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Raised by Encoding and String methods when the source encoding is incompatible with the target encoding.

No documentation available

Description

An FFI closure wrapper, for handling callbacks.

Example

closure = Class.new(Fiddle::Closure) {
  def call
    10
  end
}.new(Fiddle::TYPE_INT, [])
   #=> #<#<Class:0x0000000150d308>:0x0000000150d240>
func = Fiddle::Function.new(closure, [], Fiddle::TYPE_INT)
   #=> #<Fiddle::Function:0x00000001516e58>
func.call
   #=> 10

Generic error class for Fiddle

standard dynamic load exception

A base class for objects representing a C structure

Wrapper for arrays within a struct

A pointer to a C structure

The base exception for JSON errors.

This exception is raised if the required unicode support is missing on the system. Usually this means that the iconv library is not installed.

OpenSSL::Digest allows you to compute message digests (sometimes interchangeably called “hashes”) of arbitrary data that are cryptographically secure, i.e. a Digest implements a secure one-way function.

One-way functions offer some useful properties. E.g. given two distinct inputs the probability that both yield the same output is highly unlikely. Combined with the fact that every message digest algorithm has a fixed-length output of just a few bytes, digests are often used to create unique identifiers for arbitrary data. A common example is the creation of a unique id for binary documents that are stored in a database.

Another useful characteristic of one-way functions (and thus the name) is that given a digest there is no indication about the original data that produced it, i.e. the only way to identify the original input is to “brute-force” through every possible combination of inputs.

These characteristics make one-way functions also ideal companions for public key signature algorithms: instead of signing an entire document, first a hash of the document is produced with a considerably faster message digest algorithm and only the few bytes of its output need to be signed using the slower public key algorithm. To validate the integrity of a signed document, it suffices to re-compute the hash and verify that it is equal to that in the signature.

You can get a list of all digest algorithms supported on your system by running this command in your terminal:

openssl list -digest-algorithms

Among the OpenSSL 1.1.1 supported message digest algorithms are:

Each of these algorithms can be instantiated using the name:

digest = OpenSSL::Digest.new('SHA256')

“Breaking” a message digest algorithm means defying its one-way function characteristics, i.e. producing a collision or finding a way to get to the original data by means that are more efficient than brute-forcing etc. Most of the supported digest algorithms can be considered broken in this sense, even the very popular MD5 and SHA1 algorithms. Should security be your highest concern, then you should probably rely on SHA224, SHA256, SHA384 or SHA512.

Hashing a file

data = File.read('document')
sha256 = OpenSSL::Digest.new('SHA256')
digest = sha256.digest(data)

Hashing several pieces of data at once

data1 = File.read('file1')
data2 = File.read('file2')
data3 = File.read('file3')
sha256 = OpenSSL::Digest.new('SHA256')
sha256 << data1
sha256 << data2
sha256 << data3
digest = sha256.digest

Reuse a Digest instance

data1 = File.read('file1')
sha256 = OpenSSL::Digest.new('SHA256')
digest1 = sha256.digest(data1)

data2 = File.read('file2')
sha256.reset
digest2 = sha256.digest(data2)

Generic error, common for all classes under OpenSSL module

Generic Error for all of OpenSSL::BN (big num)

General error for openssl library configuration files. Including formatting, parsing errors, etc.

Document-class: OpenSSL::HMAC

OpenSSL::HMAC allows computing Hash-based Message Authentication Code (HMAC). It is a type of message authentication code (MAC) involving a hash function in combination with a key. HMAC can be used to verify the integrity of a message as well as the authenticity.

OpenSSL::HMAC has a similar interface to OpenSSL::Digest.

HMAC-SHA256 using one-shot interface

key = "key"
data = "message-to-be-authenticated"
mac = OpenSSL::HMAC.hexdigest("SHA256", key, data)
#=> "cddb0db23f469c8bf072b21fd837149bd6ace9ab771cceef14c9e517cc93282e"

HMAC-SHA256 using incremental interface

data1 = File.read("file1")
data2 = File.read("file2")
key = "key"
digest = OpenSSL::Digest.new('SHA256')
hmac = OpenSSL::HMAC.new(key, digest)
hmac << data1
hmac << data2
mac = hmac.digest
No documentation available

This class works in conjunction with Psych::Parser to build an in-memory parse tree that represents a YAML document.

Example

parser = Psych::Parser.new Psych::TreeBuilder.new
parser.parse('--- foo')
tree = parser.handler.root

See Psych::Handler for documentation on the event methods used in this class.

UDP/IP address information used by Socket.udp_server_loop.

No documentation available

The superclass for all exceptions raised by Ruby/zlib.

The following exceptions are defined as subclasses of Zlib::Error. These exceptions are raised when zlib library functions return with an error status.

Subclass of Zlib::Error when zlib returns a Z_DATA_ERROR.

Usually if a stream was prematurely freed.

Subclass of Zlib::Error

When zlib returns a Z_MEM_ERROR, usually if there was not enough memory.

Subclass of Zlib::Error when zlib returns a Z_BUF_ERROR.

Usually if no progress is possible.

Subclass of Zlib::Error

When zlib returns a Z_VERSION_ERROR, usually if the zlib library version is incompatible with the version assumed by the caller.

Zlib::GzipReader is the class for reading a gzipped file. GzipReader should be used as an IO, or -IO-like, object.

Zlib::GzipReader.open('hoge.gz') {|gz|
  print gz.read
}

File.open('hoge.gz') do |f|
  gz = Zlib::GzipReader.new(f)
  print gz.read
  gz.close
end

Method Catalogue

The following methods in Zlib::GzipReader are just like their counterparts in IO, but they raise Zlib::Error or Zlib::GzipFile::Error exception if an error was found in the gzip file.

Be careful of the footer of the gzip file. A gzip file has the checksum of pre-compressed data in its footer. GzipReader checks all uncompressed data against that checksum at the following cases, and if it fails, raises Zlib::GzipFile::NoFooter, Zlib::GzipFile::CRCError, or Zlib::GzipFile::LengthError exception.

The rest of the methods are adequately described in their own documentation.

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