDF2 HMAC String Encryption	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅
CBC-mode passphrase String Encryption	✅	✅	✅	✅	✅	✅	❌	❌	❌	❌
GCM-mode String Encryption	✅	✅	✅	❌	✅	✅	❌	✅	✅	✅
GCM-mode PBKDF2 String Encryption	✅	✅	✅	❌	✅	✅	✅	✅	✅	✅
GCM-mode PBKDF2 AAD String Encryption	🔜	🔜	🔜	🔜	🔜	🔜	❌	🔜	🔜	🔜

Jav=Java, PHP=PHP, C#=Csharp, CJs=Javascript with Crypto-JS, Ndc=NodeJs with Crypto, Nfo=NodeJs with forge, Web=WebCrypto, Pyt=Python, Go=Golang, Dar=Dart

AES CBC special: tampering

Solution	Java	Explanation
AES CBC-mode tampering	✅	written in Java as it is for demonstration only

ChaCha20-Poly1305 encryption

Solution	Jav	PHP	C#	CJs	Ndc	Nfo	Web	Pyt	Go	Dar
ChaCha20-Poly1305 String encryption with random key	✅	✅	✅	❌	✅	❌	✅	✅	✅	✅

Jav=Java, PHP=PHP, C#=Csharp, CJs=Javascript with Crypto-JS, Ndc=NodeJs with Crypto, Nfo=NodeJs with forge, Web=WebCrypto, Pyt=Python, Go=Golang, Dar=Dart

DES and TripleDES encryption

Solution	Jav	PHP	C#	CJs	Ndc	Nfo	Web	Pyt	Go	Dar
DES CBC mode String encryption	✅	✅	✅	✅	✅	✅	🔜	✅	✅	✅
DES ECB mode String encryption	✅	✅	✅	✅	✅	✅	🔜	✅	✅	✅
TripleDES CBC mode String encryption	✅	✅	✅	✅	✅	✅	🔜	✅	✅	✅
TripleDES ECB mode String encryption	✅	✅	✅	✅	✅	✅	🔜	✅	✅	✅

Jav=Java, PHP=PHP, C#=Csharp, CJs=Javascript with Crypto-JS, Ndc=NodeJs with Crypto, Nfo=NodeJs with forge, Web=WebCrypto, Pyt=Python, Go=Golang, Dar=Dart

RSA encryption

Solution	Jav	PHP	C#	CJs	Ndc	Nfo	Web	Pyt	Go	Dar
RSA PKCS 1.5 padding String	✅	✅	✅	❌	✅	✅	❌	✅	✅	✅
RSA OEAP padding SHA-1 String	✅	✅	✅	❌	✅	✅	✅	✅	✅	✅
RSA OEAP padding SHA-1 String decryption only	✅	✅	✅	❌	✅	✅	✅
RSA OEAP padding SHA-256 String	✅	✅	✅	❌	✅	✅	✅	✅	✅	❌

Jav=Java, PHP=PHP, C#=Csharp, CJs=Javascript with Crypto-JS, Ndc=NodeJs with Crypto, Nfo=NodeJs with forge, Web=WebCrypto, Pyt=Python, Go=Golang, Dar=Dart

RSA signature with different padding modes

Solution	Jav	PHP	C#	CJs	Ndc	Nfo	Web	OSL	Pyt	Go	Dar
RSA String Signature PKCS#1.5 (full)	✅	✅	✅	❌	✅	✅	✅	✅	✅	✅	✅
RSA String Signature PKCS#1.5 Verification only	✅	✅	✅	❌	✅	✅	✅
RSA String Signature PSS (full)	✅	✅	✅	❌	✅	✅	✅	✅	✅	✅	✅
RSA encrypted private key example using signature with PKCS#1.5 padding	✅	✅	✅	❌	✅	✅	❌	❌	✅	✅	❌

Jav=Java, PHP=PHP, C#=Csharp, CJs=Javascript with Crypto-JS, Ndc=NodeJs with Crypto, Nfo=NodeJs with forge, Web=WebCrypto, Pyt=Python, OSL=OpenSSL, Go=Golang, Dar=Dart

RSA keys

Working with RSA key pairs can get tricky sometimes so I'm providing some more information about RSA keys:

page	information
How to generate RSA key pairs	creation of RSA key pairs with OpenSSL
How to convert RSA keys	convert keys between XML- and PEM-format
RSA sample keys	for my encryption and signature examples I'm using these keys
RSA key formats	explanation of the most used key formats
RSA encrypted private key	as you should protect your keys I recommend to work with encrypted private keys
RSA encrypted private key example using signature with PKCS#1.5 padding	example for the practical usage of encrypted keys
RSA encrypted private key - decrypt manually	how to parse an encrypted private key

RSA AES hybrid encryption

Solution	Jav	PHP	C#	CJs	Ndc	Nfo	Web	Pyt	Go	Dar
RSA AES CBC 256 hybrid encryption	✅	✅	✅	❌	✅	✅	❌	✅	✅	✅
RSA AES GCM 256 hybrid encryption	✅	✅	✅	❌	✅	✅	✅	✅	✅	✅

Jav=Java, PHP=PHP, C#=Csharp, CJs=Javascript with Crypto-JS, Ndc=NodeJs with Crypto, Nfo=NodeJs with forge, Web=WebCrypto, Pyt=Python, Go=Golang, Dar=Dart

Curve 25519 key exchange

Solution	Jav	PHP	C#	CJS	Ndc	Nfo	Pyt	Go
Curve 25519 key exchange & AES CBC mode 256 string encryption	✅	✅	✅	✅	✅	❌	✅	✅

Note: you need external libraries for this feature!

Elliptic curve keys

page	information
EC key generation	creation of EC key pairs with OpenSSL
EC sample keys	sample key pair for curve SECP256R1 = P-256 = PRIME256V1

Elliptic curve signature

Solution	Jav	PHP	C#	CJs	NdC	Nfo	Web	OSL	Pyt	Go	Dar
ECDSA String Signature IEEE-P1363 encoding	✅	✅	✅	❌	✅	❌	✅	❌	✅	✅	✅
ECDSA String Signature DER encoding	✅	✅	❌	❌	✅	❌	✅	✅	✅	✅	❌
ECDSA signature converter DER ← → IEEE P1363 encoding	✅	✅	❌	❌	✅	❌	✅	❌	❌	❌	❌

Jav=Java, PHP=PHP, C#=Csharp, CJs=Javascript with Crypto-JS, Ndc=NodeJs with Crypto, Nfo=NodeJs with forge, Web=WebCrypto, Pyt=Python, OSL=OpenSSL, Go=Golang, Dar=Dart

Libsodium solutions

Solution	Description	Jav	PHP	C#	Ndc	Web	Pyt	Go	Dar
Libsodium overview	general information about Libsodium ("NaCl", "Sodium") cryptography
generate a random key	see the examples in authenticated string encryption with a random key	✅	✅	✅	✅	✅	✅
generate a curve 25519 key pair	generate a curve X25519 private key and public key pair in Base64 encoding	✅	✅	✅	✅	❌
derive the curve X25519 public key from a secret key	generate the X25519 public key from a secret key in Base64 encoding	🔜	🔜	🔜	🔜	✅
generate a curve ED25519 key pair	generate a curve ED25519 private key and public key pair in Base64 encoding	✅	✅	✅	✅	✅	✅		✅
generate a curve ED25519 public key from a private key	generate an ED25519 public key from a private key in Base64 encoding	✅	✅	✅	✅	✅			✅
Argon 2 password derivation function	derives a password from a passphrase using the "modern" Argon2id algorithm	✅	✅	✅	✅	✅			✅
Argon 2 parameter	describes the parameters used in Argon 2 algorithm
ChaCha20-Poly1305 String encryption with random key	encrypts a string on basis of a randomly generated encryption key, using the ChaCha20 cipher for encryption and the Poly1305 MAC for authentication	✅	✅	✅	✅	✅	✅	✅	✅
Libsodium authenticated string encryption with a random key (secret box)	encrypts a string on basis of a randomly generated encryption key, using the XSalsa20 stream cipher for encryption and the Poly1305 MAC for authentication	✅	✅	✅	✅	✅	✅	✅	✅
Libsodium crypto box authenticated hybrid string encryption	encrypts a string on basis of a X25519 curve key exchange, using the XSalsa20 stream cipher for encryption and the Poly1305 MAC for authentication	✅	✅	✅	✅	✅	✅	✅	✅
Libsodium sealed box authenticated hybrid string encryption	encrypts a string on basis of a X25519 curve key exchange, using the XSalsa20 stream cipher for encryption and the Poly1305 MAC for authentication but without key exchange between the two partners	✅	✅	✅	✅	✅	✅	✅	✅
Libsodium string signature (detached) with a private-public key	uses an ED25519 curve signature	✅	✅	✅	✅	✅	✅	✅	✅

Jav=Java, PHP=PHP, C#=Csharp, CJs=Javascript with Crypto-JS, Ndc=NodeJs with Crypto, Nfo=NodeJs with forge, Web=WebCrypto, Pyt=Python, Go=Golang, Dar=Dart

OpenSSL solutions

Solution	Description
OpenSSL overview	general information about OpenSSL cryptography
Generate a RSA key pair	generate a RSA private key and public key in PEM encoding
Generate an EC key pair	generate an Elliptic curve (EC) private key and public key in PEM encoding
RSA file signature with PKCS#1.5 padding	the signature and verification is compatible with solutions in RSA string signature with PKCS#1.5 padding
RSA file signature with PSS padding	the signature and verification is compatible with solutions in RSA string signature with PSS padding
Elliptic curve file signature DER encoding	the signature and verification is compatible with solutions in ECDSA String Signature DER encoding

JWT JSON web token solutions

Solution	Description	Java	PHP	C#	NodeJS	Browser	Python	Go
JSON web token (JWT) overview	general information about JSON web token
structure of a JSON web token (JWT)	explains the general structure of a JWT
JSON web token JWA algorithms	standardized algorithms for JWT
JSON Web JWK keys	standardized key format for JWT
JSON web signature (JWS) using RS256 algorithm	sign a JWT with a RSA key, PKCS1.5 padding and SHA-256 hashing	✅	✅	✅	✅	✅	✅	✅
JSON web signature (JWS) using PS256 algorithm	sign a JWT with a RSA private key, RSASSA-PSS + MGF1 with SHA-256 and SHA-256 hashing	✅	✅	✅	✅	✅	✅	✅
JSON web signature (JWS) using RSxxx & PSxxx algorithms (verify only)	verify a JWT with a RSA public key, PKCS1.5 & SSA-PSS padding and SHA-256/384/512 hashing	❌	❌	❌	❌	🔜	❌	❌
JSON web encryption (JWE) using RSA-OAEP-256 with A256GCM algorithm	encrypt a JWT with a RSA key RSA-OAEP-256 and AES-256-GCM algorithm	✅	✅	✅	✅	✅	✅	✅

PQC Post Quantum Cryptography

Purpose	algorithm	Language
PQC overview		several
algorithms facts overview		several
PQC with Liboqs library overview	general overview about the OpenQuantumSafe library
liboqs algorithms facts overview	information about key, ciphertext & signature sizes	Java binding
Public key encryption	McEliece	Java
Public key encryption	NTRU	Java
key exchange (KEM)	Chrystals-Kyber	NodeJs
key exchange (KEM)	Sike	Java
key exchange (KEM)	Sike with Liboqs	Java
signature	FALCON	Python
signature	FALCON with Liboqs	Java binding
signature	Rainbow	Java
signature	Sphincs	Java

MCRYPT migration

Solution	mode	PHP OpenSSL	PHP phpseclib 3
MCRYPT migration overview
MCRYPT Rijndael-128 ECB	ECB mode	✅	✅
MCRYPT Rijndael-128 CBC	CBC mode	✅	✅
MCRYPT Rijndael-128 CTR	CTR mode	✅	✅
MCRYPT Rijndael-256 ECB	ECB mode	❌	✅
MCRYPT Rijndael-256 CBC	CBC mode	❌	✅
MCRYPT Rijndael-256 CTR	CTR mode	❌	✅
MCRYPT DES ECB	ECB mode	✅	✅
MCRYPT DES CBC	CBC mode	✅	✅
MCRYPT DES CTR	CTR mode	❌	✅
MCRYPT TDES ECB	ECB mode	✅	✅
MCRYPT TDES CBC	CBC mode	✅	✅
MCRYPT TDES CTR	CTR mode	❌	✅

Elliptic curve encryption

Solution	Java	PHP	C#	CryptoJS	NodeJS

not planned in future

Which platforms are supported at the moment?

I'm using an IDE for Java and PHP but for the other ones I'm using online compiler like https://replit.com/. Please don't ask if the programs will run on your system with a lower or higher version - just try it on your own.

A lot of solutions run with the built-in cryptographic modules but especially the Javascript-ones may need external libraries (pure Javascript will need e.g. "CryptoJs", NodeJs has a built-in "Crypto" or you can use "node-forge").

The few Javascript Webcrypto examples will run directly in your browser so you will need an actual one and Javascript is enabled.

Language	Online-compiler	framework version
C#	replit.com	Mono C# compiler version 6.8.0.123
C#	dotnetfiddle.net	.NET 4.7.2
C#	dotnetfiddle.net	.NET 5
C#	Bouncy Castle	version 1.89
Java	replit.com	OpenJDK Runtime Environment (build 11.0.6+10-post-Ubuntu-1ubuntu118.04.1)
Javascript CryptoJs	replit.com	node v12.16.1, crypto-js version 4.0.0
NodeJS Crypto	replit.com	node v12.16.1, openssl 1.1.1g
NodeJS node-forge	replit.com	node v12.16.1, node-forge version 0.10.0
OpenSSL		version 1.1.1g Windows x64
PHP	replit.com	PHP CLI 7.2.17-0ubuntu0.18.04.1 (cli) (built: Apr 18 2019 14:12:38)
PHP phpseclib	replit.com	version 3
Python	replit.com	version 3.8.2 (default, Feb 26 2020, 02:56:10)
Webcrypto	modern browser	tested in Firefox 91 (x64), Google Chrome 84.0.4147.135 (x86), Opera 70.0.3728.119
Go	replit.com	version go 1.14 linux/amd64
Go	goplay.space	version go 1.16.2
Dart	no online compiler available	tested on 2.13.1

Last update: Oct. 20th 2021

The website is published under: https://java-crypto.github.io/cross_platform_crypto//

If you are interested in much more information on cryptography in Java (and in German language) then visit my webpages http://javacrypto.bplaced.net and http://java-crypto.bplaced.net.