diff --git a/testing/web-platform/tests/compression/decompression-corrupt-input.any.js b/testing/web-platform/tests/compression/decompression-corrupt-input.any.js new file mode 100644 index 000000000000..95e91b662ee4 --- /dev/null +++ b/testing/web-platform/tests/compression/decompression-corrupt-input.any.js @@ -0,0 +1,299 @@ +// META global=worker + +// This test checks that DecompressionStream behaves according to the standard +// when the input is corrupted. To avoid a combinatorial explosion in the +// number of tests, we only mutate one field at a time, and we only test +// "interesting" values. + +'use strict'; + +// The many different cases are summarised in this data structure. +const expectations = [ + { + format: 'deflate', + + // Decompresses to 'expected output'. + baseInput: [120, 156, 75, 173, 40, 72, 77, 46, 73, 77, 81, 200, 47, 45, 41, + 40, 45, 1, 0, 48, 173, 6, 36], + + // See RFC1950 for the definition of the various fields used by deflate: + // https://tools.ietf.org/html/rfc1950. + fields: [ + { + // The function of this field. This matches the name used in the RFC. + name: 'CMF', + + // The offset of the field in bytes from the start of the input. + offset: 0, + + // The length of the field in bytes. + length: 1, + + cases: [ + { + // The value to set the field to. If the field contains multiple + // bytes, all the bytes will be set to this value. + value: 0, + + // The expected result. 'success' means the input is decoded + // successfully. 'error' means that the stream will be errored. + result: 'error' + } + ] + }, + { + name: 'FLG', + offset: 1, + length: 1, + + // FLG contains a 4-bit checksum (FCHECK) which is calculated in such a + // way that there are 4 valid values for this field. + cases: [ + { + value: 218, + result: 'success' + }, + { + value: 1, + result: 'success' + }, + { + value: 94, + result: 'success' + }, + { + // The remaining 252 values cause an error. + value: 157, + result: 'error' + } + ] + }, + { + name: 'DATA', + // In general, changing any bit of the data will trigger a checksum + // error. Only the last byte does anything else. + offset: 18, + length: 1, + cases: [ + { + value: 4, + result: 'success' + }, + { + value: 5, + result: 'error' + } + ] + }, + { + name: 'ADLER', + offset: -4, + length: 4, + cases: [ + { + value: 255, + result: 'error' + } + ] + } + ] + }, + { + format: 'gzip', + + // Decompresses to 'expected output'. + baseInput: [31, 139, 8, 0, 0, 0, 0, 0, 0, 3, 75, 173, 40, 72, 77, 46, 73, + 77, 81, 200, 47, 45, 41, 40, 45, 1, 0, 176, 1, 57, 179, 15, 0, + 0, 0], + + // See RFC1952 for the definition of the various fields used by gzip: + // https://tools.ietf.org/html/rfc1952. + fields: [ + { + name: 'ID', + offset: 0, + length: 2, + cases: [ + { + value: 255, + result: 'error' + } + ] + }, + { + name: 'CM', + offset: 2, + length: 1, + cases: [ + { + value: 0, + result: 'error' + } + ] + }, + { + name: 'FLG', + offset: 3, + length: 1, + cases: [ + { + value: 1, // FTEXT + result: 'success' + }, + { + value: 2, // FHCRC + result: 'error' + } + ] + }, + { + name: 'MTIME', + offset: 4, + length: 4, + cases: [ + { + // Any value is valid for this field. + value: 255, + result: 'success' + } + ] + }, + { + name: 'XFL', + offset: 8, + length: 1, + cases: [ + { + // Any value is accepted. + value: 255, + result: 'success' + } + ] + }, + { + name: 'OS', + offset: 9, + length: 1, + cases: [ + { + // Any value is accepted. + value: 128, + result: 'success' + } + ] + }, + { + name: 'DATA', + + // The last byte of the data is the most interesting. + offset: 26, + length: 1, + cases: [ + { + value: 3, + result: 'error' + }, + { + value: 4, + result: 'success' + } + ] + }, + { + name: 'CRC', + offset: -8, + length: 4, + cases: [ + { + // Any change will error the stream. + value: 0, + result: 'error' + } + ] + }, + { + name: 'ISIZE', + offset: -4, + length: 4, + cases: [ + { + // A mismatch will error the stream. + value: 1, + result: 'error' + } + ] + } + ] + } +]; + +async function tryDecompress(input, format) { + const ds = new DecompressionStream(format); + const reader = ds.readable.getReader(); + const writer = ds.writable.getWriter(); + writer.write(input).catch(() => {}); + writer.close().catch(() => {}); + let out = []; + while (true) { + try { + const { value, done } = await reader.read(); + if (done) { + break; + } + out = out.concat(Array.from(value)); + } catch (e) { + return { result: 'error' }; + } + } + const expectedOutput = 'expected output'; + if (out.length !== expectedOutput.length) { + return { result: 'corrupt' }; + } + for (let i = 0; i < out.length; ++i) { + if (out[i] !== expectedOutput.charCodeAt(i)) { + return { result: 'corrupt' }; + } + } + return { result: 'success' }; +} + +function corruptInput(input, offset, length, value) { + const output = new Uint8Array(input); + if (offset < 0) { + offset += input.length; + } + for (let i = offset; i < offset + length; ++i) { + output[i] = value; + } + return output; +} + +for (const { format, baseInput, fields } of expectations) { + promise_test(async () => { + const { result } = await tryDecompress(new Uint8Array(baseInput), format); + assert_equals(result, 'success', 'decompression should succeed'); + }, `the unchanged input for '${format}' should decompress successfully`); + + promise_test(async () => { + const truncatedInput = new Uint8Array(baseInput.slice(0, -1)); + const { result } = await tryDecompress(truncatedInput, format); + assert_equals(result, 'error', 'decompression should fail'); + }, `truncating the input for '${format}' should give an error`); + + promise_test(async () => { + const extendedInput = new Uint8Array(baseInput.concat([0])); + const { result } = await tryDecompress(extendedInput, format); + assert_equals(result, 'error', 'decompression should fail'); + }, `trailing junk for '${format}' should give an error`); + + for (const { name, offset, length, cases } of fields) { + for (const { value, result } of cases) { + promise_test(async () => { + const corruptedInput = corruptInput(baseInput, offset, length, value); + const { result: actual } = + await tryDecompress(corruptedInput, format); + assert_equals(actual, result, 'result should match'); + }, `format '${format}' field ${name} should be ${result} for ${value}`); + } + } +}