Message Authentication Code (MAC)

Programmer Reference : Cryptography : Message Authentication Code (MAC)

Module Implementation: OpenSSLCryptoInterfaceMAC

This module implements message authentication code (MAC) algorithms such as HMAC and CMAC. In addition to data integrity, MAC also provides authentication.

Note: Internal classes are italicized and will only contain a short description.

See the class-side examples in the OpenSSLMessageAuthenticationCodeExamples class for additional usage detail.

MAC

OSSslMacCtx: Abstract MAC context class.

OSSslMac

Abstract superclass of concrete MAC algorithms.

Class methods: API

allMacNames

Answer a sorted listing of all supported mac names

Answers:

< SequenceableCollection>

allMacsCollect: aBlock

Answer a Collection that is created by iteratively

evaluating the one argument block, @aBlock using each element of

the receiver as an argument.

Fail if @aBlock is not a one-argument Block.

Arguments:

aBlock - <Block> 1-arg

Answers:

allMacsDo: aBlock

Evaluate a one-arg block on all known macs.

Arguments:

aBlock - <Block> 1-arg block with mac <OSSslMac> as param

allMacsSelect: aBlock

Answer a SequenceableCollection that is created by iteratively evaluating

the one argument block, @aBlock using an element of receiver and

adding the element to the returned SequenceableCollection only if

aBlock evaluates to the Boolean true.

Fail if aBlock is not a one-argument Block.

Fail if the result of @aBlock is not a Boolean.

Arguments:

aBlock - <Block> 1-arg

Answers:

Class methods: Creation

named: aMacName

Answer the <OSSslMac> associated with @aMacName.

This performs a fast lookup, and if that fails then it queries OpenSSL.

If OpenSSL is unable to locate it, it could be because the library was compiled

in such a way that it left it out.

Arguments:

aMacName - <String>

Answers:

<OSSslMac> - mac object

<OpenSSLError> - error object

Class methods: Factory

cmac

Answer a mac object configured for CMAC

hmac

Answer a mac object configured for HMAC

Instance methods: Accessing

longName

Answer the longName <String> of this mac

Answers:

<String> - longName

name

Answer the shortName <String> of this mac

Answers:

<String> - shortName

shortName

Answer the shortName <String> of this mac

Answers:

<String> - shortName

Instance methods: Equality

= anOSSslMac

Two MAC algorithms are considered equal if they are both OSSslMac objects

and they share the same context class

Instance methods: High-Level API - MAC

digest: aByteObject key: aKey using: anObject

Compute and Answer the message authentication code (MAC) <ByteArray> for

@aByteObject using the key @aKey and mac parameter @anObject.

For HMAC, the mac parameter is a digest <OSSslDigest>

For CMAC, the mac paramter is a cipher <OSSslCipher>

Arguments:

aByteObject - @see implementors of isOpenSSLByteObject for types

aKey - @see implementors of isOpenSSLByteObject for types

anObject - <Object>

Answers:

<ByteArray> computed keyed hash for message authentication

<OpenSSLError> error object

printableDigest: aByteObject key: aKey using: anObject

Compute and Answer the message authentication code (MAC) <String> in hex for

@aByteObject using the key @aKey and mac parameter @anObject.

For HMAC, the mac parameter is a digest <OSSslDigest>

For CMAC, the mac paramter is a cipher <OSSslCipher>

Arguments:

aByteObject - @see implementors of isOpenSSLByteObject for types

aKey - @see implementors of isOpenSSLByteObject for types

anObject - <Object>

Answers:

<String> computed keyed hash for message authentication in hex

<OpenSSLError> error object

HMAC

HMAC is a Message Authentication Code which is based on a hash function.

OSSslHmacCtx

Instance of this class are used to represent the calculation of an HMAC against a set of data.

Class methods: Creation

createNewFromDigest: anOSSslDigest key: aKey

Create a new HMAC_CTX instance and initialize it with the provided digest anOSSslDigest and key aKey

Arguments:

anOSSslDigest - <OSSslDigest>

aKey - @see implementors of isOpenSSLByteObject for types

Answers:

<OSSslHmacCtx> - new instance

<OpenSSLError compatible error> - error object

Instance methods: Accessing

digestSize

Answer the size of the digest.

Answers:

<Integer> - digest size

digestSize: anInteger

Set the internal state of the digest size.

Arguments:

anInteger - <Integer> long integer value

osDigest: anOSSslDigest key: aKey

Set the key and digest of this HMAC. This is required when using the Low-Level API because its not required to (re)pass in the key and digest on every call...therefore it must be known that they were set for safety.

Arguments:

anOSSslDigest - <OSSslDigest>

aKey - @see implementors of isOpenSSLByteObject for types

CMAC

CMAC is a Message Authentication Code which is based on a cipher.

OSSslCmacCtx

Instance of this class are used to represent the calculation of an HMAC against a set of data.

Class methods: Creation

createNewFromCipher: anOSSslCipher key: aKey

Create a new CMAC_CTX instance and initialize it with the provided digest @anOSSslCipher and key @aKey

Arguments:

anOSSslCipher - <OSSslCipher>

aKey - @see implementors of isOpenSSLByteObject for types

Answers:

<OSSslCmacCtx> - new instance

<OpenSSLError compatible error> - error object

Instance methods: Accessing

osCipher: anOSSslCipher key: aKey

Set the key and cipher of this CMAC.

Answers:

anOSSslCipher - <OSSslCipher>

aKey - @see implementors of isOpenSSLByteObject for types

osCipherCtx

Answer the cipher ctx that was created by the CMAC context.

We do not own this memory and do not need to track it, so create a static reference

Answers:

Extensions

OSSslCipher

cmacDigest: aByteObject key: aKey

Compute and Answer the message authentication code (MAC) <ByteArray> for @aByteObject using the key @aKey and this cipher instance.

Arguments:

aByteObject - @see implementors of isOpenSSLByteObject for types

aKey - @see implementors of isOpenSSLByteObject for types

Answers:

<ByteArray> - computed message authentication code

cmacPrintableDigest: aByteObject key: aKey

Compute and Answer the message authentication code (MAC) <String> for aByteObject using the key aKey and this cipher instance.

Arguments:

aByteObject - a @see implementors of isOpenSSLByteObject for types

aKey - @see implementors of isOpenSSLByteObject for types

Answers:

<String> computed keyed hash for message authentication in hex

OSSslDigest

hmacDigest: aByteObject key: aKey

Compute and Answer the message authentication code (MAC) <ByteArray> for aByteObject using the key aKey and this message digest instance.

Arguments:

aByteObject - @see implementors of isOpenSSLByteObject for types

aKey - @see implementors of isOpenSSLByteObject for types

Answers:

<ByteArray> - computed message authentication code

hmacPrintableDigest: aByteObject key: aKey

Compute and Answer the message authentication code (MAC) <String> for aByteObject using the key aKey and this message digest instance.

Arguments:

aByteObject - @see implementors of isOpenSSLByteObject for types

aKey - @see implementors of isOpenSSLByteObject for types

Answers:

<String> computed keyed hash for message authentication in hex

Last modified date: 08/09/2017