gnablib

A lean, zero dependency library to provide a useful base for your project. Checksums, cryptography, codecs, date-times, error-checking-codes, logging, pseudorandom number generation. The tools you need for any project. Secure build pipeline, provenance signed and typed.

Contents

• Installation
• License
• Features:
  • Augmented Backus-Naur Form
  • Checksum/Hashsum
  • Command Line Interface (arguments, colour, text style)
  • Codecs
  • Symmetric Encryption
  • Secure Hashing
  • Key derivation functions
  • Message Authentication Codes
  • EXtendable-Output Functions
  • DateTime
  • Error Correction Code
  • Endian
  • Primitive Types
  • Seedable PseudoRandom number generators
  • RegExp tools
  • Run time tools (environment vars, logging, stack traces)

Installation

This module is available through NPM. There are no install scripts, decrease your risk by explicitly preventing (--ignore-scripts)

(pnpm|npm) install gnablib --ignore-scripts

To verify provenance:

npm audit signatures

Details

Augmented Backus-Naur Form /rfc5234

• Operators
• Definition of core rules

Algorithms

• Weighted Random Sampling
• Thomson NFA (1968) solver

Checksum/Hashsum

A checksum; can be used to prevent/identify accidental changes.

The Luhn algorithm is also support, which only works on integers/numerical digits (eg. credit cards, SI numbers)

A hash; maps some data to another, often used for hash tables, or to speed up comparison. We use the term hashsum to distinguish from cryptographic-hashes (although MD5 and SHA1 were once cryptographically safe)

Command Line Interface (cli)

• Argument and option parsing
• Foreground, background color (8 color, 213 color, 16M colors)
• Underline, bold, faint, italic, blink, invert, hide, strike-through, overline text styles
• Terminal controls & style (cursor move, screen/line clear)

Codec

• ASCII85
• Base32, zBase32, Base32Hex, Crockford32
• Base64, Base64url, B64
• bfloat16
• Densely Packed Decimal
• Hex
• IEEE754 Binary
• Proquint
• QuotedPrintable
• ROT13, ROT13.5, ROT47
• Scream
• URI
• UTF8
• uuencode
• UUID
• YEnc

Crypto

Block

• Cipher Block Chaining (CBC))
• Cipher FeedBack (CFB))
• Counter (CTR))
• Electronic CodeBook (ECB))
• Output FeedBack (OFB))

CBC or CTR are recommended by Niels Ferguson and Bruce Schneier. ECB should not be used.

Padding

• ANSI X9.23 / ISO 10126 padding
• ISO 7816-4 padding
• ISO 9797-1 padding 2
• PKCS#7 / PKCS#5 padding
• Zero / Null padding

Symmetric Encryption

Secure Hash

Cryptography hash functions that have the properties:

• Finding an input string that matches a hash value (pre-image) is hard
• Finding a pair of messages that generate the same hash value (collision) is hard

† No longer considered cryptographically safe

Key Derivation Function (KDF)

A cryptographic algorithm that derives one or more secret keys from a secret value. Can be used to stretch keys (make them longer), or obtain a key in a particular format (eg making a key a fixed length)

• HKDF
• PBKDF2 pbkdf2_hmac_sha1, pbkdf2_hmac_sha256, pbkdf2_hmac_sha512

Message Authentication Code (MAC)

Also known as an authentication tag, a short piece of information to authenticate a message. Protect integrity, and authenticity.

EXtendable-Output Function (XOF)

A secure hash that can produce output of any desired length.

DateTime

• Year, Month, Day
• Hour, Minute, Second, Millisecond, Microsecond
• DateTimeLocal, DateTimeUtc, DateOnly, TimeOnly
• Duration, DurationExact
• DateTime*.lt|lte|eq|gt|gte|neq - Compare two date-times
• DateTime*.add|sub - Add or subtract Duration|DurationExact from a date-time
• DateTime.diff|diffExact - Get the difference between two dates in y/m/d/h/ or d/h/*

Error Correction Codes

• Reed Solomon

Endian

• Convert between big (BE) and little (LE) Endian encoding 16/32/64/128 bits, or a stream of bytes.
• Detects platform endianness

Big endian is closer to the way we write numbers left-to-right in English. 1726 = 1x1000, 7x100, 2x10, 6x1

Little endian is the dominant ordering for processor architectures including; x86 and RISC-V, ARM can be either but defaults to little. Famous big endian processors include PDP-10, Motorola 68000 series (early Macintosh, Amiga, Atari, Sega), IBM Z and SPARC, which can be either but defaults to big.

Primitive

• BitReader / BitWriter
• Fixed TypedArray
• Lazy
• Network CIDR, IPv4
• Readonly TypedArray
• Scaling TypedArray
• StringBuilder
• WindowStr
• 16 bit: uint (U16)
• 32 bit: uint (U32), mutable uint (U32Mut), mutable uint array (U32MutArray)
• 64 bit: int (I64), uint (U64), mutable int (I64Mut), mutable uint (U64Mut), mutable uint array (U64MutArray)
• 128 bit: uint (U128), mutable uint (U128Mut)
• 256 bit: uint (U256)
• 512 bit: uint (U512)

Extensions:

• Bit (countBitsSet, lsbMask, reverse, countLeadZeros, nextPow2)
• Float (parseDec)
• Int (parseDec, parseHex, parseCsv)
• String (splitChars, splitLen, reverse, padStart, filter, ctEq, ctSelect)
• Uint (parseDec, parseHex, sign8, sign16, sign32, glScaleSize, toGlScaleBytes, fromGlScaleBytes)
• Uint8Array (toGlBytes, ctEq, ctSelect, incrBE, lShiftEq, xorEq)

PseudoRandom number generators (PRNG)

Good PRNGs

Use one of these if you can, alphabetically sorted. gjrand32b is only somewhat official and doesn't have a lot of testing. B=Bytes, b=bits

‡: Use U64 library to exceed JS 32bit integer constraint (may be slower)

U16 : [0 - 32767 | 0xFFFF]
U31 : [0 - 2147483647 | 0x7FFFFFFF]
U32 : [0 - 4294967295 | 0xFFFFFFFF]
U64 : [0 - 18446744073709551615 | 0xFFFFFFFFFFFFFFFF]

Poor PRNGs

Best not to use these, there are some dragons in these waters (so if you're choosing, be aware of the limitations). However, you might have a compatibility constraint (or love the name "Mersenne Twister").

Bad PRNGs

If you're curious about the lineage, or need for compatibility with an old decision, but don't chose one of these. If you're already using one of these, consider migrating.

RegExp

• RegExp escape string

Run time

• Configuration (including collecting from environment variables)
• Structured logging
• Normalize stack entries, and stack traces across engines, with colors

License

Copyright © 2022-2025 gnablib contributors

MPL-1.1