ref: 1018d7a7091fd5e0433f501a3474cdc3fec322cc
dir: /libmp/port/mptole.c/
#include "os.h" #include <mp.h> #include "dat.h" // convert an mpint into a little endian byte array (least significant byte first) // return number of bytes converted // if p == nil, allocate and result array int mptole(mpint *b, uchar *p, uint n, uchar **pp) { int i, j; mpdigit x; uchar *e, *s; if(p == nil){ n = (b->top+1)*Dbytes; p = malloc(n); } if(pp != nil) *pp = p; if(p == nil) return -1; memset(p, 0, n); // special case 0 if(b->top == 0){ if(n < 1) return -1; else return 0; } s = p; e = s+n; for(i = 0; i < b->top-1; i++){ x = b->p[i]; for(j = 0; j < Dbytes; j++){ if(p >= e) return -1; *p++ = x; x >>= 8; } } x = b->p[i]; while(x > 0){ if(p >= e) return -1; *p++ = x; x >>= 8; } return p - s; }