1 files changed, 76 insertions, 4 deletions
diff --git a/vendor/github.com/lib/pq/ssl_permissions.go b/vendor/github.com/lib/pq/ssl_permissions.go
index 014af6a..d587f10 100644
--- a/vendor/github.com/lib/pq/ssl_permissions.go
+++ b/vendor/github.com/lib/pq/ssl_permissions.go
@@ -3,7 +3,28 @@
 
 package pq
 
-import "os"
+import (
+	"errors"
+	"os"
+	"syscall"
+)
+
+const (
+	rootUserID = uint32(0)
+
+	// The maximum permissions that a private key file owned by a regular user
+	// is allowed to have. This translates to u=rw.
+	maxUserOwnedKeyPermissions os.FileMode = 0600
+
+	// The maximum permissions that a private key file owned by root is allowed
+	// to have. This translates to u=rw,g=r.
+	maxRootOwnedKeyPermissions os.FileMode = 0640
+)
+
+var (
+	errSSLKeyHasUnacceptableUserPermissions = errors.New("permissions for files not owned by root should be u=rw (0600) or less")
+	errSSLKeyHasUnacceptableRootPermissions = errors.New("permissions for root owned files should be u=rw,g=r (0640) or less")
+)
 
 // sslKeyPermissions checks the permissions on user-supplied ssl key files.
 // The key file should have very little access.
@@ -14,8 +35,59 @@ func sslKeyPermissions(sslkey string) error {
 	if err != nil {
 		return err
 	}
-	if info.Mode().Perm()&0077 != 0 {
-		return ErrSSLKeyHasWorldPermissions
+
+	err = hasCorrectPermissions(info)
+
+	// return ErrSSLKeyHasWorldPermissions for backwards compatability with
+	// existing code.
+	if err == errSSLKeyHasUnacceptableUserPermissions || err == errSSLKeyHasUnacceptableRootPermissions {
+		err = ErrSSLKeyHasWorldPermissions
 	}
-	return nil
+	return err
+}
+
+// hasCorrectPermissions checks the file info (and the unix-specific stat_t
+// output) to verify that the permissions on the file are correct.
+//
+// If the file is owned by the same user the process is running as,
+// the file should only have 0600 (u=rw). If the file is owned by root,
+// and the group matches the group that the process is running in, the
+// permissions cannot be more than 0640 (u=rw,g=r). The file should
+// never have world permissions.
+//
+// Returns an error when the permission check fails.
+func hasCorrectPermissions(info os.FileInfo) error {
+	// if file's permission matches 0600, allow access.
+	userPermissionMask := (os.FileMode(0777) ^ maxUserOwnedKeyPermissions)
+
+	// regardless of if we're running as root or not, 0600 is acceptable,
+	// so we return if we match the regular user permission mask.
+	if info.Mode().Perm()&userPermissionMask == 0 {
+		return nil
+	}
+
+	// We need to pull the Unix file information to get the file's owner.
+	// If we can't access it, there's some sort of operating system level error
+	// and we should fail rather than attempting to use faulty information.
+	sysInfo := info.Sys()
+	if sysInfo == nil {
+		return ErrSSLKeyUnknownOwnership
+	}
+
+	unixStat, ok := sysInfo.(*syscall.Stat_t)
+	if !ok {
+		return ErrSSLKeyUnknownOwnership
+	}
+
+	// if the file is owned by root, we allow 0640 (u=rw,g=r) to match what
+	// Postgres does.
+	if unixStat.Uid == rootUserID {
+		rootPermissionMask := (os.FileMode(0777) ^ maxRootOwnedKeyPermissions)
+		if info.Mode().Perm()&rootPermissionMask != 0 {
+			return errSSLKeyHasUnacceptableRootPermissions
+		}
+		return nil
+	}
+
+	return errSSLKeyHasUnacceptableUserPermissions
 }