1 /* 2 * QEMU guest-visible random functions 3 * 4 * Copyright 2019 Linaro, Ltd. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the Free 8 * Software Foundation; either version 2 of the License, or (at your option) 9 * any later version. 10 */ 11 12 #ifndef QEMU_GUEST_RANDOM_H 13 #define QEMU_GUEST_RANDOM_H 14 15 /** 16 * qemu_guest_random_seed_main(const char *seedstr, Error **errp) 17 * @seedstr: a non-NULL pointer to a C string 18 * @errp: an error indicator 19 * 20 * The @seedstr value is that which accompanies the -seed argument. 21 * This forces qemu_guest_getrandom into deterministic mode. 22 * 23 * Returns 0 on success, < 0 on failure while setting *errp. 24 */ 25 int qemu_guest_random_seed_main(const char *seedstr, Error **errp); 26 27 /** 28 * qemu_guest_random_seed_thread_part1(void) 29 * 30 * If qemu_getrandom is in deterministic mode, returns an 31 * independent seed for the new thread. Otherwise returns 0. 32 */ 33 uint64_t qemu_guest_random_seed_thread_part1(void); 34 35 /** 36 * qemu_guest_random_seed_thread_part2(uint64_t seed) 37 * @seed: a value for the new thread. 38 * 39 * If qemu_guest_getrandom is in deterministic mode, this stores an 40 * independent seed for the new thread. Otherwise a no-op. 41 */ 42 void qemu_guest_random_seed_thread_part2(uint64_t seed); 43 44 /** 45 * qemu_guest_getrandom(void *buf, size_t len, Error **errp) 46 * @buf: a buffer of bytes to be written 47 * @len: the number of bytes in @buf 48 * @errp: an error indicator 49 * 50 * Fills len bytes in buf with random data. This should only be used 51 * for data presented to the guest. Host-side crypto services should 52 * use qcrypto_random_bytes. 53 * 54 * Returns 0 on success, < 0 on failure while setting *errp. 55 */ 56 int qemu_guest_getrandom(void *buf, size_t len, Error **errp); 57 58 /** 59 * qemu_guest_getrandom_nofail(void *buf, size_t len) 60 * @buf: a buffer of bytes to be written 61 * @len: the number of bytes in @buf 62 * 63 * Like qemu_guest_getrandom, but will assert for failure. 64 * Use this when there is no reasonable recovery. 65 */ 66 void qemu_guest_getrandom_nofail(void *buf, size_t len); 67 68 #endif /* QEMU_GUEST_RANDOM_H */ 69