diff options
Diffstat (limited to 'src/kernel')
| -rw-r--r-- | src/kernel/Makefile | 4 | ||||
| -rw-r--r-- | src/kernel/core/kmain.c | 10 | ||||
| -rw-r--r-- | src/kernel/core/prng.c | 38 | ||||
| -rw-r--r-- | src/kernel/include/prng.h | 9 |
4 files changed, 59 insertions, 2 deletions
diff --git a/src/kernel/Makefile b/src/kernel/Makefile index 88a83e2..1a7c12e 100644 --- a/src/kernel/Makefile +++ b/src/kernel/Makefile @@ -2,14 +2,14 @@ OBJ = core/loader.o core/dbglog.o \ core/gdt.o core/idt.o core/interrupt.o core/context_switch.o core/thread.o \ core/frame.o core/paging.o core/freemem.o core/region.o core/kmalloc.o \ - core/worker.o \ + core/worker.o core/prng.o \ user/vfs.o user/nullfs.o user/process.o user/elf.o user/syscall.o \ dev/pci.o dev/pciide.o \ fs/iso9660.o LIB = ../common/libc/libc.lib ../common/libkogata/libkogata.lib ../common/libalgo/libalgo.lib -CFLAGS = -I ./include -I ../common/include +CFLAGS = -I ./include -I ../common/include -DPRNG_INIT_ENTROPY=$(shell date +%N) LDFLAGS = -T linker.ld -Xlinker -Map=kernel.map diff --git a/src/kernel/core/kmain.c b/src/kernel/core/kmain.c index 5cd71c5..7cdd109 100644 --- a/src/kernel/core/kmain.c +++ b/src/kernel/core/kmain.c @@ -23,10 +23,16 @@ #include <slab_alloc.h> #include <string.h> +#include <prng.h> + #include <dev/pci.h> #include <dev/pciide.h> #include <fs/iso9660.h> +#ifndef PRNG_INIT_ENTROPY +#define PRNG_INIT_ENTROPY 1299733235 +#endif + // ===== FOR TESTS ===== #define TEST_PLACEHOLDER_AFTER_IDT #define TEST_PLACEHOLDER_AFTER_REGION @@ -149,6 +155,10 @@ void kernel_init_stage2(void* data) { // Register FS drivers register_iso9660_driver(); + // Add entropy to prng + uint32_t x = PRNG_INIT_ENTROPY; + prng_add_entropy((uint8_t*)&x, sizeof(x)); + // Parse command line btree_t *cmdline = parse_cmdline((const char*)mbd->cmdline); diff --git a/src/kernel/core/prng.c b/src/kernel/core/prng.c new file mode 100644 index 0000000..d4307b6 --- /dev/null +++ b/src/kernel/core/prng.c @@ -0,0 +1,38 @@ +#include <prng.h> + +#define EPOOLSIZE 2048 + +static uint32_t x = 211; +static int n = 0; +static char entropy[EPOOLSIZE]; +static int entropy_count = 0; +static const uint32_t a = 16807; +static const uint32_t m = 0x7FFFFFFF; + +uint16_t prng_word() { + if (++n == 100) { + n = 0; + if (entropy_count) { + entropy_count--; + x += entropy[entropy_count]; + } + } + x = (x * a) % m; + return x & 0xFFFF; +} + +void prng_bytes(uint8_t* out, size_t nbytes) { + uint16_t *d = (uint16_t*)out; + for (size_t i = 0; i < nbytes / 2; i++) { + d[i] = prng_word(); + } + if (nbytes & 1) out[nbytes-1] = prng_word() & 0xFF; +} + +void prng_add_entropy(const uint8_t* ptr, size_t nbytes) { + while (nbytes-- && entropy_count < EPOOLSIZE - 1) { + entropy[entropy_count++] = *(ptr++); + } +} + +/* vim: set ts=4 sw=4 tw=0 noet :*/ diff --git a/src/kernel/include/prng.h b/src/kernel/include/prng.h new file mode 100644 index 0000000..0a9e036 --- /dev/null +++ b/src/kernel/include/prng.h @@ -0,0 +1,9 @@ +#include <stdint.h> +#include <stddef.h> + +void prng_add_entropy(const uint8_t* ptr, size_t nbytes); // add entropy to generator + +uint16_t prng_word(); +void prng_bytes(uint8_t* out, size_t nbytes); // generate some bytes + +/* vim: set ts=4 sw=4 tw=0 noet :*/ |