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Improvement to ECC wc_ecc_rs_raw_to_sig to reduce memory use (avoid the mp_int). Additional test cases. Fixes for previous function changes.

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This commit is contained in:
David Garske
2020-10-23 11:00:46 -07:00
parent 0065756efc
commit 589057245f
4 changed files with 100 additions and 76 deletions
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78
wolfcrypt/src/asn.c
View File

@ -15427,6 +15427,66 @@ int StoreECC_DSA_Sig(byte* out, word32* outLen, mp_int* r, mp_int* s)
return 0;
}
/* determine if leading bit is set and trim leading zeros */
static int is_leading_bit_set(const byte** input, word32 *sz)
{
int i;
word32 leadingZeroCount = 0;
const byte* tmp = *input;
byte c = 0;
for (i=0; i<(int)*sz; i++) {
c = tmp[i];
if (c != 0)
break;
leadingZeroCount++;
}
*input += leadingZeroCount;
*sz -= leadingZeroCount;
return (c & 0x80) != 0;
}
/* Der Encode r & s ints into out, outLen is (in/out) size */
int StoreECC_DSA_Sig_Bin(byte* out, word32* outLen, const byte* r, word32 rLen,
const byte* s, word32 sLen)
{
int ret;
word32 idx;
word32 headerSz = 4; /* 2*ASN_TAG + 2*LEN(ENUM) */
int rAddLeadZero, sAddLeadZero;
/* If the leading bit on the INTEGER is a 1, add a leading zero */
/* Add leading zero if MSB is set */
/* Trim leading zeros */
rAddLeadZero = is_leading_bit_set(&r, &rLen);
sAddLeadZero = is_leading_bit_set(&s, &sLen);
if (*outLen < (rLen + rAddLeadZero + sLen + sAddLeadZero +
headerSz + 2)) /* SEQ_TAG + LEN(ENUM) */
return BUFFER_E;
idx = SetSequence(rLen+rAddLeadZero + sLen+sAddLeadZero + headerSz, out);
/* store r */
ret = SetASNInt(rLen, rAddLeadZero ? 0x80 : 0x00, &out[idx]);
if (ret < 0)
return ret;
idx += ret;
XMEMCPY(&out[idx], r, rLen);
idx += rLen;
/* store s */
ret = SetASNInt(sLen, sAddLeadZero ? 0x80 : 0x00, &out[idx]);
if (ret < 0)
return ret;
idx += ret;
XMEMCPY(&out[idx], s, sLen);
idx += sLen;
*outLen = idx;
return 0;
}
/* Der Decode ECC-DSA Signature with R/S as unsigned bin */
int DecodeECC_DSA_Sig_Bin(const byte* sig, word32 sigLen, byte* r, word32* rLen,
@ -15546,18 +15606,18 @@ int wc_EccPrivateKeyDecode(const byte* input, word32* inOutIdx, ecc_key* key,
if (GetLength(input, inOutIdx, &length, inSz) < 0)
return ASN_PARSE_E;
privSz = length;
if (length > ECC_MAXSIZE)
if (privSz > ECC_MAXSIZE)
return BUFFER_E;
#ifdef WOLFSSL_SMALL_STACK
priv = (byte*)XMALLOC(length+1, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
priv = (byte*)XMALLOC(privSz, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
if (priv == NULL)
return MEMORY_E;
#endif
/* priv key */
privSz = length;
XMEMCPY(priv, &input[*inOutIdx], privSz);
*inOutIdx += length;
@ -15601,13 +15661,13 @@ int wc_EccPrivateKeyDecode(const byte* input, word32* inOutIdx, ecc_key* key,
if (ret == 0) {
/* pub key */
pubSz = length;
if (pubSz <= 2*ECC_MAXSIZE) {
if (pubSz > 2*(ECC_MAXSIZE+1))
ret = BUFFER_E;
else {
#ifdef WOLFSSL_SMALL_STACK
pub = (byte*)XMALLOC(pubSz+1, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
if (pub == NULL) {
XFREE(priv, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
pub = (byte*)XMALLOC(pubSz, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
if (pub == NULL)
ret = MEMORY_E;
}
else
#endif
{
@ -15616,8 +15676,6 @@ int wc_EccPrivateKeyDecode(const byte* input, word32* inOutIdx, ecc_key* key,
pubData = pub;
}
}
else
ret = BUFFER_E;
}
}
}

50
wolfcrypt/src/ecc.c
View File

@ -7972,59 +7972,11 @@ int wc_ecc_rs_to_sig(const char* r, const char* s, byte* out, word32* outlen)
int wc_ecc_rs_raw_to_sig(const byte* r, word32 rSz, const byte* s, word32 sSz,
byte* out, word32* outlen)
{
int err;
#ifdef WOLFSSL_SMALL_STACK
mp_int* rtmp = NULL;
mp_int* stmp = NULL;
#else
mp_int rtmp[1];
mp_int stmp[1];
#endif
if (r == NULL || s == NULL || out == NULL || outlen == NULL)
return ECC_BAD_ARG_E;
#ifdef WOLFSSL_SMALL_STACK
rtmp = (mp_int*)XMALLOC(sizeof(mp_int), NULL, DYNAMIC_TYPE_ECC);
if (rtmp == NULL)
return MEMORY_E;
stmp = (mp_int*)XMALLOC(sizeof(mp_int), NULL, DYNAMIC_TYPE_ECC);
if (stmp == NULL) {
XFREE(rtmp, NULL, DYNAMIC_TYPE_ECC);
return MEMORY_E;
}
#endif
err = mp_init_multi(rtmp, stmp, NULL, NULL, NULL, NULL);
if (err != MP_OKAY) {
#ifdef WOLFSSL_SMALL_STACK
XFREE(stmp, NULL, DYNAMIC_TYPE_ECC);
XFREE(rtmp, NULL, DYNAMIC_TYPE_ECC);
#endif
return err;
}
err = mp_read_unsigned_bin(rtmp, r, rSz);
if (err == MP_OKAY)
err = mp_read_unsigned_bin(stmp, s, sSz);
/* convert mp_ints to ECDSA sig, initializes rtmp and stmp internally */
if (err == MP_OKAY)
err = StoreECC_DSA_Sig(out, outlen, rtmp, stmp);
if (err == MP_OKAY) {
if (mp_iszero(rtmp) == MP_YES || mp_iszero(stmp) == MP_YES)
err = MP_ZERO_E;
}
mp_clear(rtmp);
mp_clear(stmp);
#ifdef WOLFSSL_SMALL_STACK
XFREE(stmp, NULL, DYNAMIC_TYPE_ECC);
XFREE(rtmp, NULL, DYNAMIC_TYPE_ECC);
#endif
return err;
return StoreECC_DSA_Sig_Bin(out, outlen, r, rSz, s, sSz);
}
/**

46
wolfcrypt/test/test.c
View File

@ -18297,12 +18297,14 @@ static int ecc_test_vector_item(const eccVector* vector)
#ifdef WOLFSSL_SMALL_STACK
ecc_key *userA = (ecc_key *)XMALLOC(sizeof *userA, HEAP_HINT, DYNAMIC_TYPE_TMP_BUFFER);
#else
ecc_key userA_buf, *userA = &userA_buf;
ecc_key userA[1];
#endif
DECLARE_VAR(sig, byte, ECC_SIG_SIZE, HEAP_HINT);
#if !defined(NO_ASN) && !defined(HAVE_SELFTEST)
word32 sigRawSz;
word32 sigRawSz, rSz = MAX_ECC_BYTES, sSz = MAX_ECC_BYTES;
DECLARE_VAR(sigRaw, byte, ECC_SIG_SIZE, HEAP_HINT);
DECLARE_VAR(r, byte, MAX_ECC_BYTES, HEAP_HINT);
DECLARE_VAR(s, byte, MAX_ECC_BYTES, HEAP_HINT);
#endif
#ifdef DECLARE_VAR_IS_HEAP_ALLOC
@ -18341,11 +18343,19 @@ static int ecc_test_vector_item(const eccVector* vector)
sigRaw, &sigRawSz);
if (ret != 0)
goto done;
if (sigSz != sigRawSz || XMEMCMP(sig, sigRaw, sigSz) != 0) {
ret = -9608;
goto done;
}
ret = wc_ecc_sig_to_rs(sig, sigSz, r, &rSz, s, &sSz);
if (ret != 0)
goto done;
if (rSz != vector->rSz || XMEMCMP(r, vector->r, rSz) != 0 ||
sSz != vector->sSz || XMEMCMP(s, vector->s, sSz) != 0) {
ret = -9613;
goto done;
}
#endif
do {
@ -18376,6 +18386,8 @@ done:
#if !defined(NO_ASN) && !defined(HAVE_SELFTEST)
FREE_VAR(sigRaw, HEAP_HINT);
FREE_VAR(r, HEAP_HINT);
FREE_VAR(s, HEAP_HINT);
#endif
FREE_VAR(sig, HEAP_HINT);
@ -18598,20 +18610,20 @@ static int ecc_test_vector(int keySize)
vec.S = "019cd2c5c3f9870ecdeb9b323abdf3a98cd5e231d85c6ddc5b71ab190739f7f226e6b134ba1d5889ddeb2751dabd97911dff90c34684cdbe7bb669b6c3d22f2480c";
vec.curveName = "SECP521R1";
#ifndef NO_ASN
vec.r = (byte*)"\x00\xbd\x11\x7b\x48\x07\x71\x08\x98\xf9\xdd\x77"
"\x78\x05\x64\x85\x77\x76\x68\xf0\xe7\x8e\x6d\xdf"
"\x5b\x00\x03\x56\x12\x1e\xb7\xa2\x20\xe9\x49\x3c"
"\x7f\x9a\x57\xc0\x77\x94\x7f\x89\xac\x45\xd5\xac"
"\xb6\x66\x1b\xbc\xd1\x7a\xbb\x3f\xae\xa1\x49\xba"
"\x0a\xa3\xbb\x15\x21\xbe";
vec.rSz = 66;
vec.s = (byte*)"\x00\x19\xcd\x2c\x5c\x3f\x98\x70\xec\xde\xb9\xb3"
"\x23\xab\xdf\x3a\x98\xcd\x5e\x23\x1d\x85\xc6\xdd"
"\xc5\xb7\x1a\xb1\x90\x73\x9f\x7f\x22\x6e\x6b\x13"
"\x4b\xa1\xd5\x88\x9d\xde\xb2\x75\x1d\xab\xd9\x79"
"\x11\xdf\xf9\x0c\x34\x68\x4c\xdb\xe7\xbb\x66\x9b"
"\x6c\x3d\x22\xf2\x48\x0c";
vec.sSz = 66;
vec.r = (byte*)"\xbd\x11\x7b\x48\x07\x71\x08\x98\xf9\xdd\x77\x78"
"\x05\x64\x85\x77\x76\x68\xf0\xe7\x8e\x6d\xdf\x5b"
"\x00\x03\x56\x12\x1e\xb7\xa2\x20\xe9\x49\x3c\x7f"
"\x9a\x57\xc0\x77\x94\x7f\x89\xac\x45\xd5\xac\xb6"
"\x66\x1b\xbc\xd1\x7a\xbb\x3f\xae\xa1\x49\xba\x0a"
"\xa3\xbb\x15\x21\xbe";
vec.rSz = 65;
vec.s = (byte*)"\x19\xcd\x2c\x5c\x3f\x98\x70\xec\xde\xb9\xb3\x23"
"\xab\xdf\x3a\x98\xcd\x5e\x23\x1d\x85\xc6\xdd\xc5"
"\xb7\x1a\xb1\x90\x73\x9f\x7f\x22\x6e\x6b\x13\x4b"
"\xa1\xd5\x88\x9d\xde\xb2\x75\x1d\xab\xd9\x79\x11"
"\xdf\xf9\x0c\x34\x68\x4c\xdb\xe7\xbb\x66\x9b\x6c"
"\x3d\x22\xf2\x48\x0c";
vec.sSz = 65;
#endif
break;
#endif /* HAVE_ECC521 */

2
wolfssl/wolfcrypt/asn.h
View File

@ -1162,6 +1162,8 @@ WOLFSSL_LOCAL int FlattenAltNames( byte*, word32, const DNS_entry*);
/* ASN sig helpers */
WOLFSSL_LOCAL int StoreECC_DSA_Sig(byte* out, word32* outLen, mp_int* r,
mp_int* s);
WOLFSSL_LOCAL int StoreECC_DSA_Sig_Bin(byte* out, word32* outLen,
const byte* r, word32 rLen, const byte* s, word32 sLen);
WOLFSSL_LOCAL int DecodeECC_DSA_Sig(const byte* sig, word32 sigLen,
mp_int* r, mp_int* s);
WOLFSSL_LOCAL int DecodeECC_DSA_Sig_Bin(const byte* sig, word32 sigLen,