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| int do_crypt (const char *infile, const char *key_s, const char *iv_key_s, const char *iv_file_s, const char *fileId_s, int do_encrypt){
/* Allow enough space in output buffer for additional block */
unsigned char inbuf[SIZE_BUF], outbuf[SIZE_BUF + EVP_MAX_BLOCK_LENGTH],
key[16], iv[16];
char outfile[255]="";
int inlen = 0, outlen = 0;
FILE *in = fopen(infile,"rb"),
*out;
if(in==NULL) {
//printf("\ndo_crypt error : file %s not found !",infile);
printTime(var_time);
flog = fopen(LOG_FILE_NAME,"a");
fprintf(flog,"%s\ndo_crypt error : file %s not found !\n",var_time,infile);
fclose(flog);
return 0;
}
if(do_encrypt){ //if encryption case
char iv_fileid_s[40*2+1]="";
unsigned char iv_fileid[40];
strcat(iv_fileid_s,iv_key_s);
strcat(iv_fileid_s,iv_file_s);
strcat(iv_fileid_s,fileId_s);
stringToBytes(iv_fileid_s,iv_fileid);
strcat(outfile,infile);
strcat(outfile,".aes");
out = fopen(outfile,"wb");
if(out==NULL) {
//printf("\ndo_crypt() : an error occured when writing to the file %s !",outfile);
printTime(var_time);
flog = fopen(LOG_FILE_NAME,"a");
fprintf(flog,"%s\ndo_crypt() : an error occured when writing to the file %s !\n",var_time,outfile);
fclose(flog);
return 0;
}
fwrite(iv_fileid, 1, 40, out);
}
else{ //if decryption case
strncpy(outfile,infile,strlen(infile)-4);
out = fopen(outfile,"wb");
if(out==NULL) {
//printf("\ndo_crypt() : an error occured when writing to the file %s !",outfile);
printTime(var_time);
flog = fopen(LOG_FILE_NAME,"a");
fprintf(flog,"%s\ndo_crypt() : an error occured when writing to the file %s !\n",var_time,outfile);
fclose(flog);
return 0;
}
inlen = fread(inbuf, 1, 40, in); //Read IVs+FILE_ID = header (to pass directly to encrypted data)
}
stringToBytes(key_s,key);
stringToBytes(iv_file_s,iv);
EVP_CIPHER_CTX ctx;
EVP_CIPHER_CTX_init(&ctx);
EVP_CipherInit_ex(&ctx, EVP_aes_128_cbc(), NULL, key, iv, do_encrypt);
for(;;)
{
inlen = fread(inbuf, 1, SIZE_BUF, in);
if(inlen <= 0) break;
if(!EVP_CipherUpdate(&ctx, outbuf, &outlen, inbuf, inlen))
{
/* Error */
EVP_CIPHER_CTX_cleanup(&ctx);
fclose(in);
fclose(out);
remove(outfile);
//printf("\ndo_crypt() Error : in EVP_CipherUpdate()");
printTime(var_time);
flog = fopen(LOG_FILE_NAME,"a");
fprintf(flog,"%s\ndo_crypt() Error : in EVP_CipherUpdate()\n",var_time);
fclose(flog);
return 0;
}
fwrite(outbuf, 1, outlen, out);
}
if(!EVP_CipherFinal_ex(&ctx, outbuf, &outlen))
{
/* Error */
EVP_CIPHER_CTX_cleanup(&ctx);
fclose(in);
fclose(out);
remove(outfile);
//printf("\ndo_crypt() Error : in EVP_CipherFinal_ex()");
printTime(var_time);
flog = fopen(LOG_FILE_NAME,"a");
fprintf(flog,"%s\ndo_crypt() Error : in EVP_CipherFinal_ex()\n",var_time);
fclose(flog);
return 0;
}
fwrite(outbuf, 1, outlen, out);
EVP_CIPHER_CTX_cleanup(&ctx);
fclose(in);
fclose(out);
remove(infile);
return 1;
} |
