package srp

Import Path
	github.com/gotd/td/internal/crypto/srp (on go.dev)

Dependency Relation
	imports 8 packages, and imported by one package

Involved Source Files

	    hash.go
	    new_hash.go
	    pad.go
	  d srp.go
		Package srp contains implementation of Secure Remote Password protocol.
Package-Level Type Names (total 3, all are exported)

	/* sort exporteds by: alphabet | popularity */
	 type Answer (struct)
		Answer is result of SRP algorithm.

		Fields (total 2, both are exported)
			A []byte
				A parameter (see SRP)

			M1 []byte
				M1 parameter (see SRP)

		As Outputs Of (at least one exported)
			func SRP.Hash(password, srpB, random []byte, i Input) (Answer, error)

	 type Input (struct)
		Input is hashing algorithm parameters from server.
		
		Copy of tg.PasswordKdfAlgoSHA256SHA256PBKDF2HMACSHA512iter100000SHA256ModPow

		Fields (total 4, all are exported)
			G int
				Base (see SRP 2FA login¹)
				
				Links:
				 1) https://core.telegram.org/api/srp

			P []byte
				2048-bit modulus (see SRP 2FA login¹)
				
				Links:
				 1) https://core.telegram.org/api/srp

			Salt1 []byte
				One of two salts used by the derivation function (see SRP 2FA login¹)
				
				Links:
				 1) https://core.telegram.org/api/srp

			Salt2 []byte
				One of two salts used by the derivation function (see SRP 2FA login¹)
				
				Links:
				 1) https://core.telegram.org/api/srp

		As Inputs Of (at least 2, both are exported)
			func SRP.Hash(password, srpB, random []byte, i Input) (Answer, error)
			func SRP.NewHash(password []byte, i Input) (hash, newSalt []byte, _ error)

	 type SRP (struct)
		SRP is client implementation of Secure Remote Password protocol.
		
		See https://core.telegram.org/api/srp.

		Fields (only one, which is unexported)
			/* one unexported ... *//* one unexported: */
			random io.Reader
		Methods (total 12, in which 2 are exported)
			( SRP) Hash(password, srpB, random []byte, i Input) (Answer, error)
				Hash computes user password hash using parameters from server.
				
				See https://core.telegram.org/api/srp#checking-the-password-with-srp.

			( SRP) NewHash(password []byte, i Input) (hash, newSalt []byte, _ error)
				NewHash computes new user password hash using parameters from server.
				
				See https://core.telegram.org/api/srp#setting-a-new-2fa-password.
				
				TDLib implementation:
				See https://github.com/tdlib/td/blob/fa8feefed70d64271945e9d5fd010b957d93c8cd/td/telegram/PasswordManager.cpp#L57.
				
				TDesktop implementation:
				See https://github.com/telegramdesktop/tdesktop/blob/v3.4.8/Telegram/SourceFiles/core/core_cloud_password.cpp#L68.

			/* 10 unexporteds ... *//* 10 unexporteds: */
			( SRP) bigExp(x, y, m *big.Int) *big.Int
			( SRP) bigFromBytes(b []byte) *big.Int
			( SRP) computeXV(password, clientSalt, serverSalt []byte, g, p *big.Int) (x, v *big.Int)
				computeXV computes following numbers
				
				`x = PH2(password, salt1, salt2)`
				`v = pow(g, x) mod p`
				
				TDLib uses terms `clientSalt` for `salt1` and `serverSalt` for `salt2`.

			( SRP) hash(data ...[]byte) []byte
				The main hashing function H is sha256:
				
				H(data) := sha256(data)

			( SRP) pad256(b []byte) [256]byte
			( SRP) pad256FromBig(i *big.Int) (b [256]byte, r bool)
			( SRP) pbkdf2(ph1, salt1 []byte, n int) []byte
			( SRP) primary(password, salt1, salt2 []byte) []byte
				The primary password hashing function is defined as follows:
				
				PH1(password, salt1, salt2) := SH(SH(password, salt1), salt2)

			( SRP) saltHash(data, salt []byte) []byte
				The salting hashing function SH is defined as follows:
				
				SH(data, salt) := H(salt | data | salt)

			( SRP) secondary(password, salt1, salt2 []byte) []byte
				The secondary password hashing function is defined as follows:
				
				PH2(password, salt1, salt2) := SH(pbkdf2(sha512, PH1(password, salt1, salt2), salt1, 100000), salt2)

		As Outputs Of (at least one exported)
			func NewSRP(random io.Reader) SRP


Package-Level Functions (total 3, in which 1 is exported)

	 func NewSRP(random io.Reader) SRP
		NewSRP creates new SRP instance.

	/* 2 unexporteds ... *//* 2 unexporteds: */
	 func checkInput(g int, p *big.Int) error
	 func xor32(a, b [32]byte) (res [32]byte)

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