std:crypto

The std:crypto module provides functions for hashing, HMAC, UUID generation, and cryptographically secure random bytes. It is useful for security, authentication, and unique identifier generation.

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Functions

crypto.hash(algorithm: string, data: string): string

Computes the hash of data using the specified algorithm.

• Parameters:

  • algorithm (string): Hash algorithm ("md5", "sha1", "sha256")
  • data (string): The input string to hash

• Returns:

  • (string) Hexadecimal representation of the hash

Example:

local crypto = require("std:crypto")
print(crypto.hash("sha256", "hello world"))
-- "b94d27b9934d3e08a52e52d7da7dabfac484efe3..."

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crypto.hmac(algorithm: string, key: string, data: string): string

Generates a HMAC for data using key and the specified algorithm.

• Parameters:

  • algorithm (string): HMAC algorithm ("sha1", "sha256")
  • key (string): Secret key for HMAC
  • data (string): Input string to sign

• Returns:

  • (string) Hexadecimal representation of the HMAC

Example:

local crypto = require("std:crypto")
print(crypto.hmac("sha1", "secret", "message"))
-- "0caf649feee4953d87bf903ac1176c45e028df16"

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crypto.random_bytes(n: number): string

Generates n cryptographically secure random bytes.

• Parameters:

  • n (number): Number of bytes to generate

• Returns:

  • (string) Random bytes as a binary string

Example:

local crypto = require("std:crypto")
local rb = crypto.random_bytes(16)
print(rb)
-- (hex example) "\x7f\x3a\x9d\x2c\x4b\x12\x88\xef\x90\xab\xcd\x34\x56\x78\x9a\xbc"

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crypto.uuid(): string

Generates a UUID v4 string.

• Returns:
  • (string) UUID in standard string format

Example:

local crypto = require("std:crypto")
print(crypto.uuid())
-- "b0d8fa96-fc6b-43b2-bb02-55cfeaeb81d7"

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Supported Algorithms

Algorithm	Description	Output Length
md5	Message-Digest Algorithm 5	16 bytes
sha1	Secure Hash Algorithm 1	20 bytes
sha256	Secure Hash Algorithm 2 (256-bit)	32 bytes

Notes:

• All outputs are in hexadecimal format.
• md5 is fast but not recommended for cryptographic security.
• sha1 is more secure than md5 but considered weak for new systems.
• sha256 is the recommended default for most secure hashing needs.