Commit bb1c6bc376

Frank Denis <github@pureftpd.org>
2020-09-28 14:50:00
Add AEGIS-256 as well
1 parent 9f274e1
Changed files (3)
lib/std/crypto/aegis.zig
@@ -3,10 +3,10 @@ const mem = std.mem;
 const assert = std.debug.assert;
 const AESBlock = std.crypto.core.aes.Block;
 
-const State = struct {
+const State128L = struct {
     blocks: [8]AESBlock,
 
-    fn init(key: [16]u8, nonce: [16]u8) State {
+    fn init(key: [16]u8, nonce: [16]u8) State128L {
         const c1 = AESBlock.fromBytes(&[16]u8{ 0xdb, 0x3d, 0x18, 0x55, 0x6d, 0xc2, 0x2f, 0xf1, 0x20, 0x11, 0x31, 0x42, 0x73, 0xb5, 0x28, 0xdd });
         const c2 = AESBlock.fromBytes(&[16]u8{ 0x0, 0x1, 0x01, 0x02, 0x03, 0x05, 0x08, 0x0d, 0x15, 0x22, 0x37, 0x59, 0x90, 0xe9, 0x79, 0x62 });
         const key_block = AESBlock.fromBytes(&key);
@@ -21,7 +21,7 @@ const State = struct {
             key_block.xorBlocks(c1),
             key_block.xorBlocks(c2),
         };
-        var state = State{ .blocks = blocks };
+        var state = State128L{ .blocks = blocks };
         var i: usize = 0;
         while (i < 10) : (i += 1) {
             state.update(nonce_block, key_block);
@@ -29,7 +29,7 @@ const State = struct {
         return state;
     }
 
-    inline fn update(state: *State, d1: AESBlock, d2: AESBlock) void {
+    inline fn update(state: *State128L, d1: AESBlock, d2: AESBlock) void {
         const blocks = &state.blocks;
         const tmp = blocks[7];
         comptime var i: usize = 7;
@@ -41,7 +41,7 @@ const State = struct {
         blocks[4] = blocks[4].xorBlocks(d2);
     }
 
-    fn enc(state: *State, dst: []u8, src: []const u8) void {
+    fn enc(state: *State128L, dst: *[32]u8, src: *const [32]u8) void {
         const blocks = &state.blocks;
         const msg0 = AESBlock.fromBytes(src[0..16]);
         const msg1 = AESBlock.fromBytes(src[16..32]);
@@ -54,7 +54,7 @@ const State = struct {
         state.update(msg0, msg1);
     }
 
-    fn dec(state: *State, dst: []u8, src: []const u8) void {
+    fn dec(state: *State128L, dst: *[32]u8, src: *const [32]u8) void {
         const blocks = &state.blocks;
         var msg0 = AESBlock.fromBytes(src[0..16]).xorBlocks(blocks[6]).xorBlocks(blocks[1]);
         var msg1 = AESBlock.fromBytes(src[16..32]).xorBlocks(blocks[2]).xorBlocks(blocks[5]);
@@ -65,7 +65,7 @@ const State = struct {
         state.update(msg0, msg1);
     }
 
-    fn mac(state: *State, adlen: usize, mlen: usize) [16]u8 {
+    fn mac(state: *State128L, adlen: usize, mlen: usize) [16]u8 {
         const blocks = &state.blocks;
         var sizes: [16]u8 = undefined;
         mem.writeIntLittle(u64, sizes[0..8], adlen * 8);
@@ -99,7 +99,7 @@ pub const AEGIS128L = struct {
     /// k: private key
     pub fn encrypt(c: []u8, tag: *[tag_length]u8, m: []const u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) void {
         assert(c.len == m.len);
-        var state = State.init(key, npub);
+        var state = State128L.init(key, npub);
         var src: [32]u8 align(16) = undefined;
         var dst: [32]u8 align(16) = undefined;
         var i: usize = 0;
@@ -132,7 +132,7 @@ pub const AEGIS128L = struct {
     /// k: private key
     pub fn decrypt(m: []u8, c: []const u8, tag: [tag_length]u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) !void {
         assert(c.len == m.len);
-        var state = State.init(key, npub);
+        var state = State128L.init(key, npub);
         var src: [32]u8 align(16) = undefined;
         var dst: [32]u8 align(16) = undefined;
         var i: usize = 0;
@@ -170,10 +170,171 @@ pub const AEGIS128L = struct {
     }
 };
 
+const State256 = struct {
+    blocks: [6]AESBlock,
+
+    fn init(key: [32]u8, nonce: [32]u8) State256 {
+        const c1 = AESBlock.fromBytes(&[16]u8{ 0xdb, 0x3d, 0x18, 0x55, 0x6d, 0xc2, 0x2f, 0xf1, 0x20, 0x11, 0x31, 0x42, 0x73, 0xb5, 0x28, 0xdd });
+        const c2 = AESBlock.fromBytes(&[16]u8{ 0x0, 0x1, 0x01, 0x02, 0x03, 0x05, 0x08, 0x0d, 0x15, 0x22, 0x37, 0x59, 0x90, 0xe9, 0x79, 0x62 });
+        const key_block1 = AESBlock.fromBytes(key[0..16]);
+        const key_block2 = AESBlock.fromBytes(key[16..32]);
+        const nonce_block1 = AESBlock.fromBytes(nonce[0..16]);
+        const nonce_block2 = AESBlock.fromBytes(nonce[16..32]);
+        const kxn1 = key_block1.xorBlocks(nonce_block1);
+        const kxn2 = key_block2.xorBlocks(nonce_block2);
+        const blocks = [6]AESBlock{
+            kxn1,
+            kxn2,
+            c1,
+            c2,
+            key_block1.xorBlocks(c2),
+            key_block2.xorBlocks(c1),
+        };
+        var state = State256{ .blocks = blocks };
+        var i: usize = 0;
+        while (i < 4) : (i += 1) {
+            state.update(key_block1);
+            state.update(key_block2);
+            state.update(kxn1);
+            state.update(kxn2);
+        }
+        return state;
+    }
+
+    inline fn update(state: *State256, d: AESBlock) void {
+        const blocks = &state.blocks;
+        const tmp = blocks[5].encrypt(blocks[0]);
+        comptime var i: usize = 5;
+        inline while (i > 0) : (i -= 1) {
+            blocks[i] = blocks[i - 1].encrypt(blocks[i]);
+        }
+        blocks[0] = tmp.xorBlocks(d);
+    }
+
+    fn enc(state: *State256, dst: *[16]u8, src: *const [16]u8) void {
+        const blocks = &state.blocks;
+        const msg = AESBlock.fromBytes(src);
+        var tmp = msg.xorBlocks(blocks[5]).xorBlocks(blocks[4]).xorBlocks(blocks[1]);
+        tmp = tmp.xorBlocks(blocks[2].andBlocks(blocks[3]));
+        dst.* = tmp.toBytes();
+        state.update(msg);
+    }
+
+    fn dec(state: *State256, dst: *[16]u8, src: *const [16]u8) void {
+        const blocks = &state.blocks;
+        var msg = AESBlock.fromBytes(src).xorBlocks(blocks[5]).xorBlocks(blocks[4]).xorBlocks(blocks[1]);
+        msg = msg.xorBlocks(blocks[2].andBlocks(blocks[3]));
+        dst.* = msg.toBytes();
+        state.update(msg);
+    }
+
+    fn mac(state: *State256, adlen: usize, mlen: usize) [16]u8 {
+        const blocks = &state.blocks;
+        var sizes: [16]u8 = undefined;
+        mem.writeIntLittle(u64, sizes[0..8], adlen * 8);
+        mem.writeIntLittle(u64, sizes[8..16], mlen * 8);
+        const tmp = AESBlock.fromBytes(&sizes).xorBlocks(blocks[3]);
+        var i: usize = 0;
+        while (i < 7) : (i += 1) {
+            state.update(tmp);
+        }
+        return blocks[0].xorBlocks(blocks[1]).xorBlocks(blocks[2]).xorBlocks(blocks[3]).xorBlocks(blocks[4]).
+            xorBlocks(blocks[5]).toBytes();
+    }
+};
+
+/// AEGIS is a very fast authenticated encryption system built on top of the core AES function.
+///
+/// The 256 bit variant of AEGIS has a 256 bit key, a 256 bit nonce, and processes 128 bit message blocks.
+///
+/// https://eprint.iacr.org/2013/695.pdf
+pub const AEGIS256 = struct {
+    pub const tag_length = 16;
+    pub const nonce_length = 32;
+    pub const key_length = 32;
+
+    /// c: ciphertext: output buffer should be of size m.len
+    /// tag: authentication tag: output MAC
+    /// m: message
+    /// ad: Associated Data
+    /// npub: public nonce
+    /// k: private key
+    pub fn encrypt(c: []u8, tag: *[tag_length]u8, m: []const u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) void {
+        assert(c.len == m.len);
+        var state = State256.init(key, npub);
+        var src: [16]u8 align(16) = undefined;
+        var dst: [16]u8 align(16) = undefined;
+        var i: usize = 0;
+        while (i + 16 <= ad.len) : (i += 16) {
+            state.enc(&dst, ad[i..][0..16]);
+        }
+        if (ad.len % 16 != 0) {
+            mem.set(u8, src[0..], 0);
+            mem.copy(u8, src[0 .. ad.len % 16], ad[i .. i + ad.len % 16]);
+            state.enc(&dst, &src);
+        }
+        i = 0;
+        while (i + 16 <= m.len) : (i += 16) {
+            state.enc(c[i..][0..16], m[i..][0..16]);
+        }
+        if (m.len % 16 != 0) {
+            mem.set(u8, src[0..], 0);
+            mem.copy(u8, src[0 .. m.len % 16], m[i .. i + m.len % 16]);
+            state.enc(&dst, &src);
+            mem.copy(u8, c[i .. i + m.len % 16], dst[0 .. m.len % 16]);
+        }
+        tag.* = state.mac(ad.len, m.len);
+    }
+
+    /// m: message: output buffer should be of size c.len
+    /// c: ciphertext
+    /// tag: authentication tag
+    /// ad: Associated Data
+    /// npub: public nonce
+    /// k: private key
+    pub fn decrypt(m: []u8, c: []const u8, tag: [tag_length]u8, ad: []const u8, npub: [nonce_length]u8, key: [key_length]u8) !void {
+        assert(c.len == m.len);
+        var state = State256.init(key, npub);
+        var src: [16]u8 align(16) = undefined;
+        var dst: [16]u8 align(16) = undefined;
+        var i: usize = 0;
+        while (i + 16 <= ad.len) : (i += 16) {
+            state.enc(&dst, ad[i..][0..16]);
+        }
+        if (ad.len % 16 != 0) {
+            mem.set(u8, src[0..], 0);
+            mem.copy(u8, src[0 .. ad.len % 16], ad[i .. i + ad.len % 16]);
+            state.enc(&dst, &src);
+        }
+        i = 0;
+        while (i + 16 <= m.len) : (i += 16) {
+            state.dec(m[i..][0..16], c[i..][0..16]);
+        }
+        if (m.len % 16 != 0) {
+            mem.set(u8, src[0..], 0);
+            mem.copy(u8, src[0 .. m.len % 16], c[i .. i + m.len % 16]);
+            state.dec(&dst, &src);
+            mem.copy(u8, m[i .. i + m.len % 16], dst[0 .. m.len % 16]);
+            mem.set(u8, dst[0 .. m.len % 16], 0);
+            const blocks = &state.blocks;
+            blocks[0] = blocks[0].xorBlocks(AESBlock.fromBytes(&dst));
+        }
+        const computed_tag = state.mac(ad.len, m.len);
+        var acc: u8 = 0;
+        for (computed_tag) |_, j| {
+            acc |= (computed_tag[j] ^ tag[j]);
+        }
+        if (acc != 0) {
+            mem.set(u8, m, 0xaa);
+            return error.AuthenticationFailed;
+        }
+    }
+};
+
 const htest = @import("test.zig");
 const testing = std.testing;
 
-test "AEGIS128L" {
+test "AEGIS128L test vector 1" {
     const key: [AEGIS128L.key_length]u8 = [_]u8{ 0x10, 0x01 } ++ [_]u8{0x00} ** 14;
     const nonce: [AEGIS128L.nonce_length]u8 = [_]u8{ 0x10, 0x00, 0x02 } ++ [_]u8{0x00} ** 13;
     const ad = [8]u8{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
@@ -195,3 +356,60 @@ test "AEGIS128L" {
     tag[0] +%= 1;
     testing.expectError(error.AuthenticationFailed, AEGIS128L.decrypt(&m2, &c, tag, &ad, nonce, key));
 }
+
+test "AEGIS128L test vector 2" {
+    const key: [AEGIS128L.key_length]u8 = [_]u8{0x00} ** 16;
+    const nonce: [AEGIS128L.nonce_length]u8 = [_]u8{0x00} ** 16;
+    const ad = [_]u8{};
+    const m = [_]u8{0x00} ** 16;
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [AEGIS128L.tag_length]u8 = undefined;
+
+    AEGIS128L.encrypt(&c, &tag, &m, &ad, nonce, key);
+    try AEGIS128L.decrypt(&m2, &c, tag, &ad, nonce, key);
+    testing.expectEqualSlices(u8, &m, &m2);
+
+    htest.assertEqual("41de9000a7b5e40e2d68bb64d99ebb19", &c);
+    htest.assertEqual("f4d997cc9b94227ada4fe4165422b1c8", &tag);
+}
+
+test "AEGIS256 test vector 1" {
+    const key: [AEGIS256.key_length]u8 = [_]u8{ 0x10, 0x01 } ++ [_]u8{0x00} ** 30;
+    const nonce: [AEGIS256.nonce_length]u8 = [_]u8{ 0x10, 0x00, 0x02 } ++ [_]u8{0x00} ** 29;
+    const ad = [8]u8{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
+    const m = [32]u8{ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f };
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [AEGIS256.tag_length]u8 = undefined;
+
+    AEGIS256.encrypt(&c, &tag, &m, &ad, nonce, key);
+    try AEGIS256.decrypt(&m2, &c, tag, &ad, nonce, key);
+    testing.expectEqualSlices(u8, &m, &m2);
+
+    htest.assertEqual("f373079ed84b2709faee373584585d60accd191db310ef5d8b11833df9dec711", &c);
+    htest.assertEqual("8d86f91ee606e9ff26a01b64ccbdd91d", &tag);
+
+    c[0] +%= 1;
+    testing.expectError(error.AuthenticationFailed, AEGIS256.decrypt(&m2, &c, tag, &ad, nonce, key));
+    c[0] -%= 1;
+    tag[0] +%= 1;
+    testing.expectError(error.AuthenticationFailed, AEGIS256.decrypt(&m2, &c, tag, &ad, nonce, key));
+}
+
+test "AEGIS256 test vector 2" {
+    const key: [AEGIS256.key_length]u8 = [_]u8{0x00} ** 32;
+    const nonce: [AEGIS256.nonce_length]u8 = [_]u8{0x00} ** 32;
+    const ad = [_]u8{};
+    const m = [_]u8{0x00} ** 16;
+    var c: [m.len]u8 = undefined;
+    var m2: [m.len]u8 = undefined;
+    var tag: [AEGIS256.tag_length]u8 = undefined;
+
+    AEGIS256.encrypt(&c, &tag, &m, &ad, nonce, key);
+    try AEGIS256.decrypt(&m2, &c, tag, &ad, nonce, key);
+    testing.expectEqualSlices(u8, &m, &m2);
+
+    htest.assertEqual("b98f03a947807713d75a4fff9fc277a6", &c);
+    htest.assertEqual("478f3b50dc478ef7d5cf2d0f7cc13180", &tag);
+}
lib/std/crypto/benchmark.zig
@@ -149,7 +149,8 @@ const aeads = [_]Crypto{
     Crypto{ .ty = crypto.aead.ChaCha20Poly1305, .name = "chacha20Poly1305" },
     Crypto{ .ty = crypto.aead.XChaCha20Poly1305, .name = "xchacha20Poly1305" },
     Crypto{ .ty = crypto.aead.Gimli, .name = "gimli-aead" },
-    Crypto{ .ty = crypto.aead.AEGIS128L, .name = "aegis128l" },
+    Crypto{ .ty = crypto.aead.AEGIS128L, .name = "aegis-128l" },
+    Crypto{ .ty = crypto.aead.AEGIS256, .name = "aegis-256" },
 };
 
 pub fn benchmarkAead(comptime Aead: anytype, comptime bytes: comptime_int) !u64 {
lib/std/crypto.zig
@@ -29,6 +29,7 @@ pub const aead = struct {
     pub const ChaCha20Poly1305 = chacha20.Chacha20Poly1305;
     pub const XChaCha20Poly1305 = chacha20.XChacha20Poly1305;
     pub const AEGIS128L = @import("crypto/aegis.zig").AEGIS128L;
+    pub const AEGIS256 = @import("crypto/aegis.zig").AEGIS256;
 };
 
 /// MAC functions requiring single-use secret keys.