CoAP Secure
API > Add-Ons > CoAP

This module includes functions that control CoAP Secure (CoAP over DTLS) communication.

Macros

#define OT_DEFAULT_COAP_SECURE_PORT 5684
Default CoAP Secure port, as specified in RFC 7252.

Typedefs

typedef void(* otHandleCoapSecureClientConnect ) (bool aConnected, void *aContext)
This function pointer is called when the DTLS connection state changes.

Functions

otError otCoapSecureStart ( otInstance *aInstance, uint16_t aPort)
This function starts the CoAP Secure service.
void otCoapSecureStop ( otInstance *aInstance)
This function stops the CoAP Secure server.
void otCoapSecureSetPsk ( otInstance *aInstance, const uint8_t *aPsk, uint16_t aPskLength, const uint8_t *aPskIdentity, uint16_t aPskIdLength)
This method sets the Pre-Shared Key (PSK) and cipher suite DTLS_PSK_WITH_AES_128_CCM_8.
otError otCoapSecureGetPeerCertificateBase64 ( otInstance *aInstance, unsigned char *aPeerCert, size_t *aCertLength, size_t aCertBufferSize)
This method returns the peer x509 certificate base64 encoded.
void otCoapSecureSetSslAuthMode ( otInstance *aInstance, bool aVerifyPeerCertificate)
This method sets the authentication mode for the coap secure connection.
void otCoapSecureSetCertificate ( otInstance *aInstance, const uint8_t *aX509Cert, uint32_t aX509Length, const uint8_t *aPrivateKey, uint32_t aPrivateKeyLength)
This method sets the local device's X509 certificate with corresponding private key for DTLS session with DTLS_ECDHE_ECDSA_WITH_AES_128_CCM_8.
void otCoapSecureSetCaCertificateChain ( otInstance *aInstance, const uint8_t *aX509CaCertificateChain, uint32_t aX509CaCertChainLength)
This method sets the trusted top level CAs.
otError otCoapSecureConnect ( otInstance *aInstance, const otSockAddr *aSockAddr, otHandleCoapSecureClientConnect aHandler, void *aContext)
This method initializes DTLS session with a peer.
void otCoapSecureDisconnect ( otInstance *aInstance)
This method stops the DTLS connection.
bool otCoapSecureIsConnected ( otInstance *aInstance)
This method indicates whether or not the DTLS session is connected.
bool otCoapSecureIsConnectionActive ( otInstance *aInstance)
This method indicates whether or not the DTLS session is active.
otError otCoapSecureSendRequest ( otInstance *aInstance, otMessage *aMessage, otCoapResponseHandler aHandler, void *aContext)
This method sends a CoAP request over secure DTLS connection.
void otCoapSecureAddResource ( otInstance *aInstance, otCoapResource *aResource)
This function adds a resource to the CoAP Secure server.
void otCoapSecureRemoveResource ( otInstance *aInstance, otCoapResource *aResource)
This function removes a resource from the CoAP Secure server.
void otCoapSecureSetDefaultHandler ( otInstance *aInstance, otCoapRequestHandler aHandler, void *aContext)
This function sets the default handler for unhandled CoAP Secure requests.
void otCoapSecureSetClientConnectedCallback ( otInstance *aInstance, otHandleCoapSecureClientConnect aHandler, void *aContext)
This method sets the connected callback to indicate, when a Client connect to the CoAP Secure server.
otError otCoapSecureSendResponse ( otInstance *aInstance, otMessage *aMessage, const otMessageInfo *aMessageInfo)
This function sends a CoAP response from the CoAP Secure server.

Detailed Description

This module includes functions that control CoAP Secure (CoAP over DTLS) communication.

The functions in this module are available when CoAP Secure API feature ( OPENTHREAD_CONFIG_COAP_SECURE_API_ENABLE ) is enabled.

Typedef Documentation

◆ otHandleCoapSecureClientConnect

typedef void(* otHandleCoapSecureClientConnect) (bool aConnected, void *aContext)

This function pointer is called when the DTLS connection state changes.

Parameters
[in] aConnected true, if a connection was established, false otherwise.
[in] aContext A pointer to arbitrary context information.

Function Documentation

◆ otCoapSecureAddResource()

void otCoapSecureAddResource ( otInstance * aInstance,
otCoapResource * aResource
)

This function adds a resource to the CoAP Secure server.

Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aResource A pointer to the resource.

◆ otCoapSecureConnect()

otError otCoapSecureConnect ( otInstance * aInstance,
const otSockAddr * aSockAddr,
otHandleCoapSecureClientConnect aHandler,
void * aContext
)

This method initializes DTLS session with a peer.

Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aSockAddr A pointer to the remote sockaddr.
[in] aHandler A pointer to a function that will be called when the DTLS connection state changes.
[in] aContext A pointer to arbitrary context information.
Return values
OT_ERROR_NONE Successfully started DTLS connection.

◆ otCoapSecureDisconnect()

void otCoapSecureDisconnect ( otInstance * aInstance )

This method stops the DTLS connection.

Parameters
[in] aInstance A pointer to an OpenThread instance.

◆ otCoapSecureGetPeerCertificateBase64()

otError otCoapSecureGetPeerCertificateBase64 ( otInstance * aInstance,
unsigned char * aPeerCert,
size_t * aCertLength,
size_t aCertBufferSize
)

This method returns the peer x509 certificate base64 encoded.

Note
This function requires the build-time feature MBEDTLS_BASE64_C to be enabled.
Parameters
[in] aInstance A pointer to an OpenThread instance.
[out] aPeerCert A pointer to the base64 encoded certificate buffer.
[out] aCertLength The length of the base64 encoded peer certificate.
[in] aCertBufferSize The buffer size of aPeerCert.
Return values
OT_ERROR_INVALID_STATE Not connected yet.
OT_ERROR_NONE Successfully get the peer certificate.
OT_ERROR_NO_BUFS Can't allocate memory for certificate.

◆ otCoapSecureIsConnected()

bool otCoapSecureIsConnected ( otInstance * aInstance )

This method indicates whether or not the DTLS session is connected.

Parameters
[in] aInstance A pointer to an OpenThread instance.
Return values
TRUE The DTLS session is connected.
FALSE The DTLS session is not connected.

◆ otCoapSecureIsConnectionActive()

bool otCoapSecureIsConnectionActive ( otInstance * aInstance )

This method indicates whether or not the DTLS session is active.

Parameters
[in] aInstance A pointer to an OpenThread instance.
Return values
TRUE If DTLS session is active.
FALSE If DTLS session is not active.

◆ otCoapSecureRemoveResource()

void otCoapSecureRemoveResource ( otInstance * aInstance,
otCoapResource * aResource
)

This function removes a resource from the CoAP Secure server.

Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aResource A pointer to the resource.

◆ otCoapSecureSendRequest()

otError otCoapSecureSendRequest ( otInstance * aInstance,
otMessage * aMessage,
otCoapResponseHandler aHandler,
void * aContext
)

This method sends a CoAP request over secure DTLS connection.

If a response for a request is expected, respective function and context information should be provided. If no response is expected, these arguments should be NULL pointers. If Message Id was not set in the header (equal to 0), this function will assign unique Message Id to the message.

Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aMessage A reference to the message to send.
[in] aHandler A function pointer that shall be called on response reception or time-out.
[in] aContext A pointer to arbitrary context information.
Return values
OT_ERROR_NONE Successfully sent CoAP message.
OT_ERROR_NO_BUFS Failed to allocate retransmission data.
OT_ERROR_INVALID_STATE DTLS connection was not initialized.

◆ otCoapSecureSendResponse()

otError otCoapSecureSendResponse ( otInstance * aInstance,
otMessage * aMessage,
const otMessageInfo * aMessageInfo
)

This function sends a CoAP response from the CoAP Secure server.

Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aMessage A pointer to the CoAP response to send.
[in] aMessageInfo A pointer to the message info associated with aMessage .
Return values
OT_ERROR_NONE Successfully enqueued the CoAP response message.
OT_ERROR_NO_BUFS Insufficient buffers available to send the CoAP response.

◆ otCoapSecureSetCaCertificateChain()

void otCoapSecureSetCaCertificateChain ( otInstance * aInstance,
const uint8_t * aX509CaCertificateChain,
uint32_t aX509CaCertChainLength
)

This method sets the trusted top level CAs.

It is needed for validating the certificate of the peer.

DTLS mode "ECDHE ECDSA with AES 128 CCM 8" for Application CoAPS.

Note
This function requires MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED=1 .
Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aX509CaCertificateChain A pointer to the PEM formatted X509 CA chain.
[in] aX509CaCertChainLength The length of chain.

◆ otCoapSecureSetCertificate()

void otCoapSecureSetCertificate ( otInstance * aInstance,
const uint8_t * aX509Cert,
uint32_t aX509Length,
const uint8_t * aPrivateKey,
uint32_t aPrivateKeyLength
)

This method sets the local device's X509 certificate with corresponding private key for DTLS session with DTLS_ECDHE_ECDSA_WITH_AES_128_CCM_8.

Note
This function requires MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED=1 .
Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aX509Cert A pointer to the PEM formatted X509 certificate.
[in] aX509Length The length of certificate.
[in] aPrivateKey A pointer to the PEM formatted private key.
[in] aPrivateKeyLength The length of the private key.

◆ otCoapSecureSetClientConnectedCallback()

void otCoapSecureSetClientConnectedCallback ( otInstance * aInstance,
otHandleCoapSecureClientConnect aHandler,
void * aContext
)

This method sets the connected callback to indicate, when a Client connect to the CoAP Secure server.

Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aHandler A pointer to a function that will be called once DTLS connection is established.
[in] aContext A pointer to arbitrary context information. May be NULL if not used.

◆ otCoapSecureSetDefaultHandler()

void otCoapSecureSetDefaultHandler ( otInstance * aInstance,
otCoapRequestHandler aHandler,
void * aContext
)

This function sets the default handler for unhandled CoAP Secure requests.

Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aHandler A function pointer that shall be called when an unhandled request arrives.
[in] aContext A pointer to arbitrary context information. May be NULL if not used.

◆ otCoapSecureSetPsk()

void otCoapSecureSetPsk ( otInstance * aInstance,
const uint8_t * aPsk,
uint16_t aPskLength,
const uint8_t * aPskIdentity,
uint16_t aPskIdLength
)

This method sets the Pre-Shared Key (PSK) and cipher suite DTLS_PSK_WITH_AES_128_CCM_8.

Note
This function requires the build-time feature MBEDTLS_KEY_EXCHANGE_PSK_ENABLED to be enabled.
Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aPsk A pointer to the PSK.
[in] aPskLength The PSK length.
[in] aPskIdentity The Identity Name for the PSK.
[in] aPskIdLength The PSK Identity Length.

◆ otCoapSecureSetSslAuthMode()

void otCoapSecureSetSslAuthMode ( otInstance * aInstance,
bool aVerifyPeerCertificate
)

This method sets the authentication mode for the coap secure connection.

Disable or enable the verification of peer certificate. Must be called before start.

Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aVerifyPeerCertificate true, to verify the peer certificate.

◆ otCoapSecureStart()

otError otCoapSecureStart ( otInstance * aInstance,
uint16_t aPort
)

This function starts the CoAP Secure service.

Parameters
[in] aInstance A pointer to an OpenThread instance.
[in] aPort The local UDP port to bind to.
Return values
OT_ERROR_NONE Successfully started the CoAP Secure server.

◆ otCoapSecureStop()

void otCoapSecureStop ( otInstance * aInstance )

This function stops the CoAP Secure server.

Parameters
[in] aInstance A pointer to an OpenThread instance.