From ffe3c9166b35cdb220cc0ecc1614afb8451ae420 Mon Sep 17 00:00:00 2001 From: Thomas Pornin Date: Mon, 6 Aug 2018 00:16:09 +0200 Subject: [PATCH] Made Base64 decoding constant-time (with regards to actual data byte contents). --- src/codec/pemdec.c | 125 ++++++++++++++++++++++++-------------------- src/codec/pemdec.t0 | 22 +++++--- 2 files changed, 83 insertions(+), 64 deletions(-) diff --git a/src/codec/pemdec.c b/src/codec/pemdec.c index b599f84..8e54e6d 100644 --- a/src/codec/pemdec.c +++ b/src/codec/pemdec.c @@ -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(); diff --git a/src/codec/pemdec.t0 b/src/codec/pemdec.t0 index 4ebf0dd..2237abb 100644 --- a/src/codec/pemdec.t0 +++ b/src/codec/pemdec.t0 @@ -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 ) -- 2.17.1