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orpheion / repository
The jsbn library is a fast, portable implementation of large-number math in pure JavaScript
The jsbn library is a pure JavaScript implementation of arbitrary-precision
integer arithmetic.
The API for the jsbn library closely resembles that of the
java.math.BigInteger class in Java.
For example:
x = new BigInteger("abcd1234", 16);
y = new BigInteger("beef", 16);
z = x.mod(y);
alert(z.toString(16));
will print b60c.
jsbn.js - basic BigInteger implementation, just enough for RSA encryption and not much more.jsbn2.js - the rest of the library, including most public BigInteger methods.rsa.js - implementation of RSA encryption, does not require jsbn2.js.rsa2.js - rest of RSA algorithm, including decryption and keygen.rng.js - rudimentary entropy collector and RNG interface, requires a PRNG backend to define prng_newstate().prng4.js - ARC4-based PRNG backend for rng.js, very small.base64.js - Base64 encoding and decoding routines.The demo encrypts strings directly using PKCS#1 encryption-style padding (type 2), which is currently the only supported format. To show interoperability with a potential OpenSSL-based backend that decrypts strings, try the following on any system with the OpenSSL command line tool installed:
Generate a new public/private keypair:
$ openssl genrsa -out key.pem
Generating RSA private key, 512 bit long modulus
..++++++++++++
..............++++++++++++
e is 65537 (0x10001)
$
Extract the modulus from your key:
$ openssl rsa -in key.pem -noout -modulus
Modulus=DA3BB4C40E3C7E76F7DBDD8BF3DF0714CA39D3A0F7F9D7C2E4FEDF8C7B28C2875F7EB98950B22AE82D539C1ABC1AB550BA0B2D52E3EF7BDFB78A5E817D74BBDB
$
Go to the RSA Encryption demo and paste the modulus value into the "Modulus (hex)" field at the bottom.
Make sure the value in the "Public exponent" field is "10001", or whatever value your public key uses.
Type in a short string (e.g. testing) into the "Plaintext (string)" field
and click on "encrypt". The result should appear in the "Ciphertext"
fields.
Copy the base64 version of the ciphertext and paste it as the input of the following command:
$ openssl base64 -d | openssl rsautl -inkey key.pem -decrypt
1JW24UMKntVhmmDilAYC1AjLxgiWHBzTzZsCVAejLjVri92abLHkSyLisVyAdYVr
fiS7FchtI9vupe9JF/m3Kg==
Hit ctrl-D or whatever your OS uses for end-of-file. Your original plaintext should appear:
testing$
Since jsbn is pure JavaScript, its performance will depend on the hardware as
well as the quality of the JavaScript execution environment, but will be
considerably slower than native implementations in languages such as C/C++ or
Java.
On a 1GHz Intel PC running Mozilla:
On similar hardware, running IE6:
Timing measurements, especially under IE, appear to have limited precision for faster operations.
jsbn is released under a BSD license.
See LICENSE for details.
Selected from shared topics, language and repository description—not editorial ratings.
andyperlitch /
The jsbn library is a fast, portable implementation of large-number math in pure JavaScript, enabling public-key crypto and other applications on desktop and mobile browsers.