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Posted 14 Dec 2007


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C++ Class Implementation of HMAC-SHA

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3.00/5 (12 votes)
2 May 2010CPOL
C++ class of HMAC-SHA1


This is my first article on CodeProject. Sorry for my poor English.

The reason I think it might be helpful that I share this HMAC-SHA1 class is because I found no related source I could refer to. This is a simple C++ class of HMAC-SHA1 with only single byte character support. You could add double bytes character support if needed. You will find this class contains only a function HMAC_SHA1 that accept test input and hash key, then generates a digest.


Thanks to Dominik Reichl, the SHA1 class I wrapped is from his amazing class. I simply implemented the HMAC algorithm on it. For MD5, you could refer to RFC. There is a detailed programming flow of it.

Using the Code

The usage of this class is extremely simple. Declare CHMAC_SHA1, call its HMAC_SHA1 function. That's it!

You may use HMAC-SHA1 in RFC 2202 test case to verify your implementation.

Following is test case 1 in RFC 2202.

#include "HMAC_SHA1.h"
BYTE Key[20] ;
BYTE digest[20] ; 

unsigned char *test = "Hi There" ; 
memset(Key, 0x0b, 20) ;
HMAC_SHA1.HMAC_SHA1(test, strlen(test), Key, sizeof(Key), digest) ;
// Check with digest equal to 0xb617318655057264e28bc0b6fb378c8ef146be00
// or not


  • 2007/12/17: Updated sample code with RFC 2202 test case 1


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Chien-Chung, Chung
Software Developer (Senior)
Taiwan Taiwan
Life is nothing but choices.

Comments and Discussions

QuestionHMAC - digest not retuning output as expected Pin
Member 1478224111-Jun-20 20:17
MemberMember 1478224111-Jun-20 20:17 
QuestionUnicode or Multi-Byte Matters? Pin
Member 1207894322-Oct-15 17:21
MemberMember 1207894322-Oct-15 17:21 
Questionfeedback Pin
Member 120473359-Oct-15 21:48
MemberMember 120473359-Oct-15 21:48 
GeneralMy vote of 5 Pin
nicklin026-Mar-13 3:57
Membernicklin026-Mar-13 3:57 
QuestionCode Segfaults with messages longer than buffersize minus digestsize Pin
Member 932791917-Sep-12 6:16
MemberMember 932791917-Sep-12 6:16 
QuestionIs the digest same as the one computed by C# code ? Pin
BeckDai12-Apr-12 17:55
MemberBeckDai12-Apr-12 17:55 
AnswerRe: Is the digest same as the one computed by C# code ? Pin
Chien-Chung, Chung7-May-12 22:49
MemberChien-Chung, Chung7-May-12 22:49 
Questionthe result is not right Pin
haolifengwang1-Jan-12 18:49
Memberhaolifengwang1-Jan-12 18:49 
AnswerRe: the result is not right Pin
Chien-Chung, Chung7-May-12 22:47
MemberChien-Chung, Chung7-May-12 22:47 
Generalhelp me Pin
kalyan41927-Aug-09 18:41
Memberkalyan41927-Aug-09 18:41 
QuestionError message Pin
Godwin Ansa5-Aug-08 3:05
MemberGodwin Ansa5-Aug-08 3:05 
AnswerRe: Error message Pin
Chien-Chung, Chung2-May-10 16:38
MemberChien-Chung, Chung2-May-10 16:38 
Generalmemset used wrongly Pin
Dante Shamest21-Jul-08 21:06
MemberDante Shamest21-Jul-08 21:06 
GeneralRe: memset used wrongly Pin
hetcorp1-Apr-09 4:41
Memberhetcorp1-Apr-09 4:41 
GeneralRe: memset used wrongly Pin
Jim Chung2-May-10 16:10
MemberJim Chung2-May-10 16:10 
Questionreceiver processing for HMAC-SHA? Pin
Adam Harding3-Jun-08 12:49
MemberAdam Harding3-Jun-08 12:49 
GeneralBugfix for long key's [modified] Pin
bruno19996-Mar-08 3:31
Memberbruno19996-Mar-08 3:31 
GeneralThanks Pin
bruno19995-Mar-08 9:37
Memberbruno19995-Mar-08 9:37 
GeneralRe: Thanks Pin
Godwin Ansa27-Aug-08 3:01
MemberGodwin Ansa27-Aug-08 3:01 

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