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, 0x14, 0x2C, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x03, 0x13, 0x04, 0x76, 0x01,
0x2D, 0x0C, 0x06, 0x05, 0x2E, 0x01, 0x03, 0x2D, 0x00, 0x01, 0x0D, 0x27, 0x2D, 0x0C, 0x06, 0x05, 0x2E, 0x01, 0x03, 0x2D, 0x00, 0x01, 0x0D, 0x27,
0x05, 0x04, 0x01, 0x03, 0x2D, 0x00, 0x15, 0x2E, 0x01, 0x02, 0x2D, 0x00, 0x05, 0x04, 0x01, 0x03, 0x2D, 0x00, 0x15, 0x2E, 0x01, 0x02, 0x2D, 0x00,
0x01, 0x01, 0x7F, 0x03, 0x00, 0x24, 0x01, 0x00, 0x17, 0x0D, 0x06, 0x03, 0x01, 0x01, 0x7F, 0x03, 0x00, 0x25, 0x01, 0x00, 0x18, 0x0D, 0x06, 0x03,
0x13, 0x04, 0x3C, 0x01, 0x7F, 0x17, 0x0D, 0x06, 0x13, 0x13, 0x02, 0x00, 0x13, 0x04, 0x3C, 0x01, 0x7F, 0x18, 0x0D, 0x06, 0x13, 0x13, 0x02, 0x00,
0x05, 0x06, 0x2E, 0x01, 0x03, 0x2D, 0x04, 0x03, 0x01, 0x7F, 0x22, 0x01, 0x05, 0x06, 0x2E, 0x01, 0x03, 0x2D, 0x04, 0x03, 0x01, 0x7F, 0x23, 0x01,
0x00, 0x00, 0x04, 0x23, 0x01, 0x01, 0x17, 0x0D, 0x06, 0x09, 0x13, 0x01, 0x00, 0x00, 0x04, 0x23, 0x01, 0x01, 0x18, 0x0D, 0x06, 0x09, 0x13, 0x01,
0x00, 0x22, 0x01, 0x00, 0x00, 0x04, 0x14, 0x01, 0x02, 0x17, 0x0D, 0x06, 0x00, 0x23, 0x01, 0x00, 0x00, 0x04, 0x14, 0x01, 0x02, 0x18, 0x0D, 0x06,
0x06, 0x13, 0x01, 0x7F, 0x00, 0x04, 0x08, 0x13, 0x01, 0x03, 0x2D, 0x01, 0x06, 0x13, 0x01, 0x7F, 0x00, 0x04, 0x08, 0x13, 0x01, 0x03, 0x2D, 0x01,
0x00, 0x00, 0x13, 0x01, 0x00, 0x03, 0x00, 0x04, 0xFF, 0x33, 0x01, 0x2C, 0x00, 0x00, 0x13, 0x01, 0x00, 0x03, 0x00, 0x04, 0xFF, 0x33, 0x01, 0x2C,
0x14, 0x01, 0x2D, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x7F, 0x00, 0x14, 0x31, 0x14, 0x01, 0x2D, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x7F, 0x00, 0x14, 0x31,
0x06, 0x02, 0x13, 0x29, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x04, 0x13, 0x01, 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, 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, 0x00, 0x01, 0x06, 0x0A, 0x07, 0x03, 0x00, 0x29, 0x14, 0x01, 0x0A, 0x0D,
0x06, 0x04, 0x13, 0x01, 0x03, 0x00, 0x14, 0x01, 0x3D, 0x0D, 0x06, 0x2E, 0x06, 0x04, 0x13, 0x01, 0x03, 0x00, 0x14, 0x01, 0x3D, 0x0D, 0x06, 0x2E,
0x13, 0x29, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x03, 0x00, 0x13, 0x29, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x03, 0x00,
0x2F, 0x05, 0x04, 0x13, 0x01, 0x03, 0x00, 0x01, 0x3D, 0x0C, 0x06, 0x03, 0x2F, 0x05, 0x04, 0x13, 0x01, 0x03, 0x00, 0x01, 0x3D, 0x0C, 0x06, 0x03,
0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x0F, 0x10, 0x06, 0x03, 0x01, 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, 0x00, 0x02, 0x00, 0x01, 0x04, 0x0F, 0x1C, 0x01, 0x01, 0x00, 0x16, 0x14,
0x1C, 0x06, 0x05, 0x13, 0x2E, 0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x06, 0x1D, 0x06, 0x05, 0x13, 0x2E, 0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x06,
0x0A, 0x07, 0x03, 0x00, 0x29, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x04, 0x13, 0x0A, 0x07, 0x03, 0x00, 0x29, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x04, 0x13,
0x01, 0x03, 0x00, 0x14, 0x01, 0x3D, 0x0D, 0x06, 0x20, 0x13, 0x2F, 0x05, 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, 0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x03, 0x10, 0x06, 0x03, 0x01,
0x03, 0x00, 0x02, 0x00, 0x01, 0x0A, 0x0F, 0x1B, 0x02, 0x00, 0x01, 0x02, 0x03, 0x00, 0x02, 0x00, 0x01, 0x0A, 0x0F, 0x1C, 0x02, 0x00, 0x01, 0x02,
0x0F, 0x1B, 0x01, 0x01, 0x00, 0x25, 0x14, 0x1C, 0x06, 0x05, 0x13, 0x2E, 0x0F, 0x1C, 0x01, 0x01, 0x00, 0x16, 0x14, 0x1D, 0x06, 0x05, 0x13, 0x2E,
0x01, 0x03, 0x00, 0x02, 0x00, 0x01, 0x06, 0x0A, 0x07, 0x03, 0x00, 0x02, 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, 0x01, 0x10, 0x0F, 0x1C, 0x02, 0x00, 0x01, 0x08, 0x0F, 0x1C, 0x02,
0x00, 0x1B, 0x01, 0x00, 0x00, 0x00, 0x14, 0x14, 0x01, 0x80, 0x41, 0x0E, 0x00, 0x1C, 0x01, 0x00, 0x00, 0x00, 0x28, 0x01, 0x01, 0x2D, 0x24, 0x06,
0x1A, 0x01, 0x80, 0x5A, 0x0B, 0x10, 0x06, 0x05, 0x01, 0x80, 0x41, 0x08, 0x02, 0x04, 0x7B, 0x04, 0x75, 0x00, 0x14, 0x12, 0x2A, 0x14, 0x05, 0x04,
0x00, 0x14, 0x14, 0x01, 0x80, 0x61, 0x0E, 0x1A, 0x01, 0x80, 0x7A, 0x0B, 0x20, 0x01, 0x7F, 0x00, 0x2C, 0x2A, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x05,
0x10, 0x06, 0x05, 0x01, 0x80, 0x47, 0x08, 0x00, 0x14, 0x14, 0x01, 0x30, 0x13, 0x20, 0x01, 0x00, 0x00, 0x0D, 0x05, 0x05, 0x13, 0x2E, 0x01, 0x00,
0x0E, 0x1A, 0x01, 0x39, 0x0B, 0x10, 0x06, 0x04, 0x01, 0x04, 0x07, 0x00, 0x00, 0x1E, 0x04, 0x5E, 0x00, 0x01, 0x01, 0x27, 0x06, 0x0B, 0x22, 0x01,
0x14, 0x01, 0x2B, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x3E, 0x00, 0x14, 0x01, 0x80, 0x7F, 0x2B, 0x14, 0x06, 0x02, 0x30, 0x00, 0x13, 0x04, 0x6E, 0x00,
0x2F, 0x0D, 0x06, 0x04, 0x13, 0x01, 0x3F, 0x00, 0x01, 0x3D, 0x0C, 0x1E, 0x2C, 0x14, 0x31, 0x05, 0x01, 0x00, 0x13, 0x04, 0x77, 0x00, 0x14, 0x14,
0x00, 0x00, 0x28, 0x01, 0x01, 0x2D, 0x23, 0x06, 0x02, 0x04, 0x7B, 0x04, 0x01, 0x80, 0x61, 0x0E, 0x1B, 0x01, 0x80, 0x7A, 0x0B, 0x10, 0x06, 0x03,
0x75, 0x00, 0x14, 0x12, 0x2A, 0x14, 0x05, 0x04, 0x1F, 0x01, 0x7F, 0x00, 0x01, 0x20, 0x08, 0x00, 0x01, 0x14, 0x03, 0x00, 0x1B, 0x18, 0x05, 0x05,
0x2C, 0x2A, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x05, 0x13, 0x1F, 0x01, 0x00, 0x20, 0x2E, 0x01, 0x00, 0x00, 0x2C, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x06,
0x00, 0x0D, 0x05, 0x05, 0x13, 0x2E, 0x01, 0x00, 0x00, 0x1D, 0x04, 0x5E, 0x20, 0x02, 0x00, 0x1B, 0x08, 0x00, 0x14, 0x01, 0x0D, 0x0D, 0x06, 0x03,
0x00, 0x01, 0x01, 0x27, 0x06, 0x0B, 0x21, 0x01, 0x80, 0x7F, 0x2B, 0x14, 0x13, 0x04, 0x03, 0x2A, 0x18, 0x1A, 0x1E, 0x1B, 0x1F, 0x1B, 0x04, 0x59,
0x06, 0x02, 0x30, 0x00, 0x13, 0x04, 0x6E, 0x00, 0x2C, 0x14, 0x31, 0x05, 0x00, 0x19, 0x14, 0x1D, 0x05, 0x01, 0x00, 0x13, 0x11, 0x04, 0x76, 0x00,
0x01, 0x00, 0x13, 0x04, 0x77, 0x00, 0x14, 0x14, 0x01, 0x80, 0x61, 0x0E, 0x21, 0x1A, 0x11, 0x00, 0x00, 0x2C, 0x01, 0x0A, 0x0C, 0x06, 0x02, 0x04,
0x1A, 0x01, 0x80, 0x7A, 0x0B, 0x10, 0x06, 0x03, 0x01, 0x20, 0x08, 0x00, 0x78, 0x00, 0x01, 0x01, 0x7F, 0x03, 0x00, 0x2C, 0x14, 0x01, 0x0A, 0x0C,
0x01, 0x14, 0x03, 0x00, 0x1A, 0x17, 0x05, 0x05, 0x1F, 0x2E, 0x01, 0x00, 0x06, 0x09, 0x31, 0x05, 0x04, 0x01, 0x00, 0x03, 0x00, 0x04, 0x70, 0x13,
0x00, 0x2C, 0x14, 0x01, 0x0A, 0x0D, 0x06, 0x06, 0x1F, 0x02, 0x00, 0x1A, 0x02, 0x00, 0x00, 0x00, 0x14, 0x06, 0x14, 0x1F, 0x14, 0x22, 0x07, 0x17,
0x08, 0x00, 0x14, 0x01, 0x0D, 0x0D, 0x06, 0x03, 0x13, 0x04, 0x03, 0x2A, 0x01, 0x2D, 0x0C, 0x06, 0x08, 0x22, 0x07, 0x1E, 0x01, 0x00, 0x1B, 0x1A,
0x17, 0x19, 0x1D, 0x1A, 0x1E, 0x1A, 0x04, 0x59, 0x00, 0x18, 0x14, 0x1C, 0x00, 0x04, 0x69, 0x22, 0x1A, 0x00, 0x00, 0x14, 0x01, 0x0A, 0x0C, 0x1B,
0x05, 0x01, 0x00, 0x13, 0x11, 0x04, 0x76, 0x00, 0x20, 0x19, 0x11, 0x00, 0x01, 0x20, 0x0B, 0x10, 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
}; };
static const uint16_t t0_caddr[] = { static const uint16_t t0_caddr[] = {
@ -188,21 +181,20 @@ static const uint16_t t0_caddr[] = {
67, 67,
149, 149,
384, 384,
464, 396,
476, 431,
511, 450,
530, 460,
540, 479,
559, 523,
603, 534,
614, 539,
619, 549,
629, 574,
654, 601
681
}; };
#define T0_INTERPRETED 28 #define T0_INTERPRETED 29
#define T0_ENTER(ip, rp, slot) do { \ #define T0_ENTER(ip, rp, slot) do { \
const unsigned char *t0_newip; \ const unsigned char *t0_newip; \
@ -450,6 +442,25 @@ br_pem_decoder_run(void *t0ctx)
} }
break; break;
case 22: { 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 */ /* get8 */
size_t addr = T0_POP(); size_t addr = T0_POP();
@ -457,12 +468,12 @@ br_pem_decoder_run(void *t0ctx)
} }
break; break;
case 23: { case 24: {
/* over */ /* over */
T0_PUSH(T0_PEEK(1)); T0_PUSH(T0_PEEK(1));
} }
break; break;
case 24: { case 25: {
/* read8-native */ /* read8-native */
if (CTX->hlen > 0) { if (CTX->hlen > 0) {
@ -474,7 +485,7 @@ br_pem_decoder_run(void *t0ctx)
} }
break; break;
case 25: { case 26: {
/* set8 */ /* set8 */
size_t addr = T0_POP(); size_t addr = T0_POP();
@ -483,12 +494,12 @@ br_pem_decoder_run(void *t0ctx)
} }
break; break;
case 26: { case 27: {
/* swap */ /* swap */
T0_SWAP(); T0_SWAP();
} }
break; break;
case 27: { case 28: {
/* write8 */ /* write8 */
unsigned char x = (unsigned char)T0_POP(); 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 \ 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. \ 0 to 63 for Base64 characters, -1 for '=', and -2 for all other characters.
: from-base64 ( char -- x ) cc: from-base64 ( char -- x ) {
dup dup `A >= swap `Z <= and if 65 - ret then uint32_t c = T0_POP();
dup dup `a >= swap `z <= and if 71 - ret then uint32_t p, q, r, z;
dup dup `0 >= swap `9 <= and if 4 + ret then p = c - 0x41;
dup `+ = if drop 62 ret then q = c - 0x61;
dup `/ = if drop 63 ret then r = c - 0x30;
`= <> 1- ;
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). \ Test whether a character is whitespace (but not a newline).
: ws? ( x -- bool ) : ws? ( x -- bool )