| ... | @@ -115,6 +115,14 @@ pub fn decryptBlock(xk: []const u32, dst: []u8, src: []const u8) void { | ... | @@ -115,6 +115,14 @@ pub fn decryptBlock(xk: []const u32, dst: []u8, src: []const u8) void { |
| 115 | mem.writeIntSliceBig(u32, dst[12..16], s3); | 115 | mem.writeIntSliceBig(u32, dst[12..16], s3); |
| 116 | } | 116 | } |
| 117 | | 117 | |
| | 118 | fn xorBytes(dst: []u8, a: []const u8, b: []const u8) usize { |
| | 119 | var n = std.math.min(dst.len, std.math.min(a.len, b.len)); |
| | 120 | for (dst[0..n]) |_, i| { |
| | 121 | dst[i] = a[i] ^ b[i]; |
| | 122 | } |
| | 123 | return n; |
| | 124 | } |
| | 125 | |
| 118 | pub const AES128 = AES(128); | 126 | pub const AES128 = AES(128); |
| 119 | pub const AES256 = AES(256); | 127 | pub const AES256 = AES(256); |
| 120 | | 128 | |
| ... | @@ -138,9 +146,48 @@ fn AES(comptime keysize: usize) type { | ... | @@ -138,9 +146,48 @@ fn AES(comptime keysize: usize) type { |
| 138 | pub fn decrypt(ctx: Self, dst: []u8, src: []const u8) void { | 146 | pub fn decrypt(ctx: Self, dst: []u8, src: []const u8) void { |
| 139 | decryptBlock(ctx.dec[0..], dst, src); | 147 | decryptBlock(ctx.dec[0..], dst, src); |
| 140 | } | 148 | } |
| | 149 | pub fn ctr(ctx: Self, dst: []u8, src: []const u8, iv: [16]u8) void { |
| | 150 | std.debug.assert(dst.len >= src.len); |
| | 151 | |
| | 152 | var keystream: [16]u8 = undefined; |
| | 153 | var ctrbuf = iv; |
| | 154 | var n: usize = 0; |
| | 155 | while (n < src.len) { |
| | 156 | ctx.encrypt(keystream[0..], ctrbuf[0..]); |
| | 157 | var ctr_i = std.mem.readIntSliceBig(u128, ctrbuf[0..]); |
| | 158 | std.mem.writeIntSliceBig(u128, ctrbuf[0..], ctr_i +% 1); |
| | 159 | |
| | 160 | n += xorBytes(dst[n..], src[n..], keystream); |
| | 161 | } |
| | 162 | } |
| 141 | }; | 163 | }; |
| 142 | } | 164 | } |
| 143 | | 165 | |
| | 166 | test "ctr" { |
| | 167 | // NIST SP 800-38A pp 55-58 |
| | 168 | { |
| | 169 | const key = [_]u8{ 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c }; |
| | 170 | const iv = [_]u8{ 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff }; |
| | 171 | const in = [_]u8{ |
| | 172 | 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a, |
| | 173 | 0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51, |
| | 174 | 0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef, |
| | 175 | 0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10, |
| | 176 | }; |
| | 177 | const exp_out = [_]u8{ |
| | 178 | 0x87, 0x4d, 0x61, 0x91, 0xb6, 0x20, 0xe3, 0x26, 0x1b, 0xef, 0x68, 0x64, 0x99, 0x0d, 0xb6, 0xce, |
| | 179 | 0x98, 0x06, 0xf6, 0x6b, 0x79, 0x70, 0xfd, 0xff, 0x86, 0x17, 0x18, 0x7b, 0xb9, 0xff, 0xfd, 0xff, |
| | 180 | 0x5a, 0xe4, 0xdf, 0x3e, 0xdb, 0xd5, 0xd3, 0x5e, 0x5b, 0x4f, 0x09, 0x02, 0x0d, 0xb0, 0x3e, 0xab, |
| | 181 | 0x1e, 0x03, 0x1d, 0xda, 0x2f, 0xbe, 0x03, 0xd1, 0x79, 0x21, 0x70, 0xa0, 0xf3, 0x00, 0x9c, 0xee, |
| | 182 | }; |
| | 183 | |
| | 184 | var out: [exp_out.len]u8 = undefined; |
| | 185 | var aes = AES128.init(key); |
| | 186 | aes.ctr(out[0..], in[0..], iv); |
| | 187 | testing.expectEqualSlices(u8, exp_out[0..], out[0..]); |
| | 188 | } |
| | 189 | } |
| | 190 | |
| 144 | test "encrypt" { | 191 | test "encrypt" { |
| 145 | // Appendix B | 192 | // Appendix B |
| 146 | { | 193 | { |
lukechampine <luke.champine@gmail.com> 2019-11-04 17:07:14-05:00
Andrew Kelley <andrew@ziglang.org> 2019-11-05 11:33:11-05:00
lib