crypto/rsa: add PKCS#1 v1.5 signature support.

crypto/rsa: add PKCS#1 v1.5 signature support.

[rsc, 2009-11-18 02:03:16]

LGTM

just a few ways to cut the verbosity

http://codereview.appspot.com/156051/diff/5/6
File src/pkg/crypto/rsa/pkcs1v15.go (right):

http://codereview.appspot.com/156051/diff/5/6#newcode146
src/pkg/crypto/rsa/pkcs1v15.go:146: HashSHA1	PKCS1v15Hash	= iota;
HashSHA1;
HashSHA256;
etc

http://codereview.appspot.com/156051/diff/5/6#newcode227
src/pkg/crypto/rsa/pkcs1v15.go:227: firstByteIsZero :=
subtle.ConstantTimeByteEq(em[0], 0);
s/firstByteIsZero/ok/

http://codereview.appspot.com/156051/diff/5/6#newcode228
src/pkg/crypto/rsa/pkcs1v15.go:228: secondByteIsOne :=
subtle.ConstantTimeByteEq(em[1], 1);
s/secondByteIsOne :=/ok &=/
etc.

http://codereview.appspot.com/156051/diff/5/6#newcode233
src/pkg/crypto/rsa/pkcs1v15.go:233: psCorrect := 1;
delete

http://codereview.appspot.com/156051/diff/5/6#newcode235
src/pkg/crypto/rsa/pkcs1v15.go:235: psCorrect &=
subtle.ConstantTimeByteEq(em[i], 0xff)
ok &=

http://codereview.appspot.com/156051/diff/5/6#newcode238
src/pkg/crypto/rsa/pkcs1v15.go:238: if
firstByteIsZero&secondByteIsOne&hashCorrect&prefixCorrect&finalZeroCorrect&psCorrect
!= 1 {
if ok != 1 {

[agl1, 2009-11-18 02:21:14]

http://codereview.appspot.com/156051/diff/5/6
File src/pkg/crypto/rsa/pkcs1v15.go (right):

http://codereview.appspot.com/156051/diff/5/6#newcode146
src/pkg/crypto/rsa/pkcs1v15.go:146: HashSHA1	PKCS1v15Hash	= iota;
On 2009/11/18 02:03:16, rsc wrote:
> HashSHA1;
> HashSHA256;
> etc
> 

Done.

http://codereview.appspot.com/156051/diff/5/6#newcode227
src/pkg/crypto/rsa/pkcs1v15.go:227: firstByteIsZero :=
subtle.ConstantTimeByteEq(em[0], 0);
On 2009/11/18 02:03:16, rsc wrote:
> s/firstByteIsZero/ok/
> 

Done.

http://codereview.appspot.com/156051/diff/5/6#newcode228
src/pkg/crypto/rsa/pkcs1v15.go:228: secondByteIsOne :=
subtle.ConstantTimeByteEq(em[1], 1);
On 2009/11/18 02:03:16, rsc wrote:
> s/secondByteIsOne :=/ok &=/
> etc.
> 

Done.

http://codereview.appspot.com/156051/diff/5/6#newcode233
src/pkg/crypto/rsa/pkcs1v15.go:233: psCorrect := 1;
On 2009/11/18 02:03:16, rsc wrote:
> delete
> 

Done.

http://codereview.appspot.com/156051/diff/5/6#newcode235
src/pkg/crypto/rsa/pkcs1v15.go:235: psCorrect &=
subtle.ConstantTimeByteEq(em[i], 0xff)
On 2009/11/18 02:03:16, rsc wrote:
> ok &=
> 

Done.

http://codereview.appspot.com/156051/diff/5/6#newcode238
src/pkg/crypto/rsa/pkcs1v15.go:238: if
firstByteIsZero&secondByteIsOne&hashCorrect&prefixCorrect&finalZeroCorrect&psCorrect
!= 1 {
On 2009/11/18 02:03:16, rsc wrote:
> if ok != 1 {
> 

Done.

[agl1, 2009-11-18 02:21:49]

*** Submitted as http://code.google.com/p/go/source/detail?r=d1b75410b793 ***

crypto/rsa: add PKCS#1 v1.5 signature support.

R=rsc
CC=golang-dev
http://codereview.appspot.com/156051