masker

Overview ¶

Package masker provides a flexible data masking system for Go applications, allowing you to protect sensitive information in various data types.

The package wraps and extends github.com/showa-93/go-mask functionality, providing additional convenience methods and pre-configured masking rules for common sensitive fields.

By default, the package initializes with common masking rules for sensitive fields:

• Password/password: 4 character mask
• SigningKey/signing_key: 32 character mask
• Authorization/authorization: 32 character mask

Basic usage with the default masker:

type User struct {
	Username string
	Password string `mask:"filled4"`
}

user := User{
	Username: "john",
	Password: "secret123",
}

masked, err := masker.Mask(user)
if err != nil {
	log.Fatal(err)
}

Available Masking Types:

• hash: Masks and hashes (sha1) a string
• fixed: Masks with a fixed length (8 characters)
• filled: Masks the entire string or with specified length
• random: For numeric types, generates random values within range
• zero: Sets the field to its zero value

Custom Masking:

m := &Masker{...}
m.RegisterMaskStringFunc("custom", func(arg, value string) (string, error) {
	return strings.Repeat("*", len(value)), nil
})

Field Registration:

m := &Masker{...}
m.RegisterMaskField("api_key", "filled32")

Configuration:

The package supports various configuration options:

m.SetTagName("mask")      // Change the struct tag name
m.SetMaskChar("*")        // Change the masking character
m.Cache(true)             // Enable/disable type information caching

Supported Types:

• string (MaskStringFunc)
• uint (MaskUintFunc)
• int (MaskIntFunc)
• float64 (MaskFloat64Func)
• any (MaskAnyFunc)

Thread Safety:

The package maintains a global Default masker instance that is safe for concurrent use after initialization. Custom masker instances should be handled with appropriate synchronization if modified after initialization.

Performance:

Type information caching is enabled by default to improve performance. For dynamic structures where fields change frequently, caching can be disabled using the Cache(false) method.

For additional information and updates, visit: https://github.com/goliatone/go-masker