User Guide

Hash 645
Hash
Description
Converts a variable-length string to a fixed-length string that can act as a “fingerprint” or unique
identifier for the original string. It is not possible to convert the hash result back to the source
string.
Returns
A string.
Category
Conversion functions, Security functions, String functions
Function syntax
Hash(string[, algorithm[, encoding]] )
History
ColdFusion MX 7: Added the algorithm and encoding parameters.
Parameters
Parameter Description
string String to hash.
algorithm (Optional) The algorithm to use to hash the string. ColdFusion MX installs a
cryptography library with the following algorithms:
• CFMX_COMPAT: Generates a hash string identical to that generated by
ColdFusion MX and ColdFusion MX 6.1 (default).
• MD5: (Default) Generates a 32-character, hexadecimal string, using the MD5
algorithm (The algorithm used in ColdFusion MX and prior releases).
• SHA: Generates a 28-character string using the Secure Hash Standard SHA-1
algorithm specified by Nation Institute of Standards and Technology (NIST)
FIPS-180-2.
• SHA-256: Generates a 44-character string using the SHA-256 algorithm
specified by FIPS-180-2.
• SHA-384: Generates a 64-character string using the SHA-384 algorithm
specified by FIPS-180-2.
• SHA-512: Generates an 88-character string using the SHA-1 algorithm specified
by FIPS-180-2.
If you install a security provider with additional cryptography algorithms, you can
also specify any of its hashing algorithms.
encoding (Optional; to use this attribute you must also specify the algorithm parameter) A
string specifying the encoding to use when converting the string to byte data used
by the hash algorithm. Must be a character encoding name recognized by the Java
runtime. The default value is the value specified by the defaultCharset entry in the
neo-runtime.xml file, which is normally UTF-8. Ignored when using the
CFMX_COMPAT algorithm.