void rc6DecryptBlock(Rc6Context *context, const uint8_t *input, uint8_t *output)
{
uint_t i;
uint32_t t;
uint32_t u;
//Load the 4 working registers with the ciphertext
uint32_t a = LOAD32LE(input + 0);
uint32_t b = LOAD32LE(input + 4);
uint32_t c = LOAD32LE(input + 8);
uint32_t d = LOAD32LE(input + 12);
//First, update C and A
c -= context->s[2 * RC6_NB_ROUNDS + 3];
a -= context->s[2 * RC6_NB_ROUNDS + 2];
//Apply 20 rounds
for(i = RC6_NB_ROUNDS; i > 0; i--)
{
t = d;
d = c;
c = b;
b = a;
a = t;
u = (d * (2 * d + 1));
u = ROL32(u, 5);
t = (b * (2 * b + 1));
t = ROL32(t, 5);
c -= context->s[2 * i + 1];
c = ROR32(c, t % 32) ^ u;
a -= context->s[2 * i];
a = ROR32(a, u % 32) ^ t;
}
//Update D and B
d -= context->s[1];
b -= context->s[0];
//The resulting value is the plaintext
STORE32LE(a, output + 0);
STORE32LE(b, output + 4);
STORE32LE(c, output + 8);
STORE32LE(d, output + 12);
}
void rc6EncryptBlock(Rc6Context *context, const uint8_t *input, uint8_t *output)
{
uint_t i;
uint32_t t;
uint32_t u;
//Load the 4 working registers with the plaintext
uint32_t a = LOAD32LE(input + 0);
uint32_t b = LOAD32LE(input + 4);
uint32_t c = LOAD32LE(input + 8);
uint32_t d = LOAD32LE(input + 12);
//First, update B and D
b += context->s[0];
d += context->s[1];
//Apply 20 rounds
for(i = 1; i <= RC6_NB_ROUNDS; i++)
{
t = (b * (2 * b + 1));
t = ROL32(t, 5);
u = (d * (2 * d + 1));
u = ROL32(u, 5);
a ^= t;
a = ROL32(a, u % 32) + context->s[2 * i];
c ^= u;
c = ROL32(c, t % 32) + context->s[2 * i + 1];
t = a;
a = b;
b = c;
c = d;
d = t;
}
//Update A and C
a += context->s[2 * RC6_NB_ROUNDS + 2];
c += context->s[2 * RC6_NB_ROUNDS + 3];
//The resulting value is the ciphertext
STORE32LE(a, output + 0);
STORE32LE(b, output + 4);
STORE32LE(c, output + 8);
STORE32LE(d, output + 12);
}
size_t vsscan9p1 (uint8_t *msg, char fmt, void *p) {
size_t l;
switch (fmt) {
case '0':
*(uint8_t *)p = msg[0];
return 1;
case '1':
LOAD16LE(*(uint16_t *)p, msg);
return 2;
case '2':
LOAD32LE(*(uint32_t *)p, msg);
return 4;
case '3':
LOAD64LE(*(uint64_t *)p, msg);
return 8;
case 'd':
return loadDir (p, msg);
case 'q':
return loadQid (p, msg);
case 's':
LOAD16LE(l, msg);
*(char **)p = xstrndup (msg + 2, l);
return (2 + l);
}
}
static NOINLINE int Read32(tiff* p)
{
int v;
if (p->BigEndian)
v = LOAD32BE(p->Ptr);
else
v = LOAD32LE(p->Ptr);
p->Ptr += 4;
return v;
}
ssize_t write9pmsg (int fd, uint8_t *msg) {
size_t size;
LOAD32LE(size, msg);
switch (msg[4] /* type */) {
case RRead:
if (write (fd, msg, 11) < 11) return (-1);
return 11;
case TWrite:
if (write (fd, msg, 23) < 23) return (-1);
return 23;
default:
if (write (fd, msg, size) < size) return (-1);
return size;
}
}
ssize_t read9pmsg (int fd, uint8_t *msg, size_t n) {
ssize_t m, size;
if (n < 7) return (-1);
m = read (fd, msg, 7);
if (m == 0) return 0;
if (m < 0) return (-1);
LOAD32LE(size, msg);
if (size < 7) return (-1);
switch (msg[4] /* type */) {
// Special case for TWrite and RRead, lest we copy huge data
case RRead:
if (n < 11 || read (fd, msg + 7, 4) < 4) return (-1);
return 11;
case TWrite:
if (n < 24 || read (fd, msg + 7, 16) < 16) return (-1);
return 23;
default:
if (n < size) return (-1);
if (read (fd, msg + 7, size - 7) + 7 < size) return (-1);
return size;
}
}
size_t loadQid (Qid *p_qid, uint8_t *msg) {
p_qid -> type = msg[0];
LOAD32LE(p_qid -> vers, msg + 1);
LOAD64LE(p_qid -> path, msg + 5);
return 13;
}
