extern_md5.c

KphoneSI (kpsi) is a SIP (Session Initiation Protocol) user agent for Linux, with which you can in

#include <sys/types.h>
#include <openssl/md5.h>
#include <stdlib.h>
#include <string.h>

#include "extern_md5.h"
#include "base64.h"


void CvtHex( HASH, HASHHEX );

void DigestCalcHA1(
	const char * pszAlg,
	const char * pszUserName,
	const char * pszRealm,
	const char * pszPassword,
	const char * pszNonce,
	const char * pszCNonce,
	HASHHEX SessionKey
);

void DigestCalcResponse(
	HASHHEX HA1,
	const char * pszNonce,
	const char * pszNonceCount,
	const char * pszCNonce,
	const char * pszQop,
	const char * pszMethod,
	const char * pszDigestUri,
	HASHHEX HEntity,
	HASHHEX Response
);

/*------------------------------------*/


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 per spec */
void DigestCalcHA1(
	IN const char * pszAlg,
	IN const char * pszUserName,
	IN const char * pszRealm,
	IN const char * pszPassword,
	IN const char * pszNonce,
	IN const char * pszCNonce,
	OUT HASHHEX SessionKey )
{
	MD5_CTX Md5Ctx;
	HASH HA1;

	MD5_Init( &Md5Ctx );
	MD5_Update( &Md5Ctx, pszUserName, strlen( pszUserName ) );
	MD5_Update( &Md5Ctx, ":", 1 );
	MD5_Update( &Md5Ctx, pszRealm, strlen( pszRealm ) );
	MD5_Update( &Md5Ctx, ":", 1 );
	MD5_Update( &Md5Ctx, pszPassword, strlen( pszPassword ) );
	MD5_Final( HA1, &Md5Ctx );
	if( strcmp( pszAlg, "md5-sess" ) == 0 ) {
		MD5_Init( &Md5Ctx );
		MD5_Update( &Md5Ctx, HA1, HASHLEN );
		MD5_Update( &Md5Ctx, ":", 1 );
		MD5_Update( &Md5Ctx, pszNonce, strlen( pszNonce ) );
		MD5_Update( &Md5Ctx, ":", 1 );
		MD5_Update( &Md5Ctx, pszCNonce, strlen( pszCNonce ) );
		MD5_Final( HA1, &Md5Ctx );
	}
	CvtHex( HA1, SessionKey );
}

/* calculate request-digest/response-digest as per HTTP Digest spec */
void DigestCalcResponse(
	IN HASHHEX HA1,                 /* H(A1) */
	IN const char * pszNonce,       /* nonce from server */
	IN const char * pszNonceCount,  /* 8 hex digits */
	IN const char * pszCNonce,      /* client nonce */
	IN const char * pszQop,         /* qop-value: "", "auth", "auth-int" */
	IN const char * pszMethod,      /* method from the request */
	IN const char * pszDigestUri,   /* requested URL */
	IN HASHHEX HEntity,             /* H(entity body) if qop="auth-int" */
	OUT HASHHEX Response )          /* request-digest or response-digest */
{
	MD5_CTX Md5Ctx;
	HASH HA2;
	HASH RespHash;
	HASHHEX HA2Hex;

	/* calculate H(A2) */
	MD5_Init( &Md5Ctx );
	MD5_Update( &Md5Ctx, pszMethod, strlen( pszMethod ) );
	MD5_Update( &Md5Ctx, ":", 1 );
	MD5_Update( &Md5Ctx, pszDigestUri, strlen( pszDigestUri ) );
	if( strcmp( pszQop, "auth-int") == 0 ) {
		MD5_Update( &Md5Ctx, ":", 1 );
		MD5_Update( &Md5Ctx, HEntity, HASHHEXLEN );
	};
	MD5_Final( HA2, &Md5Ctx );
	CvtHex( HA2, HA2Hex );

	/* calculate response */
	MD5_Init( &Md5Ctx );
	MD5_Update( &Md5Ctx, HA1, HASHHEXLEN );
	MD5_Update( &Md5Ctx, ":", 1 );
	MD5_Update( &Md5Ctx, pszNonce, strlen( pszNonce ) );
	MD5_Update( &Md5Ctx, ":", 1 );
	if( *pszQop ) {
		MD5_Update( &Md5Ctx, pszNonceCount, strlen( pszNonceCount ) );
		MD5_Update( &Md5Ctx, ":", 1 );
		MD5_Update( &Md5Ctx, pszCNonce, strlen( pszCNonce ) );
		MD5_Update( &Md5Ctx, ":", 1 );
		MD5_Update( &Md5Ctx, pszQop, strlen( pszQop ) );
		MD5_Update( &Md5Ctx, ":", 1 );
	};
	MD5_Update( &Md5Ctx, HA2Hex, HASHHEXLEN );
	MD5_Final( RespHash, &Md5Ctx );
	CvtHex( RespHash, Response );
}