Add ECDH_compute_key_fips inside the module. This change adds a function so that an ECDH and the hashing of the resulting 'x' coordinate can occur inside the FIPS boundary. Change-Id: If93c20a70dc9dcbca49056f10915d3ce064f641f Reviewed-on: https://boringssl-review.googlesource.com/30104 Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/CMakeLists.txt b/crypto/CMakeLists.txt index 3d59354..526fec8 100644 --- a/crypto/CMakeLists.txt +++ b/crypto/CMakeLists.txt
@@ -109,7 +109,7 @@ add_subdirectory(dsa) add_subdirectory(rsa_extra) add_subdirectory(ec_extra) -add_subdirectory(ecdh) +add_subdirectory(ecdh_extra) add_subdirectory(ecdsa_extra) # Level 3 @@ -192,7 +192,7 @@ $<TARGET_OBJECTS:dsa> $<TARGET_OBJECTS:rsa_extra> $<TARGET_OBJECTS:ec_extra> - $<TARGET_OBJECTS:ecdh> + $<TARGET_OBJECTS:ecdh_extra> $<TARGET_OBJECTS:ecdsa_extra> $<TARGET_OBJECTS:cmac> $<TARGET_OBJECTS:evp> @@ -234,7 +234,7 @@ curve25519/ed25519_test.cc curve25519/spake25519_test.cc curve25519/x25519_test.cc - ecdh/ecdh_test.cc + ecdh_extra/ecdh_test.cc dh/dh_test.cc digest_extra/digest_test.cc dsa/dsa_test.cc
diff --git a/crypto/ecdh/CMakeLists.txt b/crypto/ecdh_extra/CMakeLists.txt similarity index 68% rename from crypto/ecdh/CMakeLists.txt rename to crypto/ecdh_extra/CMakeLists.txt index 8eaeae5..40a53c1 100644 --- a/crypto/ecdh/CMakeLists.txt +++ b/crypto/ecdh_extra/CMakeLists.txt
@@ -1,9 +1,9 @@ include_directories(../../include) add_library( - ecdh + ecdh_extra OBJECT - ecdh.c + ecdh_extra.c )
diff --git a/crypto/ecdh/ecdh.c b/crypto/ecdh_extra/ecdh_extra.c similarity index 100% rename from crypto/ecdh/ecdh.c rename to crypto/ecdh_extra/ecdh_extra.c
diff --git a/crypto/ecdh/ecdh_test.cc b/crypto/ecdh_extra/ecdh_test.cc similarity index 95% rename from crypto/ecdh/ecdh_test.cc rename to crypto/ecdh_extra/ecdh_test.cc index 1fbbd4b..bd4586f 100644 --- a/crypto/ecdh/ecdh_test.cc +++ b/crypto/ecdh_extra/ecdh_test.cc
@@ -28,6 +28,7 @@ #include <openssl/err.h> #include <openssl/evp.h> #include <openssl/nid.h> +#include <openssl/sha.h> #include "../test/file_test.h" #include "../test/test_util.h" @@ -68,7 +69,7 @@ } TEST(ECDHTest, TestVectors) { - FileTestGTest("crypto/ecdh/ecdh_tests.txt", [](FileTest *t) { + FileTestGTest("crypto/ecdh_extra/ecdh_tests.txt", [](FileTest *t) { bssl::UniquePtr<EC_GROUP> group = GetCurve(t, "Curve"); ASSERT_TRUE(group); bssl::UniquePtr<BIGNUM> priv_key = GetBIGNUM(t, "Private"); @@ -115,6 +116,13 @@ ASSERT_GE(ret, 0); EXPECT_EQ(Bytes(z.data(), z.size() - 1), Bytes(actual_z.data(), static_cast<size_t>(ret))); + + // Test that |ECDH_compute_key_fips| hashes as expected. + uint8_t digest[SHA256_DIGEST_LENGTH], expected_digest[SHA256_DIGEST_LENGTH]; + ASSERT_TRUE(ECDH_compute_key_fips(digest, sizeof(digest), + peer_pub_key.get(), key.get())); + SHA256(z.data(), z.size(), expected_digest); + EXPECT_EQ(Bytes(digest), Bytes(expected_digest)); }); }
diff --git a/crypto/ecdh/ecdh_tests.txt b/crypto/ecdh_extra/ecdh_tests.txt similarity index 100% rename from crypto/ecdh/ecdh_tests.txt rename to crypto/ecdh_extra/ecdh_tests.txt
diff --git a/crypto/err/ecdh.errordata b/crypto/err/ecdh.errordata index f714c30..d268509 100644 --- a/crypto/err/ecdh.errordata +++ b/crypto/err/ecdh.errordata
@@ -1,3 +1,4 @@ ECDH,100,KDF_FAILED ECDH,101,NO_PRIVATE_VALUE ECDH,102,POINT_ARITHMETIC_FAILURE +ECDH,103,UNKNOWN_DIGEST_LENGTH
diff --git a/crypto/fipsmodule/bcm.c b/crypto/fipsmodule/bcm.c index e456d3a..6b21f06 100644 --- a/crypto/fipsmodule/bcm.c +++ b/crypto/fipsmodule/bcm.c
@@ -57,6 +57,7 @@ #include "des/des.c" #include "digest/digest.c" #include "digest/digests.c" +#include "ecdh/ecdh.c" #include "ecdsa/ecdsa.c" #include "ec/ec.c" #include "ec/ec_key.c"
diff --git a/crypto/fipsmodule/ecdh/ecdh.c b/crypto/fipsmodule/ecdh/ecdh.c new file mode 100644 index 0000000..cd9d7ea --- /dev/null +++ b/crypto/fipsmodule/ecdh/ecdh.c
@@ -0,0 +1,161 @@ +/* ==================================================================== + * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. + * + * The Elliptic Curve Public-Key Crypto Library (ECC Code) included + * herein is developed by SUN MICROSYSTEMS, INC., and is contributed + * to the OpenSSL project. + * + * The ECC Code is licensed pursuant to the OpenSSL open source + * license provided below. + * + * The ECDH software is originally written by Douglas Stebila of + * Sun Microsystems Laboratories. + * + */ +/* ==================================================================== + * Copyright (c) 2000-2002 The OpenSSL Project. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. All advertising materials mentioning features or use of this + * software must display the following acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * licensing@OpenSSL.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + * + * This product includes cryptographic software written by Eric Young + * (eay@cryptsoft.com). This product includes software written by Tim + * Hudson (tjh@cryptsoft.com). */ + +#include <openssl/ecdh.h> + +#include <limits.h> +#include <string.h> + +#include <openssl/bn.h> +#include <openssl/ec.h> +#include <openssl/ec_key.h> +#include <openssl/err.h> +#include <openssl/mem.h> +#include <openssl/sha.h> + +#include "../ec/internal.h" + + +int ECDH_compute_key_fips(uint8_t *out, size_t out_len, const EC_POINT *pub_key, + const EC_KEY *priv_key) { + if (priv_key->priv_key == NULL) { + OPENSSL_PUT_ERROR(ECDH, ECDH_R_NO_PRIVATE_VALUE); + return 0; + } + const EC_SCALAR *const priv = &priv_key->priv_key->scalar; + + BN_CTX *ctx = BN_CTX_new(); + if (ctx == NULL) { + return 0; + } + BN_CTX_start(ctx); + + int ret = 0; + size_t buflen = 0; + uint8_t *buf = NULL; + + const EC_GROUP *const group = EC_KEY_get0_group(priv_key); + EC_POINT *shared_point = EC_POINT_new(group); + if (shared_point == NULL) { + OPENSSL_PUT_ERROR(ECDH, ERR_R_MALLOC_FAILURE); + goto err; + } + + if (!ec_point_mul_scalar(group, shared_point, NULL, pub_key, priv, ctx)) { + OPENSSL_PUT_ERROR(ECDH, ECDH_R_POINT_ARITHMETIC_FAILURE); + goto err; + } + + BIGNUM *x = BN_CTX_get(ctx); + if (!x) { + OPENSSL_PUT_ERROR(ECDH, ERR_R_MALLOC_FAILURE); + goto err; + } + + if (!EC_POINT_get_affine_coordinates_GFp(group, shared_point, x, NULL, ctx)) { + OPENSSL_PUT_ERROR(ECDH, ECDH_R_POINT_ARITHMETIC_FAILURE); + goto err; + } + + buflen = (EC_GROUP_get_degree(group) + 7) / 8; + buf = OPENSSL_malloc(buflen); + if (buf == NULL) { + OPENSSL_PUT_ERROR(ECDH, ERR_R_MALLOC_FAILURE); + goto err; + } + + if (!BN_bn2bin_padded(buf, buflen, x)) { + OPENSSL_PUT_ERROR(ECDH, ERR_R_INTERNAL_ERROR); + goto err; + } + + switch (out_len) { + case SHA224_DIGEST_LENGTH: + SHA224(buf, buflen, out); + break; + case SHA256_DIGEST_LENGTH: + SHA256(buf, buflen, out); + break; + case SHA384_DIGEST_LENGTH: + SHA384(buf, buflen, out); + break; + case SHA512_DIGEST_LENGTH: + SHA512(buf, buflen, out); + break; + default: + OPENSSL_PUT_ERROR(ECDH, ECDH_R_UNKNOWN_DIGEST_LENGTH); + goto err; + } + + ret = 1; + +err: + OPENSSL_free(buf); + EC_POINT_free(shared_point); + BN_CTX_end(ctx); + BN_CTX_free(ctx); + return ret; +}
diff --git a/fipstools/cavp_kas_test.cc b/fipstools/cavp_kas_test.cc index a304a48..f89bc97 100644 --- a/fipstools/cavp_kas_test.cc +++ b/fipstools/cavp_kas_test.cc
@@ -25,6 +25,7 @@ #include <openssl/ec_key.h> #include <openssl/err.h> #include <openssl/nid.h> +#include <openssl/sha.h> #include "../crypto/internal.h" #include "../crypto/test/file_test.h" @@ -35,20 +36,20 @@ const bool validate = *reinterpret_cast<bool *>(arg); int nid = NID_undef; - const EVP_MD *md = nullptr; + size_t digest_len = 0; if (t->HasInstruction("EB - SHA224")) { nid = NID_secp224r1; - md = EVP_sha224(); + digest_len = SHA224_DIGEST_LENGTH; } else if (t->HasInstruction("EC - SHA256")) { nid = NID_X9_62_prime256v1; - md = EVP_sha256(); + digest_len = SHA256_DIGEST_LENGTH; } else if (t->HasInstruction("ED - SHA384")) { nid = NID_secp384r1; - md = EVP_sha384(); + digest_len = SHA384_DIGEST_LENGTH; } else if (t->HasInstruction("EE - SHA512")) { nid = NID_secp521r1; - md = EVP_sha512(); + digest_len = SHA512_DIGEST_LENGTH; } else { return false; } @@ -86,17 +87,9 @@ return false; } - constexpr size_t kMaxCurveFieldBits = 521; - uint8_t shared_bytes[(kMaxCurveFieldBits + 7)/8]; - const int shared_bytes_len = - ECDH_compute_key(shared_bytes, sizeof(shared_bytes), their_point.get(), - ec_key.get(), nullptr); - uint8_t digest[EVP_MAX_MD_SIZE]; - unsigned digest_len; - if (shared_bytes_len < 0 || - !EVP_Digest(shared_bytes, shared_bytes_len, digest, &digest_len, md, - nullptr)) { + if (!ECDH_compute_key_fips(digest, digest_len, their_point.get(), + ec_key.get())) { return false; }
diff --git a/include/openssl/ecdh.h b/include/openssl/ecdh.h index 73e2140..0130ccc 100644 --- a/include/openssl/ecdh.h +++ b/include/openssl/ecdh.h
@@ -89,6 +89,22 @@ void *out, size_t outlen, const EC_POINT *pub_key, const EC_KEY *priv_key, void *(*kdf)(const void *in, size_t inlen, void *out, size_t *outlen)); +// ECDH_compute_key_fips calculates the shared key between |pub_key| and +// |priv_key| and hashes it with the appropriate SHA function for |out_len|. The +// only value values for |out_len| are thus 24 (SHA-224), 32 (SHA-256), 48 +// (SHA-384), and 64 (SHA-512). It returns one on success and zero on error. +// +// Note that the return value is different to |ECDH_compute_key|: it returns an +// error flag (as is common for BoringSSL) rather than the number of bytes +// written. +// +// This function allows the FIPS module to compute an ECDH and KDF within the +// module boundary without taking an arbitrary function pointer for the KDF, +// which isn't very FIPSy. +OPENSSL_EXPORT int ECDH_compute_key_fips(uint8_t *out, size_t out_len, + const EC_POINT *pub_key, + const EC_KEY *priv_key); + #if defined(__cplusplus) } // extern C @@ -97,5 +113,6 @@ #define ECDH_R_KDF_FAILED 100 #define ECDH_R_NO_PRIVATE_VALUE 101 #define ECDH_R_POINT_ARITHMETIC_FAILURE 102 +#define ECDH_R_UNKNOWN_DIGEST_LENGTH 103 #endif // OPENSSL_HEADER_ECDH_H
diff --git a/sources.cmake b/sources.cmake index 27fc1c4..f0c953b 100644 --- a/sources.cmake +++ b/sources.cmake
@@ -40,7 +40,7 @@ crypto/cmac/cavp_aes128_cmac_tests.txt crypto/cmac/cavp_aes192_cmac_tests.txt crypto/cmac/cavp_aes256_cmac_tests.txt - crypto/ecdh/ecdh_tests.txt + crypto/ecdh_extra/ecdh_tests.txt crypto/evp/evp_tests.txt crypto/evp/scrypt_tests.txt crypto/fipsmodule/aes/aes_tests.txt