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authorJay Satiro <raysatiro@yahoo.com>2017-12-19 02:17:39 -0500
committerJay Satiro <raysatiro@yahoo.com>2017-12-26 02:08:35 -0500
commita0f3eaf25dd2c4acf1f49d28d5de4f1765521709 (patch)
tree53a2f552a99df162fdd3b917b2a13787f8be1bdb /docs
parent859ac3602159ef3df77ac4cb1ae191b069ff1b5b (diff)
examples/cacertinmem: ignore cert-already-exists error
- Ignore X509_R_CERT_ALREADY_IN_HASH_TABLE errors in the CTX callback since it's possible the cert may have already been loaded by libcurl. - Remove the EXAMPLE code in the CURLOPT_SSL_CTX_FUNCTION.3 doc. Instead have it direct the reader to this cacertinmem.c example. - Fix the CA certificate to use the right CA for example.com, Digicert. Bug: https://curl.haxx.se/mail/lib-2017-12/0057.html Reported-by: Thomas van Hesteren Closes https://github.com/curl/curl/pull/2182
Diffstat (limited to 'docs')
-rw-r--r--docs/examples/cacertinmem.c143
-rw-r--r--docs/libcurl/opts/CURLOPT_SSL_CTX_FUNCTION.374
2 files changed, 92 insertions, 125 deletions
diff --git a/docs/examples/cacertinmem.c b/docs/examples/cacertinmem.c
index 43bb901ac..cf7c76e14 100644
--- a/docs/examples/cacertinmem.c
+++ b/docs/examples/cacertinmem.c
@@ -24,85 +24,103 @@
* </DESC>
*/
+#include <openssl/err.h>
#include <openssl/ssl.h>
#include <curl/curl.h>
#include <stdio.h>
size_t writefunction(void *ptr, size_t size, size_t nmemb, void *stream)
{
- fwrite(ptr, size, nmemb, stream);
+ fwrite(ptr, size, nmemb, (FILE *)stream);
return (nmemb*size);
}
static CURLcode sslctx_function(CURL *curl, void *sslctx, void *parm)
{
- X509_STORE *store;
+ CURLcode rv = CURLE_ABORTED_BY_CALLBACK;
+ X509_STORE *store = NULL;
X509 *cert = NULL;
- BIO *bio;
- char *mypem = /* www.cacert.org */
- "-----BEGIN CERTIFICATE-----\n"\
- "MIIHPTCCBSWgAwIBAgIBADANBgkqhkiG9w0BAQQFADB5MRAwDgYDVQQKEwdSb290\n"\
- "IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNB\n"\
- "IENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRA\n"\
- "Y2FjZXJ0Lm9yZzAeFw0wMzAzMzAxMjI5NDlaFw0zMzAzMjkxMjI5NDlaMHkxEDAO\n"\
- "BgNVBAoTB1Jvb3QgQ0ExHjAcBgNVBAsTFWh0dHA6Ly93d3cuY2FjZXJ0Lm9yZzEi\n"\
- "MCAGA1UEAxMZQ0EgQ2VydCBTaWduaW5nIEF1dGhvcml0eTEhMB8GCSqGSIb3DQEJ\n"\
- "ARYSc3VwcG9ydEBjYWNlcnQub3JnMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIIC\n"\
- "CgKCAgEAziLA4kZ97DYoB1CW8qAzQIxL8TtmPzHlawI229Z89vGIj053NgVBlfkJ\n"\
- "8BLPRoZzYLdufujAWGSuzbCtRRcMY/pnCujW0r8+55jE8Ez64AO7NV1sId6eINm6\n"\
- "zWYyN3L69wj1x81YyY7nDl7qPv4coRQKFWyGhFtkZip6qUtTefWIonvuLwphK42y\n"\
- "fk1WpRPs6tqSnqxEQR5YYGUFZvjARL3LlPdCfgv3ZWiYUQXw8wWRBB0bF4LsyFe7\n"\
- "w2t6iPGwcswlWyCR7BYCEo8y6RcYSNDHBS4CMEK4JZwFaz+qOqfrU0j36NK2B5jc\n"\
- "G8Y0f3/JHIJ6BVgrCFvzOKKrF11myZjXnhCLotLddJr3cQxyYN/Nb5gznZY0dj4k\n"\
- "epKwDpUeb+agRThHqtdB7Uq3EvbXG4OKDy7YCbZZ16oE/9KTfWgu3YtLq1i6L43q\n"\
- "laegw1SJpfvbi1EinbLDvhG+LJGGi5Z4rSDTii8aP8bQUWWHIbEZAWV/RRyH9XzQ\n"\
- "QUxPKZgh/TMfdQwEUfoZd9vUFBzugcMd9Zi3aQaRIt0AUMyBMawSB3s42mhb5ivU\n"\
- "fslfrejrckzzAeVLIL+aplfKkQABi6F1ITe1Yw1nPkZPcCBnzsXWWdsC4PDSy826\n"\
- "YreQQejdIOQpvGQpQsgi3Hia/0PsmBsJUUtaWsJx8cTLc6nloQsCAwEAAaOCAc4w\n"\
- "ggHKMB0GA1UdDgQWBBQWtTIb1Mfz4OaO873SsDrusjkY0TCBowYDVR0jBIGbMIGY\n"\
- "gBQWtTIb1Mfz4OaO873SsDrusjkY0aF9pHsweTEQMA4GA1UEChMHUm9vdCBDQTEe\n"\
- "MBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0\n"\
- "IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2Vy\n"\
- "dC5vcmeCAQAwDwYDVR0TAQH/BAUwAwEB/zAyBgNVHR8EKzApMCegJaAjhiFodHRw\n"\
- "czovL3d3dy5jYWNlcnQub3JnL3Jldm9rZS5jcmwwMAYJYIZIAYb4QgEEBCMWIWh0\n"\
- "dHBzOi8vd3d3LmNhY2VydC5vcmcvcmV2b2tlLmNybDA0BglghkgBhvhCAQgEJxYl\n"\
- "aHR0cDovL3d3dy5jYWNlcnQub3JnL2luZGV4LnBocD9pZD0xMDBWBglghkgBhvhC\n"\
- "AQ0ESRZHVG8gZ2V0IHlvdXIgb3duIGNlcnRpZmljYXRlIGZvciBGUkVFIGhlYWQg\n"\
- "b3ZlciB0byBodHRwOi8vd3d3LmNhY2VydC5vcmcwDQYJKoZIhvcNAQEEBQADggIB\n"\
- "ACjH7pyCArpcgBLKNQodgW+JapnM8mgPf6fhjViVPr3yBsOQWqy1YPaZQwGjiHCc\n"\
- "nWKdpIevZ1gNMDY75q1I08t0AoZxPuIrA2jxNGJARjtT6ij0rPtmlVOKTV39O9lg\n"\
- "18p5aTuxZZKmxoGCXJzN600BiqXfEVWqFcofN8CCmHBh22p8lqOOLlQ+TyGpkO/c\n"\
- "gr/c6EWtTZBzCDyUZbAEmXZ/4rzCahWqlwQ3JNgelE5tDlG+1sSPypZt90Pf6DBl\n"\
- "Jzt7u0NDY8RD97LsaMzhGY4i+5jhe1o+ATc7iwiwovOVThrLm82asduycPAtStvY\n"\
- "sONvRUgzEv/+PDIqVPfE94rwiCPCR/5kenHA0R6mY7AHfqQv0wGP3J8rtsYIqQ+T\n"\
- "SCX8Ev2fQtzzxD72V7DX3WnRBnc0CkvSyqD/HMaMyRa+xMwyN2hzXwj7UfdJUzYF\n"\
- "CpUCTPJ5GhD22Dp1nPMd8aINcGeGG7MW9S/lpOt5hvk9C8JzC6WZrG/8Z7jlLwum\n"\
- "GCSNe9FINSkYQKyTYOGWhlC0elnYjyELn8+CkcY7v2vcB5G5l1YjqrZslMZIBjzk\n"\
- "zk6q5PYvCdxTby78dOs6Y5nCpqyJvKeyRKANihDjbPIky/qbn3BHLt4Ui9SyIAmW\n"\
- "omTxJBzcoTWcFbLUvFUufQb1nA5V9FrWk9p2rSVzTMVD\n"\
+ BIO *bio = NULL;
+ char *mypem =
+ /* CA for example.com. CN = DigiCert High Assurance EV Root CA */
+ "-----BEGIN CERTIFICATE-----\n"
+ "MIIDxTCCAq2gAwIBAgIQAqxcJmoLQJuPC3nyrkYldzANBgkqhkiG9w0BAQUFADBs\n"
+ "MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3\n"
+ "d3cuZGlnaWNlcnQuY29tMSswKQYDVQQDEyJEaWdpQ2VydCBIaWdoIEFzc3VyYW5j\n"
+ "ZSBFViBSb290IENBMB4XDTA2MTExMDAwMDAwMFoXDTMxMTExMDAwMDAwMFowbDEL\n"
+ "MAkGA1UEBhMCVVMxFTATBgNVBAoTDERpZ2lDZXJ0IEluYzEZMBcGA1UECxMQd3d3\n"
+ "LmRpZ2ljZXJ0LmNvbTErMCkGA1UEAxMiRGlnaUNlcnQgSGlnaCBBc3N1cmFuY2Ug\n"
+ "RVYgUm9vdCBDQTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAMbM5XPm\n"
+ "+9S75S0tMqbf5YE/yc0lSbZxKsPVlDRnogocsF9ppkCxxLeyj9CYpKlBWTrT3JTW\n"
+ "PNt0OKRKzE0lgvdKpVMSOO7zSW1xkX5jtqumX8OkhPhPYlG++MXs2ziS4wblCJEM\n"
+ "xChBVfvLWokVfnHoNb9Ncgk9vjo4UFt3MRuNs8ckRZqnrG0AFFoEt7oT61EKmEFB\n"
+ "Ik5lYYeBQVCmeVyJ3hlKV9Uu5l0cUyx+mM0aBhakaHPQNAQTXKFx01p8VdteZOE3\n"
+ "hzBWBOURtCmAEvF5OYiiAhF8J2a3iLd48soKqDirCmTCv2ZdlYTBoSUeh10aUAsg\n"
+ "EsxBu24LUTi4S8sCAwEAAaNjMGEwDgYDVR0PAQH/BAQDAgGGMA8GA1UdEwEB/wQF\n"
+ "MAMBAf8wHQYDVR0OBBYEFLE+w2kD+L9HAdSYJhoIAu9jZCvDMB8GA1UdIwQYMBaA\n"
+ "FLE+w2kD+L9HAdSYJhoIAu9jZCvDMA0GCSqGSIb3DQEBBQUAA4IBAQAcGgaX3Nec\n"
+ "nzyIZgYIVyHbIUf4KmeqvxgydkAQV8GK83rZEWWONfqe/EW1ntlMMUu4kehDLI6z\n"
+ "eM7b41N5cdblIZQB2lWHmiRk9opmzN6cN82oNLFpmyPInngiK3BD41VHMWEZ71jF\n"
+ "hS9OMPagMRYjyOfiZRYzy78aG6A9+MpeizGLYAiJLQwGXFK3xPkKmNEVX58Svnw2\n"
+ "Yzi9RKR/5CYrCsSXaQ3pjOLAEFe4yHYSkVXySGnYvCoCWw9E1CAx2/S6cCZdkGCe\n"
+ "vEsXCS+0yx5DaMkHJ8HSXPfqIbloEpw8nL+e/IBcm2PN7EeqJSdnoDfzAIJ9VNep\n"
+ "+OkuE6N36B9K\n"
"-----END CERTIFICATE-----\n";
+
+ /* clear the current thread's OpenSSL error queue */
+ ERR_clear_error();
+
/* get a BIO */
bio = BIO_new_mem_buf(mypem, -1);
+ if(!bio)
+ goto err;
+
/* use it to read the PEM formatted certificate from memory into an X509
* structure that SSL can use
*/
- PEM_read_bio_X509(bio, &cert, 0, NULL);
- if(cert == NULL)
- printf("PEM_read_bio_X509 failed...\n");
+ if(!PEM_read_bio_X509(bio, &cert, 0, NULL))
+ goto err;
/* get a pointer to the X509 certificate store (which may be empty!) */
store = SSL_CTX_get_cert_store((SSL_CTX *)sslctx);
+ if(!store)
+ goto err;
/* add our certificate to this store */
- if(X509_STORE_add_cert(store, cert) == 0)
- printf("error adding certificate\n");
+ if(!X509_STORE_add_cert(store, cert)) {
+ unsigned long error = ERR_peek_last_error();
+
+ /* Ignore error X509_R_CERT_ALREADY_IN_HASH_TABLE which means the
+ * certificate is already in the store. That could happen if
+ * libcurl already loaded the certificate from a ca cert bundle
+ * set at libcurl build-time or runtime.
+ */
+ if(ERR_GET_LIB(error) != ERR_LIB_X509 ||
+ ERR_GET_REASON(error) != X509_R_CERT_ALREADY_IN_HASH_TABLE)
+ goto err;
+
+ ERR_clear_error();
+ }
+
+ rv = CURLE_OK;
+
+err:
+ if(rv != CURLE_OK) {
+ char errbuf[256];
+ unsigned long error = ERR_peek_last_error();
+
+ fprintf(stderr, "error adding certificate\n");
+ if(error) {
+ ERR_error_string_n(error, errbuf, sizeof errbuf);
+ fprintf(stderr, "%s\n", errbuf);
+ }
+ }
- /* decrease reference counts */
X509_free(cert);
BIO_free(bio);
+ ERR_clear_error();
- /* all set to go */
- return CURLE_OK;
+ return rv;
}
int main(void)
@@ -124,7 +142,15 @@ int main(void)
rv = curl_easy_setopt(ch, CURLOPT_SSL_VERIFYPEER, 1L);
rv = curl_easy_setopt(ch, CURLOPT_URL, "https://www.example.com/");
- /* first try: retrieve page without cacerts' certificate -> will fail
+ /* turn off the default CA locations (optional)
+ * otherwise libcurl will load CA certificates from the locations that
+ * were detected/specified at build-time
+ */
+ rv = curl_easy_setopt(ch, CURLOPT_CAINFO, NULL);
+ rv = curl_easy_setopt(ch, CURLOPT_CAPATH, NULL);
+
+ /* first try: retrieve page without ca certificates -> should fail
+ * unless libcurl was built --with-ca-fallback enabled at build-time
*/
rv = curl_easy_perform(ch);
if(rv == CURLE_OK)
@@ -132,6 +158,17 @@ int main(void)
else
printf("*** transfer failed ***\n");
+ /* use a fresh connection (optional)
+ * this option seriously impacts performance of multiple transfers but
+ * it is necessary order to demonstrate this example. recall that the
+ * ssl ctx callback is only called _before_ an SSL connection is
+ * established, therefore it will not affect existing verified SSL
+ * connections already in the connection cache associated with this
+ * handle. normally you would set the ssl ctx function before making
+ * any transfers, and not use this option.
+ */
+ rv = curl_easy_setopt(ch, CURLOPT_FRESH_CONNECT, 1L);
+
/* second try: retrieve page using cacerts' certificate -> will succeed
* load the certificate by installing a function doing the necessary
* "modifications" to the SSL CONTEXT just before link init
diff --git a/docs/libcurl/opts/CURLOPT_SSL_CTX_FUNCTION.3 b/docs/libcurl/opts/CURLOPT_SSL_CTX_FUNCTION.3
index 6a6c57f35..929e0ee27 100644
--- a/docs/libcurl/opts/CURLOPT_SSL_CTX_FUNCTION.3
+++ b/docs/libcurl/opts/CURLOPT_SSL_CTX_FUNCTION.3
@@ -62,79 +62,9 @@ NULL
.SH PROTOCOLS
All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
.SH EXAMPLE
-.nf
-/* OpenSSL specific */
-
-#include <openssl/ssl.h>
-#include <curl/curl.h>
-#include <stdio.h>
-
-static CURLcode sslctx_function(CURL *curl, void *sslctx, void *parm)
-{
- X509_STORE *store;
- X509 *cert=NULL;
- BIO *bio;
- char *mypem = /* example CA cert PEM - shortened */
- "-----BEGIN CERTIFICATE-----\\n"
- "MIIHPTCCBSWgAwIBAgIBADANBgkqhkiG9w0BAQQFADB5MRAwDgYDVQQKEwdSb290\\n"
- "IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNB\\n"
- "IENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRA\\n"
- "Y2FjZXJ0Lm9yZzAeFw0wMzAzMzAxMjI5NDlaFw0zMzAzMjkxMjI5NDlaMHkxEDAO\\n"
- "GCSNe9FINSkYQKyTYOGWhlC0elnYjyELn8+CkcY7v2vcB5G5l1YjqrZslMZIBjzk\\n"
- "zk6q5PYvCdxTby78dOs6Y5nCpqyJvKeyRKANihDjbPIky/qbn3BHLt4Ui9SyIAmW\\n"
- "omTxJBzcoTWcFbLUvFUufQb1nA5V9FrWk9p2rSVzTMVD\\n"
- "-----END CERTIFICATE-----\\n";
- /* get a BIO */
- bio=BIO_new_mem_buf(mypem, -1);
- /* use it to read the PEM formatted certificate from memory into an
- * X509 structure that SSL can use
- */
- PEM_read_bio_X509(bio, &cert, 0, NULL);
- if(cert == NULL)
- printf("PEM_read_bio_X509 failed...\\n");
-
- /* get a pointer to the X509 certificate store (which may be empty) */
- store=SSL_CTX_get_cert_store((SSL_CTX *)sslctx);
-
- /* add our certificate to this store */
- if(X509_STORE_add_cert(store, cert)==0)
- printf("error adding certificate\\n");
-
- /* decrease reference counts */
- X509_free(cert);
- BIO_free(bio);
-
- /* all set to go */
- return CURLE_OK;
-}
-
-int main(void)
-{
- CURL * ch;
- CURLcode rv;
-
- rv=curl_global_init(CURL_GLOBAL_ALL);
- ch=curl_easy_init();
- rv=curl_easy_setopt(ch, CURLOPT_SSLCERTTYPE, "PEM");
- rv=curl_easy_setopt(ch, CURLOPT_SSL_VERIFYPEER, 1L);
- rv=curl_easy_setopt(ch, CURLOPT_URL, "https://www.example.com/");
-
- /* Retrieve page using cacerts' certificate -> will succeed
- * load the certificate by installing a function doing the necessary
- * "modifications" to the SSL CONTEXT just before link init
- */
- rv=curl_easy_setopt(ch, CURLOPT_SSL_CTX_FUNCTION, *sslctx_function);
- rv=curl_easy_perform(ch);
- if(rv==CURLE_OK)
- printf("*** transfer succeeded ***\\n");
- else
- printf("*** transfer failed ***\\n");
+See cacertinmem.c in docs/examples directory for usage example.
- curl_easy_cleanup(ch);
- curl_global_cleanup();
- return rv;
-}
-.fi
+https://curl.haxx.se/libcurl/c/cacertinmem.html
.SH AVAILABILITY
Added in 7.11.0 for OpenSSL. Added in 7.42.0 for wolfSSL/CyaSSL. Added in
7.54.0 for mbedTLS. Other SSL backends not supported.