coap_tls_is_supported(3)

1COAP_TLS_LIBRARY(3)             libcoap Manual             COAP_TLS_LIBRARY(3)
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NAME

6       coap_tls_library, coap_dtls_is_supported, coap_tls_is_supported,
7       coap_get_tls_library_version, coap_string_tls_version,
8       coap_show_tls_version - Work with CoAP contexts
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SYNOPSIS

11       #include <coap2/coap.h>
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13       int coap_dtls_is_supported(void);
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15       int coap_tls_is_supported(void);
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17       coap_tls_version_t *coap_get_tls_library_version(void);
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19       *char *coap_string_tls_version(char *buffer, size_t bufsize);
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21       void coap_show_tls_version(coap_log_t level);
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23       Link with -lcoap-2, -lcoap-2-gnutls, -lcoap-2-openssl or
24       -lcoap-2-tinydtls depending on your (D)TLS library type.
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DESCRIPTION

27       When the libcoap library was built, it will have been compiled using a
28       specific TLS implementation type (e.g. OpenSSL, GnuTLS, TinyDTLS or
29       noTLS). When the libcoap library is linked into an application, it is
30       possible that the application needs to dynamically determine whether
31       DTLS or TLS is supported, what type of TLS implementation libcoap was
32       compiled with, as well as detect what is the version of the currently
33       loaded TLS library is.
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35       NOTE: If OpenSSL is being used, then the minimum OpenSSL library
36       version is 1.1.0.
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38       NOTE: If GnuTLS is being used, then the minimum GnuTLS library version
39       is 3.3.0.
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41       NOTE: If GnuTLS is going to interoperate with TinyDTLS, then a minimum
42       revision of GnuTLS 3.5.5 which supports CCM algorithms is required by
43       TinyDTLS as TinyDTLS currently only supports CCM.
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45       Network traffic can be encrypted or un-encrypted with libcoap - how to
46       set this up is described in coap_context(3).
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48       Due to the nature of TLS, there can be Callbacks that are invoked as
49       the TLS session negotiates encryption algorithms, encryption keys etc.
50       Where possible, by default, the CoAP layer handles all this
51       automatically. However, there is the flexibility of the Callbacks for
52       imposing additional security checks etc. when PKI is being used. These
53       callbacks need to need to match the TLS implementation type.
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55       The coap_dtls_is_supported() function returns 1 if support for DTLS is
56       enabled, otherwise 0;
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58       The coap_tls_is_supported() function returns 1 if support for TLS is
59       enabled, otherwise 0;
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61       The coap_get_tls_library_version() function returns the TLS
62       implementation type and library version in a coap_tls_version_t*
63       structure.
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65       The coap_string_tls_version() function is used to update the provided
66       buffer with information about the current (D)TLS library that libcoap
67       was built against, as well as the current linked version of the (D)TLS
68       library. buffer defines the buffer to provide the information and
69       bufsize is the size of buffer.
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71       The coap_show_tls_version() function is used log information about the
72       current (D)TLS library that libcoap was built against, as well as the
73       current linked version of the (D)TLS library. level defines the minimum
74       logging level for this information to be output using coap_log().
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76           typedef enum coap_tls_library_t {
77             COAP_TLS_LIBRARY_NOTLS = 0, /**< No DTLS library */
78             COAP_TLS_LIBRARY_TINYDTLS,  /**< Using TinyDTLS library */
79             COAP_TLS_LIBRARY_OPENSSL,   /**< Using OpenSSL library */
80             COAP_TLS_LIBRARY_GNUTLS,    /**< Using GnuTLS library */
81           } coap_tls_library_t;
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83           typedef struct coap_tls_version_t {
84             uint64_t version; /* (D)TLS runtime Library Version */
85             coap_tls_library_t type; /**< Library type. One of COAP_TLS_LIBRARY_* */
86             uint64_t built_version; /* (D)TLS Built against Library Version */
87           }
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RETURN VALUES

90       coap_dtls_is_supported() and coap_tls_is_supported() functions return 0
91       if there is no support, 1 if support is available.
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93       coap_get_tls_library_version() function returns the TLS implementation
94       type and library version in a coap_tls_version_t* structure.
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96       coap_string_tls_version() function returns a pointer to the provided
97       buffer.
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FURTHER INFORMATION

103       See "RFC7252: The Constrained Application Protocol (CoAP)" for further
104       information.
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BUGS

107       Please report bugs on the mailing list for libcoap:
108       libcoap-developers@lists.sourceforge.net
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AUTHORS

111       The libcoap project <libcoap-developers@lists.sourceforge.net>
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115coap_tls_library 4.2.1            07/28/2020               COAP_TLS_LIBRARY(3)