1---
2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
3SPDX-License-Identifier: curl
4Title: CURLOPT_PROXY_ISSUERCERT_BLOB
5Section: 3
6Source: libcurl
7See-also:
8  - CURLOPT_ISSUERCERT_BLOB (3)
9  - CURLOPT_PROXY_SSL_VERIFYHOST (3)
10  - CURLOPT_PROXY_SSL_VERIFYPEER (3)
11  - CURLOPT_SSL_VERIFYHOST (3)
12  - CURLOPT_SSL_VERIFYPEER (3)
13Protocol:
14  - TLS
15TLS-backend:
16  - OpenSSL
17Added-in: 7.71.0
18---
19
20# NAME
21
22CURLOPT_PROXY_ISSUERCERT_BLOB - proxy issuer SSL certificate from memory blob
23
24# SYNOPSIS
25
26~~~c
27#include <curl/curl.h>
28
29CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_ISSUERCERT_BLOB,
30                          struct curl_blob *blob);
31~~~
32
33# DESCRIPTION
34
35Pass a pointer to a curl_blob struct, which contains information (pointer and
36size) about a memory block with binary data of a CA certificate in PEM
37format. If the option is set, an additional check against the peer certificate
38is performed to verify the issuer of the HTTPS proxy is indeed the one
39associated with the certificate provided by the option. This additional check
40is useful in multi-level PKI where one needs to enforce that the peer
41certificate is from a specific branch of the tree.
42
43This option should be used in combination with the
44CURLOPT_PROXY_SSL_VERIFYPEER(3) option. Otherwise, the result of the
45check is not considered as failure.
46
47A specific error code (CURLE_SSL_ISSUER_ERROR) is defined with the option,
48which is returned if the setup of the SSL/TLS session has failed due to a
49mismatch with the issuer of peer certificate
50(CURLOPT_PROXY_SSL_VERIFYPEER(3) has to be set too for the check to fail).
51
52If the blob is initialized with the flags member of struct curl_blob set to
53CURL_BLOB_COPY, the application does not have to keep the buffer around after
54setting this.
55
56This option is an alternative to CURLOPT_PROXY_ISSUERCERT(3) which
57instead expects a filename as input.
58
59# DEFAULT
60
61NULL
62
63# %PROTOCOLS%
64
65# EXAMPLE
66
67~~~c
68
69extern char *certificateData; /* point to the data */
70size_t filesize; /* size of the data */
71
72int main(void)
73{
74  CURL *curl = curl_easy_init();
75  if(curl) {
76    CURLcode res;
77    struct curl_blob blob;
78    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
79    /* using an HTTPS proxy */
80    curl_easy_setopt(curl, CURLOPT_PROXY, "https://localhost:443");
81    blob.data = certificateData;
82    blob.len = filesize;
83    blob.flags = CURL_BLOB_COPY;
84    curl_easy_setopt(curl, CURLOPT_PROXY_ISSUERCERT_BLOB, &blob);
85    res = curl_easy_perform(curl);
86    curl_easy_cleanup(curl);
87  }
88}
89~~~
90
91# %AVAILABILITY%
92
93# RETURN VALUE
94
95Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or
96CURLE_OUT_OF_MEMORY if there was insufficient heap space.
97