Undefined reference error

jacques83 · 11-12-2005, 12:53 PM

the only change that needs to be done to the above code to run is the setting of k_ipad and k_opad to the values as shown....

/* start out by storing key in pads */
bzero( k_ipad, sizeof k_ipad);
bzero( k_opad, sizeof k_opad);
bcopy( key, k_ipad, key_len);
bcopy( key, k_opad, key_len);

/* XOR key with ipad and opad values */
for (i=0; i<64; i++) {
k_ipad[i] ^= 0x36;
k_opad[i] ^= 0x5c;
}

primo · 11-12-2005, 01:48 PM

Man, you're implementing the HMAC algorithm wrong. You're not XORing the ipad with the key, nor the opad. Re-read the RFC. For the HMAC, it's better to have a key-setup function, an update function and a final function, just like MD5, SHA1, et al. OpenSSL has HMAC functions that perform what you're trying to code.
Check the manual:
http://www.freebsd.org/cgi/man.cgi?q...ts&format=html

jacques83 · 11-12-2005, 01:57 PM

well i am not quite able to understand how to use the HMAC functions given in openssl. i am using the code given in the rfc itself for implementing hmac

jacques83 · 11-12-2005, 02:00 PM

do you have any idea as to how to directly invoke those functions in the implementation of HMAC?i mean i am confused with the parameters that are passed to the init,update,final functions.any help will b most welcome.

thanks

Stenry · 04-11-2013, 05:17 AM

In freebsd,I have the same question.I solve them as below:
man 3 md5
search the lib of md5.h
It's lmd
so i add -lmd to LIBS in my Makefile

johnsfine · 04-11-2013, 07:23 AM

You might want to check the date on the question before providing an answer.