crypto/sha256: provide top-level Sum and Sum224 functions
Makes it easy to ask the simple question, what is the hash of this data?
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10629043
diff --git a/src/pkg/crypto/sha256/sha256.go b/src/pkg/crypto/sha256/sha256.go
index dc0e18f..90e71cd 100644
--- a/src/pkg/crypto/sha256/sha256.go
+++ b/src/pkg/crypto/sha256/sha256.go
@@ -134,9 +134,16 @@
func (d0 *digest) Sum(in []byte) []byte {
// Make a copy of d0 so that caller can keep writing and summing.
d := *d0
+ hash := d.checkSum()
+ if d.is224 {
+ return append(in, hash[:Size224]...)
+ }
+ return append(in, hash[:]...)
+}
- // Padding. Add a 1 bit and 0 bits until 56 bytes mod 64.
+func (d *digest) checkSum() [Size]byte {
len := d.len
+ // Padding. Add a 1 bit and 0 bits until 56 bytes mod 64.
var tmp [64]byte
tmp[0] = 0x80
if len%64 < 56 {
@@ -157,10 +164,8 @@
}
h := d.h[:]
- size := Size
if d.is224 {
h = d.h[:7]
- size = Size224
}
var digest [Size]byte
@@ -171,5 +176,24 @@
digest[i*4+3] = byte(s)
}
- return append(in, digest[:size]...)
+ return digest
+}
+
+// Sum returns the SHA256 checksum of the data.
+func Sum256(data []byte) [Size]byte {
+ var d digest
+ d.Reset()
+ d.Write(data)
+ return d.checkSum()
+}
+
+// Sum224 returns the SHA224 checksum of the data.
+func Sum224(data []byte) (sum224 [Size224]byte) {
+ var d digest
+ d.is224 = true
+ d.Reset()
+ d.Write(data)
+ sum := d.checkSum()
+ copy(sum224[:], sum[:Size224])
+ return
}
diff --git a/src/pkg/crypto/sha256/sha256_test.go b/src/pkg/crypto/sha256/sha256_test.go
index 29bf161..0dc8886 100644
--- a/src/pkg/crypto/sha256/sha256_test.go
+++ b/src/pkg/crypto/sha256/sha256_test.go
@@ -88,6 +88,10 @@
func TestGolden(t *testing.T) {
for i := 0; i < len(golden); i++ {
g := golden[i]
+ s := fmt.Sprintf("%x", Sum256([]byte(g.in)))
+ if s != g.out {
+ t.Fatalf("Sum function: sha256(%s) = %s want %s", g.in, s, g.out)
+ }
c := New()
for j := 0; j < 3; j++ {
if j < 2 {
@@ -106,6 +110,10 @@
}
for i := 0; i < len(golden224); i++ {
g := golden224[i]
+ s := fmt.Sprintf("%x", Sum224([]byte(g.in)))
+ if s != g.out {
+ t.Fatalf("Sum224 function: sha224(%s) = %s want %s", g.in, s, g.out)
+ }
c := New224()
for j := 0; j < 3; j++ {
if j < 2 {
