.Dd March 22, 2007 .Dt CCHMAC 3 .Os .Sh NAME .Nm CCHmacInit , .Nm CCHmacUpdate , .Nm CCHmacFinal , .Nm CCHmac .Nd Common HMAC Algorithm Interfaces .Sh LIBRARY These functions are found in libSystem. .Sh SYNOPSIS .In CommonCrypto/CommonHMAC.h .Ft void .Fn CCHmacInit "CCHmacContext *ctx" "CCHmacAlgorithm algorithm" "const void *key" "size_t keyLength" .Ft void .Fn CCHmacUpdate "CCHmacContext *ctx" "const void *data" "size_t dataLength" .Ft void .Fn CCHmacFinal "CCHmacContext *ctx" "void *macOut" .Ft void .Fn CCHmac "CCHmacAlgorithm algorithm" "const void *key" "size_t keyLength" "const void *data" "size_t dataLength" "void *macOut" .Sh DESCRIPTION This interface provides access to a number of HMAC algorithms. The following algorithms are available: .Bl -tag -width "kCCHmacAlgSHA224" .It kCCHmacAlgSHA1 - HMAC with SHA1 digest .It kCCHmacAlgMD5 - HMAC with MD5 digest .It kCCHmacAlgSHA256 - HMAC with SHA256 digest .It kCCHmacAlgSHA384 - HMAC with SHA384 digest .It kCCHmacAlgSHA224 - HMAC with SHA224 digest .It kCCHmacAlgSHA512 - HMAC with SHA512 digest .El .Pp The object declared in this interface, CCHmacContext, provides a handle for use with the .Fn CCHmacInit .Fn CCHmacUpdate and .Fn CCHmacFinal calls to complete the HMAC operation. In addition there is a one shot function, .Fn CCHmac that performs a complete HMAC on a single piece of data. .Sh SEE ALSO .Xr CC_MD5 3cc , .Xr CC_SHA 3cc , .Xr CC_crypto 3cc , .Xr CCCrypto 3cc