# Cryptography

The cryptographic functions are described below.

* [AESDecrypt( str key, buf data ) buf](/stdlib/crypto.md#aesdecrypt-str-key-buf-data-buf)
* [AESEncrypt( str key, buf data ) buf](/stdlib/crypto.md#aesencrypt-str-key-buf-data-buf)
* [Md5( buf | str data ) buf](/stdlib/crypto.md#md-5-buf-or-str-data-buf)
* [RandomBuf( int size ) buf](/stdlib/crypto.md#randombuf-int-size-buf)
* [Sha256( buf | str data ) buf](/stdlib/crypto.md#sha-256-buf-or-str-data-buf)

## Functions

### AESDecrypt( str key, buf data ) buf

The *AESDecrypt* function decrypts the content of the *buf* variable using the *key* encryption key. The encrypted data must be obtained using the *AESEncrypt* function. The function returns a variable of the *buf* type with decrypted data.

```go
buf encrypted = AESDecrypt(`my password`, encrypted)
```

### AESEncrypt( str key, buf data ) buf

The *AESEncrypt* function encrypts the content of a *buf* variable using the AES-256 algorithm. The *key* parameter is an encryption key. The function returns a variable of *buf* type with encrypted data. Use the *AESDecrypt* function to decrypt the data.

```go
buf crypted = AESEncrypt(`my password`, buf(`Test message`))
```

### Md5(buf|str data) buf

The *Md5* function returns MD5 hash of the *buf* or *str* type variable.

### RandomBuf(int size) buf

The *RandomBuf* function returns a variable of the *buf* type that contains a sequence of random bytes of the specified size.

### Sha256(buf|str data) buf

The *Sha256* function returns SHA5 hash of the *buf* or *str* type variable.


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