const (

	// ModeArgon2i uses data-independent memory access, which is
	// preferred for password hashing and password-based key derivation
	// (e.g. hard drive encryption), but it's slower as it makes
	// more passes over the memory to protect from TMTO attacks.
	ModeArgon2i

	// ModeArgon2id is a hybrid of Argon2i and Argon2d, using a
	// combination of data-depending and data-independent memory accesses,
	// which gives some of Argon2i's resistance to side-channel cache timing
	// attacks and much of Argon2d's resistance to GPU cracking attacks.
	ModeArgon2id
)

const (
	// Version10 of the Argon2 algorithm. Deprecated: Use Version13 instead.
	Version10 = 0x10

	// Version13 of the Argon2 algorithm. Recommended.
	Version13 = 0x13
)

const (
	ARGON2_MIN_TIME = uint32(1)
	ARGON2_MAX_TIME = uint32(4294967295)
)

var (
	ErrOutputPtrNull         = Error("output pointer is null")
	ErrOutputTooShort        = Error("output is too short")
	ErrOutputTooLong         = Error("output is too long")
	ErrPwdTooShort           = Error("password is too short")
	ErrPwdTooLong            = Error("password is too long")
	ErrSaltTooShort          = Error("salt is too short")
	ErrSaltTooLong           = Error("salt is too long")
	ErrAdTooShort            = Error("associated data is too short")
	ErrAdTooLong             = Error("associated data is too long")
	ErrSecretTooShort        = Error("secret is too short")
	ErrSecretTooLong         = Error("secret is too long")
	ErrTimeTooSmall          = Error("time cost is too small")
	ErrTimeTooLarge          = Error("time cost is too large")
	ErrMemoryTooLittle       = Error("memory cost is too small")
	ErrMemoryTooMuch         = Error("memory cost is too large")
	ErrLanesTooFew           = Error("too few lanes")
	ErrLanesTooMany          = Error("too many lanes")
	ErrPwdPtrMismatch        = Error("password pointer is null, but password length is not 0")
	ErrSaltPtrMismatch       = Error("salt pointer is null, but salt length is not 0")
	ErrSecretPtrMismatch     = Error("secret pointer is null, but secret length is not 0")
	ErrAdPtrMismatch         = Error("associated data pointer is null, but ad length is not 0")
	ErrMemoryAllocationError = Error("memory allocation error")
	ErrFreeMemoryCbkNull     = Error("the free memory callback is null")
	ErrAllocateMemoryCbkNull = Error("the allocate memory callback is null")
	ErrIncorrectParameter    = Error("argon2_context context is null")
	ErrIncorrectType         = Error("there is no such version of argon2")
	ErrOutPtrMismatch        = Error("output pointer mismatch")
	ErrThreadsTooFew         = Error("not enough threads")
	ErrThreadsTooMany        = Error("too many threads")
	ErrMissingArgs           = Error("missing arguments")
	ErrEncodingFail          = Error("encoding failed")
	ErrDecodingFail          = Error("decoding failed")
	ErrThreadFail            = Error("threading failure")
	ErrDecodingLengthFail    = Error("some of encoded parameters are too long or too short")
	ErrVerifyMismatch        = Error("the password does not match the supplied hash")
)

type Config struct {
	// HashLength specifies the length of the resulting hash in Bytes.
	//
	// Must be > 0.
	HashLength uint32

	// SaltLength specifies the length of the resulting salt in Bytes,
	// if one of the helper methods is used.
	//
	// Must be > 0.
	SaltLength uint32

	// TimeCost specifies the number of iterations of argon2.
	//
	// Must be > 0.
	// If you use ModeArgon2i this should *always* be >= 3 due to TMTO attacks.
	// Additionally if you can afford it you might set it to >= 10.
	TimeCost uint32

	// MemoryCost specifies the amount of memory to use in Kibibytes.
	//
	// Must be > 0.
	MemoryCost uint32

	// Parallelism specifies the amount of threads to use.
	//
	// Must be > 0.
	Parallelism uint8

	// Mode specifies the hashing method used by argon2.
	//
	// If you're writing a server and unsure what to choose,
	// use ModeArgon2i with a TimeCost >= 3.
	Mode Mode

	// Version specifies the argon2 version to be used.
	Version Version
}

type Error string

type Mode uint32

type Raw struct {
	Config Config
	Salt   []byte
	Hash   []byte
}

type Version uint32