Documentation
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Overview ¶
Package input provides security-focused input validation and basic defense-in-depth sanitization utilities.
This package implements conservative validation functions for common input types including:
- Email addresses with DNS-style domain label checks
- Safe HTTP and HTTPS URLs plus safe absolute relative URL paths
- Phone numbers with E.164-compatible digit bounds
- HTTP tokens (RFC 7230)
The sanitizer helpers are not substitutes for context-aware HTML sanitizers, parameterized SQL queries, or output encoding.
Example usage:
import "github.com/spcent/plumego/security/input"
// Validate email
if !input.ValidateEmail("user@example.com") {
// Invalid email
}
// Validate URL
if !input.ValidateURL("https://example.com") {
// Invalid URL
}
// Validate phone number (E.164)
if !input.ValidatePhone("+1234567890") {
// Invalid phone number
}
// Check if string contains dangerous characters
if input.ContainsDangerousChars(userInput) {
// Contains dangerous characters
}
Index ¶
- func BestEffortSanitizeHTML(s string) string
- func BestEffortSanitizeSQL(s string) string
- func ContainsDangerousChars(s string) bool
- func IsHeaderName(value string) bool
- func IsHeaderValue(value string) bool
- func IsToken(value string) bool
- func StripControlChars(s string) string
- func TrimWhitespace(s string) string
- func ValidateEmail(email string) bool
- func ValidatePhone(phone string) bool
- func ValidatePublicURL(rawURL string) bool
- func ValidateURL(rawURL string) bool
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func BestEffortSanitizeHTML ¶
BestEffortSanitizeHTML applies a lossy, best-effort HTML cleanup pass.
This helper removes a small set of common script and inline-handler patterns for defense-in-depth only. It is not a complete HTML parser or sanitizer and must not be used as the sole control for rendering untrusted HTML.
Example:
import "github.com/spcent/plumego/security/input" cleaned := input.BestEffortSanitizeHTML(userInput)
func BestEffortSanitizeSQL ¶
BestEffortSanitizeSQL applies a lossy, best-effort SQL text cleanup pass.
WARNING: This is NOT a substitute for parameterized queries. Always use parameterized queries for database operations. This helper removes a small set of common comment, separator, and keyword patterns for defense-in-depth scenarios only.
Example:
import "github.com/spcent/plumego/security/input" // Still use parameterized queries! cleaned := input.BestEffortSanitizeSQL(userInput)
func ContainsDangerousChars ¶
ContainsDangerousChars checks for characters commonly used in injection attacks.
Returns true if the string contains potentially dangerous characters.
Example:
import "github.com/spcent/plumego/security/input"
if input.ContainsDangerousChars(userInput) {
// Handle potentially dangerous input
}
func IsHeaderName ¶
IsHeaderName reports whether value is safe for use as an HTTP header name.
Header names must be valid HTTP tokens according to RFC 7230.
Example:
import "github.com/spcent/plumego/security/input"
if input.IsHeaderName("X-Custom-Header") {
// Valid header name
}
func IsHeaderValue ¶
IsHeaderValue reports whether value is safe for use as an HTTP header value. It rejects control characters that can lead to response splitting.
Header values must be valid UTF-8 and must not contain ASCII control characters except horizontal tab.
Example:
import "github.com/spcent/plumego/security/input"
if input.IsHeaderValue("some value") {
// Safe to use as header value
}
func IsToken ¶
IsToken reports whether value is a valid HTTP token (RFC 7230).
HTTP tokens are used in header names, media types, and other HTTP constructs. A token consists of ASCII letters, digits, and certain special characters.
Example:
import "github.com/spcent/plumego/security/input"
if input.IsToken("Content-Type") {
// Valid HTTP token
}
Valid tokens include:
- Letters (a-z, A-Z)
- Digits (0-9)
- Special characters: ! # $ % & ' * + - . ^ _ ` | ~
func StripControlChars ¶
StripControlChars removes ASCII control characters except newline and tab.
This function removes characters that could cause display issues or be used for terminal injection attacks.
Example:
import "github.com/spcent/plumego/security/input" clean := input.StripControlChars(userInput)
func TrimWhitespace ¶
TrimWhitespace removes leading and trailing whitespace and normalizes internal whitespace.
This function collapses multiple consecutive whitespace characters into a single space and removes leading/trailing whitespace.
Example:
import "github.com/spcent/plumego/security/input"
normalized := input.TrimWhitespace(" hello world ")
// Returns: "hello world"
func ValidateEmail ¶
ValidateEmail performs security-focused email validation.
Returns true if the email appears valid. This is a basic check for security purposes, not a comprehensive email validation.
Example:
import "github.com/spcent/plumego/security/input"
if !input.ValidateEmail(userEmail) {
// Reject invalid email
}
func ValidatePhone ¶
ValidatePhone performs basic phone number validation.
Returns true if the phone number appears valid. This is a basic check that accepts E.164 format and common phone number patterns.
Example:
import "github.com/spcent/plumego/security/input"
if !input.ValidatePhone(userPhone) {
// Reject invalid phone
}
func ValidatePublicURL ¶
ValidatePublicURL checks whether rawURL is an absolute HTTP(S) URL whose literal host is suitable for server-side fetch allow-lists.
It rejects relative paths, localhost names, loopback, private, link-local, multicast, unspecified, and metadata-service IP targets. It does not perform DNS resolution; callers that resolve hostnames must still enforce the same checks on every resolved address.
func ValidateURL ¶
ValidateURL checks URL shape, allowed schemes, and unsafe relative forms.
Returns true if the URL is syntactically valid for common redirect/link use. This function rejects javascript:, data:, file:, vbscript:, embedded credentials, malformed URLs, and unsafe relative paths. It does not make a URL safe for server-side fetching because hostnames can resolve to private addresses. Use ValidatePublicURL for SSRF-sensitive fetch targets.
Example:
import "github.com/spcent/plumego/security/input"
if !input.ValidateURL(userURL) {
// Reject invalid or unsafe URL
}
Types ¶
This section is empty.
Source Files