while (*str) { val = val * 2 + (*str++) - '0'; }
时间: 2024-05-22 10:16:52 浏览: 6
This code is a loop that converts a binary string into a decimal integer.
The loop iterates through each character in the string, until it reaches the null terminator (represented by the condition "*str", which means "the value at the memory location pointed to by str").
For each character, the code multiplies the current value of "val" by 2, and then adds the value of the current character (which is converted from ASCII to its corresponding integer value by subtracting the ASCII value of '0').
At the end of the loop, the variable "val" contains the decimal equivalent of the binary string.
相关问题
def fpe(frame_phone_input,root): phone_input = frame_phone_input.get() def fpe_encrypt(plaintext, key, radix=10, rounds=4): # 对明文进行哈希 hash_val = hmac.new(key.encode(), plaintext.encode(), hashlib.sha256).digest() # 将哈希值转换为整数 num_val = int.from_bytes(hash_val, byteorder='big') # 将整数转换为指定进制的字符串 str_val = '' while num_val > 0: num_val, rem = divmod(num_val, radix) str_val = str(rem) + str_val # 对字符串进行 FPE 加密 for i in range(rounds): str_val = ''.join([chr((ord(c) - ord('0') + i) % (radix - 1) + ord('0')) for c in str_val]) # 返回加密后的字符串 return str_val key = 'my-secret-key' encrypted = fpe_encrypt(phone_input, key) phone_label = tk.Label(root, text=("加密后的手机号:", encrypted), font=("微软雅黑 -20")) phone_label.place(x=500, y=560)怎么把加密后的手机号分三行显示
你可以使用字符串的切片功能将加密后的手机号分成三段,然后分别显示在三个 Label 中。下面是一个修改过的代码示例:
```
def fpe(frame_phone_input, root):
phone_input = frame_phone_input.get()
def fpe_encrypt(plaintext, key, radix=10, rounds=4):
# 对明文进行哈希
hash_val = hmac.new(key.encode(), plaintext.encode(), hashlib.sha256).digest()
# 将哈希值转换为整数
num_val = int.from_bytes(hash_val, byteorder='big')
# 将整数转换为指定进制的字符串
str_val = ''
while num_val > 0:
num_val, rem = divmod(num_val, radix)
str_val = str(rem) + str_val
# 对字符串进行 FPE 加密
for i in range(rounds):
str_val = ''.join([chr((ord(c) - ord('0') + i) % (radix - 1) + ord('0')) for c in str_val])
# 返回加密后的字符串
return str_val
key = 'my-secret-key'
encrypted = fpe_encrypt(phone_input, key)
# 将加密后的手机号分成三段
chunk_size = len(encrypted) // 3
chunk1 = encrypted[:chunk_size]
chunk2 = encrypted[chunk_size:2*chunk_size]
chunk3 = encrypted[2*chunk_size:]
# 在三个 Label 中分别显示加密后的手机号的三段
phone_label1 = tk.Label(root, text=("加密后的手机号:", chunk1), font=("微软雅黑 -20"))
phone_label1.place(x=500, y=560)
phone_label2 = tk.Label(root, text=chunk2, font=("微软雅黑 -20"))
phone_label2.place(x=500, y=590)
phone_label3 = tk.Label(root, text=chunk3, font=("微软雅黑 -20"))
phone_label3.place(x=500, y=620)
```
这样,加密后的手机号就会分成三行显示。
if(strcmp(lib->name,"lib.so.6")==0) return; for(int j = 0;j < lib->depcnt; ++j) RelocLibrary(lib->dep[j], mode); Elf64_Sym *sym=NULL; Elf64_Rela *frel=NULL; int relsz=0; char *str=NULL; if(lib->dynInfo[DT_SYMTAB]) sym=(typeof(sym))lib->dynInfo[DT_SYMTAB]->d_un.d_ptr; if(lib->dynInfo[DT_JMPREL]) frel=(typeof(frel))lib->dynInfo[DT_JMPREL]->d_un.d_ptr; if(lib->dynInfo[DT_PLTRELSZ]) relsz=lib->dynInfo[DT_PLTRELSZ]->d_un.d_val/sizeof(Elf64_Rela); if(lib->dynInfo[DT_STRTAB]) str=(char*)lib->dynInfo[DT_STRTAB]->d_un.d_ptr; for(int i=0;i<relsz;++i,++frel){ Elf64_Addr *got=(void*)(lib->addr+frel->r_offset); if(mode == RTLD_LAZY){ *got += lib->addr; continue; } void *result = NULL; for(int j=0;j<lib->depcnt;++j){ void *tmp=symbolLookup(lib->dep[j],&str[sym[ELF64_R_SYM(frel->r_info)].st_name]); if(tmp!=NULL){ result=tmp+frel->r_addend; break; } } *(uint64_t*)(lib->addr+frel->r_offset)=(uint64_t)result; }将这段代码用c语言重新实现
抱歉,我是一个自然语言处理的AI,无法直接生成代码,但我可以提供一个大致的思路供您参考:
首先,需要包含一些头文件,如:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <elf.h>
```
然后,需要定义一些数据结构,如:
```c
typedef struct {
char* name; // 库名
void* addr; // 库地址
int depcnt; // 依赖库数量
struct Library** dep; // 依赖库列表
Elf64_Dyn** dynInfo; // 动态信息
} Library;
Library** libraries = NULL;
int libcnt = 0;
```
接着,需要实现一些函数,如:
```c
void RelocLibrary(Library* lib, int mode) {
if (strcmp(lib->name, "lib.so.6") == 0) {
return;
}
for (int j = 0; j < lib->depcnt; ++j) {
RelocLibrary(lib->dep[j], mode);
}
Elf64_Sym* sym = NULL;
Elf64_Rela* frel = NULL;
int relsz = 0;
char* str = NULL;
if (lib->dynInfo[DT_SYMTAB]) {
sym = (typeof(sym))lib->dynInfo[DT_SYMTAB]->d_un.d_ptr;
}
if (lib->dynInfo[DT_JMPREL]) {
frel = (typeof(frel))lib->dynInfo[DT_JMPREL]->d_un.d_ptr;
}
if (lib->dynInfo[DT_PLTRELSZ]) {
relsz = lib->dynInfo[DT_PLTRELSZ]->d_un.d_val / sizeof(Elf64_Rela);
}
if (lib->dynInfo[DT_STRTAB]) {
str = (char*)lib->dynInfo[DT_STRTAB]->d_un.d_ptr;
}
for (int i = 0; i < relsz; ++i, ++frel) {
Elf64_Addr* got = (void*)(lib->addr + frel->r_offset);
if (mode == RTLD_LAZY) {
*got += lib->addr;
continue;
}
void* result = NULL;
for (int j = 0; j < lib->depcnt; ++j) {
void* tmp = symbolLookup(lib->dep[j], &str[sym[ELF64_R_SYM(frel->r_info)].st_name]);
if (tmp != NULL) {
result = tmp + frel->r_addend;
break;
}
}
*(uint64_t*)(lib->addr + frel->r_offset) = (uint64_t)result;
}
}
void* symbolLookup(Library* lib, const char* name) {
Elf64_Sym* sym = NULL;
char* str = NULL;
if (lib->dynInfo[DT_SYMTAB]) {
sym = (typeof(sym))lib->dynInfo[DT_SYMTAB]->d_un.d_ptr;
}
if (lib->dynInfo[DT_STRTAB]) {
str = (char*)lib->dynInfo[DT_STRTAB]->d_un.d_ptr;
}
for (int i = 0; i < lib->dynInfo[DT_PLTRELSZ]->d_un.d_val / sizeof(Elf64_Rela); ++i) {
if (ELF64_ST_TYPE(sym[i].st_info) != STT_FUNC) {
continue;
}
if (strcmp(&str[sym[i].st_name], name) == 0) {
return (void*)(lib->addr + sym[i].st_value);
}
}
return NULL;
}
Library* loadLibrary(const char* name, int mode) {
char buf[256];
Library* lib = (Library*)malloc(sizeof(Library));
lib->name = strdup(name);
snprintf(buf, sizeof(buf), "/usr/lib/%s", name);
FILE* fp = fopen(buf, "rb");
if (fp == NULL) {
free(lib);
return NULL;
}
fseek(fp, 0, SEEK_END);
size_t size = ftell(fp);
fseek(fp, 0, SEEK_SET);
void* addr = malloc(size);
fread(addr, 1, size, fp);
fclose(fp);
Elf64_Ehdr* ehdr = (Elf64_Ehdr*)addr;
Elf64_Phdr* phdr = (Elf64_Phdr*)((char*)ehdr + ehdr->e_phoff);
for (int i = 0; i < ehdr->e_phnum; ++i) {
if (phdr[i].p_type == PT_LOAD) {
memcpy((void*)phdr[i].p_vaddr, (void*)((char*)addr + phdr[i].p_offset), phdr[i].p_filesz);
memset((void*)(phdr[i].p_vaddr + phdr[i].p_filesz), 0, phdr[i].p_memsz - phdr[i].p_filesz);
}
}
Elf64_Dyn* dyn = (Elf64_Dyn*)((char*)ehdr + ehdr->e_dynamic);
lib->dynInfo = (Elf64_Dyn**)malloc(sizeof(Elf64_Dyn*) * DT_NUM);
memset(lib->dynInfo, 0, sizeof(Elf64_Dyn*) * DT_NUM);
while (dyn->d_tag != DT_NULL) {
if (dyn->d_tag < DT_NUM) {
lib->dynInfo[dyn->d_tag] = dyn;
}
dyn++;
}
lib->addr = addr;
lib->depcnt = 0;
lib->dep = NULL;
if (lib->dynInfo[DT_NEEDED]) {
char* str = (char*)lib->dynInfo[DT_STRTAB]->d_un.d_ptr;
char* ptr = (char*)lib->dynInfo[DT_NEEDED]->d_un.d_ptr;
while (*ptr) {
char* depname = ptr;
ptr += strlen(depname) + 1;
if (mode == RTLD_LAZY) {
if (strcmp(depname, "libpthread.so.0") == 0 || strcmp(depname, "libc.so.6") == 0) {
continue;
}
}
if (strcmp(depname, lib->name) == 0) {
continue;
}
Library* dep = loadLibrary(depname, mode);
if (dep == NULL) {
fprintf(stderr, "cannot load library '%s'\n", depname);
exit(1);
}
lib->dep = (Library**)realloc(lib->dep, sizeof(Library*) * (lib->depcnt + 1));
lib->dep[lib->depcnt] = dep;
lib->depcnt++;
}
}
libraries = (Library**)realloc(libraries, sizeof(Library*) * (libcnt + 1));
libraries[libcnt] = lib;
libcnt++;
return lib;
}
void unloadLibrary(Library* lib) {
for (int i = 0; i < lib->depcnt; ++i) {
unloadLibrary(lib->dep[i]);
}
free(lib->dep);
free(lib->dynInfo);
free(lib->name);
free(lib->addr);
free(lib);
}
```
最后,可以在主函数中调用这些函数,如:
```c
int main() {
Library* lib = loadLibrary("libtest.so", RTLD_NOW);
RelocLibrary(lib, RTLD_NOW);
void (*func)() = symbolLookup(lib, "test");
if (func != NULL) {
func();
}
unloadLibrary(lib);
return 0;
}
```
当然,这只是一个大致的实现思路,具体实现还需要根据需求进行适当的修改和调整。