From 3fd32df8edf9f22b630c7beac64aa4be5077e1db Mon Sep 17 00:00:00 2001 From: netanelkl Date: Thu, 9 Apr 2015 15:05:28 -0400 Subject: [PATCH] More of the same. --- bignum.c | 12 +++++ ecdsa.c | 134 ++++++++++++++++++++++++++++++++++++++----------------- hmac.c | 9 ++++ pbkdf2.c | 7 +++ 4 files changed, 122 insertions(+), 40 deletions(-) diff --git a/bignum.c b/bignum.c index 26cb93814e..134f8ee08c 100644 --- a/bignum.c +++ b/bignum.c @@ -26,6 +26,7 @@ #include #include "bignum.h" #include "secp256k1.h" +#include "macro_utils.h" inline uint32_t read_be(const uint8_t *data) { @@ -252,6 +253,8 @@ void bn_multiply(const bignum256 *k, bignum256 *x, const bignum256 *prime) for (i = 0; i < 9; i++) { x->val[i] = res[i]; } + + MEMSET_BZERO(res,sizeof(res)); } // input x can be any normalized number that fits (0 <= x < 2^270). @@ -309,6 +312,10 @@ void bn_sqrt(bignum256 *x, const bignum256 *prime) } bn_mod(&res, prime); memcpy(x, &res, sizeof(bignum256)); + + MEMSET_BZERO(&res, sizeof(res)); + MEMSET_BZERO(&p, sizeof(p)); + } #if ! USE_INVERSE_FAST @@ -614,6 +621,11 @@ void bn_inverse(bignum256 *x, const bignum256 *prime) temp32 = us.a[8-i] >> (30 - 2 * i); } x->val[i] = temp32; + + // Let's wipe all temp buffers. + MEMSET_BZERO(pp, sizeof(pp)); + MEMSET_BZERO(&us, sizeof(us)); + MEMSET_BZERO(&vr, sizeof(vr)); } #endif diff --git a/ecdsa.c b/ecdsa.c index 05efc9771f..8fe28f7f52 100644 --- a/ecdsa.c +++ b/ecdsa.c @@ -33,6 +33,7 @@ #include "hmac.h" #include "ecdsa.h" #include "base58.h" +#include "macro_utils.h" // Set cp2 = cp1 void point_copy(const curve_point *cp1, curve_point *cp2) @@ -654,7 +655,11 @@ int ecdsa_sign(const uint8_t *priv_key, const uint8_t *msg, uint32_t msg_len, ui { uint8_t hash[32]; sha256_Raw(msg, msg_len, hash); - return ecdsa_sign_digest(priv_key, hash, sig, pby); + int res = ecdsa_sign_digest(priv_key, hash, sig, pby); + + MEMSET_BZERO(hash, sizeof(hash)); + return res; + } // msg is a data to be signed @@ -664,7 +669,11 @@ int ecdsa_sign_double(const uint8_t *priv_key, const uint8_t *msg, uint32_t msg_ uint8_t hash[32]; sha256_Raw(msg, msg_len, hash); sha256_Raw(hash, 32, hash); - return ecdsa_sign_digest(priv_key, hash, sig, pby); + int res = ecdsa_sign_digest(priv_key, hash, sig, pby); + + MEMSET_BZERO(hash, sizeof(hash)); + + return res; } // uses secp256k1 curve @@ -677,56 +686,71 @@ int ecdsa_sign_digest(const uint8_t *priv_key, const uint8_t *digest, uint8_t *s curve_point R; bignum256 k, z; bignum256 *da = &R.y; - + int result = 0; bn_read_be(digest, &z); #if USE_RFC6979 // generate K deterministically if (generate_k_rfc6979(&k, priv_key, digest) != 0) { - return 1; + result = 1; } #else // generate random number k if (generate_k_random(&k) != 0) { - return 1; + result = 1; } #endif - // compute k*G - scalar_multiply(&k, &R); - if (pby) { - *pby = R.y.val[0] & 1; - } - // r = (rx mod n) - bn_mod(&R.x, &order256k1); - // if r is zero, we fail - if (bn_is_zero(&R.x)) return 2; - bn_inverse(&k, &order256k1); - bn_read_be(priv_key, da); - bn_multiply(&R.x, da, &order256k1); - for (i = 0; i < 8; i++) { - da->val[i] += z.val[i]; - da->val[i + 1] += (da->val[i] >> 30); - da->val[i] &= 0x3FFFFFFF; - } - da->val[8] += z.val[8]; - bn_multiply(da, &k, &order256k1); - bn_mod(&k, &order256k1); - // if k is zero, we fail - if (bn_is_zero(&k)) return 3; - - // if S > order/2 => S = -S - if (bn_is_less(&order256k1_half, &k)) { - bn_subtract(&order256k1, &k, &k); + if(result == 0) { + // compute k*G + scalar_multiply(&k, &R); if (pby) { - *pby = !*pby; + *pby = R.y.val[0] & 1; + } + // r = (rx mod n) + bn_mod(&R.x, &order256k1); + // if r is zero, we fail + if (bn_is_zero(&R.x)) + { + result = 2; } } - // we are done, R.x and k is the result signature - bn_write_be(&R.x, sig); - bn_write_be(&k, sig + 32); + if(result == 0) { + bn_inverse(&k, &order256k1); + bn_read_be(priv_key, da); + bn_multiply(&R.x, da, &order256k1); + for (i = 0; i < 8; i++) { + da->val[i] += z.val[i]; + da->val[i + 1] += (da->val[i] >> 30); + da->val[i] &= 0x3FFFFFFF; + } + da->val[8] += z.val[8]; + bn_multiply(da, &k, &order256k1); + bn_mod(&k, &order256k1); + // if k is zero, we fail + if (bn_is_zero(&k)) { + result = 3; + } + } + if(result == 0) + { + // if S > order/2 => S = -S + if (bn_is_less(&order256k1_half, &k)) { + bn_subtract(&order256k1, &k, &k); + if (pby) { + *pby = !*pby; + } + } + // we are done, R.x and k is the result signature + bn_write_be(&R.x, sig); + bn_write_be(&k, sig + 32); + } + + MEMSET_BZERO(&k,sizeof(k)); + MEMSET_BZERO(&z,sizeof(z)); + MEMSET_BZERO(&R,sizeof(R)); return 0; } @@ -740,6 +764,8 @@ void ecdsa_get_public_key33(const uint8_t *priv_key, uint8_t *pub_key) scalar_multiply(&k, &R); pub_key[0] = 0x02 | (R.y.val[0] & 0x01); bn_write_be(&R.x, pub_key + 1); + MEMSET_BZERO(&R,sizeof(R)); + MEMSET_BZERO(&k,sizeof(k)); } void ecdsa_get_public_key65(const uint8_t *priv_key, uint8_t *pub_key) @@ -753,6 +779,8 @@ void ecdsa_get_public_key65(const uint8_t *priv_key, uint8_t *pub_key) pub_key[0] = 0x04; bn_write_be(&R.x, pub_key + 1); bn_write_be(&R.y, pub_key + 33); + MEMSET_BZERO(&R,sizeof(R)); + MEMSET_BZERO(&k,sizeof(k)); } void ecdsa_get_pubkeyhash(const uint8_t *pub_key, uint8_t *pubkeyhash) @@ -766,6 +794,7 @@ void ecdsa_get_pubkeyhash(const uint8_t *pub_key, uint8_t *pubkeyhash) sha256_Raw(pub_key, 33, h); // expecting compressed format } ripemd160(h, 32, pubkeyhash); + MEMSET_BZERO(h,sizeof(h)); } void ecdsa_get_address_raw(const uint8_t *pub_key, uint8_t version, uint8_t *addr_raw) @@ -779,6 +808,9 @@ void ecdsa_get_address(const uint8_t *pub_key, uint8_t version, char *addr, int uint8_t raw[21]; ecdsa_get_address_raw(pub_key, version, raw); base58_encode_check(raw, 21, addr, addrsize); + + // Not as important to clear this one, but we might as well. + MEMSET_BZERO(raw,sizeof(raw)); } void ecdsa_get_wif(const uint8_t *priv_key, uint8_t version, char *wif, int wifsize) @@ -788,6 +820,9 @@ void ecdsa_get_wif(const uint8_t *priv_key, uint8_t version, char *wif, int wifs memcpy(data + 1, priv_key, 32); data[33] = 0x01; base58_encode_check(data, 34, wif, wifsize); + + // This private keys running around our stack can cause trouble! + MEMSET_BZERO(data,sizeof(data)); } int ecdsa_address_decode(const char *addr, uint8_t *out) @@ -871,7 +906,10 @@ int ecdsa_verify(const uint8_t *pub_key, const uint8_t *sig, const uint8_t *msg, { uint8_t hash[32]; sha256_Raw(msg, msg_len, hash); - return ecdsa_verify_digest(pub_key, sig, hash); + int res = ecdsa_verify_digest(pub_key, sig, hash); + + MEMSET_BZERO(hash,sizeof(hash)); + return res; } int ecdsa_verify_double(const uint8_t *pub_key, const uint8_t *sig, const uint8_t *msg, uint32_t msg_len) @@ -879,7 +917,11 @@ int ecdsa_verify_double(const uint8_t *pub_key, const uint8_t *sig, const uint8_ uint8_t hash[32]; sha256_Raw(msg, msg_len, hash); sha256_Raw(hash, 32, hash); - return ecdsa_verify_digest(pub_key, sig, hash); + + int res = ecdsa_verify_digest(pub_key, sig, hash); + + MEMSET_BZERO(hash,sizeof(hash)); + return res; } // returns 0 if verification succeeded @@ -906,24 +948,36 @@ int ecdsa_verify_digest(const uint8_t *pub_key, const uint8_t *sig, const uint8_ bn_mod(&z, &order256k1); bn_multiply(&r, &s, &order256k1); // r*s^-1 bn_mod(&s, &order256k1); + + int result = 0; if (bn_is_zero(&z)) { // our message hashes to zero // I don't expect this to happen any time soon - return 3; + result = 3; } else { scalar_multiply(&z, &res); } + if(result == 0) { + // both pub and res can be infinity, can have y = 0 OR can be equal -> false negative point_multiply(&s, &pub, &pub); point_add(&pub, &res); bn_mod(&(res.x), &order256k1); // signature does not match - if (!bn_is_equal(&res.x, &r)) return 5; + if (!bn_is_equal(&res.x, &r)) { + result = 5; + } + } + MEMSET_BZERO(&pub,sizeof(pub)); + MEMSET_BZERO(&res,sizeof(res)); + MEMSET_BZERO(&r,sizeof(r)); + MEMSET_BZERO(&s,sizeof(s)); + MEMSET_BZERO(&z,sizeof(z)); // all OK - return 0; + return result; } int ecdsa_sig_to_der(const uint8_t *sig, uint8_t *der) diff --git a/hmac.c b/hmac.c index a8d95ff8db..a43d2a7a61 100644 --- a/hmac.c +++ b/hmac.c @@ -25,6 +25,7 @@ #include "hmac.h" #include "sha2.h" +#include "macro_utils.h" void hmac_sha256(const uint8_t *key, const uint32_t keylen, const uint8_t *msg, const uint32_t msglen, uint8_t *hmac) { @@ -53,6 +54,10 @@ void hmac_sha256(const uint8_t *key, const uint32_t keylen, const uint8_t *msg, sha256_Update(&ctx, o_key_pad, SHA256_BLOCK_LENGTH); sha256_Update(&ctx, buf, SHA256_DIGEST_LENGTH); sha256_Final(hmac, &ctx); + MEMSET_BZERO(buf,sizeof(buf)); + MEMSET_BZERO(o_key_pad,sizeof(o_key_pad)); + MEMSET_BZERO(i_key_pad,sizeof(i_key_pad)); + } void hmac_sha512(const uint8_t *key, const uint32_t keylen, const uint8_t *msg, const uint32_t msglen, uint8_t *hmac) @@ -82,4 +87,8 @@ void hmac_sha512(const uint8_t *key, const uint32_t keylen, const uint8_t *msg, sha512_Update(&ctx, o_key_pad, SHA512_BLOCK_LENGTH); sha512_Update(&ctx, buf, SHA512_DIGEST_LENGTH); sha512_Final(hmac, &ctx); + + MEMSET_BZERO(buf,sizeof(buf)); + MEMSET_BZERO(o_key_pad,sizeof(o_key_pad)); + MEMSET_BZERO(i_key_pad,sizeof(i_key_pad)); } diff --git a/pbkdf2.c b/pbkdf2.c index 2271f997c4..256ef86e16 100644 --- a/pbkdf2.c +++ b/pbkdf2.c @@ -24,6 +24,7 @@ #include #include "pbkdf2.h" #include "hmac.h" +#include "macro_utils.h" void pbkdf2_hmac_sha256(const uint8_t *pass, int passlen, uint8_t *salt, int saltlen, uint32_t iterations, uint8_t *key, int keylen, void (*progress_callback)(uint32_t current, uint32_t total)) { @@ -56,6 +57,9 @@ void pbkdf2_hmac_sha256(const uint8_t *pass, int passlen, uint8_t *salt, int sal memcpy(key + HMACLEN * (i - 1), f, HMACLEN); } } + + MEMSET_BZERO(f,sizeof(f)); + MEMSET_BZERO(g, sizeof(g)); } void pbkdf2_hmac_sha512(const uint8_t *pass, int passlen, uint8_t *salt, int saltlen, uint32_t iterations, uint8_t *key, int keylen, void (*progress_callback)(uint32_t current, uint32_t total)) @@ -89,4 +93,7 @@ void pbkdf2_hmac_sha512(const uint8_t *pass, int passlen, uint8_t *salt, int sal memcpy(key + HMACLEN * (i - 1), f, HMACLEN); } } + + MEMSET_BZERO(f,sizeof(f)); + MEMSET_BZERO(g, sizeof(g)); }