Made Base64 decoding constant-time (with regards to actual data byte contents).

This commit is contained in:
Thomas Pornin 2018-08-06 00:16:09 +02:00
parent d8fa415fca
commit ffe3c9166b
2 changed files with 83 additions and 64 deletions

View file

@ -122,59 +122,52 @@ static const unsigned char t0_codeblock[] = {
0x14, 0x2C, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x03, 0x13, 0x04, 0x76, 0x01,
0x2D, 0x0C, 0x06, 0x05, 0x2E, 0x01, 0x03, 0x2D, 0x00, 0x01, 0x0D, 0x27,
0x05, 0x04, 0x01, 0x03, 0x2D, 0x00, 0x15, 0x2E, 0x01, 0x02, 0x2D, 0x00,
0x01, 0x01, 0x7F, 0x03, 0x00, 0x24, 0x01, 0x00, 0x17, 0x0D, 0x06, 0x03,
0x13, 0x04, 0x3C, 0x01, 0x7F, 0x17, 0x0D, 0x06, 0x13, 0x13, 0x02, 0x00,
0x05, 0x06, 0x2E, 0x01, 0x03, 0x2D, 0x04, 0x03, 0x01, 0x7F, 0x22, 0x01,
0x00, 0x00, 0x04, 0x23, 0x01, 0x01, 0x17, 0x0D, 0x06, 0x09, 0x13, 0x01,
0x00, 0x22, 0x01, 0x00, 0x00, 0x04, 0x14, 0x01, 0x02, 0x17, 0x0D, 0x06,
0x01, 0x01, 0x7F, 0x03, 0x00, 0x25, 0x01, 0x00, 0x18, 0x0D, 0x06, 0x03,
0x13, 0x04, 0x3C, 0x01, 0x7F, 0x18, 0x0D, 0x06, 0x13, 0x13, 0x02, 0x00,
0x05, 0x06, 0x2E, 0x01, 0x03, 0x2D, 0x04, 0x03, 0x01, 0x7F, 0x23, 0x01,
0x00, 0x00, 0x04, 0x23, 0x01, 0x01, 0x18, 0x0D, 0x06, 0x09, 0x13, 0x01,
0x00, 0x23, 0x01, 0x00, 0x00, 0x04, 0x14, 0x01, 0x02, 0x18, 0x0D, 0x06,
0x06, 0x13, 0x01, 0x7F, 0x00, 0x04, 0x08, 0x13, 0x01, 0x03, 0x2D, 0x01,
0x00, 0x00, 0x13, 0x01, 0x00, 0x03, 0x00, 0x04, 0xFF, 0x33, 0x01, 0x2C,
0x14, 0x01, 0x2D, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x7F, 0x00, 0x14, 0x31,
0x06, 0x02, 0x13, 0x29, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x04, 0x13, 0x01,
0x02, 0x00, 0x25, 0x14, 0x1C, 0x06, 0x05, 0x13, 0x2E, 0x01, 0x03, 0x00,
0x02, 0x00, 0x16, 0x14, 0x1D, 0x06, 0x05, 0x13, 0x2E, 0x01, 0x03, 0x00,
0x03, 0x00, 0x29, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x03,
0x00, 0x25, 0x14, 0x1C, 0x06, 0x05, 0x13, 0x2E, 0x01, 0x03, 0x00, 0x02,
0x00, 0x16, 0x14, 0x1D, 0x06, 0x05, 0x13, 0x2E, 0x01, 0x03, 0x00, 0x02,
0x00, 0x01, 0x06, 0x0A, 0x07, 0x03, 0x00, 0x29, 0x14, 0x01, 0x0A, 0x0D,
0x06, 0x04, 0x13, 0x01, 0x03, 0x00, 0x14, 0x01, 0x3D, 0x0D, 0x06, 0x2E,
0x13, 0x29, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x03, 0x00,
0x2F, 0x05, 0x04, 0x13, 0x01, 0x03, 0x00, 0x01, 0x3D, 0x0C, 0x06, 0x03,
0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x0F, 0x10, 0x06, 0x03, 0x01, 0x03,
0x00, 0x02, 0x00, 0x01, 0x04, 0x0F, 0x1B, 0x01, 0x01, 0x00, 0x25, 0x14,
0x1C, 0x06, 0x05, 0x13, 0x2E, 0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x06,
0x00, 0x02, 0x00, 0x01, 0x04, 0x0F, 0x1C, 0x01, 0x01, 0x00, 0x16, 0x14,
0x1D, 0x06, 0x05, 0x13, 0x2E, 0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x06,
0x0A, 0x07, 0x03, 0x00, 0x29, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x04, 0x13,
0x01, 0x03, 0x00, 0x14, 0x01, 0x3D, 0x0D, 0x06, 0x20, 0x13, 0x2F, 0x05,
0x03, 0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x03, 0x10, 0x06, 0x03, 0x01,
0x03, 0x00, 0x02, 0x00, 0x01, 0x0A, 0x0F, 0x1B, 0x02, 0x00, 0x01, 0x02,
0x0F, 0x1B, 0x01, 0x01, 0x00, 0x25, 0x14, 0x1C, 0x06, 0x05, 0x13, 0x2E,
0x03, 0x00, 0x02, 0x00, 0x01, 0x0A, 0x0F, 0x1C, 0x02, 0x00, 0x01, 0x02,
0x0F, 0x1C, 0x01, 0x01, 0x00, 0x16, 0x14, 0x1D, 0x06, 0x05, 0x13, 0x2E,
0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x06, 0x0A, 0x07, 0x03, 0x00, 0x02,
0x00, 0x01, 0x10, 0x0F, 0x1B, 0x02, 0x00, 0x01, 0x08, 0x0F, 0x1B, 0x02,
0x00, 0x1B, 0x01, 0x00, 0x00, 0x00, 0x14, 0x14, 0x01, 0x80, 0x41, 0x0E,
0x1A, 0x01, 0x80, 0x5A, 0x0B, 0x10, 0x06, 0x05, 0x01, 0x80, 0x41, 0x08,
0x00, 0x14, 0x14, 0x01, 0x80, 0x61, 0x0E, 0x1A, 0x01, 0x80, 0x7A, 0x0B,
0x10, 0x06, 0x05, 0x01, 0x80, 0x47, 0x08, 0x00, 0x14, 0x14, 0x01, 0x30,
0x0E, 0x1A, 0x01, 0x39, 0x0B, 0x10, 0x06, 0x04, 0x01, 0x04, 0x07, 0x00,
0x14, 0x01, 0x2B, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x3E, 0x00, 0x14, 0x01,
0x2F, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x3F, 0x00, 0x01, 0x3D, 0x0C, 0x1E,
0x00, 0x00, 0x28, 0x01, 0x01, 0x2D, 0x23, 0x06, 0x02, 0x04, 0x7B, 0x04,
0x75, 0x00, 0x14, 0x12, 0x2A, 0x14, 0x05, 0x04, 0x1F, 0x01, 0x7F, 0x00,
0x2C, 0x2A, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x05, 0x13, 0x1F, 0x01, 0x00,
0x00, 0x0D, 0x05, 0x05, 0x13, 0x2E, 0x01, 0x00, 0x00, 0x1D, 0x04, 0x5E,
0x00, 0x01, 0x01, 0x27, 0x06, 0x0B, 0x21, 0x01, 0x80, 0x7F, 0x2B, 0x14,
0x06, 0x02, 0x30, 0x00, 0x13, 0x04, 0x6E, 0x00, 0x2C, 0x14, 0x31, 0x05,
0x01, 0x00, 0x13, 0x04, 0x77, 0x00, 0x14, 0x14, 0x01, 0x80, 0x61, 0x0E,
0x1A, 0x01, 0x80, 0x7A, 0x0B, 0x10, 0x06, 0x03, 0x01, 0x20, 0x08, 0x00,
0x01, 0x14, 0x03, 0x00, 0x1A, 0x17, 0x05, 0x05, 0x1F, 0x2E, 0x01, 0x00,
0x00, 0x2C, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x06, 0x1F, 0x02, 0x00, 0x1A,
0x08, 0x00, 0x14, 0x01, 0x0D, 0x0D, 0x06, 0x03, 0x13, 0x04, 0x03, 0x2A,
0x17, 0x19, 0x1D, 0x1A, 0x1E, 0x1A, 0x04, 0x59, 0x00, 0x18, 0x14, 0x1C,
0x05, 0x01, 0x00, 0x13, 0x11, 0x04, 0x76, 0x00, 0x20, 0x19, 0x11, 0x00,
0x00, 0x2C, 0x01, 0x0A, 0x0C, 0x06, 0x02, 0x04, 0x78, 0x00, 0x01, 0x01,
0x7F, 0x03, 0x00, 0x2C, 0x14, 0x01, 0x0A, 0x0C, 0x06, 0x09, 0x31, 0x05,
0x04, 0x01, 0x00, 0x03, 0x00, 0x04, 0x70, 0x13, 0x02, 0x00, 0x00, 0x00,
0x14, 0x06, 0x14, 0x1E, 0x14, 0x21, 0x07, 0x16, 0x01, 0x2D, 0x0C, 0x06,
0x08, 0x21, 0x07, 0x1D, 0x01, 0x00, 0x1A, 0x19, 0x00, 0x04, 0x69, 0x21,
0x19, 0x00, 0x00, 0x14, 0x01, 0x0A, 0x0C, 0x1A, 0x01, 0x20, 0x0B, 0x10,
0x00
0x00, 0x01, 0x10, 0x0F, 0x1C, 0x02, 0x00, 0x01, 0x08, 0x0F, 0x1C, 0x02,
0x00, 0x1C, 0x01, 0x00, 0x00, 0x00, 0x28, 0x01, 0x01, 0x2D, 0x24, 0x06,
0x02, 0x04, 0x7B, 0x04, 0x75, 0x00, 0x14, 0x12, 0x2A, 0x14, 0x05, 0x04,
0x20, 0x01, 0x7F, 0x00, 0x2C, 0x2A, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x05,
0x13, 0x20, 0x01, 0x00, 0x00, 0x0D, 0x05, 0x05, 0x13, 0x2E, 0x01, 0x00,
0x00, 0x1E, 0x04, 0x5E, 0x00, 0x01, 0x01, 0x27, 0x06, 0x0B, 0x22, 0x01,
0x80, 0x7F, 0x2B, 0x14, 0x06, 0x02, 0x30, 0x00, 0x13, 0x04, 0x6E, 0x00,
0x2C, 0x14, 0x31, 0x05, 0x01, 0x00, 0x13, 0x04, 0x77, 0x00, 0x14, 0x14,
0x01, 0x80, 0x61, 0x0E, 0x1B, 0x01, 0x80, 0x7A, 0x0B, 0x10, 0x06, 0x03,
0x01, 0x20, 0x08, 0x00, 0x01, 0x14, 0x03, 0x00, 0x1B, 0x18, 0x05, 0x05,
0x20, 0x2E, 0x01, 0x00, 0x00, 0x2C, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x06,
0x20, 0x02, 0x00, 0x1B, 0x08, 0x00, 0x14, 0x01, 0x0D, 0x0D, 0x06, 0x03,
0x13, 0x04, 0x03, 0x2A, 0x18, 0x1A, 0x1E, 0x1B, 0x1F, 0x1B, 0x04, 0x59,
0x00, 0x19, 0x14, 0x1D, 0x05, 0x01, 0x00, 0x13, 0x11, 0x04, 0x76, 0x00,
0x21, 0x1A, 0x11, 0x00, 0x00, 0x2C, 0x01, 0x0A, 0x0C, 0x06, 0x02, 0x04,
0x78, 0x00, 0x01, 0x01, 0x7F, 0x03, 0x00, 0x2C, 0x14, 0x01, 0x0A, 0x0C,
0x06, 0x09, 0x31, 0x05, 0x04, 0x01, 0x00, 0x03, 0x00, 0x04, 0x70, 0x13,
0x02, 0x00, 0x00, 0x00, 0x14, 0x06, 0x14, 0x1F, 0x14, 0x22, 0x07, 0x17,
0x01, 0x2D, 0x0C, 0x06, 0x08, 0x22, 0x07, 0x1E, 0x01, 0x00, 0x1B, 0x1A,
0x00, 0x04, 0x69, 0x22, 0x1A, 0x00, 0x00, 0x14, 0x01, 0x0A, 0x0C, 0x1B,
0x01, 0x20, 0x0B, 0x10, 0x00
};
static const uint16_t t0_caddr[] = {
@ -188,21 +181,20 @@ static const uint16_t t0_caddr[] = {
67,
149,
384,
464,
476,
511,
530,
540,
559,
603,
614,
619,
629,
654,
681
396,
431,
450,
460,
479,
523,
534,
539,
549,
574,
601
};
#define T0_INTERPRETED 28
#define T0_INTERPRETED 29
#define T0_ENTER(ip, rp, slot) do { \
const unsigned char *t0_newip; \
@ -450,6 +442,25 @@ br_pem_decoder_run(void *t0ctx)
}
break;
case 22: {
/* from-base64 */
uint32_t c = T0_POP();
uint32_t p, q, r, z;
p = c - 0x41;
q = c - 0x61;
r = c - 0x30;
z = ((p + 2) & -LT(p, 26))
| ((q + 28) & -LT(q, 26))
| ((r + 54) & -LT(r, 10))
| (64 & -EQ(c, 0x2B))
| (65 & -EQ(c, 0x2F))
| EQ(c, 0x3D);
T0_PUSHi((int32_t)z - 2);
}
break;
case 23: {
/* get8 */
size_t addr = T0_POP();
@ -457,12 +468,12 @@ br_pem_decoder_run(void *t0ctx)
}
break;
case 23: {
case 24: {
/* over */
T0_PUSH(T0_PEEK(1));
}
break;
case 24: {
case 25: {
/* read8-native */
if (CTX->hlen > 0) {
@ -474,7 +485,7 @@ br_pem_decoder_run(void *t0ctx)
}
break;
case 25: {
case 26: {
/* set8 */
size_t addr = T0_POP();
@ -483,12 +494,12 @@ br_pem_decoder_run(void *t0ctx)
}
break;
case 26: {
case 27: {
/* swap */
T0_SWAP();
}
break;
case 27: {
case 28: {
/* write8 */
unsigned char x = (unsigned char)T0_POP();

View file

@ -170,13 +170,21 @@ cc: read8-native ( -- x ) {
\ Convert a Base64 character to its numerical value. Returned value is
\ 0 to 63 for Base64 characters, -1 for '=', and -2 for all other characters.
: from-base64 ( char -- x )
dup dup `A >= swap `Z <= and if 65 - ret then
dup dup `a >= swap `z <= and if 71 - ret then
dup dup `0 >= swap `9 <= and if 4 + ret then
dup `+ = if drop 62 ret then
dup `/ = if drop 63 ret then
`= <> 1- ;
cc: from-base64 ( char -- x ) {
uint32_t c = T0_POP();
uint32_t p, q, r, z;
p = c - 0x41;
q = c - 0x61;
r = c - 0x30;
z = ((p + 2) & -LT(p, 26))
| ((q + 28) & -LT(q, 26))
| ((r + 54) & -LT(r, 10))
| (64 & -EQ(c, 0x2B))
| (65 & -EQ(c, 0x2F))
| EQ(c, 0x3D);
T0_PUSHi((int32_t)z - 2);
}
\ Test whether a character is whitespace (but not a newline).
: ws? ( x -- bool )