1 /* $OpenBSD: chacha.c,v 1.2 2023/07/17 05:26:38 djm Exp $ */
17 #define U8C(v) (v##U)  argument
18 #define U32C(v) (v##U)  argument
20 #define U8V(v) ((u8)(v) & U8C(0xFF))  argument
21 #define U32V(v) ((u32)(v) & U32C(0xFFFFFFFF))  argument
23 #define ROTL32(v, n) \  argument
24   (U32V((v) << (n)) | ((v) >> (32 - (n))))
29    ((u32)((p)[2]) << 16) | \
32 #define U32TO8_LITTLE(p, v) \  argument
34     (p)[0] = U8V((v)      ); \
35     (p)[1] = U8V((v) >>  8); \
36     (p)[2] = U8V((v) >> 16); \
37     (p)[3] = U8V((v) >> 24); \
40 #define ROTATE(v,c) (ROTL32(v,c))  argument
41 #define XOR(v,w) ((v) ^ (w))  argument
42 #define PLUS(v,w) (U32V((v) + (w)))  argument
43 #define PLUSONE(v) (PLUS((v),1))  argument
46   a = PLUS(a,b); d = ROTATE(XOR(d,a),16); \
51 static const char sigma[16] = "expand 32-byte k";
52 static const char tau[16] = "expand 16-byte k";
64     k += 16;  in chacha_keysetup()
170     x4 = XOR(x4,U8TO32_LITTLE(m + 16));  in chacha_encrypt_bytes()
193     U32TO8_LITTLE(c + 16,x4);  in chacha_encrypt_bytes()