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OCTET NumberString to ASCII

Hey Experts,
I'm trying to find a way to convert a OCTET NumberString to a ascii string.
I have a OCTET NumberString value called 3230303730373035313434373336.
And the result should be ASCII value = 20070705144736

As you can se it's a date 2007xxxxx

The OCTET value commes from a ASN decoded file. I'm using C#

Thanks,
Jan

ASKER CERTIFIED SOLUTION

Bob Learned

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Fernando Soto

Hi bibobas;

Try this.

String ByteString = "3230303730373035313434373336";
StringBuilder AscOut = new StringBuilder();

for (int idx = 1; idx < ByteString.Length; idx += 2)
{
AscOut.Append(ByteString.Substring(idx, 1));
}
MessageBox.Show(AscOut.ToString());

Fernando

Bob Learned

Nice code, my friend, but you need 2 strings (Substring(idx, 2)) *BIG GRIN*

Bob

Fernando Soto

No no, I am indexing the string by 2 and just reading the second character which is the character needed for the result string. *BIG GRIN*

drichards

If you are doing that operation a lot, I would make a small mod to avoid the creation of all the tiny substrings. Rather than get a substring, just use the characters directly:

public static string NumberOctetStringToAscii(string input)
{
char baseDigit = (char)0x30;
StringBuilder dateStr = new StringBuilder();
for (int ii = 0; ii < input.Length; ii += 2)
{
char c = (char)(((input[ii] - baseDigit) * 16) + (input[ii + 1] - baseDigit));
dateStr.Append(c);
}
return dateStr.ToString();
}

drichards

Or optimized per FernandoSoto's comment:

public static string NumberOctetStringToAscii(string input)
{
char baseDigit = (char)0x30;
StringBuilder dateStr = new StringBuilder();
for (int ii = 0; ii < input.Length; ii += 2)
{
dateStr.Append(input[ii+1]);
}
return dateStr.ToString();
}

bibobas

ASKER

Hey experts,
Thanks for solutions :-)
What if I want to convert a OCTET String to Ascii ??
Thanks,
Jan