Diff: wolfcrypt/src/curve25519.c

Revision:

13:f67a6c6013ca

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wolfcrypt/src/curve25519.c	Tue Aug 22 10:48:22 2017 +0000
@@ -0,0 +1,463 @@
+/* curve25519.c
+ *
+ * Copyright (C) 2006-2016 wolfSSL Inc.
+ *
+ * This file is part of wolfSSL.
+ *
+ * wolfSSL is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * wolfSSL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
+ */
+
+
+ /* Based On Daniel J Bernstein's curve25519 Public Domain ref10 work. */
+
+
+#ifdef HAVE_CONFIG_H
+    #include <config.h>
+#endif
+
+#include <wolfssl/wolfcrypt/settings.h>
+
+#ifdef HAVE_CURVE25519
+
+#include <wolfssl/wolfcrypt/curve25519.h>
+#include <wolfssl/wolfcrypt/error-crypt.h>
+#ifdef NO_INLINE
+    #include <wolfssl/wolfcrypt/misc.h>
+#else
+    #define WOLFSSL_MISC_INCLUDED
+    #include <wolfcrypt/src/misc.c>
+#endif
+
+#if defined(FREESCALE_LTC_ECC)
+    #include <wolfssl/wolfcrypt/port/nxp/ksdk_port.h>
+#endif
+
+const curve25519_set_type curve25519_sets[] = {
+    {
+        32,
+        "CURVE25519",
+    }
+};
+
+int wc_curve25519_make_key(WC_RNG* rng, int keysize, curve25519_key* key)
+{
+#ifdef FREESCALE_LTC_ECC
+    const ECPoint* basepoint = wc_curve25519_GetBasePoint();
+#else
+    unsigned char basepoint[CURVE25519_KEYSIZE] = {9};
+#endif
+    int  ret;
+
+    if (key == NULL || rng == NULL)
+        return BAD_FUNC_ARG;
+
+    /* currently only a key size of 32 bytes is used */
+    if (keysize != CURVE25519_KEYSIZE)
+        return ECC_BAD_ARG_E;
+
+    /* random number for private key */
+    ret = wc_RNG_GenerateBlock(rng, key->k.point, keysize);
+    if (ret != 0)
+        return ret;
+
+    /* Clamp the private key */
+    key->k.point[0] &= 248;
+    key->k.point[CURVE25519_KEYSIZE-1] &= 63; /* same &=127 because |=64 after */
+    key->k.point[CURVE25519_KEYSIZE-1] |= 64;
+
+    /* compute public key */
+    #ifdef FREESCALE_LTC_ECC
+        ret = wc_curve25519(&key->p, key->k.point, basepoint, kLTC_Weierstrass); /* input basepoint on Weierstrass curve */
+    #else
+        ret = curve25519(key->p.point, key->k.point, basepoint);
+    #endif
+    if (ret != 0) {
+        ForceZero(key->k.point, keysize);
+        ForceZero(key->p.point, keysize);
+        return ret;
+    }
+
+    return ret;
+}
+
+#ifdef HAVE_CURVE25519_SHARED_SECRET
+
+int wc_curve25519_shared_secret(curve25519_key* private_key,
+                                curve25519_key* public_key,
+                                byte* out, word32* outlen)
+{
+    return wc_curve25519_shared_secret_ex(private_key, public_key,
+                                          out, outlen, EC25519_BIG_ENDIAN);
+}
+
+int wc_curve25519_shared_secret_ex(curve25519_key* private_key,
+                                   curve25519_key* public_key,
+                                   byte* out, word32* outlen, int endian)
+{
+    #ifdef FREESCALE_LTC_ECC
+        ECPoint o = {{0}};
+    #else
+        unsigned char o[CURVE25519_KEYSIZE];
+    #endif
+    int ret = 0;
+
+    /* sanity check */
+    if (private_key == NULL || public_key == NULL ||
+        out == NULL || outlen == NULL || *outlen < CURVE25519_KEYSIZE)
+        return BAD_FUNC_ARG;
+
+    /* avoid implementation fingerprinting */
+    if (public_key->p.point[CURVE25519_KEYSIZE-1] > 0x7F)
+        return ECC_BAD_ARG_E;
+
+    #ifdef FREESCALE_LTC_ECC
+        ret = wc_curve25519(&o, private_key->k.point, &public_key->p, kLTC_Curve25519 /* input point P on Curve25519 */);
+    #else
+        ret = curve25519(o, private_key->k.point, public_key->p.point);
+    #endif
+    if (ret != 0) {
+        #ifdef FREESCALE_LTC_ECC
+            ForceZero(o.point, CURVE25519_KEYSIZE);
+            ForceZero(o.pointY, CURVE25519_KEYSIZE);
+        #else
+            ForceZero(o, CURVE25519_KEYSIZE);
+        #endif
+        return ret;
+    }
+
+    if (endian == EC25519_BIG_ENDIAN) {
+        int i;
+        /* put shared secret key in Big Endian format */
+        for (i = 0; i < CURVE25519_KEYSIZE; i++)
+            #ifdef FREESCALE_LTC_ECC
+                out[i] = o.point[CURVE25519_KEYSIZE - i -1];
+            #else
+                out[i] = o[CURVE25519_KEYSIZE - i -1];
+            #endif
+    }
+    else /* put shared secret key in Little Endian format */
+        #ifdef FREESCALE_LTC_ECC
+            XMEMCPY(out, o.point, CURVE25519_KEYSIZE);
+        #else
+            XMEMCPY(out, o, CURVE25519_KEYSIZE);
+        #endif
+
+    *outlen = CURVE25519_KEYSIZE;
+
+    #ifdef FREESCALE_LTC_ECC
+        ForceZero(o.point, CURVE25519_KEYSIZE);
+        ForceZero(o.pointY, CURVE25519_KEYSIZE);
+    #else
+        ForceZero(o, CURVE25519_KEYSIZE);
+    #endif
+
+    return ret;
+}
+
+#endif /* HAVE_CURVE25519_SHARED_SECRET */
+
+#ifdef HAVE_CURVE25519_KEY_EXPORT
+
+/* export curve25519 public key (Big endian)
+ * return 0 on success */
+int wc_curve25519_export_public(curve25519_key* key, byte* out, word32* outLen)
+{
+    return wc_curve25519_export_public_ex(key, out, outLen, EC25519_BIG_ENDIAN);
+}
+
+/* export curve25519 public key (Big or Little endian)
+ * return 0 on success */
+int wc_curve25519_export_public_ex(curve25519_key* key, byte* out,
+                                   word32* outLen, int endian)
+{
+    word32 keySz;
+
+    if (key == NULL || out == NULL || outLen == NULL)
+        return BAD_FUNC_ARG;
+
+    /* check size of outgoing key */
+    keySz  = wc_curve25519_size(key);
+
+    /* check and set outgoing key size */
+    if (*outLen < keySz) {
+        *outLen = keySz;
+        return ECC_BAD_ARG_E;
+    }
+    *outLen = keySz;
+
+    if (endian == EC25519_BIG_ENDIAN) {
+        int i;
+
+        /* read keys in Big Endian format */
+        for (i = 0; i < CURVE25519_KEYSIZE; i++)
+            out[i] = key->p.point[CURVE25519_KEYSIZE - i - 1];
+    }
+    else
+        XMEMCPY(out, key->p.point, keySz);
+
+    return 0;
+}
+
+#endif /* HAVE_CURVE25519_KEY_EXPORT */
+
+#ifdef HAVE_CURVE25519_KEY_IMPORT
+
+/* import curve25519 public key (Big endian)
+ *  return 0 on success */
+int wc_curve25519_import_public(const byte* in, word32 inLen,
+                                curve25519_key* key)
+{
+    return wc_curve25519_import_public_ex(in, inLen, key, EC25519_BIG_ENDIAN);
+}
+
+/* import curve25519 public key (Big or Little endian)
+ * return 0 on success */
+int wc_curve25519_import_public_ex(const byte* in, word32 inLen,
+                                curve25519_key* key, int endian)
+{
+    word32 keySz;
+
+    /* sanity check */
+    if (key == NULL || in == NULL)
+        return BAD_FUNC_ARG;
+
+    /* check size of incoming keys */
+    keySz = wc_curve25519_size(key);
+    if (inLen != keySz)
+       return ECC_BAD_ARG_E;
+
+    if (endian == EC25519_BIG_ENDIAN) {
+        int i;
+
+        /* read keys in Big Endian format */
+        for (i = 0; i < CURVE25519_KEYSIZE; i++)
+            key->p.point[i] = in[CURVE25519_KEYSIZE - i - 1];
+    }
+    else
+        XMEMCPY(key->p.point, in, inLen);
+
+    key->dp = &curve25519_sets[0];
+
+    /* LTC needs also Y coordinate - let's compute it */
+    #ifdef FREESCALE_LTC_ECC
+        ltc_pkha_ecc_point_t ltcPoint;
+        ltcPoint.X = &key->p.point[0];
+        ltcPoint.Y = &key->p.pointY[0];
+        LTC_PKHA_Curve25519ComputeY(&ltcPoint);
+    #endif
+
+    return 0;
+}
+
+#endif /* HAVE_CURVE25519_KEY_IMPORT */
+
+
+#ifdef HAVE_CURVE25519_KEY_EXPORT
+
+/* export curve25519 private key only raw (Big endian)
+ * outLen is in/out size
+ * return 0 on success */
+int wc_curve25519_export_private_raw(curve25519_key* key, byte* out,
+                                     word32* outLen)
+{
+    return wc_curve25519_export_private_raw_ex(key, out, outLen,
+                                               EC25519_BIG_ENDIAN);
+}
+
+/* export curve25519 private key only raw (Big or Little endian)
+ * outLen is in/out size
+ * return 0 on success */
+int wc_curve25519_export_private_raw_ex(curve25519_key* key, byte* out,
+                                        word32* outLen, int endian)
+{
+    word32 keySz;
+
+    /* sanity check */
+    if (key == NULL || out == NULL || outLen == NULL)
+        return BAD_FUNC_ARG;
+
+    /* check size of outgoing buffer */
+    keySz = wc_curve25519_size(key);
+    if (*outLen < keySz) {
+        *outLen = keySz;
+        return ECC_BAD_ARG_E;
+    }
+    *outLen = keySz;
+
+    if (endian == EC25519_BIG_ENDIAN) {
+        int i;
+
+        /* put the key in Big Endian format */
+        for (i = 0; i < CURVE25519_KEYSIZE; i++)
+            out[i] = key->k.point[CURVE25519_KEYSIZE - i - 1];
+    }
+    else
+        XMEMCPY(out, key->k.point, keySz);
+
+    return 0;
+}
+
+/* curve25519 key pair export (Big or Little endian)
+ * return 0 on success */
+int wc_curve25519_export_key_raw(curve25519_key* key,
+                                 byte* priv, word32 *privSz,
+                                 byte* pub, word32 *pubSz)
+{
+    return wc_curve25519_export_key_raw_ex(key, priv, privSz,
+                                           pub, pubSz, EC25519_BIG_ENDIAN);
+}
+
+/* curve25519 key pair export (Big or Little endian)
+ * return 0 on success */
+int wc_curve25519_export_key_raw_ex(curve25519_key* key,
+                                    byte* priv, word32 *privSz,
+                                    byte* pub, word32 *pubSz,
+                                    int endian)
+{
+    int ret;
+
+    /* export private part */
+    ret = wc_curve25519_export_private_raw_ex(key, priv, privSz, endian);
+    if (ret != 0)
+        return ret;
+
+    /* export public part */
+    return wc_curve25519_export_public_ex(key, pub, pubSz, endian);
+}
+
+#endif /* HAVE_CURVE25519_KEY_EXPORT */
+
+#ifdef HAVE_CURVE25519_KEY_IMPORT
+
+/* curve25519 private key import (Big endian)
+ * Public key to match private key needs to be imported too
+ * return 0 on success */
+int wc_curve25519_import_private_raw(const byte* priv, word32 privSz,
+                                     const byte* pub, word32 pubSz,
+                                     curve25519_key* key)
+{
+    return wc_curve25519_import_private_raw_ex(priv, privSz, pub, pubSz,
+                                               key, EC25519_BIG_ENDIAN);
+}
+
+/* curve25519 private key import (Big or Little endian)
+ * Public key to match private key needs to be imported too
+ * return 0 on success */
+int wc_curve25519_import_private_raw_ex(const byte* priv, word32 privSz,
+                                        const byte* pub, word32 pubSz,
+                                        curve25519_key* key, int endian)
+{
+    int ret;
+
+    /* import private part */
+    ret = wc_curve25519_import_private_ex(priv, privSz, key, endian);
+    if (ret != 0)
+        return ret;
+
+    /* import public part */
+    return wc_curve25519_import_public_ex(pub, pubSz, key, endian);
+}
+
+/* curve25519 private key import only. (Big endian)
+ * return 0 on success */
+int wc_curve25519_import_private(const byte* priv, word32 privSz,
+                                 curve25519_key* key)
+{
+    return wc_curve25519_import_private_ex(priv, privSz,
+                                           key, EC25519_BIG_ENDIAN);
+}
+
+/* curve25519 private key import only. (Big or Little endian)
+ * return 0 on success */
+int wc_curve25519_import_private_ex(const byte* priv, word32 privSz,
+                                    curve25519_key* key, int endian)
+{
+    /* sanity check */
+    if (key == NULL || priv == NULL)
+        return BAD_FUNC_ARG;
+
+    /* check size of incoming keys */
+    if ((int)privSz != wc_curve25519_size(key))
+        return ECC_BAD_ARG_E;
+
+    if (endian == EC25519_BIG_ENDIAN) {
+        int i;
+
+        /* read the key in Big Endian format */
+        for (i = 0; i < CURVE25519_KEYSIZE; i++)
+            key->k.point[i] = priv[CURVE25519_KEYSIZE - i - 1];
+    }
+    else
+        XMEMCPY(key->k.point, priv, privSz);
+
+    key->dp = &curve25519_sets[0];
+
+    /* Clamp the key */
+    key->k.point[0] &= 248;
+    key->k.point[privSz-1] &= 63; /* same &=127 because |=64 after */
+    key->k.point[privSz-1] |= 64;
+
+    return 0;
+}
+
+#endif /* HAVE_CURVE25519_KEY_IMPORT */
+
+
+int wc_curve25519_init(curve25519_key* key)
+{
+    if (key == NULL)
+       return BAD_FUNC_ARG;
+
+    /* currently the format for curve25519 */
+    key->dp = &curve25519_sets[0];
+
+    XMEMSET(key->k.point, 0, key->dp->size);
+    XMEMSET(key->p.point, 0, key->dp->size);
+    #ifdef FREESCALE_LTC_ECC
+        XMEMSET(key->k.pointY, 0, key->dp->size);
+        XMEMSET(key->p.pointY, 0, key->dp->size);
+    #endif
+    return 0;
+}
+
+
+/* Clean the memory of a key */
+void wc_curve25519_free(curve25519_key* key)
+{
+   if (key == NULL)
+       return;
+
+   key->dp = NULL;
+   ForceZero(key->p.point, sizeof(key->p.point));
+   ForceZero(key->k.point, sizeof(key->k.point));
+   #ifdef FREESCALE_LTC_ECC
+       ForceZero(key->p.point, sizeof(key->p.pointY));
+       ForceZero(key->k.point, sizeof(key->k.pointY));
+   #endif
+}
+
+
+/* get key size */
+int wc_curve25519_size(curve25519_key* key)
+{
+    if (key == NULL)
+        return 0;
+
+    return key->dp->size;
+}
+
+#endif /*HAVE_CURVE25519*/
+
+