Struct MessageIntegrity

pub struct MessageIntegrity;

The MESSAGE-INTEGRITY attribute contains an HMAC-SHA1 RFC2104 of the STUN message. The MESSAGE-INTEGRITY attribute can be present in any STUN message type. Since it uses the SHA-1 hash, the HMAC will be 20 bytes.

The key for the HMAC depends on which credential mechanism is in use. Section 9.1.1 defines the key for the short-term credential mechanism, and Section 9.2.2 defines the key for the long-term credential mechanism. Other credential mechanisms MUST define the key that is used for the HMAC.

The text used as input to HMAC is the STUN message, up to and including the attribute preceding the MESSAGE-INTEGRITY attribute. The Length field of the STUN message header is adjusted to point to the end of the MESSAGE-INTEGRITY attribute. The value of the MESSAGE-INTEGRITY attribute is set to a dummy value.

Once the computation is performed, the value of the MESSAGE-INTEGRITY attribute is filled in, and the value of the length in the STUN header is set to its correct value – the length of the entire message. Similarly, when validating the MESSAGE-INTEGRITY, the Length field in the STUN header must be adjusted to point to the end of the MESSAGE-INTEGRITY attribute prior to calculating the HMAC over the STUN message, up to and including the attribute preceding the MESSAGE-INTEGRITY attribute. Such adjustment is necessary when attributes, such as FINGERPRINT and MESSAGE-INTEGRITY-SHA256, appear after MESSAGE-INTEGRITY. See also RFC5769 for examples of such calculations.

Trait Implementations

impl<'a> Property<'a> for MessageIntegrity

type Error = StunError

type Inner = &'a [u8]

current attribute inner type.

fn kind() -> AttrKind

get current attribute type.

fn into(value: Self::Inner, buf: &mut BytesMut, _: &[u8])

write the current attribute to the buffer.

fn try_from(buf: &'a [u8], _: &'a [u8]) -> Result<Self::Inner, Self::Error>

convert buffer to current attribute.