diff options
| -rw-r--r-- | sys/src/9/port/random.c | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/sys/src/9/port/random.c b/sys/src/9/port/random.c index 012424aa6..d401e7e01 100644 --- a/sys/src/9/port/random.c +++ b/sys/src/9/port/random.c @@ -86,22 +86,37 @@ randominit(void) } ulong -randomread(void *xp, ulong n) +randomread(void *p, ulong n) { + Chachastate c; + ulong b; + if(n == 0) return 0; if(hwrandbuf != nil) - (*hwrandbuf)(xp, n); + (*hwrandbuf)(p, n); - if(waserror()){ - qunlock(rs); - nexterror(); - } + /* copy chacha state and advance block counter */ qlock(rs); - chacha_encrypt((uchar*)xp, n, rs); + c = *rs; + b = rs->input[12]; + rs->input[12] += (n + ChachaBsize-1)/ChachaBsize; + if(rs->input[12] < b) rs->input[13]++; qunlock(rs); - poperror(); + + /* encrypt the buffer, can fault */ + chacha_encrypt((uchar*)p, n, &c); + + /* prevent state leakage */ + memset(&c, 0, sizeof(c)); return n; } + +/* used by fastrand() */ +void +genrandom(uchar *p, int n) +{ + randomread(p, n); +} |