As with RSA, which was modified recently, this change makes it possible to

override key-generation implementations by placing handlers in the methods
for DSA and DH. Also, parameter generation for DSA and DH is possible by
another new handler for each method.

4 files changed, 33 insertions, 0 deletions

diff --git a/crypto/dsa/dsa.h b/crypto/dsa/dsa.h
index 7a126e486b..6ba79b01df 100644
--- a/crypto/dsa/dsa.h
+++ b/crypto/dsa/dsa.h
@@ -110,6 +110,13 @@ typedef struct dsa_method {
 	int (*finish)(DSA *dsa);
 	int flags;
 	char *app_data;
+	/* If this is non-NULL, it is used to generate DSA parameters */
+	int (*dsa_paramgen)(DSA *dsa, int bits,
+			unsigned char *seed, int seed_len,
+			int *counter_ret, unsigned long *h_ret,
+			BN_GENCB *cb);
+	/* If this is non-NULL, it is used to generate DSA keys */
+	int (*dsa_keygen)(DSA *dsa);
 } DSA_METHOD;
 
 struct dsa_st
diff --git a/crypto/dsa/dsa_gen.c b/crypto/dsa/dsa_gen.c
index ca2c867089..4b9aff3689 100644
--- a/crypto/dsa/dsa_gen.c
+++ b/crypto/dsa/dsa_gen.c
@@ -80,10 +80,25 @@
 #include <openssl/rand.h>
 #include <openssl/sha.h>
 
+static int dsa_builtin_paramgen(DSA *ret, int bits,
+		unsigned char *seed_in, int seed_len,
+		int *counter_ret, unsigned long *h_ret, BN_GENCB *cb);
+
 int DSA_generate_parameters_ex(DSA *ret, int bits,
 		unsigned char *seed_in, int seed_len,
 		int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
 	{
+	if(ret->meth->dsa_paramgen)
+		return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len,
+				counter_ret, h_ret, cb);
+	return dsa_builtin_paramgen(ret, bits, seed_in, seed_len,
+			counter_ret, h_ret, cb);
+	}
+
+static int dsa_builtin_paramgen(DSA *ret, int bits,
+		unsigned char *seed_in, int seed_len,
+		int *counter_ret, unsigned long *h_ret, BN_GENCB *cb)
+	{
 	int ok=0;
 	unsigned char seed[SHA_DIGEST_LENGTH];
 	unsigned char md[SHA_DIGEST_LENGTH];
diff --git a/crypto/dsa/dsa_key.c b/crypto/dsa/dsa_key.c
index ef87c3e637..48ff1f423c 100644
--- a/crypto/dsa/dsa_key.c
+++ b/crypto/dsa/dsa_key.c
@@ -64,8 +64,17 @@
 #include <openssl/dsa.h>
 #include <openssl/rand.h>
 
+static int dsa_builtin_keygen(DSA *dsa);
+
 int DSA_generate_key(DSA *dsa)
 	{
+	if(dsa->meth->dsa_keygen)
+		return dsa->meth->dsa_keygen(dsa);
+	return dsa_builtin_keygen(dsa);
+	}
+
+static int dsa_builtin_keygen(DSA *dsa)
+	{
 	int ok=0;
 	BN_CTX *ctx=NULL;
 	BIGNUM *pub_key=NULL,*priv_key=NULL;
diff --git a/crypto/dsa/dsa_ossl.c b/crypto/dsa/dsa_ossl.c
index fc35dfe1f6..313c06fa3f 100644
--- a/crypto/dsa/dsa_ossl.c
+++ b/crypto/dsa/dsa_ossl.c
@@ -89,6 +89,8 @@ dsa_bn_mod_exp,
 dsa_init,
 dsa_finish,
 0,
+NULL,
+NULL,
 NULL
 };