Package com.ongres.scram.common
Class ScramFunctions
java.lang.Object
com.ongres.scram.common.ScramFunctions
Utility functions (mostly crypto) for SCRAM.
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final byte[]
private static final byte[]
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic String
authMessage
(ClientFirstMessage clientFirstMessage, ServerFirstMessage serverFirstMessage, byte[] cbindData) The AuthMessage is computed by concatenating messages from the authentication exchange.static byte[]
clientKey
(ScramMechanism scramMechanism, byte[] saltedPassword) Generates a client key, from the salted password.static byte[]
clientProof
(byte[] clientKey, byte[] clientSignature) Computes the SCRAM client proof to be sent to the server on the client-final-message.static byte[]
clientSignature
(ScramMechanism scramMechanism, byte[] storedKey, String authMessage) Computes the SCRAM client signature.static byte[]
hash
(ScramMechanism scramMechanism, byte[] message) Computes the hash function of a given value, based on the SCRAM mechanism hash function.static byte[]
hmac
(ScramMechanism scramMechanism, byte[] key, byte[] message) Computes the HMAC of the message and key, using the given SCRAM mechanism.static String
nonce
(int nonceSize, SecureRandom random) Generates a random string (called a 'nonce'), composed of ASCII printable characters, except comma (',').static byte[]
salt
(int saltSize, SecureRandom random) Generates a random salt that can be used to generate a salted password.static byte[]
saltedPassword
(ScramMechanism scramMechanism, StringPreparation stringPreparation, char[] password, byte[] salt, int iterationCount) Compute the salted password, based on the given SCRAM mechanism, the String preparation algorithm, the provided salt and the number of iterations.static byte[]
serverKey
(ScramMechanism scramMechanism, byte[] saltedPassword) Generates a server key, from the salted password.static byte[]
serverSignature
(ScramMechanism scramMechanism, byte[] serverKey, String authMessage) Compute the SCRAM server signature.static byte[]
storedKey
(ScramMechanism scramMechanism, byte[] clientKey) Generates a stored key, from the salted password.static boolean
verifyClientProof
(ScramMechanism scramMechanism, byte[] clientProof, byte[] storedKey, String authMessage) Verifies that a provided client proof is correct.static boolean
verifyServerSignature
(ScramMechanism scramMechanism, byte[] serverKey, String authMessage, byte[] serverSignature) Verifies that a provided server proof is correct.
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Field Details
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CLIENT_KEY_HMAC_MESSAGE
private static final byte[] CLIENT_KEY_HMAC_MESSAGE -
SERVER_KEY_HMAC_MESSAGE
private static final byte[] SERVER_KEY_HMAC_MESSAGE
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Constructor Details
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ScramFunctions
private ScramFunctions()
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Method Details
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saltedPassword
public static byte[] saltedPassword(ScramMechanism scramMechanism, StringPreparation stringPreparation, char[] password, byte[] salt, int iterationCount) Compute the salted password, based on the given SCRAM mechanism, the String preparation algorithm, the provided salt and the number of iterations.SaltedPassword := Hi(Normalize(password), salt, i)
- Parameters:
scramMechanism
- The SCRAM mechanismstringPreparation
- The String preparationpassword
- The non-salted passwordsalt
- The bytes representing the saltiterationCount
- The number of iterations- Returns:
- The salted password
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hmac
Computes the HMAC of the message and key, using the given SCRAM mechanism.HMAC(key, str)
- Parameters:
scramMechanism
- The SCRAM mechanismkey
- The key used to initialize the MACmessage
- The message to compute the HMAC- Returns:
- The computed HMAC
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clientKey
Generates a client key, from the salted password.ClientKey := HMAC(SaltedPassword, "Client Key")
- Parameters:
scramMechanism
- The SCRAM mechanismsaltedPassword
- The salted password- Returns:
- The client key
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serverKey
Generates a server key, from the salted password.ServerKey := HMAC(SaltedPassword, "Server Key")
- Parameters:
scramMechanism
- The SCRAM mechanismsaltedPassword
- The salted password- Returns:
- The server key
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hash
Computes the hash function of a given value, based on the SCRAM mechanism hash function.H(str)
- Parameters:
scramMechanism
- The SCRAM mechanismmessage
- The message to hash- Returns:
- The hashed value
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storedKey
Generates a stored key, from the salted password.StoredKey := H(ClientKey)
- Parameters:
scramMechanism
- The SCRAM mechanismclientKey
- The client key- Returns:
- The stored key
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clientSignature
public static byte[] clientSignature(ScramMechanism scramMechanism, byte[] storedKey, String authMessage) Computes the SCRAM client signature.ClientSignature := HMAC(StoredKey, AuthMessage)
- Parameters:
scramMechanism
- The SCRAM mechanismstoredKey
- The stored keyauthMessage
- The auth message- Returns:
- The client signature
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clientProof
public static byte[] clientProof(byte[] clientKey, byte[] clientSignature) Computes the SCRAM client proof to be sent to the server on the client-final-message.ClientProof := ClientKey XOR ClientSignature
- Parameters:
clientKey
- The client keyclientSignature
- The client signature- Returns:
- The client proof
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serverSignature
public static byte[] serverSignature(ScramMechanism scramMechanism, byte[] serverKey, String authMessage) Compute the SCRAM server signature.ServerSignature := HMAC(ServerKey, AuthMessage)
- Parameters:
scramMechanism
- The SCRAM mechanismserverKey
- The server keyauthMessage
- The auth message- Returns:
- The server signature
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verifyClientProof
public static boolean verifyClientProof(ScramMechanism scramMechanism, byte[] clientProof, byte[] storedKey, String authMessage) Verifies that a provided client proof is correct.- Parameters:
scramMechanism
- The SCRAM mechanismclientProof
- The provided client proofstoredKey
- The stored keyauthMessage
- The auth message- Returns:
- True if the client proof is correct
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verifyServerSignature
public static boolean verifyServerSignature(ScramMechanism scramMechanism, byte[] serverKey, String authMessage, byte[] serverSignature) Verifies that a provided server proof is correct.- Parameters:
scramMechanism
- The SCRAM mechanismserverKey
- The server keyauthMessage
- The auth messageserverSignature
- The provided server signature- Returns:
- True if the server signature is correct
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nonce
Generates a random string (called a 'nonce'), composed of ASCII printable characters, except comma (',').- Parameters:
nonceSize
- The length of the nonce, in characters/bytesrandom
- The SecureRandom to use- Returns:
- The String representing the nonce
- Throws:
IllegalArgumentException
- if the nonceSize is not positive, or if random is null
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salt
Generates a random salt that can be used to generate a salted password.- Parameters:
saltSize
- The length of the salt, in bytesrandom
- The SecureRandom to use- Returns:
- The bye[] representing the salt
- Throws:
IllegalArgumentException
- if the saltSize is not positive, or if random is null
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authMessage
public static String authMessage(ClientFirstMessage clientFirstMessage, ServerFirstMessage serverFirstMessage, byte[] cbindData) The AuthMessage is computed by concatenating messages from the authentication exchange.AuthMessage := client-first-message-bare + "," + server-first-message + "," + client-final-message-without-proof
- Parameters:
clientFirstMessage
- theClientFirstMessage
serverFirstMessage
- theServerFirstMessage
cbindData
- the channel binding data, or null- Returns:
- the AuthMessage
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