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