port necessary dsa functions to openssl 1.0.2

dsa.go

@@ -81,7 +81,11 @@ func GenerateDSAParameters(L, N int) (DSAParameters, error) {
 	switch vMajor {
 	case 1:
 		dsa := getDSA(pkey)
-		C.go_openssl_DSA_get0_pqg(dsa, &p, &q, &g)
+		if vMinor == 0 {
+			C.go_openssl_DSA_get0_pqg_backport(dsa, &p, &q, &g)
+		} else {
+			C.go_openssl_DSA_get0_pqg(dsa, &p, &q, &g)
+		}
 	case 3:
 		defer func() {
 			C.go_openssl_BN_free(p)
@@ -142,7 +146,11 @@ func GenerateKeyDSA(params DSAParameters) (*PrivateKeyDSA, error) {
 	switch vMajor {
 	case 1:
 		dsa := getDSA(pkey)
-		C.go_openssl_DSA_get0_key(dsa, &y, &x)
+		if vMinor == 0 {
+			C.go_openssl_DSA_get0_key_backport(dsa, &y, &x)
+		} else {
+			C.go_openssl_DSA_get0_key(dsa, &y, &x)
+		}
 	case 3:
 		defer func() {
 			C.go_openssl_BN_clear_free(x)
@@ -187,7 +195,13 @@ func newDSA1(params DSAParameters, X, Y BigInt) (C.GO_EVP_PKEY_PTR, error) {
 	}
 	dsa := C.go_openssl_DSA_new()
 	p, q, g := bigToBN(params.P), bigToBN(params.Q), bigToBN(params.G)
-	if C.go_openssl_DSA_set0_pqg(dsa, p, q, g) != 1 {
+	var ret C.int
+	if vMinor == 0 {
+		ret = C.go_openssl_DSA_set0_pqg_backport(dsa, p, q, g)
+	} else {
+		ret = C.go_openssl_DSA_set0_pqg(dsa, p, q, g)
+	}
+	if ret != 1 {
 		C.go_openssl_BN_free(p)
 		C.go_openssl_BN_free(q)
 		C.go_openssl_BN_free(g)
@@ -196,7 +210,12 @@ func newDSA1(params DSAParameters, X, Y BigInt) (C.GO_EVP_PKEY_PTR, error) {
 	}
 	if Y != nil {
 		pub, priv := bigToBN(Y), bigToBN(X)
-		if C.go_openssl_DSA_set0_key(dsa, pub, priv) != 1 {
+		if vMinor == 0 {
+			ret = C.go_openssl_DSA_set0_key_backport(dsa, pub, priv)
+		} else {
+			ret = C.go_openssl_DSA_set0_key(dsa, pub, priv)
+		}
+		if ret != 1 {
 			C.go_openssl_BN_free(pub)
 			C.go_openssl_BN_clear_free(priv)
 			C.go_openssl_DSA_free(dsa)

goopenssl.h

@@ -28,6 +28,10 @@ int go_openssl_version_patch(void* handle);
 int go_openssl_thread_setup(void);
 void go_openssl_load_functions(void* handle, unsigned int major, unsigned int minor, unsigned int patch);
 const GO_EVP_MD_PTR go_openssl_EVP_md5_sha1_backport(void);
+void go_openssl_DSA_get0_pqg_backport(const GO_DSA_PTR d, GO_BIGNUM_PTR *p, GO_BIGNUM_PTR *q, GO_BIGNUM_PTR *g);
+int go_openssl_DSA_set0_pqg_backport(GO_DSA_PTR d, GO_BIGNUM_PTR p, GO_BIGNUM_PTR q, GO_BIGNUM_PTR g);
+void go_openssl_DSA_get0_key_backport(const GO_DSA_PTR d, GO_BIGNUM_PTR *pub_key, GO_BIGNUM_PTR *priv_key);
+int go_openssl_DSA_set0_key_backport(GO_DSA_PTR d, GO_BIGNUM_PTR pub_key, GO_BIGNUM_PTR priv_key);
 
 // Define pointers to all the used OpenSSL functions.
 // Calling C function pointers from Go is currently not supported.

port_dsa.c

@@ -0,0 +1,83 @@
+// The following is a partial backport of crypto/dsa/dsa_pmeth.c,
+// commit cbc8a839959418d8a2c2e3ec6bdf394852c9501e on the
+// OpenSSL_1_1_0-stable branch.  The ctrl function has been removed.
+
+#include "goopenssl.h"
+
+struct dsa_st
+{
+    int _ignored0;
+    long _ignored1;
+    int _ignored2;
+    GO_BIGNUM_PTR p;
+    GO_BIGNUM_PTR q;
+    GO_BIGNUM_PTR g;
+    GO_BIGNUM_PTR pub_key;
+    GO_BIGNUM_PTR priv_key;
+};
+
+
+void go_openssl_DSA_get0_pqg_backport(const GO_DSA_PTR dsa,
+                  GO_BIGNUM_PTR *p, GO_BIGNUM_PTR *q, GO_BIGNUM_PTR *g)
+{
+    const struct dsa_st *d = dsa;
+    if (p != NULL)
+        *p = d->p;
+    if (q != NULL)
+        *q = d->q;
+    if (g != NULL)
+        *g = d->g;
+}
+
+int go_openssl_DSA_set0_pqg_backport(GO_DSA_PTR dsa,
+                  GO_BIGNUM_PTR p, GO_BIGNUM_PTR q, GO_BIGNUM_PTR g)
+{
+    struct dsa_st *d = dsa;
+    if ((d->p == NULL && p == NULL)
+        || (d->q == NULL && q == NULL)
+        || (d->g == NULL && g == NULL))
+        return 0;
+
+    if (p != NULL) {
+        go_openssl_BN_free(d->p);
+        d->p = p;
+    }
+    if (q != NULL) {
+        go_openssl_BN_free(d->q);
+        d->q = q;
+    }
+    if (g != NULL) {
+        go_openssl_BN_free(d->g);
+        d->g = g;
+    }
+
+    return 1;
+}
+
+void go_openssl_DSA_get0_key_backport(const GO_DSA_PTR dsa,
+                  GO_BIGNUM_PTR *pub_key, GO_BIGNUM_PTR *priv_key)
+{
+    const struct dsa_st *d = dsa;
+    if (pub_key != NULL)
+        *pub_key = d->pub_key;
+    if (priv_key != NULL)
+        *priv_key = d->priv_key;
+}
+
+int go_openssl_DSA_set0_key_backport(GO_DSA_PTR dsa, GO_BIGNUM_PTR pub_key, GO_BIGNUM_PTR priv_key)
+{
+    struct dsa_st *d = dsa;
+    if (d->pub_key == NULL && pub_key == NULL)
+        return 0;
+
+    if (pub_key != NULL) {
+        go_openssl_BN_free(d->pub_key);
+        d->pub_key = pub_key;
+    }
+    if (priv_key != NULL) {
+        go_openssl_BN_free(d->priv_key);
+        d->priv_key = priv_key;
+    }
+
+    return 1;
+}