Annotation of embedaddon/strongswan/src/libstrongswan/plugins/pkcs11/pkcs11_dh.c, revision 1.1
1.1 ! misho 1: /*
! 2: * Copyright (C) 2011 Tobias Brunner
! 3: * HSR Hochschule fuer Technik Rapperswil
! 4: *
! 5: * This program is free software; you can redistribute it and/or modify it
! 6: * under the terms of the GNU General Public License as published by the
! 7: * Free Software Foundation; either version 2 of the License, or (at your
! 8: * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
! 9: *
! 10: * This program is distributed in the hope that it will be useful, but
! 11: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
! 12: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
! 13: * for more details.
! 14: */
! 15:
! 16: #include "pkcs11_dh.h"
! 17:
! 18: #include <utils/debug.h>
! 19: #include <library.h>
! 20: #include <asn1/asn1.h>
! 21: #include <asn1/oid.h>
! 22:
! 23: #include "pkcs11_manager.h"
! 24:
! 25: typedef struct private_pkcs11_dh_t private_pkcs11_dh_t;
! 26:
! 27: /**
! 28: * Private data of an pkcs11_dh_t object.
! 29: */
! 30: struct private_pkcs11_dh_t {
! 31:
! 32: /**
! 33: * Public pkcs11_dh_t interface
! 34: */
! 35: pkcs11_dh_t public;
! 36:
! 37: /**
! 38: * PKCS#11 library
! 39: */
! 40: pkcs11_library_t *lib;
! 41:
! 42: /**
! 43: * Session handle for this object
! 44: */
! 45: CK_SESSION_HANDLE session;
! 46:
! 47: /**
! 48: * Diffie Hellman group number.
! 49: */
! 50: diffie_hellman_group_t group;
! 51:
! 52: /**
! 53: * Handle for own private value
! 54: */
! 55: CK_OBJECT_HANDLE pri_key;
! 56:
! 57: /**
! 58: * Own public value
! 59: */
! 60: chunk_t pub_key;
! 61:
! 62: /**
! 63: * Shared secret
! 64: */
! 65: chunk_t secret;
! 66:
! 67: /**
! 68: * Mechanism to use to generate a key pair
! 69: */
! 70: CK_MECHANISM_TYPE mech_key;
! 71:
! 72: /**
! 73: * Mechanism to use to derive a shared secret
! 74: */
! 75: CK_MECHANISM_TYPE mech_derive;
! 76:
! 77: };
! 78:
! 79: /**
! 80: * Derive a DH/ECDH shared secret.
! 81: *
! 82: * If this succeeds the shared secret is stored in this->secret.
! 83: */
! 84: static bool derive_secret(private_pkcs11_dh_t *this, chunk_t other)
! 85: {
! 86: CK_OBJECT_CLASS klass = CKO_SECRET_KEY;
! 87: CK_KEY_TYPE type = CKK_GENERIC_SECRET;
! 88: CK_ATTRIBUTE attr[] = {
! 89: { CKA_CLASS, &klass, sizeof(klass) },
! 90: { CKA_KEY_TYPE, &type, sizeof(type) },
! 91: };
! 92: CK_MECHANISM mech = {
! 93: this->mech_derive,
! 94: other.ptr,
! 95: other.len,
! 96: };
! 97: CK_OBJECT_HANDLE secret;
! 98: CK_RV rv;
! 99:
! 100: rv = this->lib->f->C_DeriveKey(this->session, &mech, this->pri_key,
! 101: attr, countof(attr), &secret);
! 102: if (rv != CKR_OK)
! 103: {
! 104: DBG1(DBG_CFG, "C_DeriveKey() error: %N", ck_rv_names, rv);
! 105: return FALSE;
! 106: }
! 107: if (!this->lib->get_ck_attribute(this->lib, this->session, secret,
! 108: CKA_VALUE, &this->secret))
! 109: {
! 110: chunk_free(&this->secret);
! 111: return FALSE;
! 112: }
! 113: return TRUE;
! 114: }
! 115:
! 116: METHOD(diffie_hellman_t, set_other_public_value, bool,
! 117: private_pkcs11_dh_t *this, chunk_t value)
! 118: {
! 119: if (!diffie_hellman_verify_value(this->group, value))
! 120: {
! 121: return FALSE;
! 122: }
! 123:
! 124: switch (this->group)
! 125: {
! 126: case ECP_192_BIT:
! 127: case ECP_224_BIT:
! 128: case ECP_256_BIT:
! 129: case ECP_384_BIT:
! 130: case ECP_521_BIT:
! 131: { /* we expect the public value to just be the concatenated x and y
! 132: * coordinates, so we tag the value as an uncompressed ECPoint */
! 133: chunk_t tag = chunk_from_chars(0x04);
! 134: chunk_t pubkey = chunk_cata("cc", tag, value);
! 135: CK_ECDH1_DERIVE_PARAMS params = {
! 136: CKD_NULL,
! 137: 0,
! 138: NULL,
! 139: pubkey.len,
! 140: pubkey.ptr,
! 141: };
! 142:
! 143: if (!lib->settings->get_bool(lib->settings,
! 144: "%s.ecp_x_coordinate_only", TRUE, lib->ns))
! 145: { /* we only get the x coordinate back */
! 146: return FALSE;
! 147: }
! 148: value = chunk_from_thing(params);
! 149: break;
! 150: }
! 151: default:
! 152: break;
! 153: }
! 154: return derive_secret(this, value);
! 155: }
! 156:
! 157: METHOD(diffie_hellman_t, get_my_public_value, bool,
! 158: private_pkcs11_dh_t *this, chunk_t *value)
! 159: {
! 160: *value = chunk_clone(this->pub_key);
! 161: return TRUE;
! 162: }
! 163:
! 164: METHOD(diffie_hellman_t, get_shared_secret, bool,
! 165: private_pkcs11_dh_t *this, chunk_t *secret)
! 166: {
! 167: if (!this->secret.ptr)
! 168: {
! 169: return FALSE;
! 170: }
! 171: *secret = chunk_clone(this->secret);
! 172: return TRUE;
! 173: }
! 174:
! 175: METHOD(diffie_hellman_t, get_dh_group, diffie_hellman_group_t,
! 176: private_pkcs11_dh_t *this)
! 177: {
! 178: return this->group;
! 179: }
! 180:
! 181: METHOD(diffie_hellman_t, destroy, void,
! 182: private_pkcs11_dh_t *this)
! 183: {
! 184: this->lib->f->C_CloseSession(this->session);
! 185: chunk_clear(&this->pub_key);
! 186: chunk_clear(&this->secret);
! 187: free(this);
! 188: }
! 189:
! 190: /**
! 191: * Generate a DH/ECDH key pair.
! 192: *
! 193: * If this succeeds, this->pri_key has a handle to the private key and
! 194: * this->pub_key stores the public key.
! 195: */
! 196: static bool generate_key_pair(private_pkcs11_dh_t *this, CK_ATTRIBUTE_PTR pub,
! 197: int pub_len, CK_ATTRIBUTE_PTR pri, int pri_len,
! 198: CK_ATTRIBUTE_TYPE attr)
! 199: {
! 200: CK_MECHANISM mech = {
! 201: this->mech_key,
! 202: NULL,
! 203: 0,
! 204: };
! 205: CK_OBJECT_HANDLE pub_key;
! 206: CK_RV rv;
! 207:
! 208: rv = this->lib->f->C_GenerateKeyPair(this->session, &mech, pub, pub_len,
! 209: pri, pri_len, &pub_key, &this->pri_key);
! 210: if (rv != CKR_OK)
! 211: {
! 212: DBG1(DBG_CFG, "C_GenerateKeyPair() error: %N", ck_rv_names, rv);
! 213: return FALSE;
! 214: }
! 215: if (!this->lib->get_ck_attribute(this->lib, this->session, pub_key,
! 216: attr, &this->pub_key))
! 217: {
! 218: chunk_free(&this->pub_key);
! 219: return FALSE;
! 220: }
! 221: return TRUE;
! 222: }
! 223:
! 224: /**
! 225: * Generate DH key pair.
! 226: */
! 227: static bool generate_key_pair_modp(private_pkcs11_dh_t *this, size_t exp_len,
! 228: chunk_t g, chunk_t p)
! 229: {
! 230: CK_BBOOL ck_true = CK_TRUE;
! 231: CK_ATTRIBUTE pub_attr[] = {
! 232: { CKA_DERIVE, &ck_true, sizeof(ck_true) },
! 233: { CKA_PRIME, p.ptr, p.len },
! 234: { CKA_BASE, g.ptr, g.len },
! 235: };
! 236: CK_ULONG bits = exp_len * 8;
! 237: CK_ATTRIBUTE pri_attr[] = {
! 238: { CKA_DERIVE, &ck_true, sizeof(ck_true) },
! 239: { CKA_VALUE_BITS, &bits, sizeof(bits) },
! 240: };
! 241: return generate_key_pair(this, pub_attr, countof(pub_attr), pri_attr,
! 242: countof(pri_attr), CKA_VALUE);
! 243: }
! 244:
! 245: /**
! 246: * Generate ECDH key pair.
! 247: */
! 248: static bool generate_key_pair_ecp(private_pkcs11_dh_t *this,
! 249: chunk_t ecparams)
! 250: {
! 251: CK_BBOOL ck_true = CK_TRUE;
! 252: CK_ATTRIBUTE pub_attr[] = {
! 253: { CKA_DERIVE, &ck_true, sizeof(ck_true) },
! 254: { CKA_EC_PARAMS, ecparams.ptr, ecparams.len },
! 255: };
! 256: CK_ATTRIBUTE pri_attr[] = {
! 257: { CKA_DERIVE, &ck_true, sizeof(ck_true) },
! 258: };
! 259: chunk_t pub_key;
! 260: if (!generate_key_pair(this, pub_attr, countof(pub_attr), pri_attr,
! 261: countof(pri_attr), CKA_EC_POINT))
! 262: {
! 263: return FALSE;
! 264: }
! 265: if (this->pub_key.len <= 0 || this->pub_key.ptr[0] != 0x04)
! 266: { /* we currently only support the point in uncompressed form which
! 267: * looks like this: 0x04 || x || y */
! 268: chunk_clear(&this->pub_key);
! 269: return FALSE;
! 270: }
! 271: pub_key = chunk_clone(chunk_skip(this->pub_key, 1));
! 272: chunk_clear(&this->pub_key);
! 273: this->pub_key = pub_key;
! 274: return TRUE;
! 275: }
! 276:
! 277: /**
! 278: * Find a token we can use for DH/ECDH algorithm
! 279: */
! 280: static pkcs11_library_t *find_token(private_pkcs11_dh_t *this,
! 281: CK_SESSION_HANDLE *session)
! 282: {
! 283: enumerator_t *tokens, *mechs;
! 284: pkcs11_manager_t *manager;
! 285: pkcs11_library_t *current, *found = NULL;
! 286: CK_MECHANISM_TYPE type;
! 287: CK_SLOT_ID slot;
! 288:
! 289: manager = lib->get(lib, "pkcs11-manager");
! 290: if (!manager)
! 291: {
! 292: return NULL;
! 293: }
! 294: tokens = manager->create_token_enumerator(manager);
! 295: while (tokens->enumerate(tokens, ¤t, &slot))
! 296: {
! 297: mechs = current->create_mechanism_enumerator(current, slot);
! 298: while (mechs->enumerate(mechs, &type, NULL))
! 299: { /* we assume we can generate key pairs if the derive mechanism
! 300: * is supported */
! 301: if (type == this->mech_derive)
! 302: {
! 303: if (current->f->C_OpenSession(slot, CKF_SERIAL_SESSION,
! 304: NULL, NULL, session) == CKR_OK)
! 305: {
! 306: found = current;
! 307: break;
! 308: }
! 309: }
! 310: }
! 311: mechs->destroy(mechs);
! 312: if (found)
! 313: {
! 314: break;
! 315: }
! 316: }
! 317: tokens->destroy(tokens);
! 318: return found;
! 319: }
! 320:
! 321: /**
! 322: * Generic internal constructor
! 323: */
! 324: static private_pkcs11_dh_t *create_generic(diffie_hellman_group_t group,
! 325: CK_MECHANISM_TYPE key,
! 326: CK_MECHANISM_TYPE derive)
! 327: {
! 328: private_pkcs11_dh_t *this;
! 329:
! 330: INIT(this,
! 331: .public = {
! 332: .dh = {
! 333: .get_shared_secret = _get_shared_secret,
! 334: .set_other_public_value = _set_other_public_value,
! 335: .get_my_public_value = _get_my_public_value,
! 336: .get_dh_group = _get_dh_group,
! 337: .destroy = _destroy,
! 338: },
! 339: },
! 340: .group = group,
! 341: .mech_key = key,
! 342: .mech_derive = derive,
! 343: );
! 344:
! 345: this->lib = find_token(this, &this->session);
! 346: if (!this->lib)
! 347: {
! 348: free(this);
! 349: return NULL;
! 350: }
! 351: return this;
! 352: }
! 353:
! 354: static pkcs11_dh_t *create_ecp(diffie_hellman_group_t group, chunk_t ecparam)
! 355: {
! 356: private_pkcs11_dh_t *this = create_generic(group, CKM_EC_KEY_PAIR_GEN,
! 357: CKM_ECDH1_DERIVE);
! 358:
! 359: if (this)
! 360: {
! 361: if (generate_key_pair_ecp(this, ecparam))
! 362: {
! 363: chunk_free(&ecparam);
! 364: return &this->public;
! 365: }
! 366: chunk_free(&ecparam);
! 367: free(this);
! 368: }
! 369: return NULL;
! 370: }
! 371:
! 372: /**
! 373: * Constructor for MODP DH
! 374: */
! 375: static pkcs11_dh_t *create_modp(diffie_hellman_group_t group, size_t exp_len,
! 376: chunk_t g, chunk_t p)
! 377: {
! 378: private_pkcs11_dh_t *this = create_generic(group, CKM_DH_PKCS_KEY_PAIR_GEN,
! 379: CKM_DH_PKCS_DERIVE);
! 380:
! 381: if (this)
! 382: {
! 383: if (generate_key_pair_modp(this, exp_len, g, p))
! 384: {
! 385: return &this->public;
! 386: }
! 387: free(this);
! 388: }
! 389: return NULL;
! 390: }
! 391:
! 392: /**
! 393: * Lookup the EC params for the given group.
! 394: */
! 395: static chunk_t ecparams_lookup(diffie_hellman_group_t group)
! 396: {
! 397: switch (group)
! 398: {
! 399: case ECP_192_BIT:
! 400: return asn1_build_known_oid(OID_PRIME192V1);
! 401: case ECP_224_BIT:
! 402: return asn1_build_known_oid(OID_SECT224R1);
! 403: case ECP_256_BIT:
! 404: return asn1_build_known_oid(OID_PRIME256V1);
! 405: case ECP_384_BIT:
! 406: return asn1_build_known_oid(OID_SECT384R1);
! 407: case ECP_521_BIT:
! 408: return asn1_build_known_oid(OID_SECT521R1);
! 409: default:
! 410: break;
! 411: }
! 412: return chunk_empty;
! 413: }
! 414:
! 415: /**
! 416: * Described in header.
! 417: */
! 418: pkcs11_dh_t *pkcs11_dh_create(diffie_hellman_group_t group, ...)
! 419: {
! 420: switch (group)
! 421: {
! 422: case MODP_CUSTOM:
! 423: {
! 424: chunk_t g, p;
! 425:
! 426: VA_ARGS_GET(group, g, p);
! 427: return create_modp(group, p.len, g, p);
! 428: }
! 429: case ECP_192_BIT:
! 430: case ECP_224_BIT:
! 431: case ECP_256_BIT:
! 432: case ECP_384_BIT:
! 433: case ECP_521_BIT:
! 434: {
! 435: chunk_t params = ecparams_lookup(group);
! 436: if (params.ptr)
! 437: {
! 438: return create_ecp(group, params);
! 439: }
! 440: break;
! 441: }
! 442: default:
! 443: {
! 444: diffie_hellman_params_t *params = diffie_hellman_get_params(group);
! 445: if (params)
! 446: {
! 447: return create_modp(group, params->exp_len, params->generator,
! 448: params->prime);
! 449: }
! 450: break;
! 451: }
! 452: }
! 453: return NULL;
! 454: }
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