Implement GPG api (#710)

* Implement GPG API

* Better handle error

* Apply review recommendation + simplify database operations

* Remove useless comments

4 files changed, 373 insertions, 0 deletions

diff --git a/models/error.go b/models/error.go
index 472c8c9426..62529f83fa 100644
--- a/models/error.go
+++ b/models/error.go
@@ -245,6 +245,54 @@ func (err ErrKeyNameAlreadyUsed) Error() string {
 	return fmt.Sprintf("public key already exists [owner_id: %d, name: %s]", err.OwnerID, err.Name)
 }
 
+// ErrGPGKeyNotExist represents a "GPGKeyNotExist" kind of error.
+type ErrGPGKeyNotExist struct {
+	ID int64
+}
+
+// IsErrGPGKeyNotExist checks if an error is a ErrGPGKeyNotExist.
+func IsErrGPGKeyNotExist(err error) bool {
+	_, ok := err.(ErrGPGKeyNotExist)
+	return ok
+}
+
+func (err ErrGPGKeyNotExist) Error() string {
+	return fmt.Sprintf("public gpg key does not exist [id: %d]", err.ID)
+}
+
+// ErrGPGKeyIDAlreadyUsed represents a "GPGKeyIDAlreadyUsed" kind of error.
+type ErrGPGKeyIDAlreadyUsed struct {
+	KeyID string
+}
+
+// IsErrGPGKeyIDAlreadyUsed checks if an error is a ErrKeyNameAlreadyUsed.
+func IsErrGPGKeyIDAlreadyUsed(err error) bool {
+	_, ok := err.(ErrGPGKeyIDAlreadyUsed)
+	return ok
+}
+
+func (err ErrGPGKeyIDAlreadyUsed) Error() string {
+	return fmt.Sprintf("public key already exists [key_id: %s]", err.KeyID)
+}
+
+// ErrGPGKeyAccessDenied represents a "GPGKeyAccessDenied" kind of Error.
+type ErrGPGKeyAccessDenied struct {
+	UserID int64
+	KeyID  int64
+}
+
+// IsErrGPGKeyAccessDenied checks if an error is a ErrGPGKeyAccessDenied.
+func IsErrGPGKeyAccessDenied(err error) bool {
+	_, ok := err.(ErrGPGKeyAccessDenied)
+	return ok
+}
+
+// Error pretty-prints an error of type ErrGPGKeyAccessDenied.
+func (err ErrGPGKeyAccessDenied) Error() string {
+	return fmt.Sprintf("user does not have access to the key [user_id: %d, key_id: %d]",
+		err.UserID, err.KeyID)
+}
+
 // ErrKeyAccessDenied represents a "KeyAccessDenied" kind of error.
 type ErrKeyAccessDenied struct {
 	UserID int64
diff --git a/models/gpg_key.go b/models/gpg_key.go
new file mode 100644
index 0000000000..9ca9a1baf0
--- /dev/null
+++ b/models/gpg_key.go
@@ -0,0 +1,276 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+import (
+	"bytes"
+	"encoding/base64"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/go-xorm/xorm"
+	"golang.org/x/crypto/openpgp"
+	"golang.org/x/crypto/openpgp/packet"
+)
+
+// GPGKey represents a GPG key.
+type GPGKey struct {
+	ID                int64     `xorm:"pk autoincr"`
+	OwnerID           int64     `xorm:"INDEX NOT NULL"`
+	KeyID             string    `xorm:"INDEX TEXT NOT NULL"`
+	PrimaryKeyID      string    `xorm:"TEXT"`
+	Content           string    `xorm:"TEXT NOT NULL"`
+	Created           time.Time `xorm:"-"`
+	CreatedUnix       int64
+	Expired           time.Time `xorm:"-"`
+	ExpiredUnix       int64
+	Added             time.Time `xorm:"-"`
+	AddedUnix         int64
+	SubsKey           []*GPGKey `xorm:"-"`
+	Emails            []*EmailAddress
+	CanSign           bool
+	CanEncryptComms   bool
+	CanEncryptStorage bool
+	CanCertify        bool
+}
+
+// BeforeInsert will be invoked by XORM before inserting a record
+func (key *GPGKey) BeforeInsert() {
+	key.AddedUnix = time.Now().Unix()
+	key.ExpiredUnix = key.Expired.Unix()
+	key.CreatedUnix = key.Created.Unix()
+}
+
+// AfterSet is invoked from XORM after setting the value of a field of this object.
+func (key *GPGKey) AfterSet(colName string, _ xorm.Cell) {
+	switch colName {
+	case "key_id":
+		x.Where("primary_key_id=?", key.KeyID).Find(&key.SubsKey)
+	case "added_unix":
+		key.Added = time.Unix(key.AddedUnix, 0).Local()
+	case "expired_unix":
+		key.Expired = time.Unix(key.ExpiredUnix, 0).Local()
+	case "created_unix":
+		key.Created = time.Unix(key.CreatedUnix, 0).Local()
+	}
+}
+
+// ListGPGKeys returns a list of public keys belongs to given user.
+func ListGPGKeys(uid int64) ([]*GPGKey, error) {
+	keys := make([]*GPGKey, 0, 5)
+	return keys, x.Where("owner_id=? AND primary_key_id=''", uid).Find(&keys)
+}
+
+// GetGPGKeyByID returns public key by given ID.
+func GetGPGKeyByID(keyID int64) (*GPGKey, error) {
+	key := new(GPGKey)
+	has, err := x.Id(keyID).Get(key)
+	if err != nil {
+		return nil, err
+	} else if !has {
+		return nil, ErrGPGKeyNotExist{keyID}
+	}
+	return key, nil
+}
+
+// checkArmoredGPGKeyString checks if the given key string is a valid GPG armored key.
+// The function returns the actual public key on success
+func checkArmoredGPGKeyString(content string) (*openpgp.Entity, error) {
+	list, err := openpgp.ReadArmoredKeyRing(strings.NewReader(content))
+	if err != nil {
+		return nil, err
+	}
+	return list[0], nil
+}
+
+//addGPGKey add key and subkeys to database
+func addGPGKey(e Engine, key *GPGKey) (err error) {
+	// Save GPG primary key.
+	if _, err = e.Insert(key); err != nil {
+		return err
+	}
+	// Save GPG subs key.
+	for _, subkey := range key.SubsKey {
+		if err := addGPGKey(e, subkey); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// AddGPGKey adds new public key to database.
+func AddGPGKey(ownerID int64, content string) (*GPGKey, error) {
+	ekey, err := checkArmoredGPGKeyString(content)
+	if err != nil {
+		return nil, err
+	}
+
+	// Key ID cannot be duplicated.
+	has, err := x.Where("key_id=?", ekey.PrimaryKey.KeyIdString()).
+		Get(new(GPGKey))
+	if err != nil {
+		return nil, err
+	} else if has {
+		return nil, ErrGPGKeyIDAlreadyUsed{ekey.PrimaryKey.KeyIdString()}
+	}
+
+	//Get DB session
+	sess := x.NewSession()
+	defer sessionRelease(sess)
+	if err = sess.Begin(); err != nil {
+		return nil, err
+	}
+
+	key, err := parseGPGKey(ownerID, ekey)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = addGPGKey(sess, key); err != nil {
+		return nil, err
+	}
+
+	return key, sess.Commit()
+}
+
+//base64EncPubKey encode public kay content to base 64
+func base64EncPubKey(pubkey *packet.PublicKey) (string, error) {
+	var w bytes.Buffer
+	err := pubkey.Serialize(&w)
+	if err != nil {
+		return "", err
+	}
+	return base64.StdEncoding.EncodeToString(w.Bytes()), nil
+}
+
+//parseSubGPGKey parse a sub Key
+func parseSubGPGKey(ownerID int64, primaryID string, pubkey *packet.PublicKey, expiry time.Time) (*GPGKey, error) {
+	content, err := base64EncPubKey(pubkey)
+	if err != nil {
+		return nil, err
+	}
+	return &GPGKey{
+		OwnerID:           ownerID,
+		KeyID:             pubkey.KeyIdString(),
+		PrimaryKeyID:      primaryID,
+		Content:           content,
+		Created:           pubkey.CreationTime,
+		Expired:           expiry,
+		CanSign:           pubkey.CanSign(),
+		CanEncryptComms:   pubkey.PubKeyAlgo.CanEncrypt(),
+		CanEncryptStorage: pubkey.PubKeyAlgo.CanEncrypt(),
+		CanCertify:        pubkey.PubKeyAlgo.CanSign(),
+	}, nil
+}
+
+//parseGPGKey parse a PrimaryKey entity (primary key + subs keys + self-signature)
+func parseGPGKey(ownerID int64, e *openpgp.Entity) (*GPGKey, error) {
+	pubkey := e.PrimaryKey
+
+	//Extract self-sign for expire date based on : https://github.com/golang/crypto/blob/master/openpgp/keys.go#L165
+	var selfSig *packet.Signature
+	for _, ident := range e.Identities {
+		if selfSig == nil {
+			selfSig = ident.SelfSignature
+		} else if ident.SelfSignature.IsPrimaryId != nil && *ident.SelfSignature.IsPrimaryId {
+			selfSig = ident.SelfSignature
+			break
+		}
+	}
+	expiry := time.Time{}
+	if selfSig.KeyLifetimeSecs != nil {
+		expiry = selfSig.CreationTime.Add(time.Duration(*selfSig.KeyLifetimeSecs) * time.Second)
+	}
+
+	//Parse Subkeys
+	subkeys := make([]*GPGKey, len(e.Subkeys))
+	for i, k := range e.Subkeys {
+		subs, err := parseSubGPGKey(ownerID, pubkey.KeyIdString(), k.PublicKey, expiry)
+		if err != nil {
+			return nil, err
+		}
+		subkeys[i] = subs
+	}
+
+	//Check emails
+	userEmails, err := GetEmailAddresses(ownerID)
+	if err != nil {
+		return nil, err
+	}
+	emails := make([]*EmailAddress, len(e.Identities))
+	n := 0
+	for _, ident := range e.Identities {
+
+		for _, e := range userEmails {
+			if e.Email == ident.UserId.Email && e.IsActivated {
+				emails[n] = e
+				break
+			}
+		}
+		if emails[n] == nil {
+			return nil, fmt.Errorf("Failed to found email or is not confirmed : %s", ident.UserId.Email)
+		}
+		n++
+	}
+	content, err := base64EncPubKey(pubkey)
+	if err != nil {
+		return nil, err
+	}
+	return &GPGKey{
+		OwnerID:           ownerID,
+		KeyID:             pubkey.KeyIdString(),
+		PrimaryKeyID:      "",
+		Content:           content,
+		Created:           pubkey.CreationTime,
+		Expired:           expiry,
+		Emails:            emails,
+		SubsKey:           subkeys,
+		CanSign:           pubkey.CanSign(),
+		CanEncryptComms:   pubkey.PubKeyAlgo.CanEncrypt(),
+		CanEncryptStorage: pubkey.PubKeyAlgo.CanEncrypt(),
+		CanCertify:        pubkey.PubKeyAlgo.CanSign(),
+	}, nil
+}
+
+// deleteGPGKey does the actual key deletion
+func deleteGPGKey(e *xorm.Session, keyID string) (int64, error) {
+	if keyID == "" {
+		return 0, fmt.Errorf("empty KeyId forbidden") //Should never happen but just to be sure
+	}
+	return e.Where("key_id=?", keyID).Or("primary_key_id=?", keyID).Delete(new(GPGKey))
+}
+
+// DeleteGPGKey deletes GPG key information in database.
+func DeleteGPGKey(doer *User, id int64) (err error) {
+	key, err := GetGPGKeyByID(id)
+	if err != nil {
+		if IsErrGPGKeyNotExist(err) {
+			return nil
+		}
+		return fmt.Errorf("GetPublicKeyByID: %v", err)
+	}
+
+	// Check if user has access to delete this key.
+	if !doer.IsAdmin && doer.ID != key.OwnerID {
+		return ErrGPGKeyAccessDenied{doer.ID, key.ID}
+	}
+
+	sess := x.NewSession()
+	defer sessionRelease(sess)
+	if err = sess.Begin(); err != nil {
+		return err
+	}
+
+	if _, err = deleteGPGKey(sess, key.KeyID); err != nil {
+		return err
+	}
+
+	if err = sess.Commit(); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/models/gpg_key_test.go b/models/gpg_key_test.go
new file mode 100644
index 0000000000..1ef5838e31
--- /dev/null
+++ b/models/gpg_key_test.go
@@ -0,0 +1,48 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCheckArmoredGPGKeyString(t *testing.T) {
+	testGPGArmor := `-----BEGIN PGP PUBLIC KEY BLOCK-----
+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+=i9b7
+-----END PGP PUBLIC KEY BLOCK-----`
+
+	key, err := checkArmoredGPGKeyString(testGPGArmor)
+	assert.Nil(t, err, "Could not parse a valid GPG armored key", key)
+	//TODO verify value of key
+}
diff --git a/models/models.go b/models/models.go
index 5b9020bac6..bba4446db0 100644
--- a/models/models.go
+++ b/models/models.go
@@ -111,6 +111,7 @@ func init() {
 		new(IssueUser),
 		new(LFSMetaObject),
 		new(TwoFactor),
+		new(GPGKey),
 		new(RepoUnit),
 		new(RepoRedirect),
 		new(ExternalLoginUser),