Differential D7059 Diff 23691 lib/utils/pkcs7-padding.js

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lib/utils/pkcs7-padding.js

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				// @flow

				import invariant from 'invariant';

				/**
				* PKCS#7 padding function for `Uint8Array` data.
				*
				* @param {Uint8Array} data - The data to be padded.
				* @param {number} blockSizeBytes - The block size in bytes.
				* @returns {Uint8Array} The padded data as a new Uint8Array.
				*/
				export function pkcs7pad(data: Uint8Array, blockSizeBytes: number): Uint8Array {
				ashoatUnsubmitted Not Done Inline Actions Nit: we don't use inline exports in the codebase except for Flow types and for files in `lib/types` (and other "types" files like that) Can you move these to be a single `export` declaration at the bottom of the file? ashoat: Nit: we don't use inline exports in the codebase except for Flow types and for files in…
				bartekAuthorUnsubmitted Done Inline Actions Sure, will do bartek: Sure, will do
				invariant(blockSizeBytes > 0, 'block size must be positive');
				invariant(blockSizeBytes < 256, 'block size must be less than 256');
				atulUnsubmitted Not Done Inline Actions Would it maybe make more sense to throw exceptions instead of using `invariant`? CC @ashoat atul: Would it maybe make more sense to throw exceptions instead of using `invariant`? CC @ashoat
				ashoatUnsubmitted Not Done Inline Actions I think `invariant` is good for "programmer error" type scenarios like this but I don't feel strongly. Ultimately `invariant` just throws an exception so it doesn't really matter ashoat: I think `invariant` is good for "programmer error" type scenarios like this but I don't feel…
				bartekAuthorUnsubmitted Done Inline Actions I'd stick to `invariant` because it looks clean. bartek: I'd stick to `invariant` because it looks clean.
				const padding = blockSizeBytes - (data.length % blockSizeBytes);
				const padded = new Uint8Array(data.length + padding);
				padded.set(data);
				padded.fill(padding, data.length);
				return padded;
				}

				/**
				* PKCS#7 unpadding function for `Uint8Array` data.
				*
				* @param {Uint8Array} data - The padded data to be unpadded.
				* @returns {Uint8Array} The unpadded data as a new Uint8Array.
				* @throws {Error} If the padding is invalid.
				*/
				export function pkcs7unpad(data: Uint8Array): Uint8Array {
				const padding = data[data.length - 1];
				invariant(padding > 0, 'padding must be positive');
				invariant(data.length >= padding, 'data length must be at least padding');
				invariant(
				data.subarray(data.length - padding).every(x => x === padding),
				'invalid padding',
				);

				const unpadded = data.subarray(0, data.length - padding);
				return unpadded;
				}