fill

Fills the buffer with random bytes.

Function parameters

Parameters

self:*Self
buf_:[]u8

The seed must be uniform, secret and `secret_seed_length` bytes long.

Functions

init: The seed must be uniform, secret and `secret_seed_length` bytes long.
addEntropy: Inserts entropy to refresh the internal state.
random: Returns a `std.Random` structure backed by the current RNG.
fill: Fills the buffer with random bytes.

= Cipher.key_length

Values

secret_seed_length: = Cipher.key_length

Source

Implementation

pub fn fill(self: *Self, buf_: []u8) void {
    const bytes = self.state[Cipher.key_length..];
    var buf = buf_;

    const avail = bytes.len - self.offset;
    if (avail > 0) {
        // Bytes from the current block
        const n = @min(avail, buf.len);
        @memcpy(buf[0..n], bytes[self.offset..][0..n]);
        @memset(bytes[self.offset..][0..n], 0);
        buf = buf[n..];
        self.offset += n;
    }
    if (buf.len == 0) return;

    self.refill();

    // Full blocks
    while (buf.len >= bytes.len) {
        @memcpy(buf[0..bytes.len], bytes);
        buf = buf[bytes.len..];
        self.refill();
    }

    // Remaining bytes
    if (buf.len > 0) {
        @memcpy(buf, bytes[0..buf.len]);
        @memset(bytes[0..buf.len], 0);
        self.offset = buf.len;
    }
}