Add espaceJSON to String.sol (#5508)

Co-authored-by: Hadrien Croubois <hadrien.croubois@gmail.com>
Co-authored-by: Arr00 <13561405+arr00@users.noreply.github.com>
This commit is contained in:
Sambhav Jain
2025-03-03 20:01:43 +05:30
committed by GitHub
parent 3882a09163
commit fa995ef1fe
3 changed files with 57 additions and 0 deletions

View File

@ -15,6 +15,14 @@ library Strings {
bytes16 private constant HEX_DIGITS = "0123456789abcdef";
uint8 private constant ADDRESS_LENGTH = 20;
uint256 private constant SPECIAL_CHARS_LOOKUP =
(1 << 0x08) | // backspace
(1 << 0x09) | // tab
(1 << 0x0a) | // newline
(1 << 0x0c) | // form feed
(1 << 0x0d) | // carriage return
(1 << 0x22) | // double quote
(1 << 0x5c); // backslash
/**
* @dev The `value` string doesn't fit in the specified `length`.
@ -426,6 +434,43 @@ library Strings {
return value;
}
/**
* @dev Escape special characters in JSON strings. This can be useful to prevent JSON injection in NFT metadata.
*
* WARNING: This function should only be used in double quoted JSON strings. Single quotes are not escaped.
*/
function escapeJSON(string memory input) internal pure returns (string memory) {
bytes memory buffer = bytes(input);
bytes memory output = new bytes(2 * buffer.length); // worst case scenario
uint256 outputLength = 0;
for (uint256 i; i < buffer.length; ++i) {
bytes1 char = bytes1(_unsafeReadBytesOffset(buffer, i));
if (((SPECIAL_CHARS_LOOKUP & (1 << uint8(char))) != 0)) {
output[outputLength++] = "\\";
if (char == 0x08) output[outputLength++] = "b";
else if (char == 0x09) output[outputLength++] = "t";
else if (char == 0x0a) output[outputLength++] = "n";
else if (char == 0x0c) output[outputLength++] = "f";
else if (char == 0x0d) output[outputLength++] = "r";
else if (char == 0x5c) output[outputLength++] = "\\";
else if (char == 0x22) {
// solhint-disable-next-line quotes
output[outputLength++] = '"';
}
} else {
output[outputLength++] = char;
}
}
// write the actual length and deallocate unused memory
assembly ("memory-safe") {
mstore(output, outputLength)
mstore(0x40, add(output, shl(5, shr(5, add(outputLength, 63)))))
}
return string(output);
}
/**
* @dev Reads a bytes32 from a bytes array without bounds checking.
*