org.keycloak.models.utils.HmacOTP クラス

org.keycloak.models.utils.HmacOTP の継承関係図

org.keycloak.models.utils.HmacOTP 連携図

公開メンバ関数
	HmacOTP (int numberDigits, String algorithm, int delayWindow)
String	generateHOTP (String key, int counter)
int	validateHOTP (String token, String key, int counter)
String	generateOTP (String key, String counter, int returnDigits, String crypto)

静的公開メンバ関数
static String	generateSecret (int length)

静的公開変数類
static final String	HMAC_SHA1 = "HmacSHA1"
static final String	HMAC_SHA256 = "HmacSHA256"
static final String	HMAC_SHA512 = "HmacSHA512"
static final String	DEFAULT_ALGORITHM = HMAC_SHA1
static final int	DEFAULT_NUMBER_DIGITS = 6

限定公開変数類
final String	algorithm
final int	numberDigits
final int	lookAheadWindow

非公開メンバ関数
byte []	hmac_sha1 (String crypto, byte[] keyBytes, byte[] text)
byte []	hexStr2Bytes (String hex)

静的非公開変数類
static final int []	DIGITS_POWER = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000}

詳解

著者

Bill Burke

バージョン

Revision

1

構築子と解体子

HmacOTP()

org.keycloak.models.utils.HmacOTP.HmacOTP ( int  numberDigits, String  algorithm, int  delayWindow  )

inline

                                                                        {
        this.numberDigits = numberDigits;
        this.algorithm = algorithm;
        this.lookAheadWindow = delayWindow;
    }

関数詳解

generateHOTP()

String org.keycloak.models.utils.HmacOTP.generateHOTP ( String  key, int  counter  )

inline

                                                        {
        String steps = Integer.toHexString(counter).toUpperCase();

        // Just get a 16 digit string
        while (steps.length() < 16)
            steps = "0" + steps;

        return generateOTP(key, steps, numberDigits, algorithm);

    }

generateOTP()

String org.keycloak.models.utils.HmacOTP.generateOTP ( String  key, String  counter, int  returnDigits, String  crypto  )

inline

This method generates an OTP value for the given set of parameters.

引数

key	the shared secret, HEX encoded
counter	a value that reflects a time
returnDigits	number of digits to return
crypto	the crypto function to use

戻り値

A numeric String in base 10 that includes return digits

例外

java.security.GeneralSecurityException

                                                                                           {
        String result = null;
        byte[] hash;

        // Using the counter
        // First 8 bytes are for the movingFactor
        // Complaint with base RFC 4226 (HOTP)
        while (counter.length() < 16)
            counter = "0" + counter;

        // Get the HEX in a Byte[]
        byte[] msg = hexStr2Bytes(counter);

        // Adding one byte to get the right conversion
        // byte[] k = hexStr2Bytes(key);
        byte[] k = key.getBytes();

        hash = hmac_sha1(crypto, k, msg);

        // put selected bytes into result int
        int offset = hash[hash.length - 1] & 0xf;

        int binary = ((hash[offset] & 0x7f) << 24) | ((hash[offset + 1] & 0xff) << 16) | ((hash[offset + 2] & 0xff) << 8)
                | (hash[offset + 3] & 0xff);

        int otp = binary % DIGITS_POWER[returnDigits];

        result = Integer.toString(otp);

        while (result.length() < returnDigits) {
            result = "0" + result;
        }
        return result;
    }

generateSecret()

static String org.keycloak.models.utils.HmacOTP.generateSecret ( int  length )

inlinestatic

                                                    {
        String chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVW1234567890";
        SecureRandom r = new SecureRandom();
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < length; i++) {
            char c = chars.charAt(r.nextInt(chars.length()));
            sb.append(c);
        }
        return sb.toString();
    }

hexStr2Bytes()

byte [] org.keycloak.models.utils.HmacOTP.hexStr2Bytes ( String  hex )

inlineprivate

This method converts HEX string to Byte[]

引数

hex	the HEX string

戻り値

A byte array

                                            {
        // Adding one byte to get the right conversion
        // values starting with "0" can be converted
        byte[] bArray = new BigInteger("10" + hex, 16).toByteArray();

        // Copy all the REAL bytes, not the "first"
        byte[] ret = new byte[bArray.length - 1];
        for (int i = 0; i < ret.length; i++)
            ret[i] = bArray[i + 1];
        return ret;
    }

hmac_sha1()

byte [] org.keycloak.models.utils.HmacOTP.hmac_sha1 ( String  crypto, byte []  keyBytes, byte []  text  )

inlineprivate

This method uses the JCE to provide the crypto algorithm. HMAC computes a Hashed Message Authentication Code with the crypto hash algorithm as a parameter.

引数

crypto	the crypto algorithm (HmacSHA1, HmacSHA256, HmacSHA512)
keyBytes	the bytes to use for the HMAC key
text	the message or text to be authenticated.

例外

java.security.NoSuchAlgorithmException
java.security.InvalidKeyException

                                                                          {
        byte[] value;

        try {
            Mac hmac = Mac.getInstance(crypto);
            SecretKeySpec macKey = new SecretKeySpec(keyBytes, "RAW");

            hmac.init(macKey);

            value = hmac.doFinal(text);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

        return value;
    }

validateHOTP()

int org.keycloak.models.utils.HmacOTP.validateHOTP ( String  token, String  key, int  counter  )

inline

引数

token
key
counter

戻り値

-1 if not a match. A positive number means successful validation. This positive number is also the new value of the counter

                                                                   {

        int newCounter = counter;
        for (newCounter = counter; newCounter <= counter + lookAheadWindow; newCounter++) {
            String candidate = generateHOTP(key, newCounter);
            if (candidate.equals(token)) {
                return newCounter + 1;
            }

        }
        return -1;
    }

メンバ詳解

algorithm

final String org.keycloak.models.utils.HmacOTP.algorithm

protected

DEFAULT_ALGORITHM

final String org.keycloak.models.utils.HmacOTP.DEFAULT_ALGORITHM = HMAC_SHA1

static

DEFAULT_NUMBER_DIGITS

final int org.keycloak.models.utils.HmacOTP.DEFAULT_NUMBER_DIGITS = 6

static

DIGITS_POWER

final int [] org.keycloak.models.utils.HmacOTP.DIGITS_POWER = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000}

staticprivate

HMAC_SHA1

final String org.keycloak.models.utils.HmacOTP.HMAC_SHA1 = "HmacSHA1"

static

HMAC_SHA256

final String org.keycloak.models.utils.HmacOTP.HMAC_SHA256 = "HmacSHA256"

static

HMAC_SHA512

final String org.keycloak.models.utils.HmacOTP.HMAC_SHA512 = "HmacSHA512"

static

lookAheadWindow

final int org.keycloak.models.utils.HmacOTP.lookAheadWindow

protected

numberDigits

final int org.keycloak.models.utils.HmacOTP.numberDigits

protected

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このクラス詳解は次のファイルから抽出されました:

• D:/AppData/doxygen/keycloak/src/keycloak/src/main/java/org/keycloak/models/utils/HmacOTP.java