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因为是简单的xor，所以加密与解密是同一个算法。
但是有时会出现丢数据的现象，'6'这个数据有时会丢。
不知是我这里的问题，还是别的问题。
function TForm_pwdfile.setpwdfile(soure_filename:string;dest_filename:string;flag:integer):string;
var
soure_file,dest_file:file;
buffer: byte;
bytesread,totalread,byteswritten,fsize:integer;
soure_str:string ;
pwd_str:string;
pwd:byte;
begin
assignfile(soure_file,soure_filename);
reset(soure_file,1);
assignfile(dest_file,dest_filename);
try
rewrite(dest_file,1);
try
try
if flag=0 then
begin
pwd:=RandomRange(10,254) ;//------？？随机数，解密时不会出错吗？ ，这里改为RandomRange(32,254) ，就好了
buffer:=pwd;
pwd_str:=char(pwd );
blockwrite(dest_file,buffer,1,byteswritten);
end
else
begin
blockread(soure_file,buffer,sizeof(buffer),bytesread);
pwd:=buffer;
end;
totalread:=0;
fsize:=filesize(soure_file);
repeat
blockread(soure_file,buffer,sizeof(buffer),bytesread);
if bytesread>0 then
begin
buffer:=setpasswrod(buffer ,pwd );
blockwrite(dest_file,buffer,bytesread,byteswritten);
if bytesread<>byteswritten then
raise exception.Create('复制文件出错！')
else
begin
totalread:=totalread+bytesread;
end;
end
until bytesread=0;
except
erase(dest_file);
raise;
end;
finally
closefile(dest_file);
closefile(soure_file);
end;
finally
end;
function TForm_pwdfile.setpasswrod(sou_str:variant;pwd_str:variant):variant;
var
result_str:variant;
soure_str,pswd_str:variant;
begin
soure_str:=sou_str;
pswd_str:=pwd_str;
result_str:=soure_str xor pswd_str;
result:=result_str;
end;
附:同事的用C语言进行的对应加密/解密算法。
经我的算法加密后的文件，在他那里发现问题。 到底是我的问题，还是他的问题呢？
int
my_encrypt(file1,file2)
char *file1;
char *file2;
{
FILE *fp,*fp2;
char ch,ch1;
if((fp=fopen(file1,"r"
) == NULL){
return (-1);
}
if((fp2=fopen(file2,"w") == NULL){
return (-1);
}
ch = fgetc(fp);
ch1 = fgetc(fp);
while (!feof(fp)) {
ch1 = ch1 ^ ch;
fputc(ch1,fp2);
ch1 = fgetc(fp);
}
fclose(fp);
fclose(fp2);
return 0;
}
int
my_crypt(file1,file2,ch)
char *file1;
char *file2;
char ch;
{
FILE *fp,*fp2;
char ch1;
int i;
if((fp=fopen(file1,"r") == NULL){
return (-1);
}
if((fp2=fopen(file2,"w") == NULL){
return (-1);
}
fputc(ch,fp2);
ch1 = fgetc(fp);
while (!feof(fp)) {
ch1 = ch1 ^ ch;
fputc(ch1,fp2);
ch1 = fgetc(fp);
}
fclose(fp);
fclose(fp2);
return 0;
}
发分。。
但是有时会出现丢数据的现象，'6'这个数据有时会丢。
不知是我这里的问题，还是别的问题。
function TForm_pwdfile.setpwdfile(soure_filename:string;dest_filename:string;flag:integer):string;
var
soure_file,dest_file:file;
buffer: byte;
bytesread,totalread,byteswritten,fsize:integer;
soure_str:string ;
pwd_str:string;
pwd:byte;
begin
assignfile(soure_file,soure_filename);
reset(soure_file,1);
assignfile(dest_file,dest_filename);
try
rewrite(dest_file,1);
try
try
if flag=0 then
begin
pwd:=RandomRange(10,254) ;//------？？随机数，解密时不会出错吗？ ，这里改为RandomRange(32,254) ，就好了
buffer:=pwd;
pwd_str:=char(pwd );
blockwrite(dest_file,buffer,1,byteswritten);
end
else
begin
blockread(soure_file,buffer,sizeof(buffer),bytesread);
pwd:=buffer;
end;
totalread:=0;
fsize:=filesize(soure_file);
repeat
blockread(soure_file,buffer,sizeof(buffer),bytesread);
if bytesread>0 then
begin
buffer:=setpasswrod(buffer ,pwd );
blockwrite(dest_file,buffer,bytesread,byteswritten);
if bytesread<>byteswritten then
raise exception.Create('复制文件出错！')
else
begin
totalread:=totalread+bytesread;
end;
end
until bytesread=0;
except
erase(dest_file);
raise;
end;
finally
closefile(dest_file);
closefile(soure_file);
end;
finally
end;
function TForm_pwdfile.setpasswrod(sou_str:variant;pwd_str:variant):variant;
var
result_str:variant;
soure_str,pswd_str:variant;
begin
soure_str:=sou_str;
pswd_str:=pwd_str;
result_str:=soure_str xor pswd_str;
result:=result_str;
end;
附:同事的用C语言进行的对应加密/解密算法。
经我的算法加密后的文件，在他那里发现问题。 到底是我的问题，还是他的问题呢？
int
my_encrypt(file1,file2)
char *file1;
char *file2;
{
FILE *fp,*fp2;
char ch,ch1;
if((fp=fopen(file1,"r"
) == NULL){ return (-1);
}
if((fp2=fopen(file2,"w"
) == NULL){ return (-1);
}
ch = fgetc(fp);
ch1 = fgetc(fp);
while (!feof(fp)) {
ch1 = ch1 ^ ch;
fputc(ch1,fp2);
ch1 = fgetc(fp);
}
fclose(fp);
fclose(fp2);
return 0;
}
int
my_crypt(file1,file2,ch)
char *file1;
char *file2;
char ch;
{
FILE *fp,*fp2;
char ch1;
int i;
if((fp=fopen(file1,"r"
) == NULL){ return (-1);
}
if((fp2=fopen(file2,"w"
) == NULL){ return (-1);
}
fputc(ch,fp2);
ch1 = fgetc(fp);
while (!feof(fp)) {
ch1 = ch1 ^ ch;
fputc(ch1,fp2);
ch1 = fgetc(fp);
}
fclose(fp);
fclose(fp2);
return 0;
}
发分。。