Reorganize local header files

[thirdparty/openssl.git] / crypto / dh / dh_key.c

diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c
index ce0194860242cd5bff20af1f5b18fc7595700a27..a8a9dbe764b2fcf7adc1472a77fa1885387f26b0 100644 (file)
--- a/crypto/dh/dh_key.c
+++ b/crypto/dh/dh_key.c
@@ -1,7 +1,7 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved.
  *
- * Licensed under the OpenSSL license (the "License").  You may not use
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
@@ -9,8 +9,8 @@
 
 #include <stdio.h>
 #include "internal/cryptlib.h"
-#include "dh_locl.h"
-#include "internal/bn_int.h"
+#include "dh_local.h"
+#include "crypto/bn.h"
 
 static int generate_key(DH *dh);
 static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh);
@@ -78,10 +78,20 @@ static int generate_key(DH *dh)
     int ok = 0;
     int generate_new_key = 0;
     unsigned l;
-    BN_CTX *ctx;
+    BN_CTX *ctx = NULL;
     BN_MONT_CTX *mont = NULL;
     BIGNUM *pub_key = NULL, *priv_key = NULL;
 
+    if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) {
+        DHerr(DH_F_GENERATE_KEY, DH_R_MODULUS_TOO_LARGE);
+        return 0;
+    }
+
+    if (BN_num_bits(dh->p) < DH_MIN_MODULUS_BITS) {
+        DHerr(DH_F_GENERATE_KEY, DH_R_MODULUS_TOO_SMALL);
+        return 0;
+    }
+
     ctx = BN_CTX_new();
     if (ctx == NULL)
         goto err;
@@ -120,6 +130,15 @@ static int generate_key(DH *dh)
             l = dh->length ? dh->length : BN_num_bits(dh->p) - 1;
             if (!BN_priv_rand(priv_key, l, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY))
                 goto err;
+            /*
+             * We handle just one known case where g is a quadratic non-residue:
+             * for g = 2: p % 8 == 3
+             */
+            if (BN_is_word(dh->g, DH_GENERATOR_2) && !BN_is_bit_set(dh->p, 2)) {
+                /* clear bit 0, since it won't be a secret anyway */
+                if (!BN_clear_bit(priv_key, 0))
+                    goto err;
+            }
         }
     }
 
@@ -131,15 +150,16 @@ static int generate_key(DH *dh)
         BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
 
         if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, prk, dh->p, ctx, mont)) {
-            BN_free(prk);
+            BN_clear_free(prk);
             goto err;
         }
         /* We MUST free prk before any further use of priv_key */
-        BN_free(prk);
+        BN_clear_free(prk);
     }
 
     dh->pub_key = pub_key;
     dh->priv_key = priv_key;
+    dh->dirty_cnt++;
     ok = 1;
  err:
     if (ok != 1)
@@ -150,7 +170,7 @@ static int generate_key(DH *dh)
     if (priv_key != dh->priv_key)
         BN_free(priv_key);
     BN_CTX_free(ctx);
-    return (ok);
+    return ok;
 }
 
 static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
@@ -166,6 +186,11 @@ static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
         goto err;
     }
 
+    if (BN_num_bits(dh->p) < DH_MIN_MODULUS_BITS) {
+        DHerr(DH_F_COMPUTE_KEY, DH_R_MODULUS_TOO_SMALL);
+        return 0;
+    }
+
     ctx = BN_CTX_new();
     if (ctx == NULL)
         goto err;
@@ -200,11 +225,9 @@ static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
 
     ret = BN_bn2bin(tmp, key);
  err:
-    if (ctx != NULL) {
-        BN_CTX_end(ctx);
-        BN_CTX_free(ctx);
-    }
-    return (ret);
+    BN_CTX_end(ctx);
+    BN_CTX_free(ctx);
+    return ret;
 }
 
 static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
@@ -217,11 +240,74 @@ static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
 static int dh_init(DH *dh)
 {
     dh->flags |= DH_FLAG_CACHE_MONT_P;
-    return (1);
+    return 1;
 }
 
 static int dh_finish(DH *dh)
 {
     BN_MONT_CTX_free(dh->method_mont_p);
-    return (1);
+    return 1;
+}
+
+int dh_buf2key(DH *dh, const unsigned char *buf, size_t len)
+{
+    int err_reason = DH_R_BN_ERROR;
+    BIGNUM *pubkey = NULL;
+    const BIGNUM *p;
+    size_t p_size;
+
+    if ((pubkey = BN_bin2bn(buf, len, NULL)) == NULL)
+        goto err;
+    DH_get0_pqg(dh, &p, NULL, NULL);
+    if (p == NULL || (p_size = BN_num_bytes(p)) == 0) {
+        err_reason = DH_R_NO_PARAMETERS_SET;
+        goto err;
+    }
+    /*
+     * As per Section 4.2.8.1 of RFC 8446 fail if DHE's
+     * public key is of size not equal to size of p
+     */
+    if (BN_is_zero(pubkey) || p_size != len) {
+        err_reason = DH_R_INVALID_PUBKEY;
+        goto err;
+    }
+    if (DH_set0_key(dh, pubkey, NULL) != 1)
+        goto err;
+    return 1;
+err:
+    DHerr(DH_F_DH_BUF2KEY, err_reason);
+    BN_free(pubkey);
+    return 0;
+}
+
+size_t dh_key2buf(const DH *dh, unsigned char **pbuf_out)
+{
+    const BIGNUM *pubkey;
+    unsigned char *pbuf;
+    const BIGNUM *p;
+    int p_size;
+
+    DH_get0_pqg(dh, &p, NULL, NULL);
+    DH_get0_key(dh, &pubkey, NULL);
+    if (p == NULL || pubkey == NULL
+            || (p_size = BN_num_bytes(p)) == 0
+            || BN_num_bytes(pubkey) == 0) {
+        DHerr(DH_F_DH_KEY2BUF, DH_R_INVALID_PUBKEY);
+        return 0;
+    }
+    if ((pbuf = OPENSSL_malloc(p_size)) == NULL) {
+        DHerr(DH_F_DH_KEY2BUF, ERR_R_MALLOC_FAILURE);
+        return 0;
+    }
+    /*
+     * As per Section 4.2.8.1 of RFC 8446 left pad public
+     * key with zeros to the size of p
+     */
+    if (BN_bn2binpad(pubkey, pbuf, p_size) < 0) {
+        OPENSSL_free(pbuf);
+        DHerr(DH_F_DH_KEY2BUF, DH_R_BN_ERROR);
+        return 0;
+    }
+    *pbuf_out = pbuf;
+    return p_size;
 }