diff options
| -rw-r--r-- | challenge/c28.go | 9 | ||||
| -rw-r--r-- | lib/sha1.go | 30 |
2 files changed, 29 insertions, 10 deletions
diff --git a/challenge/c28.go b/challenge/c28.go index 7a763d5..a54be26 100644 --- a/challenge/c28.go +++ b/challenge/c28.go @@ -35,11 +35,14 @@ I'm pushin' away, I'm pushin' away Yeah I'm pushin' away, pushin' away`) sec := lib.StrToBytes("Milk Records") + // Init SHA1 + sha1 := lib.Sha1{} + // Generate SHA1 MAC. - mac := lib.Sha1Mac(sec, msg) + mac := sha1.Mac(sec, msg) // Verify. - if lib.Sha1MacVerify(sec, msg, mac) != true { + if sha1.MacVerify(sec, msg, mac) != true { fmt.Printf("Error: Sha1Mac verification failed!\n") return } @@ -48,7 +51,7 @@ Yeah I'm pushin' away, pushin' away`) msg[42] = byte(42) // Verify that SHA1 MAC fails - if lib.Sha1MacVerify(sec, msg, mac) != false { + if sha1.MacVerify(sec, msg, mac) != false { fmt.Printf("Error: Sha1Mac verification success!\n") return } diff --git a/lib/sha1.go b/lib/sha1.go index bfe87b1..34f5f37 100644 --- a/lib/sha1.go +++ b/lib/sha1.go @@ -6,8 +6,12 @@ package lib // SHA-1 implementation. // Reference https://csrc.nist.gov/publications/detail/fips/180/4/final +type Sha1 struct { + hvs []uint32 +} + // Initial hash value. -var sha1IHashValue []uint32 = []uint32{ +var sha1IHashValues []uint32 = []uint32{ 0x67452301, 0xefcdab89, 0x98badcfe, @@ -149,7 +153,19 @@ func sha1MessageSchedule(mb []uint32) []uint32 { return w } -func Sha1(m []byte) []byte { +func (s *Sha1) Init(hvs []uint32) { + // Set Initial Hash Values. + h := make([]uint32, 5) + if len(hvs) == 5 { + copy(h, hvs) + s.hvs = h + } else { + copy(h, sha1IHashValues) + s.hvs = h + } +} + +func (s *Sha1) Hash(m []byte) []byte { // Pad message. pm := sha1Pad(m) @@ -158,7 +174,7 @@ func Sha1(m []byte) []byte { // Initialize hash values. h := make([]uint32, 5) - copy(h, sha1IHashValue) // Initial hash values. + copy(h, s.hvs) // Initial hash values. // Process each message block. for _, mb := range mbs { @@ -208,12 +224,12 @@ func Sha1(m []byte) []byte { return d } -func Sha1Mac(secret, msg []byte) []byte { - return Sha1(append(secret, msg...)) +func (s *Sha1) Mac(secret, msg []byte) []byte { + return s.Hash(append(secret, msg...)) } -func Sha1MacVerify(secret, msg, mac []byte) bool { - if BytesEqual(Sha1(append(secret, msg...)), mac) { +func (s *Sha1) MacVerify(secret, msg, mac []byte) bool { + if BytesEqual(s.Hash(append(secret, msg...)), mac) { return true } return false |