// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright 2021 Google LLC
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*
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* This program provides commands that dump certain types of output from the
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* fips140 kernel module, as required by the FIPS lab for evaluation purposes.
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*
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* While the fips140 kernel module can only be accessed directly by other kernel
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* code, an easy-to-use userspace utility program was desired for lab testing.
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* When possible, this program uses AF_ALG to access the crypto algorithms; this
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* requires that the kernel has AF_ALG enabled. Where AF_ALG isn't sufficient,
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* a custom device node /dev/fips140 is used instead; this requires that the
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* fips140 module is loaded and has evaluation testing support compiled in.
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*
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* This program can be compiled and run on an Android device as follows:
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*
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* NDK_DIR=$HOME/android-ndk-r23b # adjust directory path as needed
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* $NDK_DIR/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android31-clang \
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* fips140_lab_util.c -O2 -Wall -o fips140_lab_util
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* adb push fips140_lab_util /data/local/tmp/
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* adb root
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* adb shell /data/local/tmp/fips140_lab_util
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*/
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#include <errno.h>
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#include <fcntl.h>
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#include <getopt.h>
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#include <limits.h>
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#include <linux/if_alg.h>
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#include <stdarg.h>
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#include <stdbool.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/ioctl.h>
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#include <sys/socket.h>
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#include <sys/stat.h>
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#include <sys/sysmacros.h>
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#include <unistd.h>
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#include "../../crypto/fips140-eval-testing-uapi.h"
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/* ---------------------------------------------------------------------------
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* Utility functions
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* ---------------------------------------------------------------------------*/
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#define ARRAY_SIZE(A) (sizeof(A) / sizeof((A)[0]))
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#define MIN(a, b) ((a) < (b) ? (a) : (b))
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#define MAX(a, b) ((a) > (b) ? (a) : (b))
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static void __attribute__((noreturn))
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do_die(const char *format, va_list va, int err)
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{
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fputs("ERROR: ", stderr);
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vfprintf(stderr, format, va);
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if (err)
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fprintf(stderr, ": %s", strerror(err));
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putc('\n', stderr);
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exit(1);
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}
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static void __attribute__((noreturn, format(printf, 1, 2)))
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die_errno(const char *format, ...)
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{
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va_list va;
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va_start(va, format);
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do_die(format, va, errno);
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va_end(va);
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}
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static void __attribute__((noreturn, format(printf, 1, 2)))
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die(const char *format, ...)
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{
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va_list va;
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va_start(va, format);
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do_die(format, va, 0);
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va_end(va);
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}
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static void __attribute__((noreturn))
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assertion_failed(const char *expr, const char *file, int line)
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{
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die("Assertion failed: %s at %s:%d", expr, file, line);
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}
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#define ASSERT(e) ({ if (!(e)) assertion_failed(#e, __FILE__, __LINE__); })
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static void rand_bytes(uint8_t *bytes, size_t count)
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{
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size_t i;
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for (i = 0; i < count; i++)
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bytes[i] = rand();
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}
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static const char *booltostr(bool b)
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{
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return b ? "true" : "false";
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}
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static const char *bytes_to_hex(const uint8_t *bytes, size_t count)
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{
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static char hex[1025];
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size_t i;
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ASSERT(count <= 512);
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for (i = 0; i < count; i++)
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sprintf(&hex[2*i], "%02x", bytes[i]);
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return hex;
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}
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static void full_write(int fd, const void *buf, size_t count)
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{
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while (count) {
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ssize_t ret = write(fd, buf, count);
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if (ret < 0)
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die_errno("write failed");
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buf += ret;
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count -= ret;
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}
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}
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enum {
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OPT_AMOUNT,
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OPT_ITERATIONS,
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};
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static void usage(void);
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/* ---------------------------------------------------------------------------
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* /dev/fips140 ioctls
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* ---------------------------------------------------------------------------*/
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static int get_fips140_device_number(void)
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{
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FILE *f;
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char line[128];
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int number;
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char name[32];
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f = fopen("/proc/devices", "r");
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if (!f)
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die_errno("Failed to open /proc/devices");
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while (fgets(line, sizeof(line), f)) {
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if (sscanf(line, "%d %31s", &number, name) == 2 &&
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strcmp(name, "fips140") == 0)
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return number;
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}
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fclose(f);
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die("fips140 device node is unavailable.\n"
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"The fips140 device node is only available when the fips140 module is loaded\n"
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"and has been built with evaluation testing support.");
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}
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static void create_fips140_node_if_needed(void)
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{
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struct stat stbuf;
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int major;
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if (stat("/dev/fips140", &stbuf) == 0)
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return;
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major = get_fips140_device_number();
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if (mknod("/dev/fips140", S_IFCHR | 0600, makedev(major, 1)) != 0)
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die_errno("Failed to create fips140 device node");
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}
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static int fips140_dev_fd = -1;
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static int fips140_ioctl(int cmd, const void *arg)
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{
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if (fips140_dev_fd < 0) {
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create_fips140_node_if_needed();
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fips140_dev_fd = open("/dev/fips140", O_RDONLY);
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if (fips140_dev_fd < 0)
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die_errno("Failed to open /dev/fips140");
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}
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return ioctl(fips140_dev_fd, cmd, arg);
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}
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static bool fips140_is_approved_service(const char *name)
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{
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int ret = fips140_ioctl(FIPS140_IOCTL_IS_APPROVED_SERVICE, name);
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if (ret < 0)
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die_errno("FIPS140_IOCTL_IS_APPROVED_SERVICE unexpectedly failed");
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if (ret == 1)
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return true;
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if (ret == 0)
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return false;
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die("FIPS140_IOCTL_IS_APPROVED_SERVICE returned unexpected value %d",
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ret);
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}
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static const char *fips140_module_version(void)
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{
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static char buf[256];
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int ret;
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memset(buf, 0, sizeof(buf));
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ret = fips140_ioctl(FIPS140_IOCTL_MODULE_VERSION, buf);
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if (ret < 0)
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die_errno("FIPS140_IOCTL_MODULE_VERSION unexpectedly failed");
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if (ret != 0)
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die("FIPS140_IOCTL_MODULE_VERSION returned unexpected value %d",
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ret);
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return buf;
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}
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/* ---------------------------------------------------------------------------
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* AF_ALG utilities
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* ---------------------------------------------------------------------------*/
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#define AF_ALG_MAX_RNG_REQUEST_SIZE 128
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static int get_alg_fd(const char *alg_type, const char *alg_name)
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{
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struct sockaddr_alg addr = {};
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int alg_fd;
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alg_fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
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if (alg_fd < 0)
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die("Failed to create AF_ALG socket.\n"
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"AF_ALG is only available when it has been enabled in the kernel.\n");
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strncpy((char *)addr.salg_type, alg_type, sizeof(addr.salg_type) - 1);
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strncpy((char *)addr.salg_name, alg_name, sizeof(addr.salg_name) - 1);
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if (bind(alg_fd, (void *)&addr, sizeof(addr)) != 0)
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die_errno("Failed to bind AF_ALG socket to %s %s",
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alg_type, alg_name);
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return alg_fd;
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}
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static int get_req_fd(int alg_fd, const char *alg_name)
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{
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int req_fd = accept(alg_fd, NULL, NULL);
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if (req_fd < 0)
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die_errno("Failed to get request file descriptor for %s",
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alg_name);
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return req_fd;
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}
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/* ---------------------------------------------------------------------------
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* dump_jitterentropy command
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* ---------------------------------------------------------------------------*/
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static void dump_from_jent_fd(int fd, size_t count)
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{
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uint8_t buf[AF_ALG_MAX_RNG_REQUEST_SIZE];
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while (count) {
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ssize_t ret;
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memset(buf, 0, sizeof(buf));
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ret = read(fd, buf, MIN(count, sizeof(buf)));
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if (ret < 0)
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die_errno("error reading from jitterentropy_rng");
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full_write(STDOUT_FILENO, buf, ret);
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count -= ret;
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}
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}
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static int cmd_dump_jitterentropy(int argc, char *argv[])
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{
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static const struct option longopts[] = {
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{ "amount", required_argument, NULL, OPT_AMOUNT },
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{ "iterations", required_argument, NULL, OPT_ITERATIONS },
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{ NULL, 0, NULL, 0 },
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};
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size_t amount = 128;
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size_t iterations = 1;
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size_t i;
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int c;
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while ((c = getopt_long(argc, argv, "", longopts, NULL)) != -1) {
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switch (c) {
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case OPT_AMOUNT:
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amount = strtoul(optarg, NULL, 0);
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if (amount <= 0 || amount >= ULONG_MAX)
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die("invalid argument to --amount");
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break;
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case OPT_ITERATIONS:
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iterations = strtoul(optarg, NULL, 0);
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if (iterations <= 0 || iterations >= ULONG_MAX)
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die("invalid argument to --iterations");
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break;
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default:
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usage();
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return 1;
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}
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}
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for (i = 0; i < iterations; i++) {
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int alg_fd = get_alg_fd("rng", "jitterentropy_rng");
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int req_fd = get_req_fd(alg_fd, "jitterentropy_rng");
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dump_from_jent_fd(req_fd, amount);
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close(req_fd);
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close(alg_fd);
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}
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return 0;
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}
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/* ---------------------------------------------------------------------------
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* show_invalid_inputs command
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* ---------------------------------------------------------------------------*/
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enum direction {
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UNSPECIFIED,
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DECRYPT,
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ENCRYPT,
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};
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static const struct invalid_input_test {
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const char *alg_type;
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const char *alg_name;
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const char *key;
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size_t key_size;
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const char *msg;
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size_t msg_size;
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const char *iv;
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size_t iv_size;
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enum direction direction;
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int setkey_error;
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int crypt_error;
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} invalid_input_tests[] = {
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{
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.alg_type = "skcipher",
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.alg_name = "cbc(aes)",
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.key_size = 16,
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}, {
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.alg_type = "skcipher",
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.alg_name = "cbc(aes)",
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.key_size = 17,
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.setkey_error = EINVAL,
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}, {
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.alg_type = "skcipher",
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.alg_name = "cbc(aes)",
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.key_size = 24,
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}, {
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.alg_type = "skcipher",
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.alg_name = "cbc(aes)",
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.key_size = 32,
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}, {
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.alg_type = "skcipher",
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.alg_name = "cbc(aes)",
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.key_size = 33,
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.setkey_error = EINVAL,
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}, {
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.alg_type = "skcipher",
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.alg_name = "cbc(aes)",
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.key_size = 16,
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.msg_size = 1,
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.direction = DECRYPT,
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.crypt_error = EINVAL,
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}, {
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.alg_type = "skcipher",
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.alg_name = "cbc(aes)",
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.key_size = 16,
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.msg_size = 16,
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.direction = ENCRYPT,
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}, {
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.alg_type = "skcipher",
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.alg_name = "cbc(aes)",
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.key_size = 16,
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.msg_size = 17,
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.direction = ENCRYPT,
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.crypt_error = EINVAL,
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}, {
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.alg_type = "hash",
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.alg_name = "cmac(aes)",
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.key_size = 29,
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.setkey_error = EINVAL,
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}, {
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.alg_type = "skcipher",
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.alg_name = "xts(aes)",
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.key_size = 32,
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}, {
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.alg_type = "skcipher",
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.alg_name = "xts(aes)",
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.key = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
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"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0",
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.key_size = 32,
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.setkey_error = EINVAL,
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}
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};
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static const char *describe_crypt_op(const struct invalid_input_test *t)
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{
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if (t->direction == ENCRYPT)
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return "encryption";
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if (t->direction == DECRYPT)
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return "decryption";
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if (strcmp(t->alg_type, "hash") == 0)
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return "hashing";
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ASSERT(0);
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}
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static bool af_alg_setkey(const struct invalid_input_test *t, int alg_fd)
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{
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const uint8_t *key = (const uint8_t *)t->key;
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uint8_t _key[t->key_size];
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if (t->key_size == 0)
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return true;
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if (t->key == NULL) {
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rand_bytes(_key, t->key_size);
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key = _key;
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}
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if (setsockopt(alg_fd, SOL_ALG, ALG_SET_KEY, key, t->key_size) != 0) {
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printf("%s: setting %zu-byte key failed with error '%s'\n",
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t->alg_name, t->key_size, strerror(errno));
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printf("\tkey was %s\n\n", bytes_to_hex(key, t->key_size));
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ASSERT(t->setkey_error == errno);
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return false;
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}
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printf("%s: setting %zu-byte key succeeded\n",
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t->alg_name, t->key_size);
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printf("\tkey was %s\n\n", bytes_to_hex(key, t->key_size));
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ASSERT(t->setkey_error == 0);
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return true;
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}
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static void af_alg_process_msg(const struct invalid_input_test *t, int alg_fd)
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{
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struct iovec iov;
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struct msghdr hdr = {
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.msg_iov = &iov,
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.msg_iovlen = 1,
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};
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const uint8_t *msg = (const uint8_t *)t->msg;
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uint8_t *_msg = NULL;
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uint8_t *output = NULL;
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uint8_t *control = NULL;
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size_t controllen = 0;
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struct cmsghdr *cmsg;
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int req_fd;
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if (t->msg_size == 0)
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return;
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req_fd = get_req_fd(alg_fd, t->alg_name);
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if (t->msg == NULL) {
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_msg = malloc(t->msg_size);
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rand_bytes(_msg, t->msg_size);
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msg = _msg;
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}
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output = malloc(t->msg_size);
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iov.iov_base = (void *)msg;
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iov.iov_len = t->msg_size;
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if (t->direction != UNSPECIFIED)
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controllen += CMSG_SPACE(sizeof(uint32_t));
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if (t->iv_size)
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controllen += CMSG_SPACE(sizeof(struct af_alg_iv) + t->iv_size);
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control = calloc(1, controllen);
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hdr.msg_control = control;
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hdr.msg_controllen = controllen;
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cmsg = CMSG_FIRSTHDR(&hdr);
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if (t->direction != UNSPECIFIED) {
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cmsg->cmsg_level = SOL_ALG;
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cmsg->cmsg_type = ALG_SET_OP;
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cmsg->cmsg_len = CMSG_LEN(sizeof(uint32_t));
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*(uint32_t *)CMSG_DATA(cmsg) = t->direction == DECRYPT ?
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ALG_OP_DECRYPT : ALG_OP_ENCRYPT;
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cmsg = CMSG_NXTHDR(&hdr, cmsg);
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}
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if (t->iv_size) {
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struct af_alg_iv *alg_iv;
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cmsg->cmsg_level = SOL_ALG;
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cmsg->cmsg_type = ALG_SET_IV;
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cmsg->cmsg_len = CMSG_LEN(sizeof(*alg_iv) + t->iv_size);
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alg_iv = (struct af_alg_iv *)CMSG_DATA(cmsg);
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alg_iv->ivlen = t->iv_size;
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memcpy(alg_iv->iv, t->iv, t->iv_size);
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}
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if (sendmsg(req_fd, &hdr, 0) != t->msg_size)
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die_errno("sendmsg failed");
|
|
if (read(req_fd, output, t->msg_size) != t->msg_size) {
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printf("%s: %s of %zu-byte message failed with error '%s'\n",
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t->alg_name, describe_crypt_op(t), t->msg_size,
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strerror(errno));
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printf("\tmessage was %s\n\n", bytes_to_hex(msg, t->msg_size));
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ASSERT(t->crypt_error == errno);
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} else {
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printf("%s: %s of %zu-byte message succeeded\n",
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t->alg_name, describe_crypt_op(t), t->msg_size);
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printf("\tmessage was %s\n\n", bytes_to_hex(msg, t->msg_size));
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ASSERT(t->crypt_error == 0);
|
}
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free(_msg);
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free(output);
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free(control);
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close(req_fd);
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}
|
|
static void test_invalid_input(const struct invalid_input_test *t)
|
{
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int alg_fd = get_alg_fd(t->alg_type, t->alg_name);
|
|
if (af_alg_setkey(t, alg_fd))
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af_alg_process_msg(t, alg_fd);
|
|
close(alg_fd);
|
}
|
|
static int cmd_show_invalid_inputs(int argc, char *argv[])
|
{
|
int i;
|
|
for (i = 0; i < ARRAY_SIZE(invalid_input_tests); i++)
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test_invalid_input(&invalid_input_tests[i]);
|
return 0;
|
}
|
|
/* ---------------------------------------------------------------------------
|
* show_module_version command
|
* ---------------------------------------------------------------------------*/
|
|
static int cmd_show_module_version(int argc, char *argv[])
|
{
|
printf("fips140_module_version() => \"%s\"\n",
|
fips140_module_version());
|
return 0;
|
}
|
|
/* ---------------------------------------------------------------------------
|
* show_service_indicators command
|
* ---------------------------------------------------------------------------*/
|
|
static const char * const default_services_to_show[] = {
|
"aes",
|
"cbc(aes)",
|
"cbcmac(aes)",
|
"cmac(aes)",
|
"ctr(aes)",
|
"cts(cbc(aes))",
|
"ecb(aes)",
|
"essiv(cbc(aes),sha256)",
|
"gcm(aes)",
|
"hmac(sha1)",
|
"hmac(sha224)",
|
"hmac(sha256)",
|
"hmac(sha384)",
|
"hmac(sha512)",
|
"jitterentropy_rng",
|
"sha1",
|
"sha224",
|
"sha256",
|
"sha384",
|
"sha512",
|
"stdrng",
|
"xcbc(aes)",
|
"xts(aes)",
|
};
|
|
static int cmd_show_service_indicators(int argc, char *argv[])
|
{
|
const char * const *services = default_services_to_show;
|
int count = ARRAY_SIZE(default_services_to_show);
|
int i;
|
|
if (argc > 1) {
|
services = (const char **)(argv + 1);
|
count = argc - 1;
|
}
|
for (i = 0; i < count; i++) {
|
printf("fips140_is_approved_service(\"%s\") => %s\n",
|
services[i],
|
booltostr(fips140_is_approved_service(services[i])));
|
}
|
return 0;
|
}
|
|
/* ---------------------------------------------------------------------------
|
* main()
|
* ---------------------------------------------------------------------------*/
|
|
static const struct command {
|
const char *name;
|
int (*func)(int argc, char *argv[]);
|
} commands[] = {
|
{ "dump_jitterentropy", cmd_dump_jitterentropy },
|
{ "show_invalid_inputs", cmd_show_invalid_inputs },
|
{ "show_module_version", cmd_show_module_version },
|
{ "show_service_indicators", cmd_show_service_indicators },
|
};
|
|
static void usage(void)
|
{
|
fprintf(stderr,
|
"Usage:\n"
|
" fips140_lab_util dump_jitterentropy [OPTION]...\n"
|
" fips140_lab_util show_invalid_inputs\n"
|
" fips140_lab_util show_module_version\n"
|
" fips140_lab_util show_service_indicators [SERVICE]...\n"
|
"\n"
|
"Options for dump_jitterentropy:\n"
|
" --amount=AMOUNT Amount to dump in bytes per iteration (default 128)\n"
|
" --iterations=COUNT Number of start-up iterations (default 1)\n"
|
);
|
}
|
|
int main(int argc, char *argv[])
|
{
|
int i;
|
|
if (argc < 2) {
|
usage();
|
return 2;
|
}
|
for (i = 1; i < argc; i++) {
|
if (strcmp(argv[i], "--help") == 0) {
|
usage();
|
return 2;
|
}
|
}
|
|
for (i = 0; i < ARRAY_SIZE(commands); i++) {
|
if (strcmp(commands[i].name, argv[1]) == 0)
|
return commands[i].func(argc - 1, argv + 1);
|
}
|
fprintf(stderr, "Unknown command: %s\n\n", argv[1]);
|
usage();
|
return 2;
|
}
|
