Semiconductor & Computer Engineering
Synopsis
$sha1(plaintext|&binaryvar|filename,[N]) Returns the sha1 hash for the specified data, where N = 0 for plain text (default), 1 for &binary variable, 2 for filename.
Hash is 160-bits, shown as 40 hexadecimal characters.
Parameters
Required: Data
Optional: Integer 0-2, where 0 (default) indicates data is plaintext, 1 indicates a &binary variable, 2 indicates contents of a filename
Properties
None
Example
Echo the SHA1 hash of plain text string abc to the active window:
//echo -a $sha1(abc) or //echo -a $sha1(abc,0)
$sha1 is case-sensitive, so hash of "abc" is different than hash of "ABC"
Echo the SHA1 hash of the zero-length nul string to the active window:
//echo -a $sha1($nul)
Echo the SHA1 hash of the contents of the mIRC program you're running to the active window:
//echo -a $sha1($mircexe,2)
Echo the SHA1 hash of the first 1000 bytes of the mIRC program you're running to the active window:
//bread $qt($mircexe) 0 1000 &snip | echo -a $sha1(&snip,1)
Suggested Uses:
- Quick way to compare if 2 files are identical. (First check should always be comparing file sizes.)
- Quick way to check if a file's contents have changed since stored sha1 hash was made.
- Verify downloaded file hasn't been corrupted, matches the sender's original.
Note that $sha1($mircexe) is the same as the SHA1 hash for the text string of the drive:\path\filename for the mIRC you're running, regardless of file contents.
mIRC v7.x Unicode-encodes plaintext before providing to $sha1, so v7.x and v6.x return different answers for //echo -a $sha1($chr(233))
Error Messages
Note that $sha1 differs from $crc in that it generates error for non-existent files instead of returning hash of $nul string. Also, in absence of specifying index 0-2, $sha1's default is 0 while $crc's default is 2. Also, hex string returned by $sha1 is lowercase while $crc returns uppercase.
* Error accessing file: $sha1
Either file does not exist, or file permissions don't allow the file to be read. i.e. $sha1(non-existent-file,2) or $sha1(c:\hiberfil.sys,2)
* Invalid parameters: $sha1
Either using a zero-length/non-existent binary variable or specifying an N where $int(%N) isn't 0-2.
Both above errors halt execution of the script
Compatibility
Added: mIRC v6.3
Added on: 16 Aug 2007
Note: Unless otherwise stated, this was the date of original functionality.
Further enhancements may have been made in later versions.