Package org.conscrypt

Class AddressUtils

java.lang.Object

org.conscrypt.AddressUtils

final class AddressUtils
extends Object

Utilities to check whether IP addresses meet some criteria.

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	ASCII_CASE_DIFF
private static final int	IPV4_OCTET_COUNT
private static final int	IPV6_GROUPS_PER_IPV4
private static final int	IPV6_TOTAL_GROUPS
private static final int	MAX_HEX_DIGITS_PER_GROUP
private static final int	MAX_IPV4_ADDRESS_LENGTH
private static final int	MAX_IPV4_DOTS
private static final int	MAX_IPV4_OCTET_DIGITS
private static final int	MAX_IPV4_OCTET_VALUE
private static final int	MIN_IPV4_ADDRESS_LENGTH

Constructor Summary

Constructors

Modifier	Constructor	Description
private	AddressUtils()

Method Summary

Modifier and Type	Method	Description
private static boolean	asciiEqualsIgnoreCase(String s, String expected)	Compares two ASCII strings case-insensitively.
private static boolean	isDigit(char c)	Returns true if the character is a basic ASCII digit (0-9).
private static boolean	isHexDigit(char c)	Returns true if the character is a valid hexadecimal digit (0-9, a-f, A-F).
(package private) static boolean	isLiteralIpAddress(String hostname)	Returns true if the supplied hostname is an literal IP address.
private static boolean	isValidIPv4(String s, int start, int end, boolean allowLeadingZeros)	Validates IPv4 address.
private static boolean	isValidIPv6(String s)	Validates IPv6 address.
(package private) static boolean	isValidSniHostname(String sniHostname)	Returns true when the supplied hostname is valid for SNI purposes.
private static boolean	isValidZoneId(String s, int start)	Validates the IPv6 Zone ID (Scope ID).
private static char	toLowerCaseAscii(char c)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

IPV4_OCTET_COUNT

private static final int IPV4_OCTET_COUNT

See Also:

• Constant Field Values

MAX_IPV4_OCTET_VALUE

private static final int MAX_IPV4_OCTET_VALUE

See Also:

• Constant Field Values

MAX_IPV4_OCTET_DIGITS

private static final int MAX_IPV4_OCTET_DIGITS

See Also:

• Constant Field Values

MAX_IPV4_DOTS

private static final int MAX_IPV4_DOTS

See Also:

• Constant Field Values

MIN_IPV4_ADDRESS_LENGTH

private static final int MIN_IPV4_ADDRESS_LENGTH

See Also:

• Constant Field Values

MAX_IPV4_ADDRESS_LENGTH

private static final int MAX_IPV4_ADDRESS_LENGTH

See Also:

• Constant Field Values

IPV6_TOTAL_GROUPS

private static final int IPV6_TOTAL_GROUPS

See Also:

• Constant Field Values

IPV6_GROUPS_PER_IPV4

private static final int IPV6_GROUPS_PER_IPV4

See Also:

• Constant Field Values

MAX_HEX_DIGITS_PER_GROUP

private static final int MAX_HEX_DIGITS_PER_GROUP

See Also:

• Constant Field Values

ASCII_CASE_DIFF

private static final int ASCII_CASE_DIFF

See Also:

• Constant Field Values

Constructor Details

AddressUtils

private AddressUtils()

Method Details

isValidSniHostname

static boolean isValidSniHostname(String sniHostname)

Returns true when the supplied hostname is valid for SNI purposes.

isLiteralIpAddress

static boolean isLiteralIpAddress(String hostname)

Returns true if the supplied hostname is an literal IP address.

isValidIPv4

private static boolean isValidIPv4(String s,
 int start,
 int end,
 boolean allowLeadingZeros)

Validates IPv4 address. Expects exactly 4 octets separated by dots, each octet being 0-255. Allows leading zeros (up to 3 digits per octet). Parses the substring [start, end) without allocation.

isValidIPv6

private static boolean isValidIPv6(String s)

Validates IPv6 address. Supports full, compressed (::), and embedded IPv4 formats. Also supports optional Zone ID (%zone) at the end. Scans the string in a single pass without allocations.

isValidZoneId

private static boolean isValidZoneId(String s,
 int start)

Validates the IPv6 Zone ID (Scope ID). A valid Zone ID must not be empty and must not contain any line terminators, matching the behavior of the '.' character in the original regular expression.

isDigit

private static boolean isDigit(char c)

Returns true if the character is a basic ASCII digit (0-9). We use this custom implementation instead of Character.isDigit(char) to avoid checking for other Unicode digit characters, keeping it strictly to ASCII and avoiding any locale or Unicode overhead.

isHexDigit

private static boolean isHexDigit(char c)

Returns true if the character is a valid hexadecimal digit (0-9, a-f, A-F). This is a simple range check that avoids any character class or regex compilation.

toLowerCaseAscii

private static char toLowerCaseAscii(char c)

asciiEqualsIgnoreCase

private static boolean asciiEqualsIgnoreCase(String s,
 String expected)

Compares two ASCII strings case-insensitively. We use this custom implementation instead of String.equalsIgnoreCase(String) to: 1. Avoid dependency on Guava's Ascii class. 2. Avoid locale-dependent behavior of String.equalsIgnoreCase (e.g. Turkish 'I' mapping), ensuring strictly ASCII comparison. 3. Avoid any object allocations.