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app-ethereum/src_common/uint256.c
BTChip 3e3b9dcc6a Initial import
2016-06-01 21:41:29 +02:00

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/*******************************************************************************
* Ledger Blue
* (c) 2016 Ledger
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
********************************************************************************/
// Adapted from https://github.com/calccrypto/uint256_t
#include <stdio.h>
#include <stdlib.h>
#include "uint256.h"
static const char HEXDIGITS[] = "0123456789abcdef";
static uint64_t readUint64BE(uint8_t *buffer) {
return (((uint64_t)buffer[0]) << 56) | (((uint64_t)buffer[1]) << 48) |
(((uint64_t)buffer[2]) << 40) | (((uint64_t)buffer[3]) << 32) |
(((uint64_t)buffer[4]) << 24) | (((uint64_t)buffer[5]) << 16) |
(((uint64_t)buffer[6]) << 8) | (((uint64_t)buffer[7]));
}
void readu128BE(uint8_t *buffer, uint128_t *target) {
UPPER_P(target) = readUint64BE(buffer);
LOWER_P(target) = readUint64BE(buffer + 8);
}
void readu256BE(uint8_t *buffer, uint256_t *target) {
readu128BE(buffer, &UPPER_P(target));
readu128BE(buffer + 16, &LOWER_P(target));
}
bool zero128(uint128_t *number) {
return ((LOWER_P(number) == 0) && (UPPER_P(number) == 0));
}
bool zero256(uint256_t *number) {
return (zero128(&LOWER_P(number)) && zero128(&UPPER_P(number)));
}
void copy128(uint128_t *target, uint128_t *number) {
UPPER_P(target) = UPPER_P(number);
LOWER_P(target) = LOWER_P(number);
}
void copy256(uint256_t *target, uint256_t *number) {
copy128(&UPPER_P(target), &UPPER_P(number));
copy128(&LOWER_P(target), &LOWER_P(number));
}
void clear128(uint128_t *target) {
UPPER_P(target) = 0;
LOWER_P(target) = 0;
}
void clear256(uint256_t *target) {
clear128(&UPPER_P(target));
clear128(&LOWER_P(target));
}
void shiftl128(uint128_t *number, uint32_t value, uint128_t *target) {
if (value >= 128) {
clear128(target);
} else if (value == 64) {
UPPER_P(target) = LOWER_P(number);
LOWER_P(target) = 0;
} else if (value == 0) {
copy128(target, number);
} else if (value < 64) {
UPPER_P(target) =
(UPPER_P(number) << value) + (LOWER_P(number) >> (64 - value));
LOWER_P(target) = (LOWER_P(number) << value);
} else if ((128 > value) && (value > 64)) {
UPPER_P(target) = LOWER_P(number) << (value - 64);
LOWER_P(target) = 0;
} else {
clear128(target);
}
}
void shiftl256(uint256_t *number, uint32_t value, uint256_t *target) {
if (value >= 256) {
clear256(target);
} else if (value == 128) {
copy128(&UPPER_P(target), &LOWER_P(number));
clear128(&LOWER_P(target));
} else if (value == 0) {
copy256(target, number);
} else if (value < 128) {
uint128_t tmp1;
uint128_t tmp2;
uint256_t result;
shiftl128(&UPPER_P(number), value, &tmp1);
shiftr128(&LOWER_P(number), (128 - value), &tmp2);
add128(&tmp1, &tmp2, &UPPER(result));
shiftl128(&LOWER_P(number), value, &LOWER(result));
copy256(target, &result);
} else if ((256 > value) && (value > 128)) {
shiftl128(&LOWER_P(number), (value - 128), &UPPER_P(target));
clear128(&LOWER_P(target));
} else {
clear256(target);
}
}
void shiftr128(uint128_t *number, uint32_t value, uint128_t *target) {
if (value >= 128) {
clear128(target);
} else if (value == 64) {
UPPER_P(target) = 0;
LOWER_P(target) = UPPER_P(number);
} else if (value == 0) {
copy128(target, number);
} else if (value < 64) {
uint128_t result;
UPPER(result) = UPPER_P(number) >> value;
LOWER(result) =
(UPPER_P(number) << (64 - value)) + (LOWER_P(number) >> value);
copy128(target, &result);
} else if ((128 > value) && (value > 64)) {
LOWER_P(target) = UPPER_P(number) >> (value - 64);
UPPER_P(target) = 0;
} else {
clear128(target);
}
}
void shiftr256(uint256_t *number, uint32_t value, uint256_t *target) {
if (value >= 256) {
clear256(target);
} else if (value == 128) {
copy128(&LOWER_P(target), &UPPER_P(number));
clear128(&UPPER_P(target));
} else if (value == 0) {
copy256(target, number);
} else if (value < 128) {
uint128_t tmp1;
uint128_t tmp2;
uint256_t result;
shiftr128(&UPPER_P(number), value, &UPPER(result));
shiftr128(&LOWER_P(number), value, &tmp1);
shiftl128(&UPPER_P(number), (128 - value), &tmp2);
add128(&tmp1, &tmp2, &LOWER(result));
copy256(target, &result);
} else if ((256 > value) && (value > 128)) {
shiftr128(&UPPER_P(number), (value - 128), &LOWER_P(target));
clear128(&UPPER_P(target));
} else {
clear256(target);
}
}
uint32_t bits128(uint128_t *number) {
uint32_t result = 0;
if (UPPER_P(number)) {
result = 64;
uint64_t up = UPPER_P(number);
while (up) {
up >>= 1;
result++;
}
} else {
uint64_t low = LOWER_P(number);
while (low) {
low >>= 1;
result++;
}
}
return result;
}
uint32_t bits256(uint256_t *number) {
uint32_t result = 0;
if (!zero128(&UPPER_P(number))) {
result = 128;
uint128_t up;
copy128(&up, &UPPER_P(number));
while (!zero128(&up)) {
shiftr128(&up, 1, &up);
result++;
}
} else {
uint128_t low;
copy128(&low, &LOWER_P(number));
while (!zero128(&low)) {
shiftr128(&low, 1, &low);
result++;
}
}
return result;
}
bool equal128(uint128_t *number1, uint128_t *number2) {
return (UPPER_P(number1) == UPPER_P(number2)) &&
(LOWER_P(number1) == LOWER_P(number2));
}
bool equal256(uint256_t *number1, uint256_t *number2) {
return (equal128(&UPPER_P(number1), &UPPER_P(number2)) &&
equal128(&LOWER_P(number1), &LOWER_P(number2)));
}
bool gt128(uint128_t *number1, uint128_t *number2) {
if (UPPER_P(number1) == UPPER_P(number2)) {
return (LOWER_P(number1) > LOWER_P(number2));
}
return (UPPER_P(number1) > UPPER_P(number2));
}
bool gt256(uint256_t *number1, uint256_t *number2) {
if (equal128(&UPPER_P(number1), &UPPER_P(number2))) {
return gt128(&LOWER_P(number1), &LOWER_P(number2));
}
return gt128(&UPPER_P(number1), &UPPER_P(number2));
}
bool gte128(uint128_t *number1, uint128_t *number2) {
return gt128(number1, number2) || equal128(number1, number2);
}
bool gte256(uint256_t *number1, uint256_t *number2) {
return gt256(number1, number2) || equal256(number1, number2);
}
void add128(uint128_t *number1, uint128_t *number2, uint128_t *target) {
UPPER_P(target) =
UPPER_P(number1) + UPPER_P(number2) +
((LOWER_P(number1) + LOWER_P(number2)) < LOWER_P(number1));
LOWER_P(target) = LOWER_P(number1) + LOWER_P(number2);
}
void add256(uint256_t *number1, uint256_t *number2, uint256_t *target) {
uint128_t tmp;
add128(&UPPER_P(number1), &UPPER_P(number2), &UPPER_P(target));
add128(&LOWER_P(number1), &LOWER_P(number2), &tmp);
if (gt128(&LOWER_P(number1), &tmp)) {
uint128_t one;
UPPER(one) = 0;
LOWER(one) = 1;
add128(&UPPER_P(target), &one, &UPPER_P(target));
}
add128(&LOWER_P(number1), &LOWER_P(number2), &LOWER_P(target));
}
void minus128(uint128_t *number1, uint128_t *number2, uint128_t *target) {
UPPER_P(target) =
UPPER_P(number1) - UPPER_P(number2) -
((LOWER_P(number1) - LOWER_P(number2)) > LOWER_P(number1));
LOWER_P(target) = LOWER_P(number1) - LOWER_P(number2);
}
void minus256(uint256_t *number1, uint256_t *number2, uint256_t *target) {
uint128_t tmp;
minus128(&UPPER_P(number1), &UPPER_P(number2), &UPPER_P(target));
minus128(&LOWER_P(number1), &LOWER_P(number2), &tmp);
if (gt128(&tmp, &LOWER_P(number1))) {
uint128_t one;
UPPER(one) = 0;
LOWER(one) = 1;
minus128(&UPPER_P(target), &one, &UPPER_P(target));
}
minus128(&LOWER_P(number1), &LOWER_P(number2), &LOWER_P(target));
}
void or128(uint128_t *number1, uint128_t *number2, uint128_t *target) {
UPPER_P(target) = UPPER_P(number1) | UPPER_P(number2);
LOWER_P(target) = LOWER_P(number1) | LOWER_P(number2);
}
void or256(uint256_t *number1, uint256_t *number2, uint256_t *target) {
or128(&UPPER_P(number1), &UPPER_P(number2), &UPPER_P(target));
or128(&LOWER_P(number1), &LOWER_P(number2), &LOWER_P(target));
}
void divmod128(uint128_t *l, uint128_t *r, uint128_t *retDiv,
uint128_t *retMod) {
uint128_t copyd, adder, resDiv, resMod;
uint128_t one;
UPPER(one) = 0;
LOWER(one) = 1;
uint32_t diffBits = bits128(l) - bits128(r);
clear128(&resDiv);
copy128(&resMod, l);
if (gt128(r, l)) {
copy128(retMod, l);
clear128(retDiv);
} else {
shiftl128(r, diffBits, &copyd);
shiftl128(&one, diffBits, &adder);
if (gt128(&copyd, &resMod)) {
shiftr128(&copyd, 1, &copyd);
shiftr128(&adder, 1, &adder);
}
while (gte128(&resMod, r)) {
if (gte128(&resMod, &copyd)) {
minus128(&resMod, &copyd, &resMod);
or128(&resDiv, &adder, &resDiv);
}
shiftr128(&copyd, 1, &copyd);
shiftr128(&adder, 1, &adder);
}
copy128(retDiv, &resDiv);
copy128(retMod, &resMod);
}
}
void divmod256(uint256_t *l, uint256_t *r, uint256_t *retDiv,
uint256_t *retMod) {
uint256_t copyd, adder, resDiv, resMod;
uint256_t one;
clear256(&one);
UPPER(LOWER(one)) = 0;
LOWER(LOWER(one)) = 1;
uint32_t diffBits = bits256(l) - bits256(r);
clear256(&resDiv);
copy256(&resMod, l);
if (gt256(r, l)) {
copy256(retMod, l);
clear256(retDiv);
} else {
shiftl256(r, diffBits, &copyd);
shiftl256(&one, diffBits, &adder);
if (gt256(&copyd, &resMod)) {
shiftr256(&copyd, 1, &copyd);
shiftr256(&adder, 1, &adder);
}
while (gte256(&resMod, r)) {
if (gte256(&resMod, &copyd)) {
minus256(&resMod, &copyd, &resMod);
or256(&resDiv, &adder, &resDiv);
}
shiftr256(&copyd, 1, &copyd);
shiftr256(&adder, 1, &adder);
}
copy256(retDiv, &resDiv);
copy256(retMod, &resMod);
}
}
static void reverseString(char *str, uint32_t length) {
uint32_t i, j;
for (i = 0, j = length - 1; i < j; i++, j--) {
uint8_t c;
c = str[i];
str[i] = str[j];
str[j] = c;
}
}
bool tostring128(uint128_t *number, uint32_t baseParam, char *out,
uint32_t outLength) {
uint128_t rDiv;
uint128_t rMod;
uint128_t base;
copy128(&rDiv, number);
clear128(&rMod);
clear128(&base);
LOWER(base) = baseParam;
uint32_t offset = 0;
if ((baseParam < 2) || (baseParam > 16)) {
return false;
}
do {
if (offset > (outLength - 1)) {
return false;
}
divmod128(&rDiv, &base, &rDiv, &rMod);
out[offset++] = HEXDIGITS[(uint8_t)LOWER(rMod)];
} while (!zero128(&rDiv));
out[offset] = '\0';
reverseString(out, offset);
return true;
}
bool tostring256(uint256_t *number, uint32_t baseParam, char *out,
uint32_t outLength) {
uint256_t rDiv;
uint256_t rMod;
uint256_t base;
copy256(&rDiv, number);
clear256(&rMod);
clear256(&base);
UPPER(LOWER(base)) = 0;
LOWER(LOWER(base)) = baseParam;
uint32_t offset = 0;
if ((baseParam < 2) || (baseParam > 16)) {
return false;
}
do {
if (offset > (outLength - 1)) {
return false;
}
divmod256(&rDiv, &base, &rDiv, &rMod);
out[offset++] = HEXDIGITS[(uint8_t)LOWER(LOWER(rMod))];
} while (!zero256(&rDiv));
out[offset] = '\0';
reverseString(out, offset);
return true;
}
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