/**
* @brief Calculate the MD5 hash of a string.
*
* Example: "%{md5:foo}" == "acbd18db4cc2f85cedef654fccc4a4d8"
*/
static size_t xlat_md5(UNUSED void *instance, REQUEST *request,
char *fmt, char *out, size_t outlen,
UNUSED RADIUS_ESCAPE_STRING func)
{
int i;
uint8_t digest[16];
FR_MD5_CTX ctx;
char buffer[1024];
if (!radius_xlat(buffer, sizeof(buffer), fmt, request, func)) {
*out = '\0';
return 0;
}
fr_MD5Init(&ctx);
fr_MD5Update(&ctx, (void *) buffer, strlen(buffer));
fr_MD5Final(digest, &ctx);
if (outlen < 33) {
snprintf(out, outlen, "md5_overflow");
return strlen(out);
}
for (i = 0; i < 16; i++) {
snprintf(out + i * 2, 3, "%02x", digest[i]);
}
return strlen(out);
}
/**
* @brief Calculate the MD5 hash of a string.
*
* Example: "%{md5:foo}" == "acbd18db4cc2f85cedef654fccc4a4d8"
*/
static size_t md5_xlat(UNUSED void *instance, UNUSED REQUEST *request,
char const *fmt, char *out, size_t outlen)
{
uint8_t digest[16];
int i, len;
FR_MD5_CTX ctx;
/*
* We need room for at least one octet of output.
*/
if (outlen < 3) {
*out = '\0';
return 0;
}
fr_MD5Init(&ctx);
fr_MD5Update(&ctx, (const void *) fmt, strlen(fmt));
fr_MD5Final(digest, &ctx);
/*
* Each digest octet takes two hex digits, plus one for
* the terminating NUL.
*/
len = (outlen / 2) - 1;
if (len > 16) len = 16;
for (i = 0; i < len; i++) {
snprintf(out + i * 2, 3, "%02x", digest[i]);
}
return strlen(out);
}
static void calc_md5_digest(uint8_t *buffer, uint8_t const *challenge, size_t challen, char const *password)
{
uint8_t buf[1024];
int i;
FR_MD5_CTX context;
memset(buf, 0, 1024);
memset(buf, 0x36, 64);
for(i=0; i<64 && password[i]; i++) buf[i]^=password[i];
memcpy(buf+64, challenge, challen);
fr_MD5Init(&context);
fr_MD5Update(&context, buf, 64+challen);
memset(buf, 0x5c, 64);
for(i=0; i<64 && password[i]; i++) buf[i]^=password[i];
fr_MD5Final(buf+64,&context);
fr_MD5Init(&context);
fr_MD5Update(&context,buf,64+16);
fr_MD5Final(buffer,&context);
}
static void calc_apop_digest(uint8_t *buffer, uint8_t const *challenge,
size_t challen, char const *password)
{
FR_MD5_CTX context;
fr_MD5Init(&context);
fr_MD5Update(&context, challenge, challen);
fr_MD5Update(&context, (uint8_t const *) password, strlen(password));
fr_MD5Final(buffer, &context);
}
static int respond_eap_md5(RADIUS_PACKET *req,
RADIUS_PACKET *rep)
{
VALUE_PAIR *vp, *id, *state;
size_t valuesize;
uint8_t identifier;
uint8_t const *value;
FR_MD5_CTX context;
uint8_t response[16];
cleanresp(rep);
if ((state = paircopy2(NULL, req->vps, PW_STATE, 0, TAG_ANY)) == NULL)
{
fprintf(stderr, "radeapclient: no state attribute found\n");
return 0;
}
if ((id = paircopy2(NULL, req->vps, ATTRIBUTE_EAP_ID, 0, TAG_ANY)) == NULL)
{
fprintf(stderr, "radeapclient: no EAP-ID attribute found\n");
return 0;
}
identifier = id->vp_integer;
if ((vp = pairfind(req->vps, ATTRIBUTE_EAP_BASE+PW_EAP_MD5, 0, TAG_ANY)) == NULL)
{
fprintf(stderr, "radeapclient: no EAP-MD5 attribute found\n");
return 0;
}
/* got the details of the MD5 challenge */
valuesize = vp->vp_octets[0];
value = &vp->vp_octets[1];
/* sanitize items */
if(valuesize > vp->length)
{
fprintf(stderr, "radeapclient: md5 valuesize if too big (%u > %u)\n",
(unsigned int) valuesize, (unsigned int) vp->length);
return 0;
}
/* now do the CHAP operation ourself, rather than build the
* buffer. We could also call rad_chap_encode, but it wants
* a CHAP-Challenge, which we don't want to bother with.
*/
fr_MD5Init(&context);
fr_MD5Update(&context, &identifier, 1);
fr_MD5Update(&context, (uint8_t *) password, strlen(password));
fr_MD5Update(&context, value, valuesize);
fr_MD5Final(response, &context);
{
uint8_t *p;
uint8_t lg_response;
vp = paircreate(rep, ATTRIBUTE_EAP_BASE+PW_EAP_MD5, 0);
vp->length = 17;
p = talloc_zero_array(vp, uint8_t, 17);
lg_response = 16;
memcpy(p, &lg_response, 1);
memcpy(p + 1, response, 16);
pairmemsteal(vp, p);
}
pairreplace(&(rep->vps), vp);
pairreplace(&(rep->vps), id);
/* copy the state object in */
pairreplace(&(rep->vps), state);
return 1;
}
void
fr_hmac_md5(const uint8_t *text, int text_len,
const uint8_t *key, int key_len,
uint8_t *digest)
{
FR_MD5_CTX context;
uint8_t k_ipad[65]; /* inner padding -
* key XORd with ipad
*/
uint8_t k_opad[65]; /* outer padding -
* key XORd with opad
*/
uint8_t tk[16];
int i;
/* if key is longer than 64 bytes reset it to key=MD5(key) */
if (key_len > 64) {
FR_MD5_CTX tctx;
fr_MD5Init(&tctx);
fr_MD5Update(&tctx, key, key_len);
fr_MD5Final(tk, &tctx);
key = tk;
key_len = 16;
}
/*
* the HMAC_MD5 transform looks like:
*
* MD5(K XOR opad, MD5(K XOR ipad, text))
*
* where K is an n byte key
* ipad is the byte 0x36 repeated 64 times
* opad is the byte 0x5c repeated 64 times
* and text is the data being protected
*/
/* start out by storing key in pads */
memset( k_ipad, 0, sizeof(k_ipad));
memset( k_opad, 0, sizeof(k_opad));
memcpy( k_ipad, key, key_len);
memcpy( k_opad, key, key_len);
/* XOR key with ipad and opad values */
for (i = 0; i < 64; i++) {
k_ipad[i] ^= 0x36;
k_opad[i] ^= 0x5c;
}
/*
* perform inner MD5
*/
fr_MD5Init(&context); /* init context for 1st
* pass */
fr_MD5Update(&context, k_ipad, 64); /* start with inner pad */
fr_MD5Update(&context, text, text_len); /* then text of datagram */
fr_MD5Final(digest, &context); /* finish up 1st pass */
/*
* perform outer MD5
*/
fr_MD5Init(&context); /* init context for 2nd
* pass */
fr_MD5Update(&context, k_opad, 64); /* start with outer pad */
fr_MD5Update(&context, digest, 16); /* then results of 1st
* hash */
fr_MD5Final(digest, &context); /* finish up 2nd pass */
}
static int
respond_eap_md5(RADIUS_PACKET *req,
RADIUS_PACKET *rep,const char* pwd)
{
VALUE_PAIR *vp, *id, *state;
size_t valuesize;
uint8_t identifier;
uint8_t *value;
FR_MD5_CTX context;
uint8_t response[16];
cleanresp(rep);
if ((state = paircopy2(req->vps, PW_STATE)) == NULL)
{
fr_strerror_printf("radeapclient: no state attribute found");
return 0;
}
if ((id = paircopy2(req->vps, ATTRIBUTE_EAP_ID)) == NULL)
{
fr_strerror_printf("radeapclient: no EAP-ID attribute found");
return 0;
}
identifier = id->vp_integer;
if ((vp = pairfind(req->vps, ATTRIBUTE_EAP_BASE+PW_EAP_MD5)) == NULL)
{
fr_strerror_printf("radeapclient: no EAP-MD5 attribute found");
return 0;
}
/* got the details of the MD5 challenge */
valuesize = vp->vp_octets[0];
value = &vp->vp_octets[1];
/* sanitize items */
if(valuesize > vp->length)
{
fr_strerror_printf("radeapclient: md5 valuesize if too big (%u > %u)\n",
(unsigned int) valuesize, (unsigned int) vp->length);
return 0;
}
/* now do the CHAP operation ourself, rather than build the
* buffer. We could also call rad_chap_encode, but it wants
* a CHAP-Challenge, which we don't want to bother with.
*/
fr_MD5Init(&context);
fr_MD5Update(&context, &identifier, 1);
fr_MD5Update(&context, (uint8_t *) pwd, strlen(pwd));
fr_MD5Update(&context, value, valuesize);
fr_MD5Final(response, &context);
vp = paircreate(ATTRIBUTE_EAP_BASE+PW_EAP_MD5, PW_TYPE_OCTETS);
vp->vp_octets[0]=16;
memcpy(&vp->vp_strvalue[1], response, 16);
vp->length = 17;
pairreplace(&(rep->vps), vp);
pairreplace(&(rep->vps), id);
/* copy the state object in */
pairreplace(&(rep->vps), state);
return 1;
}
