Align TRUST_TOKEN_pst_v1_voprf with draft-21 of VOPRF
This aligns the DLEQ proof portion of TRUST_TOKEN_pst_v1_voprf
with draft-irtf-cfrg-voprf-21. The blind and finalize operations
still differ. Additionally, as VOPRF doesn't include batched
issuance, the issuance process around the DLEQ proof is adapted
from draft-robert-privacypass-batched-tokens-01.
Bug: chromium:1414562
Change-Id: If1c6de0f92089a826968a57279ae598ccf89ca3e
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/58906
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/crypto/fipsmodule/ec/internal.h b/crypto/fipsmodule/ec/internal.h
index 846431f..3b6fa4a 100644
--- a/crypto/fipsmodule/ec/internal.h
+++ b/crypto/fipsmodule/ec/internal.h
@@ -91,6 +91,8 @@
// be the largest fields anyone plausibly uses.
#define EC_MAX_BYTES 66
#define EC_MAX_WORDS ((EC_MAX_BYTES + BN_BYTES - 1) / BN_BYTES)
+#define EC_MAX_COMPRESSED (EC_MAX_BYTES + 1)
+#define EC_MAX_UNCOMPRESSED (2 * EC_MAX_BYTES + 1)
static_assert(EC_MAX_WORDS <= BN_SMALL_MAX_WORDS,
"bn_*_small functions not usable");
@@ -119,8 +121,8 @@
// ec_scalar_from_bytes deserializes |in| and stores the resulting scalar over
// group |group| to |out|. It returns one on success and zero if |in| is
// invalid.
-int ec_scalar_from_bytes(const EC_GROUP *group, EC_SCALAR *out,
- const uint8_t *in, size_t len);
+OPENSSL_EXPORT int ec_scalar_from_bytes(const EC_GROUP *group, EC_SCALAR *out,
+ const uint8_t *in, size_t len);
// ec_scalar_reduce sets |out| to |words|, reduced modulo the group order.
// |words| must be less than order^2. |num| must be at most twice the width of
@@ -279,8 +281,8 @@
//
// If only extracting the x-coordinate, use |ec_get_x_coordinate_*| which is
// slightly faster.
-int ec_jacobian_to_affine(const EC_GROUP *group, EC_AFFINE *out,
- const EC_RAW_POINT *p);
+OPENSSL_EXPORT int ec_jacobian_to_affine(const EC_GROUP *group, EC_AFFINE *out,
+ const EC_RAW_POINT *p);
// ec_jacobian_to_affine_batch converts |num| points in |in| from Jacobian
// coordinates to affine coordinates and writes the results to |out|. It returns
diff --git a/crypto/trust_token/internal.h b/crypto/trust_token/internal.h
index e940565..8fc5d6e 100644
--- a/crypto/trust_token/internal.h
+++ b/crypto/trust_token/internal.h
@@ -239,6 +239,10 @@
int voprf_pst1_sign(const TRUST_TOKEN_ISSUER_KEY *key, CBB *cbb, CBS *cbs,
size_t num_requested, size_t num_to_issue,
uint8_t private_metadata);
+OPENSSL_EXPORT int voprf_pst1_sign_with_proof_scalar_for_testing(
+ const TRUST_TOKEN_ISSUER_KEY *key, CBB *cbb, CBS *cbs, size_t num_requested,
+ size_t num_to_issue, uint8_t private_metadata,
+ const uint8_t *proof_scalar_buf, size_t proof_scalar_len);
STACK_OF(TRUST_TOKEN) *voprf_pst1_unblind(
const TRUST_TOKEN_CLIENT_KEY *key,
const STACK_OF(TRUST_TOKEN_PRETOKEN) *pretokens, CBS *cbs, size_t count,
diff --git a/crypto/trust_token/trust_token_test.cc b/crypto/trust_token/trust_token_test.cc
index 376eacf..df679b6 100644
--- a/crypto/trust_token/trust_token_test.cc
+++ b/crypto/trust_token/trust_token_test.cc
@@ -314,6 +314,295 @@
EXPECT_EQ(Bytes(h), Bytes(expected_bytes, expected_len));
}
+static int ec_point_uncompressed_from_compressed(
+ const EC_GROUP *group, uint8_t out[EC_MAX_UNCOMPRESSED], size_t *out_len,
+ const uint8_t *in, size_t len) {
+ bssl::UniquePtr<EC_POINT> point(EC_POINT_new(group));
+ if (!point ||
+ !EC_POINT_oct2point(group, point.get(), in, len, nullptr)) {
+ return 0;
+ }
+
+ *out_len =
+ EC_POINT_point2oct(group, point.get(), POINT_CONVERSION_UNCOMPRESSED, out,
+ EC_MAX_UNCOMPRESSED, nullptr);
+ return 1;
+}
+
+static bool setup_voprf_test_key(const EC_GROUP *group,
+ TRUST_TOKEN_ISSUER_KEY *out) {
+ static const uint8_t kPrivateKey[] = {
+ 0x05, 0x16, 0x46, 0xb9, 0xe6, 0xe7, 0xa7, 0x1a, 0xe2, 0x7c, 0x1e, 0x1d,
+ 0x0b, 0x87, 0xb4, 0x38, 0x1d, 0xb6, 0xd3, 0x59, 0x5e, 0xee, 0xb1, 0xad,
+ 0xb4, 0x15, 0x79, 0xad, 0xbf, 0x99, 0x2f, 0x42, 0x78, 0xf9, 0x01, 0x6e,
+ 0xaf, 0xc9, 0x44, 0xed, 0xaa, 0x2b, 0x43, 0x18, 0x35, 0x81, 0x77, 0x9d
+ };
+
+ static const uint8_t kPublicKey[] = {
+ 0x03, 0x1d, 0x68, 0x96, 0x86, 0xc6, 0x11, 0x99, 0x1b, 0x55,
+ 0xf1, 0xa1, 0xd8, 0xf4, 0x30, 0x5c, 0xcd, 0x6c, 0xb7, 0x19,
+ 0x44, 0x6f, 0x66, 0x0a, 0x30, 0xdb, 0x61, 0xb7, 0xaa, 0x87,
+ 0xb4, 0x6a, 0xcf, 0x59, 0xb7, 0xc0, 0xd4, 0xa9, 0x07, 0x7b,
+ 0x3d, 0xa2, 0x1c, 0x25, 0xdd, 0x48, 0x22, 0x29, 0xa0
+ };
+
+ if (!ec_scalar_from_bytes(group, &out->xs, kPrivateKey,
+ sizeof(kPrivateKey))) {
+ return false;
+ }
+
+ bssl::UniquePtr<EC_POINT> pub(EC_POINT_new(group));
+ return pub &&
+ EC_POINT_oct2point(group, pub.get(), kPublicKey, sizeof(kPublicKey),
+ nullptr) &&
+ ec_jacobian_to_affine(group, &out->pubs, &pub->raw);
+}
+
+TEST(TrustTokenTest, PSTV1VOPRFTestVector1) {
+ const EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp384r1);
+ TRUST_TOKEN_ISSUER_KEY key;
+ ASSERT_TRUE(setup_voprf_test_key(group, &key));
+
+ static const uint8_t kBlindedElement[] = {
+ 0x02, 0xd3, 0x38, 0xc0, 0x5c, 0xbe, 0xcb, 0x82, 0xde, 0x13,
+ 0xd6, 0x70, 0x0f, 0x09, 0xcb, 0x61, 0x19, 0x05, 0x43, 0xa7,
+ 0xb7, 0xe2, 0xc6, 0xcd, 0x4f, 0xca, 0x56, 0x88, 0x7e, 0x56,
+ 0x4e, 0xa8, 0x26, 0x53, 0xb2, 0x7f, 0xda, 0xd3, 0x83, 0x99,
+ 0x5e, 0xa6, 0xd0, 0x2c, 0xf2, 0x6d, 0x0e, 0x24, 0xd9
+ };
+
+ static const uint8_t kEvaluatedElement[] = {
+ 0x02, 0xa7, 0xbb, 0xa5, 0x89, 0xb3, 0xe8, 0x67, 0x2a, 0xa1,
+ 0x9e, 0x8f, 0xd2, 0x58, 0xde, 0x2e, 0x6a, 0xae, 0x20, 0x10,
+ 0x1c, 0x8d, 0x76, 0x12, 0x46, 0xde, 0x97, 0xa6, 0xb5, 0xee,
+ 0x9c, 0xf1, 0x05, 0xfe, 0xbc, 0xe4, 0x32, 0x7a, 0x32, 0x62,
+ 0x55, 0xa3, 0xc6, 0x04, 0xf6, 0x3f, 0x60, 0x0e, 0xf6
+ };
+
+ static const uint8_t kProof[] = {
+ 0xbf, 0xc6, 0xcf, 0x38, 0x59, 0x12, 0x7f, 0x5f, 0xe2, 0x55, 0x48, 0x85,
+ 0x98, 0x56, 0xd6, 0xb7, 0xfa, 0x1c, 0x74, 0x59, 0xf0, 0xba, 0x57, 0x12,
+ 0xa8, 0x06, 0xfc, 0x09, 0x1a, 0x30, 0x00, 0xc4, 0x2d, 0x8b, 0xa3, 0x4f,
+ 0xf4, 0x5f, 0x32, 0xa5, 0x2e, 0x40, 0x53, 0x3e, 0xfd, 0x2a, 0x03, 0xbc,
+ 0x87, 0xf3, 0xbf, 0x4f, 0x9f, 0x58, 0x02, 0x82, 0x97, 0xcc, 0xb9, 0xcc,
+ 0xb1, 0x8a, 0xe7, 0x18, 0x2b, 0xcd, 0x1e, 0xf2, 0x39, 0xdf, 0x77, 0xe3,
+ 0xbe, 0x65, 0xef, 0x14, 0x7f, 0x3a, 0xcf, 0x8b, 0xc9, 0xcb, 0xfc, 0x55,
+ 0x24, 0xb7, 0x02, 0x26, 0x34, 0x14, 0xf0, 0x43, 0xe3, 0xb7, 0xca, 0x2e
+ };
+
+ static const uint8_t kProofScalar[] = {
+ 0x80, 0x3d, 0x95, 0x5f, 0x0e, 0x07, 0x3a, 0x04, 0xaa, 0x5d, 0x92, 0xb3,
+ 0xfb, 0x73, 0x9f, 0x56, 0xf9, 0xdb, 0x00, 0x12, 0x66, 0x67, 0x7f, 0x62,
+ 0xc0, 0x95, 0x02, 0x1d, 0xb0, 0x18, 0xcd, 0x8c, 0xbb, 0x55, 0x94, 0x1d,
+ 0x40, 0x73, 0x69, 0x8c, 0xe4, 0x5c, 0x40, 0x5d, 0x13, 0x48, 0xb7, 0xb1
+ };
+
+ uint8_t blinded_buf[EC_MAX_UNCOMPRESSED];
+ size_t blinded_len;
+ ASSERT_TRUE(ec_point_uncompressed_from_compressed(
+ group, blinded_buf, &blinded_len, kBlindedElement,
+ sizeof(kBlindedElement)));
+
+ CBS sign_input;
+ CBS_init(&sign_input, blinded_buf, blinded_len);
+ bssl::ScopedCBB response;
+ ASSERT_TRUE(CBB_init(response.get(), 0));
+ ASSERT_TRUE(voprf_pst1_sign_with_proof_scalar_for_testing(
+ &key, response.get(), &sign_input, /*num_requested=*/1,
+ /*num_to_issue=*/1,
+ /*private_metadata=*/0, kProofScalar, sizeof(kProofScalar)));
+
+ uint8_t evaluated_buf[EC_MAX_UNCOMPRESSED];
+ size_t evaluated_len;
+ ASSERT_TRUE(ec_point_uncompressed_from_compressed(
+ group, evaluated_buf, &evaluated_len, kEvaluatedElement,
+ sizeof(kEvaluatedElement)));
+
+ bssl::ScopedCBB expected_response;
+ ASSERT_TRUE(CBB_init(expected_response.get(), 0));
+ ASSERT_TRUE(
+ CBB_add_bytes(expected_response.get(), evaluated_buf, evaluated_len));
+ ASSERT_TRUE(CBB_add_u16(expected_response.get(), sizeof(kProof)));
+ ASSERT_TRUE(CBB_add_bytes(expected_response.get(), kProof, sizeof(kProof)));
+ ASSERT_TRUE(CBB_flush(expected_response.get()));
+
+ ASSERT_EQ(Bytes(CBB_data(expected_response.get()),
+ CBB_len(expected_response.get())),
+ Bytes(CBB_data(response.get()), CBB_len(response.get())));
+}
+
+TEST(TrustTokenTest, PSTV1VOPRFTestVector2) {
+ const EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp384r1);
+ TRUST_TOKEN_ISSUER_KEY key;
+ ASSERT_TRUE(setup_voprf_test_key(group, &key));
+
+ static const uint8_t kBlindedElement[] = {
+ 0x02, 0xf2, 0x74, 0x69, 0xe0, 0x59, 0x88, 0x6f, 0x22, 0x1b,
+ 0xe5, 0xf2, 0xcc, 0xa0, 0x3d, 0x2b, 0xdc, 0x61, 0xe5, 0x52,
+ 0x21, 0x72, 0x1c, 0x3b, 0x3e, 0x56, 0xfc, 0x01, 0x2e, 0x36,
+ 0xd3, 0x1a, 0xe5, 0xf8, 0xdc, 0x05, 0x81, 0x09, 0x59, 0x15,
+ 0x56, 0xa6, 0xdb, 0xd3, 0xa8, 0xc6, 0x9c, 0x43, 0x3b
+ };
+
+ static const uint8_t kEvaluatedElement[] = {
+ 0x03, 0xf1, 0x6f, 0x90, 0x39, 0x47, 0x03, 0x54, 0x00, 0xe9,
+ 0x6b, 0x7f, 0x53, 0x1a, 0x38, 0xd4, 0xa0, 0x7a, 0xc8, 0x9a,
+ 0x80, 0xf8, 0x9d, 0x86, 0xa1, 0xbf, 0x08, 0x9c, 0x52, 0x5a,
+ 0x92, 0xc7, 0xf4, 0x73, 0x37, 0x29, 0xca, 0x30, 0xc5, 0x6c,
+ 0xe7, 0x8b, 0x1a, 0xb4, 0xf7, 0xd9, 0x2d, 0xb8, 0xb4
+ };
+
+ static const uint8_t kProof[] = {
+ 0xd0, 0x05, 0xd6, 0xda, 0xaa, 0xd7, 0x57, 0x14, 0x14, 0xc1, 0xe0,
+ 0xc7, 0x5f, 0x7e, 0x57, 0xf2, 0x11, 0x3c, 0xa9, 0xf4, 0x60, 0x4e,
+ 0x84, 0xbc, 0x90, 0xf9, 0xbe, 0x52, 0xda, 0x89, 0x6f, 0xff, 0x3b,
+ 0xee, 0x49, 0x6d, 0xcd, 0xe2, 0xa5, 0x78, 0xae, 0x9d, 0xf3, 0x15,
+ 0x03, 0x25, 0x85, 0xf8, 0x01, 0xfb, 0x21, 0xc6, 0x08, 0x0a, 0xc0,
+ 0x56, 0x72, 0xb2, 0x91, 0xe5, 0x75, 0xa4, 0x02, 0x95, 0xb3, 0x06,
+ 0xd9, 0x67, 0x71, 0x7b, 0x28, 0xe0, 0x8f, 0xcc, 0x8a, 0xd1, 0xca,
+ 0xb4, 0x78, 0x45, 0xd1, 0x6a, 0xf7, 0x3b, 0x3e, 0x64, 0x3d, 0xdc,
+ 0xc1, 0x91, 0x20, 0x8e, 0x71, 0xc6, 0x46, 0x30
+ };
+
+ static const uint8_t kProofScalar[] = {
+ 0x80, 0x3d, 0x95, 0x5f, 0x0e, 0x07, 0x3a, 0x04, 0xaa, 0x5d, 0x92, 0xb3,
+ 0xfb, 0x73, 0x9f, 0x56, 0xf9, 0xdb, 0x00, 0x12, 0x66, 0x67, 0x7f, 0x62,
+ 0xc0, 0x95, 0x02, 0x1d, 0xb0, 0x18, 0xcd, 0x8c, 0xbb, 0x55, 0x94, 0x1d,
+ 0x40, 0x73, 0x69, 0x8c, 0xe4, 0x5c, 0x40, 0x5d, 0x13, 0x48, 0xb7, 0xb1
+ };
+
+ uint8_t blinded_buf[EC_MAX_UNCOMPRESSED];
+ size_t blinded_len;
+ ASSERT_TRUE(ec_point_uncompressed_from_compressed(
+ group, blinded_buf, &blinded_len, kBlindedElement,
+ sizeof(kBlindedElement)));
+
+ CBS sign_input;
+ CBS_init(&sign_input, blinded_buf, blinded_len);
+ bssl::ScopedCBB response;
+ ASSERT_TRUE(CBB_init(response.get(), 0));
+ ASSERT_TRUE(voprf_pst1_sign_with_proof_scalar_for_testing(
+ &key, response.get(), &sign_input, /*num_requested=*/1,
+ /*num_to_issue=*/1,
+ /*private_metadata=*/0, kProofScalar, sizeof(kProofScalar)));
+
+ uint8_t evaluated_buf[EC_MAX_UNCOMPRESSED];
+ size_t evaluated_len;
+ ASSERT_TRUE(ec_point_uncompressed_from_compressed(
+ group, evaluated_buf, &evaluated_len, kEvaluatedElement,
+ sizeof(kEvaluatedElement)));
+
+ bssl::ScopedCBB expected_response;
+ ASSERT_TRUE(CBB_init(expected_response.get(), 0));
+ ASSERT_TRUE(
+ CBB_add_bytes(expected_response.get(), evaluated_buf, evaluated_len));
+ ASSERT_TRUE(CBB_add_u16(expected_response.get(), sizeof(kProof)));
+ ASSERT_TRUE(CBB_add_bytes(expected_response.get(), kProof, sizeof(kProof)));
+ ASSERT_TRUE(CBB_flush(expected_response.get()));
+
+ ASSERT_EQ(Bytes(CBB_data(expected_response.get()),
+ CBB_len(expected_response.get())),
+ Bytes(CBB_data(response.get()), CBB_len(response.get())));
+}
+
+TEST(TrustTokenTest, PSTV1VOPRFTestVector3) {
+ const EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp384r1);
+ TRUST_TOKEN_ISSUER_KEY key;
+ ASSERT_TRUE(setup_voprf_test_key(group, &key));
+
+ static const uint8_t kBlindedElement1[] = {
+ 0x02, 0xd3, 0x38, 0xc0, 0x5c, 0xbe, 0xcb, 0x82, 0xde, 0x13,
+ 0xd6, 0x70, 0x0f, 0x09, 0xcb, 0x61, 0x19, 0x05, 0x43, 0xa7,
+ 0xb7, 0xe2, 0xc6, 0xcd, 0x4f, 0xca, 0x56, 0x88, 0x7e, 0x56,
+ 0x4e, 0xa8, 0x26, 0x53, 0xb2, 0x7f, 0xda, 0xd3, 0x83, 0x99,
+ 0x5e, 0xa6, 0xd0, 0x2c, 0xf2, 0x6d, 0x0e, 0x24, 0xd9
+ };
+ static const uint8_t kBlindedElement2[] = {
+ 0x02, 0xfa, 0x02, 0x47, 0x0d, 0x7f, 0x15, 0x10, 0x18, 0xb4,
+ 0x1e, 0x82, 0x22, 0x3c, 0x32, 0xfa, 0xd8, 0x24, 0xde, 0x6a,
+ 0xd4, 0xb5, 0xce, 0x9f, 0x8e, 0x9f, 0x98, 0x08, 0x3c, 0x9a,
+ 0x72, 0x6d, 0xe9, 0xa1, 0xfc, 0x39, 0xd7, 0xa0, 0xcb, 0x6f,
+ 0x4f, 0x18, 0x8d, 0xd9, 0xce, 0xa0, 0x14, 0x74, 0xcd
+ };
+
+ static const uint8_t kEvaluatedElement1[] = {
+ 0x02, 0xa7, 0xbb, 0xa5, 0x89, 0xb3, 0xe8, 0x67, 0x2a, 0xa1,
+ 0x9e, 0x8f, 0xd2, 0x58, 0xde, 0x2e, 0x6a, 0xae, 0x20, 0x10,
+ 0x1c, 0x8d, 0x76, 0x12, 0x46, 0xde, 0x97, 0xa6, 0xb5, 0xee,
+ 0x9c, 0xf1, 0x05, 0xfe, 0xbc, 0xe4, 0x32, 0x7a, 0x32, 0x62,
+ 0x55, 0xa3, 0xc6, 0x04, 0xf6, 0x3f, 0x60, 0x0e, 0xf6
+ };
+
+ static const uint8_t kEvaluatedElement2[] = {
+ 0x02, 0x8e, 0x9e, 0x11, 0x56, 0x25, 0xff, 0x4c, 0x2f, 0x07,
+ 0xbf, 0x87, 0xce, 0x3f, 0xd7, 0x3f, 0xc7, 0x79, 0x94, 0xa7,
+ 0xa0, 0xc1, 0xdf, 0x03, 0xd2, 0xa6, 0x30, 0xa3, 0xd8, 0x45,
+ 0x93, 0x0e, 0x2e, 0x63, 0xa1, 0x65, 0xb1, 0x14, 0xd9, 0x8f,
+ 0xe3, 0x4e, 0x61, 0xb6, 0x8d, 0x23, 0xc0, 0xb5, 0x0a
+ };
+
+ static const uint8_t kProof[] = {
+ 0x6d, 0x8d, 0xcb, 0xd2, 0xfc, 0x95, 0x55, 0x0a, 0x02, 0x21, 0x1f,
+ 0xb7, 0x8a, 0xfd, 0x01, 0x39, 0x33, 0xf3, 0x07, 0xd2, 0x1e, 0x7d,
+ 0x85, 0x5b, 0x0b, 0x1e, 0xd0, 0xaf, 0x78, 0x07, 0x6d, 0x81, 0x37,
+ 0xad, 0x8b, 0x0a, 0x1b, 0xfa, 0x05, 0x67, 0x6d, 0x32, 0x52, 0x49,
+ 0xc1, 0xdb, 0xb9, 0xa5, 0x2b, 0xd8, 0x1b, 0x1c, 0x2b, 0x7b, 0x0e,
+ 0xfc, 0x77, 0xcf, 0x7b, 0x27, 0x8e, 0x1c, 0x94, 0x7f, 0x62, 0x83,
+ 0xf1, 0xd4, 0xc5, 0x13, 0x05, 0x3f, 0xc0, 0xad, 0x19, 0xe0, 0x26,
+ 0xfb, 0x0c, 0x30, 0x65, 0x4b, 0x53, 0xd9, 0xce, 0xa4, 0xb8, 0x7b,
+ 0x03, 0x72, 0x71, 0xb5, 0xd2, 0xe2, 0xd0, 0xea
+ };
+
+ static const uint8_t kProofScalar[] = {
+ 0xa0, 0x97, 0xe7, 0x22, 0xed, 0x24, 0x27, 0xde, 0x86, 0x96,
+ 0x69, 0x10, 0xac, 0xba, 0x9f, 0x5c, 0x35, 0x0e, 0x80, 0x40,
+ 0xf8, 0x28, 0xbf, 0x6c, 0xec, 0xa2, 0x74, 0x05, 0x42, 0x0c,
+ 0xdf, 0x3d, 0x63, 0xcb, 0x3a, 0xef, 0x00, 0x5f, 0x40, 0xba,
+ 0x51, 0x94, 0x3c, 0x80, 0x26, 0x87, 0x79, 0x63
+ };
+
+ uint8_t blinded_buf[2*EC_MAX_UNCOMPRESSED];
+ size_t blinded_len;
+ ASSERT_TRUE(ec_point_uncompressed_from_compressed(
+ group, blinded_buf, &blinded_len, kBlindedElement1,
+ sizeof(kBlindedElement1)));
+ size_t offset = blinded_len;
+ ASSERT_TRUE(ec_point_uncompressed_from_compressed(
+ group, blinded_buf + offset, &blinded_len, kBlindedElement2,
+ sizeof(kBlindedElement2)));
+
+ CBS sign_input;
+ CBS_init(&sign_input, blinded_buf, offset + blinded_len);
+ bssl::ScopedCBB response;
+ ASSERT_TRUE(CBB_init(response.get(), 0));
+ ASSERT_TRUE(voprf_pst1_sign_with_proof_scalar_for_testing(
+ &key, response.get(), &sign_input, /*num_requested=*/2,
+ /*num_to_issue=*/2,
+ /*private_metadata=*/0, kProofScalar, sizeof(kProofScalar)));
+
+ uint8_t evaluated_buf[2 * EC_MAX_UNCOMPRESSED];
+ size_t evaluated_len;
+ ASSERT_TRUE(ec_point_uncompressed_from_compressed(
+ group, evaluated_buf, &evaluated_len, kEvaluatedElement1,
+ sizeof(kEvaluatedElement1)));
+ offset = evaluated_len;
+ ASSERT_TRUE(ec_point_uncompressed_from_compressed(
+ group, evaluated_buf + offset, &evaluated_len, kEvaluatedElement2,
+ sizeof(kEvaluatedElement2)));
+
+ bssl::ScopedCBB expected_response;
+ ASSERT_TRUE(CBB_init(expected_response.get(), 0));
+ ASSERT_TRUE(CBB_add_bytes(expected_response.get(), evaluated_buf,
+ offset + evaluated_len));
+ ASSERT_TRUE(CBB_add_u16(expected_response.get(), sizeof(kProof)));
+ ASSERT_TRUE(CBB_add_bytes(expected_response.get(), kProof, sizeof(kProof)));
+ ASSERT_TRUE(CBB_flush(expected_response.get()));
+
+ ASSERT_EQ(Bytes(CBB_data(expected_response.get()),
+ CBB_len(expected_response.get())),
+ Bytes(CBB_data(response.get()), CBB_len(response.get())));
+}
+
static std::vector<const TRUST_TOKEN_METHOD *> AllMethods() {
return {
TRUST_TOKEN_experiment_v1(),
diff --git a/crypto/trust_token/voprf.c b/crypto/trust_token/voprf.c
index d414bfd..aa7df8e 100644
--- a/crypto/trust_token/voprf.c
+++ b/crypto/trust_token/voprf.c
@@ -63,18 +63,24 @@
static int cbb_add_point(CBB *out, const EC_GROUP *group,
const EC_AFFINE *point) {
- size_t len = ec_point_byte_len(group, POINT_CONVERSION_UNCOMPRESSED);
- if (len == 0) {
- return 0;
- }
-
uint8_t *p;
+ size_t len = ec_point_byte_len(group, POINT_CONVERSION_UNCOMPRESSED);
return CBB_add_space(out, &p, len) &&
ec_point_to_bytes(group, point, POINT_CONVERSION_UNCOMPRESSED, p,
len) == len &&
CBB_flush(out);
}
+static int cbb_serialize_point(CBB *out, const EC_GROUP *group,
+ const EC_AFFINE *point) {
+ uint8_t *p;
+ size_t len = ec_point_byte_len(group, POINT_CONVERSION_COMPRESSED);
+ return CBB_add_u16(out, len) && CBB_add_space(out, &p, len) &&
+ ec_point_to_bytes(group, point, POINT_CONVERSION_COMPRESSED, p, len) ==
+ len &&
+ CBB_flush(out);
+}
+
static int cbs_get_point(CBS *cbs, const EC_GROUP *group, EC_AFFINE *out) {
CBS child;
size_t plen = 1 + 2 * BN_num_bytes(&group->field);
@@ -299,6 +305,30 @@
return ok;
}
+static int hash_to_scalar_challenge(const VOPRF_METHOD *method, EC_SCALAR *out,
+ const EC_AFFINE *Bm, const EC_AFFINE *a0,
+ const EC_AFFINE *a1, const EC_AFFINE *a2,
+ const EC_AFFINE *a3) {
+ static const uint8_t kChallengeLabel[] = "Challenge";
+
+ CBB cbb;
+ uint8_t transcript[5 * EC_MAX_COMPRESSED + 2 + sizeof(kChallengeLabel) - 1];
+ size_t len;
+ if (!CBB_init_fixed(&cbb, transcript, sizeof(transcript)) ||
+ !cbb_serialize_point(&cbb, method->group, Bm) ||
+ !cbb_serialize_point(&cbb, method->group, a0) ||
+ !cbb_serialize_point(&cbb, method->group, a1) ||
+ !cbb_serialize_point(&cbb, method->group, a2) ||
+ !cbb_serialize_point(&cbb, method->group, a3) ||
+ !CBB_add_bytes(&cbb, kChallengeLabel, sizeof(kChallengeLabel) - 1) ||
+ !CBB_finish(&cbb, NULL, &len) ||
+ !method->hash_to_scalar(method->group, out, transcript, len)) {
+ return 0;
+ }
+
+ return 1;
+}
+
static int hash_to_scalar_batch(const VOPRF_METHOD *method, EC_SCALAR *out,
const CBB *points, size_t index) {
static const uint8_t kDLEQBatchLabel[] = "DLEQ BATCH";
@@ -455,9 +485,9 @@
return 1;
}
-static int voprf_sign(const VOPRF_METHOD *method,
- const TRUST_TOKEN_ISSUER_KEY *key, CBB *cbb, CBS *cbs,
- size_t num_requested, size_t num_to_issue) {
+static int voprf_sign_tt(const VOPRF_METHOD *method,
+ const TRUST_TOKEN_ISSUER_KEY *key, CBB *cbb, CBS *cbs,
+ size_t num_requested, size_t num_to_issue) {
const EC_GROUP *group = method->group;
if (num_requested < num_to_issue) {
OPENSSL_PUT_ERROR(TRUST_TOKEN, ERR_R_INTERNAL_ERROR);
@@ -553,7 +583,7 @@
return ret;
}
-static STACK_OF(TRUST_TOKEN) *voprf_unblind(
+static STACK_OF(TRUST_TOKEN) *voprf_unblind_tt(
const VOPRF_METHOD *method, const TRUST_TOKEN_CLIENT_KEY *key,
const STACK_OF(TRUST_TOKEN_PRETOKEN) *pretokens, CBS *cbs, size_t count,
uint32_t key_id) {
@@ -673,6 +703,397 @@
return ret;
}
+static void sha384_update_u16(SHA512_CTX *ctx, uint16_t v) {
+ uint8_t buf[2] = {v >> 8, v & 0xff};
+ SHA384_Update(ctx, buf, 2);
+}
+
+static void sha384_update_point_with_length(
+ SHA512_CTX *ctx, const EC_GROUP *group, const EC_AFFINE *point) {
+ uint8_t buf[EC_MAX_COMPRESSED];
+ size_t len = ec_point_to_bytes(group, point, POINT_CONVERSION_COMPRESSED,
+ buf, sizeof(buf));
+ assert(len > 0);
+ sha384_update_u16(ctx, (uint16_t)len);
+ SHA384_Update(ctx, buf, len);
+}
+
+static int compute_composite_seed(const VOPRF_METHOD *method,
+ uint8_t out[SHA384_DIGEST_LENGTH],
+ const EC_AFFINE *pub) {
+ const EC_GROUP *group = method->group;
+ static const uint8_t kSeedDST[] = "Seed-OPRFV1-\x01-P384-SHA384";
+
+ SHA512_CTX hash_ctx;
+ SHA384_Init(&hash_ctx);
+ sha384_update_point_with_length(&hash_ctx, group, pub);
+ sha384_update_u16(&hash_ctx, sizeof(kSeedDST) - 1);
+ SHA384_Update(&hash_ctx, kSeedDST, sizeof(kSeedDST) - 1);
+ SHA384_Final(out, &hash_ctx);
+
+ return 1;
+}
+
+static int compute_composite_element(const VOPRF_METHOD *method,
+ uint8_t seed[SHA384_DIGEST_LENGTH],
+ EC_SCALAR *di, size_t index,
+ const EC_AFFINE *C, const EC_AFFINE *D) {
+ static const uint8_t kCompositeLabel[] = "Composite";
+ const EC_GROUP *group = method->group;
+
+ if (index > UINT16_MAX) {
+ return 0;
+ }
+
+ CBB cbb;
+ uint8_t transcript[2 + SHA384_DIGEST_LENGTH + 2 + 2 * EC_MAX_COMPRESSED +
+ sizeof(kCompositeLabel) - 1];
+ size_t len;
+ if (!CBB_init_fixed(&cbb, transcript, sizeof(transcript)) ||
+ !CBB_add_u16(&cbb, SHA384_DIGEST_LENGTH) ||
+ !CBB_add_bytes(&cbb, seed, SHA384_DIGEST_LENGTH) ||
+ !CBB_add_u16(&cbb, index) ||
+ !cbb_serialize_point(&cbb, group, C) ||
+ !cbb_serialize_point(&cbb, group, D) ||
+ !CBB_add_bytes(&cbb, kCompositeLabel,
+ sizeof(kCompositeLabel) - 1) ||
+ !CBB_finish(&cbb, NULL, &len) ||
+ !method->hash_to_scalar(method->group, di, transcript, len)) {
+ return 0;
+ }
+
+ return 1;
+}
+
+static int generate_proof(const VOPRF_METHOD *method, CBB *cbb,
+ const TRUST_TOKEN_ISSUER_KEY *priv,
+ const EC_SCALAR *r, const EC_RAW_POINT *M,
+ const EC_RAW_POINT *Z) {
+ const EC_GROUP *group = method->group;
+
+ enum {
+ idx_M,
+ idx_Z,
+ idx_t2,
+ idx_t3,
+ num_idx,
+ };
+ EC_RAW_POINT jacobians[num_idx];
+
+ if (!ec_point_mul_scalar_base(group, &jacobians[idx_t2], r) ||
+ !ec_point_mul_scalar(group, &jacobians[idx_t3], M, r)) {
+ return 0;
+ }
+
+
+ EC_AFFINE affines[num_idx];
+ jacobians[idx_M] = *M;
+ jacobians[idx_Z] = *Z;
+ if (!ec_jacobian_to_affine_batch(group, affines, jacobians, num_idx)) {
+ return 0;
+ }
+
+ EC_SCALAR c;
+ if (!hash_to_scalar_challenge(method, &c, &priv->pubs, &affines[idx_M],
+ &affines[idx_Z], &affines[idx_t2],
+ &affines[idx_t3])) {
+ return 0;
+ }
+
+ EC_SCALAR c_mont;
+ ec_scalar_to_montgomery(group, &c_mont, &c);
+
+ // s = r - c*xs
+ EC_SCALAR s;
+ ec_scalar_mul_montgomery(group, &s, &priv->xs, &c_mont);
+ ec_scalar_sub(group, &s, r, &s);
+
+ // Store DLEQ proof in transcript.
+ if (!scalar_to_cbb(cbb, group, &c) ||
+ !scalar_to_cbb(cbb, group, &s)) {
+ return 0;
+ }
+
+ return 1;
+}
+
+static int verify_proof(const VOPRF_METHOD *method, CBS *cbs,
+ const TRUST_TOKEN_CLIENT_KEY *pub,
+ const EC_RAW_POINT *M, const EC_RAW_POINT *Z) {
+ const EC_GROUP *group = method->group;
+
+ enum {
+ idx_M,
+ idx_Z,
+ idx_t2,
+ idx_t3,
+ num_idx,
+ };
+ EC_RAW_POINT jacobians[num_idx];
+
+ EC_SCALAR c, s;
+ if (!scalar_from_cbs(cbs, group, &c) ||
+ !scalar_from_cbs(cbs, group, &s)) {
+ OPENSSL_PUT_ERROR(TRUST_TOKEN, TRUST_TOKEN_R_DECODE_FAILURE);
+ return 0;
+ }
+
+ EC_RAW_POINT pubs;
+ ec_affine_to_jacobian(group, &pubs, &pub->pubs);
+ if (!ec_point_mul_scalar_public(group, &jacobians[idx_t2], &s, &pubs,
+ &c) ||
+ !mul_public_2(group, &jacobians[idx_t3], M, &s, Z, &c)) {
+ return 0;
+ }
+
+ EC_AFFINE affines[num_idx];
+ jacobians[idx_M] = *M;
+ jacobians[idx_Z] = *Z;
+ if (!ec_jacobian_to_affine_batch(group, affines, jacobians, num_idx)) {
+ return 0;
+ }
+
+ EC_SCALAR expected_c;
+ if (!hash_to_scalar_challenge(method, &expected_c, &pub->pubs,
+ &affines[idx_M], &affines[idx_Z],
+ &affines[idx_t2], &affines[idx_t3])) {
+ return 0;
+ }
+
+ // c == expected_c
+ if (!ec_scalar_equal_vartime(group, &c, &expected_c)) {
+ OPENSSL_PUT_ERROR(TRUST_TOKEN, TRUST_TOKEN_R_INVALID_PROOF);
+ return 0;
+ }
+
+ return 1;
+}
+
+static int voprf_sign_impl(const VOPRF_METHOD *method,
+ const TRUST_TOKEN_ISSUER_KEY *key, CBB *cbb,
+ CBS *cbs, size_t num_requested, size_t num_to_issue,
+ const EC_SCALAR *proof_scalar) {
+ const EC_GROUP *group = method->group;
+ if (num_requested < num_to_issue) {
+ OPENSSL_PUT_ERROR(TRUST_TOKEN, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+
+ if (num_to_issue > ((size_t)-1) / sizeof(EC_RAW_POINT) ||
+ num_to_issue > ((size_t)-1) / sizeof(EC_SCALAR)) {
+ OPENSSL_PUT_ERROR(TRUST_TOKEN, ERR_R_OVERFLOW);
+ return 0;
+ }
+
+ int ret = 0;
+ EC_RAW_POINT *BTs = OPENSSL_malloc(num_to_issue * sizeof(EC_RAW_POINT));
+ EC_RAW_POINT *Zs = OPENSSL_malloc(num_to_issue * sizeof(EC_RAW_POINT));
+ EC_SCALAR *dis = OPENSSL_malloc(num_to_issue * sizeof(EC_SCALAR));
+ if (!BTs || !Zs || !dis) {
+ goto err;
+ }
+
+ uint8_t seed[SHA384_DIGEST_LENGTH];
+ if (!compute_composite_seed(method, seed, &key->pubs)) {
+ goto err;
+ }
+
+ // This implements the BlindEvaluateBatch as defined in section 4 of
+ // draft-robert-privacypass-batched-tokens-01, based on the constructions
+ // in draft-irtf-cfrg-voprf-21. To optimize the computation of the proof,
+ // the computation of di is done during the token signing and passed into
+ // the proof generation.
+ for (size_t i = 0; i < num_to_issue; i++) {
+ EC_AFFINE BT_affine, Z_affine;
+ EC_RAW_POINT BT, Z;
+ if (!cbs_get_point(cbs, group, &BT_affine)) {
+ OPENSSL_PUT_ERROR(TRUST_TOKEN, TRUST_TOKEN_R_DECODE_FAILURE);
+ goto err;
+ }
+ ec_affine_to_jacobian(group, &BT, &BT_affine);
+ if (!ec_point_mul_scalar(group, &Z, &BT, &key->xs) ||
+ !ec_jacobian_to_affine(group, &Z_affine, &Z) ||
+ !cbb_add_point(cbb, group, &Z_affine)) {
+ goto err;
+ }
+ BTs[i] = BT;
+ Zs[i] = Z;
+ if (!compute_composite_element(method, seed, &dis[i], i, &BT_affine,
+ &Z_affine)) {
+ goto err;
+ }
+
+ if (!CBB_flush(cbb)) {
+ goto err;
+ }
+ }
+
+ EC_RAW_POINT M, Z;
+ if (!ec_point_mul_scalar_public_batch(group, &M,
+ /*g_scalar=*/NULL, BTs, dis,
+ num_to_issue) ||
+ !ec_point_mul_scalar(group, &Z, &M, &key->xs)) {
+ goto err;
+ }
+
+ CBB proof;
+ if (!CBB_add_u16_length_prefixed(cbb, &proof) ||
+ !generate_proof(method, &proof, key, proof_scalar, &M, &Z) ||
+ !CBB_flush(cbb)) {
+ goto err;
+ }
+
+ // Skip over any unused requests.
+ size_t point_len = 1 + 2 * BN_num_bytes(&group->field);
+ if (!CBS_skip(cbs, point_len * (num_requested - num_to_issue))) {
+ OPENSSL_PUT_ERROR(TRUST_TOKEN, TRUST_TOKEN_R_DECODE_FAILURE);
+ goto err;
+ }
+
+ ret = 1;
+
+err:
+ OPENSSL_free(BTs);
+ OPENSSL_free(Zs);
+ OPENSSL_free(dis);
+ return ret;
+}
+
+static int voprf_sign(const VOPRF_METHOD *method,
+ const TRUST_TOKEN_ISSUER_KEY *key, CBB *cbb, CBS *cbs,
+ size_t num_requested, size_t num_to_issue) {
+ EC_SCALAR proof_scalar;
+ if (!ec_random_nonzero_scalar(method->group, &proof_scalar,
+ kDefaultAdditionalData)) {
+ return 0;
+ }
+
+ return voprf_sign_impl(method, key, cbb, cbs, num_requested, num_to_issue,
+ &proof_scalar);
+}
+
+static int voprf_sign_with_proof_scalar_for_testing(
+ const VOPRF_METHOD *method, const TRUST_TOKEN_ISSUER_KEY *key, CBB *cbb,
+ CBS *cbs, size_t num_requested, size_t num_to_issue,
+ const uint8_t *proof_scalar_buf, size_t proof_scalar_len) {
+ EC_SCALAR proof_scalar;
+ if (!ec_scalar_from_bytes(method->group, &proof_scalar, proof_scalar_buf,
+ proof_scalar_len)) {
+ return 0;
+ }
+ return voprf_sign_impl(method, key, cbb, cbs, num_requested, num_to_issue,
+ &proof_scalar);
+}
+
+static STACK_OF(TRUST_TOKEN) *voprf_unblind(
+ const VOPRF_METHOD *method, const TRUST_TOKEN_CLIENT_KEY *key,
+ const STACK_OF(TRUST_TOKEN_PRETOKEN) *pretokens, CBS *cbs, size_t count,
+ uint32_t key_id) {
+ const EC_GROUP *group = method->group;
+ if (count > sk_TRUST_TOKEN_PRETOKEN_num(pretokens)) {
+ OPENSSL_PUT_ERROR(TRUST_TOKEN, TRUST_TOKEN_R_DECODE_FAILURE);
+ return NULL;
+ }
+
+ if (count > ((size_t)-1) / sizeof(EC_RAW_POINT) ||
+ count > ((size_t)-1) / sizeof(EC_SCALAR)) {
+ OPENSSL_PUT_ERROR(TRUST_TOKEN, ERR_R_OVERFLOW);
+ return NULL;
+ }
+
+ int ok = 0;
+ STACK_OF(TRUST_TOKEN) *ret = sk_TRUST_TOKEN_new_null();
+ EC_RAW_POINT *BTs = OPENSSL_malloc(count * sizeof(EC_RAW_POINT));
+ EC_RAW_POINT *Zs = OPENSSL_malloc(count * sizeof(EC_RAW_POINT));
+ EC_SCALAR *dis = OPENSSL_malloc(count * sizeof(EC_SCALAR));
+ if (ret == NULL || !BTs || !Zs || !dis) {
+ goto err;
+ }
+
+ uint8_t seed[SHA384_DIGEST_LENGTH];
+ if (!compute_composite_seed(method, seed, &key->pubs)) {
+ goto err;
+ }
+
+ for (size_t i = 0; i < count; i++) {
+ const TRUST_TOKEN_PRETOKEN *pretoken =
+ sk_TRUST_TOKEN_PRETOKEN_value(pretokens, i);
+
+ EC_AFFINE Z_affine;
+ if (!cbs_get_point(cbs, group, &Z_affine)) {
+ OPENSSL_PUT_ERROR(TRUST_TOKEN, TRUST_TOKEN_R_DECODE_FAILURE);
+ goto err;
+ }
+
+ ec_affine_to_jacobian(group, &BTs[i], &pretoken->Tp);
+ ec_affine_to_jacobian(group, &Zs[i], &Z_affine);
+ if (!compute_composite_element(method, seed, &dis[i], i, &pretoken->Tp,
+ &Z_affine)) {
+ goto err;
+ }
+
+ // Unblind the token.
+ // pretoken->r is rinv.
+ EC_RAW_POINT N;
+ EC_AFFINE N_affine;
+ if (!ec_point_mul_scalar(group, &N, &Zs[i], &pretoken->r) ||
+ !ec_jacobian_to_affine(group, &N_affine, &N)) {
+ goto err;
+ }
+
+ // Serialize the token. Include |key_id| to avoid an extra copy in the layer
+ // above.
+ CBB token_cbb;
+ size_t point_len = 1 + 2 * BN_num_bytes(&group->field);
+ if (!CBB_init(&token_cbb, 4 + TRUST_TOKEN_NONCE_SIZE + (2 + point_len)) ||
+ !CBB_add_u32(&token_cbb, key_id) ||
+ !CBB_add_bytes(&token_cbb, pretoken->salt, TRUST_TOKEN_NONCE_SIZE) ||
+ !cbb_add_point(&token_cbb, group, &N_affine) ||
+ !CBB_flush(&token_cbb)) {
+ CBB_cleanup(&token_cbb);
+ goto err;
+ }
+
+ TRUST_TOKEN *token =
+ TRUST_TOKEN_new(CBB_data(&token_cbb), CBB_len(&token_cbb));
+ CBB_cleanup(&token_cbb);
+ if (token == NULL ||
+ !sk_TRUST_TOKEN_push(ret, token)) {
+ TRUST_TOKEN_free(token);
+ goto err;
+ }
+ }
+
+ EC_RAW_POINT M, Z;
+ if (!ec_point_mul_scalar_public_batch(group, &M,
+ /*g_scalar=*/NULL, BTs, dis,
+ count) ||
+ !ec_point_mul_scalar_public_batch(group, &Z,
+ /*g_scalar=*/NULL, Zs, dis,
+ count)) {
+ goto err;
+ }
+
+ CBS proof;
+ if (!CBS_get_u16_length_prefixed(cbs, &proof) ||
+ !verify_proof(method, &proof, key, &M, &Z) ||
+ CBS_len(&proof) != 0) {
+ goto err;
+ }
+
+ ok = 1;
+
+err:
+ OPENSSL_free(BTs);
+ OPENSSL_free(Zs);
+ OPENSSL_free(dis);
+ if (!ok) {
+ sk_TRUST_TOKEN_pop_free(ret, TRUST_TOKEN_free);
+ ret = NULL;
+ }
+ return ret;
+}
+
static int voprf_read(const VOPRF_METHOD *method,
const TRUST_TOKEN_ISSUER_KEY *key,
uint8_t out_nonce[TRUST_TOKEN_NONCE_SIZE],
@@ -804,8 +1225,8 @@
if (!voprf_exp2_init_method() || private_metadata != 0) {
return 0;
}
- return voprf_sign(&voprf_exp2_method, key, cbb, cbs, num_requested,
- num_to_issue);
+ return voprf_sign_tt(&voprf_exp2_method, key, cbb, cbs, num_requested,
+ num_to_issue);
}
STACK_OF(TRUST_TOKEN) *voprf_exp2_unblind(
@@ -815,7 +1236,8 @@
if (!voprf_exp2_init_method()) {
return NULL;
}
- return voprf_unblind(&voprf_exp2_method, key, pretokens, cbs, count, key_id);
+ return voprf_unblind_tt(&voprf_exp2_method, key, pretokens, cbs, count,
+ key_id);
}
int voprf_exp2_read(const TRUST_TOKEN_ISSUER_KEY *key,
@@ -834,16 +1256,17 @@
static int voprf_pst1_hash_to_group(const EC_GROUP *group, EC_RAW_POINT *out,
const uint8_t t[TRUST_TOKEN_NONCE_SIZE]) {
- const uint8_t kHashTLabel[] = "TrustToken VOPRF PST V1 HashToGroup";
- return ec_hash_to_curve_p384_xmd_sha384_sswu(
- group, out, kHashTLabel, sizeof(kHashTLabel), t, TRUST_TOKEN_NONCE_SIZE);
+ const uint8_t kHashTLabel[] = "HashToGroup-OPRFV1-\x01-P384-SHA384";
+ return ec_hash_to_curve_p384_xmd_sha384_sswu(group, out, kHashTLabel,
+ sizeof(kHashTLabel) - 1, t,
+ TRUST_TOKEN_NONCE_SIZE);
}
static int voprf_pst1_hash_to_scalar(const EC_GROUP *group, EC_SCALAR *out,
uint8_t *buf, size_t len) {
- const uint8_t kHashCLabel[] = "TrustToken VOPRF PST V1 HashToScalar";
- return ec_hash_to_scalar_p384_xmd_sha384(
- group, out, kHashCLabel, sizeof(kHashCLabel), buf, len);
+ const uint8_t kHashCLabel[] = "HashToScalar-OPRFV1-\x01-P384-SHA384";
+ return ec_hash_to_scalar_p384_xmd_sha384(group, out, kHashCLabel,
+ sizeof(kHashCLabel) - 1, buf, len);
}
static int voprf_pst1_ok = 0;
@@ -921,6 +1344,19 @@
num_to_issue);
}
+
+int voprf_pst1_sign_with_proof_scalar_for_testing(
+ const TRUST_TOKEN_ISSUER_KEY *key, CBB *cbb, CBS *cbs, size_t num_requested,
+ size_t num_to_issue, uint8_t private_metadata,
+ const uint8_t *proof_scalar_buf, size_t proof_scalar_len) {
+ if (!voprf_pst1_init_method() || private_metadata != 0) {
+ return 0;
+ }
+ return voprf_sign_with_proof_scalar_for_testing(
+ &voprf_pst1_method, key, cbb, cbs, num_requested, num_to_issue,
+ proof_scalar_buf, proof_scalar_len);
+}
+
STACK_OF(TRUST_TOKEN) *voprf_pst1_unblind(
const TRUST_TOKEN_CLIENT_KEY *key,
const STACK_OF(TRUST_TOKEN_PRETOKEN) *pretokens, CBS *cbs, size_t count,
