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@@ -26,298 +26,292 @@ THE SOFTWARE. |
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// *before* randombytes.h is included. Otherwise SYS_getrandom will not be |
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// declared. |
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#if defined(__linux__) |
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# define _GNU_SOURCE |
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#define _GNU_SOURCE |
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#endif /* defined(__linux__) */ |
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#include "randombytes.h" |
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#if defined(_WIN32) |
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/* Windows */ |
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# include <windows.h> |
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# include <wincrypt.h> /* CryptAcquireContext, CryptGenRandom */ |
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#include <wincrypt.h> /* CryptAcquireContext, CryptGenRandom */ |
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#include <windows.h> |
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#endif /* defined(_WIN32) */ |
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#if defined(__linux__) |
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/* Linux */ |
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// We would need to include <linux/random.h>, but not every target has access |
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// to the linux headers. We only need RNDGETENTCNT, so we instead inline it. |
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// RNDGETENTCNT is originally defined in `include/uapi/linux/random.h` in the |
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// linux repo. |
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# define RNDGETENTCNT 0x80045200 |
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# include <assert.h> |
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# include <errno.h> |
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# include <fcntl.h> |
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# include <poll.h> |
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# include <stdint.h> |
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# include <stdio.h> |
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# include <sys/ioctl.h> |
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# include <sys/stat.h> |
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# include <sys/syscall.h> |
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# include <sys/types.h> |
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# include <unistd.h> |
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#define RNDGETENTCNT 0x80045200 |
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#include <assert.h> |
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#include <errno.h> |
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#include <fcntl.h> |
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#include <poll.h> |
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#include <stdint.h> |
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#include <stdio.h> |
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#include <sys/ioctl.h> |
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#include <sys/stat.h> |
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#include <sys/syscall.h> |
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#include <sys/types.h> |
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#include <unistd.h> |
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// We need SSIZE_MAX as the maximum read len from /dev/urandom |
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# if !defined(SSIZE_MAX) |
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# define SSIZE_MAX (SIZE_MAX / 2 - 1) |
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# endif /* defined(SSIZE_MAX) */ |
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#if !defined(SSIZE_MAX) |
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#define SSIZE_MAX (SIZE_MAX / 2 - 1) |
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#endif /* defined(SSIZE_MAX) */ |
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#endif /* defined(__linux__) */ |
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#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) |
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/* Dragonfly, FreeBSD, NetBSD, OpenBSD (has arc4random) */ |
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# include <sys/param.h> |
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# if defined(BSD) |
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# include <stdlib.h> |
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# endif |
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#include <sys/param.h> |
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#if defined(BSD) |
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#include <stdlib.h> |
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#endif |
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#endif |
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#if defined(__EMSCRIPTEN__) |
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# include <assert.h> |
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# include <emscripten.h> |
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# include <errno.h> |
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# include <stdbool.h> |
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#include <assert.h> |
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#include <emscripten.h> |
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#include <errno.h> |
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#include <stdbool.h> |
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#endif /* defined(__EMSCRIPTEN__) */ |
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#if defined(_WIN32) |
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static int randombytes_win32_randombytes(void* buf, const size_t n) |
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{ |
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HCRYPTPROV ctx; |
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BOOL tmp; |
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static int randombytes_win32_randombytes(void *buf, const size_t n) { |
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HCRYPTPROV ctx; |
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BOOL tmp; |
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tmp = CryptAcquireContext(&ctx, NULL, NULL, PROV_RSA_FULL, |
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CRYPT_VERIFYCONTEXT); |
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if (tmp == FALSE) return -1; |
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tmp = CryptAcquireContext(&ctx, NULL, NULL, PROV_RSA_FULL, |
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CRYPT_VERIFYCONTEXT); |
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if (tmp == FALSE) |
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return -1; |
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tmp = CryptGenRandom(ctx, n, (BYTE*) buf); |
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if (tmp == FALSE) return -1; |
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tmp = CryptGenRandom(ctx, n, (BYTE *)buf); |
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if (tmp == FALSE) |
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return -1; |
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tmp = CryptReleaseContext(ctx, 0); |
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if (tmp == FALSE) return -1; |
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tmp = CryptReleaseContext(ctx, 0); |
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if (tmp == FALSE) |
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return -1; |
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return 0; |
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return 0; |
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} |
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#endif /* defined(_WIN32) */ |
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#if defined(__linux__) && defined(SYS_getrandom) |
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static int randombytes_linux_randombytes_getrandom(void *buf, size_t n) |
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{ |
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/* I have thought about using a separate PRF, seeded by getrandom, but |
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* it turns out that the performance of getrandom is good enough |
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* (250 MB/s on my laptop). |
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*/ |
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size_t offset = 0, chunk; |
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int ret; |
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while (n > 0) { |
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/* getrandom does not allow chunks larger than 33554431 */ |
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chunk = n <= 33554431 ? n : 33554431; |
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do { |
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ret = syscall(SYS_getrandom, (char *)buf + offset, chunk, 0); |
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} while (ret == -1 && errno == EINTR); |
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if (ret < 0) { |
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return ret; |
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} |
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offset += ret; |
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n -= ret; |
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} |
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assert(n == 0); |
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return 0; |
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static int randombytes_linux_randombytes_getrandom(void *buf, size_t n) { |
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/* I have thought about using a separate PRF, seeded by getrandom, but |
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* it turns out that the performance of getrandom is good enough |
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* (250 MB/s on my laptop). |
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*/ |
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size_t offset = 0, chunk; |
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int ret; |
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while (n > 0) { |
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/* getrandom does not allow chunks larger than 33554431 */ |
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chunk = n <= 33554431 ? n : 33554431; |
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do { |
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ret = syscall(SYS_getrandom, (char *)buf + offset, chunk, 0); |
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} while (ret == -1 && errno == EINTR); |
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if (ret < 0) { |
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return ret; |
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} |
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offset += ret; |
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n -= ret; |
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} |
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assert(n == 0); |
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return 0; |
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} |
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#endif /* defined(__linux__) && defined(SYS_getrandom) */ |
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#if defined(__linux__) && !defined(SYS_getrandom) |
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static int randombytes_linux_read_entropy_ioctl(int device, int *entropy) |
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{ |
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return ioctl(device, RNDGETENTCNT, entropy); |
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static int randombytes_linux_read_entropy_ioctl(int device, int *entropy) { |
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return ioctl(device, RNDGETENTCNT, entropy); |
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} |
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static int randombytes_linux_read_entropy_proc(FILE *stream, int *entropy) |
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{ |
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int retcode; |
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do { |
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rewind(stream); |
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retcode = fscanf(stream, "%d", entropy); |
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} while (retcode != 1 && errno == EINTR); |
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if (retcode != 1) { |
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return -1; |
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} |
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return 0; |
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static int randombytes_linux_read_entropy_proc(FILE *stream, int *entropy) { |
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int retcode; |
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do { |
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rewind(stream); |
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retcode = fscanf(stream, "%d", entropy); |
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} while (retcode != 1 && errno == EINTR); |
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if (retcode != 1) { |
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return -1; |
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} |
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return 0; |
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} |
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static int randombytes_linux_wait_for_entropy(int device) |
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{ |
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/* We will block on /dev/random, because any increase in the OS' entropy |
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* level will unblock the request. I use poll here (as does libsodium), |
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* because we don't *actually* want to read from the device. */ |
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enum { IOCTL, PROC } strategy = IOCTL; |
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const int bits = 128; |
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struct pollfd pfd; |
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int fd; |
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FILE *proc_file; |
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int retcode, retcode_error = 0; // Used as return codes throughout this function |
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int entropy = 0; |
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/* If the device has enough entropy already, we will want to return early */ |
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retcode = randombytes_linux_read_entropy_ioctl(device, &entropy); |
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if (retcode != 0 && errno == ENOTTY) { |
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/* The ioctl call on /dev/urandom has failed due to a ENOTTY (i.e. |
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* unsupported action). We will fall back to reading from |
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* `/proc/sys/kernel/random/entropy_avail`. This is obviously less |
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* ideal, but at this point it seems we have no better option. */ |
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strategy = PROC; |
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// Open the entropy count file |
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proc_file = fopen("/proc/sys/kernel/random/entropy_avail", "r"); |
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} else if (retcode != 0) { |
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// Unrecoverable ioctl error |
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return -1; |
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} |
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if (entropy >= bits) { |
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return 0; |
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} |
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do { |
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fd = open("/dev/random", O_RDONLY); |
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} while (fd == -1 && errno == EINTR); /* EAGAIN will not occur */ |
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if (fd == -1) { |
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/* Unrecoverable IO error */ |
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return -1; |
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} |
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pfd.fd = fd; |
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pfd.events = POLLIN; |
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for (;;) { |
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retcode = poll(&pfd, 1, -1); |
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if (retcode == -1 && (errno == EINTR || errno == EAGAIN)) { |
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continue; |
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} else if (retcode == 1) { |
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if (strategy == IOCTL) { |
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retcode = randombytes_linux_read_entropy_ioctl(device, &entropy); |
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} else if (strategy == PROC) { |
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retcode = randombytes_linux_read_entropy_proc(proc_file, &entropy); |
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} else { |
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return -1; // Unreachable |
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} |
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if (retcode != 0) { |
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// Unrecoverable I/O error |
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retcode_error = retcode; |
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break; |
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} |
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if (entropy >= bits) { |
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break; |
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} |
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} else { |
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// Unreachable: poll() should only return -1 or 1 |
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retcode_error = -1; |
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break; |
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} |
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} |
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do { |
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retcode = close(fd); |
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} while (retcode == -1 && errno == EINTR); |
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if (strategy == PROC) { |
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do { |
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retcode = fclose(proc_file); |
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} while (retcode == -1 && errno == EINTR); |
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} |
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if (retcode_error != 0) { |
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return retcode_error; |
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} |
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return retcode; |
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static int randombytes_linux_wait_for_entropy(int device) { |
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/* We will block on /dev/random, because any increase in the OS' entropy |
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* level will unblock the request. I use poll here (as does libsodium), |
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* because we don't *actually* want to read from the device. */ |
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enum { IOCTL, PROC } strategy = IOCTL; |
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const int bits = 128; |
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struct pollfd pfd; |
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int fd; |
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FILE *proc_file; |
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int retcode, |
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retcode_error = 0; // Used as return codes throughout this function |
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int entropy = 0; |
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/* If the device has enough entropy already, we will want to return early */ |
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retcode = randombytes_linux_read_entropy_ioctl(device, &entropy); |
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if (retcode != 0 && errno == ENOTTY) { |
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/* The ioctl call on /dev/urandom has failed due to a ENOTTY (i.e. |
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* unsupported action). We will fall back to reading from |
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* `/proc/sys/kernel/random/entropy_avail`. This is obviously less |
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* ideal, but at this point it seems we have no better option. */ |
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strategy = PROC; |
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// Open the entropy count file |
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proc_file = fopen("/proc/sys/kernel/random/entropy_avail", "r"); |
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} else if (retcode != 0) { |
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// Unrecoverable ioctl error |
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return -1; |
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} |
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if (entropy >= bits) { |
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return 0; |
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} |
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do { |
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fd = open("/dev/random", O_RDONLY); |
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} while (fd == -1 && errno == EINTR); /* EAGAIN will not occur */ |
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if (fd == -1) { |
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/* Unrecoverable IO error */ |
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return -1; |
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} |
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pfd.fd = fd; |
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pfd.events = POLLIN; |
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for (;;) { |
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retcode = poll(&pfd, 1, -1); |
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if (retcode == -1 && (errno == EINTR || errno == EAGAIN)) { |
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continue; |
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} else if (retcode == 1) { |
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if (strategy == IOCTL) { |
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retcode = |
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randombytes_linux_read_entropy_ioctl(device, &entropy); |
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} else if (strategy == PROC) { |
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retcode = |
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randombytes_linux_read_entropy_proc(proc_file, &entropy); |
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} else { |
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return -1; // Unreachable |
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} |
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if (retcode != 0) { |
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// Unrecoverable I/O error |
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retcode_error = retcode; |
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break; |
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} |
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if (entropy >= bits) { |
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break; |
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} |
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} else { |
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// Unreachable: poll() should only return -1 or 1 |
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retcode_error = -1; |
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break; |
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} |
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} |
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do { |
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retcode = close(fd); |
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} while (retcode == -1 && errno == EINTR); |
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if (strategy == PROC) { |
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do { |
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retcode = fclose(proc_file); |
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} while (retcode == -1 && errno == EINTR); |
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} |
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if (retcode_error != 0) { |
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return retcode_error; |
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} |
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return retcode; |
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} |
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static int randombytes_linux_randombytes_urandom(void *buf, size_t n) |
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{ |
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int fd; |
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size_t offset = 0, count; |
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ssize_t tmp; |
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do { |
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fd = open("/dev/urandom", O_RDONLY); |
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} while (fd == -1 && errno == EINTR); |
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if (fd == -1) return -1; |
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if (randombytes_linux_wait_for_entropy(fd) == -1) return -1; |
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while (n > 0) { |
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count = n <= SSIZE_MAX ? n : SSIZE_MAX; |
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tmp = read(fd, (char *)buf + offset, count); |
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if (tmp == -1 && (errno == EAGAIN || errno == EINTR)) { |
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continue; |
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} |
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if (tmp == -1) return -1; /* Unrecoverable IO error */ |
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offset += tmp; |
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n -= tmp; |
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} |
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assert(n == 0); |
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return 0; |
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static int randombytes_linux_randombytes_urandom(void *buf, size_t n) { |
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int fd; |
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size_t offset = 0, count; |
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ssize_t tmp; |
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do { |
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fd = open("/dev/urandom", O_RDONLY); |
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} while (fd == -1 && errno == EINTR); |
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if (fd == -1) |
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return -1; |
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if (randombytes_linux_wait_for_entropy(fd) == -1) |
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return -1; |
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while (n > 0) { |
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count = n <= SSIZE_MAX ? n : SSIZE_MAX; |
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tmp = read(fd, (char *)buf + offset, count); |
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if (tmp == -1 && (errno == EAGAIN || errno == EINTR)) { |
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continue; |
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} |
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if (tmp == -1) |
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|
|
return -1; /* Unrecoverable IO error */ |
|
|
|
offset += tmp; |
|
|
|
n -= tmp; |
|
|
|
} |
|
|
|
assert(n == 0); |
|
|
|
return 0; |
|
|
|
} |
|
|
|
#endif /* defined(__linux__) && !defined(SYS_getrandom) */ |
|
|
|
|
|
|
|
|
|
|
|
#if defined(BSD) |
|
|
|
static int randombytes_bsd_randombytes(void *buf, size_t n) |
|
|
|
{ |
|
|
|
arc4random_buf(buf, n); |
|
|
|
return 0; |
|
|
|
static int randombytes_bsd_randombytes(void *buf, size_t n) { |
|
|
|
arc4random_buf(buf, n); |
|
|
|
return 0; |
|
|
|
} |
|
|
|
#endif /* defined(BSD) */ |
|
|
|
|
|
|
|
|
|
|
|
#if defined(__EMSCRIPTEN__) |
|
|
|
static int randombytes_js_randombytes_nodejs(void *buf, size_t n) { |
|
|
|
const int ret = EM_ASM_INT({ |
|
|
|
var crypto; |
|
|
|
try { |
|
|
|
crypto = require('crypto'); |
|
|
|
} catch (error) { |
|
|
|
return -2; |
|
|
|
} |
|
|
|
try { |
|
|
|
writeArrayToMemory(crypto.randomBytes($1), $0); |
|
|
|
return 0; |
|
|
|
} catch (error) { |
|
|
|
return -1; |
|
|
|
} |
|
|
|
}, buf, n); |
|
|
|
switch (ret) { |
|
|
|
case 0: |
|
|
|
return 0; |
|
|
|
case -1: |
|
|
|
errno = EINVAL; |
|
|
|
return -1; |
|
|
|
case -2: |
|
|
|
errno = ENOSYS; |
|
|
|
return -1; |
|
|
|
} |
|
|
|
assert(false); // Unreachable |
|
|
|
const int ret = EM_ASM_INT( |
|
|
|
{ |
|
|
|
var crypto; |
|
|
|
try { |
|
|
|
crypto = require('crypto'); |
|
|
|
} catch (error) { |
|
|
|
return -2; |
|
|
|
} |
|
|
|
try { |
|
|
|
writeArrayToMemory(crypto.randomBytes($1), $0); |
|
|
|
return 0; |
|
|
|
} catch (error) { |
|
|
|
return -1; |
|
|
|
} |
|
|
|
}, |
|
|
|
buf, n); |
|
|
|
switch (ret) { |
|
|
|
case 0: |
|
|
|
return 0; |
|
|
|
case -1: |
|
|
|
errno = EINVAL; |
|
|
|
return -1; |
|
|
|
case -2: |
|
|
|
errno = ENOSYS; |
|
|
|
return -1; |
|
|
|
} |
|
|
|
assert(false); // Unreachable |
|
|
|
} |
|
|
|
#endif /* defined(__EMSCRIPTEN__) */ |
|
|
|
|
|
|
|
|
|
|
|
int randombytes(uint8_t *buf, size_t n) |
|
|
|
{ |
|
|
|
int randombytes(uint8_t *buf, size_t n) { |
|
|
|
#if defined(__EMSCRIPTEN__) |
|
|
|
return randombytes_js_randombytes_nodejs(buf, n); |
|
|
|
return randombytes_js_randombytes_nodejs(buf, n); |
|
|
|
#elif defined(__linux__) |
|
|
|
# if defined(SYS_getrandom) |
|
|
|
/* Use getrandom system call */ |
|
|
|
return randombytes_linux_randombytes_getrandom(buf, n); |
|
|
|
# else |
|
|
|
/* When we have enough entropy, we can read from /dev/urandom */ |
|
|
|
return randombytes_linux_randombytes_urandom(buf, n); |
|
|
|
# endif |
|
|
|
#if defined(SYS_getrandom) |
|
|
|
/* Use getrandom system call */ |
|
|
|
return randombytes_linux_randombytes_getrandom(buf, n); |
|
|
|
#else |
|
|
|
/* When we have enough entropy, we can read from /dev/urandom */ |
|
|
|
return randombytes_linux_randombytes_urandom(buf, n); |
|
|
|
#endif |
|
|
|
#elif defined(BSD) |
|
|
|
/* Use arc4random system call */ |
|
|
|
return randombytes_bsd_randombytes(buf, n); |
|
|
|
/* Use arc4random system call */ |
|
|
|
return randombytes_bsd_randombytes(buf, n); |
|
|
|
#elif defined(_WIN32) |
|
|
|
/* Use windows API */ |
|
|
|
return randombytes_win32_randombytes(buf, n); |
|
|
|
/* Use windows API */ |
|
|
|
return randombytes_win32_randombytes(buf, n); |
|
|
|
#else |
|
|
|
# error "randombytes(...) is not supported on this platform" |
|
|
|
#error "randombytes(...) is not supported on this platform" |
|
|
|
#endif |
|
|
|
} |