get dsa signature value in octect string - c#

I am trying to read the octect string value of attribute dsa-signature. I got the field from default naming context properties. But its in byte array, when I try to convert it into a string it give wrong output.
Does anyone knows how to do correct octect converion?
DirectoryEntry entry = new DirectoryEntry("LDAP://DC=cobra,DC=net");
PropertyValueCollection propCol = entry.Properties["dSASignature"];
Console.WriteLine(propCol.PropertyName + " : " + propCol.Value);
System.Text.UTF8Encoding enc = new System.Text.UTF8Encoding();
string str = enc.GetString((System.Byte[])propCol.Value);
Console.WriteLine("value : " + str);
Thanks in advance

But its in byte array, when I try to convert it into a string it give wrong output.
It's a byte array. Just an arbitrary sequence of bytes. It's not UTF-8-encoded text, which is what you're treating it as.
If you want to display the bytes formatted as hex, you can use:
byte[] data = (byte[]) propCol.Value;
string hex = BitConverter.ToString(data);
If you need to transfer it more efficiently but as text, you could use base64... but ideally you should treat it as a byte array for as long as possible, given that fundamentally it's just binary data.

Related

String value system.byte[] while coverting Base64 value to string in c#

I have two LDIF files from where I am reading values and using it for comparsion using c#
One of the attribute: value in LDIF is a base64 value, need to convert it in UTF-8 format
displayName:: Rmlyc3ROYW1lTGFzdE5hbWU=
So I thought of using string -> byte[], but I am not able to use the above displayName value as string
byte[] newbytes = Convert.FromBase64String(displayname);
string displaynamereadable = Encoding.UTF8.GetString(newbytes);
In my C# code, I am doing this to retrieve the values from the ldif file
for(Entry entry ldif.ReadEntry() ) //reads value from ldif for particular user's
{
foreach(Attr attr in entry) //here attr gives attributes of a particular user
{
if(attr.Name.Equals("displayName"))
{
string attVal = attr.Value[0].ToString(); //here the value of String attVal is system.Byte[], so not able to use it in the next line
byte[] newbytes = Convert.FromBase64String(attVal); //here it throws an error mentioned below
string displaynamereadable = Encoding.UTF8.GetString(attVal);
}
}
}
Error:
The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters.
I am trying to user attVal as String so that I can get the encoded UTf-8 value but its throwing an error.
I tried to use BinaryFormatter and MemoryStream as well, it worked but it inserted so many new chars with the original value.
Snapshot of BinaryFormatter:
object obj = attr.Value[0];
byte[] bytes = null;
BinaryFormatter bf = new BinaryFormatter();
using (MemoryStream ms = new MemoryStream())
{
bf.Serialize(ms, obj);
bytes = (ms.ToArray());
}
string d = Encoding.UTF8.GetString(bytes);
So the result after encoding should be: "FirstNameLastName"
But it gives "\u0002 \u004 \u004 ...................FirstNameLastName\v"
Thanks,
Base64 was designed to send binary data through transfer channels that only support plain text, and as a result, Base64 is always ASCII text. So if attr.Value[0] is a byte array, just interpret those bytes as string using ASCII encoding:
String attVal = Encoding.ASCII.GetString(attr.Value[0] as Byte[]);
Byte[] newbytes = Convert.FromBase64String(attVal);
String displaynamereadable = Encoding.UTF8.GetString(newbytes);
Also note, your code above was feeding attVal into that final line rather than newbytes.

"Specified value has invalid Control characters" when converting SHA512 output to string

I am attempting to create an Hash for an API.
my input is something like this:
FBN|Web|3QTC0001|RS1|260214133217|000000131127897656
And my expected output is like :
17361DU87HT56F0O9967E34FDFFDFG7UO334665324308667FDGJKD66F9888766DFKKJJR466634HH6566734JHJH34766734NMBBN463499876554234343432456
I tried the bellow but I keep getting
"Specified value has invalid Control characters. Parameter name: value"
I am actually doing this in a REST service.
public static string GetHash(string text)
{
string hash = "";
SHA512 alg = SHA512.Create();
byte[] result = alg.ComputeHash(Encoding.UTF8.GetBytes(text));
hash = Encoding.UTF8.GetString(result);
return hash;
}
What am I missing?
The problem is Encoding.UTF8.GetString(result) as the data in result is invalid UTF-8 (it's just binary goo!) so trying to convert it to text is invalid - in general, and specifically for this input - which results in the Exception being thrown.
Instead, convert the byte[] to the hex representation of said byte sequence; don't treat it as UTF-8 encoded text.
See the questions How do you convert Byte Array to Hexadecimal String, and vice versa? and How can I convert a hex string to a byte array?, which discuss several different methods of achieving this task.
In order to make this work you need to convert the individual byte elements into a hex representation
var builder = new StringBuilder();
foreach(var b in result) {
builder.AppendFormat("{0:X2}", b);
}
return builder.ToString();
You might want to consider using Base64 encoding (AKA UUEncode):
public static string GetHash(string text)
{
SHA512 alg = SHA512.Create();
byte[] result = alg.ComputeHash(Encoding.UTF8.GetBytes(text));
return Convert.ToBase64String(result);
}
For your example string, the result is
OJgzW5JdC1IMdVfC0dH98J8tIIlbUgkNtZLmOZsjg9H0wRmwd02tT0Bh/uTOw/Zs+sgaImQD3hh0MlzVbqWXZg==
It has an advantage of being more compact than encoding each byte into two characters: three bytes takes four characters with Base64 encoding or six characters the other way.

Encoding strings to and from base-64

I'm trying to encode some strings back and forth from base-64 string and I'm having truble to get the right result.
string text = base64string.... //Here I have a base-64 string.
byte[] encodedByte = System.Text.ASCIIEncoding.ASCII.GetBytes(text);
string base64Encoded = Convert.ToBase64String(encodedByte);
if (text == base64Encoded) //If the new encoded string is equal to its original value
return base64Encoded;
I have tried my ways to do this and I don't seem to get the right result. I have tried both with System.Text.Encoding.Unicode and System.Text.Encoding.UTF8
What could be the problem? Does anyone have a proper solution?
string text = base64string.... //Here I have a base-64 string.
byte[] encodedByte = System.Text.ASCIIEncoding.ASCII.GetBytes(text);
string base64Encoded = Convert.ToBase64String(encodedByte);
You are double encoding the string. You begin with a base64 string, get the bytes, and then encode it again. If you want to compare you will need to begin with the original string.
If text is a base-64 string, then you are doing it backwards:
byte[] raw = Convert.FromBase64String(text); // unpack the base-64 to a blob
string s = Encoding.UTF8.GetString(raw); // assume the blob is UTF-8, and
// decode to a string
which will get you it as a string. Note, though, that this scenario is only useful for representing unicode text in an ascii format. Normally you wouldn't base-64 encode it if the original contents are string.
Convert whatever it is that you need in Base64 into a Byte array then use the FromBase64String and ToBase64String to convert to and from Base64:
Byte[] buffer = Convert.FromBase64String(myBase64String1);
myBase64String2 = Convert.ToBase64String(buffer);
myBase64String1 will be equal to myBase64String2. You will need to use other methods to get your data type into a Byte array and the reverse to get your data type back. I have used this to convert the content of a class into a byte array and then to Base64 string and write the string to the filesystem. Later I read it back into a class instance by reversing the process.
You have the encoding code correctly laid out. To confirm whether the base64-encoded string is correct, you can try decoding it and comparing the decoded contents to the original:
var decodedBytes = Convert.FromBase64String(base64encoded);
var compareText = System.Text.Encoding.ASCII.GetString(decodedText);
if (text == compareText)
{
// carry on...
return base64encoded;
}

Invalid length for a Base-64 char array

I'm getting a "Invalid length for a Base-64 char array." inside of the IF(){...} are variations i have tried to get it to work. it fails in the first line without calling decrypt(...) proving it's not that functions problem. i get the same error inside with the first decrypt(...) call. the last one using the encoding.ascii... will get me inside the function, but then it fails inside the function. I'm getting the proper encrypted info from the database to string SSnum. it's value is: 4+mFeTp3tPF
try
{
string SSnum = dr.GetString(dr.GetOrdinal("Social Security"));
if (isEncrypted)
{
byte[] temp = Convert.FromBase64String(SSnum);
//SSnum = decrypt(Convert.FromBase64String(SSnum), Key, IV);
//SSnum = decrypt(Encoding.ASCII.GetBytes(SSnum), Key, IV);
}
txt_Social_Security.Text = SSnum;
}
catch { txt_Social_Security.Text = ""; }
I've been told to use the Convert.FromBase64String() and not the ASCII method...so why is it failing, how can i fix it?
Base64 data length should be multiple of 4 and with padding char '='
You can change your data as valid base64 data.
string dummyData = imgData.Trim().Replace(" ", "+");
if (dummyData.Length % 4 > 0)
dummyData = dummyData.PadRight(dummyData.Length + 4 - dummyData.Length % 4, '=');
byte[] byteArray = Convert.FromBase64String(dummyData);
https://stackoverflow.com/a/9301545/2024022
This will help you , try once.
Thanks
suribabu.
it's value is: 4+mFeTp3tPF
You are receiving this error because that value, 4+mFeTp3tPF, is in fact not valid Base64.
Is it possible you are simply missing the required padding character, as so 4+mFeTp3tPF=?
Are you certain that you have a Base64 string? Base64 is a means of encoding binary data into a string while only using standard 7-bit ASCII characters. It's not a string encoding like ASCII and has some control bytes present. You have a Base64 string if you're using Convert.ToBase64String to obtain the value (which, if you're trying to store binary data as a string, is your best bet)
Judging by your error (and your example data), I'm assuming that you do not have a Base64 string. If you need to store binary data in the database, you can either create a column using a binary type or encode the string into Base64 by using Convert.ToBase64String.
byte[] inputData = ...;
string base64String = Convert.ToBase64String(inputData);
byte[] outputData = Convert.FromBase64String(base64String);
Here, outputData should contain the same data as inputData.
If what you have is just an ASCII-encoded string, then your original practice of using System.Text.Encoding.ASCII.GetBytes() is correct, but you should change this to use a Base64 string if you can.
Are you sure that string 4+mFeTp3tPF is well-formed Base64 string?
I've tried some online services - no one could convert it.
replace
byte[] temp = Convert.FromBase64String(SSnum);
to this
var temp = UTF8Encoding.UTF8.GetBytes(SSnum);

display arbinary value in label

I want to add the value from my database to a label.
The value has a datatype varbinary(max)
string buF = dt.Rows[i]["BuF"].ToString();
Label3.Text = buF;
For this I get the output as System.Byte[] which is not the correct value.
Any suggestions?
Thanks
This sounds like a job for the BitConverter class:
string buF = BitConverter.ToString((byte[])dt.Rows[i]["BuF"]);
Label3.Text = buF;
Note that this will insert hyphens between each byte value in the output string. If you want to remove the hyphens and/or generate a different string format then you could do something like this, for example:
string buF =
"0x" + BitConverter.ToString((byte[])dt.Rows[i]["BuF"]).Replace("-", "");
Label3.Text = buF;
Is the data some sort of text encoded as binary? Then use the appropiate Encoding GetString(). You must use the same encoding type (ASCII, UTF8, Unicode etc) or build one with the appropiate CodePage for whatever is in that binary field.

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