os-datablock.md

os_datablock

Summary

The os_datablock component is OpenSecurity's utility data block. It offers a group of local data-processing callbacks such as Base64, compression, hashes, ROT13, and BCrypt helpers, and it also mounts a bundled filesystem environment named datablock.

Availability

• Repository: opensecurity
• Component name: os_datablock
• Typical host: placed OpenSecurity data block

Usage

local component = require("component")
local data = component.os_datablock

if not data then
  error("os_datablock component not installed")
end

Filesystem Environment

When connected to a computer context, the block also exposes a bundled filesystem environment named datablock.

Data Limits And Energy

Several byte-array callbacks pass through a shared limiter:

• hard size limit: Settings.get().dataCardHardLimit()
• soft size limit: Settings.get().dataCardSoftLimit()
• timeout pause for oversized but still allowed data: Settings.get().dataCardTimeout()

Shared failure modes for callbacks using that limiter:

• oversized input: data size limit exceeded
• insufficient power: not enough energy

Energy classes used by the source:

• complex-cost callbacks:
  • encode64
  • decode64
  • deflate
  • inflate
• simple-cost callbacks:
  • sha256
  • md5
  • crc32
• no limiter and no explicit power draw:
  • rot13
  • bCryptHash
  • bCryptCheck

API

greet

• Syntax: data.greet()
• Returns: string
• Purpose: Returns the built-in OpenSecurity greeting.

getLimit

• Syntax: data.getLimit()
• Returns: number
• Purpose: Returns the hard maximum byte size accepted by the limited callbacks.

encode64

• Syntax: data.encode64(input)
• Returns: string
• Purpose: Base64-encodes the supplied byte string.

Parameters:

• input:string|byte[]

Behavior:

• The return value is a byte string containing ASCII Base64 text.

decode64

• Syntax: data.decode64(input)
• Returns: string
• Purpose: Base64-decodes the supplied byte string.

Parameters:

• input:string|byte[]

Behavior:

• The return value is the decoded raw byte string.

deflate

• Syntax: data.deflate(input)
• Returns: string
• Purpose: Compresses the supplied bytes using deflate.

Parameters:

• input:string|byte[]

inflate

• Syntax: data.inflate(input)
• Returns: string
• Purpose: Inflates a previously deflated byte string.

Parameters:

• input:string|byte[]

sha256

• Syntax: data.sha256(input)
• Returns: string
• Purpose: Computes the SHA-256 digest.

Parameters:

• input:string|byte[]

Behavior:

• The result is returned in binary format, not hexadecimal text.

md5

• Syntax: data.md5(input)
• Returns: string
• Purpose: Computes the MD5 digest.

Parameters:

• input:string|byte[]

Behavior:

• The result is returned in binary format.

crc32

• Syntax: data.crc32(input)
• Returns: string
• Purpose: Computes the CRC-32 digest.

Parameters:

• input:string|byte[]

Behavior:

• The result is returned in binary format.

rot13

• Syntax: data.rot13(input)
• Returns: string
• Purpose: Applies ROT13 to alphabetic ASCII characters.

Parameters:

• input:string

Behavior:

• Only letters A-Z and a-z are rotated.
• All other characters are copied unchanged.

bCryptHash

• Syntax: data.bCryptHash(plaintext[, rounds])
• Returns: string
• Purpose: Computes a BCrypt hash string.

Parameters:

• plaintext:string
• rounds:number optional

Behavior:

• Default rounds value is 10.
• The implementation clamps rounds to 4 through 15.
• The returned value is the standard BCrypt text hash.

bCryptCheck

• Syntax: data.bCryptCheck(plaintext, hash)
• Returns: boolean
• Purpose: Verifies plaintext against a BCrypt hash string.

Parameters:

• plaintext:string
• hash:string

Example

local digest = data.sha256("hello")
local encoded = data.encode64("secret")
local compressed = data.deflate("compress me")
local hash = data.bCryptHash("password", 12)

print(#digest, encoded, data.bCryptCheck("password", hash))
print(data.rot13("uryyb jbeyq"))

Related

• component
• os_cardwriter