HTTP: The Definitive Guide

Reference Code

The following code implements the calculations of H(A1), H(A2), request-digest, and response-digest, from RFC 2617. It uses the MD5 implementation from RFC 1321.

File “digcalc.h”

#define HASHLEN 16
typedef char HASH[HASHLEN];
#define HASHHEXLEN 32
typedef char HASHHEX[HASHHEXLEN+1];
#define IN
#define OUT
/* calculate H(A1) as per HTTP Digest spec */
void DigestCalcHA1(
    IN char * pszAlg,
    IN char * pszUserName,
    IN char * pszRealm,
    IN char * pszPassword,
    IN char * pszNonce,
    IN char * pszCNonce,
    OUT HASHHEX SessionKey
    );

/* calculate request-digest/response-digest as per HTTP Digest spec */
void DigestCalcResponse(
    IN HASHHEX HA1,           /* H(A1) */
    IN char * pszNonce,       /* nonce from server */
    IN char * pszNonceCount,  /* 8 hex digits */
    IN char * pszCNonce,      /* client nonce */
    IN char * pszQop,         /* qop-value: "", "auth", "auth-int" */
    IN char * pszMethod,      /* method from the request */
    IN char * pszDigestUri,   /* requested URL */
    IN HASHHEX HEntity,       /* H(entity body) if qop="auth-int" */
    OUT HASHHEX Response      /* request-digest or response-digest */
    );

File “digcalc.c”

#include <global.h> #include <md5.h> #include <string.h> #include "digcalc.h" void CvtHex( IN HASH Bin, OUT HASHHEX Hex ) { unsigned short i; unsigned char j; for (i = 0; i < HASHLEN; i++) { j = (Bin[i] >> 4) & 0xf; if (j <= 9) Hex[i*2] = (j + '0'); else Hex[i*2] = (j + 'a' - 10); j = Bin[i] & 0xf; if (j <= 9) Hex[i*2+1] = (j + '0'); else Hex[i*2+1] = (j + 'a' - 10); }; Hex[HASHHEXLEN] = '\0'; }; /* calculate H(A1) as ...