crypto 2.0.3 crypto: ^2.0.3 copied to clipboard
Library of cryptographic functions.
Cryptographic hashing functions for Dart #
A set of cryptographic hashing functions implemented in pure Dart
The following hashing algorithms are supported:
- SHA-1
- SHA-256
- MD5
- HMAC (i.e. HMAC-MD5, HMAC-SHA1, HMAC-SHA256)
Usage #
Digest on a single input #
To hash a list of bytes, invoke the convert
method on the
sha1
, sha256
or md5
objects.
import 'package:crypto/crypto.dart';
import 'dart:convert'; // for the utf8.encode method
void main() {
var bytes = utf8.encode("foobar"); // data being hashed
var digest = sha1.convert(bytes);
print("Digest as bytes: ${digest.bytes}");
print("Digest as hex string: $digest");
}
Digest on chunked input #
If the input data is not available as a single list of bytes, use the chunked conversion approach.
Invoke the startChunkedConversion
method
to create a sink for the input data. On the sink, invoke the add
method for each chunk of input data, and invoke the close
method
when all the chunks have been added. The digest can then be retrieved
from the Sink<Digest>
used to create the input data sink.
import 'dart:convert';
import 'package:crypto/crypto.dart';
import 'package:crypto/src/digest_sink.dart';
void main() {
var firstChunk = utf8.encode("foo");
var secondChunk = utf8.encode("bar");
var ds = new DigestSink();
var s = sha1.startChunkedConversion(ds);
s.add(firstChunk);
s.add(secondChunk); // call `add` for every chunk of input data
s.close();
var digest = ds.value;
print("Digest as bytes: ${digest.bytes}");
print("Digest as hex string: $digest");
}
The above example uses the DigestSink
class that comes with the
crypto package. Its value
property retrieves the last Digest
that was added to it, which is fine for this purpose since only one
Digest
is added to it when the data sink's close
method was
invoked.
HMAC #
Create an instance of the Hmac
class with the hash function
and secret key being used. The object can then be used like the other
hash calculating objects.
import 'dart:convert';
import 'package:crypto/crypto.dart';
import 'package:crypto/src/digest_sink.dart';
void main() {
var key = utf8.encode('p@ssw0rd');
var bytes = utf8.encode("foobar");
var hmacSha256 = new Hmac(sha256, key); // HMAC-SHA256
var digest = hmacSha256.convert(bytes);
print("HMAC digest as bytes: ${digest.bytes}");
print("HMAC digest as hex string: $digest");
}
Disclaimer #
Support for this library is given as best effort.
This library has not been reviewed or vetted by security professionals.
Features and bugs #
Please file feature requests and bugs at the issue tracker.