=pod =head1 NAME X509_verify_cert - discover and verify X509 certificte chain =head1 SYNOPSIS #include <openssl/x509.h> int X509_verify_cert(X509_STORE_CTX *ctx); =head1 DESCRIPTION The X509_verify_cert() function attempts to discover and validate a certificate chain based on parameters in B<ctx>. A complete description of the process is contained in the L<verify(1)|verify(1)> manual page. =head1 RETURN VALUES If a complete chain can be built and validated this function returns 1, otherwise it return zero, in exceptional circumstances it can also return a negative code. If the function fails additional error information can be obtained by examining B<ctx> using, for example X509_STORE_CTX_get_error(). =head1 NOTES Applications rarely call this function directly but it is used by OpenSSL internally for certificate validation, in both the S/MIME and SSL/TLS code. The negative return value from X509_verify_cert() can only occur if no certificate is set in B<ctx> (due to a programming error) or if a retry operation is requested during internal lookups (which never happens with standard lookup methods). It is however recommended that application check for <= 0 return value on error. =head1 BUGS This function uses the header B<x509.h> as opposed to most chain verification functiosn which use B<x509_vfy.h>. =head1 SEE ALSO L<X509_STORE_CTX_get_error(3)|X509_STORE_CTX_get_error(3)> =head1 HISTORY X509_verify_cert() is available in all versions of SSLeay and OpenSSL. =cut