Diff: wolfcrypt/src/ed25519.c

Revision:

13:f67a6c6013ca

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wolfcrypt/src/ed25519.c	Tue Aug 22 10:48:22 2017 +0000
@@ -0,0 +1,577 @@
+/* ed25519.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 ed25519 Public Domain ref10 work. */
+
+#ifdef HAVE_CONFIG_H
+    #include <config.h>
+#endif
+
+/* in case user set HAVE_ED25519 there */
+#include <wolfssl/wolfcrypt/settings.h>
+
+#ifdef HAVE_ED25519
+
+#include <wolfssl/wolfcrypt/ed25519.h>
+#include <wolfssl/wolfcrypt/error-crypt.h>
+#include <wolfssl/wolfcrypt/hash.h>
+#ifdef NO_INLINE
+    #include <wolfssl/wolfcrypt/misc.h>
+#else
+    #define WOLFSSL_MISC_INCLUDED
+    #include <wolfcrypt/src/misc.c>
+#endif
+
+#ifdef FREESCALE_LTC_ECC
+    #include <wolfssl/wolfcrypt/port/nxp/ksdk_port.h>
+#endif
+
+/* generate an ed25519 key pair.
+ * returns 0 on success
+ */
+int wc_ed25519_make_key(WC_RNG* rng, int keySz, ed25519_key* key)
+{
+    byte  az[ED25519_PRV_KEY_SIZE];
+    int   ret;
+#if !defined(FREESCALE_LTC_ECC)
+    ge_p3 A;
+#endif
+
+    if (rng == NULL || key == NULL)
+        return BAD_FUNC_ARG;
+
+    /* ed25519 has 32 byte key sizes */
+    if (keySz != ED25519_KEY_SIZE)
+        return BAD_FUNC_ARG;
+
+    ret  = wc_RNG_GenerateBlock(rng, key->k, ED25519_KEY_SIZE);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Hash(key->k, ED25519_KEY_SIZE, az);
+    if (ret != 0) {
+        ForceZero(key->k, ED25519_KEY_SIZE);
+        return ret;
+    }
+
+    /* apply clamp */
+    az[0]  &= 248;
+    az[31] &= 63; /* same than az[31] &= 127 because of az[31] |= 64 */
+    az[31] |= 64;
+
+#ifdef FREESCALE_LTC_ECC
+    ltc_pkha_ecc_point_t publicKey = {0};
+    publicKey.X = key->pointX;
+    publicKey.Y = key->pointY;
+    LTC_PKHA_Ed25519_PointMul(LTC_PKHA_Ed25519_BasePoint(), az, ED25519_KEY_SIZE, &publicKey, kLTC_Ed25519 /* result on Ed25519 */);
+    LTC_PKHA_Ed25519_Compress(&publicKey, key->p);
+#else
+    ge_scalarmult_base(&A, az);
+    ge_p3_tobytes(key->p, &A);
+#endif
+    /* put public key after private key, on the same buffer */
+    XMEMMOVE(key->k + ED25519_KEY_SIZE, key->p, ED25519_PUB_KEY_SIZE);
+
+    return ret;
+}
+
+
+#ifdef HAVE_ED25519_SIGN
+/*
+    in     contains the message to sign
+    inlen  is the length of the message to sign
+    out    is the buffer to write the signature
+    outLen [in/out] input size of out buf
+                     output gets set as the final length of out
+    key    is the ed25519 key to use when signing
+    return 0 on success
+ */
+int wc_ed25519_sign_msg(const byte* in, word32 inlen, byte* out,
+                        word32 *outLen, ed25519_key* key)
+{
+#ifdef FREESCALE_LTC_ECC
+    byte   tempBuf[ED25519_PRV_KEY_SIZE];
+#else
+    ge_p3  R;
+#endif
+    byte   nonce[SHA512_DIGEST_SIZE];
+    byte   hram[SHA512_DIGEST_SIZE];
+    byte   az[ED25519_PRV_KEY_SIZE];
+    Sha512 sha;
+    int    ret;
+
+    /* sanity check on arguments */
+    if (in == NULL || out == NULL || outLen == NULL || key == NULL)
+        return BAD_FUNC_ARG;
+
+    /* check and set up out length */
+    if (*outLen < ED25519_SIG_SIZE) {
+        *outLen = ED25519_SIG_SIZE;
+        return BUFFER_E;
+    }
+    *outLen = ED25519_SIG_SIZE;
+
+    /* step 1: create nonce to use where nonce is r in
+       r = H(h_b, ... ,h_2b-1,M) */
+    ret = wc_Sha512Hash(key->k, ED25519_KEY_SIZE, az);
+    if (ret != 0)
+        return ret;
+
+    /* apply clamp */
+    az[0]  &= 248;
+    az[31] &= 63; /* same than az[31] &= 127 because of az[31] |= 64 */
+    az[31] |= 64;
+
+    ret = wc_InitSha512(&sha);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Update(&sha, az + ED25519_KEY_SIZE, ED25519_KEY_SIZE);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Update(&sha, in, inlen);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Final(&sha, nonce);
+    if (ret != 0)
+        return ret;
+
+#ifdef FREESCALE_LTC_ECC
+    ltc_pkha_ecc_point_t ltcPoint = {0};
+    ltcPoint.X = &tempBuf[0];
+    ltcPoint.Y = &tempBuf[32];
+    LTC_PKHA_sc_reduce(nonce);
+    LTC_PKHA_Ed25519_PointMul(LTC_PKHA_Ed25519_BasePoint(), nonce, ED25519_KEY_SIZE, &ltcPoint, kLTC_Ed25519 /* result on Ed25519 */);
+    LTC_PKHA_Ed25519_Compress(&ltcPoint, out);
+#else
+    sc_reduce(nonce);
+
+    /* step 2: computing R = rB where rB is the scalar multiplication of
+       r and B */
+    ge_scalarmult_base(&R,nonce);
+    ge_p3_tobytes(out,&R);
+#endif
+
+    /* step 3: hash R + public key + message getting H(R,A,M) then
+       creating S = (r + H(R,A,M)a) mod l */
+    ret = wc_InitSha512(&sha);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Update(&sha, out, ED25519_SIG_SIZE/2);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Update(&sha, key->p, ED25519_PUB_KEY_SIZE);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Update(&sha, in, inlen);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Final(&sha, hram);
+    if (ret != 0)
+        return ret;
+
+#ifdef FREESCALE_LTC_ECC
+    LTC_PKHA_sc_reduce(hram);
+    LTC_PKHA_sc_muladd(out + (ED25519_SIG_SIZE/2), hram, az, nonce);
+#else
+    sc_reduce(hram);
+    sc_muladd(out + (ED25519_SIG_SIZE/2), hram, az, nonce);
+#endif
+
+    return ret;
+}
+
+#endif /* HAVE_ED25519_SIGN */
+
+#ifdef HAVE_ED25519_VERIFY
+
+/*
+   sig     is array of bytes containing the signature
+   siglen  is the length of sig byte array
+   msg     the array of bytes containing the message
+   msglen  length of msg array
+   res     will be 1 on successful verify and 0 on unsuccessful
+   return  0 and res of 1 on success
+*/
+int wc_ed25519_verify_msg(const byte* sig, word32 siglen, const byte* msg,
+                          word32 msglen, int* res, ed25519_key* key)
+{
+    byte   rcheck[ED25519_KEY_SIZE];
+    byte   h[SHA512_DIGEST_SIZE];
+#ifndef FREESCALE_LTC_ECC
+    ge_p3  A;
+    ge_p2  R;
+#endif
+    int    ret;
+    Sha512 sha;
+
+    /* sanity check on arguments */
+    if (sig == NULL || msg == NULL || res == NULL || key == NULL)
+        return BAD_FUNC_ARG;
+
+    /* set verification failed by default */
+    *res = 0;
+
+    /* check on basics needed to verify signature */
+    if (siglen < ED25519_SIG_SIZE || (sig[ED25519_SIG_SIZE-1] & 224))
+        return BAD_FUNC_ARG;
+
+    /* uncompress A (public key), test if valid, and negate it */
+#ifndef FREESCALE_LTC_ECC
+    if (ge_frombytes_negate_vartime(&A, key->p) != 0)
+        return BAD_FUNC_ARG;
+#endif
+
+    /* find H(R,A,M) and store it as h */
+    ret  = wc_InitSha512(&sha);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Update(&sha, sig,    ED25519_SIG_SIZE/2);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Update(&sha, key->p, ED25519_PUB_KEY_SIZE);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Update(&sha, msg,    msglen);
+    if (ret != 0)
+        return ret;
+    ret = wc_Sha512Final(&sha,  h);
+    if (ret != 0)
+        return ret;
+
+#ifdef FREESCALE_LTC_ECC
+    LTC_PKHA_sc_reduce(h);
+    LTC_PKHA_SignatureForVerify(rcheck, h, sig + (ED25519_SIG_SIZE/2), key);
+#else
+    sc_reduce(h);
+
+    /*
+       Uses a fast single-signature verification SB = R + H(R,A,M)A becomes
+       SB - H(R,A,M)A saving decompression of R
+    */
+    ret = ge_double_scalarmult_vartime(&R, h, &A, sig + (ED25519_SIG_SIZE/2));
+    if (ret != 0)
+        return ret;
+
+    ge_tobytes(rcheck, &R);
+#endif /* FREESCALE_LTC_ECC */
+
+    /* comparison of R created to R in sig */
+    ret = ConstantCompare(rcheck, sig, ED25519_SIG_SIZE/2);
+    if (ret != 0)
+        return SIG_VERIFY_E;
+
+    /* set the verification status */
+    *res = 1;
+
+    return ret;
+}
+
+#endif /* HAVE_ED25519_VERIFY */
+
+
+/* initialize information and memory for key */
+int wc_ed25519_init(ed25519_key* key)
+{
+    if (key == NULL)
+        return BAD_FUNC_ARG;
+
+    XMEMSET(key, 0, sizeof(ed25519_key));
+
+    return 0;
+}
+
+
+/* clear memory of key */
+void wc_ed25519_free(ed25519_key* key)
+{
+    if (key == NULL)
+        return;
+
+    ForceZero(key, sizeof(ed25519_key));
+}
+
+
+#ifdef HAVE_ED25519_KEY_EXPORT
+
+/*
+    outLen should contain the size of out buffer when input. outLen is than set
+    to the final output length.
+    returns 0 on success
+ */
+int wc_ed25519_export_public(ed25519_key* key, byte* out, word32* outLen)
+{
+    /* sanity check on arguments */
+    if (key == NULL || out == NULL || outLen == NULL)
+        return BAD_FUNC_ARG;
+
+    if (*outLen < ED25519_PUB_KEY_SIZE) {
+        *outLen = ED25519_PUB_KEY_SIZE;
+        return BUFFER_E;
+    }
+
+    *outLen = ED25519_PUB_KEY_SIZE;
+    XMEMCPY(out, key->p, ED25519_PUB_KEY_SIZE);
+
+    return 0;
+}
+
+#endif /* HAVE_ED25519_KEY_EXPORT */
+
+
+#ifdef HAVE_ED25519_KEY_IMPORT
+/*
+    Imports a compressed/uncompressed public key.
+    in    the byte array containing the public key
+    inLen the length of the byte array being passed in
+    key   ed25519 key struct to put the public key in
+ */
+int wc_ed25519_import_public(const byte* in, word32 inLen, ed25519_key* key)
+{
+    int    ret;
+
+    /* sanity check on arguments */
+    if (in == NULL || key == NULL)
+        return BAD_FUNC_ARG;
+
+    if (inLen < ED25519_PUB_KEY_SIZE)
+        return BAD_FUNC_ARG;
+
+    /* compressed prefix according to draft
+       http://www.ietf.org/id/draft-koch-eddsa-for-openpgp-02.txt */
+    if (in[0] == 0x40 && inLen > ED25519_PUB_KEY_SIZE) {
+        /* key is stored in compressed format so just copy in */
+        XMEMCPY(key->p, (in + 1), ED25519_PUB_KEY_SIZE);
+#ifdef FREESCALE_LTC_ECC
+        /* recover X coordinate */
+        ltc_pkha_ecc_point_t pubKey;
+        pubKey.X = key->pointX;
+        pubKey.Y = key->pointY;
+        LTC_PKHA_Ed25519_PointDecompress(key->p, ED25519_PUB_KEY_SIZE, &pubKey);
+#endif
+        return 0;
+    }
+
+    /* importing uncompressed public key */
+    if (in[0] == 0x04 && inLen > 2*ED25519_PUB_KEY_SIZE) {
+#ifdef FREESCALE_LTC_ECC
+        /* reverse bytes for little endian byte order */
+        for (int i = 0; i < ED25519_KEY_SIZE; i++)
+        {
+            key->pointX[i] = *(in + ED25519_KEY_SIZE - i);
+            key->pointY[i] = *(in + 2*ED25519_KEY_SIZE - i);
+        }
+        XMEMCPY(key->p, key->pointY, ED25519_KEY_SIZE);
+        ret = 0;
+#else
+        /* pass in (x,y) and store compressed key */
+        ret = ge_compress_key(key->p, in+1,
+                              in+1+ED25519_PUB_KEY_SIZE, ED25519_PUB_KEY_SIZE);
+#endif /* FREESCALE_LTC_ECC */
+        return ret;
+    }
+
+    /* if not specified compressed or uncompressed check key size
+       if key size is equal to compressed key size copy in key */
+    if (inLen == ED25519_PUB_KEY_SIZE) {
+        XMEMCPY(key->p, in, ED25519_PUB_KEY_SIZE);
+#ifdef FREESCALE_LTC_ECC
+        /* recover X coordinate */
+        ltc_pkha_ecc_point_t pubKey;
+        pubKey.X = key->pointX;
+        pubKey.Y = key->pointY;
+        LTC_PKHA_Ed25519_PointDecompress(key->p, ED25519_PUB_KEY_SIZE, &pubKey);
+#endif
+        return 0;
+    }
+
+    /* bad public key format */
+    return BAD_FUNC_ARG;
+}
+
+
+/*
+    For importing a private key.
+ */
+int wc_ed25519_import_private_only(const byte* priv, word32 privSz,
+                                                               ed25519_key* key)
+{
+    /* sanity check on arguments */
+    if (priv == NULL || key == NULL)
+        return BAD_FUNC_ARG;
+
+    /* key size check */
+    if (privSz < ED25519_KEY_SIZE)
+        return BAD_FUNC_ARG;
+
+    XMEMCPY(key->k, priv, ED25519_KEY_SIZE);
+
+    return 0;
+}
+
+/*
+    For importing a private key and its associated public key.
+ */
+int wc_ed25519_import_private_key(const byte* priv, word32 privSz,
+                                const byte* pub, word32 pubSz, ed25519_key* key)
+{
+    int    ret;
+
+    /* sanity check on arguments */
+    if (priv == NULL || pub == NULL || key == NULL)
+        return BAD_FUNC_ARG;
+
+    /* key size check */
+    if (privSz < ED25519_KEY_SIZE || pubSz < ED25519_PUB_KEY_SIZE)
+        return BAD_FUNC_ARG;
+
+    /* import public key */
+    ret = wc_ed25519_import_public(pub, pubSz, key);
+    if (ret != 0)
+        return ret;
+
+    /* make the private key (priv + pub) */
+    XMEMCPY(key->k, priv, ED25519_KEY_SIZE);
+    XMEMCPY(key->k + ED25519_KEY_SIZE, key->p, ED25519_PUB_KEY_SIZE);
+
+    return ret;
+}
+
+#endif /* HAVE_ED25519_KEY_IMPORT */
+
+
+#ifdef HAVE_ED25519_KEY_EXPORT
+
+/*
+ export private key only (secret part so 32 bytes)
+ outLen should contain the size of out buffer when input. outLen is than set
+ to the final output length.
+ returns 0 on success
+ */
+int wc_ed25519_export_private_only(ed25519_key* key, byte* out, word32* outLen)
+{
+    /* sanity checks on arguments */
+    if (key == NULL || out == NULL || outLen == NULL)
+        return BAD_FUNC_ARG;
+
+    if (*outLen < ED25519_KEY_SIZE) {
+        *outLen = ED25519_KEY_SIZE;
+        return BUFFER_E;
+    }
+
+    *outLen = ED25519_KEY_SIZE;
+    XMEMCPY(out, key->k, ED25519_KEY_SIZE);
+
+    return 0;
+}
+
+/*
+ export private key, including public part
+ outLen should contain the size of out buffer when input. outLen is than set
+ to the final output length.
+ returns 0 on success
+ */
+int wc_ed25519_export_private(ed25519_key* key, byte* out, word32* outLen)
+{
+    /* sanity checks on arguments */
+    if (key == NULL || out == NULL || outLen == NULL)
+        return BAD_FUNC_ARG;
+
+    if (*outLen < ED25519_PRV_KEY_SIZE) {
+        *outLen = ED25519_PRV_KEY_SIZE;
+        return BUFFER_E;
+    }
+
+    *outLen = ED25519_PRV_KEY_SIZE;
+    XMEMCPY(out, key->k, ED25519_PRV_KEY_SIZE);
+
+    return 0;
+}
+
+/* export full private key and public key
+   return 0 on success
+ */
+int wc_ed25519_export_key(ed25519_key* key,
+                          byte* priv, word32 *privSz,
+                          byte* pub, word32 *pubSz)
+{
+    int ret;
+
+    /* export 'full' private part */
+    ret = wc_ed25519_export_private(key, priv, privSz);
+    if (ret != 0)
+        return ret;
+
+    /* export public part */
+    ret = wc_ed25519_export_public(key, pub, pubSz);
+
+    return ret;
+}
+
+#endif /* HAVE_ED25519_KEY_EXPORT */
+
+/* check the private and public keys match */
+int wc_ed25519_check_key(ed25519_key* key)
+{
+    /* TODO: Perform check of private and public key */
+    (void)key;
+
+    return 0;
+}
+
+/* returns the private key size (secret only) in bytes */
+int wc_ed25519_size(ed25519_key* key)
+{
+    if (key == NULL)
+        return BAD_FUNC_ARG;
+
+    return ED25519_KEY_SIZE;
+}
+
+/* returns the private key size (secret + public) in bytes */
+int wc_ed25519_priv_size(ed25519_key* key)
+{
+    if (key == NULL)
+        return BAD_FUNC_ARG;
+
+    return ED25519_PRV_KEY_SIZE;
+}
+
+/* returns the compressed key size in bytes (public key) */
+int wc_ed25519_pub_size(ed25519_key* key)
+{
+    if (key == NULL)
+        return BAD_FUNC_ARG;
+
+    return ED25519_PUB_KEY_SIZE;
+}
+
+/* returns the size of signature in bytes */
+int wc_ed25519_sig_size(ed25519_key* key)
+{
+    if (key == NULL)
+        return BAD_FUNC_ARG;
+
+    return ED25519_SIG_SIZE;
+}
+
+#endif /* HAVE_ED25519 */
+
+