diff --git a/cipher/ecc-curves.c b/cipher/ecc-curves.c index 9677d016..d6e541f0 100644 --- a/cipher/ecc-curves.c +++ b/cipher/ecc-curves.c @@ -1,1501 +1,1504 @@ /* ecc-curves.c - Elliptic Curve parameter mangement * Copyright (C) 2007, 2008, 2010, 2011 Free Software Foundation, Inc. * Copyright (C) 2013 g10 Code GmbH * * This file is part of Libgcrypt. * * Libgcrypt is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * Libgcrypt is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program; if not, see . */ #include #include #include #include #include #include "g10lib.h" #include "mpi.h" #include "mpi-internal.h" #include "cipher.h" #include "context.h" #include "ec-context.h" #include "pubkey-internal.h" #include "ecc-common.h" /* This tables defines aliases for curve names. */ static const struct { const char *name; /* Our name. */ const char *other; /* Other name. */ } curve_aliases[] = { { "Ed25519", "1.3.6.1.4.1.11591.15.1" }, /* OpenPGP */ { "Ed25519", "1.3.101.112" }, /* rfc8410 */ { "Curve25519", "1.3.6.1.4.1.3029.1.5.1" }, /* OpenPGP */ { "Curve25519", "1.3.101.110" }, /* rfc8410 */ { "Curve25519", "X25519" }, /* rfc8410 */ /* { "Ed448", "1.3.101.113" }, /\* rfc8410 *\/ */ { "X448", "1.3.101.111" }, /* rfc8410 */ { "NIST P-192", "1.2.840.10045.3.1.1" }, /* X9.62 OID */ { "NIST P-192", "prime192v1" }, /* X9.62 name. */ { "NIST P-192", "secp192r1" }, /* SECP name. */ { "NIST P-192", "nistp192" }, /* rfc5656. */ { "NIST P-224", "secp224r1" }, { "NIST P-224", "1.3.132.0.33" }, /* SECP OID. */ { "NIST P-224", "nistp224" }, /* rfc5656. */ { "NIST P-256", "1.2.840.10045.3.1.7" }, /* From NIST SP 800-78-1. */ { "NIST P-256", "prime256v1" }, { "NIST P-256", "secp256r1" }, { "NIST P-256", "nistp256" }, /* rfc5656. */ { "NIST P-384", "secp384r1" }, { "NIST P-384", "1.3.132.0.34" }, { "NIST P-384", "nistp384" }, /* rfc5656. */ { "NIST P-521", "secp521r1" }, { "NIST P-521", "1.3.132.0.35" }, { "NIST P-521", "nistp521" }, /* rfc5656. */ { "brainpoolP160r1", "1.3.36.3.3.2.8.1.1.1" }, { "brainpoolP192r1", "1.3.36.3.3.2.8.1.1.3" }, { "brainpoolP224r1", "1.3.36.3.3.2.8.1.1.5" }, { "brainpoolP256r1", "1.3.36.3.3.2.8.1.1.7" }, { "brainpoolP320r1", "1.3.36.3.3.2.8.1.1.9" }, { "brainpoolP384r1", "1.3.36.3.3.2.8.1.1.11"}, { "brainpoolP512r1", "1.3.36.3.3.2.8.1.1.13"}, { "GOST2001-test", "1.2.643.2.2.35.0" }, { "GOST2001-CryptoPro-A", "1.2.643.2.2.35.1" }, { "GOST2001-CryptoPro-B", "1.2.643.2.2.35.2" }, { "GOST2001-CryptoPro-C", "1.2.643.2.2.35.3" }, { "GOST2001-CryptoPro-A", "GOST2001-CryptoPro-XchA" }, { "GOST2001-CryptoPro-C", "GOST2001-CryptoPro-XchB" }, { "GOST2001-CryptoPro-A", "1.2.643.2.2.36.0" }, { "GOST2001-CryptoPro-C", "1.2.643.2.2.36.1" }, { "GOST2012-256-tc26-A", "1.2.643.7.1.2.1.1.1" }, { "GOST2001-CryptoPro-A", "1.2.643.7.1.2.1.1.2" }, { "GOST2001-CryptoPro-A", "GOST2012-256-tc26-B" }, { "GOST2001-CryptoPro-B", "1.2.643.7.1.2.1.1.3" }, { "GOST2001-CryptoPro-B", "GOST2012-256-tc26-C" }, { "GOST2001-CryptoPro-C", "1.2.643.7.1.2.1.1.4" }, { "GOST2001-CryptoPro-C", "GOST2012-256-tc26-D" }, { "GOST2012-512-test", "GOST2012-test" }, { "GOST2012-512-test", "1.2.643.7.1.2.1.2.0" }, { "GOST2012-512-tc26-A", "GOST2012-tc26-A" }, { "GOST2012-512-tc26-B", "GOST2012-tc26-B" }, { "GOST2012-512-tc26-A", "1.2.643.7.1.2.1.2.1" }, { "GOST2012-512-tc26-B", "1.2.643.7.1.2.1.2.2" }, { "GOST2012-512-tc26-C", "1.2.643.7.1.2.1.2.3" }, { "secp256k1", "1.3.132.0.10" }, { "sm2p256v1", "1.2.156.10197.1.301" }, { NULL, NULL} }; typedef struct { const char *desc; /* Description of the curve. */ unsigned int nbits; /* Number of bits. */ unsigned int fips:1; /* True if this is a FIPS140-2 approved curve. */ /* The model describing this curve. This is mainly used to select the group equation. */ enum gcry_mpi_ec_models model; /* The actual ECC dialect used. This is used for curve specific optimizations and to select encodings etc. */ enum ecc_dialects dialect; const char *p; /* The prime defining the field. */ const char *a, *b; /* The coefficients. For Twisted Edwards Curves b is used for d. For Montgomery Curves (a,b) has ((A-2)/4,B^-1). */ const char *n; /* The order of the base point. */ const char *g_x, *g_y; /* Base point. */ unsigned int h; /* Cofactor. */ } ecc_domain_parms_t; /* This static table defines all available curves. */ static const ecc_domain_parms_t domain_parms[] = { { /* (-x^2 + y^2 = 1 + dx^2y^2) */ "Ed25519", 255, 0, MPI_EC_EDWARDS, ECC_DIALECT_ED25519, "0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFED", "-0x01", "-0x2DFC9311D490018C7338BF8688861767FF8FF5B2BEBE27548A14B235ECA6874A", "0x1000000000000000000000000000000014DEF9DEA2F79CD65812631A5CF5D3ED", "0x216936D3CD6E53FEC0A4E231FDD6DC5C692CC7609525A7B2C9562D608F25D51A", "0x6666666666666666666666666666666666666666666666666666666666666658", 8 }, { /* (y^2 = x^3 + 486662*x^2 + x) */ "Curve25519", 255, 0, MPI_EC_MONTGOMERY, ECC_DIALECT_STANDARD, "0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFED", "0x01DB41", "0x01", "0x1000000000000000000000000000000014DEF9DEA2F79CD65812631A5CF5D3ED", "0x0000000000000000000000000000000000000000000000000000000000000009", "0x20AE19A1B8A086B4E01EDD2C7748D14C923D4D7E6D7C61B229E9C5A27ECED3D9", 8 /* Note: As per RFC-7748 errata eid4730 the g_y value should be * "0x5F51E65E475F794B1FE122D388B72EB36DC2B28192839E4DD6163A5D81312C14" * but that breaks the keygrip. The new value is recovered in * the function _gcry_ecc_fill_in_curve. See bug #4712. */ }, { /* (y^2 = x^3 + 156326*x^2 + x) */ "X448", 448, 0, MPI_EC_MONTGOMERY, ECC_DIALECT_SAFECURVE, "0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFE" "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF", "0x98A9", "0x01", "0x3FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF" "7CCA23E9C44EDB49AED63690216CC2728DC58F552378C292AB5844F3", "0x00000000000000000000000000000000000000000000000000000000" "00000000000000000000000000000000000000000000000000000005", "0x7D235D1295F5B1F66C98AB6E58326FCECBAE5D34F55545D060F75DC2" "8DF3F6EDB8027E2346430D211312C4B150677AF76FD7223D457B5B1A", 4, }, #if 0 /* No real specs yet found. */ { /* x^2 + y^2 = 1 + 3617x^2y^2 mod 2^414 - 17 */ "Curve3617", "0x3FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF" "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEF", MPI_EC_EDWARDS, 0, "0x01", "0x0e21", "0x07FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEB3CC92414CF" "706022B36F1C0338AD63CF181B0E71A5E106AF79", "0x1A334905141443300218C0631C326E5FCD46369F44C03EC7F57FF35498A4AB4D" "6D6BA111301A73FAA8537C64C4FD3812F3CBC595", "0x22", 8 }, #endif /*0*/ { "NIST P-192", 192, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xfffffffffffffffffffffffffffffffeffffffffffffffff", "0xfffffffffffffffffffffffffffffffefffffffffffffffc", "0x64210519e59c80e70fa7e9ab72243049feb8deecc146b9b1", "0xffffffffffffffffffffffff99def836146bc9b1b4d22831", "0x188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012", "0x07192b95ffc8da78631011ed6b24cdd573f977a11e794811", 1 }, { "NIST P-224", 224, 1, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xffffffffffffffffffffffffffffffff000000000000000000000001", "0xfffffffffffffffffffffffffffffffefffffffffffffffffffffffe", "0xb4050a850c04b3abf54132565044b0b7d7bfd8ba270b39432355ffb4", "0xffffffffffffffffffffffffffff16a2e0b8f03e13dd29455c5c2a3d" , "0xb70e0cbd6bb4bf7f321390b94a03c1d356c21122343280d6115c1d21", "0xbd376388b5f723fb4c22dfe6cd4375a05a07476444d5819985007e34", 1 }, { "NIST P-256", 256, 1, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff", "0xffffffff00000001000000000000000000000000fffffffffffffffffffffffc", "0x5ac635d8aa3a93e7b3ebbd55769886bc651d06b0cc53b0f63bce3c3e27d2604b", "0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551", "0x6b17d1f2e12c4247f8bce6e563a440f277037d812deb33a0f4a13945d898c296", "0x4fe342e2fe1a7f9b8ee7eb4a7c0f9e162bce33576b315ececbb6406837bf51f5", 1 }, { "NIST P-384", 384, 1, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe" "ffffffff0000000000000000ffffffff", "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe" "ffffffff0000000000000000fffffffc", "0xb3312fa7e23ee7e4988e056be3f82d19181d9c6efe8141120314088f5013875a" "c656398d8a2ed19d2a85c8edd3ec2aef", "0xffffffffffffffffffffffffffffffffffffffffffffffffc7634d81f4372ddf" "581a0db248b0a77aecec196accc52973", "0xaa87ca22be8b05378eb1c71ef320ad746e1d3b628ba79b9859f741e082542a38" "5502f25dbf55296c3a545e3872760ab7", "0x3617de4a96262c6f5d9e98bf9292dc29f8f41dbd289a147ce9da3113b5f0b8c0" "0a60b1ce1d7e819d7a431d7c90ea0e5f", 1 }, { "NIST P-521", 521, 1, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0x01ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0x01ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffc", "0x051953eb9618e1c9a1f929a21a0b68540eea2da725b99b315f3b8b489918ef10" "9e156193951ec7e937b1652c0bd3bb1bf073573df883d2c34f1ef451fd46b503f00", "0x01ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" "fffa51868783bf2f966b7fcc0148f709a5d03bb5c9b8899c47aebb6fb71e91386409", "0x00c6858e06b70404e9cd9e3ecb662395b4429c648139053fb521f828af606b4d" "3dbaa14b5e77efe75928fe1dc127a2ffa8de3348b3c1856a429bf97e7e31c2e5bd66", "0x011839296a789a3bc0045c8a5fb42c7d1bd998f54449579b446817afbd17273e" "662c97ee72995ef42640c550b9013fad0761353c7086a272c24088be94769fd16650", 1 }, { "brainpoolP160r1", 160, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xe95e4a5f737059dc60dfc7ad95b3d8139515620f", "0x340e7be2a280eb74e2be61bada745d97e8f7c300", "0x1e589a8595423412134faa2dbdec95c8d8675e58", "0xe95e4a5f737059dc60df5991d45029409e60fc09", "0xbed5af16ea3f6a4f62938c4631eb5af7bdbcdbc3", "0x1667cb477a1a8ec338f94741669c976316da6321", 1 }, { "brainpoolP192r1", 192, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xc302f41d932a36cda7a3463093d18db78fce476de1a86297", "0x6a91174076b1e0e19c39c031fe8685c1cae040e5c69a28ef", "0x469a28ef7c28cca3dc721d044f4496bcca7ef4146fbf25c9", "0xc302f41d932a36cda7a3462f9e9e916b5be8f1029ac4acc1", "0xc0a0647eaab6a48753b033c56cb0f0900a2f5c4853375fd6", "0x14b690866abd5bb88b5f4828c1490002e6773fa2fa299b8f", 1 }, { "brainpoolP224r1", 224, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xd7c134aa264366862a18302575d1d787b09f075797da89f57ec8c0ff", "0x68a5e62ca9ce6c1c299803a6c1530b514e182ad8b0042a59cad29f43", "0x2580f63ccfe44138870713b1a92369e33e2135d266dbb372386c400b", "0xd7c134aa264366862a18302575d0fb98d116bc4b6ddebca3a5a7939f", "0x0d9029ad2c7e5cf4340823b2a87dc68c9e4ce3174c1e6efdee12c07d", "0x58aa56f772c0726f24c6b89e4ecdac24354b9e99caa3f6d3761402cd", 1 }, { "brainpoolP256r1", 256, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xa9fb57dba1eea9bc3e660a909d838d726e3bf623d52620282013481d1f6e5377", "0x7d5a0975fc2c3057eef67530417affe7fb8055c126dc5c6ce94a4b44f330b5d9", "0x26dc5c6ce94a4b44f330b5d9bbd77cbf958416295cf7e1ce6bccdc18ff8c07b6", "0xa9fb57dba1eea9bc3e660a909d838d718c397aa3b561a6f7901e0e82974856a7", "0x8bd2aeb9cb7e57cb2c4b482ffc81b7afb9de27e1e3bd23c23a4453bd9ace3262", "0x547ef835c3dac4fd97f8461a14611dc9c27745132ded8e545c1d54c72f046997", 1 }, { "brainpoolP320r1", 320, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xd35e472036bc4fb7e13c785ed201e065f98fcfa6f6f40def4f92b9ec7893ec28" "fcd412b1f1b32e27", "0x3ee30b568fbab0f883ccebd46d3f3bb8a2a73513f5eb79da66190eb085ffa9f4" "92f375a97d860eb4", "0x520883949dfdbc42d3ad198640688a6fe13f41349554b49acc31dccd88453981" "6f5eb4ac8fb1f1a6", "0xd35e472036bc4fb7e13c785ed201e065f98fcfa5b68f12a32d482ec7ee8658e9" "8691555b44c59311", "0x43bd7e9afb53d8b85289bcc48ee5bfe6f20137d10a087eb6e7871e2a10a599c7" "10af8d0d39e20611", "0x14fdd05545ec1cc8ab4093247f77275e0743ffed117182eaa9c77877aaac6ac7" "d35245d1692e8ee1", 1 }, { "brainpoolP384r1", 384, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0x8cb91e82a3386d280f5d6f7e50e641df152f7109ed5456b412b1da197fb71123" "acd3a729901d1a71874700133107ec53", "0x7bc382c63d8c150c3c72080ace05afa0c2bea28e4fb22787139165efba91f90f" "8aa5814a503ad4eb04a8c7dd22ce2826", "0x04a8c7dd22ce28268b39b55416f0447c2fb77de107dcd2a62e880ea53eeb62d5" "7cb4390295dbc9943ab78696fa504c11", "0x8cb91e82a3386d280f5d6f7e50e641df152f7109ed5456b31f166e6cac0425a7" "cf3ab6af6b7fc3103b883202e9046565", "0x1d1c64f068cf45ffa2a63a81b7c13f6b8847a3e77ef14fe3db7fcafe0cbd10e8" "e826e03436d646aaef87b2e247d4af1e", "0x8abe1d7520f9c2a45cb1eb8e95cfd55262b70b29feec5864e19c054ff9912928" "0e4646217791811142820341263c5315", 1 }, { "brainpoolP512r1", 512, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xaadd9db8dbe9c48b3fd4e6ae33c9fc07cb308db3b3c9d20ed6639cca70330871" "7d4d9b009bc66842aecda12ae6a380e62881ff2f2d82c68528aa6056583a48f3", "0x7830a3318b603b89e2327145ac234cc594cbdd8d3df91610a83441caea9863bc" "2ded5d5aa8253aa10a2ef1c98b9ac8b57f1117a72bf2c7b9e7c1ac4d77fc94ca", "0x3df91610a83441caea9863bc2ded5d5aa8253aa10a2ef1c98b9ac8b57f1117a7" "2bf2c7b9e7c1ac4d77fc94cadc083e67984050b75ebae5dd2809bd638016f723", "0xaadd9db8dbe9c48b3fd4e6ae33c9fc07cb308db3b3c9d20ed6639cca70330870" "553e5c414ca92619418661197fac10471db1d381085ddaddb58796829ca90069", "0x81aee4bdd82ed9645a21322e9c4c6a9385ed9f70b5d916c1b43b62eef4d0098e" "ff3b1f78e2d0d48d50d1687b93b97d5f7c6d5047406a5e688b352209bcb9f822", "0x7dde385d566332ecc0eabfa9cf7822fdf209f70024a57b1aa000c55b881f8111" "b2dcde494a5f485e5bca4bd88a2763aed1ca2b2fa8f0540678cd1e0f3ad80892", 1 }, { "GOST2001-test", 256, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0x8000000000000000000000000000000000000000000000000000000000000431", "0x0000000000000000000000000000000000000000000000000000000000000007", "0x5fbff498aa938ce739b8e022fbafef40563f6e6a3472fc2a514c0ce9dae23b7e", "0x8000000000000000000000000000000150fe8a1892976154c59cfc193accf5b3", "0x0000000000000000000000000000000000000000000000000000000000000002", "0x08e2a8a0e65147d4bd6316030e16d19c85c97f0a9ca267122b96abbcea7e8fc8", 1 }, { "GOST2001-CryptoPro-A", 256, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffd97", "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffd94", "0x00000000000000000000000000000000000000000000000000000000000000a6", "0xffffffffffffffffffffffffffffffff6c611070995ad10045841b09b761b893", "0x0000000000000000000000000000000000000000000000000000000000000001", "0x8d91e471e0989cda27df505a453f2b7635294f2ddf23e3b122acc99c9e9f1e14", 1 }, { "GOST2001-CryptoPro-B", 256, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0x8000000000000000000000000000000000000000000000000000000000000c99", "0x8000000000000000000000000000000000000000000000000000000000000c96", "0x3e1af419a269a5f866a7d3c25c3df80ae979259373ff2b182f49d4ce7e1bbc8b", "0x800000000000000000000000000000015f700cfff1a624e5e497161bcc8a198f", "0x0000000000000000000000000000000000000000000000000000000000000001", "0x3fa8124359f96680b83d1c3eb2c070e5c545c9858d03ecfb744bf8d717717efc", 1 }, { "GOST2001-CryptoPro-C", 256, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0x9b9f605f5a858107ab1ec85e6b41c8aacf846e86789051d37998f7b9022d759b", "0x9b9f605f5a858107ab1ec85e6b41c8aacf846e86789051d37998f7b9022d7598", "0x000000000000000000000000000000000000000000000000000000000000805a", "0x9b9f605f5a858107ab1ec85e6b41c8aa582ca3511eddfb74f02f3a6598980bb9", "0x0000000000000000000000000000000000000000000000000000000000000000", "0x41ece55743711a8c3cbf3783cd08c0ee4d4dc440d4641a8f366e550dfdb3bb67", 1 }, { "GOST2012-256-A", 256, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffd97", "0xc2173f1513981673af4892c23035a27ce25e2013bf95aa33b22c656f277e7335", "0x295f9bae7428ed9ccc20e7c359a9d41a22fccd9108e17bf7ba9337a6f8ae9513", "0x400000000000000000000000000000000fd8cddfc87b6635c115af556c360c67", "0x91e38443a5e82c0d880923425712b2bb658b9196932e02c78b2582fe742daa28", "0x32879423ab1a0375895786c4bb46e9565fde0b5344766740af268adb32322e5c", 4 }, { "GOST2012-512-test", 511, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0x4531acd1fe0023c7550d267b6b2fee80922b14b2ffb90f04d4eb7c09b5d2d15d" "f1d852741af4704a0458047e80e4546d35b8336fac224dd81664bbf528be6373", "0x0000000000000000000000000000000000000000000000000000000000000007", "0x1cff0806a31116da29d8cfa54e57eb748bc5f377e49400fdd788b649eca1ac4" "361834013b2ad7322480a89ca58e0cf74bc9e540c2add6897fad0a3084f302adc", "0x4531acd1fe0023c7550d267b6b2fee80922b14b2ffb90f04d4eb7c09b5d2d15d" "a82f2d7ecb1dbac719905c5eecc423f1d86e25edbe23c595d644aaf187e6e6df", "0x24d19cc64572ee30f396bf6ebbfd7a6c5213b3b3d7057cc825f91093a68cd762" "fd60611262cd838dc6b60aa7eee804e28bc849977fac33b4b530f1b120248a9a", "0x2bb312a43bd2ce6e0d020613c857acddcfbf061e91e5f2c3f32447c259f39b2" "c83ab156d77f1496bf7eb3351e1ee4e43dc1a18b91b24640b6dbb92cb1add371e", 1 }, { "GOST2012-512-tc26-A", 512, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffdc7", "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffdc4", "0xe8c2505dedfc86ddc1bd0b2b6667f1da34b82574761cb0e879bd081cfd0b6265" "ee3cb090f30d27614cb4574010da90dd862ef9d4ebee4761503190785a71c760", "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" "27e69532f48d89116ff22b8d4e0560609b4b38abfad2b85dcacdb1411f10b275", "0x0000000000000000000000000000000000000000000000000000000000000000" "0000000000000000000000000000000000000000000000000000000000000003", "0x7503cfe87a836ae3a61b8816e25450e6ce5e1c93acf1abc1778064fdcbefa921" "df1626be4fd036e93d75e6a50e3a41e98028fe5fc235f5b889a589cb5215f2a4", 1 }, { "GOST2012-512-tc26-B", 512, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0x8000000000000000000000000000000000000000000000000000000000000000" "000000000000000000000000000000000000000000000000000000000000006f", "0x8000000000000000000000000000000000000000000000000000000000000000" "000000000000000000000000000000000000000000000000000000000000006c", "0x687d1b459dc841457e3e06cf6f5e2517b97c7d614af138bcbf85dc806c4b289f" "3e965d2db1416d217f8b276fad1ab69c50f78bee1fa3106efb8ccbc7c5140116", "0x8000000000000000000000000000000000000000000000000000000000000001" "49a1ec142565a545acfdb77bd9d40cfa8b996712101bea0ec6346c54374f25bd", "0x0000000000000000000000000000000000000000000000000000000000000000" "0000000000000000000000000000000000000000000000000000000000000002", "0x1a8f7eda389b094c2c071e3647a8940f3c123b697578c213be6dd9e6c8ec7335" "dcb228fd1edf4a39152cbcaaf8c0398828041055f94ceeec7e21340780fe41bd", 1 }, { "GOST2012-512-tc26-C", 512, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffdc7", "0xdc9203e514a721875485a529d2c722fb187bc8980eb866644de41c68e1430645" "46e861c0e2c9edd92ade71f46fcf50ff2ad97f951fda9f2a2eb6546f39689bd3", "0xb4c4ee28cebc6c2c8ac12952cf37f16ac7efb6a9f69f4b57ffda2e4f0de5ade0" "38cbc2fff719d2c18de0284b8bfef3b52b8cc7a5f5bf0a3c8d2319a5312557e1", "0x3fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" "c98cdba46506ab004c33a9ff5147502cc8eda9e7a769a12694623cef47f023ed", "0xe2e31edfc23de7bdebe241ce593ef5de2295b7a9cbaef021d385f7074cea043a" "a27272a7ae602bf2a7b9033db9ed3610c6fb85487eae97aac5bc7928c1950148", "0xf5ce40d95b5eb899abbccff5911cb8577939804d6527378b8c108c3d2090ff9be" "18e2d33e3021ed2ef32d85822423b6304f726aa854bae07d0396e9a9addc40f", 4 }, { "secp256k1", 256, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F", "0x0000000000000000000000000000000000000000000000000000000000000000", "0x0000000000000000000000000000000000000000000000000000000000000007", "0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141", "0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798", "0x483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8", 1 }, { "sm2p256v1", 256, 0, MPI_EC_WEIERSTRASS, ECC_DIALECT_STANDARD, "0xfffffffeffffffffffffffffffffffffffffffff00000000ffffffffffffffff", "0xfffffffeffffffffffffffffffffffffffffffff00000000fffffffffffffffc", "0x28e9fa9e9d9f5e344d5a9e4bcf6509a7f39789f515ab8f92ddbcbd414d940e93", "0xfffffffeffffffffffffffffffffffff7203df6b21c6052b53bbf40939d54123", "0x32c4ae2c1f1981195f9904466a39c9948fe30bbff2660be1715a4589334c74c7", "0xbc3736a2f4f6779c59bdcee36b692153d0a9877cc62a474002df32e52139f0a0", 1 }, { NULL, 0, 0, 0, 0, NULL, NULL, NULL, NULL, NULL } }; /* Return a copy of POINT. */ static gcry_mpi_point_t point_copy (gcry_mpi_point_t point) { gcry_mpi_point_t newpoint; if (point) { newpoint = mpi_point_new (0); point_set (newpoint, point); } else newpoint = NULL; return newpoint; } /* Helper to scan a hex string. */ static gcry_mpi_t scanval (const char *string) { gpg_err_code_t rc; gcry_mpi_t val; rc = _gcry_mpi_scan (&val, GCRYMPI_FMT_HEX, string, 0, NULL); if (rc) log_fatal ("scanning ECC parameter failed: %s\n", gpg_strerror (rc)); return val; } /* Return the index of the domain_parms table for a curve with NAME. Return -1 if not found. */ static int find_domain_parms_idx (const char *name) { int idx, aliasno; /* First check our native curves. */ for (idx = 0; domain_parms[idx].desc; idx++) if (!strcmp (name, domain_parms[idx].desc)) return idx; /* If not found consult the alias table. */ if (!domain_parms[idx].desc) { for (aliasno = 0; curve_aliases[aliasno].name; aliasno++) if (!strcmp (name, curve_aliases[aliasno].other)) break; if (curve_aliases[aliasno].name) { for (idx = 0; domain_parms[idx].desc; idx++) if (!strcmp (curve_aliases[aliasno].name, domain_parms[idx].desc)) return idx; } } return -1; } /* Generate the crypto system setup. This function takes the NAME of a curve or the desired number of bits and stores at R_CURVE the parameters of the named curve or those of a suitable curve. If R_NBITS is not NULL, the chosen number of bits is stored there. NULL may be given for R_CURVE, if the value is not required and for example only a quick test for availability is desired. Note that the curve fields should be initialized to zero because fields which are not NULL are skipped. */ gpg_err_code_t _gcry_ecc_fill_in_curve (unsigned int nbits, const char *name, elliptic_curve_t *curve, unsigned int *r_nbits) { int idx; const char *resname = NULL; /* Set to a found curve name. */ if (name) idx = find_domain_parms_idx (name); else { for (idx = 0; domain_parms[idx].desc; idx++) if (nbits == domain_parms[idx].nbits && domain_parms[idx].model == MPI_EC_WEIERSTRASS) break; if (!domain_parms[idx].desc) idx = -1; } if (idx < 0) return GPG_ERR_UNKNOWN_CURVE; resname = domain_parms[idx].desc; /* In fips mode we only support NIST curves. Note that it is possible to bypass this check by specifying the curve parameters directly. */ if (fips_mode () && !domain_parms[idx].fips ) return GPG_ERR_NOT_SUPPORTED; switch (domain_parms[idx].model) { case MPI_EC_WEIERSTRASS: case MPI_EC_EDWARDS: case MPI_EC_MONTGOMERY: break; default: return GPG_ERR_BUG; } if (r_nbits) *r_nbits = domain_parms[idx].nbits; if (curve) { curve->model = domain_parms[idx].model; curve->dialect = domain_parms[idx].dialect; if (!curve->p) curve->p = scanval (domain_parms[idx].p); if (!curve->a) { curve->a = scanval (domain_parms[idx].a); if (curve->a->sign) { mpi_resize (curve->a, curve->p->nlimbs); _gcry_mpih_sub_n (curve->a->d, curve->p->d, curve->a->d, curve->p->nlimbs); curve->a->nlimbs = curve->p->nlimbs; curve->a->sign = 0; } } if (!curve->b) { curve->b = scanval (domain_parms[idx].b); if (curve->b->sign) { mpi_resize (curve->b, curve->p->nlimbs); _gcry_mpih_sub_n (curve->b->d, curve->p->d, curve->b->d, curve->p->nlimbs); curve->b->nlimbs = curve->p->nlimbs; curve->b->sign = 0; } } if (!curve->n) curve->n = scanval (domain_parms[idx].n); if (!curve->G.x) curve->G.x = scanval (domain_parms[idx].g_x); if (!curve->G.y) curve->G.y = scanval (domain_parms[idx].g_y); curve->h = domain_parms[idx].h; /* * In the constants of domain_parms, we defined Curve25519 * domain parameters as the ones in RFC-7748 before the errata * (eid4730). To keep the computation having exact same values, * we recover the new value of g_y, here. */ if (!strcmp (resname, "Curve25519")) mpi_sub (curve->G.y, curve->p, curve->G.y); if (!curve->G.z) curve->G.z = mpi_alloc_set_ui (1); if (!curve->name) curve->name = resname; } return 0; } /* Give the name of the curve NAME, store the curve parameters into P, A, B, G, and N if they point to NULL value. Note that G is returned in standard uncompressed format. Also update MODEL and DIALECT if they are not NULL. */ gpg_err_code_t _gcry_ecc_update_curve_param (const char *name, enum gcry_mpi_ec_models *model, enum ecc_dialects *dialect, gcry_mpi_t *p, gcry_mpi_t *a, gcry_mpi_t *b, gcry_mpi_t *g, gcry_mpi_t *n) { int idx; idx = find_domain_parms_idx (name); if (idx < 0) return GPG_ERR_UNKNOWN_CURVE; if (g) { char *buf; size_t len; len = 4; len += strlen (domain_parms[idx].g_x+2); len += strlen (domain_parms[idx].g_y+2); len++; buf = xtrymalloc (len); if (!buf) return gpg_err_code_from_syserror (); strcpy (stpcpy (stpcpy (buf, "0x04"), domain_parms[idx].g_x+2), domain_parms[idx].g_y+2); _gcry_mpi_release (*g); *g = scanval (buf); xfree (buf); } if (model) *model = domain_parms[idx].model; if (dialect) *dialect = domain_parms[idx].dialect; if (p) { _gcry_mpi_release (*p); *p = scanval (domain_parms[idx].p); } if (a) { _gcry_mpi_release (*a); *a = scanval (domain_parms[idx].a); } if (b) { _gcry_mpi_release (*b); *b = scanval (domain_parms[idx].b); } if (n) { _gcry_mpi_release (*n); *n = scanval (domain_parms[idx].n); } return 0; } /* Return the name matching the parameters in PKEY. This works only with curves described by the Weierstrass equation. */ const char * _gcry_ecc_get_curve (gcry_sexp_t keyparms, int iterator, unsigned int *r_nbits) { gpg_err_code_t rc; const char *result = NULL; elliptic_curve_t E; gcry_mpi_t mpi_g = NULL; gcry_mpi_t tmp = NULL; int idx; memset (&E, 0, sizeof E); if (r_nbits) *r_nbits = 0; if (!keyparms) { idx = iterator; if (idx >= 0 && idx < DIM (domain_parms)) { result = domain_parms[idx].desc; if (r_nbits) *r_nbits = domain_parms[idx].nbits; } return result; } /* * Extract the curve parameters.. */ rc = gpg_err_code (sexp_extract_param (keyparms, NULL, "pabgn", &E.p, &E.a, &E.b, &mpi_g, &E.n, NULL)); if (rc == GPG_ERR_NO_OBJ) { /* This might be the second use case of checking whether a specific curve given by name is supported. */ gcry_sexp_t l1; char *name; l1 = sexp_find_token (keyparms, "curve", 5); if (!l1) goto leave; /* No curve name parameter. */ name = sexp_nth_string (l1, 1); sexp_release (l1); if (!name) goto leave; /* Name missing or out of core. */ idx = find_domain_parms_idx (name); xfree (name); if (idx >= 0) /* Curve found. */ { result = domain_parms[idx].desc; if (r_nbits) *r_nbits = domain_parms[idx].nbits; } return result; } if (rc) goto leave; if (mpi_g) { _gcry_mpi_point_init (&E.G); if (_gcry_ecc_os2ec (&E.G, mpi_g)) goto leave; } for (idx = 0; domain_parms[idx].desc; idx++) { mpi_free (tmp); tmp = scanval (domain_parms[idx].p); if (!mpi_cmp (tmp, E.p)) { mpi_free (tmp); tmp = scanval (domain_parms[idx].a); if (!mpi_cmp (tmp, E.a)) { mpi_free (tmp); tmp = scanval (domain_parms[idx].b); if (!mpi_cmp (tmp, E.b)) { mpi_free (tmp); tmp = scanval (domain_parms[idx].n); if (!mpi_cmp (tmp, E.n)) { mpi_free (tmp); tmp = scanval (domain_parms[idx].g_x); if (!mpi_cmp (tmp, E.G.x)) { mpi_free (tmp); tmp = scanval (domain_parms[idx].g_y); if (!mpi_cmp (tmp, E.G.y)) { result = domain_parms[idx].desc; if (r_nbits) *r_nbits = domain_parms[idx].nbits; goto leave; } } } } } } } leave: _gcry_mpi_release (tmp); _gcry_mpi_release (E.p); _gcry_mpi_release (E.a); _gcry_mpi_release (E.b); _gcry_mpi_release (mpi_g); _gcry_mpi_point_free_parts (&E.G); _gcry_mpi_release (E.n); return result; } /* Helper to extract an MPI from key parameters. */ static gpg_err_code_t mpi_from_keyparam (gcry_mpi_t *r_a, gcry_sexp_t keyparam, const char *name, int opaque) { gcry_err_code_t ec = 0; gcry_sexp_t l1; l1 = sexp_find_token (keyparam, name, 0); if (l1) { *r_a = sexp_nth_mpi (l1, 1, opaque? GCRYMPI_FMT_OPAQUE : GCRYMPI_FMT_USG); sexp_release (l1); if (!*r_a) ec = GPG_ERR_INV_OBJ; } return ec; } /* Helper to extract a point from key parameters. If no parameter with NAME is found, the functions tries to find a non-encoded point by appending ".x", ".y" and ".z" to NAME. ".z" is in this case optional and defaults to 1. EC is the context which at this point may not be fully initialized. */ static gpg_err_code_t point_from_keyparam (gcry_mpi_point_t *r_a, gcry_sexp_t keyparam, const char *name, mpi_ec_t ec) { gcry_err_code_t rc; gcry_sexp_t l1; gcry_mpi_point_t point; l1 = sexp_find_token (keyparam, name, 0); if (l1) { gcry_mpi_t a; a = sexp_nth_mpi (l1, 1, GCRYMPI_FMT_OPAQUE); sexp_release (l1); if (!a) return GPG_ERR_INV_OBJ; point = mpi_point_new (0); rc = _gcry_mpi_ec_decode_point (point, a, ec); mpi_free (a); if (rc) { mpi_point_release (point); return rc; } } else { char *tmpname; gcry_mpi_t x = NULL; gcry_mpi_t y = NULL; gcry_mpi_t z = NULL; tmpname = xtrymalloc (strlen (name) + 2 + 1); if (!tmpname) return gpg_err_code_from_syserror (); strcpy (stpcpy (tmpname, name), ".x"); rc = mpi_from_keyparam (&x, keyparam, tmpname, 0); if (rc) { xfree (tmpname); return rc; } strcpy (stpcpy (tmpname, name), ".y"); rc = mpi_from_keyparam (&y, keyparam, tmpname, 0); if (rc) { mpi_free (x); xfree (tmpname); return rc; } strcpy (stpcpy (tmpname, name), ".z"); rc = mpi_from_keyparam (&z, keyparam, tmpname, 0); if (rc) { mpi_free (y); mpi_free (x); xfree (tmpname); return rc; } if (!z) z = mpi_set_ui (NULL, 1); if (x && y) point = mpi_point_snatch_set (NULL, x, y, z); else { mpi_free (x); mpi_free (y); mpi_free (z); point = NULL; } xfree (tmpname); } if (point) *r_a = point; return 0; } static gpg_err_code_t mpi_ec_get_elliptic_curve (elliptic_curve_t *E, int *r_flags, gcry_sexp_t keyparam, const char *curvename) { gpg_err_code_t errc; unsigned int nbits; gcry_sexp_t l1; errc = _gcry_pk_util_get_nbits (keyparam, &nbits); if (errc) return errc; E->model = MPI_EC_WEIERSTRASS; E->dialect = ECC_DIALECT_STANDARD; E->h = 1; if (keyparam) { /* Parse an optional flags list. */ l1 = sexp_find_token (keyparam, "flags", 0); if (l1) { int flags = 0; errc = _gcry_pk_util_parse_flaglist (l1, &flags, NULL); sexp_release (l1); l1 = NULL; if (errc) goto leave; *r_flags |= flags; } /* Parse the deprecated optional transient-key flag. */ l1 = sexp_find_token (keyparam, "transient-key", 0); if (l1) { *r_flags |= PUBKEY_FLAG_TRANSIENT_KEY; sexp_release (l1); } /* Check whether a curve name was given. */ l1 = sexp_find_token (keyparam, "curve", 5); /* If we don't have a curve name or if override parameters have explicitly been requested, parse them. */ if (!l1 || (*r_flags & PUBKEY_FLAG_PARAM)) { gcry_mpi_point_t G = NULL; gcry_mpi_t cofactor = NULL; errc = mpi_from_keyparam (&E->p, keyparam, "p", 0); if (errc) goto leave; errc = mpi_from_keyparam (&E->a, keyparam, "a", 0); if (errc) goto leave; errc = mpi_from_keyparam (&E->b, keyparam, "b", 0); if (errc) goto leave; errc = point_from_keyparam (&G, keyparam, "g", NULL); if (errc) goto leave; if (G) { _gcry_mpi_point_init (&E->G); mpi_point_set (&E->G, G->x, G->y, G->z); mpi_point_set (G, NULL, NULL, NULL); mpi_point_release (G); } errc = mpi_from_keyparam (&E->n, keyparam, "n", 0); if (errc) goto leave; errc = mpi_from_keyparam (&cofactor, keyparam, "h", 0); if (errc) goto leave; if (cofactor) { mpi_get_ui (&E->h, cofactor); mpi_free (cofactor); } } } else l1 = NULL; /* No curvename. */ /* Check whether a curve parameter is available and use that to fill in missing values. If no curve parameter is available try an optional provided curvename. If only the curvename has been given use that one. */ if (l1 || curvename || nbits) { char *name; if (l1) { name = sexp_nth_string (l1, 1); sexp_release (l1); if (!name) { errc = GPG_ERR_INV_OBJ; /* Name missing or out of core. */ goto leave; } } else name = NULL; errc = _gcry_ecc_fill_in_curve (nbits, name? name : curvename, E, NULL); xfree (name); if (errc) goto leave; } leave: return errc; } static gpg_err_code_t mpi_ec_setup_elliptic_curve (mpi_ec_t ec, int flags, elliptic_curve_t *E, gcry_sexp_t keyparam) { gpg_err_code_t errc = 0; ec->G = mpi_point_snatch_set (NULL, E->G.x, E->G.y, E->G.z); E->G.x = NULL; E->G.y = NULL; E->G.z = NULL; ec->n = E->n; E->n = NULL; ec->h = E->h; ec->name = E->name; /* Now that we know the curve name we can look for the public key Q. point_from_keyparam needs to know the curve parameters so that it is able to use the correct decompression. Parsing the private key D could have been done earlier but it is less surprising if we do it here as well. */ if (keyparam) { int is_opaque_bytes = ((ec->dialect == ECC_DIALECT_ED25519 && (flags & PUBKEY_FLAG_EDDSA)) || (ec->dialect == ECC_DIALECT_SAFECURVE)); errc = point_from_keyparam (&ec->Q, keyparam, "q", ec); if (errc) return errc; errc = mpi_from_keyparam (&ec->d, keyparam, "d", is_opaque_bytes); /* Size of opaque bytes should match size of P. */ if (ec->d && is_opaque_bytes) { unsigned int n = mpi_get_nbits (ec->d); + unsigned int len; - if ((n+7)/8 != (ec->nbits+7)/8) + len = (ec->nbits%8) == 0 ? (ec->nbits/8 + 1) : (ec->nbits+7)/8; + + if ((n+7)/8 != len) { if (DBG_CIPHER) log_debug ("scalar size (%d) != prime size (%d)", - (n+7)/8, (ec->nbits+7)/8); + (n+7)/8, len); errc = GPG_ERR_INV_OBJ; } } } return errc; } gpg_err_code_t _gcry_mpi_ec_internal_new (mpi_ec_t *r_ec, int *r_flags, const char *name_op, gcry_sexp_t keyparam, const char *curvename) { gpg_err_code_t errc; elliptic_curve_t E; mpi_ec_t ec; *r_ec = NULL; memset (&E, 0, sizeof E); errc = mpi_ec_get_elliptic_curve (&E, r_flags, keyparam, curvename); if (errc) goto leave; ec = _gcry_mpi_ec_p_internal_new (E.model, E.dialect, *r_flags, E.p, E.a, E.b); if (!ec) goto leave; errc = mpi_ec_setup_elliptic_curve (ec, *r_flags, &E, keyparam); if (errc) { _gcry_mpi_ec_free (ec); goto leave; } else *r_ec = ec; if (!errc && DBG_CIPHER) { gcry_mpi_t mpi_q = NULL; gcry_sexp_t l1; char msg[80]; l1 = sexp_find_token (keyparam, "q", 0); if (l1) { mpi_q = sexp_nth_mpi (l1, 1, GCRYMPI_FMT_OPAQUE); sexp_release (l1); } log_debug ("%s info: %s/%s%s\n", name_op, _gcry_ecc_model2str (ec->model), _gcry_ecc_dialect2str (ec->dialect), (*r_flags & PUBKEY_FLAG_EDDSA)? "+EdDSA" : ""); if (ec->name) log_debug ("%s name: %s\n", name_op, ec->name); snprintf (msg, sizeof msg, "%s p", name_op); log_printmpi (msg, ec->p); snprintf (msg, sizeof msg, "%s a", name_op); log_printmpi (msg, ec->a); snprintf (msg, sizeof msg, "%s b", name_op); log_printmpi (msg, ec->b); snprintf (msg, sizeof msg, "%s g", name_op); log_printpnt (msg, ec->G, NULL); snprintf (msg, sizeof msg, "%s n", name_op); log_printmpi (msg, ec->n); log_debug ("%s h:+%02x\n", name_op, ec->h); if (mpi_q) { snprintf (msg, sizeof msg, "%s q", name_op); log_printmpi (msg, mpi_q); mpi_free (mpi_q); } if (!fips_mode () && ec->d) { snprintf (msg, sizeof msg, "%s d", name_op); log_printmpi (msg, ec->d); } } leave: _gcry_ecc_curve_free (&E); return errc; } /* This function creates a new context for elliptic curve operations. Either KEYPARAM or CURVENAME must be given. If both are given and KEYPARAM has no curve parameter, CURVENAME is used to add missing parameters. On success 0 is returned and the new context stored at R_CTX. On error NULL is stored at R_CTX and an error code is returned. The context needs to be released using gcry_ctx_release. */ gpg_err_code_t _gcry_mpi_ec_new (gcry_ctx_t *r_ctx, gcry_sexp_t keyparam, const char *curvename) { gpg_err_code_t errc; elliptic_curve_t E; gcry_ctx_t ctx = NULL; int flags = 0; mpi_ec_t ec; *r_ctx = NULL; memset (&E, 0, sizeof E); errc = mpi_ec_get_elliptic_curve (&E, &flags, keyparam, curvename); if (errc) goto leave; errc = _gcry_mpi_ec_p_new (&ctx, E.model, E.dialect, flags, E.p, E.a, E.b); if (errc) goto leave; ec = _gcry_ctx_get_pointer (ctx, CONTEXT_TYPE_EC); errc = mpi_ec_setup_elliptic_curve (ec, flags, &E, keyparam); if (errc) goto leave; *r_ctx = ctx; ctx = NULL; leave: _gcry_ecc_curve_free (&E); _gcry_ctx_release (ctx); return errc; } /* Return the parameters of the curve NAME as an S-expression. */ gcry_sexp_t _gcry_ecc_get_param_sexp (const char *name) { unsigned int nbits; elliptic_curve_t E; mpi_ec_t ctx; gcry_mpi_t g_x, g_y; gcry_mpi_t pkey[5]; gcry_sexp_t result; int i; memset (&E, 0, sizeof E); if (_gcry_ecc_fill_in_curve (0, name, &E, &nbits)) return NULL; g_x = mpi_new (0); g_y = mpi_new (0); ctx = _gcry_mpi_ec_p_internal_new (E.model, E.dialect, 0, E.p, E.a, E.b); if (_gcry_mpi_ec_get_affine (g_x, g_y, &E.G, ctx)) log_fatal ("ecc get param: Failed to get affine coordinates\n"); _gcry_mpi_ec_free (ctx); _gcry_mpi_point_free_parts (&E.G); pkey[0] = E.p; pkey[1] = E.a; pkey[2] = E.b; pkey[3] = _gcry_ecc_ec2os (g_x, g_y, E.p); pkey[4] = E.n; mpi_free (g_x); mpi_free (g_y); if (sexp_build (&result, NULL, "(public-key(ecc(p%m)(a%m)(b%m)(g%m)(n%m)(h%u)))", pkey[0], pkey[1], pkey[2], pkey[3], pkey[4], E.h)) result = NULL; for (i=0; i < DIM (pkey); i++) _gcry_mpi_release (pkey[i]); return result; } /* Return an MPI (or opaque MPI) described by NAME and the context EC. If COPY is true a copy is returned, if not a const MPI may be returned. In any case mpi_free must be used. */ gcry_mpi_t _gcry_ecc_get_mpi (const char *name, mpi_ec_t ec, int copy) { if (!*name) return NULL; if (!strcmp (name, "p") && ec->p) return mpi_is_const (ec->p) && !copy? ec->p : mpi_copy (ec->p); if (!strcmp (name, "a") && ec->a) return mpi_is_const (ec->a) && !copy? ec->a : mpi_copy (ec->a); if (!strcmp (name, "b") && ec->b) return mpi_is_const (ec->b) && !copy? ec->b : mpi_copy (ec->b); if (!strcmp (name, "n") && ec->n) return mpi_is_const (ec->n) && !copy? ec->n : mpi_copy (ec->n); if (!strcmp (name, "h")) { gcry_mpi_t h = _gcry_mpi_get_const (ec->h); return !copy? h : mpi_set (NULL, h); } if (!strcmp (name, "d") && ec->d) return mpi_is_const (ec->d) && !copy? ec->d : mpi_copy (ec->d); /* Return a requested point coordinate. */ if (!strcmp (name, "g.x") && ec->G && ec->G->x) return mpi_is_const (ec->G->x) && !copy? ec->G->x : mpi_copy (ec->G->x); if (!strcmp (name, "g.y") && ec->G && ec->G->y) return mpi_is_const (ec->G->y) && !copy? ec->G->y : mpi_copy (ec->G->y); if (!strcmp (name, "q.x") && ec->Q && ec->Q->x) return mpi_is_const (ec->Q->x) && !copy? ec->Q->x : mpi_copy (ec->Q->x); if (!strcmp (name, "q.y") && ec->Q && ec->Q->y) return mpi_is_const (ec->Q->y) && !copy? ec->Q->y : mpi_copy (ec->Q->y); /* If the base point has been requested, return it in standard encoding. */ if (!strcmp (name, "g") && ec->G) return _gcry_mpi_ec_ec2os (ec->G, ec); /* If the public key has been requested, return it by default in standard uncompressed encoding or if requested in other encodings. */ if (*name == 'q' && (!name[1] || name[1] == '@')) { /* If only the private key is given, compute the public key. */ if (!ec->Q) ec->Q = _gcry_ecc_compute_public (NULL, ec); if (!ec->Q) return NULL; if (name[1] != '@') return _gcry_mpi_ec_ec2os (ec->Q, ec); if (!strcmp (name+2, "eddsa") && ec->model == MPI_EC_EDWARDS) { unsigned char *encpk; unsigned int encpklen; if (!_gcry_ecc_eddsa_encodepoint (ec->Q, ec, NULL, NULL, 0, &encpk, &encpklen)) return mpi_set_opaque (NULL, encpk, encpklen*8); } } return NULL; } /* Return a point described by NAME and the context EC. */ gcry_mpi_point_t _gcry_ecc_get_point (const char *name, mpi_ec_t ec) { if (!strcmp (name, "g") && ec->G) return point_copy (ec->G); if (!strcmp (name, "q")) { /* If only the private key is given, compute the public key. */ if (!ec->Q) ec->Q = _gcry_ecc_compute_public (NULL, ec); if (ec->Q) return point_copy (ec->Q); } return NULL; } /* Store the MPI NEWVALUE into the context EC under NAME. */ gpg_err_code_t _gcry_ecc_set_mpi (const char *name, gcry_mpi_t newvalue, mpi_ec_t ec) { gpg_err_code_t rc = 0; if (!*name) ; else if (!strcmp (name, "p")) { mpi_free (ec->p); ec->p = mpi_copy (newvalue); _gcry_mpi_ec_get_reset (ec); } else if (!strcmp (name, "a")) { mpi_free (ec->a); ec->a = mpi_copy (newvalue); _gcry_mpi_ec_get_reset (ec); } else if (!strcmp (name, "b")) { mpi_free (ec->b); ec->b = mpi_copy (newvalue); } else if (!strcmp (name, "n")) { mpi_free (ec->n); ec->n = mpi_copy (newvalue); } else if (!strcmp (name, "h")) { mpi_get_ui (&ec->h, newvalue); } else if (*name == 'q' && (!name[1] || name[1] == '@')) { if (newvalue) { if (!ec->Q) ec->Q = mpi_point_new (0); rc = _gcry_mpi_ec_decode_point (ec->Q, newvalue, ec); } if (rc || !newvalue) { _gcry_mpi_point_release (ec->Q); ec->Q = NULL; } /* Note: We assume that Q matches d and thus do not reset d. */ } else if (!strcmp (name, "d")) { mpi_free (ec->d); ec->d = mpi_copy (newvalue); if (ec->d) { /* We need to reset the public key because it may not anymore match. */ _gcry_mpi_point_release (ec->Q); ec->Q = NULL; } } else rc = GPG_ERR_UNKNOWN_NAME; return rc; } /* Store the point NEWVALUE into the context EC under NAME. */ gpg_err_code_t _gcry_ecc_set_point (const char *name, gcry_mpi_point_t newvalue, mpi_ec_t ec) { if (!strcmp (name, "g")) { _gcry_mpi_point_release (ec->G); ec->G = point_copy (newvalue); } else if (!strcmp (name, "q")) { _gcry_mpi_point_release (ec->Q); ec->Q = point_copy (newvalue); } else return GPG_ERR_UNKNOWN_NAME; return 0; } diff --git a/cipher/ecc-eddsa.c b/cipher/ecc-eddsa.c index 2405a3be..2d4eab51 100644 --- a/cipher/ecc-eddsa.c +++ b/cipher/ecc-eddsa.c @@ -1,833 +1,827 @@ /* ecc-eddsa.c - Elliptic Curve EdDSA signatures * Copyright (C) 2013, 2014 g10 Code GmbH * * This file is part of Libgcrypt. * * Libgcrypt is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * Libgcrypt is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program; if not, see . */ #include #include #include #include #include #include "g10lib.h" #include "mpi.h" #include "cipher.h" #include "context.h" #include "ec-context.h" #include "ecc-common.h" void reverse_buffer (unsigned char *buffer, unsigned int length) { unsigned int tmp, i; for (i=0; i < length/2; i++) { tmp = buffer[i]; buffer[i] = buffer[length-1-i]; buffer[length-1-i] = tmp; } } /* Helper to scan a hex string. */ static gcry_mpi_t scanval (const char *string) { gpg_err_code_t rc; gcry_mpi_t val; rc = _gcry_mpi_scan (&val, GCRYMPI_FMT_HEX, string, 0, NULL); if (rc) log_fatal ("scanning ECC parameter failed: %s\n", gpg_strerror (rc)); return val; } /* Encode MPI using the EdDSA scheme. MINLEN specifies the required length of the buffer in bytes. On success 0 is returned an a malloced buffer with the encoded point is stored at R_BUFFER; the length of this buffer is stored at R_BUFLEN. */ static gpg_err_code_t -eddsa_encodempi (gcry_mpi_t mpi, unsigned int minlen, +eddsa_encodempi (gcry_mpi_t mpi, unsigned int nbits, unsigned char **r_buffer, unsigned int *r_buflen) { unsigned char *rawmpi; unsigned int rawmpilen; + unsigned int minlen = (nbits%8) == 0 ? (nbits/8 + 1): (nbits+7)/8; rawmpi = _gcry_mpi_get_buffer (mpi, minlen, &rawmpilen, NULL); if (!rawmpi) return gpg_err_code_from_syserror (); *r_buffer = rawmpi; *r_buflen = rawmpilen; return 0; } -/* Encode (X,Y) using the EdDSA scheme. MINLEN is the required length - in bytes for the result. If WITH_PREFIX is set the returned buffer - is prefixed with a 0x40 byte. On success 0 is returned and a - malloced buffer with the encoded point is stored at R_BUFFER; the +/* Encode (X,Y) using the EdDSA scheme. NBITS is the number of bits + of the field of the curve. If WITH_PREFIX is set the returned + buffer is prefixed with a 0x40 byte. On success 0 is returned and + a malloced buffer with the encoded point is stored at R_BUFFER; the length of this buffer is stored at R_BUFLEN. */ static gpg_err_code_t -eddsa_encode_x_y (gcry_mpi_t x, gcry_mpi_t y, unsigned int minlen, +eddsa_encode_x_y (gcry_mpi_t x, gcry_mpi_t y, unsigned int nbits, int with_prefix, unsigned char **r_buffer, unsigned int *r_buflen) { unsigned char *rawmpi; unsigned int rawmpilen; int off = with_prefix? 1:0; + unsigned int minlen = (nbits%8) == 0 ? (nbits/8 + 1): (nbits+7)/8; rawmpi = _gcry_mpi_get_buffer_extra (y, minlen, off?-1:0, &rawmpilen, NULL); if (!rawmpi) return gpg_err_code_from_syserror (); if (mpi_test_bit (x, 0) && rawmpilen) rawmpi[off + rawmpilen - 1] |= 0x80; /* Set sign bit. */ if (off) rawmpi[0] = 0x40; *r_buffer = rawmpi; *r_buflen = rawmpilen + off; return 0; } /* Encode POINT using the EdDSA scheme. X and Y are either scratch variables supplied by the caller or NULL. CTX is the usual context. If WITH_PREFIX is set the returned buffer is prefixed with a 0x40 byte. On success 0 is returned and a malloced buffer with the encoded point is stored at R_BUFFER; the length of this buffer is stored at R_BUFLEN. */ gpg_err_code_t _gcry_ecc_eddsa_encodepoint (mpi_point_t point, mpi_ec_t ec, gcry_mpi_t x_in, gcry_mpi_t y_in, int with_prefix, unsigned char **r_buffer, unsigned int *r_buflen) { gpg_err_code_t rc; gcry_mpi_t x, y; x = x_in? x_in : mpi_new (0); y = y_in? y_in : mpi_new (0); if (_gcry_mpi_ec_get_affine (x, y, point, ec)) { log_error ("eddsa_encodepoint: Failed to get affine coordinates\n"); rc = GPG_ERR_INTERNAL; } else - rc = eddsa_encode_x_y (x, y, (ec->nbits+7)/8, with_prefix, r_buffer, r_buflen); + rc = eddsa_encode_x_y (x, y, ec->nbits, with_prefix, r_buffer, r_buflen); if (!x_in) mpi_free (x); if (!y_in) mpi_free (y); return rc; } /* Make sure that the opaque MPI VALUE is in compact EdDSA format. This function updates MPI if needed. */ gpg_err_code_t _gcry_ecc_eddsa_ensure_compact (gcry_mpi_t value, unsigned int nbits) { gpg_err_code_t rc; const unsigned char *buf; unsigned int rawmpilen; gcry_mpi_t x, y; unsigned char *enc; unsigned int enclen; if (!mpi_is_opaque (value)) return GPG_ERR_INV_OBJ; buf = mpi_get_opaque (value, &rawmpilen); if (!buf) return GPG_ERR_INV_OBJ; rawmpilen = (rawmpilen + 7)/8; if (rawmpilen > 1 && (rawmpilen%2)) { if (buf[0] == 0x04) { /* Buffer is in SEC1 uncompressed format. Extract y and compress. */ rc = _gcry_mpi_scan (&x, GCRYMPI_FMT_USG, buf+1, (rawmpilen-1)/2, NULL); if (rc) return rc; rc = _gcry_mpi_scan (&y, GCRYMPI_FMT_USG, buf+1+(rawmpilen-1)/2, (rawmpilen-1)/2, NULL); if (rc) { mpi_free (x); return rc; } - rc = eddsa_encode_x_y (x, y, (nbits+7)/8, 0, &enc, &enclen); + rc = eddsa_encode_x_y (x, y, nbits, 0, &enc, &enclen); mpi_free (x); mpi_free (y); if (rc) return rc; mpi_set_opaque (value, enc, 8*enclen); } else if (buf[0] == 0x40) { /* Buffer is compressed but with our SEC1 alike compression indicator. Remove that byte. FIXME: We should write and use a function to manipulate an opaque MPI in place. */ if (!_gcry_mpi_set_opaque_copy (value, buf + 1, (rawmpilen - 1)*8)) return gpg_err_code_from_syserror (); } } return 0; } /* Recover X from Y and SIGN (which actually is a parity bit). */ gpg_err_code_t _gcry_ecc_eddsa_recover_x (gcry_mpi_t x, gcry_mpi_t y, int sign, mpi_ec_t ec) { gpg_err_code_t rc = 0; gcry_mpi_t u, v, v3, t; static gcry_mpi_t p58, seven; if (ec->dialect != ECC_DIALECT_ED25519) return GPG_ERR_NOT_IMPLEMENTED; if (!p58) p58 = scanval ("0FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF" "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFD"); if (!seven) seven = mpi_set_ui (NULL, 7); u = mpi_new (0); v = mpi_new (0); v3 = mpi_new (0); t = mpi_new (0); /* Compute u and v */ /* u = y^2 */ mpi_mulm (u, y, y, ec->p); /* v = b*y^2 */ mpi_mulm (v, ec->b, u, ec->p); /* u = y^2-1 */ mpi_sub_ui (u, u, 1); /* v = b*y^2+1 */ mpi_add_ui (v, v, 1); /* Compute sqrt(u/v) */ /* v3 = v^3 */ mpi_powm (v3, v, mpi_const (MPI_C_THREE), ec->p); /* t = v3 * v3 * u * v = u * v^7 */ mpi_powm (t, v, seven, ec->p); mpi_mulm (t, t, u, ec->p); /* t = t^((p-5)/8) = (u * v^7)^((p-5)/8) */ mpi_powm (t, t, p58, ec->p); /* x = t * u * v^3 = (u * v^3) * (u * v^7)^((p-5)/8) */ mpi_mulm (t, t, u, ec->p); mpi_mulm (x, t, v3, ec->p); /* Adjust if needed. */ /* t = v * x^2 */ mpi_mulm (t, x, x, ec->p); mpi_mulm (t, t, v, ec->p); /* -t == u ? x = x * sqrt(-1) */ mpi_sub (t, ec->p, t); if (!mpi_cmp (t, u)) { static gcry_mpi_t m1; /* Fixme: this is not thread-safe. */ if (!m1) m1 = scanval ("2B8324804FC1DF0B2B4D00993DFBD7A7" "2F431806AD2FE478C4EE1B274A0EA0B0"); mpi_mulm (x, x, m1, ec->p); /* t = v * x^2 */ mpi_mulm (t, x, x, ec->p); mpi_mulm (t, t, v, ec->p); /* -t == u ? x = x * sqrt(-1) */ mpi_sub (t, ec->p, t); if (!mpi_cmp (t, u)) rc = GPG_ERR_INV_OBJ; } /* Choose the desired square root according to parity */ if (mpi_test_bit (x, 0) != !!sign) mpi_sub (x, ec->p, x); mpi_free (t); mpi_free (v3); mpi_free (v); mpi_free (u); return rc; } /* Decode the EdDSA style encoded PK and set it into RESULT. CTX is the usual curve context. If R_ENCPK is not NULL, the encoded PK is stored at that address; this is a new copy to be released by the caller. In contrast to the supplied PK, this is not an MPI and thus guaranteed to be properly padded. R_ENCPKLEN receives the length of that encoded key. */ gpg_err_code_t _gcry_ecc_eddsa_decodepoint (gcry_mpi_t pk, mpi_ec_t ctx, mpi_point_t result, unsigned char **r_encpk, unsigned int *r_encpklen) { gpg_err_code_t rc; unsigned char *rawmpi; unsigned int rawmpilen; int sign; if (mpi_is_opaque (pk)) { const unsigned char *buf; buf = mpi_get_opaque (pk, &rawmpilen); if (!buf) return GPG_ERR_INV_OBJ; rawmpilen = (rawmpilen + 7)/8; if (!(rawmpilen == (ctx->nbits+7)/8 || rawmpilen == (ctx->nbits+7)/8 + 1 || rawmpilen == (ctx->nbits+7)/8 * 2 + 1)) return GPG_ERR_INV_OBJ; /* Handle compression prefixes. The size of the buffer will be odd in this case. */ if (rawmpilen > 1 && (rawmpilen%2)) { /* First check whether the public key has been given in standard uncompressed format (SEC1). No need to recover x in this case. */ if (buf[0] == 0x04) { gcry_mpi_t x, y; rc = _gcry_mpi_scan (&x, GCRYMPI_FMT_USG, buf+1, (rawmpilen-1)/2, NULL); if (rc) return rc; rc = _gcry_mpi_scan (&y, GCRYMPI_FMT_USG, buf+1+(rawmpilen-1)/2, (rawmpilen-1)/2,NULL); if (rc) { mpi_free (x); return rc; } if (r_encpk) { - rc = eddsa_encode_x_y (x, y, (ctx->nbits+7)/8, 0, + rc = eddsa_encode_x_y (x, y, ctx->nbits, 0, r_encpk, r_encpklen); if (rc) { mpi_free (x); mpi_free (y); return rc; } } mpi_snatch (result->x, x); mpi_snatch (result->y, y); mpi_set_ui (result->z, 1); return 0; } /* Check whether the public key has been prefixed with a 0x40 byte to explicitly indicate compressed format using a SEC1 alike prefix byte. This is a Libgcrypt extension. */ if (buf[0] == 0x40) { rawmpilen--; buf++; } } /* EdDSA compressed point. */ rawmpi = xtrymalloc (rawmpilen); if (!rawmpi) return gpg_err_code_from_syserror (); memcpy (rawmpi, buf, rawmpilen); reverse_buffer (rawmpi, rawmpilen); } else { /* Note: Without using an opaque MPI it is not reliable possible to find out whether the public key has been given in uncompressed format. Thus we expect native EdDSA format. */ rawmpi = _gcry_mpi_get_buffer (pk, (ctx->nbits+7)/8, &rawmpilen, NULL); if (!rawmpi) return gpg_err_code_from_syserror (); } if (rawmpilen) { sign = !!(rawmpi[0] & 0x80); rawmpi[0] &= 0x7f; } else sign = 0; _gcry_mpi_set_buffer (result->y, rawmpi, rawmpilen, 0); if (r_encpk) { /* Revert to little endian. */ if (sign && rawmpilen) rawmpi[0] |= 0x80; reverse_buffer (rawmpi, rawmpilen); *r_encpk = rawmpi; if (r_encpklen) *r_encpklen = rawmpilen; } else xfree (rawmpi); rc = _gcry_ecc_eddsa_recover_x (result->x, result->y, sign, ctx); mpi_set_ui (result->z, 1); return rc; } /* Compute the A value as used by EdDSA. The caller needs to provide the context EC and the actual secret D as an MPI. The function returns a newly allocated 64 byte buffer at r_digest; the first 32 bytes represent the A value. NULL is returned on error and NULL stored at R_DIGEST. */ gpg_err_code_t _gcry_ecc_eddsa_compute_h_d (unsigned char **r_digest, mpi_ec_t ec) { gpg_err_code_t rc; unsigned char *rawmpi = NULL; unsigned int rawmpilen; unsigned char *digest; gcry_buffer_t hvec[2]; int hashalgo, b; *r_digest = NULL; hashalgo = GCRY_MD_SHA512; if (hashalgo != GCRY_MD_SHA512) return GPG_ERR_DIGEST_ALGO; b = (ec->nbits+7)/8; if (b != 256/8) return GPG_ERR_INTERNAL; /* We only support 256 bit. */ /* Note that we clear DIGEST so we can use it as input to left pad the key with zeroes for hashing. */ digest = xtrycalloc_secure (2, b); if (!digest) return gpg_err_code_from_syserror (); memset (hvec, 0, sizeof hvec); rawmpi = _gcry_mpi_get_buffer (ec->d, 0, &rawmpilen, NULL); if (!rawmpi) { xfree (digest); return gpg_err_code_from_syserror (); } hvec[0].data = digest; hvec[0].off = 0; hvec[0].len = b > rawmpilen? b - rawmpilen : 0; hvec[1].data = rawmpi; hvec[1].off = 0; hvec[1].len = rawmpilen; rc = _gcry_md_hash_buffers (hashalgo, 0, digest, hvec, 2); xfree (rawmpi); if (rc) { xfree (digest); return rc; } /* Compute the A value. */ reverse_buffer (digest, 32); /* Only the first half of the hash. */ digest[0] = (digest[0] & 0x7f) | 0x40; digest[31] &= 0xf8; *r_digest = digest; return 0; } /** * _gcry_ecc_eddsa_genkey - EdDSA version of the key generation. * * @ec: Elliptic curve computation context. * @flags: Flags controlling aspects of the creation. * * Return: An error code. * * The only @flags bit used by this function is %PUBKEY_FLAG_TRANSIENT * to use a faster RNG. */ gpg_err_code_t _gcry_ecc_eddsa_genkey (mpi_ec_t ec, int flags) { gpg_err_code_t rc; int b = 256/8; /* The only size we currently support. */ gcry_mpi_t a, x, y; mpi_point_struct Q; gcry_random_level_t random_level; char *dbuf; size_t dlen; gcry_buffer_t hvec[1]; unsigned char *hash_d = NULL; point_init (&Q); memset (hvec, 0, sizeof hvec); if ((flags & PUBKEY_FLAG_TRANSIENT_KEY)) random_level = GCRY_STRONG_RANDOM; else random_level = GCRY_VERY_STRONG_RANDOM; a = mpi_snew (0); x = mpi_new (0); y = mpi_new (0); /* Generate a secret. */ hash_d = xtrymalloc_secure (2*b); if (!hash_d) { rc = gpg_err_code_from_syserror (); goto leave; } dlen = b; dbuf = _gcry_random_bytes_secure (dlen, random_level); /* Compute the A value. */ hvec[0].data = dbuf; hvec[0].len = dlen; rc = _gcry_md_hash_buffers (GCRY_MD_SHA512, 0, hash_d, hvec, 1); if (rc) goto leave; ec->d = _gcry_mpi_set_opaque (NULL, dbuf, dlen*8); dbuf = NULL; reverse_buffer (hash_d, 32); /* Only the first half of the hash. */ hash_d[0] = (hash_d[0] & 0x7f) | 0x40; hash_d[31] &= 0xf8; _gcry_mpi_set_buffer (a, hash_d, 32, 0); xfree (hash_d); hash_d = NULL; /* log_printmpi ("ecgen a", a); */ /* Compute Q. */ _gcry_mpi_ec_mul_point (&Q, a, ec->G, ec); if (DBG_CIPHER) log_printpnt ("ecgen pk", &Q, ec); ec->Q = mpi_point_snatch_set (NULL, Q.x, Q.y, Q.z); Q.x = NULL; Q.y = NULL; Q.x = NULL; leave: _gcry_mpi_release (a); _gcry_mpi_release (x); _gcry_mpi_release (y); xfree (hash_d); return rc; } /* Compute an EdDSA signature. See: * [ed25519] 23pp. (PDF) Daniel J. Bernstein, Niels Duif, Tanja * Lange, Peter Schwabe, Bo-Yin Yang. High-speed high-security * signatures. Journal of Cryptographic Engineering 2 (2012), 77-89. * Document ID: a1a62a2f76d23f65d622484ddd09caf8. * URL: http://cr.yp.to/papers.html#ed25519. Date: 2011.09.26. * * Despite that this function requires the specification of a hash * algorithm, we only support what has been specified by the paper. * This may change in the future. Note that we don't check the used * curve; the user is responsible to use Ed25519. * * Return the signature struct (r,s) from the message hash. The caller * must have allocated R_R and S. */ gpg_err_code_t _gcry_ecc_eddsa_sign (gcry_mpi_t input, mpi_ec_t ec, gcry_mpi_t r_r, gcry_mpi_t s, int hashalgo) { int rc; - int b; unsigned int tmp; unsigned char *digest = NULL; gcry_buffer_t hvec[3]; const void *mbuf; size_t mlen; unsigned char *rawmpi = NULL; unsigned int rawmpilen; unsigned char *encpk = NULL; /* Encoded public key. */ unsigned int encpklen; mpi_point_struct I; /* Intermediate value. */ gcry_mpi_t a, x, y, r; memset (hvec, 0, sizeof hvec); if (!mpi_is_opaque (input)) return GPG_ERR_INV_DATA; /* Initialize some helpers. */ point_init (&I); a = mpi_snew (0); x = mpi_new (0); y = mpi_new (0); r = mpi_snew (0); - b = (ec->nbits+7)/8; - if (b != 256/8) - { - rc = GPG_ERR_INTERNAL; /* We only support 256 bit. */ - goto leave; - } - rc = _gcry_ecc_eddsa_compute_h_d (&digest, ec); if (rc) goto leave; _gcry_mpi_set_buffer (a, digest, 32, 0); /* Compute the public key if it's not available (only secret part). */ if (ec->Q == NULL) { mpi_point_struct Q; point_init (&Q); _gcry_mpi_ec_mul_point (&Q, a, ec->G, ec); ec->Q = mpi_point_snatch_set (NULL, Q.x, Q.y, Q.z); } rc = _gcry_ecc_eddsa_encodepoint (ec->Q, ec, x, y, 0, &encpk, &encpklen); if (rc) goto leave; if (DBG_CIPHER) log_printhex (" e_pk", encpk, encpklen); /* Compute R. */ mbuf = mpi_get_opaque (input, &tmp); mlen = (tmp +7)/8; if (DBG_CIPHER) log_printhex (" m", mbuf, mlen); hvec[0].data = digest; hvec[0].off = 32; hvec[0].len = 32; hvec[1].data = (char*)mbuf; hvec[1].len = mlen; rc = _gcry_md_hash_buffers (hashalgo, 0, digest, hvec, 2); if (rc) goto leave; reverse_buffer (digest, 64); if (DBG_CIPHER) log_printhex (" r", digest, 64); _gcry_mpi_set_buffer (r, digest, 64, 0); _gcry_mpi_ec_mul_point (&I, r, ec->G, ec); if (DBG_CIPHER) log_printpnt (" r", &I, ec); /* Convert R into affine coordinates and apply encoding. */ rc = _gcry_ecc_eddsa_encodepoint (&I, ec, x, y, 0, &rawmpi, &rawmpilen); if (rc) goto leave; if (DBG_CIPHER) log_printhex (" e_r", rawmpi, rawmpilen); /* S = r + a * H(encodepoint(R) + encodepoint(pk) + m) mod n */ hvec[0].data = rawmpi; /* (this is R) */ hvec[0].off = 0; hvec[0].len = rawmpilen; hvec[1].data = encpk; hvec[1].off = 0; hvec[1].len = encpklen; hvec[2].data = (char*)mbuf; hvec[2].off = 0; hvec[2].len = mlen; rc = _gcry_md_hash_buffers (hashalgo, 0, digest, hvec, 3); if (rc) goto leave; /* No more need for RAWMPI thus we now transfer it to R_R. */ mpi_set_opaque (r_r, rawmpi, rawmpilen*8); rawmpi = NULL; reverse_buffer (digest, 64); if (DBG_CIPHER) log_printhex (" H(R+)", digest, 64); _gcry_mpi_set_buffer (s, digest, 64, 0); mpi_mulm (s, s, a, ec->n); mpi_addm (s, s, r, ec->n); - rc = eddsa_encodempi (s, b, &rawmpi, &rawmpilen); + rc = eddsa_encodempi (s, ec->nbits, &rawmpi, &rawmpilen); if (rc) goto leave; if (DBG_CIPHER) log_printhex (" e_s", rawmpi, rawmpilen); mpi_set_opaque (s, rawmpi, rawmpilen*8); rawmpi = NULL; rc = 0; leave: _gcry_mpi_release (a); _gcry_mpi_release (x); _gcry_mpi_release (y); _gcry_mpi_release (r); xfree (digest); point_free (&I); xfree (encpk); xfree (rawmpi); return rc; } /* Verify an EdDSA signature. See sign_eddsa for the reference. * Check if R_IN and S_IN verifies INPUT. */ gpg_err_code_t _gcry_ecc_eddsa_verify (gcry_mpi_t input, mpi_ec_t ec, gcry_mpi_t r_in, gcry_mpi_t s_in, int hashalgo) { int rc; int b; unsigned int tmp; unsigned char *encpk = NULL; /* Encoded public key. */ unsigned int encpklen; const void *mbuf, *rbuf; unsigned char *tbuf = NULL; size_t mlen, rlen; unsigned int tlen; unsigned char digest[64]; gcry_buffer_t hvec[3]; gcry_mpi_t h, s; mpi_point_struct Ia, Ib; if (!mpi_is_opaque (input) || !mpi_is_opaque (r_in) || !mpi_is_opaque (s_in)) return GPG_ERR_INV_DATA; if (hashalgo != GCRY_MD_SHA512) return GPG_ERR_DIGEST_ALGO; point_init (&Ia); point_init (&Ib); h = mpi_new (0); s = mpi_new (0); b = (ec->nbits+7)/8; if (b != 256/8) { rc = GPG_ERR_INTERNAL; /* We only support 256 bit. */ goto leave; } /* Encode and check the public key. */ rc = _gcry_ecc_eddsa_encodepoint (ec->Q, ec, NULL, NULL, 0, &encpk, &encpklen); if (rc) goto leave; if (!_gcry_mpi_ec_curve_point (ec->Q, ec)) { rc = GPG_ERR_BROKEN_PUBKEY; goto leave; } if (DBG_CIPHER) log_printhex (" e_pk", encpk, encpklen); if (encpklen != b) { rc = GPG_ERR_INV_LENGTH; goto leave; } /* Convert the other input parameters. */ mbuf = mpi_get_opaque (input, &tmp); mlen = (tmp +7)/8; if (DBG_CIPHER) log_printhex (" m", mbuf, mlen); rbuf = mpi_get_opaque (r_in, &tmp); rlen = (tmp +7)/8; if (DBG_CIPHER) log_printhex (" r", rbuf, rlen); if (rlen != b) { rc = GPG_ERR_INV_LENGTH; goto leave; } /* h = H(encodepoint(R) + encodepoint(pk) + m) */ hvec[0].data = (char*)rbuf; hvec[0].off = 0; hvec[0].len = rlen; hvec[1].data = encpk; hvec[1].off = 0; hvec[1].len = encpklen; hvec[2].data = (char*)mbuf; hvec[2].off = 0; hvec[2].len = mlen; rc = _gcry_md_hash_buffers (hashalgo, 0, digest, hvec, 3); if (rc) goto leave; reverse_buffer (digest, 64); if (DBG_CIPHER) log_printhex (" H(R+)", digest, 64); _gcry_mpi_set_buffer (h, digest, 64, 0); /* According to the paper the best way for verification is: encodepoint(sG - h·Q) = encodepoint(r) because we don't need to decode R. */ { void *sbuf; unsigned int slen; sbuf = _gcry_mpi_get_opaque_copy (s_in, &tmp); slen = (tmp +7)/8; reverse_buffer (sbuf, slen); if (DBG_CIPHER) log_printhex (" s", sbuf, slen); _gcry_mpi_set_buffer (s, sbuf, slen, 0); xfree (sbuf); if (slen != b) { rc = GPG_ERR_INV_LENGTH; goto leave; } } _gcry_mpi_ec_mul_point (&Ia, s, ec->G, ec); _gcry_mpi_ec_mul_point (&Ib, h, ec->Q, ec); _gcry_mpi_sub (Ib.x, ec->p, Ib.x); _gcry_mpi_ec_add_points (&Ia, &Ia, &Ib, ec); rc = _gcry_ecc_eddsa_encodepoint (&Ia, ec, s, h, 0, &tbuf, &tlen); if (rc) goto leave; if (tlen != rlen || memcmp (tbuf, rbuf, tlen)) { rc = GPG_ERR_BAD_SIGNATURE; goto leave; } rc = 0; leave: xfree (encpk); xfree (tbuf); _gcry_mpi_release (s); _gcry_mpi_release (h); point_free (&Ia); point_free (&Ib); return rc; }