diff options
Diffstat (limited to 'vendor/github.com/Rhymen/go-whatsapp/crypto/hkdf/hkdf.go')
-rw-r--r-- | vendor/github.com/Rhymen/go-whatsapp/crypto/hkdf/hkdf.go | 52 |
1 files changed, 0 insertions, 52 deletions
diff --git a/vendor/github.com/Rhymen/go-whatsapp/crypto/hkdf/hkdf.go b/vendor/github.com/Rhymen/go-whatsapp/crypto/hkdf/hkdf.go deleted file mode 100644 index e0be0587..00000000 --- a/vendor/github.com/Rhymen/go-whatsapp/crypto/hkdf/hkdf.go +++ /dev/null @@ -1,52 +0,0 @@ -/* -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/hmac" - "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) { - if info == "" { - keyBlock := hmac.New(sha256.New, key) - var out, last []byte - - var blockIndex byte = 1 - for i := 0; len(out) < length; i++ { - keyBlock.Reset() - //keyBlock.Write(append(append(last, []byte(info)...), blockIndex)) - keyBlock.Write(last) - keyBlock.Write([]byte(info)) - keyBlock.Write([]byte{blockIndex}) - last = keyBlock.Sum(nil) - blockIndex += 1 - out = append(out, last...) - } - return out[:length], nil - } else { - 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[:length], nil - } -} |