Commit fbe7d8c1cb
Changed files (1)
lib
std
crypto
lib/std/crypto/chacha20.zig
@@ -7,6 +7,7 @@ const assert = std.debug.assert;
const testing = std.testing;
const builtin = @import("builtin");
const maxInt = std.math.maxInt;
+const Poly1305 = std.crypto.Poly1305;
const QuarterRound = struct {
a: usize,
@@ -434,3 +435,196 @@ test "crypto.chacha20 test vector 5" {
chaCha20With64BitNonce(result[0..], input[0..], 0, key, nonce);
testing.expectEqualSlices(u8, &expected_result, &result);
}
+
+pub const chacha20poly1305_tag_size = 16;
+
+pub fn chacha20poly1305Seal(dst: []u8, plaintext: []const u8, data: []const u8, key: [32]u8, nonce: [12]u8) void {
+ assert(dst.len >= plaintext.len + chacha20poly1305_tag_size);
+
+ // derive poly1305 key
+ var polyKey = [_]u8{0} ** 32;
+ chaCha20IETF(polyKey[0..], polyKey[0..], 0, key, nonce);
+
+ // encrypt plaintext
+ chaCha20IETF(dst[0..plaintext.len], plaintext, 1, key, nonce);
+
+ // construct mac
+ var mac = Poly1305.init(polyKey[0..]);
+ mac.update(data);
+ if (data.len % 16 != 0) {
+ const zeros = [_]u8{0} ** 16;
+ const padding = 16 - (data.len % 16);
+ mac.update(zeros[0..padding]);
+ }
+ mac.update(dst[0..plaintext.len]);
+ if (plaintext.len % 16 != 0) {
+ const zeros = [_]u8{0} ** 16;
+ const padding = 16 - (plaintext.len % 16);
+ mac.update(zeros[0..padding]);
+ }
+ var lens: [16]u8 = undefined;
+ mem.writeIntSliceLittle(u64, lens[0..8], data.len);
+ mem.writeIntSliceLittle(u64, lens[8..16], plaintext.len);
+ mac.update(lens[0..]);
+ mac.final(dst[plaintext.len..]);
+}
+
+pub fn chacha20poly1305Open(dst: []u8, ciphertext: []const u8, data: []const u8, key: [32]u8, nonce: [12]u8) bool {
+ assert(ciphertext.len >= chacha20poly1305_tag_size);
+ assert(dst.len >= ciphertext.len - chacha20poly1305_tag_size);
+
+ // split ciphertext and tag
+ var polyTag = ciphertext[ciphertext.len - chacha20poly1305_tag_size ..];
+ ciphertext = ciphertext[0 .. ciphertext.len - chacha20poly1305_tag_size];
+
+ // derive poly1305 key
+ var polyKey = [_]u8{0} ** 32;
+ chaCha20IETF(polyKey[0..], polyKey[0..], 0, key, nonce);
+
+ // construct mac
+ var mac = Poly1305.init(polyKey[0..]);
+
+ mac.update(data);
+ if (data.len % 16 != 0) {
+ const zeros = [_]u8{0} ** 16;
+ const padding = 16 - (data.len % 16);
+ mac.update(zeros[0..padding]);
+ }
+ mac.update(ciphertext);
+ if (ciphertext.len % 16 != 0) {
+ const zeros = [_]u8{0} ** 16;
+ const padding = 16 - (ciphertext.len % 16);
+ mac.update(zeros[0..padding]);
+ }
+ var lens: [16]u8 = undefined;
+ mem.writeIntSliceLittle(u64, lens[0..8], data.len);
+ mem.writeIntSliceLittle(u64, lens[8..16], ciphertext.len);
+ mac.update(lens[0..]);
+ var computedTag: [16]u8 = undefined;
+ mac.final(computedTag[0..]);
+
+ // verify mac
+ if (!mem.eql(u8, polyTag, computedTag[0..])) {
+ return false;
+ }
+
+ // decrypt ciphertext
+ chaCha20IETF(dst[0..ciphertext.len], ciphertext, 1, key, nonce);
+ return true;
+}
+
+test "seal" {
+ {
+ const plaintext = "";
+ const data = "";
+ const key = [_]u8{
+ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+ 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+ };
+ const nonce = [_]u8{ 0x7, 0x0, 0x0, 0x0, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 };
+ const exp_out = [_]u8{ 0xa0, 0x78, 0x4d, 0x7a, 0x47, 0x16, 0xf3, 0xfe, 0xb4, 0xf6, 0x4e, 0x7f, 0x4b, 0x39, 0xbf, 0x4 };
+
+ var out: [exp_out.len]u8 = undefined;
+ chacha20poly1305Seal(out[0..], plaintext, data, key, nonce);
+ testing.expectEqualSlices(u8, exp_out, out);
+ }
+ {
+ const plaintext = [_]u8{
+ 0x4c, 0x61, 0x64, 0x69, 0x65, 0x73, 0x20, 0x61, 0x6e, 0x64, 0x20, 0x47, 0x65, 0x6e, 0x74, 0x6c,
+ 0x65, 0x6d, 0x65, 0x6e, 0x20, 0x6f, 0x66, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x61, 0x73,
+ 0x73, 0x20, 0x6f, 0x66, 0x20, 0x27, 0x39, 0x39, 0x3a, 0x20, 0x49, 0x66, 0x20, 0x49, 0x20, 0x63,
+ 0x6f, 0x75, 0x6c, 0x64, 0x20, 0x6f, 0x66, 0x66, 0x65, 0x72, 0x20, 0x79, 0x6f, 0x75, 0x20, 0x6f,
+ 0x6e, 0x6c, 0x79, 0x20, 0x6f, 0x6e, 0x65, 0x20, 0x74, 0x69, 0x70, 0x20, 0x66, 0x6f, 0x72, 0x20,
+ 0x74, 0x68, 0x65, 0x20, 0x66, 0x75, 0x74, 0x75, 0x72, 0x65, 0x2c, 0x20, 0x73, 0x75, 0x6e, 0x73,
+ 0x63, 0x72, 0x65, 0x65, 0x6e, 0x20, 0x77, 0x6f, 0x75, 0x6c, 0x64, 0x20, 0x62, 0x65, 0x20, 0x69,
+ 0x74, 0x2e,
+ };
+ const data = [_]u8{ 0x50, 0x51, 0x52, 0x53, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7 };
+ const key = [_]u8{
+ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+ 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+ };
+ const nonce = [_]u8{ 0x7, 0x0, 0x0, 0x0, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 };
+ const exp_out = [_]u8{
+ 0xd3, 0x1a, 0x8d, 0x34, 0x64, 0x8e, 0x60, 0xdb, 0x7b, 0x86, 0xaf, 0xbc, 0x53, 0xef, 0x7e, 0xc2,
+ 0xa4, 0xad, 0xed, 0x51, 0x29, 0x6e, 0x8, 0xfe, 0xa9, 0xe2, 0xb5, 0xa7, 0x36, 0xee, 0x62, 0xd6,
+ 0x3d, 0xbe, 0xa4, 0x5e, 0x8c, 0xa9, 0x67, 0x12, 0x82, 0xfa, 0xfb, 0x69, 0xda, 0x92, 0x72, 0x8b,
+ 0x1a, 0x71, 0xde, 0xa, 0x9e, 0x6, 0xb, 0x29, 0x5, 0xd6, 0xa5, 0xb6, 0x7e, 0xcd, 0x3b, 0x36,
+ 0x92, 0xdd, 0xbd, 0x7f, 0x2d, 0x77, 0x8b, 0x8c, 0x98, 0x3, 0xae, 0xe3, 0x28, 0x9, 0x1b, 0x58,
+ 0xfa, 0xb3, 0x24, 0xe4, 0xfa, 0xd6, 0x75, 0x94, 0x55, 0x85, 0x80, 0x8b, 0x48, 0x31, 0xd7, 0xbc,
+ 0x3f, 0xf4, 0xde, 0xf0, 0x8e, 0x4b, 0x7a, 0x9d, 0xe5, 0x76, 0xd2, 0x65, 0x86, 0xce, 0xc6, 0x4b,
+ 0x61, 0x16, 0x1a, 0xe1, 0xb, 0x59, 0x4f, 0x9, 0xe2, 0x6a, 0x7e, 0x90, 0x2e, 0xcb, 0xd0, 0x60,
+ 0x6, 0x91,
+ };
+
+ var out: [exp_out.len]u8 = undefined;
+ chacha20poly1305Seal(out[0..], plaintext[0..], data[0..], key, nonce);
+ testing.expectEqualSlices(u8, exp_out, out);
+ }
+}
+
+test "open" {
+ {
+ const ciphertext = [_]u8{ 0xa0, 0x78, 0x4d, 0x7a, 0x47, 0x16, 0xf3, 0xfe, 0xb4, 0xf6, 0x4e, 0x7f, 0x4b, 0x39, 0xbf, 0x4 };
+ const data = "";
+ const key = [_]u8{
+ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+ 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+ };
+ const nonce = [_]u8{ 0x7, 0x0, 0x0, 0x0, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 };
+ const exp_out = "";
+
+ var out: [exp_out.len]u8 = undefined;
+ var valid: bool = chacha20poly1305Open(out[0..], ciphertext[0..], data, key, nonce);
+ testing.expect(valid);
+ testing.expectEqualSlices(u8, exp_out, out);
+ }
+ {
+ const ciphertext = [_]u8{
+ 0xd3, 0x1a, 0x8d, 0x34, 0x64, 0x8e, 0x60, 0xdb, 0x7b, 0x86, 0xaf, 0xbc, 0x53, 0xef, 0x7e, 0xc2,
+ 0xa4, 0xad, 0xed, 0x51, 0x29, 0x6e, 0x8, 0xfe, 0xa9, 0xe2, 0xb5, 0xa7, 0x36, 0xee, 0x62, 0xd6,
+ 0x3d, 0xbe, 0xa4, 0x5e, 0x8c, 0xa9, 0x67, 0x12, 0x82, 0xfa, 0xfb, 0x69, 0xda, 0x92, 0x72, 0x8b,
+ 0x1a, 0x71, 0xde, 0xa, 0x9e, 0x6, 0xb, 0x29, 0x5, 0xd6, 0xa5, 0xb6, 0x7e, 0xcd, 0x3b, 0x36,
+ 0x92, 0xdd, 0xbd, 0x7f, 0x2d, 0x77, 0x8b, 0x8c, 0x98, 0x3, 0xae, 0xe3, 0x28, 0x9, 0x1b, 0x58,
+ 0xfa, 0xb3, 0x24, 0xe4, 0xfa, 0xd6, 0x75, 0x94, 0x55, 0x85, 0x80, 0x8b, 0x48, 0x31, 0xd7, 0xbc,
+ 0x3f, 0xf4, 0xde, 0xf0, 0x8e, 0x4b, 0x7a, 0x9d, 0xe5, 0x76, 0xd2, 0x65, 0x86, 0xce, 0xc6, 0x4b,
+ 0x61, 0x16, 0x1a, 0xe1, 0xb, 0x59, 0x4f, 0x9, 0xe2, 0x6a, 0x7e, 0x90, 0x2e, 0xcb, 0xd0, 0x60,
+ 0x6, 0x91,
+ };
+ const data = [_]u8{ 0x50, 0x51, 0x52, 0x53, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7 };
+ const key = [_]u8{
+ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+ 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+ };
+ const nonce = [_]u8{ 0x7, 0x0, 0x0, 0x0, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 };
+ const exp_out = [_]u8{
+ 0x4c, 0x61, 0x64, 0x69, 0x65, 0x73, 0x20, 0x61, 0x6e, 0x64, 0x20, 0x47, 0x65, 0x6e, 0x74, 0x6c,
+ 0x65, 0x6d, 0x65, 0x6e, 0x20, 0x6f, 0x66, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x61, 0x73,
+ 0x73, 0x20, 0x6f, 0x66, 0x20, 0x27, 0x39, 0x39, 0x3a, 0x20, 0x49, 0x66, 0x20, 0x49, 0x20, 0x63,
+ 0x6f, 0x75, 0x6c, 0x64, 0x20, 0x6f, 0x66, 0x66, 0x65, 0x72, 0x20, 0x79, 0x6f, 0x75, 0x20, 0x6f,
+ 0x6e, 0x6c, 0x79, 0x20, 0x6f, 0x6e, 0x65, 0x20, 0x74, 0x69, 0x70, 0x20, 0x66, 0x6f, 0x72, 0x20,
+ 0x74, 0x68, 0x65, 0x20, 0x66, 0x75, 0x74, 0x75, 0x72, 0x65, 0x2c, 0x20, 0x73, 0x75, 0x6e, 0x73,
+ 0x63, 0x72, 0x65, 0x65, 0x6e, 0x20, 0x77, 0x6f, 0x75, 0x6c, 0x64, 0x20, 0x62, 0x65, 0x20, 0x69,
+ 0x74, 0x2e,
+ };
+
+ var out: [exp_out.len]u8 = undefined;
+ var valid: bool = chacha20poly1305Open(out[0..], ciphertext[0..], data[0..], key, nonce);
+ testing.expect(valid);
+ testing.expectEqualSlices(u8, exp_out, out);
+
+ // corrupting the ciphertext, data, key, or nonce should cause a failure
+ var bad_ciphertext = ciphertext;
+ bad_ciphertext[0] ^= 1;
+ testing.expect(!chacha20poly1305Open(out[0..], bad_ciphertext[0..], data, key, nonce));
+ var bad_data = data;
+ bad_data[0] ^= 1;
+ testing.expect(!chacha20poly1305Open(out[0..], ciphertext[0..], bad_data, key, nonce));
+ var bad_key = key;
+ bad_key[0] ^= 1;
+ testing.expect(!chacha20poly1305Open(out[0..], ciphertext[0..], data, bad_key, nonce));
+ var bad_nonce = nonce;
+ bad_nonce[0] ^= 1;
+ testing.expect(!chacha20poly1305Open(out[0..], ciphertext[0..], data, key, bad_nonce));
+ }
+}