认证码Token加密解密代码 若有用你下载便是

详细介绍了AES-CMAC的算法的原理与实现，附有C语言写的样例程序。 以下是原文的introduction： The National Institute of Standards and Technology (NIST) has recently specified the Cipher-based Message Authentication Code(CMAC). CMAC [NIST-CMAC] is a keyed hash function that is based on a symmetric key block cipher, such as the Advanced Encryption Standard [NIST-AES]. CMAC is equivalent to the One-Key CBC MAC1 (OMAC1) submitted by Iwata and Kurosawa [OMAC1a, OMAC1b]. OMAC1 is an improvement of the eXtended Cipher Block Chaining mode (XCBC) submitted by Black and Rogaway [XCBCa, XCBCb], which itself is an improvement of the basic Cipher Block Chaining-Message Authentication Code (CBC-MAC). XCBC efficiently addresses the security deficiencies of CBC-MAC, and OMAC1 efficiently reduces the key size of XCBC. AES-CMAC provides stronger assurance of data integrity than a checksum or an error-detecting code. The verification of a checksum or an error-detecting code detects only accidental modifications of the data, while CMAC is designed to detect intentional, unauthorized modifications of the data, as well as accidental modifications. AES-CMAC achieves a security goal similar to that of HMAC [RFC-HMAC]. Since AES-CMAC is based on a symmetric key block cipher, AES, and HMAC is based on a hash function, such as SHA-1, AES-CMAC is appropriate for information systems in which AES is more readily available than a hash function. This memo specifies the authentication algorithm based on CMAC with AES-128. This new authentication algorithm is named AES-CMAC.