curl/SOURCES/0027-curl-7.61.1-CVE-2020-8...

130 lines
3.9 KiB
Diff

From 2470bc91f62cc9b0ab1deac60a67f87b7cc95f6e Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Wed, 2 Dec 2020 23:01:11 +0100
Subject: [PATCH] openssl: make the OCSP verification verify the certificate id
CVE-2020-8286
Reported by anonymous
Bug: https://curl.se/docs/CVE-2020-8286.html
Upstream-commit: d9d01672785b8ac04aab1abb6de95fe3072ae199
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
lib/vtls/openssl.c | 83 ++++++++++++++++++++++++++++++----------------
1 file changed, 54 insertions(+), 29 deletions(-)
diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index 9476773..35cd652 100644
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -1659,6 +1659,11 @@ static CURLcode verifystatus(struct connectdata *conn,
OCSP_BASICRESP *br = NULL;
X509_STORE *st = NULL;
STACK_OF(X509) *ch = NULL;
+ X509 *cert;
+ OCSP_CERTID *id = NULL;
+ int cert_status, crl_reason;
+ ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
+ int ret;
long len = SSL_get_tlsext_status_ocsp_resp(BACKEND->handle, &p);
@@ -1727,43 +1732,63 @@ static CURLcode verifystatus(struct connectdata *conn,
goto end;
}
- for(i = 0; i < OCSP_resp_count(br); i++) {
- int cert_status, crl_reason;
- OCSP_SINGLERESP *single = NULL;
-
- ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
+ /* Compute the certificate's ID */
+ cert = SSL_get_peer_certificate(BACKEND->handle);
+ if(!cert) {
+ failf(data, "Error getting peer certficate");
+ result = CURLE_SSL_INVALIDCERTSTATUS;
+ goto end;
+ }
- single = OCSP_resp_get0(br, i);
- if(!single)
- continue;
+ for(i = 0; i < sk_X509_num(ch); i++) {
+ X509 *issuer = sk_X509_value(ch, i);
+ if(X509_check_issued(issuer, cert) == X509_V_OK) {
+ id = OCSP_cert_to_id(EVP_sha1(), cert, issuer);
+ break;
+ }
+ }
+ X509_free(cert);
- cert_status = OCSP_single_get0_status(single, &crl_reason, &rev,
- &thisupd, &nextupd);
+ if(!id) {
+ failf(data, "Error computing OCSP ID");
+ result = CURLE_SSL_INVALIDCERTSTATUS;
+ goto end;
+ }
- if(!OCSP_check_validity(thisupd, nextupd, 300L, -1L)) {
- failf(data, "OCSP response has expired");
- result = CURLE_SSL_INVALIDCERTSTATUS;
- goto end;
- }
+ /* Find the single OCSP response corresponding to the certificate ID */
+ ret = OCSP_resp_find_status(br, id, &cert_status, &crl_reason, &rev,
+ &thisupd, &nextupd);
+ OCSP_CERTID_free(id);
+ if(ret != 1) {
+ failf(data, "Could not find certificate ID in OCSP response");
+ result = CURLE_SSL_INVALIDCERTSTATUS;
+ goto end;
+ }
- infof(data, "SSL certificate status: %s (%d)\n",
- OCSP_cert_status_str(cert_status), cert_status);
+ /* Validate the corresponding single OCSP response */
+ if(!OCSP_check_validity(thisupd, nextupd, 300L, -1L)) {
+ failf(data, "OCSP response has expired");
+ result = CURLE_SSL_INVALIDCERTSTATUS;
+ goto end;
+ }
- switch(cert_status) {
- case V_OCSP_CERTSTATUS_GOOD:
- break;
+ infof(data, "SSL certificate status: %s (%d)\n",
+ OCSP_cert_status_str(cert_status), cert_status);
- case V_OCSP_CERTSTATUS_REVOKED:
- result = CURLE_SSL_INVALIDCERTSTATUS;
+ switch(cert_status) {
+ case V_OCSP_CERTSTATUS_GOOD:
+ break;
- failf(data, "SSL certificate revocation reason: %s (%d)",
- OCSP_crl_reason_str(crl_reason), crl_reason);
- goto end;
+ case V_OCSP_CERTSTATUS_REVOKED:
+ result = CURLE_SSL_INVALIDCERTSTATUS;
+ failf(data, "SSL certificate revocation reason: %s (%d)",
+ OCSP_crl_reason_str(crl_reason), crl_reason);
+ goto end;
- case V_OCSP_CERTSTATUS_UNKNOWN:
- result = CURLE_SSL_INVALIDCERTSTATUS;
- goto end;
- }
+ case V_OCSP_CERTSTATUS_UNKNOWN:
+ default:
+ result = CURLE_SSL_INVALIDCERTSTATUS;
+ goto end;
}
end:
--
2.26.2