rand.go

// Copyright 2024 Thales Group
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
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// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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package crypto11

import (
	"io"
)

// NewRandomReader returns a reader for the random number generator on the token.
func (c *Context) NewRandomReader() (io.Reader, error) {
	if c.closed.Get() {
		return nil, errClosed
	}

	return pkcs11RandReader{c}, nil
}

// pkcs11RandReader is a random number reader that uses PKCS#11.
type pkcs11RandReader struct {
	context *Context
}

// This implements the Reader interface for pkcs11RandReader.
func (r pkcs11RandReader) Read(data []byte) (n int, err error) {
	var result []byte

	if err = r.context.withSession(func(session *pkcs11Session) error {
		result, err = r.context.ctx.GenerateRandom(session.handle, len(data))
		return err
	}); err != nil {
		return 0, err
	}
	copy(data, result)
	return len(result), err
}