Espressif ESP32-S2 User Manual

Chapter 2. API Reference
int keep_alive_interval
Keep-alive interval time (second)
int keep_alive_count
Keep-alive packet retry send count
struct esp_tls_cfg
ESP-TLS configuration parameters.
Note Note about format of certificates:
• This structure includes certificates of a Certificate Authority, of client or server as well as private
keys, which may be of PEM or DER format. In case of PEM format, the buffer must be NULL
terminated (with NULL character included in certificate size).
• Certificate Authority’s certificate may be a chain of certificates in case of PEM format, but could
be only one certificate in case of DER format
• Variables names of certificates and private key buffers and sizes are defined as unions providing
backward compatibility for legacy *_pem_buf and *_pem_bytes names which suggested only PEM
format was supported. It is encouraged to use generic names such as cacert_buf and cacert_bytes.
Public Members
const char **alpn_protos
Application protocols required for HTTP2. If HTTP2/ALPN support is required, a list of protocols that
should be negotiated. The format is length followed by protocol name. For the most common cases the
following is ok: const char **alpn_protos = { “h2”, NULL };
• where ‘h2’is the protocol name
const unsigned char *cacert_buf
Certificate Authority’s certificate in a buffer. Format may be PEM or DER, depending on mbedtls-
support This buffer should be NULL terminated in case of PEM
const unsigned char *cacert_pem_buf
CA certificate buffer legacy name
unsigned int cacert_bytes
Size of Certificate Authority certificate pointed to by cacert_buf (including NULL-terminator in case of
PEM format)
unsigned int cacert_pem_bytes
Size of Certificate Authority certificate legacy name
const unsigned char *clientcert_buf
Client certificate in a buffer Format may be PEM or DER, depending on mbedtls-support This buffer
should be NULL terminated in case of PEM
const unsigned char *clientcert_pem_buf
Client certificate legacy name
unsigned int clientcert_bytes
Size of client certificate pointed to by clientcert_pem_buf (including NULL-terminator in case of PEM
format)
unsigned int clientcert_pem_bytes
Size of client certificate legacy name
const unsigned char *clientkey_buf
Client key in a buffer Format may be PEM or DER, depending on mbedtls-support This buffer should be
NULL terminated in case of PEM
const unsigned char *clientkey_pem_buf
Client key legacy name
unsigned int clientkey_bytes
Size of client key pointed to by clientkey_pem_buf (including NULL-terminator in case of PEM format)
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Release v4.4

Espressif ESP32-S2 Specifications

General

Brand	Espressif
Model	ESP32-S2
Category	Single board computers
Language	English