// Copyright (C) 2019 Storj Labs, Inc. // See LICENSE for copying information. package encryption import ( "crypto/hmac" "crypto/sha256" "github.com/zeebo/errs" "golang.org/x/crypto/argon2" "storj.io/common/memory" "storj.io/common/storj" ) func sha256hmac(key, data []byte) ([]byte, error) { h := hmac.New(sha256.New, key) if _, err := h.Write(data); err != nil { return nil, err } return h.Sum(nil), nil } // DeriveRootKey derives a root key for some path using the salt for the bucket and // a password from the user. See the password key derivation design doc. func DeriveRootKey(password, salt []byte, path storj.Path, argon2Threads uint8) (*storj.Key, error) { mixedSalt, err := sha256hmac(password, salt) if err != nil { return nil, err } pathSalt, err := sha256hmac(mixedSalt, []byte(path)) if err != nil { return nil, err } // use a time of 1, 64MB of ram, and all of the cores. keyData := argon2.IDKey(password, pathSalt, 1, uint32(64*memory.MiB/memory.KiB), argon2Threads, 32) if len(keyData) != len(storj.Key{}) { return nil, errs.New("invalid output from argon2id") } var key storj.Key copy(key[:], keyData) return &key, nil }