Move secp256k1_ec_privkey_import/export to contrib.

These functions are intended for compatibility with legacy software,
 and are not normally needed in new secp256k1 applications.

They also do not obeying any particular standard (and likely cannot
 without without undermining their compatibility), and so are a
 better fit for contrib.
This commit is contained in:
Gregory Maxwell
2015-10-21 04:02:30 +00:00
parent 1b3efc1147
commit 4a243da47c
6 changed files with 215 additions and 186 deletions

View File

@@ -51,109 +51,6 @@ static int secp256k1_eckey_pubkey_serialize(secp256k1_ge *elem, unsigned char *p
return 1;
}
static int secp256k1_eckey_privkey_parse(secp256k1_scalar *key, const unsigned char *privkey, size_t privkeylen) {
unsigned char c[32] = {0};
const unsigned char *end = privkey + privkeylen;
int lenb = 0;
int len = 0;
int overflow = 0;
/* sequence header */
if (end < privkey+1 || *privkey != 0x30) {
return 0;
}
privkey++;
/* sequence length constructor */
if (end < privkey+1 || !(*privkey & 0x80)) {
return 0;
}
lenb = *privkey & ~0x80; privkey++;
if (lenb < 1 || lenb > 2) {
return 0;
}
if (end < privkey+lenb) {
return 0;
}
/* sequence length */
len = privkey[lenb-1] | (lenb > 1 ? privkey[lenb-2] << 8 : 0);
privkey += lenb;
if (end < privkey+len) {
return 0;
}
/* sequence element 0: version number (=1) */
if (end < privkey+3 || privkey[0] != 0x02 || privkey[1] != 0x01 || privkey[2] != 0x01) {
return 0;
}
privkey += 3;
/* sequence element 1: octet string, up to 32 bytes */
if (end < privkey+2 || privkey[0] != 0x04 || privkey[1] > 0x20 || end < privkey+2+privkey[1]) {
return 0;
}
memcpy(c + 32 - privkey[1], privkey + 2, privkey[1]);
secp256k1_scalar_set_b32(key, c, &overflow);
memset(c, 0, 32);
return !overflow;
}
static int secp256k1_eckey_privkey_serialize(const secp256k1_ecmult_gen_context *ctx, unsigned char *privkey, size_t *privkeylen, const secp256k1_scalar *key, unsigned int flags) {
secp256k1_gej rp;
secp256k1_ge r;
size_t pubkeylen = 0;
secp256k1_ecmult_gen(ctx, &rp, key);
secp256k1_ge_set_gej(&r, &rp);
if (flags & SECP256K1_EC_COMPRESSED) {
static const unsigned char begin[] = {
0x30,0x81,0xD3,0x02,0x01,0x01,0x04,0x20
};
static const unsigned char middle[] = {
0xA0,0x81,0x85,0x30,0x81,0x82,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,
0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,
0x21,0x02,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,
0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
0x17,0x98,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,
0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x24,0x03,0x22,0x00
};
unsigned char *ptr = privkey;
memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
secp256k1_scalar_get_b32(ptr, key); ptr += 32;
memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
if (!secp256k1_eckey_pubkey_serialize(&r, ptr, &pubkeylen, 1)) {
return 0;
}
ptr += pubkeylen;
*privkeylen = ptr - privkey;
} else {
static const unsigned char begin[] = {
0x30,0x82,0x01,0x13,0x02,0x01,0x01,0x04,0x20
};
static const unsigned char middle[] = {
0xA0,0x81,0xA5,0x30,0x81,0xA2,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,
0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,
0x41,0x04,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,
0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
0x17,0x98,0x48,0x3A,0xDA,0x77,0x26,0xA3,0xC4,0x65,0x5D,0xA4,0xFB,0xFC,0x0E,0x11,
0x08,0xA8,0xFD,0x17,0xB4,0x48,0xA6,0x85,0x54,0x19,0x9C,0x47,0xD0,0x8F,0xFB,0x10,
0xD4,0xB8,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,
0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x44,0x03,0x42,0x00
};
unsigned char *ptr = privkey;
memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
secp256k1_scalar_get_b32(ptr, key); ptr += 32;
memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
if (!secp256k1_eckey_pubkey_serialize(&r, ptr, &pubkeylen, 0)) {
return 0;
}
ptr += pubkeylen;
*privkeylen = ptr - privkey;
}
return 1;
}
static int secp256k1_eckey_privkey_tweak_add(secp256k1_scalar *key, const secp256k1_scalar *tweak) {
secp256k1_scalar_add(key, key, tweak);
if (secp256k1_scalar_is_zero(key)) {

View File

@@ -501,36 +501,6 @@ int secp256k1_ec_pubkey_tweak_mul(const secp256k1_context* ctx, secp256k1_pubkey
return ret;
}
int secp256k1_ec_privkey_export(const secp256k1_context* ctx, unsigned char *privkey, size_t *privkeylen, const unsigned char *seckey, unsigned int flags) {
secp256k1_scalar key;
int ret = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(seckey != NULL);
ARG_CHECK(privkey != NULL);
ARG_CHECK(privkeylen != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
secp256k1_scalar_set_b32(&key, seckey, NULL);
ret = secp256k1_eckey_privkey_serialize(&ctx->ecmult_gen_ctx, privkey, privkeylen, &key, flags);
secp256k1_scalar_clear(&key);
return ret;
}
int secp256k1_ec_privkey_import(const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *privkey, size_t privkeylen) {
secp256k1_scalar key;
int ret = 0;
ARG_CHECK(seckey != NULL);
ARG_CHECK(privkey != NULL);
(void)ctx;
ret = secp256k1_eckey_privkey_parse(&key, privkey, privkeylen);
if (ret) {
secp256k1_scalar_get_b32(seckey, &key);
}
secp256k1_scalar_clear(&key);
return ret;
}
int secp256k1_context_randomize(secp256k1_context* ctx, const unsigned char *seed32) {
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));

View File

@@ -25,6 +25,7 @@
#endif
#include "contrib/lax_der_parsing.h"
#include "contrib/lax_der_privatekey_parsing.h"
#if !defined(VG_CHECK)
# if defined(VALGRIND)
@@ -2351,8 +2352,8 @@ void test_ecdsa_end_to_end(void) {
CHECK(secp256k1_ec_pubkey_parse(ctx, &pubkey, pubkeyc, pubkeyclen) == 1);
/* Verify private key import and export. */
CHECK(secp256k1_ec_privkey_export(ctx, seckey, &seckeylen, privkey, secp256k1_rand_bits(1) == 1) ? SECP256K1_EC_COMPRESSED : 0);
CHECK(secp256k1_ec_privkey_import(ctx, privkey2, seckey, seckeylen) == 1);
CHECK(secp256k1_ec_privkey_export_der(ctx, seckey, &seckeylen, privkey, secp256k1_rand_bits(1) == 1) ? SECP256K1_EC_COMPRESSED : 0);
CHECK(secp256k1_ec_privkey_import_der(ctx, privkey2, seckey, seckeylen) == 1);
CHECK(memcmp(privkey, privkey2, 32) == 0);
/* Optionally tweak the keys using addition. */
@@ -2998,9 +2999,9 @@ void test_ecdsa_edge_cases(void) {
0xbf, 0xd2, 0x5e, 0x8c, 0xd0, 0x36, 0x41, 0x41,
};
size_t outlen = 300;
CHECK(!secp256k1_ec_privkey_export(ctx, privkey, &outlen, seckey, 0));
CHECK(!secp256k1_ec_privkey_export_der(ctx, privkey, &outlen, seckey, 0));
outlen = 300;
CHECK(!secp256k1_ec_privkey_export(ctx, privkey, &outlen, seckey, SECP256K1_EC_COMPRESSED));
CHECK(!secp256k1_ec_privkey_export_der(ctx, privkey, &outlen, seckey, SECP256K1_EC_COMPRESSED));
}
}