1189251Ssam/* 2189251Ssam * EAP server/peer: EAP-SAKE shared routines 3189251Ssam * Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi> 4189251Ssam * 5252726Srpaulo * This software may be distributed under the terms of the BSD license. 6252726Srpaulo * See README for more details. 7189251Ssam */ 8189251Ssam 9189251Ssam#include "includes.h" 10189251Ssam 11189251Ssam#include "common.h" 12189251Ssam#include "wpabuf.h" 13214734Srpaulo#include "crypto/sha1.h" 14189251Ssam#include "eap_defs.h" 15189251Ssam#include "eap_sake_common.h" 16189251Ssam 17189251Ssam 18189251Ssamstatic int eap_sake_parse_add_attr(struct eap_sake_parse_attr *attr, 19189251Ssam const u8 *pos) 20189251Ssam{ 21189251Ssam size_t i; 22189251Ssam 23189251Ssam switch (pos[0]) { 24189251Ssam case EAP_SAKE_AT_RAND_S: 25189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_RAND_S"); 26189251Ssam if (pos[1] != 2 + EAP_SAKE_RAND_LEN) { 27189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_RAND_S with " 28189251Ssam "invalid length %d", pos[1]); 29189251Ssam return -1; 30189251Ssam } 31189251Ssam attr->rand_s = pos + 2; 32189251Ssam break; 33189251Ssam case EAP_SAKE_AT_RAND_P: 34189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_RAND_P"); 35189251Ssam if (pos[1] != 2 + EAP_SAKE_RAND_LEN) { 36189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_RAND_P with " 37189251Ssam "invalid length %d", pos[1]); 38189251Ssam return -1; 39189251Ssam } 40189251Ssam attr->rand_p = pos + 2; 41189251Ssam break; 42189251Ssam case EAP_SAKE_AT_MIC_S: 43189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_MIC_S"); 44189251Ssam if (pos[1] != 2 + EAP_SAKE_MIC_LEN) { 45189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_MIC_S with " 46189251Ssam "invalid length %d", pos[1]); 47189251Ssam return -1; 48189251Ssam } 49189251Ssam attr->mic_s = pos + 2; 50189251Ssam break; 51189251Ssam case EAP_SAKE_AT_MIC_P: 52189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_MIC_P"); 53189251Ssam if (pos[1] != 2 + EAP_SAKE_MIC_LEN) { 54189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_MIC_P with " 55189251Ssam "invalid length %d", pos[1]); 56189251Ssam return -1; 57189251Ssam } 58189251Ssam attr->mic_p = pos + 2; 59189251Ssam break; 60189251Ssam case EAP_SAKE_AT_SERVERID: 61189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_SERVERID"); 62189251Ssam attr->serverid = pos + 2; 63189251Ssam attr->serverid_len = pos[1] - 2; 64189251Ssam break; 65189251Ssam case EAP_SAKE_AT_PEERID: 66189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_PEERID"); 67189251Ssam attr->peerid = pos + 2; 68189251Ssam attr->peerid_len = pos[1] - 2; 69189251Ssam break; 70189251Ssam case EAP_SAKE_AT_SPI_S: 71189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_SPI_S"); 72189251Ssam attr->spi_s = pos + 2; 73189251Ssam attr->spi_s_len = pos[1] - 2; 74189251Ssam break; 75189251Ssam case EAP_SAKE_AT_SPI_P: 76189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_SPI_P"); 77189251Ssam attr->spi_p = pos + 2; 78189251Ssam attr->spi_p_len = pos[1] - 2; 79189251Ssam break; 80189251Ssam case EAP_SAKE_AT_ANY_ID_REQ: 81189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_ANY_ID_REQ"); 82189251Ssam if (pos[1] != 4) { 83189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Invalid AT_ANY_ID_REQ" 84189251Ssam " length %d", pos[1]); 85189251Ssam return -1; 86189251Ssam } 87189251Ssam attr->any_id_req = pos + 2; 88189251Ssam break; 89189251Ssam case EAP_SAKE_AT_PERM_ID_REQ: 90189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_PERM_ID_REQ"); 91189251Ssam if (pos[1] != 4) { 92189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Invalid " 93189251Ssam "AT_PERM_ID_REQ length %d", pos[1]); 94189251Ssam return -1; 95189251Ssam } 96189251Ssam attr->perm_id_req = pos + 2; 97189251Ssam break; 98189251Ssam case EAP_SAKE_AT_ENCR_DATA: 99189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_ENCR_DATA"); 100189251Ssam attr->encr_data = pos + 2; 101189251Ssam attr->encr_data_len = pos[1] - 2; 102189251Ssam break; 103189251Ssam case EAP_SAKE_AT_IV: 104189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_IV"); 105189251Ssam attr->iv = pos + 2; 106189251Ssam attr->iv_len = pos[1] - 2; 107189251Ssam break; 108189251Ssam case EAP_SAKE_AT_PADDING: 109189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_PADDING"); 110189251Ssam for (i = 2; i < pos[1]; i++) { 111189251Ssam if (pos[i]) { 112189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_PADDING " 113189251Ssam "with non-zero pad byte"); 114189251Ssam return -1; 115189251Ssam } 116189251Ssam } 117189251Ssam break; 118189251Ssam case EAP_SAKE_AT_NEXT_TMPID: 119189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_NEXT_TMPID"); 120189251Ssam attr->next_tmpid = pos + 2; 121189251Ssam attr->next_tmpid_len = pos[1] - 2; 122189251Ssam break; 123189251Ssam case EAP_SAKE_AT_MSK_LIFE: 124189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_IV"); 125189251Ssam if (pos[1] != 6) { 126189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Invalid " 127189251Ssam "AT_MSK_LIFE length %d", pos[1]); 128189251Ssam return -1; 129189251Ssam } 130189251Ssam attr->msk_life = pos + 2; 131189251Ssam break; 132189251Ssam default: 133189251Ssam if (pos[0] < 128) { 134189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Unknown non-skippable" 135189251Ssam " attribute %d", pos[0]); 136189251Ssam return -1; 137189251Ssam } 138189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Ignoring unknown skippable " 139189251Ssam "attribute %d", pos[0]); 140189251Ssam break; 141189251Ssam } 142189251Ssam 143189251Ssam if (attr->iv && !attr->encr_data) { 144189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_IV included without " 145189251Ssam "AT_ENCR_DATA"); 146189251Ssam return -1; 147189251Ssam } 148189251Ssam 149189251Ssam return 0; 150189251Ssam} 151189251Ssam 152189251Ssam 153189251Ssam/** 154189251Ssam * eap_sake_parse_attributes - Parse EAP-SAKE attributes 155189251Ssam * @buf: Packet payload (starting with the first attribute) 156189251Ssam * @len: Payload length 157189251Ssam * @attr: Structure to be filled with found attributes 158189251Ssam * Returns: 0 on success or -1 on failure 159189251Ssam */ 160189251Ssamint eap_sake_parse_attributes(const u8 *buf, size_t len, 161189251Ssam struct eap_sake_parse_attr *attr) 162189251Ssam{ 163189251Ssam const u8 *pos = buf, *end = buf + len; 164189251Ssam 165189251Ssam os_memset(attr, 0, sizeof(*attr)); 166189251Ssam while (pos < end) { 167189251Ssam if (end - pos < 2) { 168189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Too short attribute"); 169189251Ssam return -1; 170189251Ssam } 171189251Ssam 172189251Ssam if (pos[1] < 2) { 173189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Invalid attribute " 174189251Ssam "length (%d)", pos[1]); 175189251Ssam return -1; 176189251Ssam } 177189251Ssam 178189251Ssam if (pos + pos[1] > end) { 179189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Attribute underflow"); 180189251Ssam return -1; 181189251Ssam } 182189251Ssam 183189251Ssam if (eap_sake_parse_add_attr(attr, pos)) 184189251Ssam return -1; 185189251Ssam 186189251Ssam pos += pos[1]; 187189251Ssam } 188189251Ssam 189189251Ssam return 0; 190189251Ssam} 191189251Ssam 192189251Ssam 193189251Ssam/** 194189251Ssam * eap_sake_kdf - EAP-SAKE Key Derivation Function (KDF) 195189251Ssam * @key: Key for KDF 196189251Ssam * @key_len: Length of the key in bytes 197189251Ssam * @label: A unique label for each purpose of the KDF 198189251Ssam * @data: Extra data (start) to bind into the key 199189251Ssam * @data_len: Length of the data 200189251Ssam * @data2: Extra data (end) to bind into the key 201189251Ssam * @data2_len: Length of the data2 202189251Ssam * @buf: Buffer for the generated pseudo-random key 203189251Ssam * @buf_len: Number of bytes of key to generate 204189251Ssam * 205189251Ssam * This function is used to derive new, cryptographically separate keys from a 206189251Ssam * given key (e.g., SMS). This is identical to the PRF used in IEEE 802.11i. 207189251Ssam */ 208189251Ssamstatic void eap_sake_kdf(const u8 *key, size_t key_len, const char *label, 209189251Ssam const u8 *data, size_t data_len, 210189251Ssam const u8 *data2, size_t data2_len, 211189251Ssam u8 *buf, size_t buf_len) 212189251Ssam{ 213189251Ssam u8 counter = 0; 214189251Ssam size_t pos, plen; 215189251Ssam u8 hash[SHA1_MAC_LEN]; 216189251Ssam size_t label_len = os_strlen(label) + 1; 217189251Ssam const unsigned char *addr[4]; 218189251Ssam size_t len[4]; 219189251Ssam 220189251Ssam addr[0] = (u8 *) label; /* Label | Y */ 221189251Ssam len[0] = label_len; 222189251Ssam addr[1] = data; /* Msg[start] */ 223189251Ssam len[1] = data_len; 224189251Ssam addr[2] = data2; /* Msg[end] */ 225189251Ssam len[2] = data2_len; 226189251Ssam addr[3] = &counter; /* Length */ 227189251Ssam len[3] = 1; 228189251Ssam 229189251Ssam pos = 0; 230189251Ssam while (pos < buf_len) { 231189251Ssam plen = buf_len - pos; 232189251Ssam if (plen >= SHA1_MAC_LEN) { 233189251Ssam hmac_sha1_vector(key, key_len, 4, addr, len, 234189251Ssam &buf[pos]); 235189251Ssam pos += SHA1_MAC_LEN; 236189251Ssam } else { 237189251Ssam hmac_sha1_vector(key, key_len, 4, addr, len, 238189251Ssam hash); 239189251Ssam os_memcpy(&buf[pos], hash, plen); 240189251Ssam break; 241189251Ssam } 242189251Ssam counter++; 243189251Ssam } 244189251Ssam} 245189251Ssam 246189251Ssam 247189251Ssam/** 248189251Ssam * eap_sake_derive_keys - Derive EAP-SAKE keys 249189251Ssam * @root_secret_a: 16-byte Root-Secret-A 250189251Ssam * @root_secret_b: 16-byte Root-Secret-B 251189251Ssam * @rand_s: 16-byte RAND_S 252189251Ssam * @rand_p: 16-byte RAND_P 253189251Ssam * @tek: Buffer for Temporary EAK Keys (TEK-Auth[16] | TEK-Cipher[16]) 254189251Ssam * @msk: Buffer for 64-byte MSK 255189251Ssam * @emsk: Buffer for 64-byte EMSK 256189251Ssam * 257189251Ssam * This function derives EAP-SAKE keys as defined in RFC 4763, section 3.2.6. 258189251Ssam */ 259189251Ssamvoid eap_sake_derive_keys(const u8 *root_secret_a, const u8 *root_secret_b, 260189251Ssam const u8 *rand_s, const u8 *rand_p, u8 *tek, u8 *msk, 261189251Ssam u8 *emsk) 262189251Ssam{ 263189251Ssam u8 sms_a[EAP_SAKE_SMS_LEN]; 264189251Ssam u8 sms_b[EAP_SAKE_SMS_LEN]; 265189251Ssam u8 key_buf[EAP_MSK_LEN + EAP_EMSK_LEN]; 266189251Ssam 267189251Ssam wpa_printf(MSG_DEBUG, "EAP-SAKE: Deriving keys"); 268189251Ssam 269189251Ssam wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: Root-Secret-A", 270189251Ssam root_secret_a, EAP_SAKE_ROOT_SECRET_LEN); 271189251Ssam eap_sake_kdf(root_secret_a, EAP_SAKE_ROOT_SECRET_LEN, 272189251Ssam "SAKE Master Secret A", 273189251Ssam rand_p, EAP_SAKE_RAND_LEN, rand_s, EAP_SAKE_RAND_LEN, 274189251Ssam sms_a, EAP_SAKE_SMS_LEN); 275189251Ssam wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: SMS-A", sms_a, EAP_SAKE_SMS_LEN); 276189251Ssam eap_sake_kdf(sms_a, EAP_SAKE_SMS_LEN, "Transient EAP Key", 277189251Ssam rand_s, EAP_SAKE_RAND_LEN, rand_p, EAP_SAKE_RAND_LEN, 278189251Ssam tek, EAP_SAKE_TEK_LEN); 279189251Ssam wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: TEK-Auth", 280189251Ssam tek, EAP_SAKE_TEK_AUTH_LEN); 281189251Ssam wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: TEK-Cipher", 282189251Ssam tek + EAP_SAKE_TEK_AUTH_LEN, EAP_SAKE_TEK_CIPHER_LEN); 283189251Ssam 284189251Ssam wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: Root-Secret-B", 285189251Ssam root_secret_b, EAP_SAKE_ROOT_SECRET_LEN); 286189251Ssam eap_sake_kdf(root_secret_b, EAP_SAKE_ROOT_SECRET_LEN, 287189251Ssam "SAKE Master Secret B", 288189251Ssam rand_p, EAP_SAKE_RAND_LEN, rand_s, EAP_SAKE_RAND_LEN, 289189251Ssam sms_b, EAP_SAKE_SMS_LEN); 290189251Ssam wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: SMS-B", sms_b, EAP_SAKE_SMS_LEN); 291189251Ssam eap_sake_kdf(sms_b, EAP_SAKE_SMS_LEN, "Master Session Key", 292189251Ssam rand_s, EAP_SAKE_RAND_LEN, rand_p, EAP_SAKE_RAND_LEN, 293189251Ssam key_buf, sizeof(key_buf)); 294189251Ssam os_memcpy(msk, key_buf, EAP_MSK_LEN); 295189251Ssam os_memcpy(emsk, key_buf + EAP_MSK_LEN, EAP_EMSK_LEN); 296189251Ssam wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: MSK", msk, EAP_MSK_LEN); 297189251Ssam wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: EMSK", emsk, EAP_EMSK_LEN); 298189251Ssam} 299189251Ssam 300189251Ssam 301189251Ssam/** 302189251Ssam * eap_sake_compute_mic - Compute EAP-SAKE MIC for an EAP packet 303189251Ssam * @tek_auth: 16-byte TEK-Auth 304189251Ssam * @rand_s: 16-byte RAND_S 305189251Ssam * @rand_p: 16-byte RAND_P 306189251Ssam * @serverid: SERVERID 307189251Ssam * @serverid_len: SERVERID length 308189251Ssam * @peerid: PEERID 309189251Ssam * @peerid_len: PEERID length 310189251Ssam * @peer: MIC calculation for 0 = Server, 1 = Peer message 311189251Ssam * @eap: EAP packet 312189251Ssam * @eap_len: EAP packet length 313189251Ssam * @mic_pos: MIC position in the EAP packet (must be [eap .. eap + eap_len]) 314189251Ssam * @mic: Buffer for the computed 16-byte MIC 315189251Ssam */ 316189251Ssamint eap_sake_compute_mic(const u8 *tek_auth, 317189251Ssam const u8 *rand_s, const u8 *rand_p, 318189251Ssam const u8 *serverid, size_t serverid_len, 319189251Ssam const u8 *peerid, size_t peerid_len, 320189251Ssam int peer, const u8 *eap, size_t eap_len, 321189251Ssam const u8 *mic_pos, u8 *mic) 322189251Ssam{ 323189251Ssam u8 _rand[2 * EAP_SAKE_RAND_LEN]; 324189251Ssam u8 *tmp, *pos; 325189251Ssam size_t tmplen; 326189251Ssam 327189251Ssam tmplen = serverid_len + 1 + peerid_len + 1 + eap_len; 328189251Ssam tmp = os_malloc(tmplen); 329189251Ssam if (tmp == NULL) 330189251Ssam return -1; 331189251Ssam pos = tmp; 332189251Ssam if (peer) { 333189251Ssam if (peerid) { 334189251Ssam os_memcpy(pos, peerid, peerid_len); 335189251Ssam pos += peerid_len; 336189251Ssam } 337189251Ssam *pos++ = 0x00; 338189251Ssam if (serverid) { 339189251Ssam os_memcpy(pos, serverid, serverid_len); 340189251Ssam pos += serverid_len; 341189251Ssam } 342189251Ssam *pos++ = 0x00; 343189251Ssam 344189251Ssam os_memcpy(_rand, rand_s, EAP_SAKE_RAND_LEN); 345189251Ssam os_memcpy(_rand + EAP_SAKE_RAND_LEN, rand_p, 346189251Ssam EAP_SAKE_RAND_LEN); 347189251Ssam } else { 348189251Ssam if (serverid) { 349189251Ssam os_memcpy(pos, serverid, serverid_len); 350189251Ssam pos += serverid_len; 351189251Ssam } 352189251Ssam *pos++ = 0x00; 353189251Ssam if (peerid) { 354189251Ssam os_memcpy(pos, peerid, peerid_len); 355189251Ssam pos += peerid_len; 356189251Ssam } 357189251Ssam *pos++ = 0x00; 358189251Ssam 359189251Ssam os_memcpy(_rand, rand_p, EAP_SAKE_RAND_LEN); 360189251Ssam os_memcpy(_rand + EAP_SAKE_RAND_LEN, rand_s, 361189251Ssam EAP_SAKE_RAND_LEN); 362189251Ssam } 363189251Ssam 364189251Ssam os_memcpy(pos, eap, eap_len); 365189251Ssam os_memset(pos + (mic_pos - eap), 0, EAP_SAKE_MIC_LEN); 366189251Ssam 367189251Ssam eap_sake_kdf(tek_auth, EAP_SAKE_TEK_AUTH_LEN, 368189251Ssam peer ? "Peer MIC" : "Server MIC", 369189251Ssam _rand, 2 * EAP_SAKE_RAND_LEN, tmp, tmplen, 370189251Ssam mic, EAP_SAKE_MIC_LEN); 371189251Ssam 372189251Ssam os_free(tmp); 373189251Ssam 374189251Ssam return 0; 375189251Ssam} 376189251Ssam 377189251Ssam 378189251Ssamvoid eap_sake_add_attr(struct wpabuf *buf, u8 type, const u8 *data, 379189251Ssam size_t len) 380189251Ssam{ 381189251Ssam wpabuf_put_u8(buf, type); 382189251Ssam wpabuf_put_u8(buf, 2 + len); /* Length; including attr header */ 383189251Ssam if (data) 384189251Ssam wpabuf_put_data(buf, data, len); 385189251Ssam else 386189251Ssam os_memset(wpabuf_put(buf, len), 0, len); 387189251Ssam} 388