3 files changed, 263 insertions, 4 deletions

diff --git a/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/Makefile b/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/Makefile
index aec0c03..c45c8d8 100644
--- a/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/Makefile
+++ b/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/Makefile
@@ -73,6 +73,9 @@ c_utils.o: c_utils.c
 lib_timing.so: c_timing.c
 	$(CC) -o $@ -shared $(CFLAGS) -Wl,-soname,lib_timing.so $<
 
+lib_preload.so: preload.c
+	$(CC) -shared -fPIC -ldl $< -o $@
+
 lib_csignals.so: c_signals.c
 	$(CC) -o $@ -shared $(CFLAGS) -pthread -lpthread -Wl,-soname,lib_csignals.so $<
 
@@ -99,7 +102,7 @@ boringssl: boringssl_provider.so
 lib_boringssl.so:
 	cp $(PROJECT_ROOT_PATH)/ext/boringssl/build/crypto/libcrypto.so lib_boringssl.so
 
-boringssl_provider.so: boringssl.o c_utils.o | lib_timing.so lib_csignals.so lib_boringssl.so
+boringssl_provider.so: boringssl.o c_utils.o | lib_timing.so lib_csignals.so lib_preload.so lib_boringssl.so
 	$(CC) $(LFLAGS) -o $@ -Wl,-rpath,'$$ORIGIN/lib' $^ -L. lib_boringssl.so -l:lib_timing.so -l:lib_csignals.so
 
 boringssl.o: boringssl.c
@@ -109,7 +112,7 @@ boringssl.o: boringssl.c
 # libgcrypt shim
 gcrypt: gcrypt_provider.so
 
-gcrypt_provider.so: gcrypt.o c_utils.o | lib_timing.so lib_csignals.so
+gcrypt_provider.so: gcrypt.o c_utils.o | lib_timing.so lib_csignals.so lib_preload.so
 	$(CC) $(LFLAGS) -o $@ -Wl,-rpath,'$$ORIGIN/lib' $^ -L. -pthread -lpthread $(shell libgcrypt-config --libs) -l:lib_timing.so -l:lib_csignals.so
 
 gcrypt.o: gcrypt.c
@@ -192,7 +195,7 @@ libressl: libressl_provider.so
 lib_libressl.so:
 	cp $(PROJECT_ROOT_PATH)/ext/libressl/build/crypto/libcrypto.so lib_libressl.so
 
-libressl_provider.so: libressl.o c_utils.o | lib_timing.so lib_csignals.so lib_libressl.so
+libressl_provider.so: libressl.o c_utils.o | lib_timing.so lib_csignals.so lib_preload.so lib_libressl.so
 	$(CC) $(LFLAGS) -o $@ -Wl,-rpath,'$$ORIGIN/lib' $^ -L. lib_libressl.so -l:lib_timing.so -l:lib_csignals.so
 
 libressl.o: libressl.c
diff --git a/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/gcrypt.c b/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/gcrypt.c
index 795c30a..7be778c 100644
--- a/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/gcrypt.c
+++ b/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/gcrypt.c
@@ -42,6 +42,7 @@ JNIEXPORT void JNICALL Java_cz_crcs_ectester_standalone_libs_jni_NativeProvider_
     gcry_control(GCRYCTL_DISABLE_SECMEM, 0);
     //gcry_control(GCRYCTL_SET_DEBUG_FLAGS, 1);
     gcry_control(GCRYCTL_ENABLE_QUICK_RANDOM, 0);
+	gcry_control(GCRYCTL_SET_PREFERRED_RNG_TYPE, GCRY_RNG_TYPE_SYSTEM);
     gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
 
     INIT_PROVIDER(env, provider_class);
@@ -651,4 +652,4 @@ release_init:
     gcry_sexp_release(pub_sexp);
     gcry_sexp_release(data_sexp);
     return result;
-}
\ No newline at end of file
+}
diff --git a/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/preload.c b/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/preload.c
new file mode 100644
index 0000000..ff7b67b
--- /dev/null
+++ b/standalone/src/main/resources/cz/crcs/ectester/standalone/libs/jni/preload.c
@@ -0,0 +1,255 @@
+#define _GNU_SOURCE
+
+#include <dlfcn.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/random.h>
+#include <sys/syscall.h>
+
+typedef int (*open_t)(const char *pathname, int flags, ...);
+static open_t real_open;
+typedef int (*openat_t)(int fd, const char *pathname, int flags, ...);
+static openat_t real_openat;
+typedef ssize_t (*read_t)(int fd, void *buf, size_t count);
+static read_t real_read;
+typedef FILE *(*fopen_t)(const char *pathname, const char *mode);
+static fopen_t real_fopen;
+typedef size_t (*fread_t)(void *ptr, size_t size, size_t nmemb, FILE *stream);
+static fread_t real_fread;
+typedef ssize_t (*getrandom_t)(void *buf, size_t buflen, unsigned int flags);
+static getrandom_t real_getrandom;
+typedef int (*getentropy_t)(void *buffer, size_t length);
+static getentropy_t real_getentropy;
+typedef long (*syscall_t)(long number, ...);
+static syscall_t real_syscall;
+typedef uint32_t (*arc4random_t)(void);
+static arc4random_t real_arc4random;
+typedef uint32_t (*arc4random_uniform_t)(uint32_t upper_bound);
+static arc4random_uniform_t real_arc4random_uniform;
+typedef void (*arc4random_buf_t)(void *buf, size_t n);
+static arc4random_buf_t real_arc4random_buf;
+
+static int *random_fds = NULL;
+static size_t random_fds_used = 0;
+static size_t random_fds_allocd = 0;
+
+void check_random_fds() {
+	if (random_fds_allocd == 0) {
+		random_fds_allocd = 10;
+		random_fds = calloc(random_fds_allocd, sizeof(int));
+	} else if (random_fds_allocd == random_fds_used) {
+		random_fds_allocd *= 2;
+		random_fds = realloc(random_fds, random_fds_allocd * sizeof(int));
+	}
+}
+
+void store_random_fd(int fd) {
+	check_random_fds();
+	random_fds[random_fds_used++] = fd;
+}
+
+int open(const char *pathname, int flags, ...) {
+	if (!real_open) {
+		real_open = dlsym(RTLD_NEXT, "open");
+	}
+
+	va_list args;
+	va_start(args, flags);
+	int mode = va_arg(args, int);
+	va_end(args);
+
+	int result = real_open(pathname, flags, mode);
+	if (strcmp(pathname, "/dev/random") == 0 || strcmp(pathname, "/dev/urandom") == 0) {
+		fprintf(stderr, "called open(%s, %i, %i)\n", pathname, flags, mode);
+		store_random_fd(result);
+	}
+	return result;
+}
+
+int openat(int fd, const char *pathname, int flags, ...) {
+	if (!real_openat) {
+		real_openat = dlsym(RTLD_NEXT, "openat");
+	}
+
+	va_list args;
+	va_start(args, flags);
+	int mode = va_arg(args, int);
+	va_end(args);
+
+	int result = real_openat(fd, pathname, flags, mode);
+	if (strcmp(pathname, "/dev/random") == 0 || strcmp(pathname, "/dev/urandom") == 0) {
+		fprintf(stderr, "called openat(%s, %i, %i)\n", pathname, flags, mode);
+		store_random_fd(result);
+	}
+	return result;
+}
+
+ssize_t read(int fd, void *buf, size_t count) {
+	if (!real_read) {
+		real_read = dlsym(RTLD_NEXT, "read");
+	}
+
+	for (int i = 0; i < random_fds_used; ++i) {
+		int random_fd = random_fds[i];
+		if (random_fd == fd) {
+			fprintf(stderr, "read from random\n");
+			uint8_t *buffer = (uint8_t*)buf;
+			for (size_t c = 0; c < count; ++c) {
+				buffer[c] = (uint8_t)0x00;
+			}
+			return count;
+		}
+	}
+
+	return real_read(fd, buf, count);
+}
+
+static FILE **random_files = NULL;
+static size_t random_files_used = 0;
+static size_t random_files_allocd = 0;
+
+void check_random_files() {
+	if (random_files_allocd == 0) {
+		random_files_allocd = 10;
+		random_files = calloc(random_files_allocd, sizeof(FILE *));
+	} else if (random_files_allocd == random_files_used) {
+		random_files_allocd *= 2;
+		random_files = realloc(random_files, random_files_allocd * sizeof(FILE*));
+	}
+}
+
+void store_random_file(FILE *file) {
+	check_random_files();
+	random_files[random_files_used++] = file;
+}
+
+FILE *fopen(const char *pathname, const char *mode) {
+	if (!real_fopen) {
+		real_fopen = dlsym(RTLD_NEXT, "fopen");
+	}
+
+	FILE *result = real_fopen(pathname, mode);
+
+	if (strcmp(pathname, "/dev/random") == 0 || strcmp(pathname, "/dev/urandom") == 0) {
+		fprintf(stderr, "called fopen(%s, %s)\n", pathname, mode);
+		store_random_file(result);
+	}
+	return result;
+}
+
+size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream) {
+	if (!real_fread) {
+		real_fread = dlsym(RTLD_NEXT, "fread");
+	}
+
+	for (int i = 0; i < random_files_used; ++i) {
+		FILE *random_file = random_files[i];
+		if (random_file == stream) {
+			fprintf(stderr, "fread from random\n");
+			uint8_t *buffer = (uint8_t*)ptr;
+			for (size_t c = 0; c < size * nmemb; ++c) {
+				buffer[c] = (uint8_t)0x00;
+			}
+			return size * nmemb;
+		}
+	}
+
+	return real_fread(ptr, size, nmemb, stream);
+}
+
+ssize_t getrandom(void *buf, size_t buflen, unsigned int flags) {
+	if (!real_getrandom) {
+		real_getrandom = dlsym(RTLD_NEXT, "getrandom");
+	}
+
+	fprintf(stderr, "called getrandom(*, %lu, %u)\n", buflen, flags);
+	uint8_t *buffer = (uint8_t*)buf;
+	for (size_t i = 0; i < buflen; ++i) {
+		buffer[i] = (uint8_t)0x00;
+	}
+	return buflen;
+}
+
+int getentropy(void *buffer, size_t length) {
+	if (!real_getentropy) {
+		real_getentropy = dlsym(RTLD_NEXT, "getentropy");
+	}
+
+	fprintf(stderr, "called getentropy(*, %lu)\n", length);
+	uint8_t *buf = (uint8_t*)buffer;
+	for (size_t i = 0; i < length; ++i) {
+		buf[i] = (uint8_t)0x00;
+	}
+	return 0;
+}
+
+long syscall(long number, ...) {
+	if (!real_syscall) {
+		real_syscall = dlsym(RTLD_NEXT, "syscall");
+	}
+	va_list args;
+
+	va_start(args, number);
+	long int a0 = va_arg(args, long int);
+	long int a1 = va_arg(args, long int);
+	long int a2 = va_arg(args, long int);
+	long int a3 = va_arg(args, long int);
+	long int a4 = va_arg(args, long int);
+	long int a5 = va_arg(args, long int);
+	va_end(args);
+
+	if (number == SYS_getrandom) {
+		fprintf(stderr, "called syscall(getrandom, %li, %li, %li, %li, %li, %li)\n", a0, a1, a2, a3, a4, a5);
+		uint8_t *buf = (uint8_t*)a0;
+		long n = a1;
+		for (size_t i = 0; i < n; ++i) {
+			buf[i] = (uint8_t)0x00;
+		}
+		return n;
+	}
+	return real_syscall(number, a0, a1, a2, a3, a4, a5);
+}
+
+uint32_t arc4random(void) {
+	if (!real_arc4random) {
+		real_arc4random = dlsym(RTLD_NEXT, "arc4random");
+	}
+
+	fprintf(stderr, "called arc4random\n");
+	return 0;
+}
+
+uint32_t arc4random_uniform(uint32_t upper_bound) {
+	if (!real_arc4random_uniform) {
+		real_arc4random_uniform = dlsym(RTLD_NEXT, "arc4random_uniform");
+	}
+
+	fprintf(stderr, "called arc4random_uniform(%u)\n", upper_bound);
+	return 0;
+}
+
+void arc4random_buf(void *buf, size_t n) {
+	if (!real_arc4random_buf) {
+		real_arc4random_buf = dlsym(RTLD_NEXT, "arc4random_buf");
+	}
+
+	fprintf(stderr, "called arc4random_buf(%p, %lu)\n", buf, n);
+	uint8_t *buffer = (uint8_t*)buf;
+	for (size_t i = 0; i < n; ++i) {
+		buffer[i] = (uint8_t)0x00;
+	}
+}
+
+
+void __attribute__((destructor)) dealloc() {
+	if (random_fds != NULL) {
+		free(random_fds);
+	}
+	if (random_files != NULL) {
+		free(random_files);
+	}
+}