crypto: Correct s2k type constants. They are 0,1,3 according to both the RFC: http://tools.ietf.org/html/rfc4880#section-3.7
And according to the gpg implementation: http://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git&a=search&h=refs%2Fheads%2FSTABLE-BRANCH-2-0&st=grep&s=s2kmode

R=agl
CC=evn, golang-dev
https://golang.org/cl/11355046

openpgp/s2k/s2k.go

diff --git a/openpgp/s2k/s2k.go b/openpgp/s2k/s2k.go
index c8b9bbd..c466a8d 100644
--- a/openpgp/s2k/s2k.go
+++ b/openpgp/s2k/s2k.go
@@ -97,12 +97,12 @@
 	}
 
 	switch buf[0] {
-	case 1:
+	case 0:
 		f := func(out, in []byte) {
 			Simple(out, h, in)
 		}
 		return f, nil
-	case 2:
+	case 1:
 		_, err = io.ReadFull(r, buf[:8])
 		if err != nil {
 			return

openpgp/s2k/s2k_test.go

diff --git a/openpgp/s2k/s2k_test.go b/openpgp/s2k/s2k_test.go
index 3a094a1..4898828 100644
--- a/openpgp/s2k/s2k_test.go
+++ b/openpgp/s2k/s2k_test.go
@@ -66,9 +66,9 @@
 	spec, in, out string
 }{
 	/* Simple with SHA1 */
-	{"0102", "hello", "aaf4c61d"},
+	{"0002", "hello", "aaf4c61d"},
 	/* Salted with SHA1 */
-	{"02020102030405060708", "hello", "f4f7d67e"},
+	{"01020102030405060708", "hello", "f4f7d67e"},
 	/* Iterated with SHA1 */
 	{"03020102030405060708f1", "hello", "f2a57b7c"},
 }