Add FFC param/key validation

Embed libctx in dsa and dh objects and cleanup internal methods to not pass libctx (This makes it consistent with the rsa changes)

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10910)

1 files changed, 24 insertions, 25 deletions

diff --git a/crypto/dsa/dsa_key.c b/crypto/dsa/dsa_key.c
index 00e7213b97..c93ea15b76 100644
--- a/crypto/dsa/dsa_key.c
+++ b/crypto/dsa/dsa_key.c
@@ -20,31 +20,43 @@
 #include "crypto/dsa.h"
 #include "dsa_local.h"
 
-static int dsa_builtin_keygen(OPENSSL_CTX *libctx, DSA *dsa);
+static int dsa_builtin_keygen(DSA *dsa);
 
 int DSA_generate_key(DSA *dsa)
 {
+#ifndef FIPS_MODE
     if (dsa->meth->dsa_keygen != NULL)
         return dsa->meth->dsa_keygen(dsa);
-    return dsa_builtin_keygen(NULL, dsa);
+#endif
+    return dsa_builtin_keygen(dsa);
 }
 
-int dsa_generate_key_ctx(OPENSSL_CTX *libctx, DSA *dsa)
+int dsa_generate_public_key(BN_CTX *ctx, const DSA *dsa, const BIGNUM *priv_key,
+                            BIGNUM *pub_key)
 {
-#ifndef FIPS_MODE
-    if (dsa->meth->dsa_keygen != NULL)
-        return dsa->meth->dsa_keygen(dsa);
-#endif
-    return dsa_builtin_keygen(libctx, dsa);
+    int ret = 0;
+    BIGNUM *prk = BN_new();
+
+    if (prk == NULL)
+        return 0;
+    BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
+
+    /* pub_key = g ^ priv_key mod p */
+    if (!BN_mod_exp(pub_key, dsa->params.g, prk, dsa->params.p, ctx))
+        goto err;
+    ret = 1;
+err:
+    BN_clear_free(prk);
+    return ret;
 }
 
-static int dsa_builtin_keygen(OPENSSL_CTX *libctx, DSA *dsa)
+static int dsa_builtin_keygen(DSA *dsa)
 {
     int ok = 0;
     BN_CTX *ctx = NULL;
     BIGNUM *pub_key = NULL, *priv_key = NULL;
 
-    if ((ctx = BN_CTX_new_ex(libctx)) == NULL)
+    if ((ctx = BN_CTX_new_ex(dsa->libctx)) == NULL)
         goto err;
 
     if (dsa->priv_key == NULL) {
@@ -65,21 +77,8 @@ static int dsa_builtin_keygen(OPENSSL_CTX *libctx, DSA *dsa)
         pub_key = dsa->pub_key;
     }
 
-    {
-        BIGNUM *prk = BN_new();
-
-        if (prk == NULL)
-            goto err;
-        BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
-
-        /* pub_key = g ^ priv_key mod p */
-        if (!BN_mod_exp(pub_key, dsa->params.g, prk, dsa->params.p, ctx)) {
-            BN_free(prk);
-            goto err;
-        }
-        /* We MUST free prk before any further use of priv_key */
-        BN_free(prk);
-    }
+    if (!dsa_generate_public_key(ctx, dsa, priv_key, pub_key))
+        goto err;
 
     dsa->priv_key = priv_key;
     dsa->pub_key = pub_key;