CURLOPT_SSL_CTX_DATA(3)

1CURLOPT_SSL_CTX_DATA(3)    curl_easy_setopt options    CURLOPT_SSL_CTX_DATA(3)
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NAME

6       CURLOPT_SSL_CTX_DATA - custom pointer passed to ssl_ctx callback
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SYNOPSIS

9       #include <curl/curl.h>
10
11       CURLcode   curl_easy_setopt(CURL  *handle,  CURLOPT_SSL_CTX_DATA,  void
12       *pointer);
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DESCRIPTION

15       Data pointer to pass to the ssl context callback set by the option CUR‐
16       LOPT_SSL_CTX_FUNCTION(3),  this  is  the  pointer  you'll  get as third
17       parameter.
18

DEFAULT

20       NULL
21

PROTOCOLS

23       All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
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EXAMPLE

26       /* OpenSSL specific */
27
28       #include <openssl/ssl.h>
29       #include <curl/curl.h>
30       #include <stdio.h>
31
32       static CURLcode sslctx_function(CURL *curl, void *sslctx, void *parm)
33       {
34         X509_STORE *store;
35         X509 *cert=NULL;
36         BIO *bio;
37         char *mypem = (char *)parm;
38         /* get a BIO */
39         bio=BIO_new_mem_buf(mypem, -1);
40         /* use it to read the PEM formatted certificate from memory into an
41          * X509 structure that SSL can use
42          */
43         PEM_read_bio_X509(bio, &cert, 0, NULL);
44         if(cert == NULL)
45           printf("PEM_read_bio_X509 failed...\n");
46
47         /* get a pointer to the X509 certificate store (which may be empty) */
48         store=SSL_CTX_get_cert_store((SSL_CTX *)sslctx);
49
50         /* add our certificate to this store */
51         if(X509_STORE_add_cert(store, cert)==0)
52           printf("error adding certificate\n");
53
54         /* decrease reference counts */
55         X509_free(cert);
56         BIO_free(bio);
57
58         /* all set to go */
59         return CURLE_OK;
60       }
61
62       int main(void)
63       {
64         CURL * ch;
65         CURLcode rv;
66         char *mypem = /* example CA cert PEM - shortened */
67           "-----BEGIN CERTIFICATE-----\n"
68           "MIIHPTCCBSWgAwIBAgIBADANBgkqhkiG9w0BAQQFADB5MRAwDgYDVQQKEwdSb290\n"
69           "IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNB\n"
70           "IENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRA\n"
71           "Y2FjZXJ0Lm9yZzAeFw0wMzAzMzAxMjI5NDlaFw0zMzAzMjkxMjI5NDlaMHkxEDAO\n"
72           "GCSNe9FINSkYQKyTYOGWhlC0elnYjyELn8+CkcY7v2vcB5G5l1YjqrZslMZIBjzk\n"
73           "zk6q5PYvCdxTby78dOs6Y5nCpqyJvKeyRKANihDjbPIky/qbn3BHLt4Ui9SyIAmW\n"
74           "omTxJBzcoTWcFbLUvFUufQb1nA5V9FrWk9p2rSVzTMVD\n"
75           "-----END CERTIFICATE-----\n";
76
77         rv=curl_global_init(CURL_GLOBAL_ALL);
78         ch=curl_easy_init();
79         rv=curl_easy_setopt(ch, CURLOPT_SSLCERTTYPE, "PEM");
80         rv=curl_easy_setopt(ch, CURLOPT_SSL_VERIFYPEER, 1L);
81         rv=curl_easy_setopt(ch, CURLOPT_URL, "https://www.example.com/");
82
83         /* Retrieve page using cacerts' certificate -> will succeed
84          * load the certificate by installing a function doing the necessary
85          * "modifications" to the SSL CONTEXT just before link init
86          */
87         rv=curl_easy_setopt(ch, CURLOPT_SSL_CTX_FUNCTION, *sslctx_function);
88         rv=curl_easy_setopt(ch, CURLOPT_SSL_CTX_DATA, mypem);
89         rv=curl_easy_perform(ch);
90         if(rv==CURLE_OK)
91           printf("*** transfer succeeded ***\n");
92         else
93           printf("*** transfer failed ***\n");
94
95         curl_easy_cleanup(ch);
96         curl_global_cleanup();
97         return rv;
98       }
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AVAILABILITY

101       Added in 7.11.0 for OpenSSL. Added in 7.42.0 for wolfSSL/CyaSSL.  Other
102       SSL backends not supported.
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RETURN VALUE

105       CURLE_OK if supported; or an error such as:
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107       CURLE_NOT_BUILT_IN - Not supported by the SSL backend
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109       CURLE_UNKNOWN_OPTION
110