Add hash-to-curve code for P384.
Change-Id: I34c3609641c23aed14f2324c6887250369ae8b5f
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/40944
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/crypto/ec_extra/hash_to_curve.c b/crypto/ec_extra/hash_to_curve.c
index 407fa5d..04f37ad 100644
--- a/crypto/ec_extra/hash_to_curve.c
+++ b/crypto/ec_extra/hash_to_curve.c
@@ -120,7 +120,7 @@
size_t bits = BN_num_bits(modulus);
size_t L = (bits + k + 7) / 8;
// We require 2^(8*L) < 2^(2*bits - 2) <= n^2 so to fit in bounds for
- // |felem_reduce| and |ec_scalar_refuce|. All defined hash-to-curve suites
+ // |felem_reduce| and |ec_scalar_reduce|. All defined hash-to-curve suites
// define |k| to be well under this bound. (|k| is usually around half of
// |p_bits|.)
if (L * 8 >= 2 * bits - 2 ||
@@ -318,6 +318,55 @@
return ec_felem_from_bytes(group, out, bytes, len);
}
+int ec_hash_to_curve_p384_xmd_sha512_sswu(const EC_GROUP *group,
+ EC_RAW_POINT *out, const uint8_t *dst,
+ size_t dst_len, const uint8_t *msg,
+ size_t msg_len) {
+ // See section 8.3 of draft-irtf-cfrg-hash-to-curve-06.
+ if (EC_GROUP_get_curve_name(group) != NID_secp384r1) {
+ OPENSSL_PUT_ERROR(EC, EC_R_GROUP_MISMATCH);
+ return 0;
+ }
+
+ // kSqrt1728 was computed as follows in python3:
+ //
+ // p = 2**384 - 2**128 - 2**96 + 2**32 - 1
+ // z3 = 12**3
+ // c2 = pow(z3, (p+1)//4, p)
+ // assert z3 == pow(c2, 2, p)
+ // ", ".join("0x%02x" % b for b in c2.to_bytes(384//8, 'big')
+
+ static const uint8_t kSqrt1728[] = {
+ 0x01, 0x98, 0x77, 0xcc, 0x10, 0x41, 0xb7, 0x55, 0x57, 0x43, 0xc0, 0xae,
+ 0x2e, 0x3a, 0x3e, 0x61, 0xfb, 0x2a, 0xaa, 0x2e, 0x0e, 0x87, 0xea, 0x55,
+ 0x7a, 0x56, 0x3d, 0x8b, 0x59, 0x8a, 0x09, 0x40, 0xd0, 0xa6, 0x97, 0xa9,
+ 0xe0, 0xb9, 0xe9, 0x2c, 0xfa, 0xa3, 0x14, 0xf5, 0x83, 0xc9, 0xd0, 0x66
+ };
+
+ // Z = -12, c2 = sqrt(1728)
+ EC_FELEM Z, c2;
+ if (!felem_from_u8(group, &Z, 12) ||
+ !ec_felem_from_bytes(group, &c2, kSqrt1728, sizeof(kSqrt1728))) {
+ return 0;
+ }
+ ec_felem_neg(group, &Z, &Z);
+
+ return hash_to_curve(group, EVP_sha512(), &Z, &c2, /*k=*/192, out, dst,
+ dst_len, msg, msg_len);
+}
+
+int ec_hash_to_scalar_p384_xmd_sha512(const EC_GROUP *group, EC_SCALAR *out,
+ const uint8_t *dst, size_t dst_len,
+ const uint8_t *msg, size_t msg_len) {
+ if (EC_GROUP_get_curve_name(group) != NID_secp384r1) {
+ OPENSSL_PUT_ERROR(EC, EC_R_GROUP_MISMATCH);
+ return 0;
+ }
+
+ return hash_to_scalar(group, EVP_sha512(), out, dst, dst_len, /*k=*/192, msg,
+ msg_len);
+}
+
static int hash_to_curve_p521_xmd_sswu(const EC_GROUP *group, EC_RAW_POINT *out,
const uint8_t *dst, size_t dst_len,
const EVP_MD *md, unsigned k,
diff --git a/crypto/ec_extra/internal.h b/crypto/ec_extra/internal.h
index b05e9ea..eea282c 100644
--- a/crypto/ec_extra/internal.h
+++ b/crypto/ec_extra/internal.h
@@ -27,14 +27,30 @@
// Hash-to-curve.
//
// The following functions implement primitives from
-// draft-irtf-cfrg-hash-to-curve-06. We currently only implement a P-521 suite,
-// but others can be added as needed.
+// draft-irtf-cfrg-hash-to-curve-06. We currently only implement the P-384 and
+// P-521 suites, but others can be added as needed. The |dst| parameter in each
+// function is the domain separation tag and must be unique for each protocol
+// and between the |hash_to_curve| and |hash_to_scalar| variants. See
+// section 3.1 of the spec for additional guidance on this parameter.
+
+// ec_hash_to_curve_p384_sha512_sswu hashes |msg| to a point on |group| and
+// writes the result to |out|, implementing the P384_XMD:SHA-512_SSWU_RO_ suite.
+// It returns one on success and zero on error.
+OPENSSL_EXPORT int ec_hash_to_curve_p384_xmd_sha512_sswu(
+ const EC_GROUP *group, EC_RAW_POINT *out, const uint8_t *dst,
+ size_t dst_len, const uint8_t *msg, size_t msg_len);
+
+// ec_hash_to_scalar_p384_xmd_sha512 hashes |msg| to a scalar on |group| and
+// writes the result to |out|, using the hash_to_field operation from the
+// P384_XMD:SHA-512_SSWU_RO_ suite, but generating a value modulo the group
+// order rather than a field element.
+OPENSSL_EXPORT int ec_hash_to_scalar_p384_xmd_sha512(
+ const EC_GROUP *group, EC_SCALAR *out, const uint8_t *dst, size_t dst_len,
+ const uint8_t *msg, size_t msg_len);
// ec_hash_to_curve_p521_sha512_sswu hashes |msg| to a point on |group| and
// writes the result to |out|, implementing the P521_XMD:SHA-512_SSWU_RO_ suite.
-// It returns one on success and zero on error. |dst| is the domain separation
-// tag and must be unique for each protocol. See section 3.1 of
-// draft-irtf-cfrg-hash-to-curve-06 for additional guidance on this parameter.
+// It returns one on success and zero on error.
OPENSSL_EXPORT int ec_hash_to_curve_p521_xmd_sha512_sswu(
const EC_GROUP *group, EC_RAW_POINT *out, const uint8_t *dst,
size_t dst_len, const uint8_t *msg, size_t msg_len);
@@ -51,14 +67,7 @@
// ec_hash_to_scalar_p521_xmd_sha512 hashes |msg| to a scalar on |group| and
// writes the result to |out|, using the hash_to_field operation from the
// P521_XMD:SHA-512_SSWU_RO_ suite, but generating a value modulo the group
-// order rather than a field element. |dst| is the domain separation
-// tag and must be unique for each protocol. See section 3.1 of
-// draft-irtf-cfrg-hash-to-curve-06 for additional guidance on this parameter.
-//
-// Note the requirement to use a different tag for each encoding used in a
-// protocol extends to this function. Protocols which use both this function and
-// |ec_hash_to_scalar_p521_xmd_sha512| must use distinct values of |dst| for
-// each use.
+// order rather than a field element.
OPENSSL_EXPORT int ec_hash_to_scalar_p521_xmd_sha512(
const EC_GROUP *group, EC_SCALAR *out, const uint8_t *dst, size_t dst_len,
const uint8_t *msg, size_t msg_len);
diff --git a/crypto/fipsmodule/ec/ec_test.cc b/crypto/fipsmodule/ec/ec_test.cc
index 8697555..e08da93 100644
--- a/crypto/fipsmodule/ec/ec_test.cc
+++ b/crypto/fipsmodule/ec/ec_test.cc
@@ -1135,9 +1135,45 @@
const char *y_hex;
};
static const HashToCurveTest kTests[] = {
- // See draft-irtf-cfrg-hash-to-curve-06, appendix G.3.1. Note these test
- // |ec_hash_to_curve_p521_xmd_sha512_sswu_ref_for_testing| due to a spec
- // issue. See
+ // See draft-irtf-cfrg-hash-to-curve-06, appendix G.2.1.
+ {&ec_hash_to_curve_p384_xmd_sha512_sswu, NID_secp384r1,
+ "P384_XMD:SHA-512_SSWU_RO_TESTGEN", "",
+ "619d4168877421106aecb16ec35d84b7fdfa215cdb446d82bac49f"
+ "6eab51a34b4d5314823f7639293cf6471c6c981a99",
+ "e5035c694665ca25b2c57542673af6b91288110b0b0689657cd031"
+ "96976d82dec104fd9f91296c85d1ed94bc9309840e"},
+ {&ec_hash_to_curve_p384_xmd_sha512_sswu, NID_secp384r1,
+ "P384_XMD:SHA-512_SSWU_RO_TESTGEN", "abc",
+ "d7c33555606b86c3ffaa1a645f806bac9d553a769f5a735d75a395"
+ "d58a70956b6d3bdbd6a6a8c83121678a036005208a",
+ "e1c55f372a905040576f61fbc07e9664359e76f3e7b5be8dfe7224"
+ "720f85753a823e94a3f886ced2ec5ce13b1248147a"},
+ {&ec_hash_to_curve_p384_xmd_sha512_sswu, NID_secp384r1,
+ "P384_XMD:SHA-512_SSWU_RO_TESTGEN", "abcdef0123456789",
+ "d1f4bdd7ef9ee1c2d57ccd2b3b80123ccf3eb64b2f0a3ad26b8cd1"
+ "a8a8e411aadb9922d0e66a89ef0e78dba1489e23ea",
+ "9f376abd97ab8838c604a05ad17be1dfe0d924ddf0184341ec8e5a"
+ "ef9efb0f6559ab3048b4e1e0e42ac19ccb6d1dd892"},
+ {&ec_hash_to_curve_p384_xmd_sha512_sswu, NID_secp384r1,
+ "P384_XMD:SHA-512_SSWU_RO_TESTGEN",
+ "a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+ "1b669293d6edfd55ca7f9725d72fc62b55a8829738404a1239f2ca"
+ "783ad8f8a3ebe2ce54a28fcb6e9eca85d1ce29a929",
+ "25556bc2c6382c261feb362519f1e5d616518810262c358fb80e45"
+ "803ebcd0ce830b594da7a0e9de9eb13ad2d9191d34"},
+
+ // See draft-irtf-cfrg-hash-to-curve-06, appendix G.3.1. Note these tests
+ // use |ec_hash_to_curve_p521_xmd_sha512_sswu_ref_for_testing| due to a
+ // spec issue. See
// https://github.com/cfrg/draft-irtf-cfrg-hash-to-curve/issues/237. We
// expose and test this function to check our consistency with the rest of
// the reference implementation.
@@ -1265,27 +1301,55 @@
static const uint8_t kMessage[] = {4, 5, 6, 7};
EXPECT_FALSE(ec_hash_to_curve_p521_xmd_sha512_sswu(
p224.get(), &p, kDST, sizeof(kDST), kMessage, sizeof(kMessage)));
+ EXPECT_FALSE(ec_hash_to_curve_p384_xmd_sha512_sswu(
+ p224.get(), &p, kDST, sizeof(kDST), kMessage, sizeof(kMessage)));
}
TEST(ECTest, HashToScalar) {
- bssl::UniquePtr<EC_GROUP> group(EC_GROUP_new_by_curve_name(NID_secp521r1));
- ASSERT_TRUE(group);
-
struct HashToScalarTest {
+ int (*hash_to_scalar)(const EC_GROUP *group, EC_SCALAR *out,
+ const uint8_t *dst, size_t dst_len,
+ const uint8_t *msg, size_t msg_len);
+ int curve_nid;
const char *dst;
const char *msg;
const char *result_hex;
};
static const HashToScalarTest kTests[] = {
- {"P521_XMD:SHA-512_SCALAR_TEST", "",
+ {&ec_hash_to_scalar_p384_xmd_sha512, NID_secp384r1,
+ "P384_XMD:SHA-512_SCALAR_TEST", "",
+ "55f24775dd8ec265d9d1bf2f25b83806daf119db8646b3d263b156"
+ "8dbae4ee54aeafc757e4aa197da85504ad124d8ac8"},
+ {&ec_hash_to_scalar_p384_xmd_sha512, NID_secp384r1,
+ "P384_XMD:SHA-512_SCALAR_TEST", "abcdef0123456789",
+ "3af11c58bf0a3ee3560207c6bed9b5ecca5dc330426a6e1a601d36"
+ "c15d3818aeb48afb182036750bc5b46e6c20e8e2ff"},
+ {&ec_hash_to_scalar_p384_xmd_sha512, NID_secp384r1,
+ "P384_XMD:SHA-512_SCALAR_TEST",
+ "a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+ "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+ "2d5f927d15283f89d9d4932f93b77ab837e90bdf26b5f8beb2c794"
+ "bbd83032b6f1a445ef9f343a2b9311657e86e6ad43"},
+ {&ec_hash_to_scalar_p521_xmd_sha512, NID_secp521r1,
+ "P521_XMD:SHA-512_SCALAR_TEST", "",
"01a6206c2fc677c11d51807bf46d64a17f92396673074c5cee9299"
"4d28eec5445d5ed89799b30b39c964ecf62f39d59e7d43de15d910"
"c2c1d69f3ebc01eab241e5dc"},
- {"P521_XMD:SHA-512_SCALAR_TEST", "abcdef0123456789",
+ {&ec_hash_to_scalar_p521_xmd_sha512, NID_secp521r1,
+ "P521_XMD:SHA-512_SCALAR_TEST", "abcdef0123456789",
"00af484a5d9389a9912f555234c578d4b1b7c4a6f5009018d133a4"
"069172c9f5ce2d853b8643fe7bb50a83427ed3520a7a793c41a455"
"a02aa99431434fb6b5b0b26e"},
- {"P521_XMD:SHA-512_SCALAR_TEST",
+ {&ec_hash_to_scalar_p521_xmd_sha512, NID_secp521r1,
+ "P521_XMD:SHA-512_SCALAR_TEST",
"a512_aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
@@ -1305,8 +1369,10 @@
SCOPED_TRACE(test.dst);
SCOPED_TRACE(test.msg);
+ bssl::UniquePtr<EC_GROUP> group(EC_GROUP_new_by_curve_name(test.curve_nid));
+ ASSERT_TRUE(group);
EC_SCALAR scalar;
- ASSERT_TRUE(ec_hash_to_scalar_p521_xmd_sha512(
+ ASSERT_TRUE(test.hash_to_scalar(
group.get(), &scalar, reinterpret_cast<const uint8_t *>(test.dst),
strlen(test.dst), reinterpret_cast<const uint8_t *>(test.msg),
strlen(test.msg)));
@@ -1324,4 +1390,6 @@
static const uint8_t kMessage[] = {4, 5, 6, 7};
EXPECT_FALSE(ec_hash_to_scalar_p521_xmd_sha512(
p224.get(), &scalar, kDST, sizeof(kDST), kMessage, sizeof(kMessage)));
+ EXPECT_FALSE(ec_hash_to_scalar_p384_xmd_sha512(
+ p224.get(), &scalar, kDST, sizeof(kDST), kMessage, sizeof(kMessage)));
}
diff --git a/tool/speed.cc b/tool/speed.cc
index 8a05a3b..f403fe8 100644
--- a/tool/speed.cc
+++ b/tool/speed.cc
@@ -949,35 +949,63 @@
return true;
}
- EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp521r1);
- if (group == NULL) {
- return false;
- }
uint8_t input[64];
RAND_bytes(input, sizeof(input));
static const uint8_t kLabel[] = "label";
TimeResults results;
- if (!TimeFunction(&results, [&]() -> bool {
- EC_RAW_POINT out;
- return ec_hash_to_curve_p521_xmd_sha512_sswu(
- group, &out, kLabel, sizeof(kLabel), input, sizeof(input));
- })) {
- fprintf(stderr, "hash-to-curve failed.\n");
- return false;
- }
- results.Print("hash-to-curve P521_XMD:SHA-512_SSWU_RO_");
+ {
+ EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp521r1);
+ if (group == NULL) {
+ return false;
+ }
+ if (!TimeFunction(&results, [&]() -> bool {
+ EC_RAW_POINT out;
+ return ec_hash_to_curve_p521_xmd_sha512_sswu(
+ group, &out, kLabel, sizeof(kLabel), input, sizeof(input));
+ })) {
+ fprintf(stderr, "hash-to-curve failed.\n");
+ return false;
+ }
+ results.Print("hash-to-curve P521_XMD:SHA-512_SSWU_RO_");
- if (!TimeFunction(&results, [&]() -> bool {
- EC_SCALAR out;
- return ec_hash_to_scalar_p521_xmd_sha512(
- group, &out, kLabel, sizeof(kLabel), input, sizeof(input));
- })) {
- fprintf(stderr, "hash-to-scalar failed.\n");
- return false;
+ if (!TimeFunction(&results, [&]() -> bool {
+ EC_SCALAR out;
+ return ec_hash_to_scalar_p521_xmd_sha512(
+ group, &out, kLabel, sizeof(kLabel), input, sizeof(input));
+ })) {
+ fprintf(stderr, "hash-to-scalar failed.\n");
+ return false;
+ }
+ results.Print("hash-to-scalar P521_XMD:SHA-512");
}
- results.Print("hash-to-scalar P521_XMD:SHA-512");
+
+ {
+ EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp384r1);
+ if (group == NULL) {
+ return false;
+ }
+ if (!TimeFunction(&results, [&]() -> bool {
+ EC_RAW_POINT out;
+ return ec_hash_to_curve_p384_xmd_sha512_sswu(
+ group, &out, kLabel, sizeof(kLabel), input, sizeof(input));
+ })) {
+ fprintf(stderr, "hash-to-curve failed.\n");
+ return false;
+ }
+ results.Print("hash-to-curve P384_XMD:SHA-512_SSWU_RO_");
+
+ if (!TimeFunction(&results, [&]() -> bool {
+ EC_SCALAR out;
+ return ec_hash_to_scalar_p384_xmd_sha512(
+ group, &out, kLabel, sizeof(kLabel), input, sizeof(input));
+ })) {
+ fprintf(stderr, "hash-to-scalar failed.\n");
+ return false;
+ }
+ results.Print("hash-to-scalar P384_XMD:SHA-512");
+ }
return true;
}
