[英]IDEA/CFB mode decryption and corrupted block
I'm trying to understand the OpenSSL library. 我正在尝试了解OpenSSL库。 I have written a program in C which should decrypt an IDEA/CFB mode encrypted using OpenSSL 1.1.0g. 我用C编写了一个程序,该程序应该解密使用OpenSSL 1.1.0g加密的IDEA / CFB模式。 This is the code so far: 到目前为止,这是代码:
#include <fcntl.h> /* O_RDONLY */
#include <stdio.h> /* printf */
#include <string.h> /* memcpy */
#include <unistd.h> /* read */
#include <openssl/idea.h> /* BF_* */
#include <openssl/evp.h>
#include <openssl/ripemd.h>
#define BUFFER_SIZE 861
unsigned char key[16];
unsigned char iv[8];
int read_file(char *file, unsigned char *buffer);
int main(void)
{
unsigned char buffer[BUFFER_SIZE];
unsigned char cipher_buffer[BUFFER_SIZE];
unsigned char plain[BUFFER_SIZE];
unsigned char iv_buffer[BUFFER_SIZE];
unsigned char hash_buffer[BUFFER_SIZE];
unsigned char final[BUFFER_SIZE];
EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();
EVP_CIPHER *ciph;
char *cipher = "./cipher.bin";
char *key1 = "./key.bin";
//read key
int blah = read_file(key1,buffer);
printf("\nKeylength: %d\n", EVP_CIPHER_key_length(EVP_idea_cfb64()));
printf("IV Length: %d\n",EVP_CIPHER_iv_length(EVP_idea_cfb64()));
printf("\nKEY:");
for(int i = 0;i<16;i++){
key[i] = buffer[i];
printf("%d ", buffer[i]);
}
printf("\nIV : ");
for(int i = 16;i<24;i++){
iv[i] = buffer[i];
printf("%d ", iv[i]);
}
//read cipher
int cipherLen = read_file(cipher,cipher_buffer);
unsigned char cipher_text[cipherLen];
for(int i = 0; i<861;i++){
cipher_text[i] = cipher_buffer[i];
}
int outlen = 0;
unsigned char lastl[BUFFER_SIZE];
int last;
EVP_CIPHER_CTX_init(ctx);
EVP_CipherInit_ex(ctx,EVP_idea_cfb(),NULL,key,iv,0);
EVP_CipherUpdate(ctx,plain,&last,cipher_buffer,BUFFER_SIZE);
EVP_DecryptFinal_ex(ctx,plain,&last);
printf("%s",plain);
return 0;
}
int read_file(char *file, unsigned char *buffer){
int fp = open(file,O_RDONLY);
//printf("fd:%d File: %s\n",fp,file);
if(fp == -1){
perror("File not found");
}
int f_size = lseek (fp , 0 , SEEK_END);
lseek (fp , 0 ,SEEK_SET);
printf(" f_size:%d\n",f_size);
read(fp,buffer,BUFFER_SIZE);
//printf("lol:%d\n", f_size);
return f_size;
}
The problem I have is that when I print the result everything is fine but the first block of the text is corrupted ( the first 8 byte) I think it has something to do with the CFB mode, but I can't wrap my head around this. 我的问题是,当我打印结果时,一切都很好,但是文本的第一块已损坏(前8个字节),我认为这与CFB模式有关,但是我无法解决问题这个。 :( :(
This is the Output: Output 这是输出: 输出
And these are the two files (cipher.bin and key.bin): 这是两个文件(cipher.bin和key.bin):
Big mistake on my side 我这边的大错误
I read the keys out of the file and messed up with the index... 我从文件中读取了密钥并弄乱了索引...
the IV vector was corrupted IV向量已损坏
int j=0;
for(int i = 16;i<24;i++){
iv[j] = buffer[i];
printf("0x%02x,", iv[i]);
j++;
}
That fixed it 修好了
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