int Element_FromBytes(Element & e, int type, unsigned char *data)
{
string d = "";
if(is_base64((unsigned char) data[0])) {
string b64_encoded((char *) data);
d = _base64_decode(b64_encoded);
}
else {
return ELEMENT_INVALID_ARG;
}
if(type == ZR_t) {
bn_read_bin(e.zr.z, (unsigned char *) d.c_str(), d.size());
}
else if(type == G1_t) {
return g1_read_bin(e.g1.g, (unsigned char *) d.c_str(), d.size()); // x & y
}
else if(type == G2_t) {
return g2_read_bin(e.g2.g, (unsigned char *) d.c_str(), d.size()); // x1, y1 & x2, y2
}
else if(type == GT_t) {
return gt_read_bin(e.gt.g, (unsigned char *) d.c_str(), d.size()); // x1-6 && y1-6
}
return ELEMENT_INVALID_ARG;
}
/**
* \brief Decode Base64 encoded string to binary data
*
* Decode Base64 encoded string \p in to binary data \p out
*
* \param in Reference to a Base64 encoded string
* \param in_sz length of \p in in bytes (excluding the terminating \c NUL)
* \param out Pre-allocated buffer of size approx as \p in_sz
* \param out_sz Value-result argument initially containing the total
* size of \p out in bytes. On successful return it
* holds the decoded buffer size.
*
* \retval 0 on success
* \retval ~0 on failure
*/
int u_b64_decode (const char *in, size_t in_sz, uint8_t *out, size_t *out_sz)
{
char buf[4];
size_t i, len, pad, tot_sz = *out_sz;
uint8_t *pout;
dbg_return_if (in == NULL, ~0);
dbg_return_if (in_sz == 0, ~0);
dbg_return_if (out == NULL, ~0);
dbg_return_if (out_sz == NULL, ~0);
for (pout = out; in_sz; )
{
for (pad = 0, len = 0, i = 0; i < 4; ++i)
{
if (in_sz && in_sz-- > 0) /* Avoid wrapping around in_sz. */
{
buf[i] = *in++;
if (buf[i] == '=')
++pad;
else if (!is_base64(buf[i]))
return ~0;
++len;
}
else
buf[i] = '\0';
}
if (len)
{
size_t nlen = 3 - pad;
if (tot_sz >= nlen)
{
chunk_decode(buf, pout);
tot_sz -= nlen; /* Take care of subtracting pad bytes. */
pout += nlen;
}
else
return ~0; /* Not enough space. */
}
}
*out_sz -= tot_sz;
return 0;
}
/* See if we need to add the "Salted__" string to the front of the
* encrypted data.
*/
int
add_salted_str(fko_ctx_t ctx)
{
char *tbuf;
#if AFL_FUZZING
ctx->added_salted_str = 1;
return(FKO_SUCCESS);
#endif
/* We only add the base64 encoded salt to data that is already base64
* encoded
*/
if(is_base64((unsigned char *)ctx->encrypted_msg,
ctx->encrypted_msg_len) == 0)
return(FKO_ERROR_INVALID_DATA_ENCODE_NOTBASE64);
if(constant_runtime_cmp(ctx->encrypted_msg,
B64_RIJNDAEL_SALT, B64_RIJNDAEL_SALT_STR_LEN) != 0)
{
/* We need to realloc space for the salt.
*/
tbuf = realloc(ctx->encrypted_msg, ctx->encrypted_msg_len
+ B64_RIJNDAEL_SALT_STR_LEN+1);
if(tbuf == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
memmove(tbuf+B64_RIJNDAEL_SALT_STR_LEN, tbuf, ctx->encrypted_msg_len);
//Ìí¼ÓÑΡ£
ctx->encrypted_msg = memcpy(tbuf,
B64_RIJNDAEL_SALT, B64_RIJNDAEL_SALT_STR_LEN);
/* Adjust the encoded msg len for added SALT value and Make sure we
* are still a properly NULL-terminated string (Ubuntu was one system
* for which this was an issue).
*/
ctx->encrypted_msg_len += B64_RIJNDAEL_SALT_STR_LEN;
tbuf[ctx->encrypted_msg_len] = '\0';
ctx->added_salted_str = 1;
}
return(FKO_SUCCESS);
}
/**
* Count the number of valid base64 characters in the supplied input
* buffer.
* @desc this function counts the number of valid base64 characters,
* skipping CR and LF characters. Invalid characters are treated as
* end of buffer markers.
*
* \param inbuff the buffer to check.
* \param inputlen the length of the input buffer.
* \return the number of valid base64 characters.
*/
static uint32_t get_num_valid_characters( const uint8_t* inbuff,
size_t inputlen )
{
uint32_t validCharCount=0;
uint32_t idx=0;
while ( idx < inputlen )
{
if ( is_base64( inbuff[idx] ) )
{
++validCharCount;
++idx;
}
else if ( inbuff[idx] == '\r' || inbuff[idx] == '\n' )
{
++idx;
}
else
{
break;
}
}
return validCharCount;
}
/* Validate and in some cases preprocess/reformat the SPA data. Return an
* error code value if there is any indication the data is not valid spa data.
*/
static int
preprocess_spa_data(const fko_srv_options_t *opts, spa_pkt_info_t *spa_pkt)
{
char *ndx = (char *)&(spa_pkt->packet_data);
int i, pkt_data_len = 0;
pkt_data_len = spa_pkt->packet_data_len;
/* At this point, we can reset the packet data length to 0. This is our
* indicator to the rest of the program that we do not have a current
* spa packet to process (after this one that is).
*/
spa_pkt->packet_data_len = 0;
/* These two checks are already done in process_packet(), but this is a
* defensive measure to run them again here
*/
if(pkt_data_len < MIN_SPA_DATA_SIZE)
return(SPA_MSG_BAD_DATA);
if(pkt_data_len > MAX_SPA_PACKET_LEN)
return(SPA_MSG_BAD_DATA);
/* Ignore any SPA packets that contain the Rijndael or GnuPG prefixes
* since an attacker might have tacked them on to a previously seen
* SPA packet in an attempt to get past the replay check. And, we're
* no worse off since a legitimate SPA packet that happens to include
* a prefix after the outer one is stripped off won't decrypt properly
* anyway because libfko would not add a new one.
*/
if(constant_runtime_cmp(ndx, B64_RIJNDAEL_SALT, B64_RIJNDAEL_SALT_STR_LEN) == 0)
return(SPA_MSG_BAD_DATA);
if(pkt_data_len > MIN_GNUPG_MSG_SIZE
&& constant_runtime_cmp(ndx, B64_GPG_PREFIX, B64_GPG_PREFIX_STR_LEN) == 0)
return(SPA_MSG_BAD_DATA);
/* Detect and parse out SPA data from an HTTP request. If the SPA data
* starts with "GET /" and the user agent starts with "Fwknop", then
* assume it is a SPA over HTTP request.
*/
if(strncasecmp(opts->config[CONF_ENABLE_SPA_OVER_HTTP], "Y", 1) == 0
&& strncasecmp(ndx, "GET /", 5) == 0
&& strstr(ndx, "User-Agent: Fwknop") != NULL)
{
/* This looks like an HTTP request, so let's see if we are
* configured to accept such request and if so, find the SPA
* data.
*/
/* Now extract, adjust (convert characters translated by the fwknop
* client), and reset the SPA message itself.
*/
strlcpy((char *)spa_pkt->packet_data, ndx+5, pkt_data_len);
pkt_data_len -= 5;
for(i=0; i<pkt_data_len; i++)
{
if(isspace(*ndx)) /* The first space marks the end of the req */
{
*ndx = '\0';
break;
}
else if(*ndx == '-') /* Convert '-' to '+' */
*ndx = '+';
else if(*ndx == '_') /* Convert '_' to '/' */
*ndx = '/';
ndx++;
}
if(i < MIN_SPA_DATA_SIZE)
return(SPA_MSG_BAD_DATA);
spa_pkt->packet_data_len = pkt_data_len = i;
}
/* Require base64-encoded data
*/
if(! is_base64(spa_pkt->packet_data, pkt_data_len))
return(SPA_MSG_NOT_SPA_DATA);
/* If we made it here, we have no reason to assume this is not SPA data.
* The ultimate test will be whether the SPA data authenticates via an
* HMAC anyway.
*/
return(FKO_SUCCESS);
}
int Element_FromBytes(Element &e, int type, unsigned char *data)
{
if(type == ZR_t) {
if(is_base64((unsigned char) data[0])) {
string b64_encoded((char *) data);
string s = _base64_decode(b64_encoded);
int cnt = 0;
Big b = Big(bytesToBig(s, &cnt));
e = Element(b);
// cout << "Element_FromBytes: " << e << endl;
return TRUE;
}
}
else if(type == G1_t) {
if(is_base64((unsigned char) data[0])) {
string b64_encoded((char *) data);
string s = _base64_decode(b64_encoded);
int cnt = 0;
Big x, y;
x = bytesToBig(s, &cnt);
s = s.substr(cnt);
y = bytesToBig(s, &cnt);
// cout << "point => (" << x << ", " << y << ")" << endl;
G1 p;
p.g.set(x, y);
e = Element(p);
//cout << "Element_FromBytes: " << e << endl;
return TRUE;
}
}
#if ASYMMETRIC == 1
else if(type == G2_t) {
if(is_base64((unsigned char) data[0])) {
string b64_encoded((char *) data);
string s = _base64_decode(b64_encoded);
// cout << "original => " << s << endl;
int cnt = 0;
G2 p;
#if BUILD_MNT_CURVE == 1
ZZn a[MNT_G2_SIZE];
for(int i = 0; i < MNT_G2_SIZE; i++) {
Big b = bytesToBig(s, &cnt);
a[i] = ZZn( b ); // retrieve all six coordinates
s = s.substr(cnt);
}
ZZn3 x (a[0], a[1], a[2]);
ZZn3 y (a[3], a[4], a[5]);
p.g.set(x, y);
#elif BUILD_BN_CURVE == 1
Big a[BN_G2_SIZE];
for(int i = 0; i < BN_G2_SIZE; i++) {
a[i] = bytesToBig(s, &cnt);
s = s.substr(cnt); // advance s ptr
}
ZZn2 x1(a[0], a[1]); // each zzn2 has a (x, y) coordinate of type Big
ZZn2 y1(a[2], a[3]);
p.g.set(x1, y1);
#endif
e = Element(p);
//cout << "Element_FromBytes: " << e << endl;
return TRUE;
}
}
#endif
else if(type == GT_t) {
if(is_base64((unsigned char) data[0])) {
string b64_encoded((char *) data);
string s = _base64_decode(b64_encoded);
// cout << "original => " << s << endl;
int cnt = 0;
GT p;
#if BUILD_MNT_CURVE == 1
Big a[MNT_GT_SIZE];
for(int i = 0; i < MNT_GT_SIZE; i++) {
a[i] = bytesToBig(s, &cnt);
s = s.substr(cnt); // advance s ptr
}
ZZn2 x, y, z;
x.set(a[0], a[1]);
y.set(a[2], a[3]);
z.set(a[4], a[5]);
p.g.set(x, y, z);
#elif BUILD_BN_CURVE == 1
Big a[BN_GT_SIZE];
for(int i = 0; i < BN_GT_SIZE; i++) {
a[i] = bytesToBig(s, &cnt);
s = s.substr(cnt); // advance s ptr
}
ZZn2 x0, x1, y0, y1, z0, z1;
x0.set(a[0], a[1]);
x1.set(a[2], a[3]);
y0.set(a[4], a[5]);
y1.set(a[6], a[7]);
z0.set(a[8], a[9]);
z1.set(a[10], a[11]);
ZZn4 x(x0, x1);
ZZn4 y(y0, y1);
ZZn4 z(z0, z1);
p.g.set(x, y, z);
#elif BUILD_SS_CURVE == 1
// must be symmetric
Big a[SS_GT_SIZE];
for(int i = 0; i < SS_GT_SIZE; i++) {
a[i] = bytesToBig(s, &cnt);
s = s.substr(cnt); // advance s ptr
}
p.g.set(a[0], a[1]);
#endif
e = Element(p);
//cout << "Element_FromBytes: " << e << endl;
return TRUE;
}
}
return 0;
}
