Adds code

Author: EmptyChapter

src/index.ts

@@ -0,0 +1,201 @@
+import { pbkdf2Sync, randomBytes, timingSafeEqual } from "crypto";
+
+/** Defines type of HMAC digest algorythm. */
+type HmacDigest =
+  | "RSA-MD5"
+  | "RSA-RIPEMD160"
+  | "RSA-SHA1"
+  | "RSA-SHA1-2"
+  | "RSA-SHA224"
+  | "RSA-SHA256"
+  | "RSA-SHA3-224"
+  | "RSA-SHA3-256"
+  | "RSA-SHA3-384"
+  | "RSA-SHA3-512"
+  | "RSA-SHA384"
+  | "RSA-SHA512"
+  | "RSA-SHA512/224"
+  | "RSA-SHA512/256"
+  | "RSA-SM3"
+  | "blake2b512"
+  | "blake2s256"
+  | "id-rsassa-pkcs1-v1_5-with-sha3-224"
+  | "id-rsassa-pkcs1-v1_5-with-sha3-256"
+  | "id-rsassa-pkcs1-v1_5-with-sha3-384"
+  | "id-rsassa-pkcs1-v1_5-with-sha3-512"
+  | "md5"
+  | "md5-sha1"
+  | "md5WithRSAEncryption"
+  | "ripemd"
+  | "ripemd160"
+  | "ripemd160WithRSA"
+  | "rmd160"
+  | "sha1"
+  | "sha1WithRSAEncryption"
+  | "sha224"
+  | "sha224WithRSAEncryption"
+  | "sha256"
+  | "sha256WithRSAEncryption"
+  | "sha3-224"
+  | "sha3-256"
+  | "sha3-384"
+  | "sha3-512"
+  | "sha384"
+  | "sha384WithRSAEncryption"
+  | "sha512"
+  | "sha512-224"
+  | "sha512-224WithRSAEncryption"
+  | "sha512-256"
+  | "sha512-256WithRSAEncryption"
+  | "sha512WithRSAEncryption"
+  | "shake128"
+  | "shake256"
+  | "sm3"
+  | "sm3WithRSAEncryption"
+  | "ssl3-md5"
+  | "ssl3-sha1";
+
+/** Represents hashing error. */
+export class StringHashError extends Error {
+  /** Gets inner error. */
+  public inner?: Error;
+
+  /**
+   * Initializes a new instance of `StringHashError` class.
+   * @param message Error message.
+   * @param inner Inner error.
+   */
+  constructor(message?: string, inner?: Error) {
+    super(message);
+
+    this.inner = inner;
+  }
+}
+
+/** Defines properties of hashing options. */
+export type StringHashOptions = {
+  /** Gets hash signature (prefix). */
+  signature?: string;
+
+  /** Gets the HMAC digest algorythm. */
+  algorythm?: HmacDigest;
+
+  /** Gets salt length. */
+  saltLength?: number;
+
+  /** Gets hash length. */
+  hashLength?: number;
+
+  /** Gets the number of iteration. */
+  iterations?: number;
+};
+
+/** Defines properties and methods of `StringHasher`. */
+interface IStringHasher {
+  /** Gets hash signature (prefix). */
+  signature: string;
+
+  /** Gets algorythm */
+  algorythm: HmacDigest;
+
+  /** Gets salt length. */
+  saltLength: number;
+
+  /** Gets hash length. */
+  hashLength: number;
+
+  /** Gets buffer length (`saltLength` - `hashLength` - `signatureLength`). */
+  buffLength: number;
+
+  /** Gets iterations count. */
+  iterations: number;
+
+  /**
+   * Generates hash of the `value` string.
+   * @param value String to generate hash of.
+   * @returns Hash, generated of given string with following structure: `{signature}{hashBuff}{saltBuff}`.
+   */
+  generate(value: string): string;
+
+  /**
+   * Compares a plain-text `value` string to a hashed one.
+   * @param value Value string.
+   * @param hash Hash string.
+   * @returns `true` is hashes converge; `false` otherwise.
+   */
+  validate(value: string, hash: string): boolean;
+}
+
+/** Represents string hasher. */
+export class StringHasher implements IStringHasher {
+  public readonly signature: string = "sha512";
+  public readonly algorythm: HmacDigest = "sha512";
+  public readonly saltLength: number = 32;
+  public readonly hashLength: number = 128;
+  public readonly buffLength: number = 90;
+  public readonly iterations: number = 100000;
+
+  /**
+   * Initializes a new instance of `StringHasher` class.
+   * @param options Hashing options.
+   */
+  constructor(options?: StringHashOptions) {
+    if (!options) return;
+
+    // Change field values if options present.
+    if (options.signature) this.signature = options.signature.trim();
+    if (options.algorythm) this.algorythm = options.algorythm;
+    if (options.saltLength) this.saltLength = options.saltLength;
+    if (options.hashLength) this.hashLength = options.hashLength;
+    if (options.iterations) this.iterations = options.iterations;
+
+    // Validating values.
+    if (this.saltLength <= 0) throw new StringHashError("Salt length cannot be less than or equals zero.");
+    if (this.hashLength <= 0) throw new StringHashError("Hash length cannot be less than or equals zero.");
+    if (this.iterations < 1000) throw new StringHashError("Iterations count cannot be less than 1000.");
+    if (this.hashLength / 2 < this.saltLength)
+      throw new StringHashError("Salt length cannot be less than half of hash length.");
+    if ((this.hashLength / 3) * 2 < this.saltLength + this.signature.length)
+      throw new StringHashError("Salt length combined with signature length cannot be more than 2/3 of hash length.");
+
+    // Calculating raw hash buffer length.
+    this.buffLength = this.hashLength - this.saltLength - this.signature.length;
+  }
+
+  private generateSalt(): Buffer {
+    try {
+      return randomBytes(this.saltLength / 2);
+    } catch (e) {
+      throw new StringHashError("Unable to generate salt.", e as Error);
+    }
+  }
+
+  private generateHash(value: string, salt: Buffer): Buffer {
+    try {
+      return pbkdf2Sync(value, salt, this.iterations, this.buffLength / 2, this.algorythm);
+    } catch (e) {
+      throw new StringHashError("Unable to generate hash.", e as Error);
+    }
+  }
+
+  public generate(value: string): string {
+    const salt = this.generateSalt();
+    const hash = this.generateHash(value, salt);
+
+    return `${this.signature}${Buffer.concat([hash, salt]).toString("hex")}`;
+  }
+
+  public validate(value: string, hash: string): boolean {
+    if (value.length == 0 || hash.length != this.hashLength) return false;
+    if (this.signature != hash.substring(0, this.signature.length)) return false;
+
+    const hashStr = hash.substring(this.signature.length, this.hashLength - this.saltLength);
+    const saltStr = hash.substring(this.signature.length + this.buffLength);
+
+    const saltBuff = Buffer.from(saltStr, "hex");
+    const hashBuff = Buffer.from(hashStr, "hex");
+    const testBuff = this.generateHash(value, saltBuff);
+
+    return timingSafeEqual(hashBuff, testBuff);
+  }
+}