NAME

       X509_verify_cert - discover and verify X509 certificte chain

SYNOPSIS

        #include <openssl/x509.h>

        int X509_verify_cert(X509_STORE_CTX *ctx);

DESCRIPTION

       The X509_verify_cert() function attempts to discover and validate a certificate chain
       based on parameters in ctx. A complete description of the process is contained in the
       verify(1) manual page.

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 ctx using,
       for example X509_STORE_CTX_get_error().

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 ctx (due to a programming error); if X509_verify_cert() twice without reinitialising
       ctx in between; 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.

BUGS

       This function uses the header x509.h as opposed to most chain verification functiosn which
       use x509_vfy.h.

SEE ALSO

       X509_STORE_CTX_get_error(3)

HISTORY

       X509_verify_cert() is available in all versions of SSLeay and OpenSSL.