Crypto Module

The crypto module provides implementations of various hashing algorithms as well as cryptography related functions.

These functions deal with cryptographic nonces.

For single server use only.

crypto.createNonce(): string

Creates a cryptographic nonce consisting of the first 32 bits of a timestamp and 64 bit of randomness.

The nonce is held in memory for approximately one hour by the server.

Returns the created nonce as base64-encoded string.

checkAndMarkNonce

crypto.checkAndMarkNonce(nonce): void

Checks if the nonce is valid and marks it as used.

Arguments

• nonce: string

  The nonce to check and mark.

Returns true if the supplied nonce was issued by the server and not marked before, otherwise false.

The following functions deal with generating random values.

rand

crypto.rand(): number

Generates a random integer that may be positive, negative or even zero.

Returns the generated number.

genRandomAlphaNumbers

crypto.genRandomAlphaNumbers(length): string

Generates a string of random alpabetical characters and digits.

Arguments

• length: number

  The length of the string to generate.

Returns the generated string.

genRandomNumbers

crypto.genRandomNumbers(length): string

Generates a string of random digits.

Arguments

• length: number

  The length of the string to generate.

Returns the generated string.

genRandomSalt

crypto.genRandomSalt(length): string

Generates a string of random (printable) ASCII characters.

Arguments

• length: number

  The length of the string to generate.

Returns the generated string.

genRandomBytes

crypto.genRandomBytes(length): Buffer

Generates a buffer of random bytes.

Arguments

• length: number

  The length of the buffer to generate.

Returns the generated buffer.

crypto.uuidv4(): string

Generates a random UUID v4 string.

Returns the generated UUID string.

These methods implement the JSON Web Token standard.

jwtEncode

crypto.jwtEncode(key, message, algorithm): string

Arguments

• key: string | null

  The secret cryptographic key to be used to sign the message using the given algorithm. Note that this function will raise an error if the key is omitted but the algorithm expects a key, and also if the algorithm does not expect a key but a key is provided (e.g. when using "none").

• message: string

  Message to be encoded as JWT. Note that the message will only be base64-encoded and signed, not encrypted. Do not store sensitive information in tokens unless they will only be handled by trusted parties.

• algorithm:

  Name of the algorithm to use for signing the message, e.g. "HS512".

Returns the JSON Web Token.

jwtDecode

crypto.jwtDecode(key, token, noVerify): string | null

Arguments

• key: string | null

  The secret cryptographic key that was used to sign the message using the algorithm indicated by the token. Note that this function will raise an error if the key is omitted but the algorithm expects a key.

  If the algorithm does not expect a key but a key is provided, the token will fail to verify.

• noVerify: boolean (Default: false)

  Whether verification should be skipped. If this is set to true the signature of the token will not be verified. Otherwise the function will raise an error if the signature can not be verified using the given key.

Returns the decoded JSON message or null if no token is provided.

jwtAlgorithms

A helper object containing the supported JWT algorithms. Each attribute name corresponds to a JWT alg and the value is an object with sign and verify methods.

jwtCanonicalAlgorithmName

crypto.jwtCanonicalAlgorithmName(name): string

A helper function that translates a JWT alg value found in a JWT header into the canonical name of the algorithm in jwtAlgorithms. Raises an error if no algorithm with a matching name is found.

Arguments

• name: string

  Algorithm name to look up.

Returns the canonical name for the algorithm.

md5

crypto.md5(message): string

Hashes the given message using the MD5 algorithm.

Arguments

• message: string

  The message to hash.

Returns the cryptographic hash.

sha1

crypto.sha1(message): string

Hashes the given message using the SHA-1 algorithm.

Arguments

• message: string

  The message to hash.

Returns the cryptographic hash.

Hashes the given message using the SHA-224 algorithm.

Arguments

• message: string

  The message to hash.

Returns the cryptographic hash.

sha256

crypto.sha256(message): string

Hashes the given message using the SHA-256 algorithm.

• message: string

  The message to hash.

Returns the cryptographic hash.

sha384

crypto.sha384(message): string

Hashes the given message using the SHA-384 algorithm.

Arguments

• message: string

  The message to hash.

Returns the cryptographic hash.

sha512

crypto.sha512(message): string

Hashes the given message using the SHA-512 algorithm.

Arguments

• message: string

  The message to hash.

Returns the cryptographic hash.

constantEquals

crypto.constantEquals(str1, str2): boolean

Compares two strings. This function iterates over the entire length of both strings and can help making certain timing attacks harder.

Arguments

• str1: string

  The first string to compare.

• str2: string

  The second string to compare.

Returns true if the strings are equal, false otherwise.

pbkdf2

crypto.pbkdf2(salt, password, iterations, keyLength): string

Generates a PBKDF2-HMAC-SHA1 hash of the given password.

Arguments

• salt: string

  The cryptographic salt to hash the password with.

• password: string

  The message or password to hash.

• iterations: number

  The number of iterations. This should be a very high number. OWASP recommended 64000 iterations in 2012 and recommends doubling that number every two years.

  When using PBKDF2 for password hashes it is also recommended to add a random value (typically between 0 and 32000) to that number that is different for each user.

• keyLength: number

  The key length.

Returns the cryptographic hash.

hmac

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

Generates an HMAC hash of the given message.

Arguments

• key: string

  The cryptographic key to use to hash the message.

• message:

  The message to hash.

• algorithm: string

  The name of the algorithm to use.

Returns the cryptographic hash.