#include "md5.hpp"
#include <cstring>
#include "../compat/rawmem.hpp"
#include "../strings/xstring.hpp"
#include "../strings/vstring.hpp"
#include "random.hpp"
#include "../poison.hpp"
// auxilary data
/*
sin() constant table
#Reformatted output of:
echo 'scale=40; obase=16; for (i=1;i<=64;i++) print 2^32 * sin(i), "\n"' |
bc | sed 's/^-//;s/^/0x/;s/\..*$/,/'
*/
static
const uint32_t T[64] =
{
// used by round 1
0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, //0
0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501, //4
0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be, //8
0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821, //12
// used by round 2
0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa, //16
0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8, //20
0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed, //24
0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a, //28
// used by round 3
0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c, //32
0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70, //36
0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05, //40
0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665, //44
// used by round 4
0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039, //48
0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1, //52
0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1, //56
0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391, //60
};
// auxilary functions
// note - the RFC defines these by non-CS conventions: or=v, and=(empty)
static
uint32_t rotate_left(uint32_t val, unsigned shift)
{
return val << shift | val >> (32 - shift);
}
static
uint32_t F(uint32_t X, uint32_t Y, uint32_t Z)
{
return (X & Y) | (~X & Z);
}
static
uint32_t G(uint32_t X, uint32_t Y, uint32_t Z)
{
return (X & Z) | (Y & ~Z);
}
static
uint32_t H(uint32_t X, uint32_t Y, uint32_t Z)
{
return X ^ Y ^ Z;
}
static
uint32_t I(uint32_t X, uint32_t Y, uint32_t Z)
{
return Y ^ (X | ~Z);
}
static
const struct
{
uint8_t k : 4;
uint8_t : 0;
uint8_t s : 5;
// uint8_t i : 6; just increments constantly, from 1 .. 64 over all rounds
}
MD5_round1[16] =
{
{ 0, 7}, { 1, 12}, { 2, 17}, { 3, 22},
{ 4, 7}, { 5, 12}, { 6, 17}, { 7, 22},
{ 8, 7}, { 9, 12}, {10, 17}, {11, 22},
{12, 7}, {13, 12}, {14, 17}, {15, 22},
},
MD5_round2[16] =
{
{ 1, 5}, { 6, 9}, {11, 14}, { 0, 20},
{ 5, 5}, {10, 9}, {15, 14}, { 4, 20},
{ 9, 5}, {14, 9}, { 3, 14}, { 8, 20},
{13, 5}, { 2, 9}, { 7, 14}, {12, 20},
},
MD5_round3[16] =
{
{ 5, 4}, { 8, 11}, {11, 16}, {14, 23},
{ 1, 4}, { 4, 11}, { 7, 16}, {10, 23},
{13, 4}, { 0, 11}, { 3, 16}, { 6, 23},
{ 9, 4}, {12, 11}, {15, 16}, { 2, 23},
},
MD5_round4[16] =
{
{ 0, 6}, { 7, 10}, {14, 15}, { 5, 21},
{12, 6}, { 3, 10}, {10, 15}, { 1, 21},
{ 8, 6}, {15, 10}, { 6, 15}, {13, 21},
{ 4, 6}, {11, 10}, { 2, 15}, { 9, 21},
};
void MD5_init(MD5_state* state)
{
// in the RFC, these are specified as bytes, interpreted as little-endian
state->val[0] = 0x67452301;
state->val[1] = 0xEFCDAB89;
state->val[2] = 0x98BADCFE;
state->val[3] = 0x10325476;
}
#define X block.data
void MD5_do_block(MD5_state* state, MD5_block block)
{
#define a state->val[(16 - i) % 4]
#define b state->val[(17 - i) % 4]
#define c state->val[(18 - i) % 4]
#define d state->val[(19 - i) % 4]
// save the values
const MD5_state saved = *state;
// round 1
for (int i = 0; i < 16; i++)
{
#define k MD5_round1[i].k
#define s MD5_round1[i].s
a = b + rotate_left(a + F(b, c, d) + X[k] + T[i + 0x0], s);
#undef k
#undef s
}
// round 2
for (int i = 0; i < 16; i++)
{
#define k MD5_round2[i].k
#define s MD5_round2[i].s
a = b + rotate_left(a + G(b, c, d) + X[k] + T[i + 0x10], s);
#undef k
#undef s
}
// round 3
for (int i = 0; i < 16; i++)
{
#define k MD5_round3[i].k
#define s MD5_round3[i].s
a = b + rotate_left(a + H(b, c, d) + X[k] + T[i + 0x20], s);
#undef k
#undef s
}
// round 4
for (int i = 0; i < 16; i++)
{
#define k MD5_round4[i].k
#define s MD5_round4[i].s
a = b + rotate_left(a + I(b, c, d) + X[k] + T[i + 0x30], s);
#undef k
#undef s
}
// adjust state based on original
state->val[0] += saved.val[0];
state->val[1] += saved.val[1];
state->val[2] += saved.val[2];
state->val[3] += saved.val[3];
#undef a
#undef b
#undef c
#undef d
}
void MD5_to_bin(MD5_state state, md5_binary& out)
{
for (int i = 0; i < 0x10; i++)
out[i] = state.val[i / 4] >> 8 * (i % 4);
}
static
const char hex[] = "0123456789abcdef";
void MD5_to_str(MD5_state state, md5_string& out_)
{
md5_binary bin;
MD5_to_bin(state, bin);
char out[0x20];
for (int i = 0; i < 0x10; i++)
out[2 * i] = hex[bin[i] >> 4],
out[2 * i + 1] = hex[bin[i] & 0xf];
out_ = stringish<md5_string>(XString(out, out + 0x20, nullptr));
}
MD5_state MD5_from_string(XString msg)
{
MD5_state state;
MD5_init(&state);
MD5_block block;
const uint64_t msg_full_len = msg.size();
while (msg.size() >= 64)
{
for (int i = 0; i < 0x10; i++)
X[i] = msg[4 * i + 0] | msg[4 * i + 1] << 8 | msg[4 * i + 2] << 16 | msg[4 * i + 3] << 24;
MD5_do_block(&state, block);
msg = msg.xslice_t(64);
}
// now pad 1-512 bits + the 64-bit length - may be two blocks
uint8_t buf[0x40] = {};
really_memcpy(buf, reinterpret_cast<const uint8_t *>(msg.data()), msg.size());
buf[msg.size()] = 0x80; // a single one bit
if (64 - msg.size() > 8)
{
for (int i = 0; i < 8; i++)
buf[0x38 + i] = (msg_full_len * 8) >> (i * 8);
}
for (int i = 0; i < 0x10; i++)
X[i] = buf[4 * i + 0] | buf[4 * i + 1] << 8 | buf[4 * i + 2] << 16 | buf[4 * i + 3] << 24;
MD5_do_block(&state, block);
if (64 - msg.size() <= 8)
{
really_memset0(buf, 0x38);
for (int i = 0; i < 8; i++)
buf[0x38 + i] = (msg_full_len * 8) >> (i * 8);
for (int i = 0; i < 0x10; i++)
X[i] = buf[4 * i + 0] | buf[4 * i + 1] << 8 | buf[4 * i + 2] << 16 | buf[4 * i + 3] << 24;
MD5_do_block(&state, block);
}
return state;
}
