New chain building flags.

New flags to build certificate chains. The can be used to rearrange
the chain so all an application needs to do is add all certificates
in arbitrary order and then build the chain to check and correct them.

Add verify error code when building chain.

Update docs.
(cherry picked from commit 13dc3ce9ab483cade378bcf3844c92bacd817316)

1 files changed, 17 insertions, 5 deletions

diff --git a/doc/ssl/SSL_CTX_add1_chain_cert.pod b/doc/ssl/SSL_CTX_add1_chain_cert.pod
index 7676a882ea..72234eef59 100644
--- a/doc/ssl/SSL_CTX_add1_chain_cert.pod
+++ b/doc/ssl/SSL_CTX_add1_chain_cert.pod
@@ -52,11 +52,15 @@ SSL_CTX_clear_chain_certs() clears any existing chain associated with the
 current certificate of B<ctx>.  (This is implemented by calling
 SSL_CTX_set0_chain() with B<sk> set to B<NULL>).
 
-SSL_CTX_build_cert_chain() builds the certificate chain for B<ctx> using the
-chain store. Any existing chain certificates are used as untrusted CAs.
+SSL_CTX_build_cert_chain() builds the certificate chain for B<ctx> normally
+this uses the chain store or the verify store if the chain store is not set.
 If the function is successful the built chain will replace any existing chain.
-The B<flags> parameter can be set to B<SSL_BUILD_CHAIN_FLAG_NO_ROOT> to omit
-the root CA from the built chain.
+The B<flags> parameter can be set to B<SSL_BUILD_CHAIN_FLAG_UNTRUSTED> to use
+existing chain certificates as untrusted CAs, B<SSL_BUILD_CHAIN_FLAG_NO_ROOT>
+to omit the root CA from the built chain, B<SSL_BUILD_CHAIN_FLAG_CHECK> to
+use all existing chain certificates only to build the chain (effectively
+sanity checking and rearranging them if necessary), the flag
+B<SSL_BUILD_CHAIN_FLAG_IGNORE_ERROR> ignores any errors during verification.
 
 Each of these functions operates on the I<current> end entity
 (i.e. server or client) certificate. This is the last certificate loaded or
@@ -105,6 +109,10 @@ be used to check application configuration and to ensure any necessary
 subordinate CAs are sent in the correct order. Misconfigured applications
 sending incorrect certificate chains often cause problems with peers.
 
+For example an application can add any set of certificates using
+SSL_CTX_use_certificate_chain_file() then call SSL_CTX_build_cert_chain()
+with the option B<SSL_BUILD_CHAIN_FLAG_CHECK> to check and reorder them.
+
 Calling SSL_CTX_build_cert_chain() or SSL_build_cert_chain() is more
 efficient than the automatic chain building as it is only performed once.
 Automatic chain building is performed on each new session.
@@ -114,7 +122,11 @@ using SSL_CTX_add_extra_chain_cert() will be used.
 
 =head1 RETURN VALUES
 
-All these functions return 1 for success and 0 for failure.
+SSL_set_current_cert() with B<SSL_CERT_SET_SERVER> return 1 for success, 2 if
+no server certificate is used because the ciphersuites is anonymous and 0
+for failure.
+
+All other functions return 1 for success and 0 for failure.
 
 =back