Transferred crypto module documentation.

docs/en/modules/crypto.md

@@ -0,0 +1,109 @@
+# crypto Module
+
+The crypto modules provides various functions for working with cryptographic algorithms.
+
+## crypto.hash()
+
+Compute a cryptographic hash of a Lua string.
+
+####Syntax
+`hash = crypto.hash(algo, str)`
+
+####Parameters
+  - `algo`: The hash algorithm to use, case insensitive string
+
+Supported hash algorithms are:
+  - MD2 (not available by default, has to be explicitly enabled in user_config.h)
+  - MD5
+  - SHA1
+  - SHA256, SHA384, SHA512 (unless disabled in user_config.h)
+
+####Returns
+A binary string containing the message digest. To obtain the textual version (ASCII hex characters), please use `crypto.toHex()`.
+
+####Example
+```lua
+print(crypto.toHex(crypto.hash("sha1","abc")))
+```
+___
+## crypto.hmac()
+
+Compute a HMAC (Hashed Message Authentication Code) signature for a Lua string.
+
+## Syntax
+`signature = crypto.hmac(algo, str, key)`
+
+####Parameters
+  - algo: hash algorithm to use, case insensitive string
+  - str: data to calculate the hash for
+  - key: key to use for signing, may be a binary string
+
+Supported hash algorithms are:
+  - MD2 (not available by default, has to be explicitly enabled in user_config.h)
+  - MD5
+  - SHA1
+  - SHA256, SHA384, SHA512 (unless disabled in user_config.h)
+
+####Returns
+A binary string containing the HMAC signature. Use `crypto.toHex()` to obtain the textual version.
+
+####Example
+```lua
+print(crypto.toHex(crypto.hmac("sha1","abc","mysecret")))
+```
+___
+## crypto.mask()
+
+Applies an XOR mask to a Lua string. Note that this is not a proper cryptographic mechanism, but some protocols may use it nevertheless.
+
+####Syntax
+masked = crypto.mask (message, mask)
+
+####Parameters
+  - message: message to mask
+  - mask = the mask to apply, repeated if shorter than the message
+
+####Returns
+The masked message, as a binary string. Use `crypto.toHex()` to get a textual representation of it.
+
+####Example
+```lua
+print(crypto.toHex(crypto.mask("some message to obscure","X0Y7")))
+```
+___
+## crypto.toHex()
+
+Provides an ASCII hex representation of a (binary) Lua string. Each byte in the input string is represented as two hex characters in the output.
+
+####Syntax
+`hexstr = crypto.toHex(binary)`
+
+####Parameters
+  - `binary`: input string to get hex representation for
+
+####Returns
+An ASCII hex string.
+
+####Example
+```lua
+print(crypto.toHex(crypto.hash("sha1","abc")))
+```
+___
+## crypto.toBase64()
+
+Provides a Base64 representation of a (binary) Lua string.
+
+####Syntax
+`b64 = crypto.toBase64(binary)`
+
+####Parameters
+  - `binary`: input string to Base64 encode
+
+####Return
+A Base64 encoded string.
+
+####Example
+```lua
+print(crypto.toBase64(crypto.hash("sha1","abc")))
+```
+___

mkdocs.yml

@@ -30,6 +30,7 @@ pages:
     - Support: 'en/support.md'
     - Modules:
         - 'adc': 'en/modules/adc.md'
+        - 'crypto': 'en/modules/crypto.md'
         - 'node': 'en/modules/node.md'
         - 'file': 'en/modules/file.md'
         - 'rtcmem': 'en/modules/rtcmem.md'