github.com/moqsien/xraycore@v1.8.5/proxy/vmess/aead/kdf.go (about)

     1  package aead
     2  
     3  import (
     4  	"crypto/hmac"
     5  	"crypto/sha256"
     6  	"hash"
     7  )
     8  
     9  type hash2 struct {
    10  	hash.Hash
    11  }
    12  
    13  func KDF(key []byte, path ...string) []byte {
    14  	hmacf := hmac.New(sha256.New, []byte(KDFSaltConstVMessAEADKDF))
    15  
    16  	for _, v := range path {
    17  		first := true
    18  		hmacf = hmac.New(func() hash.Hash {
    19  			if first {
    20  				first = false
    21  				return hash2{hmacf}
    22  			}
    23  			return hmacf
    24  		}, []byte(v))
    25  	}
    26  	hmacf.Write(key)
    27  	return hmacf.Sum(nil)
    28  }
    29  
    30  func KDF16(key []byte, path ...string) []byte {
    31  	r := KDF(key, path...)
    32  	return r[:16]
    33  }