OathAlgorithm

public enum OathAlgorithm : String, CaseIterable, Codable, Sendable

Enum representing the different HMAC algorithms supported for OATH credential generation.

OATH algorithms use HMAC (Hash-based Message Authentication Code) with different hash functions to generate one-time passwords. The choice of algorithm affects both security strength and computational requirements.

Algorithm Comparison

Algorithm Security Performance Digest Size Recommendation
SHA-1 Legacy Fastest 160 bits Legacy support only
SHA-256 Strong Moderate 256 bits Industry standard
SHA-512 Strongest Slowest 512 bits High security needs

Standards Compliance

All algorithms implement the HMAC construction as defined in RFC 2104, and are compatible with RFC 4226 (HOTP) and RFC 6238 (TOTP) specifications.

  • SHA-1 HMAC algorithm (legacy).

    Security Note: SHA-1 is cryptographically weak and should only be used for legacy system compatibility. New implementations should use SHA-256 or SHA-512.

    Declaration

    Swift

    case sha1 = "SHA1"

  • SHA-256 HMAC algorithm.

    The standard algorithm for new OATH implementations. Provides a strong balance of security with good performance characteristics.

    Declaration

    Swift

    case sha256 = "SHA256"

  • SHA-512 HMAC algorithm.

    Provides the highest level of cryptographic security but with increased computational overhead. Suitable for high-security environments.

    Declaration

    Swift

    case sha512 = "SHA512"

  • Creates an OathAlgorithm from a string representation.

    Throws

    OathError.invalidAlgorithm if the string doesn’t match any known algorithm.

    Declaration

    Swift

    public static func fromString(_ string: String) throws -> OathAlgorithm

    Parameters

    string

    The string representation (case-insensitive).

    Return Value

    The corresponding OathAlgorithm.