# hash

The `hash` statement is used to generate a base-16 or base-64 encoded hash of data stored in a variable or named buffer.

## Syntax

**`hash sha256 [HMAC [b16|b64]`***`key] target|{target}`***`as`***`result`***`[b16|b64]`**

**`hash md5`***`target|{target}`***`as`***`result`***`[b16|b64]`**

## Details

The `hash` statement uses the contents of *target* as its input and places the final result into *result*. The SHA256 and MD5 hash algorithms are supported.

If *target* is surrounded with curly braces like `{this}` then it is taken to be the name of a memory buffer and the contents of the buffer will be used as input. Otherwise, it is treated as the name of the variable, the value of which will be hashed.

By default the resulting hash is base-16 encoded and the result placed into the variable specified by the *result* argument.

{% hint style="warning" %}
*result* is the **name** of the variable to put the output into, and **not** a reference to the contents of that variable. This is why it is not `${result}`
{% endhint %}

If the optional **`HMAC`***`key`* arguments are provided when the hash type is **`sha256`** then the secret in *key* will be used to generate an HMAC-SHA-256 result. The optional **`b64`** or **`b16`** argument following the `HMAC` option indicates that key is base-64 or base-16 encoded. By default, a clear-text key is assumed.

If the optional **`b64`** argument is used (**`base64`** may also be specified) after the *result* variable, then the result will be base-64 encoded.

The optional **`b16`** argument (**`base16`** may also be used) after the *result* variable is provided for completeness, but need not be specified as this is the default encoding to use.

## Example

Running the script:

```
var hash_me = "This is the data to hash"
var my_secret = "This is my secret key"

# SHA256
hash sha256 hash_me as result
print The SHA256 hash of '${hash_me}' in base-16 is:
print ${result}${NEWLINE}

hash sha256 hash_me as result b64
print The SHA256 hash of '${hash_me}' in base-64 is:
print ${result}${NEWLINE}

# HMACSHA256
hash sha256 hmac ${my_secret} hash_me as result
print The HMACSHA256 hash of '${hash_me}' (using '${my_secret}') in base-16 is:
print ${result}${NEWLINE}

hash sha256 hmac ${my_secret} hash_me as result b64
print The HMACSHA256 hash of '${hash_me}' (using '${my_secret}') in base-64 is:
print ${result}${NEWLINE}
```

results in the following output:

```
The SHA256 hash of 'This is the data to hash' in base-16 is:
1702c37675c14d0ea99b7c23ec29c36286d1769a9f65212218d4380534a53a7a

The SHA256 hash of 'This is the data to hash' in base-64 is:
FwLDdnXBTQ6pm3wj7CnDYobRdpqfZSEiGNQ4BTSlOno=

The HMACSHA256 hash of 'This is the data to hash' (using 'This is my secret key') in base-16 is:
cf854e99094ea5c2a88ee0901a305d5f25dfb5a0f0905eec703618080567b4b5

The HMACSHA256 hash of 'This is the data to hash' (using 'This is my secret key') in base-64 is:
z4VOmQlOpcKojuCQGjBdXyXftaDwkF7scDYYCAVntLU=
```