(mozilla-projects-nss-reference-nss-key-functions)=

# NSS Key Functions

:::{container}
This chapter describes two functions used to manipulate private keys and key databases such as
the key3.db database provided with NSS. This was converted from ["Chapter 6: Key
Functions"](https://developer.mozilla.org/en-US/docs/NSS/SSL_functions/sslkey.html).

- {ref}`mozilla_projects_nss_reference`
- [SECKEY_GetDefaultKeyDB](#seckey_getdefaultkeydb)
- [SECKEY_DestroyPrivateKey](#seckey_destroyprivatekey)

```{rubric} SECKEY_GetDefaultKeyDB
```

Returns a handle to the default key database opened by NSS_Init.

Syntax

1. include \<key.h>
2. include \<keyt.h>

SECKEYKeyDBHandle \*SECKEY_GetDefaultKeyDB(void);

Returns The function returns a handle of type SECKEYKeyDBHandle.

Description NSS_Init opens the certificate, key, and security module databases that you specify
for use with NSS. SECKEYKeyDBHandle returns a handle to the key database opened by NSS_Init.

```{rubric} SECKEY_DestroyPrivateKey
```

Destroys a private key structure.

Syntax

1. include \<key.h>
2. include \<keyt.h>

void SECKEY_DestroyPrivateKey(SECKEYPrivateKey \*key);

Parameter This function has the following parameter:

key

A pointer to the private key structure to destroy.

Description Certificate and key structures are shared objects. When an application makes a copy
of a particular certificate or key structure that already exists in memory, SSL makes a shallow
copy--that is, it increments the reference count for that object rather than making a whole new
copy. When you call CERT_DestroyCertificate or SECKEY_DestroyPrivateKey, the function decrements
the reference count and, if the reference count reaches zero as a result, both frees the memory
and sets all the bits to zero. The use of the word "destroy" in function names or in the
description of a function implies reference counting.

Never alter the contents of a certificate or key structure. If you attempt to do so, the change
affects all the shallow copies of that structure and can cause severe problems.
:::