This is a first-cut at improving the callback mechanisms used in

key-generation and prime-checking functions. Rather than explicitly passing
callback functions and caller-defined context data for the callbacks, a new
structure BN_GENCB is defined that encapsulates this; a pointer to the
structure is passed to all such functions instead.

This wrapper structure allows the encapsulation of "old" and "new" style
callbacks - "new" callbacks return a boolean result on the understanding
that returning FALSE should terminate keygen/primality processing.  The
BN_GENCB abstraction will allow future callback modifications without
needing to break binary compatibility nor change the API function
prototypes. The new API functions have been given names ending in "_ex" and
the old functions are implemented as wrappers to the new ones.  The
OPENSSL_NO_DEPRECATED symbol has been introduced so that, if defined,
declaration of the older functions will be skipped. NB: Some
openssl-internal code will stick with the older callbacks for now, so
appropriate "#undef" logic will be put in place - this is in case the user
is *building* openssl (rather than *including* its headers) with this
symbol defined.

There is another change in the new _ex functions; the key-generation
functions do not return key structures but operate on structures passed by
the caller, the return value is a boolean. This will allow for a smoother
transition to having key-generation as "virtual function" in the various
***_METHOD tables.

1 files changed, 10 insertions, 0 deletions

diff --git a/crypto/dsa/dsa.h b/crypto/dsa/dsa.h
index 9b3baadf2c..7a126e486b 100644
--- a/crypto/dsa/dsa.h
+++ b/crypto/dsa/dsa.h
@@ -186,10 +186,20 @@ void *DSA_get_ex_data(DSA *d, int idx);
 DSA *	d2i_DSAPublicKey(DSA **a, const unsigned char **pp, long length);
 DSA *	d2i_DSAPrivateKey(DSA **a, const unsigned char **pp, long length);
 DSA * 	d2i_DSAparams(DSA **a, const unsigned char **pp, long length);
+
+/* Deprecated version */
+#ifndef OPENSSL_NO_DEPRECATED
 DSA *	DSA_generate_parameters(int bits,
 		unsigned char *seed,int seed_len,
 		int *counter_ret, unsigned long *h_ret,void
 		(*callback)(int, int, void *),void *cb_arg);
+#endif /* !defined(OPENSSL_NO_DEPRECATED) */
+
+/* New version */
+int	DSA_generate_parameters_ex(DSA *dsa, int bits,
+		unsigned char *seed,int seed_len,
+		int *counter_ret, unsigned long *h_ret, BN_GENCB *cb);
+
 int	DSA_generate_key(DSA *a);
 int	i2d_DSAPublicKey(const DSA *a, unsigned char **pp);
 int 	i2d_DSAPrivateKey(const DSA *a, unsigned char **pp);