rixxc/x25519_agent
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use later jasmin version that can issue proper syscalls and can generate asm code without ret

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This commit is contained in:
Aaron Kaiser
2024-08-23 10:58:24 +02:00
parent 36ae72a8d9
commit b7af39ff80
7 changed files with 28 additions and 205 deletions
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1
.gitignore vendored
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@@ -1,3 +1,4 @@
build
result
*.o
.direnv

13
Makefile
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@@ -2,13 +2,15 @@ JC ?= jasminc
CC ?= gcc
MAKE ?= make
JASMIN_ARGS = -protect-calls -return-address-kind mmx
.PHONY: clean run
all: build
@true
build: build/agent.o syscall/jasmin_syscall.o
ar -crs build/libagent.a build/agent.o syscall/jasmin_syscall.o
build: build/agent.o
ar -crs build/libagent.a build/agent.o
build/%.o: build/%.S
$(CC) $< -c -o $@
@@ -18,7 +20,6 @@ clean:
$(MAKE) -C syscall clean
build/%.S: src/%.jazz
$(JC) $< -o $@
syscall/jasmin_syscall.o: syscall/jasmin_syscall.c syscall/jasmin_syscall.h
$(MAKE) -C syscall
$(JC) $(JASMIN_ARGS) $< -o $@
# remove the remaining ret calls to make sure that we don't execute any return. Those returns should not be called anyways due to the infinit loop
sed -i 's/ret/hlt/g' $@

6
default.nix
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@@ -2,10 +2,10 @@
with pkgs;
let
jasmin-src = fetchFromGitHub {
owner = "Rixxc";
owner = "jasmin-lang";
repo = "jasmin";
rev = "783aea97836f5ddf7b62de24ab94768cb606adf8";
hash = "sha256-5XXZ2IYXCixJHaswdYkG8ivh3fIftaibOgkpz2TKGMI=";
rev = "4d42c212b924ad7553c2eab49d337fd128ad629b";
hash = "sha256-Ve9Eezpvi1wynlqQxO4KDSqw13MDXQmR8NjOS3PHWzg=";
};
jasmin-drv = callPackage "${jasmin-src}/default.nix" { inherit pkgs; };

23
src/agent.jazz
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@@ -20,9 +20,10 @@ inline fn extract_ipc_id(reg u64 sync_mem) -> reg u64 {
inline fn generate_keypair(reg u64 shared_mem sync_mem private_mem, stack u64 key_id) -> stack u64 {
inline int i;
stack u8[32] key;
reg u64 addr idptr pkptr;
reg u64 addr idptr pkptr flag num_bytes;
key = #randombytes(key);
flag = 0;
key, num_bytes = #randombytes(key, flag);
key[0] &= 248;
key[31] &= 127;
key[31] |= 64;
@@ -78,17 +79,22 @@ inline fn x25519(reg u64 shared_mem sync_mem private_mem) {
}
export fn agent_start(reg u64 shared_mem sync_mem private_mem) {
stack u8[8] unused;
stack u64 key_id;
reg u64 futex_op, val, timeout, uaddr2, val3, woken_up;
key_id = 0;
() = #spill(shared_mem, sync_mem, private_mem);
while (true) {
unused = unused;
() = #unspill(sync_mem);
unused = #read(unused, sync_mem);
futex_op = 0;
val = 0;
timeout = 0;
uaddr2 = 0;
val3 = 0;
woken_up = #futex(sync_mem, futex_op, val, timeout, uaddr2, val3);
() = #unspill(shared_mem, sync_mem, private_mem);
@@ -109,6 +115,11 @@ export fn agent_start(reg u64 shared_mem sync_mem private_mem) {
() = #unspill(sync_mem);
unused = #write(unused, sync_mem);
futex_op = 1;
val = 1;
timeout = 0;
uaddr2 = 0;
val3 = 0;
woken_up = #futex(sync_mem, futex_op, val, timeout, uaddr2, val3);
}
}

8
syscall/Makefile
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@@ -1,8 +0,0 @@
.PHONY: clean
all: jasmin_syscall.o
jasmin_syscall.o: jasmin_syscall.c jasmin_syscall.h
clean:
rm jasmin_syscall.o || true

162
syscall/jasmin_syscall.c
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@@ -1,162 +0,0 @@
#include "jasmin_syscall.h"
#if defined(__linux__)
#include <errno.h>
#include <fcntl.h>
#include <linux/futex.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/random.h>
#include <sys/syscall.h>
#include <unistd.h>
// uint8_t *__jasmin_syscall_randombytes__(uint8_t *_x, uint64_t xlen) {
// int i;
// uint8_t *x = _x;
//
// printf("%lx:\n", x);
//
// for (i = 0; i < xlen; i++) {
// printf("%02X", _x[i]);
// }
// printf("\n");
//
// return _x;
// }
//
uint8_t* __jasmin_syscall_randombytes__(uint8_t* _x, uint64_t xlen)
{
int i;
uint8_t* x = _x;
while (xlen > 0) {
if (xlen < 1048576) i = xlen; else i = 1048576;
i = getrandom(x,i,0);
if (i < 1) {
sleep(1);
continue;
}
x += i;
xlen -= i;
}
return _x;
}
// uint64_t __jasmin_syscall_open__(uint8_t* x, uint64_t xlen)
// {
// uint8_t filename[xlen + 1];
// memcpy(filename, x, xlen);
// filename[xlen] = 0;
//
// return (uint64_t)open(filename, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR);
// }
//
// uint8_t __jasmin_syscall_close__(uint64_t fd)
// {
// int success = close(fd);
//
// if (success == 0) {
// return 1;
// } else {
// return 0;
// }
// }
uint64_t __jasmin_syscall_open__(uint8_t *x, uint64_t xlen) {
uint8_t *mem =
(uint8_t *)mmap(NULL, 1024, PROT_READ | PROT_WRITE, MAP_SHARED, 3, 0);
if (mem == NULL) {
puts("mem error");
exit(1);
}
uintptr_t addr = (uintptr_t)(mem - 4096);
void *futex_mem =
mmap((void *)addr, 1024, PROT_READ | PROT_WRITE, MAP_SHARED, 4, 0);
if ((uintptr_t)futex_mem != addr) {
puts("mem error 2");
exit(1);
}
return (uint64_t)mem;
}
// uint8_t* __jasmin_syscall_write__(uint8_t* _x, uint64_t xlen, uint64_t fd)
// {
// size_t i;
// uint8_t* x = _x;
//
// while (xlen > 0) {
// i = write(fd, x, xlen);
// if (i < 1) {
// continue;
// }
// x += i;
// xlen -= i;
// }
//
// return _x;
// }
uint8_t *__jasmin_syscall_read__(uint8_t *_x, uint64_t xlen, uint64_t fd) {
uint32_t *addr = (uint32_t *)(uintptr_t)fd;
long ret = syscall(SYS_futex, addr, FUTEX_WAIT, 0, NULL, NULL, 0);
if (ret == -1) {
printf("Agent futex error: %d\n", errno);
perror("futex");
}
return _x;
}
uint8_t *__jasmin_syscall_write__(uint8_t *_x, uint64_t xlen, uint64_t fd) {
uint32_t *addr = (uint32_t *)(uintptr_t)fd;
int woken_up = 0;
while (woken_up == 0) {
woken_up = syscall(SYS_futex, addr, FUTEX_WAKE, 1, NULL, NULL, 0);
}
return _x;
}
// uint8_t* __jasmin_syscall_read__(uint8_t* _x, uint64_t xlen, uint64_t fd)
// {
// size_t i;
// uint8_t* x = _x;
//
// i = read(fd, x, xlen);
// if (i < 1) {
// // Do something
// perror("Something went wrong while reading the file");
// }
// x += i;
// xlen -= i;
//
// memset(x, 0, xlen);
//
// return _x;
// }
#endif
#if defined(__APPLE__)
#include <stdlib.h>
#if !(defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && \
__MAC_OS_X_VERSION_MIN_REQUIRED >= 101200)
#error "macOS version not supported (>= 10.12)"
#endif
uint8_t *__jasmin_syscall_randombytes__(uint8_t *x, uint64_t xlen) {
arc4random_buf(x, xlen);
return x;
}
#endif

20
syscall/jasmin_syscall.h
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@@ -1,20 +0,0 @@
#include <stdint.h>
#ifndef JASMIN_SYSCALL
#define JASMIN_SYSCALL
/* FIXME this need xlen to be Uptr */
uint8_t* __jasmin_syscall_randombytes__(uint8_t* x, uint64_t xlen)
asm("__jasmin_syscall_randombytes__");
uint64_t __jasmin_syscall_open__(uint8_t* x, uint64_t xlen)
asm("__jasmin_syscall_open__");
uint8_t __jasmin_syscall_close__(uint64_t fd)
asm("__jasmin_syscall_close__");
uint8_t* __jasmin_syscall_write__(uint8_t* x, uint64_t xlen, uint64_t fd)
asm("__jasmin_syscall_write__");
uint8_t* __jasmin_syscall_read__(uint8_t* x, uint64_t xlen, uint64_t fd)
asm("__jasmin_syscall_read__");
#endif