Disable DSA ssh keys by default (#13056)

* Disable DSA ssh keys by default

OpenSSH has disabled DSA keys since version 7.0

As the docker runs openssh > v7.0 we should just disable
DSA keys by default.

Refers to #11417

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Just disable DSA keys by default

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Appears we need to set the minimum key sizes too

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Appears we need to set the minimum key sizes too

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Remove DSA type

* Fix Tests

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Lauris BH <lauris@nix.lv>

custom/conf/app.example.ini

@@ -375,7 +375,7 @@ STATIC_CACHE_TIME = 6h
 ED25519 = 256
 ECDSA = 256
 RSA = 2048
-DSA = 1024
+DSA = -1 ; set to 1024 to switch on
 
 [database]
 ; Database to use. Either "mysql", "postgres", "mssql" or "sqlite3".

docker/root/etc/templates/sshd_config

@@ -9,8 +9,8 @@ LogLevel INFO
 
 HostKey /data/ssh/ssh_host_ed25519_key
 HostKey /data/ssh/ssh_host_rsa_key
-HostKey /data/ssh/ssh_host_dsa_key
 HostKey /data/ssh/ssh_host_ecdsa_key
+HostKey /data/ssh/ssh_host_dsa_key
 
 AuthorizedKeysFile .ssh/authorized_keys
 

docs/content/doc/advanced/config-cheat-sheet.en-us.md

@@ -258,7 +258,7 @@ Values containing `#` or `;` must be quoted using `` ` `` or `"""`.
 - `SSH_KEYGEN_PATH`: **ssh-keygen**: Path to ssh-keygen, default is 'ssh-keygen' which means the shell is responsible for finding out which one to call.
 - `SSH_BACKUP_AUTHORIZED_KEYS`: **true**: Enable SSH Authorized Key Backup when rewriting all keys, default is true.
 - `SSH_EXPOSE_ANONYMOUS`: **false**: Enable exposure of SSH clone URL to anonymous visitors, default is false.
-- `MINIMUM_KEY_SIZE_CHECK`: **false**: Indicate whether to check minimum key size with corresponding type.
+- `MINIMUM_KEY_SIZE_CHECK`: **true**: Indicate whether to check minimum key size with corresponding type.
 
 - `OFFLINE_MODE`: **false**: Disables use of CDN for static files and Gravatar for profile pictures.
 - `DISABLE_ROUTER_LOG`: **false**: Mute printing of the router log.
@@ -479,7 +479,7 @@ Define allowed algorithms and their minimum key length (use -1 to disable a type
 - `ED25519`: **256**
 - `ECDSA`: **256**
 - `RSA`: **2048**
-- `DSA`: **1024**
+- `DSA`: **-1**: DSA is now disabled by default. Set to **1024** to re-enable but ensure you may need to reconfigure your SSHD provider
 
 ## Webhook (`webhook`)
 

integrations/api_admin_test.go

@@ -24,7 +24,7 @@ func TestAPIAdminCreateAndDeleteSSHKey(t *testing.T) {
 	token := getTokenForLoggedInUser(t, session)
 	urlStr := fmt.Sprintf("/api/v1/admin/users/%s/keys?token=%s", keyOwner.Name, token)
 	req := NewRequestWithValues(t, "POST", urlStr, map[string]string{
-		"key":   "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQDAu7tvIvX6ZHrRXuZNfkR3XLHSsuCK9Zn3X58lxBcQzuo5xZgB6vRwwm/QtJuF+zZPtY5hsQILBLmF+BZ5WpKZp1jBeSjH2G7lxet9kbcH+kIVj0tPFEoyKI9wvWqIwC4prx/WVk2wLTJjzBAhyNxfEq7C9CeiX9pQEbEqJfkKCQ== nocomment\n",
+		"key":   "ssh-rsa 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 nocomment\n",
 		"title": "test-key",
 	})
 	resp := session.MakeRequest(t, req, http.StatusCreated)
@@ -64,7 +64,7 @@ func TestAPIAdminDeleteUnauthorizedKey(t *testing.T) {
 	token := getTokenForLoggedInUser(t, session)
 	urlStr := fmt.Sprintf("/api/v1/admin/users/%s/keys?token=%s", adminUsername, token)
 	req := NewRequestWithValues(t, "POST", urlStr, map[string]string{
-		"key":   "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQDAu7tvIvX6ZHrRXuZNfkR3XLHSsuCK9Zn3X58lxBcQzuo5xZgB6vRwwm/QtJuF+zZPtY5hsQILBLmF+BZ5WpKZp1jBeSjH2G7lxet9kbcH+kIVj0tPFEoyKI9wvWqIwC4prx/WVk2wLTJjzBAhyNxfEq7C9CeiX9pQEbEqJfkKCQ== nocomment\n",
+		"key":   "ssh-rsa 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 nocomment\n",
 		"title": "test-key",
 	})
 	resp := session.MakeRequest(t, req, http.StatusCreated)

integrations/api_keys_test.go

@@ -53,7 +53,7 @@ func TestCreateReadOnlyDeployKey(t *testing.T) {
 	keysURL := fmt.Sprintf("/api/v1/repos/%s/%s/keys?token=%s", repoOwner.Name, repo.Name, token)
 	rawKeyBody := api.CreateKeyOption{
 		Title:    "read-only",
-		Key:      "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQDAu7tvIvX6ZHrRXuZNfkR3XLHSsuCK9Zn3X58lxBcQzuo5xZgB6vRwwm/QtJuF+zZPtY5hsQILBLmF+BZ5WpKZp1jBeSjH2G7lxet9kbcH+kIVj0tPFEoyKI9wvWqIwC4prx/WVk2wLTJjzBAhyNxfEq7C9CeiX9pQEbEqJfkKCQ== nocomment\n",
+		Key:      "ssh-rsa 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 nocomment\n",
 		ReadOnly: true,
 	}
 	req := NewRequestWithJSON(t, "POST", keysURL, rawKeyBody)
@@ -79,7 +79,7 @@ func TestCreateReadWriteDeployKey(t *testing.T) {
 	keysURL := fmt.Sprintf("/api/v1/repos/%s/%s/keys?token=%s", repoOwner.Name, repo.Name, token)
 	rawKeyBody := api.CreateKeyOption{
 		Title: "read-write",
-		Key:   "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDsufOCrDDlT8DLkodnnJtbq7uGflcPae7euTfM+Laq4So+v4WeSV362Rg0O/+Sje1UthrhN6lQkfRkdWIlCRQEXg+LMqr6RhvDfZquE2Xwqv/itlz7LjbdAUdYoO1iH7rMSmYvQh4WEnC/DAacKGbhdGIM/ZBz0z6tHm7bPgbI9ykEKekTmPwQFP1Qebvf5NYOFMWqQ2sCEAI9dBMVLoojsIpV+KADf+BotiIi8yNfTG2rzmzpxBpW9fYjd1Sy1yd4NSUpoPbEJJYJ1TrjiSWlYOVq9Ar8xW1O87i6gBjL/3zN7ANeoYhaAXupdOS6YL22YOK/yC0tJtXwwdh/eSrh",
+		Key:   "ssh-rsa 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 nocomment\n",
 	}
 	req := NewRequestWithJSON(t, "POST", keysURL, rawKeyBody)
 	resp := session.MakeRequest(t, req, http.StatusCreated)
@@ -102,7 +102,7 @@ func TestCreateUserKey(t *testing.T) {
 	token := url.QueryEscape(getTokenForLoggedInUser(t, session))
 	keysURL := fmt.Sprintf("/api/v1/user/keys?token=%s", token)
 	keyType := "ssh-rsa"
-	keyContent := "AAAAB3NzaC1yc2EAAAADAQABAAABAQCyTiPTeHJl6Gs5D1FyHT0qTWpVkAy9+LIKjctQXklrePTvUNVrSpt4r2exFYXNMPeA8V0zCrc3Kzs1SZw3jWkG3i53te9onCp85DqyatxOD2pyZ30/gPn1ZUg40WowlFM8gsUFMZqaH7ax6d8nsBKW7N/cRyqesiOQEV9up3tnKjIB8XMTVvC5X4rBWgywz7AFxSv8mmaTHnUgVW4LgMPwnTWo0pxtiIWbeMLyrEE4hIM74gSwp6CRQYo6xnG3fn4yWkcK2X2mT9adQ241IDdwpENJHcry/T6AJ8dNXduEZ67egnk+rVlQ2HM4LpymAv9DAAFFeaQK0hT+3aMDoumV"
+	keyContent := "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"
 	rawKeyBody := api.CreateKeyOption{
 		Title: "test-key",
 		Key:   keyType + " " + keyContent,

models/ssh_key_test.go

@@ -57,6 +57,8 @@ func Test_SSHParsePublicKey(t *testing.T) {
 }
 
 func Test_CheckPublicKeyString(t *testing.T) {
+	oldValue := setting.SSH.MinimumKeySizeCheck
+	setting.SSH.MinimumKeySizeCheck = false
 	for _, test := range []struct {
 		content string
 	}{
@@ -131,7 +133,7 @@ AAAAC3NzaC1lZDI1NTE5AAAAICV0MGX/W9IvLA4FXpIuUcdDcbj5KX4syHgsTy7soVgf
 		_, err := CheckPublicKeyString(test.content)
 		assert.NoError(t, err)
 	}
-
+	setting.SSH.MinimumKeySizeCheck = oldValue
 	for _, invalidKeys := range []struct {
 		content string
 	}{

modules/setting/setting.go

@@ -122,15 +122,16 @@ var (
 		CreateAuthorizedKeysFile bool           `ini:"SSH_CREATE_AUTHORIZED_KEYS_FILE"`
 		ExposeAnonymous          bool           `ini:"SSH_EXPOSE_ANONYMOUS"`
 	}{
-		Disabled:           false,
-		StartBuiltinServer: false,
-		Domain:             "",
-		Port:               22,
-		ServerCiphers:      []string{"aes128-ctr", "aes192-ctr", "aes256-ctr", "aes128-gcm@openssh.com", "arcfour256", "arcfour128"},
-		ServerKeyExchanges: []string{"diffie-hellman-group1-sha1", "diffie-hellman-group14-sha1", "ecdh-sha2-nistp256", "ecdh-sha2-nistp384", "ecdh-sha2-nistp521", "curve25519-sha256@libssh.org"},
-		ServerMACs:         []string{"hmac-sha2-256-etm@openssh.com", "hmac-sha2-256", "hmac-sha1", "hmac-sha1-96"},
-		KeygenPath:         "ssh-keygen",
-		MinimumKeySizes:    map[string]int{"ed25519": 256, "ecdsa": 256, "rsa": 2048, "dsa": 1024},
+		Disabled:            false,
+		StartBuiltinServer:  false,
+		Domain:              "",
+		Port:                22,
+		ServerCiphers:       []string{"aes128-ctr", "aes192-ctr", "aes256-ctr", "aes128-gcm@openssh.com", "arcfour256", "arcfour128"},
+		ServerKeyExchanges:  []string{"diffie-hellman-group1-sha1", "diffie-hellman-group14-sha1", "ecdh-sha2-nistp256", "ecdh-sha2-nistp384", "ecdh-sha2-nistp521", "curve25519-sha256@libssh.org"},
+		ServerMACs:          []string{"hmac-sha2-256-etm@openssh.com", "hmac-sha2-256", "hmac-sha1", "hmac-sha1-96"},
+		KeygenPath:          "ssh-keygen",
+		MinimumKeySizeCheck: true,
+		MinimumKeySizes:     map[string]int{"ed25519": 256, "ecdsa": 256, "rsa": 2048},
 	}
 
 	// Security settings
@@ -679,7 +680,7 @@ func NewContext() {
 		}
 	}
 
-	SSH.MinimumKeySizeCheck = sec.Key("MINIMUM_KEY_SIZE_CHECK").MustBool()
+	SSH.MinimumKeySizeCheck = sec.Key("MINIMUM_KEY_SIZE_CHECK").MustBool(SSH.MinimumKeySizeCheck)
 	minimumKeySizes := Cfg.Section("ssh.minimum_key_sizes").Keys()
 	for _, key := range minimumKeySizes {
 		if key.MustInt() != -1 {

routers/repo/settings_test.go

@@ -50,7 +50,7 @@ func TestAddReadOnlyDeployKey(t *testing.T) {
 
 	addKeyForm := auth.AddKeyForm{
 		Title:   "read-only",
-		Content: "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQDAu7tvIvX6ZHrRXuZNfkR3XLHSsuCK9Zn3X58lxBcQzuo5xZgB6vRwwm/QtJuF+zZPtY5hsQILBLmF+BZ5WpKZp1jBeSjH2G7lxet9kbcH+kIVj0tPFEoyKI9wvWqIwC4prx/WVk2wLTJjzBAhyNxfEq7C9CeiX9pQEbEqJfkKCQ== nocomment\n",
+		Content: "ssh-rsa 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 nocomment\n",
 	}
 	DeployKeysPost(ctx, addKeyForm)
 	assert.EqualValues(t, http.StatusFound, ctx.Resp.Status())
@@ -78,7 +78,7 @@ func TestAddReadWriteOnlyDeployKey(t *testing.T) {
 
 	addKeyForm := auth.AddKeyForm{
 		Title:      "read-write",
-		Content:    "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQDAu7tvIvX6ZHrRXuZNfkR3XLHSsuCK9Zn3X58lxBcQzuo5xZgB6vRwwm/QtJuF+zZPtY5hsQILBLmF+BZ5WpKZp1jBeSjH2G7lxet9kbcH+kIVj0tPFEoyKI9wvWqIwC4prx/WVk2wLTJjzBAhyNxfEq7C9CeiX9pQEbEqJfkKCQ== nocomment\n",
+		Content:    "ssh-rsa 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 nocomment\n",
 		IsWritable: true,
 	}
 	DeployKeysPost(ctx, addKeyForm)