Document additions for X509 chain verification from HEAD

doc/crypto/DSA_get_ex_new_index.pod

@@ -6,7 +6,7 @@ DSA_get_ex_new_index, DSA_set_ex_data, DSA_get_ex_data - add application specifi
 
 =head1 SYNOPSIS
 
- #include <openssl/DSA.h>
+ #include <openssl/dsa.h>
 
  int DSA_get_ex_new_index(long argl, void *argp,
 		CRYPTO_EX_new *new_func,

doc/crypto/X509_STORE_CTX_get_error.pod

@@ -0,0 +1,303 @@
+=pod
+
+=head1 NAME
+
+X509_STORE_CTX_get_error, X509_STORE_CTX_set_error, X509_STORE_CTX_get_error_depth, X509_STORE_CTX_get_current_cert, X509_STORE_CTX_get1_chain, X509_verify_cert_error_string - get or set certificate verification status information
+
+=head1 SYNOPSIS
+
+ #include <openssl/x509.h>
+ #include <openssl/x509_vfy.h>
+
+ int	X509_STORE_CTX_get_error(X509_STORE_CTX *ctx);
+ void	X509_STORE_CTX_set_error(X509_STORE_CTX *ctx,int s);
+ int	X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx);
+ X509 *	X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx);
+
+ STACK_OF(X509) *X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx);
+
+ const char *X509_verify_cert_error_string(long n);
+
+=head1 DESCRIPTION
+
+These functions are typically called after X509_verify_cert() has indicated
+an error or in a verification callback to determine the nature of an error.
+
+X509_STORE_CTX_get_error() returns the error code of B<ctx>, see
+the B<ERROR CODES> section for a full description of all error codes.
+
+X509_STORE_CTX_set_error() sets the error code of B<ctx> to B<s>. For example
+it might be used in a verification callback to set an error based on additional
+checks.
+
+X509_STORE_CTX_get_error_depth() returns the B<depth> of the error. This is a
+non-negative integer representing where in the certificate chain the error
+occurred. If it is zero it occured in the end entity certificate, one if
+it is the certificate which signed the end entity certificate and so on.
+
+X509_STORE_CTX_get_current_cert() returns the certificate in B<ctx> which
+caused the error or B<NULL> if no certificate is relevant.
+
+X509_STORE_CTX_get1_chain() returns a complete validate chain if a previous
+call to X509_verify_cert() is successful. If the call to X509_verify_cert()
+is B<not> successful the returned chain may be incomplete or invalid. The
+returned chain persists after the B<ctx> structure is freed, when it is
+no longer needed it should be free up using:
+
+  sk_X509_pop_free(chain, X509_free);
+
+X509_verify_cert_error_string() returns a human readable error string for
+verification error B<n>.
+
+=head1 RETURN VALUES
+
+X509_STORE_CTX_get_error() returns B<X509_V_OK> or an error code.
+
+X509_STORE_CTX_get_error_depth() returns a non-negative error depth.
+
+X509_STORE_CTX_get_current_cert() returns the cerificate which caused the
+error or B<NULL> if no certificate is relevant to the error.
+
+X509_verify_cert_error_string() returns a human readable error string for
+verification error B<n>.
+
+=head1 ERROR CODES
+
+A list of error codes and messages is shown below.  Some of the
+error codes are defined but currently never returned: these are described as
+"unused".
+
+=over 4
+
+=item B<X509_V_OK: ok>
+
+the operation was successful.
+
+=item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT: unable to get issuer certificate>
+
+the issuer certificate could not be found: this occurs if the issuer certificate
+of an untrusted certificate cannot be found.
+
+=item B<X509_V_ERR_UNABLE_TO_GET_CRL: unable to get certificate CRL>
+
+the CRL of a certificate could not be found.
+
+=item B<X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE: unable to decrypt certificate's signature>
+
+the certificate signature could not be decrypted. This means that the actual
+signature value could not be determined rather than it not matching the
+expected value, this is only meaningful for RSA keys.
+
+=item B<X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE: unable to decrypt CRL's signature>
+
+the CRL signature could not be decrypted: this means that the actual signature
+value could not be determined rather than it not matching the expected value.
+Unused.
+
+=item B<X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY: unable to decode issuer public key>
+
+the public key in the certificate SubjectPublicKeyInfo could not be read.
+
+=item B<X509_V_ERR_CERT_SIGNATURE_FAILURE: certificate signature failure>
+
+the signature of the certificate is invalid.
+
+=item B<X509_V_ERR_CRL_SIGNATURE_FAILURE: CRL signature failure>
+
+the signature of the certificate is invalid.
+
+=item B<X509_V_ERR_CERT_NOT_YET_VALID: certificate is not yet valid>
+
+the certificate is not yet valid: the notBefore date is after the current time.
+
+=item B<X509_V_ERR_CERT_HAS_EXPIRED: certificate has expired>
+
+the certificate has expired: that is the notAfter date is before the current time.
+
+=item B<X509_V_ERR_CRL_NOT_YET_VALID: CRL is not yet valid>
+
+the CRL is not yet valid.
+
+=item B<X509_V_ERR_CRL_HAS_EXPIRED: CRL has expired>
+
+the CRL has expired.
+
+=item B<X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: format error in certificate's notBefore field>
+
+the certificate notBefore field contains an invalid time.
+
+=item B<X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: format error in certificate's notAfter field>
+
+the certificate notAfter field contains an invalid time.
+
+=item B<X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD: format error in CRL's lastUpdate field>
+
+the CRL lastUpdate field contains an invalid time.
+
+=item B<X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD: format error in CRL's nextUpdate field>
+
+the CRL nextUpdate field contains an invalid time.
+
+=item B<X509_V_ERR_OUT_OF_MEM: out of memory>
+
+an error occurred trying to allocate memory. This should never happen.
+
+=item B<X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT: self signed certificate>
+
+the passed certificate is self signed and the same certificate cannot be found
+in the list of trusted certificates.
+
+=item B<X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN: self signed certificate in certificate chain>
+
+the certificate chain could be built up using the untrusted certificates but
+the root could not be found locally.
+
+=item B<X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY: unable to get local issuer certificate>
+
+the issuer certificate of a locally looked up certificate could not be found.
+This normally means the list of trusted certificates is not complete.
+
+=item B<X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE: unable to verify the first certificate>
+
+no signatures could be verified because the chain contains only one certificate
+and it is not self signed.
+
+=item B<X509_V_ERR_CERT_CHAIN_TOO_LONG: certificate chain too long>
+
+the certificate chain length is greater than the supplied maximum depth. Unused.
+
+=item B<X509_V_ERR_CERT_REVOKED: certificate revoked>
+
+the certificate has been revoked.
+
+=item B<X509_V_ERR_INVALID_CA: invalid CA certificate>
+
+a CA certificate is invalid. Either it is not a CA or its extensions are not
+consistent with the supplied purpose.
+
+=item B<X509_V_ERR_PATH_LENGTH_EXCEEDED: path length constraint exceeded>
+
+the basicConstraints pathlength parameter has been exceeded.
+
+=item B<X509_V_ERR_INVALID_PURPOSE: unsupported certificate purpose>
+
+the supplied certificate cannot be used for the specified purpose.
+
+=item B<X509_V_ERR_CERT_UNTRUSTED: certificate not trusted>
+
+the root CA is not marked as trusted for the specified purpose.
+
+=item B<X509_V_ERR_CERT_REJECTED: certificate rejected>
+
+the root CA is marked to reject the specified purpose.
+
+=item B<X509_V_ERR_SUBJECT_ISSUER_MISMATCH: subject issuer mismatch>
+
+the current candidate issuer certificate was rejected because its subject name
+did not match the issuer name of the current certificate. This is only set
+if issuer check debugging is enabled it is used for status notification and
+is B<not> in itself an error.
+
+=item B<X509_V_ERR_AKID_SKID_MISMATCH: authority and subject key identifier mismatch>
+
+the current candidate issuer certificate was rejected because its subject key
+identifier was present and did not match the authority key identifier current
+certificate. This is only set if issuer check debugging is enabled it is used
+for status notification and is B<not> in itself an error.
+
+=item B<X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH: authority and issuer serial number mismatch>
+
+the current candidate issuer certificate was rejected because its issuer name
+and serial number was present and did not match the authority key identifier of
+the current certificate. This is only set if issuer check debugging is enabled
+it is used for status notification and is B<not> in itself an error.
+
+=item B<X509_V_ERR_KEYUSAGE_NO_CERTSIGN:key usage does not include certificate signing>
+
+the current candidate issuer certificate was rejected because its keyUsage
+extension does not permit certificate signing. This is only set if issuer check
+debugging is enabled it is used for status notification and is B<not> in itself
+an error.
+
+=item B<X509_V_ERR_INVALID_EXTENSION: invalid or inconsistent certificate extension>
+
+A certificate extension had an invalid value (for example an incorrect
+encoding) or some value inconsistent with other extensions.
+
+
+=item B<X509_V_ERR_INVALID_POLICY_EXTENSION: invalid or inconsistent certificate policy extension>
+
+A certificate policies extension had an invalid value (for example an incorrect
+encoding) or some value inconsistent with other extensions. This error only
+occurs if policy processing is enabled.
+
+=item B<X509_V_ERR_NO_EXPLICIT_POLICY: no explicit policy>
+
+The verification flags were set to require and explicit policy but none was
+present.
+
+=item B<X509_V_ERR_DIFFERENT_CRL_SCOPE: Different CRL scope>
+
+The only CRLs that could be found did not match the scope of the certificate.
+
+=item B<X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE: Unsupported extension feature>
+
+Some feature of a certificate extension is not supported. Unused.
+
+=item B<X509_V_ERR_PERMITTED_VIOLATION: permitted subtree violation>
+
+A name constraint violation occured in the permitted subtrees.
+
+=item B<X509_V_ERR_EXCLUDED_VIOLATION: excluded subtree violation>
+
+A name constraint violation occured in the excluded subtrees.
+
+=item B<X509_V_ERR_SUBTREE_MINMAX: name constraints minimum and maximum not supported>
+
+A certificate name constraints extension included a minimum or maximum field:
+this is not supported.
+
+=item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_TYPE: unsupported name constraint type>
+
+An unsupported name constraint type was encountered. OpenSSL currently only
+supports directory name, DNS name, email and URI types.
+
+=item B<X509_V_ERR_UNSUPPORTED_CONSTRAINT_SYNTAX: unsupported or invalid name constraint syntax>
+
+The format of the name constraint is not recognised: for example an email
+address format of a form not mentioned in RFC3280. This could be caused by
+a garbage extension or some new feature not currently supported.
+
+=item B<X509_V_ERR_CRL_PATH_VALIDATION_ERROR: CRL path validation error>
+
+An error occured when attempting to verify the CRL path. This error can only
+happen if extended CRL checking is enabled.
+
+=item B<X509_V_ERR_APPLICATION_VERIFICATION: application verification failure>
+
+an application specific error. This will never be returned unless explicitly
+set by an application.
+
+=head1 NOTES
+
+The above functions should be used instead of directly referencing the fields
+in the B<X509_VERIFY_CTX> structure.
+
+In versions of OpenSSL before 1.0 the current certificate returned by
+X509_STORE_CTX_get_current_cert() was never B<NULL>. Applications should
+check the return value before printing out any debugging information relating
+to the current certificate.
+
+If an unrecognised error code is passed to X509_verify_cert_error_string() the
+numerical value of the unknown code is returned in a static buffer. This is not
+thread safe but will never happen unless an invalid code is passed.
+
+=head1 SEE ALSO
+
+L<X509_verify_cert(3)|X509_verify_cert(3)>
+
+=head1 HISTORY
+
+TBA
+
+=cut

doc/crypto/X509_STORE_CTX_get_ex_new_index.pod

@@ -0,0 +1,41 @@
+=pod
+
+=head1 NAME
+
+X509_STORE_CTX_get_ex_new_index, X509_STORE_CTX_set_ex_data, X509_STORE_CTX_get_ex_data - add application specific data to X509_STORE_CTX structures
+
+=head1 SYNOPSIS
+
+ #include <openssl/x509_vfy.h>
+
+ int X509_STORE_CTX_get_ex_new_index(long argl, void *argp,
+		CRYPTO_EX_new *new_func,
+		CRYPTO_EX_dup *dup_func,
+		CRYPTO_EX_free *free_func);
+
+ int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *d, int idx, void *arg);
+
+ char *X509_STORE_CTX_get_ex_data(X509_STORE_CTX *d, int idx);
+
+=head1 DESCRIPTION
+
+These functions handle application specific data in X509_STORE_CTX structures.
+Their usage is identical to that of RSA_get_ex_new_index(), RSA_set_ex_data()
+and RSA_get_ex_data() as described in L<RSA_get_ex_new_index(3)>.
+
+=head1 NOTES
+
+This mechanism is used internally by the B<ssl> library to store the B<SSL>
+structure associated with a verification operation in an B<X509_STORE_CTX>
+structure. 
+
+=head1 SEE ALSO
+
+L<RSA_get_ex_new_index(3)|RSA_get_ex_new_index(3)>
+
+=head1 HISTORY
+
+X509_STORE_CTX_get_ex_new_index(), X509_STORE_CTX_set_ex_data() and
+X509_STORE_CTX_get_ex_data() are available since OpenSSL 0.9.5.
+
+=cut

doc/crypto/X509_STORE_CTX_new.pod

@@ -0,0 +1,122 @@
+=pod
+
+=head1 NAME
+
+X509_STORE_CTX_new, X509_STORE_CTX_cleanup, X509_STORE_CTX_free, X509_STORE_CTX_init, X509_STORE_CTX_trusted_stack, X509_STORE_CTX_set_cert, X509_STORE_CTX_set_chain, X509_STORE_CTX_set0_crls, X509_STORE_CTX_get0_param, X509_STORE_CTX_set0_param, X509_STORE_CTX_set_default - X509_STORE_CTX initialisation
+
+=head1 SYNOPSIS
+
+ #include <openssl/x509_vfy.h>
+
+ X509_STORE_CTX *X509_STORE_CTX_new(void);
+ void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx);
+ void X509_STORE_CTX_free(X509_STORE_CTX *ctx);
+
+ int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store,
+			 X509 *x509, STACK_OF(X509) *chain);
+
+ void X509_STORE_CTX_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk);
+
+ void	X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx,X509 *x);
+ void	X509_STORE_CTX_set_chain(X509_STORE_CTX *ctx,STACK_OF(X509) *sk);
+ void	X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk);
+
+ X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx);
+ void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param);
+ int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name);
+
+=head1 DESCRIPTION
+
+These functions initialise an B<X509_STORE_CTX> structure for subsequent use
+by X509_verify_cert().
+
+X509_STORE_CTX_new() returns a newly initialised B<X509_STORE_CTX> structure.
+
+X509_STORE_CTX_cleanup() internally cleans up an B<X509_STORE_CTX> structure.
+The context can then be reused with an new call to X509_STORE_CTX_init().
+
+X509_STORE_CTX_free() completely frees up B<ctx>. After this call B<ctx>
+is no longer valid.
+
+X509_STORE_CTX_init() sets up B<ctx> for a subsequent verification operation.
+The trusted certificate store is set to B<store>, the end entity certificate
+to be verified is set to B<x509> and a set of additional certificates (which
+will be untrusted but may be used to build the chain) in B<chain>. Any or
+all of the B<store>, B<x509> and B<chain> parameters can be B<NULL>.
+
+X509_STORE_CTX_trusted_stack() sets the set of trusted certificates of B<ctx>
+to B<sk>. This is an alternative way of specifying trusted certificates 
+instead of using an B<X509_STORE>.
+
+X509_STORE_CTX_set_cert() sets the certificate to be vertified in B<ctx> to
+B<x>.
+
+X509_STORE_CTX_set_chain() sets the additional certificate chain used by B<ctx>
+to B<sk>.
+
+X509_STORE_CTX_set0_crls() sets a set of CRLs to use to aid certificate
+verification to B<sk>. These CRLs will only be used if CRL verification is
+enabled in the associated B<X509_VERIFY_PARAM> structure. This might be
+used where additional "useful" CRLs are supplied as part of a protocol,
+for example in a PKCS#7 structure.
+
+X509_VERIFY_PARAM *X509_STORE_CTX_get0_param() retrieves an intenal pointer
+to the verification parameters associated with B<ctx>.
+
+X509_STORE_CTX_set0_param() sets the intenal verification parameter pointer
+to B<param>. After this call B<param> should not be used.
+
+X509_STORE_CTX_set_default() looks up and sets the default verification
+method to B<name>. This uses the function X509_VERIFY_PARAM_lookup() to
+find an appropriate set of parameters from B<name>.
+
+=head1 NOTES
+
+The certificates and CRLs in a store are used internally and should B<not>
+be freed up until after the associated B<X509_STORE_CTX> is freed. Legacy
+applications might implicitly use an B<X509_STORE_CTX> like this:
+
+  X509_STORE_CTX ctx;
+  X509_STORE_CTX_init(&ctx, store, cert, chain);
+
+this is B<not> recommended in new applications they should instead do:
+
+  X509_STORE_CTX *ctx;
+  ctx = X509_STORE_CTX_new();
+  if (ctx == NULL)
+	/* Bad error */
+  X509_STORE_CTX_init(ctx, store, cert, chain);
+
+=head1 BUGS
+
+The certificates and CRLs in a context are used internally and should B<not>
+be freed up until after the associated B<X509_STORE_CTX> is freed. Copies
+should be made or reference counts increased instead.
+
+=head1 RETURN VALUES
+
+X509_STORE_CTX_new() returns an newly allocates context or B<NULL> is an
+error occurred.
+
+X509_STORE_CTX_init() returns 1 for success or 0 if an error occurred.
+
+X509_STORE_CTX_get0_param() returns a pointer to an B<X509_VERIFY_PARAM>
+structure or B<NULL> if an error occurred.
+
+X509_STORE_CTX_cleanup(), X509_STORE_CTX_free(), X509_STORE_CTX_trusted_stack(),
+X509_STORE_CTX_set_cert(), X509_STORE_CTX_set_chain(),
+X509_STORE_CTX_set0_crls() and X509_STORE_CTX_set0_param() do not return
+values.
+
+X509_STORE_CTX_set_default() returns 1 for success or 0 if an error occurred.
+
+=head1 SEE ALSO
+
+L<X509_verify_cert(3)|X509_verify_cert(3)>
+L<X509_VERIFY_PARAM_set_flags(3)|X509_VERIFY_PARAM_set_flags(3)>
+
+=head1 HISTORY
+
+X509_STORE_CTX_set0_crls() was first added to OpenSSL 1.0.0
+
+=cut

doc/crypto/X509_STORE_CTX_set_verify_cb.pod

@@ -0,0 +1,161 @@
+=pod
+
+=head1 NAME
+
+X509_STORE_CTX_set_verify_cb - set verification callback
+
+=head1 SYNOPSIS
+
+ #include <openssl/x509_vfy.h>
+
+ void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
+				int (*verify_cb)(int ok, X509_STORE_CTX *ctx));
+
+=head1 DESCRIPTION
+
+X509_STORE_CTX_set_verify_cb() sets the verification callback of B<ctx> to
+B<verify_cb> overwriting any existing callback.
+
+The verification callback can be used to customise the operation of certificate
+verification, either by overriding error conditions or logging errors for
+debugging purposes.
+
+However a verification callback is B<not> essential and the default operation
+is often sufficient.
+
+The B<ok> parameter to the callback indicates the value the callback should
+return to retain the default behaviour. If it is zero then and error condition
+is indicated. If it is 1 then no error occurred. If the flag
+B<X509_V_FLAG_NOTIFY_POLICY> is set then B<ok> is set to 2 to indicate the
+policy checking is complete.
+
+The B<ctx> parameter to the callback is the B<X509_STORE_CTX> structure that
+is performing the verification operation. A callback can examine this
+structure and receive additional information about the error, for example
+by calling X509_STORE_CTX_get_current_cert(). Additional application data can
+be passed to the callback via the B<ex_data> mechanism.
+
+=head1 WARNING
+
+In general a verification callback should B<NOT> unconditionally return 1 in
+all circumstances because this will allow verification to succeed no matter
+what the error. This effectively removes all security from the application
+because B<any> certificate (including untrusted generated ones) will be
+accepted.
+
+=head1 NOTES
+
+The verification callback can be set and inherited from the parent structure
+performing the operation. In some cases (such as S/MIME verification) the
+B<X509_STORE_CTX> structure is created and destroyed internally and the
+only way to set a custom verification callback is by inheriting it from the
+associated B<X509_STORE>.
+
+=head1 RETURN VALUES
+
+X509_STORE_CTX_set_verify_cb() does not return a value.
+
+=head1 EXAMPLES
+
+Default callback operation:
+
+ int verify_callback(int ok, X509_STORE_CTX *ctx)
+	{
+	return ok;
+	}
+
+Simple example, suppose a certificate in the chain is expired and we wish
+to continue after this error:
+
+ int verify_callback(int ok, X509_STORE_CTX *ctx)
+	{
+	/* Tolerate certificate expiration */
+	if (X509_STORE_CTX_get_error(ctx) == X509_V_ERR_CERT_HAS_EXPIRED)
+			return 1;
+	/* Otherwise don't override */
+	return ok;
+	}
+
+More complex example, we don't wish to continue after B<any> certificate has
+expired just one specific case:
+
+ int verify_callback(int ok, X509_STORE_CTX *ctx)
+	{
+	int err = X509_STORE_CTX_get_error(ctx);
+	X509 *err_cert = X509_STORE_CTX_get_current_cert(ctx);
+	if (err == X509_V_ERR_CERT_HAS_EXPIRED)
+		{
+		if (check_is_acceptable_expired_cert(err_cert)
+			return 1;
+		}
+	return ok;
+	}
+
+Full featured logging callback. In this case the B<bio_err> is assumed to be
+a global logging B<BIO>, an alternative would to store a BIO in B<ctx> using
+B<ex_data>.
+	
+ int verify_callback(int ok, X509_STORE_CTX *ctx)
+	{
+	X509 *err_cert;
+	int err,depth;
+
+	err_cert = X509_STORE_CTX_get_current_cert(ctx);
+	err =	X509_STORE_CTX_get_error(ctx);
+	depth =	X509_STORE_CTX_get_error_depth(ctx);
+
+	BIO_printf(bio_err,"depth=%d ",depth);
+	if (err_cert)
+		{
+		X509_NAME_print_ex(bio_err, X509_get_subject_name(err_cert),
+					0, XN_FLAG_ONELINE);
+		BIO_puts(bio_err, "\n");
+		}
+	else
+		BIO_puts(bio_err, "<no cert>\n");
+	if (!ok)
+		BIO_printf(bio_err,"verify error:num=%d:%s\n",err,
+			X509_verify_cert_error_string(err));
+	switch (err)
+		{
+	case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
+		BIO_puts(bio_err,"issuer= ");
+		X509_NAME_print_ex(bio_err, X509_get_issuer_name(err_cert),
+					0, XN_FLAG_ONELINE);
+		BIO_puts(bio_err, "\n");
+		break;
+	case X509_V_ERR_CERT_NOT_YET_VALID:
+	case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
+		BIO_printf(bio_err,"notBefore=");
+		ASN1_TIME_print(bio_err,X509_get_notBefore(err_cert));
+		BIO_printf(bio_err,"\n");
+		break;
+	case X509_V_ERR_CERT_HAS_EXPIRED:
+	case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
+		BIO_printf(bio_err,"notAfter=");
+		ASN1_TIME_print(bio_err,X509_get_notAfter(err_cert));
+		BIO_printf(bio_err,"\n");
+		break;
+	case X509_V_ERR_NO_EXPLICIT_POLICY:
+		policies_print(bio_err, ctx);
+		break;
+		}
+	if (err == X509_V_OK && ok == 2)
+		/* print out policies */
+
+	BIO_printf(bio_err,"verify return:%d\n",ok);
+	return(ok);
+	}
+
+=head1 SEE ALSO
+
+L<X509_STORE_CTX_get_error(3)|X509_STORE_CTX_get_error(3)>
+L<X509_STORE_set_verify_cb_func(3)|X509_STORE_set_verify_cb_func(3)>
+L<X509_STORE_CTX_get_ex_new_index(3)|X509_STORE_CTX_get_ex_new_index(3)>
+
+=head1 HISTORY
+
+X509_STORE_CTX_set_verify_cb() is available in all versions of SSLeay and
+OpenSSL.
+
+=cut

doc/crypto/X509_STORE_set_verify_cb_func.pod

@@ -0,0 +1,54 @@
+=pod
+
+=head1 NAME
+
+X509_STORE_set_verify_cb_func, X509_STORE_set_verify_cb - set verification callback
+
+=head1 SYNOPSIS
+
+ #include <openssl/x509_vfy.h>
+
+ void X509_STORE_set_verify_cb(X509_STORE *st,
+				int (*verify_cb)(int ok, X509_STORE_CTX *ctx));
+
+ void X509_STORE_set_verify_cb_func(X509_STORE *st,
+				int (*verify_cb)(int ok, X509_STORE_CTX *ctx));
+
+=head1 DESCRIPTION
+
+X509_STORE_set_verify_cb() sets the verification callback of B<ctx> to
+B<verify_cb> overwriting any existing callback.
+
+X509_STORE_set_verify_cb_func() also sets the verification callback but it
+is implemented as a macro.
+
+=head 1 NOTES
+
+The verification callback from an B<X509_STORE> is inherited by 
+the corresponding B<X509_STORE_CTX> structure when it is initialized. This can
+be used to set the verification callback when the B<X509_STORE_CTX> is 
+otherwise inaccessible (for example during S/MIME verification).
+
+=head1 BUGS
+
+The macro version of this function was the only one available before 
+OpenSSL 1.0.0.
+
+=head1 RETURN VALUES
+
+X509_STORE_set_verify_cb() and X509_STORE_set_verify_cb_func() do not return
+a value.
+
+=head1 SEE ALSO
+
+L<X509_STORE_CTX_set_verify_cb(3)|X509_STORE_CTX_set_verify_cb(3)>
+L<CMS_verify(3)|CMS_verify(3)>
+
+=head1 HISTORY
+
+X509_STORE_set_verify_cb_func() is available in all versions of SSLeay and
+OpenSSL.
+
+X509_STORE_set_verify_cb() was added to OpenSSL 1.0.0.
+
+=cut

doc/crypto/X509_VERIFY_PARAM_set_flags.pod

@@ -0,0 +1,171 @@
+=pod
+
+=head1 NAME
+
+X509_VERIFY_PARAM_set_flags, X509_VERIFY_PARAM_clear_flags, X509_VERIFY_PARAM_get_flags, X509_VERIFY_PARAM_set_purpose, X509_VERIFY_PARAM_set_trust, X509_VERIFY_PARAM_set_depth, X509_VERIFY_PARAM_get_depth, X509_VERIFY_PARAM_set_time, X509_VERIFY_PARAM_add0_policy, X509_VERIFY_PARAM_set1_policies - X509 verification parameters 
+
+=head1 SYNOPSIS
+
+ #include <openssl/x509_vfy.h>
+
+ int X509_VERIFY_PARAM_set_flags(X509_VERIFY_PARAM *param, unsigned long flags);
+ int X509_VERIFY_PARAM_clear_flags(X509_VERIFY_PARAM *param,
+							unsigned long flags);
+ unsigned long X509_VERIFY_PARAM_get_flags(X509_VERIFY_PARAM *param);
+
+ int X509_VERIFY_PARAM_set_purpose(X509_VERIFY_PARAM *param, int purpose);
+ int X509_VERIFY_PARAM_set_trust(X509_VERIFY_PARAM *param, int trust);
+
+ void X509_VERIFY_PARAM_set_time(X509_VERIFY_PARAM *param, time_t t);
+
+ int X509_VERIFY_PARAM_add0_policy(X509_VERIFY_PARAM *param,
+						ASN1_OBJECT *policy);
+ int X509_VERIFY_PARAM_set1_policies(X509_VERIFY_PARAM *param, 
+					STACK_OF(ASN1_OBJECT) *policies);
+
+ void X509_VERIFY_PARAM_set_depth(X509_VERIFY_PARAM *param, int depth);
+ int X509_VERIFY_PARAM_get_depth(const X509_VERIFY_PARAM *param);
+
+=head1 DESCRIPTION
+
+These functions manipulate the B<X509_VERIFY_PARAM> structure associated with
+a certificate verification operation. 
+
+The X509_VERIFY_PARAM_set_flags() function sets the flags in B<param> by oring
+it with B<flags>. See the B<VERIFICATION FLAGS> section for a complete
+description of values the B<flags> parameter can take.
+
+X509_VERIFY_PARAM_get_flags() returns the flags in B<param>.
+
+X509_VERIFY_PARAM_clear_flags() clears the flags B<flags> in B<param>.
+
+X509_VERIFY_PARAM_set_purpose() sets the verification purpose in B<param>
+to B<purpose>. This determines the acceptable purpose of the certificate
+chain, for example SSL client or SSL server.
+
+X509_VERIFY_PARAM_set_trust() sets the trust setting in B<param> to 
+B<trust>.
+
+X509_VERIFY_PARAM_set_time() sets the verification time in B<param> to
+B<t>. Normally the current time is used.
+
+X509_VERIFY_PARAM_add0_policy() enables policy checking (it is disabled
+by default) and adds B<policy> to the acceptable policy set.
+
+X509_VERIFY_PARAM_set1_policies() enables policy checking (it is disabled
+by default) and sets the acceptable policy set to B<policies>. Any existing
+policy set is cleared. The B<policies> parameter can be B<NULL> to clear
+an existing policy set.
+
+X509_VERIFY_PARAM_set_depth() sets the maximum verification depth to B<depth>.
+That is the maximum number of untrusted CA certificates that can appear in a
+chain.
+
+=head1 RETURN VALUES
+
+X509_VERIFY_PARAM_set_flags(), X509_VERIFY_PARAM_clear_flags(), 
+X509_VERIFY_PARAM_set_purpose(), X509_VERIFY_PARAM_set_trust(),
+X509_VERIFY_PARAM_add0_policy() and X509_VERIFY_PARAM_set1_policies() return 1
+for success and 0 for failure. 
+
+X509_VERIFY_PARAM_get_flags() returns the current verification flags.
+
+X509_VERIFY_PARAM_set_time() and X509_VERIFY_PARAM_set_depth() do not return
+values.
+
+X509_VERIFY_PARAM_get_depth() returns the current verification depth.
+
+=head1 VERIFICATION FLAGS
+
+The verification flags consists of zero or more of the following flags
+ored together.
+
+B<X509_V_FLAG_CRL_CHECK> enables CRL checking for the certificate chain leaf
+certificate. An error occurs if a suitable CRL cannot be found. 
+
+B<X509_V_FLAG_CRL_CHECK_ALL> enables CRL checking for the entire certificate
+chain.
+
+B<X509_V_FLAG_IGNORE_CRITICAL> disabled critical extension checking. By default
+any unhandled critical extensions in certificates or (if checked) CRLs results
+in a fatal error. If this flag is set unhandled critical extensions are
+ignored. B<WARNING> setting this option for anything other than debugging
+purposes can be a security risk. Finer control over which extensions are
+supported can be performed in the verification callback.
+
+THe B<X509_V_FLAG_X509_STRICT> flag disables workarounds for some broken
+certificates and makes the verification strictly apply B<X509> rules.
+
+B<X509_V_FLAG_ALLOW_PROXY_CERTS> enables proxy certificate verification.
+
+B<X509_V_FLAG_POLICY_CHECK> enables certificate policy checking, by default
+no policy checking is peformed. Additional information is sent to the 
+verification callback relating to policy checking.
+
+B<X509_V_FLAG_EXPLICIT_POLICY>, B<X509_V_FLAG_INHIBIT_ANY> and
+B<X509_V_FLAG_INHIBIT_MAP> set the B<require explicit policy>, B<inhibit any
+policy> and B<inhibit policy mapping> flags respectively as defined in
+B<RFC3280>. Policy checking is automatically enabled if any of these flags
+are set.
+
+If B<X509_V_FLAG_NOTIFY_POLICY> is set and the policy checking is successful
+a special status code is set to the verification callback. This permits it
+to examine the valid policy tree and perform additional checks or simply
+log it for debugging purposes.
+
+By default some addtional features such as indirect CRLs and CRLs signed by
+different keys are disabled. If B<X509_V_FLAG_EXTENDED_CRL_SUPPORT> is set
+they are enabled.
+
+If B<X509_V_FLAG_USE_DELTAS> ise set delta CRLs (if present) are used to
+determine certificate status. If not set deltas are ignored.
+
+B<X509_V_FLAG_CHECK_SS_SIGNATURE> enables checking of the root CA self signed
+cerificate signature. By default this check is disabled because it doesn't
+add any additional security but in some cases applications might want to
+check the signature anyway. A side effect of not checking the root CA
+signature is that disabled or unsupported message digests on the root CA
+are not treated as fatal errors.
+
+The B<X509_V_FLAG_CB_ISSUER_CHECK> flag enables debugging of certificate
+issuer checks. It is B<not> needed unless you are logging certificate
+verification. If this flag is set then additional status codes will be sent
+to the verification callback and it B<must> be prepared to handle such cases
+without assuming they are hard errors.
+
+=head1 NOTES
+
+The above functions should be used to manipulate verification parameters
+instead of legacy functions which work in specific structures such as
+X509_STORE_CTX_set_flags().
+
+=head1 BUGS
+
+Delta CRL checking is currently primitive. Only a single delta can be used and
+(partly due to limitations of B<X509_STORE>) constructed CRLs are not 
+maintained.
+
+If CRLs checking is enable CRLs are expected to be available in the
+corresponding B<X509_STORE> structure. No attempt is made to download
+CRLs from the CRL distribution points extension.
+
+=head1 EXAMPLE
+
+Enable CRL checking when performing certificate verification during SSL 
+connections associated with an B<SSL_CTX> structure B<ctx>:
+
+  X509_VERIFY_PARAM *param;
+  param = X509_VERIFY_PARAM_new();
+  X509_VERIFY_PARAM_set_flags(param, X509_V_FLAG_CRL_CHECK);
+  SSL_CTX_set1_param(ctx, param);
+  X509_VERIFY_PARAM_free(param);
+
+=head1 SEE ALSO
+
+L<X509_verify_cert(3)|X509_verify_cert(3)>
+
+=head1 HISTORY
+
+TBA
+
+=cut

doc/crypto/X509_verify_cert.pod

@@ -0,0 +1,53 @@
+=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