Make the DSA structure opaque

Move the dsa_st structure out of the public header file. Add some accessor
functions to enable access to the internal fields, and update all internal
usage to use the new functions.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Stephen Henson <steve@openssl.org>

9 files changed, 140 insertions, 25 deletions

diff --git a/crypto/dsa/dsa_ameth.c b/crypto/dsa/dsa_ameth.c
index f0f28bdf2a..54cdb3dae0 100644
--- a/crypto/dsa/dsa_ameth.c
+++ b/crypto/dsa/dsa_ameth.c
@@ -60,7 +60,7 @@
 #include "internal/cryptlib.h"
 #include <openssl/x509.h>
 #include <openssl/asn1.h>
-#include <openssl/dsa.h>
+#include "dsa_locl.h"
 #include <openssl/bn.h>
 #include <openssl/cms.h>
 #include "internal/asn1_int.h"
diff --git a/crypto/dsa/dsa_asn1.c b/crypto/dsa/dsa_asn1.c
index c338b5f3a8..1468fb1e66 100644
--- a/crypto/dsa/dsa_asn1.c
+++ b/crypto/dsa/dsa_asn1.c
@@ -58,7 +58,7 @@
 
 #include <stdio.h>
 #include "internal/cryptlib.h"
-#include <openssl/dsa.h>
+#include "dsa_locl.h"
 #include <openssl/asn1.h>
 #include <openssl/asn1t.h>
 #include <openssl/rand.h>
diff --git a/crypto/dsa/dsa_key.c b/crypto/dsa/dsa_key.c
index 831c2b1d9b..441588498e 100644
--- a/crypto/dsa/dsa_key.c
+++ b/crypto/dsa/dsa_key.c
@@ -59,7 +59,7 @@
 #include <time.h>
 #include "internal/cryptlib.h"
 #include <openssl/bn.h>
-#include <openssl/dsa.h>
+#include "dsa_locl.h"
 #include <openssl/rand.h>
 
 static int dsa_builtin_keygen(DSA *dsa);
diff --git a/crypto/dsa/dsa_lib.c b/crypto/dsa/dsa_lib.c
index fa8330fd84..08226181f9 100644
--- a/crypto/dsa/dsa_lib.c
+++ b/crypto/dsa/dsa_lib.c
@@ -60,7 +60,7 @@
 #include <stdio.h>
 #include "internal/cryptlib.h"
 #include <openssl/bn.h>
-#include <openssl/dsa.h>
+#include "dsa_locl.h"
 #include <openssl/asn1.h>
 #include <openssl/engine.h>
 #include <openssl/dh.h>
@@ -280,3 +280,76 @@ DH *DSA_dup_DH(const DSA *r)
     return NULL;
 }
 #endif
+
+BIGNUM *DSA_get0_p(const DSA *d)
+{
+    return d->p;
+}
+
+BIGNUM *DSA_get0_q(const DSA *d)
+{
+    return d->q;
+}
+
+BIGNUM *DSA_get0_g(const DSA *d)
+{
+    return d->g;
+}
+
+int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
+{
+    if (p == NULL || q == NULL || g == NULL)
+        return 0;
+    BN_free(d->p);
+    BN_free(d->q);
+    BN_free(d->g);
+    d->p = p;
+    d->q = q;
+    d->g = g;
+
+    return 1;
+}
+
+BIGNUM *DSA_get0_priv_key(const DSA *d)
+{
+    return d->priv_key;
+}
+
+BIGNUM *DSA_get0_pub_key(const DSA *d)
+{
+    return d->pub_key;
+}
+
+void DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key)
+{
+    /* Note that it is valid for priv_key to be NULL */
+    if (pub_key == NULL)
+        return 0;
+
+    BN_free(d->pub_key);
+    BN_free(d->priv_key);
+    d->pub_key = pub_key;
+    d->priv_key = priv_key;
+
+    return 1;
+}
+
+void DSA_clear_flags(DSA *d, int flags)
+{
+    d->flags &= ~flags;
+}
+
+int DSA_test_flags(const DSA *d, int flags)
+{
+    return d->flags & flags;
+}
+
+void DSA_set_flags(DSA *d, int flags)
+{
+    d->flags |= flags;
+}
+
+ENGINE *DSA_get0_engine(DSA *d)
+{
+    return d->engine;
+}
diff --git a/crypto/dsa/dsa_locl.h b/crypto/dsa/dsa_locl.h
index 6182495848..9b25634ae3 100644
--- a/crypto/dsa/dsa_locl.h
+++ b/crypto/dsa/dsa_locl.h
@@ -54,6 +54,29 @@
 
 #include <openssl/dsa.h>
 
+struct dsa_st {
+    /*
+     * This first variable is used to pick up errors where a DSA is passed
+     * instead of of a EVP_PKEY
+     */
+    int pad;
+    long version;
+    BIGNUM *p;
+    BIGNUM *q;                  /* == 20 */
+    BIGNUM *g;
+    BIGNUM *pub_key;            /* y public key */
+    BIGNUM *priv_key;           /* x private key */
+    int flags;
+    /* Normally used to cache montgomery values */
+    BN_MONT_CTX *method_mont_p;
+    int references;
+    CRYPTO_EX_DATA ex_data;
+    const DSA_METHOD *meth;
+    /* functional reference if 'meth' is ENGINE-provided */
+    ENGINE *engine;
+    CRYPTO_RWLOCK *lock;
+};
+
 int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
                          const EVP_MD *evpmd, const unsigned char *seed_in,
                          size_t seed_len, unsigned char *seed_out,
diff --git a/crypto/dsa/dsa_ossl.c b/crypto/dsa/dsa_ossl.c
index 31a6d53c9a..92855537b8 100644
--- a/crypto/dsa/dsa_ossl.c
+++ b/crypto/dsa/dsa_ossl.c
@@ -61,7 +61,7 @@
 #include "internal/cryptlib.h"
 #include <openssl/bn.h>
 #include <openssl/sha.h>
-#include <openssl/dsa.h>
+#include "dsa_locl.h"
 #include <openssl/rand.h>
 #include <openssl/asn1.h>
 
diff --git a/crypto/dsa/dsa_sign.c b/crypto/dsa/dsa_sign.c
index ca712cf201..b9dcd5b28d 100644
--- a/crypto/dsa/dsa_sign.c
+++ b/crypto/dsa/dsa_sign.c
@@ -58,7 +58,7 @@
 /* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
 
 #include "internal/cryptlib.h"
-#include <openssl/dsa.h>
+#include "dsa_locl.h"
 #include <openssl/rand.h>
 #include <openssl/bn.h>
 
diff --git a/crypto/dsa/dsa_vrf.c b/crypto/dsa/dsa_vrf.c
index 6724b7545f..6ce9968eaf 100644
--- a/crypto/dsa/dsa_vrf.c
+++ b/crypto/dsa/dsa_vrf.c
@@ -58,7 +58,7 @@
 /* Original version from Steven Schoch <schoch@sheba.arc.nasa.gov> */
 
 #include "internal/cryptlib.h"
-#include <openssl/dsa.h>
+#include "dsa_locl.h"
 
 int DSA_do_verify(const unsigned char *dgst, int dgst_len, DSA_SIG *sig,
                   DSA *dsa)
diff --git a/crypto/pem/pvkfmt.c b/crypto/pem/pvkfmt.c
index 117d2b794d..ac4b84c59e 100644
--- a/crypto/pem/pvkfmt.c
+++ b/crypto/pem/pvkfmt.c
@@ -289,34 +289,48 @@ static EVP_PKEY *b2i_dss(const unsigned char **in,
     DSA *dsa = NULL;
     BN_CTX *ctx = NULL;
     unsigned int nbyte;
+    BIGNUM *pbn = NULL, *qbn = NULL, *gbn = NULL, *priv_key = NULL;
+    BIGNUM *pub_key = NULL;
+
     nbyte = (bitlen + 7) >> 3;
 
     dsa = DSA_new();
     ret = EVP_PKEY_new();
     if (dsa == NULL || ret == NULL)
         goto memerr;
-    if (!read_lebn(&p, nbyte, &dsa->p))
+    if (!read_lebn(&p, nbyte, &pbn))
         goto memerr;
-    if (!read_lebn(&p, 20, &dsa->q))
+
+    if (!read_lebn(&p, 20, &qbn))
         goto memerr;
-    if (!read_lebn(&p, nbyte, &dsa->g))
+
+    if (!read_lebn(&p, nbyte, &gbn))
         goto memerr;
+
     if (ispub) {
-        if (!read_lebn(&p, nbyte, &dsa->pub_key))
+        if (!read_lebn(&p, nbyte, &pub_key))
             goto memerr;
     } else {
-        if (!read_lebn(&p, 20, &dsa->priv_key))
+        if (!read_lebn(&p, 20, &priv_key))
             goto memerr;
+
         /* Calculate public key */
-        if ((dsa->pub_key = BN_new()) == NULL)
+        pub_key = BN_new();
+        if (pub_key == NULL)
             goto memerr;
         if ((ctx = BN_CTX_new()) == NULL)
             goto memerr;
 
-        if (!BN_mod_exp(dsa->pub_key, dsa->g, dsa->priv_key, dsa->p, ctx))
+        if (!BN_mod_exp(pub_key, gbn, priv_key, pbn, ctx))
             goto memerr;
+
         BN_CTX_free(ctx);
     }
+    if (!DSA_set0_pqg(dsa, pbn, qbn, gbn))
+        goto memerr;
+    pbn = qbn = gbn = NULL;
+    if (!DSA_set0_key(dsa, pub_key, priv_key))
+        goto memerr;
 
     EVP_PKEY_set1_DSA(ret, dsa);
     DSA_free(dsa);
@@ -326,6 +340,11 @@ static EVP_PKEY *b2i_dss(const unsigned char **in,
  memerr:
     PEMerr(PEM_F_B2I_DSS, ERR_R_MALLOC_FAILURE);
     DSA_free(dsa);
+    BN_free(pbn);
+    BN_free(qbn);
+    BN_free(gbn);
+    BN_free(pub_key);
+    BN_free(priv_key);
     EVP_PKEY_free(ret);
     BN_CTX_free(ctx);
     return NULL;
@@ -484,16 +503,16 @@ static int do_i2b_bio(BIO *out, EVP_PKEY *pk, int ispub)
 static int check_bitlen_dsa(DSA *dsa, int ispub, unsigned int *pmagic)
 {
     int bitlen;
-    bitlen = BN_num_bits(dsa->p);
-    if ((bitlen & 7) || (BN_num_bits(dsa->q) != 160)
-        || (BN_num_bits(dsa->g) > bitlen))
+    bitlen = BN_num_bits(DSA_get0_p(dsa));
+    if ((bitlen & 7) || (BN_num_bits(DSA_get0_q(dsa)) != 160)
+        || (BN_num_bits(DSA_get0_g(dsa)) > bitlen))
         goto badkey;
     if (ispub) {
-        if (BN_num_bits(dsa->pub_key) > bitlen)
+        if (BN_num_bits(DSA_get0_pub_key(dsa)) > bitlen)
             goto badkey;
         *pmagic = MS_DSS1MAGIC;
     } else {
-        if (BN_num_bits(dsa->priv_key) > 160)
+        if (BN_num_bits(DSA_get0_priv_key(dsa)) > 160)
             goto badkey;
         *pmagic = MS_DSS2MAGIC;
     }
@@ -555,14 +574,14 @@ static void write_rsa(unsigned char **out, RSA *rsa, int ispub)
 static void write_dsa(unsigned char **out, DSA *dsa, int ispub)
 {
     int nbyte;
-    nbyte = BN_num_bytes(dsa->p);
-    write_lebn(out, dsa->p, nbyte);
-    write_lebn(out, dsa->q, 20);
-    write_lebn(out, dsa->g, nbyte);
+    nbyte = BN_num_bytes(DSA_get0_p(dsa));
+    write_lebn(out, DSA_get0_p(dsa), nbyte);
+    write_lebn(out, DSA_get0_q(dsa), 20);
+    write_lebn(out, DSA_get0_g(dsa), nbyte);
     if (ispub)
-        write_lebn(out, dsa->pub_key, nbyte);
+        write_lebn(out, DSA_get0_pub_key(dsa), nbyte);
     else
-        write_lebn(out, dsa->priv_key, 20);
+        write_lebn(out, DSA_get0_priv_key(dsa), 20);
     /* Set "invalid" for seed structure values */
     memset(*out, 0xff, 24);
     *out += 24;