Fix users of KDFs to use params not ctls

[openssl.git] / crypto / ec / ecdh_kdf.c

diff --git a/crypto/ec/ecdh_kdf.c b/crypto/ec/ecdh_kdf.c
index d686f9d897df1afd4af72de4fd2fe0314b40929a..55e676d20a437bd097c1d646516cef910fbc0043 100644 (file)
--- a/crypto/ec/ecdh_kdf.c
+++ b/crypto/ec/ecdh_kdf.c
@@ -1,77 +1,54 @@
 /*
- * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2015-2019 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
  */
 
 #include <string.h>
+#include <openssl/core_names.h>
 #include <openssl/ec.h>
 #include <openssl/evp.h>
+#include <openssl/kdf.h>
 #include "ec_lcl.h"
 
 /* Key derivation function from X9.63/SECG */
-/* Way more than we will ever need */
-#define ECDH_KDF_MAX    (1 << 30)
-
 int ecdh_KDF_X9_63(unsigned char *out, size_t outlen,
                    const unsigned char *Z, size_t Zlen,
                    const unsigned char *sinfo, size_t sinfolen,
                    const EVP_MD *md)
 {
-    EVP_MD_CTX *mctx = NULL;
-    int rv = 0;
-    unsigned int i;
-    size_t mdlen;
-    unsigned char ctr[4];
-    if (sinfolen > ECDH_KDF_MAX || outlen > ECDH_KDF_MAX
-        || Zlen > ECDH_KDF_MAX)
-        return 0;
-    mctx = EVP_MD_CTX_new();
-    if (mctx == NULL)
-        return 0;
-    mdlen = EVP_MD_size(md);
-    for (i = 1;; i++) {
-        unsigned char mtmp[EVP_MAX_MD_SIZE];
-        if (!EVP_DigestInit_ex(mctx, md, NULL))
-            goto err;
-        ctr[3] = i & 0xFF;
-        ctr[2] = (i >> 8) & 0xFF;
-        ctr[1] = (i >> 16) & 0xFF;
-        ctr[0] = (i >> 24) & 0xFF;
-        if (!EVP_DigestUpdate(mctx, Z, Zlen))
-            goto err;
-        if (!EVP_DigestUpdate(mctx, ctr, sizeof(ctr)))
-            goto err;
-        if (!EVP_DigestUpdate(mctx, sinfo, sinfolen))
-            goto err;
-        if (outlen >= mdlen) {
-            if (!EVP_DigestFinal(mctx, out, NULL))
-                goto err;
-            outlen -= mdlen;
-            if (outlen == 0)
-                break;
-            out += mdlen;
-        } else {
-            if (!EVP_DigestFinal(mctx, mtmp, NULL))
-                goto err;
-            memcpy(out, mtmp, outlen);
-            OPENSSL_cleanse(mtmp, mdlen);
-            break;
-        }
+    int ret = 0;
+    EVP_KDF_CTX *kctx = NULL;
+    OSSL_PARAM params[4], *p = params;
+    const char *mdname = EVP_MD_name(md);
+    EVP_KDF *kdf = EVP_KDF_fetch(NULL, SN_x963kdf, NULL);
+
+    if ((kctx = EVP_KDF_CTX_new(kdf)) != NULL) {
+        *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
+                                                (char *)mdname,
+                                                strlen(mdname) + 1);
+        *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
+                                                 (void *)Z, Zlen);
+        *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_INFO,
+                                                 (void *)sinfo, sinfolen);
+        *p = OSSL_PARAM_construct_end();
+
+        ret = EVP_KDF_CTX_set_params(kctx, params) > 0
+            && EVP_KDF_derive(kctx, out, outlen) > 0;
+        EVP_KDF_CTX_free(kctx);
     }
-    rv = 1;
- err:
-    EVP_MD_CTX_free(mctx);
-    return rv;
+    EVP_KDF_free(kdf);
+    return ret;
 }
 
 /*-
  * The old name for ecdh_KDF_X9_63
  * Retained for ABI compatibility
  */
+#if !OPENSSL_API_3
 int ECDH_KDF_X9_62(unsigned char *out, size_t outlen,
                    const unsigned char *Z, size_t Zlen,
                    const unsigned char *sinfo, size_t sinfolen,
@@ -79,3 +56,4 @@ int ECDH_KDF_X9_62(unsigned char *out, size_t outlen,
 {
     return ecdh_KDF_X9_63(out, outlen, Z, Zlen, sinfo, sinfolen, md);
 }
+#endif