X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fed25519%2Fge.h;fp=src%2Fed25519%2Fge.h;h=17fde2df1ff38a4a8558169163b27f2935474519;hp=0000000000000000000000000000000000000000;hb=2f01744f82be542894fe2ceecbfb9ead93c9ffa5;hpb=d6734a2da483675f5bcc9cf7b15723a409b1019f diff --git a/src/ed25519/ge.h b/src/ed25519/ge.h new file mode 100644 index 00000000..17fde2df --- /dev/null +++ b/src/ed25519/ge.h @@ -0,0 +1,74 @@ +#ifndef GE_H +#define GE_H + +#include "fe.h" + + +/* +ge means group element. + +Here the group is the set of pairs (x,y) of field elements (see fe.h) +satisfying -x^2 + y^2 = 1 + d x^2y^2 +where d = -121665/121666. + +Representations: + ge_p2 (projective): (X:Y:Z) satisfying x=X/Z, y=Y/Z + ge_p3 (extended): (X:Y:Z:T) satisfying x=X/Z, y=Y/Z, XY=ZT + ge_p1p1 (completed): ((X:Z),(Y:T)) satisfying x=X/Z, y=Y/T + ge_precomp (Duif): (y+x,y-x,2dxy) +*/ + +typedef struct { + fe X; + fe Y; + fe Z; +} ge_p2; + +typedef struct { + fe X; + fe Y; + fe Z; + fe T; +} ge_p3; + +typedef struct { + fe X; + fe Y; + fe Z; + fe T; +} ge_p1p1; + +typedef struct { + fe yplusx; + fe yminusx; + fe xy2d; +} ge_precomp; + +typedef struct { + fe YplusX; + fe YminusX; + fe Z; + fe T2d; +} ge_cached; + +void ge_p3_tobytes(unsigned char *s, const ge_p3 *h); +void ge_tobytes(unsigned char *s, const ge_p2 *h); +int ge_frombytes_negate_vartime(ge_p3 *h, const unsigned char *s); + +void ge_add(ge_p1p1 *r, const ge_p3 *p, const ge_cached *q); +void ge_sub(ge_p1p1 *r, const ge_p3 *p, const ge_cached *q); +void ge_double_scalarmult_vartime(ge_p2 *r, const unsigned char *a, const ge_p3 *A, const unsigned char *b); +void ge_madd(ge_p1p1 *r, const ge_p3 *p, const ge_precomp *q); +void ge_msub(ge_p1p1 *r, const ge_p3 *p, const ge_precomp *q); +void ge_scalarmult_base(ge_p3 *h, const unsigned char *a); + +void ge_p1p1_to_p2(ge_p2 *r, const ge_p1p1 *p); +void ge_p1p1_to_p3(ge_p3 *r, const ge_p1p1 *p); +void ge_p2_0(ge_p2 *h); +void ge_p2_dbl(ge_p1p1 *r, const ge_p2 *p); +void ge_p3_0(ge_p3 *h); +void ge_p3_dbl(ge_p1p1 *r, const ge_p3 *p); +void ge_p3_to_cached(ge_cached *r, const ge_p3 *p); +void ge_p3_to_p2(ge_p2 *r, const ge_p3 *p); + +#endif