openpgp: make the deprecation message more explicit

The package is unmaintained, unsafe at any speed, and does not receive
security fixes. Document that, and point at the ProtonMail fork for
those that _must_ still use OpenPGP.

Change-Id: Ia602eaaf9e08bd25389400ebe7f346b60bdb9d99
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/794200
Auto-Submit: Roland Shoemaker <roland@golang.org>
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>

openpgp/armor/armor.go

@@ -5,11 +5,12 @@
 // Package armor implements OpenPGP ASCII Armor, see RFC 4880. OpenPGP Armor is
 // very similar to PEM except that it has an additional CRC checksum.
 //
-// Deprecated: this package is unmaintained except for security fixes. New
-// applications should consider a more focused, modern alternative to OpenPGP
-// for their specific task. If you are required to interoperate with OpenPGP
-// systems and need a maintained package, consider a community fork.
-// See https://golang.org/issue/44226.
+// Deprecated: this package is unsafe by design, and has numerous known security
+// issues. It is not maintained, and should not be used. New applications should
+// consider a more focused, modern alternative to OpenPGP for their specific
+// task. If you are required to interoperate with OpenPGP systems and need a
+// maintained package, consider github.com/ProtonMail/go-crypto/openpgp, which
+// is a maintained fork that aims to be a drop-in replacement for this package.
 package armor
 
 import (

openpgp/clearsign/clearsign.go

@@ -8,11 +8,12 @@
 // Clearsigned messages are cryptographically signed, but the contents of the
 // message are kept in plaintext so that it can be read without special tools.
 //
-// Deprecated: this package is unmaintained except for security fixes. New
-// applications should consider a more focused, modern alternative to OpenPGP
-// for their specific task. If you are required to interoperate with OpenPGP
-// systems and need a maintained package, consider a community fork.
-// See https://golang.org/issue/44226.
+// Deprecated: this package is unsafe by design, and has numerous known security
+// issues. It is not maintained, and should not be used. New applications should
+// consider a more focused, modern alternative to OpenPGP for their specific
+// task. If you are required to interoperate with OpenPGP systems and need a
+// maintained package, consider github.com/ProtonMail/go-crypto/openpgp, which
+// is a maintained fork that aims to be a drop-in replacement for this package.
 package clearsign
 
 import (

openpgp/errors/errors.go

@@ -4,11 +4,12 @@
 
 // Package errors contains common error types for the OpenPGP packages.
 //
-// Deprecated: this package is unmaintained except for security fixes. New
-// applications should consider a more focused, modern alternative to OpenPGP
-// for their specific task. If you are required to interoperate with OpenPGP
-// systems and need a maintained package, consider a community fork.
-// See https://golang.org/issue/44226.
+// Deprecated: this package is unsafe by design, and has numerous known security
+// issues. It is not maintained, and should not be used. New applications should
+// consider a more focused, modern alternative to OpenPGP for their specific
+// task. If you are required to interoperate with OpenPGP systems and need a
+// maintained package, consider github.com/ProtonMail/go-crypto/openpgp, which
+// is a maintained fork that aims to be a drop-in replacement for this package.
 package errors
 
 import (

openpgp/packet/packet.go

@@ -5,11 +5,12 @@
 // Package packet implements parsing and serialization of OpenPGP packets, as
 // specified in RFC 4880.
 //
-// Deprecated: this package is unmaintained except for security fixes. New
-// applications should consider a more focused, modern alternative to OpenPGP
-// for their specific task. If you are required to interoperate with OpenPGP
-// systems and need a maintained package, consider a community fork.
-// See https://golang.org/issue/44226.
+// Deprecated: this package is unsafe by design, and has numerous known security
+// issues. It is not maintained, and should not be used. New applications should
+// consider a more focused, modern alternative to OpenPGP for their specific
+// task. If you are required to interoperate with OpenPGP systems and need a
+// maintained package, consider github.com/ProtonMail/go-crypto/openpgp, which
+// is a maintained fork that aims to be a drop-in replacement for this package.
 package packet
 
 import (

openpgp/read.go

@@ -4,11 +4,12 @@
 
 // Package openpgp implements high level operations on OpenPGP messages.
 //
-// Deprecated: this package is unmaintained except for security fixes. New
-// applications should consider a more focused, modern alternative to OpenPGP
-// for their specific task. If you are required to interoperate with OpenPGP
-// systems and need a maintained package, consider a community fork.
-// See https://golang.org/issue/44226.
+// Deprecated: this package is unsafe by design, and has numerous known security
+// issues. It is not maintained, and should not be used. New applications should
+// consider a more focused, modern alternative to OpenPGP for their specific
+// task. If you are required to interoperate with OpenPGP systems and need a
+// maintained package, consider github.com/ProtonMail/go-crypto/openpgp, which
+// is a maintained fork that aims to be a drop-in replacement for this package.
 package openpgp
 
 import (

openpgp/s2k/s2k.go

@@ -5,11 +5,12 @@
 // Package s2k implements the various OpenPGP string-to-key transforms as
 // specified in RFC 4800 section 3.7.1.
 //
-// Deprecated: this package is unmaintained except for security fixes. New
-// applications should consider a more focused, modern alternative to OpenPGP
-// for their specific task. If you are required to interoperate with OpenPGP
-// systems and need a maintained package, consider a community fork.
-// See https://golang.org/issue/44226.
+// Deprecated: this package is unsafe by design, and has numerous known security
+// issues. It is not maintained, and should not be used. New applications should
+// consider a more focused, modern alternative to OpenPGP for their specific
+// task. If you are required to interoperate with OpenPGP systems and need a
+// maintained package, consider github.com/ProtonMail/go-crypto/openpgp, which
+// is a maintained fork that aims to be a drop-in replacement for this package.
 package s2k
 
 import (