mleku/libsecp256k1
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Verify compressed argument in secp256k1_eckey_pubkey_serialize

Browse Source 
Due to similarity to the public API function `secp256k1_ec_pubkey_serialize`,
public API flags like `SECP256K1_EC_COMPRESSED` are sometimes mistakingly
passed to newly proposed code (this is currently the case for several modules in
secp256k1-zkp, see https://github.com/BlockstreamResearch/secp256k1-zkp/pull/300).
which is currently not detected. To avoid this in the future, a VERIFY_CHECK
is added to check that the `compressed` argument is either 0 or 1.
This commit is contained in:
Sebastian Falbesoner
2024-12-02 18:20:18 +01:00
parent 8deef00b33
commit 1823594761
2 changed files with 4 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
src/eckey_impl.h
View File

@@ -9,6 +9,7 @@
#include "eckey.h" #include "eckey.h"
#include "util.h"
#include "scalar.h" #include "scalar.h"
#include "field.h" #include "field.h"
#include "group.h" #include "group.h"
@@ -35,6 +36,8 @@ static int secp256k1_eckey_pubkey_parse(secp256k1_ge *elem, const unsigned char
} }
static int secp256k1_eckey_pubkey_serialize(secp256k1_ge *elem, unsigned char *pub, size_t *size, int compressed) { static int secp256k1_eckey_pubkey_serialize(secp256k1_ge *elem, unsigned char *pub, size_t *size, int compressed) {
VERIFY_CHECK(compressed == 0 || compressed == 1);
if (secp256k1_ge_is_infinity(elem)) { if (secp256k1_ge_is_infinity(elem)) {
return 0; return 0;
} }

2
src/secp256k1.c
View File

@@ -280,7 +280,7 @@ int secp256k1_ec_pubkey_serialize(const secp256k1_context* ctx, unsigned char *o
ARG_CHECK(pubkey != NULL); ARG_CHECK(pubkey != NULL);
ARG_CHECK((flags & SECP256K1_FLAGS_TYPE_MASK) == SECP256K1_FLAGS_TYPE_COMPRESSION); ARG_CHECK((flags & SECP256K1_FLAGS_TYPE_MASK) == SECP256K1_FLAGS_TYPE_COMPRESSION);
if (secp256k1_pubkey_load(ctx, &Q, pubkey)) { if (secp256k1_pubkey_load(ctx, &Q, pubkey)) {
ret = secp256k1_eckey_pubkey_serialize(&Q, output, &len, flags & SECP256K1_FLAGS_BIT_COMPRESSION); ret = secp256k1_eckey_pubkey_serialize(&Q, output, &len, !!(flags & SECP256K1_FLAGS_BIT_COMPRESSION));
if (ret) { if (ret) {
*outputlen = len; *outputlen = len;
} }