Generate digest
Generate digest ( param ; algorithm {; *} ) -> Function result
| Parameter | Type | Description | |
|---|---|---|---|
| param | BLOB, Text variable | 🡒 | Blob or text for which to get digest key |
| algorithm | Longint | 🡒 | Algorithm used to return key: 0 = MD5 Digest, 1 = SHA1 Digest, 2 = 4D digest, 3 = SHA-256 digest, 4 = SHA-512 digest |
| * | Operator | 🡒 | Encode digest in Base64URL |
| Function result | Text | 🡐 | Value of digest key |
Description
The Generate digest command returns the digest key of a BLOB or text after application of an encryption algorithm.
Pass a Text or BLOB field or variable in the param parameter. The Generate digest function returns the digest key as a string.
In the algorithm parameter, pass a value designating which hash function to use. Use one of the following constants, found in the Digest Type theme:
| Constant | Value | Comment |
|---|---|---|
| _o_4D REST digest | 2 | *** Obsolete constant *** |
| MD5 digest | 0 | Message Digest 5 algorithm. A series of 128 bits returned as a string of 32 hexadecimal characters. |
| SHA1 digest | 1 | Secure Hash 1 algorithm. A series of 160 bits returned as a string of 40 hexadecimal characters. |
| SHA256 digest | 3 | (SHA-2 family) SHA-256 is a series of 256 bits returned as a string of 64 hexadecimal characters. |
| SHA512 digest | 4 | (SHA-2 family) SHA-512 is a series of 512 bits returned as a string of 128 hexadecimal characters. |
Note: It is not recommended to use MD5 and SHA algorithms to handle passwords; if you need to check passwords, you are advised to use Generate password hash and Verify password hash commands.
By default if the * parameter is omitted, the returned digest is encoded in hexadecimal. Pass the * parameter if you want it to be encoded in Base64URL.
The value returned for the same object is the same on all the platforms (macOS/Windows). The calculation is performed based on the representation in UTF-8 of the text passed in the parameter.
Note: If you use the command with an empty text/BLOB, it does not return void but a string value (for example "d41d8cd98f00b204e9800998ecf8427e" for MD5).
Example 1
This example compares two images using the MD5 algorithm:
var $vPict1;$vPict2 : Picture
var $FirstBlob;$SecondBlob : Blob
READ PICTURE FILE("c:\\myPhotos\\photo1.png")
If(OK=1)
READ PICTURE FILE("c:\\myPhotos\\photo2.png")
If(OK=1)
PICTURE TO BLOB($vPict1;$FirstBlob;".png")
PICTURE TO BLOB($vPict2;$SecondBlob;".png")
$MD5_1:=Generate digest($FirstBlob;MD5 digest)
$MD5_2:=Generate digest($SecondBlob;MD5 digest)
If($MD5_1#$MD5_2)
ALERT("These two images are different.")
Else
ALERT("These two images are identical.")
End if
End if
End if
Example 2
These examples illustrate how to retrieve the digest key of a text:
$key1:=Generate digest("The quick brown fox jumps over the lazy dog.";MD5 digest)
// $key1 is "e4d909c290d0fb1ca068ffaddf22cbd0"
$key2:=Generate digest("The quick brown fox jumps over the lazy dog.";SHA1 digest)
// $key2 is "408d94384216f890ff7a0c3528e8bed1e0b01621"
See also
BASE64 DECODE
BASE64 ENCODE
Generate password hash
Secured Protocol
WEB Validate digest