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path: root/src/pkg/crypto/block/eax.go
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Diffstat (limited to 'src/pkg/crypto/block/eax.go')
-rw-r--r--src/pkg/crypto/block/eax.go162
1 files changed, 81 insertions, 81 deletions
diff --git a/src/pkg/crypto/block/eax.go b/src/pkg/crypto/block/eax.go
index 07919e4ae..fcd5fe20f 100644
--- a/src/pkg/crypto/block/eax.go
+++ b/src/pkg/crypto/block/eax.go
@@ -15,18 +15,18 @@
package block
import (
- "fmt";
- "hash";
- "io";
- "os";
+ "fmt"
+ "hash"
+ "io"
+ "os"
)
// An EAXTagError is returned when the message has failed to authenticate,
// because the tag at the end of the message stream (Read) does not match
// the tag computed from the message itself (Computed).
type EAXTagError struct {
- Read []byte;
- Computed []byte;
+ Read []byte
+ Computed []byte
}
func (e *EAXTagError) String() string {
@@ -34,39 +34,39 @@ func (e *EAXTagError) String() string {
}
func setupEAX(c Cipher, iv, hdr []byte, tagBytes int) (ctrIV, tag []byte, cmac hash.Hash) {
- n := len(iv);
+ n := len(iv)
if n != c.BlockSize() {
panicln("crypto/block: EAX: iv length", n, "!=", c.BlockSize())
}
- buf := make([]byte, n); // zeroed
+ buf := make([]byte, n) // zeroed
// tag = CMAC(0 + iv) ^ CMAC(1 + hdr) ^ CMAC(2 + data)
- cmac = NewCMAC(c);
- cmac.Write(buf); // 0
- cmac.Write(iv);
- sum := cmac.Sum();
- ctrIV = copy(sum);
- tag = copy(sum[0:tagBytes]);
-
- cmac.Reset();
- buf[n-1] = 1;
- cmac.Write(buf); // 1
- cmac.Write(hdr);
- sum = cmac.Sum();
+ cmac = NewCMAC(c)
+ cmac.Write(buf) // 0
+ cmac.Write(iv)
+ sum := cmac.Sum()
+ ctrIV = copy(sum)
+ tag = copy(sum[0:tagBytes])
+
+ cmac.Reset()
+ buf[n-1] = 1
+ cmac.Write(buf) // 1
+ cmac.Write(hdr)
+ sum = cmac.Sum()
for i := 0; i < tagBytes; i++ {
tag[i] ^= sum[i]
}
- cmac.Reset();
- buf[n-1] = 2; // 2
- cmac.Write(buf);
+ cmac.Reset()
+ buf[n-1] = 2 // 2
+ cmac.Write(buf)
- return;
+ return
}
func finishEAX(tag []byte, cmac hash.Hash) {
// Finish CMAC #2 and xor into tag.
- sum := cmac.Sum();
+ sum := cmac.Sum()
for i := range tag {
tag[i] ^= sum[i]
}
@@ -75,21 +75,21 @@ func finishEAX(tag []byte, cmac hash.Hash) {
// Writer adapter. Tees writes into both w and cmac.
// Knows that cmac never returns write errors.
type cmacWriter struct {
- w io.Writer;
- cmac hash.Hash;
+ w io.Writer
+ cmac hash.Hash
}
func (cw *cmacWriter) Write(p []byte) (n int, err os.Error) {
- n, err = cw.w.Write(p);
- cw.cmac.Write(p[0:n]);
- return;
+ n, err = cw.w.Write(p)
+ cw.cmac.Write(p[0:n])
+ return
}
// An eaxEncrypter implements the EAX encryption mode.
type eaxEncrypter struct {
- ctr io.Writer; // CTR encrypter
- cw cmacWriter; // CTR's output stream
- tag []byte;
+ ctr io.Writer // CTR encrypter
+ cw cmacWriter // CTR's output stream
+ tag []byte
}
// NewEAXEncrypter creates and returns a new EAX encrypter
@@ -98,15 +98,15 @@ type eaxEncrypter struct {
// the data it receives and writes that data to w.
// The encrypter's Close method writes a final authenticating tag to w.
func NewEAXEncrypter(c Cipher, iv []byte, hdr []byte, tagBytes int, w io.Writer) io.WriteCloser {
- x := new(eaxEncrypter);
+ x := new(eaxEncrypter)
// Create new CTR instance writing to both
// w for encrypted output and cmac for digesting.
- x.cw.w = w;
- var ctrIV []byte;
- ctrIV, x.tag, x.cw.cmac = setupEAX(c, iv, hdr, tagBytes);
- x.ctr = NewCTRWriter(c, ctrIV, &x.cw);
- return x;
+ x.cw.w = w
+ var ctrIV []byte
+ ctrIV, x.tag, x.cw.cmac = setupEAX(c, iv, hdr, tagBytes)
+ x.ctr = NewCTRWriter(c, ctrIV, &x.cw)
+ return x
}
func (x *eaxEncrypter) Write(p []byte) (n int, err os.Error) {
@@ -114,16 +114,16 @@ func (x *eaxEncrypter) Write(p []byte) (n int, err os.Error) {
}
func (x *eaxEncrypter) Close() os.Error {
- x.ctr = nil; // crash if Write is called again
+ x.ctr = nil // crash if Write is called again
// Write tag.
- finishEAX(x.tag, x.cw.cmac);
- n, err := x.cw.w.Write(x.tag);
+ finishEAX(x.tag, x.cw.cmac)
+ n, err := x.cw.w.Write(x.tag)
if n != len(x.tag) && err == nil {
err = io.ErrShortWrite
}
- return err;
+ return err
}
// Reader adapter. Returns data read from r but hangs
@@ -133,10 +133,10 @@ func (x *eaxEncrypter) Close() os.Error {
// and the "tee into digest" functionality could be separated,
// but the latter half is trivial.
type cmacReader struct {
- r io.Reader;
- cmac hash.Hash;
- tag []byte;
- tmp []byte;
+ r io.Reader
+ cmac hash.Hash
+ tag []byte
+ tmp []byte
}
func (cr *cmacReader) Read(p []byte) (n int, err os.Error) {
@@ -147,21 +147,21 @@ func (cr *cmacReader) Read(p []byte) (n int, err os.Error) {
// First, read a tag-sized chunk.
// It's probably not the tag (unless there's no data).
- tag := cr.tag;
+ tag := cr.tag
if len(tag) < cap(tag) {
- nt := len(tag);
- nn, err1 := io.ReadFull(cr.r, tag[nt:cap(tag)]);
- tag = tag[0 : nt+nn];
- cr.tag = tag;
+ nt := len(tag)
+ nn, err1 := io.ReadFull(cr.r, tag[nt:cap(tag)])
+ tag = tag[0 : nt+nn]
+ cr.tag = tag
if err1 != nil {
return 0, err1
}
}
- tagBytes := len(tag);
+ tagBytes := len(tag)
if len(p) > 4*tagBytes {
// If p is big, try to read directly into p to avoid a copy.
- n, err = cr.r.Read(p[tagBytes:]);
+ n, err = cr.r.Read(p[tagBytes:])
if n == 0 {
goto out
}
@@ -173,19 +173,19 @@ func (cr *cmacReader) Read(p []byte) (n int, err os.Error) {
for i := 0; i < tagBytes; i++ {
tag[i] = p[n+i]
}
- goto out;
+ goto out
}
// Otherwise, read into p and then slide data
- n, err = cr.r.Read(p);
+ n, err = cr.r.Read(p)
if n == 0 {
goto out
}
// copy tag+p into p+tmp and then swap tmp, tag
- tmp := cr.tmp;
+ tmp := cr.tmp
for i := n + tagBytes - 1; i >= 0; i-- {
- var c byte;
+ var c byte
if i < tagBytes {
c = tag[i]
} else {
@@ -197,17 +197,17 @@ func (cr *cmacReader) Read(p []byte) (n int, err os.Error) {
tmp[i] = c
}
}
- cr.tmp, cr.tag = tag, tmp;
+ cr.tmp, cr.tag = tag, tmp
out:
- cr.cmac.Write(p[0:n]);
- return;
+ cr.cmac.Write(p[0:n])
+ return
}
type eaxDecrypter struct {
- ctr io.Reader;
- cr cmacReader;
- tag []byte;
+ ctr io.Reader
+ cr cmacReader
+ tag []byte
}
// NewEAXDecrypter creates and returns a new EAX decrypter
@@ -220,34 +220,34 @@ type eaxDecrypter struct {
// assumed to be valid, authenticated data until Read returns
// 0, nil to signal the end of the data.
func NewEAXDecrypter(c Cipher, iv []byte, hdr []byte, tagBytes int, r io.Reader) io.Reader {
- x := new(eaxDecrypter);
+ x := new(eaxDecrypter)
- x.cr.r = r;
- x.cr.tag = make([]byte, 0, tagBytes);
- x.cr.tmp = make([]byte, 0, tagBytes);
- var ctrIV []byte;
- ctrIV, x.tag, x.cr.cmac = setupEAX(c, iv, hdr, tagBytes);
- x.ctr = NewCTRReader(c, ctrIV, &x.cr);
- return x;
+ x.cr.r = r
+ x.cr.tag = make([]byte, 0, tagBytes)
+ x.cr.tmp = make([]byte, 0, tagBytes)
+ var ctrIV []byte
+ ctrIV, x.tag, x.cr.cmac = setupEAX(c, iv, hdr, tagBytes)
+ x.ctr = NewCTRReader(c, ctrIV, &x.cr)
+ return x
}
func (x *eaxDecrypter) checkTag() os.Error {
- x.ctr = nil; // crash if Read is called again
+ x.ctr = nil // crash if Read is called again
- finishEAX(x.tag, x.cr.cmac);
+ finishEAX(x.tag, x.cr.cmac)
if !same(x.tag, x.cr.tag) {
- e := new(EAXTagError);
- e.Computed = copy(x.tag);
- e.Read = copy(x.cr.tag);
- return e;
+ e := new(EAXTagError)
+ e.Computed = copy(x.tag)
+ e.Read = copy(x.cr.tag)
+ return e
}
- return nil;
+ return nil
}
func (x *eaxDecrypter) Read(p []byte) (n int, err os.Error) {
- n, err = x.ctr.Read(p);
+ n, err = x.ctr.Read(p)
if n == 0 && err == nil {
err = x.checkTag()
}
- return n, err;
+ return n, err
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-12 15:39:03 +0000