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ecmult_gen: Simplify ecmult_gen context after making table static

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This is a backwards-compatible API change: Before this commit, a context
initialized for signing was required to call functions that rely on
ecmult_gen. After this commit, this is no longer necessary because the
static ecmult_gen table is always present. In practice this means that
the corresponding functions will just work instead of calling the
illegal callback when given a context which is not (officially)
initialized for signing.

This is in line with 6815761, which made the analogous change with
respect to ecmult and contexts initialized for signing. But as opposed
to 681571, which removed the ecmult context entirely, we cannot remove
the ecmult_gen context entirely because it is still used for random
blinding. Moreover, since the secp256k1_context_no_precomp context is
const and cannot meaningfully support random blinding, we refrain (for
now) from changing its API, i.e., the illegal callback will still be
called when trying to use ecmult_gen operations with the static
secp256k1_context_no_precomp context.
This commit is contained in:
Tim Ruffing
2021-11-09 10:17:02 +01:00
parent e43ba02cfc
commit 3b0c2185ea
8 changed files with 109 additions and 101 deletions
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32
src/tests.c
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@@ -143,10 +143,12 @@ void run_context_tests(int use_prealloc) {
secp256k1_context *sign;
secp256k1_context *vrfy;
secp256k1_context *both;
secp256k1_context *sttc;
void *none_prealloc = NULL;
void *sign_prealloc = NULL;
void *vrfy_prealloc = NULL;
void *both_prealloc = NULL;
void *sttc_prealloc = NULL;
secp256k1_gej pubj;
secp256k1_ge pub;
@@ -158,26 +160,30 @@ void run_context_tests(int use_prealloc) {
sign_prealloc = malloc(secp256k1_context_preallocated_size(SECP256K1_CONTEXT_SIGN));
vrfy_prealloc = malloc(secp256k1_context_preallocated_size(SECP256K1_CONTEXT_VERIFY));
both_prealloc = malloc(secp256k1_context_preallocated_size(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY));
sttc_prealloc = malloc(secp256k1_context_preallocated_clone_size(secp256k1_context_no_precomp));
CHECK(none_prealloc != NULL);
CHECK(sign_prealloc != NULL);
CHECK(vrfy_prealloc != NULL);
CHECK(both_prealloc != NULL);
CHECK(sttc_prealloc != NULL);
none = secp256k1_context_preallocated_create(none_prealloc, SECP256K1_CONTEXT_NONE);
sign = secp256k1_context_preallocated_create(sign_prealloc, SECP256K1_CONTEXT_SIGN);
vrfy = secp256k1_context_preallocated_create(vrfy_prealloc, SECP256K1_CONTEXT_VERIFY);
both = secp256k1_context_preallocated_create(both_prealloc, SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY);
sttc = secp256k1_context_preallocated_clone(secp256k1_context_no_precomp, sttc_prealloc);
} else {
none = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
sign = secp256k1_context_create(SECP256K1_CONTEXT_SIGN);
vrfy = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY);
both = secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY);
sttc = secp256k1_context_clone(secp256k1_context_no_precomp);
}
memset(&zero_pubkey, 0, sizeof(zero_pubkey));
ecount = 0;
ecount2 = 10;
secp256k1_context_set_illegal_callback(vrfy, counting_illegal_callback_fn, &ecount);
secp256k1_context_set_illegal_callback(sttc, counting_illegal_callback_fn, &ecount);
secp256k1_context_set_illegal_callback(sign, counting_illegal_callback_fn, &ecount2);
/* set error callback (to a function that still aborts in case malloc() fails in secp256k1_context_clone() below) */
secp256k1_context_set_error_callback(sign, secp256k1_default_illegal_callback_fn, NULL);
@@ -189,6 +195,7 @@ void run_context_tests(int use_prealloc) {
CHECK(secp256k1_context_preallocated_clone_size(sign) == secp256k1_context_preallocated_size(SECP256K1_CONTEXT_SIGN));
CHECK(secp256k1_context_preallocated_clone_size(vrfy) == secp256k1_context_preallocated_size(SECP256K1_CONTEXT_VERIFY));
CHECK(secp256k1_context_preallocated_clone_size(both) == secp256k1_context_preallocated_size(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY));
CHECK(secp256k1_context_preallocated_clone_size(sttc) >= sizeof(secp256k1_context));
/*** clone and destroy all of them to make sure cloning was complete ***/
{
@@ -252,12 +259,12 @@ void run_context_tests(int use_prealloc) {
/* Verify context-type checking illegal-argument errors. */
memset(ctmp, 1, 32);
CHECK(secp256k1_ec_pubkey_create(vrfy, &pubkey, ctmp) == 0);
CHECK(secp256k1_ec_pubkey_create(sttc, &pubkey, ctmp) == 0);
CHECK(ecount == 1);
VG_UNDEF(&pubkey, sizeof(pubkey));
CHECK(secp256k1_ec_pubkey_create(sign, &pubkey, ctmp) == 1);
VG_CHECK(&pubkey, sizeof(pubkey));
CHECK(secp256k1_ecdsa_sign(vrfy, &sig, ctmp, ctmp, NULL, NULL) == 0);
CHECK(secp256k1_ecdsa_sign(sttc, &sig, ctmp, ctmp, NULL, NULL) == 0);
CHECK(ecount == 2);
VG_UNDEF(&sig, sizeof(sig));
CHECK(secp256k1_ecdsa_sign(sign, &sig, ctmp, ctmp, NULL, NULL) == 1);
@@ -265,33 +272,33 @@ void run_context_tests(int use_prealloc) {
CHECK(ecount2 == 10);
CHECK(secp256k1_ecdsa_verify(sign, &sig, ctmp, &pubkey) == 1);
CHECK(ecount2 == 10);
CHECK(secp256k1_ecdsa_verify(vrfy, &sig, ctmp, &pubkey) == 1);
CHECK(secp256k1_ecdsa_verify(sttc, &sig, ctmp, &pubkey) == 1);
CHECK(ecount == 2);
CHECK(secp256k1_ec_pubkey_tweak_add(sign, &pubkey, ctmp) == 1);
CHECK(ecount2 == 10);
CHECK(secp256k1_ec_pubkey_tweak_add(vrfy, &pubkey, ctmp) == 1);
CHECK(secp256k1_ec_pubkey_tweak_add(sttc, &pubkey, ctmp) == 1);
CHECK(ecount == 2);
CHECK(secp256k1_ec_pubkey_tweak_mul(sign, &pubkey, ctmp) == 1);
CHECK(ecount2 == 10);
CHECK(secp256k1_ec_pubkey_negate(vrfy, &pubkey) == 1);
CHECK(secp256k1_ec_pubkey_negate(sttc, &pubkey) == 1);
CHECK(ecount == 2);
CHECK(secp256k1_ec_pubkey_negate(sign, &pubkey) == 1);
CHECK(ecount == 2);
CHECK(secp256k1_ec_pubkey_negate(sign, NULL) == 0);
CHECK(ecount2 == 11);
CHECK(secp256k1_ec_pubkey_negate(vrfy, &zero_pubkey) == 0);
CHECK(secp256k1_ec_pubkey_negate(sttc, &zero_pubkey) == 0);
CHECK(ecount == 3);
CHECK(secp256k1_ec_pubkey_tweak_mul(vrfy, &pubkey, ctmp) == 1);
CHECK(secp256k1_ec_pubkey_tweak_mul(sttc, &pubkey, ctmp) == 1);
CHECK(ecount == 3);
CHECK(secp256k1_context_randomize(vrfy, ctmp) == 1);
CHECK(secp256k1_context_randomize(sttc, ctmp) == 1);
CHECK(ecount == 3);
CHECK(secp256k1_context_randomize(vrfy, NULL) == 1);
CHECK(secp256k1_context_randomize(sttc, NULL) == 1);
CHECK(ecount == 3);
CHECK(secp256k1_context_randomize(sign, ctmp) == 1);
CHECK(ecount2 == 11);
CHECK(secp256k1_context_randomize(sign, NULL) == 1);
CHECK(ecount2 == 11);
secp256k1_context_set_illegal_callback(vrfy, NULL, NULL);
secp256k1_context_set_illegal_callback(sttc, NULL, NULL);
secp256k1_context_set_illegal_callback(sign, NULL, NULL);
/* obtain a working nonce */
@@ -313,15 +320,18 @@ void run_context_tests(int use_prealloc) {
secp256k1_context_preallocated_destroy(sign);
secp256k1_context_preallocated_destroy(vrfy);
secp256k1_context_preallocated_destroy(both);
secp256k1_context_preallocated_destroy(sttc);
free(none_prealloc);
free(sign_prealloc);
free(vrfy_prealloc);
free(both_prealloc);
free(sttc_prealloc);
} else {
secp256k1_context_destroy(none);
secp256k1_context_destroy(sign);
secp256k1_context_destroy(vrfy);
secp256k1_context_destroy(both);
secp256k1_context_destroy(sttc);
}
/* Defined as no-op. */
secp256k1_context_destroy(NULL);