From 496d5b4ec7f5f4afae6199f928675d14d18de015 Mon Sep 17 00:00:00 2001 From: Wim Date: Sun, 20 Mar 2022 02:20:54 +0100 Subject: Add whatsappmulti buildflag for whatsapp with multidevice support (whatsapp) --- .../Rhymen/go-whatsapp/crypto/hkdf/hkdf.go | 47 ++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 vendor/github.com/Rhymen/go-whatsapp/crypto/hkdf/hkdf.go (limited to 'vendor/github.com/Rhymen/go-whatsapp/crypto/hkdf/hkdf.go') diff --git a/vendor/github.com/Rhymen/go-whatsapp/crypto/hkdf/hkdf.go b/vendor/github.com/Rhymen/go-whatsapp/crypto/hkdf/hkdf.go new file mode 100644 index 00000000..3d7361f0 --- /dev/null +++ b/vendor/github.com/Rhymen/go-whatsapp/crypto/hkdf/hkdf.go @@ -0,0 +1,47 @@ +/* +HKDF is a simple key derivation function (KDF) based on +a hash-based message authentication code (HMAC). It was initially proposed by its authors as a building block in +various protocols and applications, as well as to discourage the proliferation of multiple KDF mechanisms. +The main approach HKDF follows is the "extract-then-expand" paradigm, where the KDF logically consists of two modules: +the first stage takes the input keying material and "extracts" from it a fixed-length pseudorandom key, and then the +second stage "expands" this key into several additional pseudorandom keys (the output of the KDF). +*/ +package hkdf + +import ( + "crypto/sha256" + "fmt" + "golang.org/x/crypto/hkdf" + "io" +) + +/* +Expand expands a given key with the HKDF algorithm. +*/ +func Expand(key []byte, length int, info string) ([]byte, error) { + var h io.Reader + if info == "" { + /* + Only used during initial login + Pseudorandom Key is provided by server and has not to be created + */ + h = hkdf.Expand(sha256.New, key, []byte(info)) + } else { + /* + Used every other time + Pseudorandom Key is created during kdf.New + This is the normal that crypto/hkdf is used + */ + h = hkdf.New(sha256.New, key, nil, []byte(info)) + } + out := make([]byte, length) + n, err := io.ReadAtLeast(h, out, length) + if err != nil { + return nil, err + } + if n != length { + return nil, fmt.Errorf("new key to short") + } + + return out, nil +} -- cgit v1.2.3