diff options
Diffstat (limited to 'grub-core/lib/libgcrypt-grub/cipher/dsa.c')
| -rw-r--r-- | grub-core/lib/libgcrypt-grub/cipher/dsa.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/grub-core/lib/libgcrypt-grub/cipher/dsa.c b/grub-core/lib/libgcrypt-grub/cipher/dsa.c new file mode 100644 index 0000000..52079c5 --- /dev/null +++ b/grub-core/lib/libgcrypt-grub/cipher/dsa.c @@ -0,0 +1,292 @@ +/* This file was automatically imported with + import_gcry.py. Please don't modify it */ +#include <grub/dl.h> +GRUB_MOD_LICENSE ("GPLv3+"); +/* dsa.c - DSA signature algorithm + * Copyright (C) 1998, 2000, 2001, 2002, 2003, + * 2006, 2008 Free Software Foundation, Inc. + * + * 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 <http://www.gnu.org/licenses/>. + */ + + +#include "g10lib.h" +#include "mpi.h" +#include "cipher.h" + +typedef struct +{ + gcry_mpi_t p; /* prime */ + gcry_mpi_t q; /* group order */ + gcry_mpi_t g; /* group generator */ + gcry_mpi_t y; /* g^x mod p */ +} DSA_public_key; + + +typedef struct +{ + gcry_mpi_t p; /* prime */ + gcry_mpi_t q; /* group order */ + gcry_mpi_t g; /* group generator */ + gcry_mpi_t y; /* g^x mod p */ + gcry_mpi_t x; /* secret exponent */ +} DSA_secret_key; + + +/* A structure used to hold domain parameters. */ +typedef struct +{ + gcry_mpi_t p; /* prime */ + gcry_mpi_t q; /* group order */ + gcry_mpi_t g; /* group generator */ +} dsa_domain_t; + + +/* A sample 1024 bit DSA key used for the selftests. */ +/* A sample 1024 bit DSA key used for the selftests (public only). */ + + + + +static int check_secret_key (DSA_secret_key *sk); +static int verify (gcry_mpi_t r, gcry_mpi_t s, gcry_mpi_t input, + DSA_public_key *pkey); + + + + + + + +/* + * Generate a random secret exponent k less than q. + */ + + +/* Check that a freshly generated key actually works. Returns 0 on success. */ + + + +/* + Generate a DSA key pair with a key of size NBITS. If transient_key + is true the key is generated using the standard RNG and not the + very secure one. + + Returns: 2 structures filled with all needed values + and an array with the n-1 factors of (p-1) + */ + + +/* Generate a DSA key pair with a key of size NBITS using the + algorithm given in FIPS-186-3. If USE_FIPS186_2 is true, + FIPS-186-2 is used and thus the length is restricted to 1024/160. + If DERIVEPARMS is not NULL it may contain a seed value. If domain + parameters are specified in DOMAIN, DERIVEPARMS may not be given + and NBITS and QBITS must match the specified domain parameters. */ + + + +/* + Test whether the secret key is valid. + Returns: if this is a valid key. + */ +static int +check_secret_key( DSA_secret_key *sk ) +{ + int rc; + gcry_mpi_t y = mpi_alloc( mpi_get_nlimbs(sk->y) ); + + gcry_mpi_powm( y, sk->g, sk->x, sk->p ); + rc = !mpi_cmp( y, sk->y ); + mpi_free( y ); + return rc; +} + + + +/* + Make a DSA signature from HASH and put it into r and s. + */ + + +/* + Returns true if the signature composed from R and S is valid. + */ +static int +verify (gcry_mpi_t r, gcry_mpi_t s, gcry_mpi_t hash, DSA_public_key *pkey ) +{ + int rc; + gcry_mpi_t w, u1, u2, v; + gcry_mpi_t base[3]; + gcry_mpi_t ex[3]; + + if( !(mpi_cmp_ui( r, 0 ) > 0 && mpi_cmp( r, pkey->q ) < 0) ) + return 0; /* assertion 0 < r < q failed */ + if( !(mpi_cmp_ui( s, 0 ) > 0 && mpi_cmp( s, pkey->q ) < 0) ) + return 0; /* assertion 0 < s < q failed */ + + w = mpi_alloc( mpi_get_nlimbs(pkey->q) ); + u1 = mpi_alloc( mpi_get_nlimbs(pkey->q) ); + u2 = mpi_alloc( mpi_get_nlimbs(pkey->q) ); + v = mpi_alloc( mpi_get_nlimbs(pkey->p) ); + + /* w = s^(-1) mod q */ + mpi_invm( w, s, pkey->q ); + + /* u1 = (hash * w) mod q */ + mpi_mulm( u1, hash, w, pkey->q ); + + /* u2 = r * w mod q */ + mpi_mulm( u2, r, w, pkey->q ); + + /* v = g^u1 * y^u2 mod p mod q */ + base[0] = pkey->g; ex[0] = u1; + base[1] = pkey->y; ex[1] = u2; + base[2] = NULL; ex[2] = NULL; + mpi_mulpowm( v, base, ex, pkey->p ); + mpi_fdiv_r( v, v, pkey->q ); + + rc = !mpi_cmp( v, r ); + + mpi_free(w); + mpi_free(u1); + mpi_free(u2); + mpi_free(v); + + return rc; +} + + +/********************************************* + ************** interface ****************** + *********************************************/ + +#define dsa_generate 0 + +#define dsa_generate 0 + + +static gcry_err_code_t +dsa_check_secret_key (int algo, gcry_mpi_t *skey) +{ + gcry_err_code_t err = GPG_ERR_NO_ERROR; + DSA_secret_key sk; + + (void)algo; + + if ((! skey[0]) || (! skey[1]) || (! skey[2]) || (! skey[3]) || (! skey[4])) + err = GPG_ERR_BAD_MPI; + else + { + sk.p = skey[0]; + sk.q = skey[1]; + sk.g = skey[2]; + sk.y = skey[3]; + sk.x = skey[4]; + if (! check_secret_key (&sk)) + err = GPG_ERR_BAD_SECKEY; + } + + return err; +} + + +#define dsa_sign 0 +static gcry_err_code_t +dsa_verify (int algo, gcry_mpi_t hash, gcry_mpi_t *data, gcry_mpi_t *pkey, + int (*cmp) (void *, gcry_mpi_t), void *opaquev) +{ + gcry_err_code_t err = GPG_ERR_NO_ERROR; + DSA_public_key pk; + + (void)algo; + (void)cmp; + (void)opaquev; + + if ((! data[0]) || (! data[1]) || (! hash) + || (! pkey[0]) || (! pkey[1]) || (! pkey[2]) || (! pkey[3])) + err = GPG_ERR_BAD_MPI; + else + { + pk.p = pkey[0]; + pk.q = pkey[1]; + pk.g = pkey[2]; + pk.y = pkey[3]; + if (! verify (data[0], data[1], hash, &pk)) + err = GPG_ERR_BAD_SIGNATURE; + } + return err; +} + + +static unsigned int +dsa_get_nbits (int algo, gcry_mpi_t *pkey) +{ + (void)algo; + + return mpi_get_nbits (pkey[0]); +} + + + +/* + Self-test section. + */ + + + + + +/* Run a full self-test for ALGO and return 0 on success. */ + + + + +static const char *dsa_names[] = + { + "dsa", + "openpgp-dsa", + NULL, + }; + +gcry_pk_spec_t _gcry_pubkey_spec_dsa = + { + "DSA", dsa_names, + "pqgy", "pqgyx", "", "rs", "pqgy", + GCRY_PK_USAGE_SIGN, + dsa_generate, + dsa_check_secret_key, + NULL, + NULL, + dsa_sign, + dsa_verify, + dsa_get_nbits + , +#ifdef GRUB_UTIL + .modname = "gcry_dsa", +#endif + }; + + +GRUB_MOD_INIT(gcry_dsa) +{ + grub_crypto_pk_dsa = &_gcry_pubkey_spec_dsa; +} + +GRUB_MOD_FINI(gcry_dsa) +{ + grub_crypto_pk_dsa = 0; +} |