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, 167 insertions, 0 deletions

diff --git a/lib/crypto/gpg/gpg_test.go b/lib/crypto/gpg/gpg_test.go
new file mode 100644
index 0000000..61c2ec6
--- /dev/null
+++ b/lib/crypto/gpg/gpg_test.go
@@ -0,0 +1,167 @@
+package gpg
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	"os/exec"
+	"strings"
+	"testing"
+
+	"git.sr.ht/~rjarry/aerc/models"
+)
+
+func TestHasGpg(t *testing.T) {
+	gpgmail := new(Mail)
+	hasGpg := gpgmail.Init(new(log.Logger))
+
+	if hasGpg != nil {
+		t.Errorf("System does not have GPG")
+	}
+}
+
+func CleanUp() {
+	cmd := exec.Command("gpg", "--batch", "--yes", "--delete-secret-and-public-keys", testKeyId)
+	err := cmd.Run()
+	if err != nil {
+		fmt.Println("Test cleanup failed: you may need to delete the test keys from your GPG keyring")
+		return
+	}
+}
+
+func toCRLF(s string) string {
+	return strings.ReplaceAll(s, "\n", "\r\n")
+}
+
+func deepEqual(t *testing.T, r *models.MessageDetails, expect *models.MessageDetails) {
+	var resBuf bytes.Buffer
+	if _, err := io.Copy(&resBuf, r.Body); err != nil {
+		t.Fatalf("io.Copy() = %v", err)
+	}
+
+	var expBuf bytes.Buffer
+	if _, err := io.Copy(&expBuf, expect.Body); err != nil {
+		t.Fatalf("io.Copy() = %v", err)
+	}
+
+	if resBuf.String() != expBuf.String() {
+		t.Errorf("MessagesDetails.Body = \n%v\n but want \n%v", resBuf.String(), expBuf.String())
+	}
+
+	if r.IsEncrypted != expect.IsEncrypted {
+		t.Errorf("IsEncrypted = \n%v\n but want \n%v", r.IsEncrypted, expect.IsEncrypted)
+	}
+	if r.IsSigned != expect.IsSigned {
+		t.Errorf("IsSigned = \n%v\n but want \n%v", r.IsSigned, expect.IsSigned)
+	}
+	if r.SignedBy != expect.SignedBy {
+		t.Errorf("SignedBy = \n%v\n but want \n%v", r.SignedBy, expect.SignedBy)
+	}
+	if r.SignedByKeyId != expect.SignedByKeyId {
+		t.Errorf("SignedByKeyId = \n%v\n but want \n%v", r.SignedByKeyId, expect.SignedByKeyId)
+	}
+	if r.SignatureError != expect.SignatureError {
+		t.Errorf("SignatureError = \n%v\n but want \n%v", r.SignatureError, expect.SignatureError)
+	}
+	if r.DecryptedWith != expect.DecryptedWith {
+		t.Errorf("DecryptedWith = \n%v\n but want \n%v", r.DecryptedWith, expect.DecryptedWith)
+	}
+	if r.DecryptedWithKeyId != expect.DecryptedWithKeyId {
+		t.Errorf("DecryptedWithKeyId = \n%v\n but want \n%v", r.DecryptedWithKeyId, expect.DecryptedWithKeyId)
+	}
+}
+
+const testKeyId = `B1A8669354153B799F2217BF307215C13DF7A964`
+
+const testPrivateKeyArmored = `-----BEGIN PGP PRIVATE KEY BLOCK-----
+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+=gemU
+-----END PGP PRIVATE KEY BLOCK-----
+`
+
+const testPublicKeyArmored = `-----BEGIN PGP PUBLIC KEY BLOCK-----
+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ZjQT
+-----END PGP PUBLIC KEY BLOCK-----
+`