feat: add gpg integration

This commit adds gpg system integration. This is done through two new
packages: gpgbin, which handles the system calls and parsing; and gpg
which is mostly a copy of emersion/go-pgpmail with modifications to
interface with package gpgbin. gpg includes tests for many cases, and
by it's nature also tests package gpgbin. I separated these in case an
external dependency is ever used for the gpg sys-calls/parsing (IE we
mirror how go-pgpmail+openpgp currently are dependencies)

Two new config options are introduced:
* pgp-provider. If it is not explicitly set to "gpg", aerc will default to
it's internal pgp provider
* pgp-key-id: (Optionally) specify a key by short or long keyId

Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
Acked-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>

1 files changed, 122 insertions, 0 deletions

diff --git a/lib/crypto/gpg/writer_test.go b/lib/crypto/gpg/writer_test.go
new file mode 100644
index 0000000..0f9ab10
--- /dev/null
+++ b/lib/crypto/gpg/writer_test.go
@@ -0,0 +1,122 @@
+package gpg
+
+import (
+	"bytes"
+	"io"
+	"strings"
+	"testing"
+
+	"git.sr.ht/~rjarry/aerc/lib/crypto/gpg/gpgbin"
+	"git.sr.ht/~rjarry/aerc/models"
+	"github.com/emersion/go-message/textproto"
+)
+
+func init() {
+	forceBoundary = "foo"
+}
+
+func TestEncrypt(t *testing.T) {
+	importPublicKey()
+	importSecretKey()
+	var h textproto.Header
+	h.Set("From", "John Doe <john.doe@example.org>")
+	h.Set("To", "John Doe <john.doe@example.org>")
+
+	var encryptedHeader textproto.Header
+	encryptedHeader.Set("Content-Type", "text/plain")
+
+	var encryptedBody = "This is an encrypted message!\r\n"
+
+	to := []string{"john.doe@example.org"}
+	from := "john.doe@example.org"
+
+	var buf bytes.Buffer
+	cleartext, err := Encrypt(&buf, h, to, from)
+	if err != nil {
+		t.Fatalf("Encrypt() = %v", err)
+	}
+
+	if err = textproto.WriteHeader(cleartext, encryptedHeader); err != nil {
+		t.Fatalf("textproto.WriteHeader() = %v", err)
+	}
+	if _, err = io.WriteString(cleartext, encryptedBody); err != nil {
+		t.Fatalf("io.WriteString() = %v", err)
+	}
+	if err = cleartext.Close(); err != nil {
+		t.Fatalf("ciphertext.Close() = %v", err)
+	}
+
+	md, err := gpgbin.Decrypt(&buf)
+	if err != nil {
+		t.Errorf("Encrypt error: could not decrypt test encryption")
+	}
+	var body bytes.Buffer
+	io.Copy(&body, md.Body)
+	if s := body.String(); s != wantEncrypted {
+		t.Errorf("Encrypt() = \n%v\n but want \n%v", s, wantEncrypted)
+	}
+
+	t.Cleanup(CleanUp)
+}
+
+func TestSign(t *testing.T) {
+	importPublicKey()
+	importSecretKey()
+	var h textproto.Header
+	h.Set("From", "John Doe <john.doe@example.org>")
+	h.Set("To", "John Doe <john.doe@example.org>")
+
+	var signedHeader textproto.Header
+	signedHeader.Set("Content-Type", "text/plain")
+
+	var signedBody = "This is a signed message!\r\n"
+
+	var buf bytes.Buffer
+	cleartext, err := Sign(&buf, h, "john.doe@example.org")
+	if err != nil {
+		t.Fatalf("Encrypt() = %v", err)
+	}
+
+	if err = textproto.WriteHeader(cleartext, signedHeader); err != nil {
+		t.Fatalf("textproto.WriteHeader() = %v", err)
+	}
+	if _, err = io.WriteString(cleartext, signedBody); err != nil {
+		t.Fatalf("io.WriteString() = %v", err)
+	}
+
+	if err = cleartext.Close(); err != nil {
+		t.Fatalf("ciphertext.Close() = %v", err)
+	}
+
+	parts := strings.Split(buf.String(), "\r\n--foo\r\n")
+	msg := strings.NewReader(parts[1])
+	sig := strings.NewReader(parts[2])
+	md, err := gpgbin.Verify(msg, sig)
+	if err != nil {
+		t.Fatalf("gpg.Verify() = %v", err)
+	}
+
+	deepEqual(t, md, &wantSigned)
+}
+
+var wantEncrypted = toCRLF(`Content-Type: text/plain
+
+This is an encrypted message!
+`)
+
+var wantSignedBody = toCRLF(`Content-Type: text/plain
+
+This is a signed message!
+`)
+
+var wantSigned = models.MessageDetails{
+	IsEncrypted:        false,
+	IsSigned:           true,
+	SignedBy:           "John Doe (This is a test key) <john.doe@example.org>",
+	SignedByKeyId:      3490876580878068068,
+	SignatureError:     "",
+	DecryptedWith:      "",
+	DecryptedWithKeyId: 0,
+	Body:               strings.NewReader(wantSignedBody),
+	Micalg:             "pgp-sha256",
+}