mirror of
https://github.com/ziglang/zig.git
synced 2024-11-16 17:15:37 +00:00
457 lines
17 KiB
Zig
457 lines
17 KiB
Zig
const std = @import("std.zig");
|
|
const assert = std.debug.assert;
|
|
const testing = std.testing;
|
|
const mem = std.mem;
|
|
|
|
pub const Error = error{
|
|
InvalidCharacter,
|
|
InvalidPadding,
|
|
NoSpaceLeft,
|
|
};
|
|
|
|
const decoderWithIgnoreProto = *const fn (ignore: []const u8) Base64DecoderWithIgnore;
|
|
|
|
/// Base64 codecs
|
|
pub const Codecs = struct {
|
|
alphabet_chars: [64]u8,
|
|
pad_char: ?u8,
|
|
decoderWithIgnore: decoderWithIgnoreProto,
|
|
Encoder: Base64Encoder,
|
|
Decoder: Base64Decoder,
|
|
};
|
|
|
|
pub const standard_alphabet_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".*;
|
|
fn standardBase64DecoderWithIgnore(ignore: []const u8) Base64DecoderWithIgnore {
|
|
return Base64DecoderWithIgnore.init(standard_alphabet_chars, '=', ignore);
|
|
}
|
|
|
|
/// Standard Base64 codecs, with padding
|
|
pub const standard = Codecs{
|
|
.alphabet_chars = standard_alphabet_chars,
|
|
.pad_char = '=',
|
|
.decoderWithIgnore = standardBase64DecoderWithIgnore,
|
|
.Encoder = Base64Encoder.init(standard_alphabet_chars, '='),
|
|
.Decoder = Base64Decoder.init(standard_alphabet_chars, '='),
|
|
};
|
|
|
|
/// Standard Base64 codecs, without padding
|
|
pub const standard_no_pad = Codecs{
|
|
.alphabet_chars = standard_alphabet_chars,
|
|
.pad_char = null,
|
|
.decoderWithIgnore = standardBase64DecoderWithIgnore,
|
|
.Encoder = Base64Encoder.init(standard_alphabet_chars, null),
|
|
.Decoder = Base64Decoder.init(standard_alphabet_chars, null),
|
|
};
|
|
|
|
pub const url_safe_alphabet_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_".*;
|
|
fn urlSafeBase64DecoderWithIgnore(ignore: []const u8) Base64DecoderWithIgnore {
|
|
return Base64DecoderWithIgnore.init(url_safe_alphabet_chars, null, ignore);
|
|
}
|
|
|
|
/// URL-safe Base64 codecs, with padding
|
|
pub const url_safe = Codecs{
|
|
.alphabet_chars = url_safe_alphabet_chars,
|
|
.pad_char = '=',
|
|
.decoderWithIgnore = urlSafeBase64DecoderWithIgnore,
|
|
.Encoder = Base64Encoder.init(url_safe_alphabet_chars, '='),
|
|
.Decoder = Base64Decoder.init(url_safe_alphabet_chars, '='),
|
|
};
|
|
|
|
/// URL-safe Base64 codecs, without padding
|
|
pub const url_safe_no_pad = Codecs{
|
|
.alphabet_chars = url_safe_alphabet_chars,
|
|
.pad_char = null,
|
|
.decoderWithIgnore = urlSafeBase64DecoderWithIgnore,
|
|
.Encoder = Base64Encoder.init(url_safe_alphabet_chars, null),
|
|
.Decoder = Base64Decoder.init(url_safe_alphabet_chars, null),
|
|
};
|
|
|
|
pub const Base64Encoder = struct {
|
|
alphabet_chars: [64]u8,
|
|
pad_char: ?u8,
|
|
|
|
/// A bunch of assertions, then simply pass the data right through.
|
|
pub fn init(alphabet_chars: [64]u8, pad_char: ?u8) Base64Encoder {
|
|
assert(alphabet_chars.len == 64);
|
|
var char_in_alphabet = [_]bool{false} ** 256;
|
|
for (alphabet_chars) |c| {
|
|
assert(!char_in_alphabet[c]);
|
|
assert(pad_char == null or c != pad_char.?);
|
|
char_in_alphabet[c] = true;
|
|
}
|
|
return Base64Encoder{
|
|
.alphabet_chars = alphabet_chars,
|
|
.pad_char = pad_char,
|
|
};
|
|
}
|
|
|
|
/// Compute the encoded length
|
|
pub fn calcSize(encoder: *const Base64Encoder, source_len: usize) usize {
|
|
if (encoder.pad_char != null) {
|
|
return @divTrunc(source_len + 2, 3) * 4;
|
|
} else {
|
|
const leftover = source_len % 3;
|
|
return @divTrunc(source_len, 3) * 4 + @divTrunc(leftover * 4 + 2, 3);
|
|
}
|
|
}
|
|
|
|
/// dest.len must at least be what you get from ::calcSize.
|
|
pub fn encode(encoder: *const Base64Encoder, dest: []u8, source: []const u8) []const u8 {
|
|
const out_len = encoder.calcSize(source.len);
|
|
assert(dest.len >= out_len);
|
|
|
|
var acc: u12 = 0;
|
|
var acc_len: u4 = 0;
|
|
var out_idx: usize = 0;
|
|
for (source) |v| {
|
|
acc = (acc << 8) + v;
|
|
acc_len += 8;
|
|
while (acc_len >= 6) {
|
|
acc_len -= 6;
|
|
dest[out_idx] = encoder.alphabet_chars[@truncate(u6, (acc >> acc_len))];
|
|
out_idx += 1;
|
|
}
|
|
}
|
|
if (acc_len > 0) {
|
|
dest[out_idx] = encoder.alphabet_chars[@truncate(u6, (acc << 6 - acc_len))];
|
|
out_idx += 1;
|
|
}
|
|
if (encoder.pad_char) |pad_char| {
|
|
for (dest[out_idx..out_len]) |*pad| {
|
|
pad.* = pad_char;
|
|
}
|
|
}
|
|
return dest[0..out_len];
|
|
}
|
|
};
|
|
|
|
pub const Base64Decoder = struct {
|
|
const invalid_char: u8 = 0xff;
|
|
|
|
/// e.g. 'A' => 0.
|
|
/// `invalid_char` for any value not in the 64 alphabet chars.
|
|
char_to_index: [256]u8,
|
|
pad_char: ?u8,
|
|
|
|
pub fn init(alphabet_chars: [64]u8, pad_char: ?u8) Base64Decoder {
|
|
var result = Base64Decoder{
|
|
.char_to_index = [_]u8{invalid_char} ** 256,
|
|
.pad_char = pad_char,
|
|
};
|
|
|
|
var char_in_alphabet = [_]bool{false} ** 256;
|
|
for (alphabet_chars, 0..) |c, i| {
|
|
assert(!char_in_alphabet[c]);
|
|
assert(pad_char == null or c != pad_char.?);
|
|
|
|
result.char_to_index[c] = @intCast(u8, i);
|
|
char_in_alphabet[c] = true;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// Return the maximum possible decoded size for a given input length - The actual length may be less if the input includes padding.
|
|
/// `InvalidPadding` is returned if the input length is not valid.
|
|
pub fn calcSizeUpperBound(decoder: *const Base64Decoder, source_len: usize) Error!usize {
|
|
var result = source_len / 4 * 3;
|
|
const leftover = source_len % 4;
|
|
if (decoder.pad_char != null) {
|
|
if (leftover % 4 != 0) return error.InvalidPadding;
|
|
} else {
|
|
if (leftover % 4 == 1) return error.InvalidPadding;
|
|
result += leftover * 3 / 4;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// Return the exact decoded size for a slice.
|
|
/// `InvalidPadding` is returned if the input length is not valid.
|
|
pub fn calcSizeForSlice(decoder: *const Base64Decoder, source: []const u8) Error!usize {
|
|
const source_len = source.len;
|
|
var result = try decoder.calcSizeUpperBound(source_len);
|
|
if (decoder.pad_char) |pad_char| {
|
|
if (source_len >= 1 and source[source_len - 1] == pad_char) result -= 1;
|
|
if (source_len >= 2 and source[source_len - 2] == pad_char) result -= 1;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// dest.len must be what you get from ::calcSize.
|
|
/// invalid characters result in error.InvalidCharacter.
|
|
/// invalid padding results in error.InvalidPadding.
|
|
pub fn decode(decoder: *const Base64Decoder, dest: []u8, source: []const u8) Error!void {
|
|
if (decoder.pad_char != null and source.len % 4 != 0) return error.InvalidPadding;
|
|
var acc: u12 = 0;
|
|
var acc_len: u4 = 0;
|
|
var dest_idx: usize = 0;
|
|
var leftover_idx: ?usize = null;
|
|
for (source, 0..) |c, src_idx| {
|
|
const d = decoder.char_to_index[c];
|
|
if (d == invalid_char) {
|
|
if (decoder.pad_char == null or c != decoder.pad_char.?) return error.InvalidCharacter;
|
|
leftover_idx = src_idx;
|
|
break;
|
|
}
|
|
acc = (acc << 6) + d;
|
|
acc_len += 6;
|
|
if (acc_len >= 8) {
|
|
acc_len -= 8;
|
|
dest[dest_idx] = @truncate(u8, acc >> acc_len);
|
|
dest_idx += 1;
|
|
}
|
|
}
|
|
if (acc_len > 4 or (acc & (@as(u12, 1) << acc_len) - 1) != 0) {
|
|
return error.InvalidPadding;
|
|
}
|
|
if (leftover_idx == null) return;
|
|
var leftover = source[leftover_idx.?..];
|
|
if (decoder.pad_char) |pad_char| {
|
|
const padding_len = acc_len / 2;
|
|
var padding_chars: usize = 0;
|
|
for (leftover) |c| {
|
|
if (c != pad_char) {
|
|
return if (c == Base64Decoder.invalid_char) error.InvalidCharacter else error.InvalidPadding;
|
|
}
|
|
padding_chars += 1;
|
|
}
|
|
if (padding_chars != padding_len) return error.InvalidPadding;
|
|
}
|
|
}
|
|
};
|
|
|
|
pub const Base64DecoderWithIgnore = struct {
|
|
decoder: Base64Decoder,
|
|
char_is_ignored: [256]bool,
|
|
|
|
pub fn init(alphabet_chars: [64]u8, pad_char: ?u8, ignore_chars: []const u8) Base64DecoderWithIgnore {
|
|
var result = Base64DecoderWithIgnore{
|
|
.decoder = Base64Decoder.init(alphabet_chars, pad_char),
|
|
.char_is_ignored = [_]bool{false} ** 256,
|
|
};
|
|
for (ignore_chars) |c| {
|
|
assert(result.decoder.char_to_index[c] == Base64Decoder.invalid_char);
|
|
assert(!result.char_is_ignored[c]);
|
|
assert(result.decoder.pad_char != c);
|
|
result.char_is_ignored[c] = true;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// Return the maximum possible decoded size for a given input length - The actual length may be less if the input includes padding
|
|
/// `InvalidPadding` is returned if the input length is not valid.
|
|
pub fn calcSizeUpperBound(decoder_with_ignore: *const Base64DecoderWithIgnore, source_len: usize) Error!usize {
|
|
var result = source_len / 4 * 3;
|
|
if (decoder_with_ignore.decoder.pad_char == null) {
|
|
const leftover = source_len % 4;
|
|
result += leftover * 3 / 4;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// Invalid characters that are not ignored result in error.InvalidCharacter.
|
|
/// Invalid padding results in error.InvalidPadding.
|
|
/// Decoding more data than can fit in dest results in error.NoSpaceLeft. See also ::calcSizeUpperBound.
|
|
/// Returns the number of bytes written to dest.
|
|
pub fn decode(decoder_with_ignore: *const Base64DecoderWithIgnore, dest: []u8, source: []const u8) Error!usize {
|
|
const decoder = &decoder_with_ignore.decoder;
|
|
var acc: u12 = 0;
|
|
var acc_len: u4 = 0;
|
|
var dest_idx: usize = 0;
|
|
var leftover_idx: ?usize = null;
|
|
for (source, 0..) |c, src_idx| {
|
|
if (decoder_with_ignore.char_is_ignored[c]) continue;
|
|
const d = decoder.char_to_index[c];
|
|
if (d == Base64Decoder.invalid_char) {
|
|
if (decoder.pad_char == null or c != decoder.pad_char.?) return error.InvalidCharacter;
|
|
leftover_idx = src_idx;
|
|
break;
|
|
}
|
|
acc = (acc << 6) + d;
|
|
acc_len += 6;
|
|
if (acc_len >= 8) {
|
|
if (dest_idx == dest.len) return error.NoSpaceLeft;
|
|
acc_len -= 8;
|
|
dest[dest_idx] = @truncate(u8, acc >> acc_len);
|
|
dest_idx += 1;
|
|
}
|
|
}
|
|
if (acc_len > 4 or (acc & (@as(u12, 1) << acc_len) - 1) != 0) {
|
|
return error.InvalidPadding;
|
|
}
|
|
const padding_len = acc_len / 2;
|
|
if (leftover_idx == null) {
|
|
if (decoder.pad_char != null and padding_len != 0) return error.InvalidPadding;
|
|
return dest_idx;
|
|
}
|
|
var leftover = source[leftover_idx.?..];
|
|
if (decoder.pad_char) |pad_char| {
|
|
var padding_chars: usize = 0;
|
|
for (leftover) |c| {
|
|
if (decoder_with_ignore.char_is_ignored[c]) continue;
|
|
if (c != pad_char) {
|
|
return if (c == Base64Decoder.invalid_char) error.InvalidCharacter else error.InvalidPadding;
|
|
}
|
|
padding_chars += 1;
|
|
}
|
|
if (padding_chars != padding_len) return error.InvalidPadding;
|
|
}
|
|
return dest_idx;
|
|
}
|
|
};
|
|
|
|
test "base64" {
|
|
@setEvalBranchQuota(8000);
|
|
try testBase64();
|
|
comptime try testAllApis(standard, "comptime", "Y29tcHRpbWU=");
|
|
}
|
|
|
|
test "base64 padding dest overflow" {
|
|
const input = "foo";
|
|
|
|
var expect: [128]u8 = undefined;
|
|
std.mem.set(u8, &expect, 0);
|
|
_ = url_safe.Encoder.encode(expect[0..url_safe.Encoder.calcSize(input.len)], input);
|
|
|
|
var got: [128]u8 = undefined;
|
|
std.mem.set(u8, &got, 0);
|
|
_ = url_safe.Encoder.encode(&got, input);
|
|
|
|
try std.testing.expectEqualSlices(u8, &expect, &got);
|
|
}
|
|
|
|
test "base64 url_safe_no_pad" {
|
|
@setEvalBranchQuota(8000);
|
|
try testBase64UrlSafeNoPad();
|
|
comptime try testAllApis(url_safe_no_pad, "comptime", "Y29tcHRpbWU");
|
|
}
|
|
|
|
fn testBase64() !void {
|
|
const codecs = standard;
|
|
|
|
try testAllApis(codecs, "", "");
|
|
try testAllApis(codecs, "f", "Zg==");
|
|
try testAllApis(codecs, "fo", "Zm8=");
|
|
try testAllApis(codecs, "foo", "Zm9v");
|
|
try testAllApis(codecs, "foob", "Zm9vYg==");
|
|
try testAllApis(codecs, "fooba", "Zm9vYmE=");
|
|
try testAllApis(codecs, "foobar", "Zm9vYmFy");
|
|
|
|
try testDecodeIgnoreSpace(codecs, "", " ");
|
|
try testDecodeIgnoreSpace(codecs, "f", "Z g= =");
|
|
try testDecodeIgnoreSpace(codecs, "fo", " Zm8=");
|
|
try testDecodeIgnoreSpace(codecs, "foo", "Zm9v ");
|
|
try testDecodeIgnoreSpace(codecs, "foob", "Zm9vYg = = ");
|
|
try testDecodeIgnoreSpace(codecs, "fooba", "Zm9v YmE=");
|
|
try testDecodeIgnoreSpace(codecs, "foobar", " Z m 9 v Y m F y ");
|
|
|
|
// test getting some api errors
|
|
try testError(codecs, "A", error.InvalidPadding);
|
|
try testError(codecs, "AA", error.InvalidPadding);
|
|
try testError(codecs, "AAA", error.InvalidPadding);
|
|
try testError(codecs, "A..A", error.InvalidCharacter);
|
|
try testError(codecs, "AA=A", error.InvalidPadding);
|
|
try testError(codecs, "AA/=", error.InvalidPadding);
|
|
try testError(codecs, "A/==", error.InvalidPadding);
|
|
try testError(codecs, "A===", error.InvalidPadding);
|
|
try testError(codecs, "====", error.InvalidPadding);
|
|
|
|
try testNoSpaceLeftError(codecs, "AA==");
|
|
try testNoSpaceLeftError(codecs, "AAA=");
|
|
try testNoSpaceLeftError(codecs, "AAAA");
|
|
try testNoSpaceLeftError(codecs, "AAAAAA==");
|
|
}
|
|
|
|
fn testBase64UrlSafeNoPad() !void {
|
|
const codecs = url_safe_no_pad;
|
|
|
|
try testAllApis(codecs, "", "");
|
|
try testAllApis(codecs, "f", "Zg");
|
|
try testAllApis(codecs, "fo", "Zm8");
|
|
try testAllApis(codecs, "foo", "Zm9v");
|
|
try testAllApis(codecs, "foob", "Zm9vYg");
|
|
try testAllApis(codecs, "fooba", "Zm9vYmE");
|
|
try testAllApis(codecs, "foobar", "Zm9vYmFy");
|
|
|
|
try testDecodeIgnoreSpace(codecs, "", " ");
|
|
try testDecodeIgnoreSpace(codecs, "f", "Z g ");
|
|
try testDecodeIgnoreSpace(codecs, "fo", " Zm8");
|
|
try testDecodeIgnoreSpace(codecs, "foo", "Zm9v ");
|
|
try testDecodeIgnoreSpace(codecs, "foob", "Zm9vYg ");
|
|
try testDecodeIgnoreSpace(codecs, "fooba", "Zm9v YmE");
|
|
try testDecodeIgnoreSpace(codecs, "foobar", " Z m 9 v Y m F y ");
|
|
|
|
// test getting some api errors
|
|
try testError(codecs, "A", error.InvalidPadding);
|
|
try testError(codecs, "AAA=", error.InvalidCharacter);
|
|
try testError(codecs, "A..A", error.InvalidCharacter);
|
|
try testError(codecs, "AA=A", error.InvalidCharacter);
|
|
try testError(codecs, "AA/=", error.InvalidCharacter);
|
|
try testError(codecs, "A/==", error.InvalidCharacter);
|
|
try testError(codecs, "A===", error.InvalidCharacter);
|
|
try testError(codecs, "====", error.InvalidCharacter);
|
|
|
|
try testNoSpaceLeftError(codecs, "AA");
|
|
try testNoSpaceLeftError(codecs, "AAA");
|
|
try testNoSpaceLeftError(codecs, "AAAA");
|
|
try testNoSpaceLeftError(codecs, "AAAAAA");
|
|
}
|
|
|
|
fn testAllApis(codecs: Codecs, expected_decoded: []const u8, expected_encoded: []const u8) !void {
|
|
// Base64Encoder
|
|
{
|
|
var buffer: [0x100]u8 = undefined;
|
|
const encoded = codecs.Encoder.encode(&buffer, expected_decoded);
|
|
try testing.expectEqualSlices(u8, expected_encoded, encoded);
|
|
}
|
|
|
|
// Base64Decoder
|
|
{
|
|
var buffer: [0x100]u8 = undefined;
|
|
var decoded = buffer[0..try codecs.Decoder.calcSizeForSlice(expected_encoded)];
|
|
try codecs.Decoder.decode(decoded, expected_encoded);
|
|
try testing.expectEqualSlices(u8, expected_decoded, decoded);
|
|
}
|
|
|
|
// Base64DecoderWithIgnore
|
|
{
|
|
const decoder_ignore_nothing = codecs.decoderWithIgnore("");
|
|
var buffer: [0x100]u8 = undefined;
|
|
var decoded = buffer[0..try decoder_ignore_nothing.calcSizeUpperBound(expected_encoded.len)];
|
|
var written = try decoder_ignore_nothing.decode(decoded, expected_encoded);
|
|
try testing.expect(written <= decoded.len);
|
|
try testing.expectEqualSlices(u8, expected_decoded, decoded[0..written]);
|
|
}
|
|
}
|
|
|
|
fn testDecodeIgnoreSpace(codecs: Codecs, expected_decoded: []const u8, encoded: []const u8) !void {
|
|
const decoder_ignore_space = codecs.decoderWithIgnore(" ");
|
|
var buffer: [0x100]u8 = undefined;
|
|
var decoded = buffer[0..try decoder_ignore_space.calcSizeUpperBound(encoded.len)];
|
|
var written = try decoder_ignore_space.decode(decoded, encoded);
|
|
try testing.expectEqualSlices(u8, expected_decoded, decoded[0..written]);
|
|
}
|
|
|
|
fn testError(codecs: Codecs, encoded: []const u8, expected_err: anyerror) !void {
|
|
const decoder_ignore_space = codecs.decoderWithIgnore(" ");
|
|
var buffer: [0x100]u8 = undefined;
|
|
if (codecs.Decoder.calcSizeForSlice(encoded)) |decoded_size| {
|
|
var decoded = buffer[0..decoded_size];
|
|
if (codecs.Decoder.decode(decoded, encoded)) |_| {
|
|
return error.ExpectedError;
|
|
} else |err| if (err != expected_err) return err;
|
|
} else |err| if (err != expected_err) return err;
|
|
|
|
if (decoder_ignore_space.decode(buffer[0..], encoded)) |_| {
|
|
return error.ExpectedError;
|
|
} else |err| if (err != expected_err) return err;
|
|
}
|
|
|
|
fn testNoSpaceLeftError(codecs: Codecs, encoded: []const u8) !void {
|
|
const decoder_ignore_space = codecs.decoderWithIgnore(" ");
|
|
var buffer: [0x100]u8 = undefined;
|
|
var decoded = buffer[0 .. (try codecs.Decoder.calcSizeForSlice(encoded)) - 1];
|
|
if (decoder_ignore_space.decode(decoded, encoded)) |_| {
|
|
return error.ExpectedError;
|
|
} else |err| if (err != error.NoSpaceLeft) return err;
|
|
}
|