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Make lax_der_privatekey_parsing.h not depend on internal code

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This commit is contained in:
Pieter Wuille
2015-10-26 02:51:42 +01:00
parent 73f64ff8f3
commit 7914a6ebae
2 changed files with 23 additions and 53 deletions
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68
contrib/lax_der_privatekey_parsing.h
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@@ -73,12 +73,11 @@ static SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_import_der(
size_t privkeylen
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
static int secp256k1_eckey_privkey_parse(secp256k1_scalar *key, const unsigned char *privkey, size_t privkeylen) {
unsigned char c[32] = {0};
static int secp256k1_ec_privkey_import_der(const secp256k1_context* ctx, unsigned char *out32, const unsigned char *privkey, size_t privkeylen) {
const unsigned char *end = privkey + privkeylen;
int lenb = 0;
int len = 0;
int overflow = 0;
memset(out32, 0, 32);
/* sequence header */
if (end < privkey+1 || *privkey != 0x30) {
return 0;
@@ -110,18 +109,21 @@ static int secp256k1_eckey_privkey_parse(secp256k1_scalar *key, const unsigned c
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;
memcpy(out32 + 32 - privkey[1], privkey + 2, privkey[1]);
if (!secp256k1_ec_seckey_verify(ctx, out32)) {
memset(out32, 0, 32);
return 0;
}
return 1;
}
static int secp256k1_eckey_privkey_serialize(const secp256k1_ecmult_gen_context *ctx, unsigned char *privkey, size_t *privkeylen, const secp256k1_scalar *key, int compressed) {
secp256k1_gej rp;
secp256k1_ge r;
static int secp256k1_ec_privkey_export_der(const secp256k1_context *ctx, unsigned char *privkey, size_t *privkeylen, const unsigned char *key32, int compressed) {
secp256k1_pubkey pubkey;
size_t pubkeylen = 0;
secp256k1_ecmult_gen(ctx, &rp, key);
secp256k1_ge_set_gej(&r, &rp);
if (!secp256k1_ec_pubkey_create(ctx, &pubkey, key32)) {
*privkeylen = 0;
return 0;
}
if (compressed) {
static const unsigned char begin[] = {
0x30,0x81,0xD3,0x02,0x01,0x01,0x04,0x20
@@ -139,11 +141,9 @@ static int secp256k1_eckey_privkey_serialize(const secp256k1_ecmult_gen_context
};
unsigned char *ptr = privkey;
memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
secp256k1_scalar_get_b32(ptr, key); ptr += 32;
memcpy(ptr, key32, 32); ptr += 32;
memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
if (!secp256k1_eckey_pubkey_serialize(&r, ptr, &pubkeylen, 1)) {
return 0;
}
secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_COMPRESSED);
ptr += pubkeylen;
*privkeylen = ptr - privkey;
} else {
@@ -165,45 +165,13 @@ static int secp256k1_eckey_privkey_serialize(const secp256k1_ecmult_gen_context
};
unsigned char *ptr = privkey;
memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
secp256k1_scalar_get_b32(ptr, key); ptr += 32;
memcpy(ptr, key32, 32); ptr += 32;
memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
if (!secp256k1_eckey_pubkey_serialize(&r, ptr, &pubkeylen, 0)) {
return 0;
}
secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_UNCOMPRESSED);
ptr += pubkeylen;
*privkeylen = ptr - privkey;
}
return 1;
}
static int secp256k1_ec_privkey_export_der(const secp256k1_context* ctx, unsigned char *privkey, size_t *privkeylen, const unsigned char *seckey, int compressed) {
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, compressed);
secp256k1_scalar_clear(&key);
return ret;
}
static int secp256k1_ec_privkey_import_der(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;
}
#endif