X-Git-Url: http://www.project-moonshot.org/gitweb/?a=blobdiff_plain;f=libeap%2Fsrc%2Ftls%2Fpkcs5.c;fp=libeap%2Fsrc%2Ftls%2Fpkcs5.c;h=a2ad83b8a898d1dd2b4750c3c8a843e3f372a299;hb=88e34eecb5769da6526361b35df00fdbe823eac5;hp=0000000000000000000000000000000000000000;hpb=2394142e4bf89e0a9e2a0091ac16bd6442e3d4c7;p=mech_eap.git diff --git a/libeap/src/tls/pkcs5.c b/libeap/src/tls/pkcs5.c new file mode 100644 index 0000000..a2ad83b --- /dev/null +++ b/libeap/src/tls/pkcs5.c @@ -0,0 +1,650 @@ +/* + * PKCS #5 (Password-based Encryption) + * Copyright (c) 2009-2015, Jouni Malinen + * + * This software may be distributed under the terms of the BSD license. + * See README for more details. + */ + +#include "includes.h" + +#include "common.h" +#include "crypto/crypto.h" +#include "crypto/md5.h" +#include "crypto/sha1.h" +#include "asn1.h" +#include "pkcs5.h" + + +struct pkcs5_params { + enum pkcs5_alg { + PKCS5_ALG_UNKNOWN, + PKCS5_ALG_MD5_DES_CBC, + PKCS5_ALG_PBES2, + PKCS5_ALG_SHA1_3DES_CBC, + } alg; + u8 salt[64]; + size_t salt_len; + unsigned int iter_count; + enum pbes2_enc_alg { + PBES2_ENC_ALG_UNKNOWN, + PBES2_ENC_ALG_DES_EDE3_CBC, + } enc_alg; + u8 iv[8]; + size_t iv_len; +}; + + +static int oid_is_rsadsi(struct asn1_oid *oid) +{ + return oid->len >= 4 && + oid->oid[0] == 1 /* iso */ && + oid->oid[1] == 2 /* member-body */ && + oid->oid[2] == 840 /* us */ && + oid->oid[3] == 113549 /* rsadsi */; +} + + +static int pkcs5_is_oid(struct asn1_oid *oid, unsigned long alg) +{ + return oid->len == 7 && + oid_is_rsadsi(oid) && + oid->oid[4] == 1 /* pkcs */ && + oid->oid[5] == 5 /* pkcs-5 */ && + oid->oid[6] == alg; +} + + +static int enc_alg_is_oid(struct asn1_oid *oid, unsigned long alg) +{ + return oid->len == 6 && + oid_is_rsadsi(oid) && + oid->oid[4] == 3 /* encryptionAlgorithm */ && + oid->oid[5] == alg; +} + + +static int pkcs12_is_pbe_oid(struct asn1_oid *oid, unsigned long alg) +{ + return oid->len == 8 && + oid_is_rsadsi(oid) && + oid->oid[4] == 1 /* pkcs */ && + oid->oid[5] == 12 /* pkcs-12 */ && + oid->oid[6] == 1 /* pkcs-12PbeIds */ && + oid->oid[7] == alg; +} + + +static enum pkcs5_alg pkcs5_get_alg(struct asn1_oid *oid) +{ + if (pkcs5_is_oid(oid, 3)) /* pbeWithMD5AndDES-CBC (PBES1) */ + return PKCS5_ALG_MD5_DES_CBC; + if (pkcs12_is_pbe_oid(oid, 3)) /* pbeWithSHAAnd3-KeyTripleDES-CBC */ + return PKCS5_ALG_SHA1_3DES_CBC; + if (pkcs5_is_oid(oid, 13)) /* id-PBES2 (PBES2) */ + return PKCS5_ALG_PBES2; + return PKCS5_ALG_UNKNOWN; +} + + +static int pkcs5_get_params_pbes2(struct pkcs5_params *params, const u8 *pos, + const u8 *enc_alg_end) +{ + struct asn1_hdr hdr; + const u8 *end, *kdf_end; + struct asn1_oid oid; + char obuf[80]; + + /* + * RFC 2898, Ch. A.4 + * + * PBES2-params ::= SEQUENCE { + * keyDerivationFunc AlgorithmIdentifier {{PBES2-KDFs}}, + * encryptionScheme AlgorithmIdentifier {{PBES2-Encs}} } + * + * PBES2-KDFs ALGORITHM-IDENTIFIER ::= + * { {PBKDF2-params IDENTIFIED BY id-PBKDF2}, ... } + */ + + if (asn1_get_next(pos, enc_alg_end - pos, &hdr) < 0 || + hdr.class != ASN1_CLASS_UNIVERSAL || + hdr.tag != ASN1_TAG_SEQUENCE) { + wpa_printf(MSG_DEBUG, + "PKCS #5: Expected SEQUENCE (PBES2-params) - found class %d tag 0x%x", + hdr.class, hdr.tag); + return -1; + } + pos = hdr.payload; + end = hdr.payload + hdr.length; + + if (asn1_get_next(pos, end - pos, &hdr) < 0 || + hdr.class != ASN1_CLASS_UNIVERSAL || + hdr.tag != ASN1_TAG_SEQUENCE) { + wpa_printf(MSG_DEBUG, + "PKCS #5: Expected SEQUENCE (keyDerivationFunc) - found class %d tag 0x%x", + hdr.class, hdr.tag); + return -1; + } + + pos = hdr.payload; + kdf_end = end = hdr.payload + hdr.length; + + if (asn1_get_oid(pos, end - pos, &oid, &pos)) { + wpa_printf(MSG_DEBUG, + "PKCS #5: Failed to parse OID (keyDerivationFunc algorithm)"); + return -1; + } + + asn1_oid_to_str(&oid, obuf, sizeof(obuf)); + wpa_printf(MSG_DEBUG, "PKCS #5: PBES2 keyDerivationFunc algorithm %s", + obuf); + if (!pkcs5_is_oid(&oid, 12)) /* id-PBKDF2 */ { + wpa_printf(MSG_DEBUG, + "PKCS #5: Unsupported PBES2 keyDerivationFunc algorithm %s", + obuf); + return -1; + } + + /* + * RFC 2898, C. + * + * PBKDF2-params ::= SEQUENCE { + * salt CHOICE { + * specified OCTET STRING, + * otherSource AlgorithmIdentifier {{PBKDF2-SaltSources}} + * }, + * iterationCount INTEGER (1..MAX), + * keyLength INTEGER (1..MAX) OPTIONAL, + * prf AlgorithmIdentifier {{PBKDF2-PRFs}} DEFAULT + * algid-hmacWithSHA1 + * } + */ + + if (asn1_get_next(pos, end - pos, &hdr) < 0 || + hdr.class != ASN1_CLASS_UNIVERSAL || + hdr.tag != ASN1_TAG_SEQUENCE) { + wpa_printf(MSG_DEBUG, + "PKCS #5: Expected SEQUENCE (PBKDF2-params) - found class %d tag 0x%x", + hdr.class, hdr.tag); + return -1; + } + + pos = hdr.payload; + end = hdr.payload + hdr.length; + + /* For now, only support the salt CHOICE specified (OCTET STRING) */ + if (asn1_get_next(pos, end - pos, &hdr) < 0 || + hdr.class != ASN1_CLASS_UNIVERSAL || + hdr.tag != ASN1_TAG_OCTETSTRING || + hdr.length > sizeof(params->salt)) { + wpa_printf(MSG_DEBUG, + "PKCS #5: Expected OCTET STRING (salt.specified) - found class %d tag 0x%x size %d", + hdr.class, hdr.tag, hdr.length); + return -1; + } + pos = hdr.payload + hdr.length; + os_memcpy(params->salt, hdr.payload, hdr.length); + params->salt_len = hdr.length; + wpa_hexdump(MSG_DEBUG, "PKCS #5: salt", params->salt, params->salt_len); + + /* iterationCount INTEGER */ + if (asn1_get_next(pos, end - pos, &hdr) < 0 || + hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER) { + wpa_printf(MSG_DEBUG, + "PKCS #5: Expected INTEGER - found class %d tag 0x%x", + hdr.class, hdr.tag); + return -1; + } + if (hdr.length == 1) { + params->iter_count = *hdr.payload; + } else if (hdr.length == 2) { + params->iter_count = WPA_GET_BE16(hdr.payload); + } else if (hdr.length == 4) { + params->iter_count = WPA_GET_BE32(hdr.payload); + } else { + wpa_hexdump(MSG_DEBUG, + "PKCS #5: Unsupported INTEGER value (iterationCount)", + hdr.payload, hdr.length); + return -1; + } + wpa_printf(MSG_DEBUG, "PKCS #5: iterationCount=0x%x", + params->iter_count); + if (params->iter_count == 0 || params->iter_count > 0xffff) { + wpa_printf(MSG_INFO, "PKCS #5: Unsupported iterationCount=0x%x", + params->iter_count); + return -1; + } + + /* For now, ignore optional keyLength and prf */ + + pos = kdf_end; + + /* encryptionScheme AlgorithmIdentifier {{PBES2-Encs}} */ + + if (asn1_get_next(pos, enc_alg_end - pos, &hdr) < 0 || + hdr.class != ASN1_CLASS_UNIVERSAL || + hdr.tag != ASN1_TAG_SEQUENCE) { + wpa_printf(MSG_DEBUG, + "PKCS #5: Expected SEQUENCE (encryptionScheme) - found class %d tag 0x%x", + hdr.class, hdr.tag); + return -1; + } + + pos = hdr.payload; + end = hdr.payload + hdr.length; + + if (asn1_get_oid(pos, end - pos, &oid, &pos)) { + wpa_printf(MSG_DEBUG, + "PKCS #5: Failed to parse OID (encryptionScheme algorithm)"); + return -1; + } + + asn1_oid_to_str(&oid, obuf, sizeof(obuf)); + wpa_printf(MSG_DEBUG, "PKCS #5: PBES2 encryptionScheme algorithm %s", + obuf); + if (enc_alg_is_oid(&oid, 7)) { + params->enc_alg = PBES2_ENC_ALG_DES_EDE3_CBC; + } else { + wpa_printf(MSG_DEBUG, + "PKCS #5: Unsupported PBES2 encryptionScheme algorithm %s", + obuf); + return -1; + } + + /* + * RFC 2898, B.2.2: + * The parameters field associated with this OID in an + * AlgorithmIdentifier shall have type OCTET STRING (SIZE(8)), + * specifying the initialization vector for CBC mode. + */ + if (asn1_get_next(pos, end - pos, &hdr) < 0 || + hdr.class != ASN1_CLASS_UNIVERSAL || + hdr.tag != ASN1_TAG_OCTETSTRING || + hdr.length != 8) { + wpa_printf(MSG_DEBUG, + "PKCS #5: Expected OCTET STRING (SIZE(8)) (IV) - found class %d tag 0x%x size %d", + hdr.class, hdr.tag, hdr.length); + return -1; + } + os_memcpy(params->iv, hdr.payload, hdr.length); + params->iv_len = hdr.length; + wpa_hexdump(MSG_DEBUG, "PKCS #5: IV", params->iv, params->iv_len); + + return 0; +} + + +static int pkcs5_get_params(const u8 *enc_alg, size_t enc_alg_len, + struct pkcs5_params *params) +{ + struct asn1_hdr hdr; + const u8 *enc_alg_end, *pos, *end; + struct asn1_oid oid; + char obuf[80]; + + /* AlgorithmIdentifier */ + + enc_alg_end = enc_alg + enc_alg_len; + + os_memset(params, 0, sizeof(*params)); + + if (asn1_get_oid(enc_alg, enc_alg_end - enc_alg, &oid, &pos)) { + wpa_printf(MSG_DEBUG, "PKCS #5: Failed to parse OID " + "(algorithm)"); + return -1; + } + + asn1_oid_to_str(&oid, obuf, sizeof(obuf)); + wpa_printf(MSG_DEBUG, "PKCS #5: encryption algorithm %s", obuf); + params->alg = pkcs5_get_alg(&oid); + if (params->alg == PKCS5_ALG_UNKNOWN) { + wpa_printf(MSG_INFO, "PKCS #5: unsupported encryption " + "algorithm %s", obuf); + return -1; + } + + if (params->alg == PKCS5_ALG_PBES2) + return pkcs5_get_params_pbes2(params, pos, enc_alg_end); + + /* PBES1 */ + + /* + * PKCS#5, Section 8 + * PBEParameter ::= SEQUENCE { + * salt OCTET STRING SIZE(8), + * iterationCount INTEGER } + * + * Note: The same implementation can be used to parse the PKCS #12 + * version described in RFC 7292, C: + * pkcs-12PbeParams ::= SEQUENCE { + * salt OCTET STRING, + * iterations INTEGER + * } + */ + + if (asn1_get_next(pos, enc_alg_end - pos, &hdr) < 0 || + hdr.class != ASN1_CLASS_UNIVERSAL || + hdr.tag != ASN1_TAG_SEQUENCE) { + wpa_printf(MSG_DEBUG, "PKCS #5: Expected SEQUENCE " + "(PBEParameter) - found class %d tag 0x%x", + hdr.class, hdr.tag); + return -1; + } + pos = hdr.payload; + end = hdr.payload + hdr.length; + + /* salt OCTET STRING SIZE(8) (PKCS #5) or OCTET STRING (PKCS #12) */ + if (asn1_get_next(pos, end - pos, &hdr) < 0 || + hdr.class != ASN1_CLASS_UNIVERSAL || + hdr.tag != ASN1_TAG_OCTETSTRING || + hdr.length > sizeof(params->salt)) { + wpa_printf(MSG_DEBUG, "PKCS #5: Expected OCTETSTRING SIZE(8) " + "(salt) - found class %d tag 0x%x size %d", + hdr.class, hdr.tag, hdr.length); + return -1; + } + pos = hdr.payload + hdr.length; + os_memcpy(params->salt, hdr.payload, hdr.length); + params->salt_len = hdr.length; + wpa_hexdump(MSG_DEBUG, "PKCS #5: salt", + params->salt, params->salt_len); + + /* iterationCount INTEGER */ + if (asn1_get_next(pos, end - pos, &hdr) < 0 || + hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER) { + wpa_printf(MSG_DEBUG, "PKCS #5: Expected INTEGER - found " + "class %d tag 0x%x", hdr.class, hdr.tag); + return -1; + } + if (hdr.length == 1) + params->iter_count = *hdr.payload; + else if (hdr.length == 2) + params->iter_count = WPA_GET_BE16(hdr.payload); + else if (hdr.length == 4) + params->iter_count = WPA_GET_BE32(hdr.payload); + else { + wpa_hexdump(MSG_DEBUG, "PKCS #5: Unsupported INTEGER value " + " (iterationCount)", + hdr.payload, hdr.length); + return -1; + } + wpa_printf(MSG_DEBUG, "PKCS #5: iterationCount=0x%x", + params->iter_count); + if (params->iter_count == 0 || params->iter_count > 0xffff) { + wpa_printf(MSG_INFO, "PKCS #5: Unsupported " + "iterationCount=0x%x", params->iter_count); + return -1; + } + + return 0; +} + + +static struct crypto_cipher * +pkcs5_crypto_init_pbes2(struct pkcs5_params *params, const char *passwd) +{ + u8 key[24]; + + if (params->enc_alg != PBES2_ENC_ALG_DES_EDE3_CBC || + params->iv_len != 8) + return NULL; + + wpa_hexdump_ascii_key(MSG_DEBUG, "PKCS #5: PBES2 password for PBKDF2", + passwd, os_strlen(passwd)); + wpa_hexdump(MSG_DEBUG, "PKCS #5: PBES2 salt for PBKDF2", + params->salt, params->salt_len); + wpa_printf(MSG_DEBUG, "PKCS #5: PBES2 PBKDF2 iterations: %u", + params->iter_count); + if (pbkdf2_sha1(passwd, params->salt, params->salt_len, + params->iter_count, key, sizeof(key)) < 0) + return NULL; + wpa_hexdump_key(MSG_DEBUG, "PKCS #5: DES EDE3 key", key, sizeof(key)); + wpa_hexdump(MSG_DEBUG, "PKCS #5: DES IV", params->iv, params->iv_len); + + return crypto_cipher_init(CRYPTO_CIPHER_ALG_3DES, params->iv, + key, sizeof(key)); +} + + +static void add_byte_array_mod(u8 *a, const u8 *b, size_t len) +{ + size_t i; + unsigned int carry = 0; + + for (i = len - 1; i < len; i--) { + carry = carry + a[i] + b[i]; + a[i] = carry & 0xff; + carry >>= 8; + } +} + + +static int pkcs12_key_gen(const u8 *pw, size_t pw_len, const u8 *salt, + size_t salt_len, u8 id, unsigned int iter, + size_t out_len, u8 *out) +{ + unsigned int u, v, S_len, P_len, i; + u8 *D = NULL, *I = NULL, *B = NULL, *pos; + int res = -1; + + /* RFC 7292, B.2 */ + u = SHA1_MAC_LEN; + v = 64; + + /* D = copies of ID */ + D = os_malloc(v); + if (!D) + goto done; + os_memset(D, id, v); + + /* S = copies of salt; P = copies of password, I = S || P */ + S_len = v * ((salt_len + v - 1) / v); + P_len = v * ((pw_len + v - 1) / v); + I = os_malloc(S_len + P_len); + if (!I) + goto done; + pos = I; + if (salt_len) { + for (i = 0; i < S_len; i++) + *pos++ = salt[i % salt_len]; + } + if (pw_len) { + for (i = 0; i < P_len; i++) + *pos++ = pw[i % pw_len]; + } + + B = os_malloc(v); + if (!B) + goto done; + + for (;;) { + u8 hash[SHA1_MAC_LEN]; + const u8 *addr[2]; + size_t len[2]; + + addr[0] = D; + len[0] = v; + addr[1] = I; + len[1] = S_len + P_len; + if (sha1_vector(2, addr, len, hash) < 0) + goto done; + + addr[0] = hash; + len[0] = SHA1_MAC_LEN; + for (i = 1; i < iter; i++) { + if (sha1_vector(1, addr, len, hash) < 0) + goto done; + } + + if (out_len <= u) { + os_memcpy(out, hash, out_len); + res = 0; + goto done; + } + + os_memcpy(out, hash, u); + out += u; + out_len -= u; + + /* I_j = (I_j + B + 1) mod 2^(v*8) */ + /* B = copies of Ai (final hash value) */ + for (i = 0; i < v; i++) + B[i] = hash[i % u]; + inc_byte_array(B, v); + for (i = 0; i < S_len + P_len; i += v) + add_byte_array_mod(&I[i], B, v); + } + +done: + os_free(B); + os_free(I); + os_free(D); + return res; +} + + +#define PKCS12_ID_ENC 1 +#define PKCS12_ID_IV 2 +#define PKCS12_ID_MAC 3 + +static struct crypto_cipher * +pkcs12_crypto_init_sha1(struct pkcs5_params *params, const char *passwd) +{ + unsigned int i; + u8 *pw; + size_t pw_len; + u8 key[24]; + u8 iv[8]; + + if (params->alg != PKCS5_ALG_SHA1_3DES_CBC) + return NULL; + + pw_len = passwd ? os_strlen(passwd) : 0; + pw = os_malloc(2 * (pw_len + 1)); + if (!pw) + return NULL; + if (pw_len) { + for (i = 0; i <= pw_len; i++) + WPA_PUT_BE16(&pw[2 * i], passwd[i]); + pw_len = 2 * (pw_len + 1); + } + + if (pkcs12_key_gen(pw, pw_len, params->salt, params->salt_len, + PKCS12_ID_ENC, params->iter_count, + sizeof(key), key) < 0 || + pkcs12_key_gen(pw, pw_len, params->salt, params->salt_len, + PKCS12_ID_IV, params->iter_count, + sizeof(iv), iv) < 0) { + os_free(pw); + return NULL; + } + + os_free(pw); + + wpa_hexdump_key(MSG_DEBUG, "PKCS #12: DES key", key, sizeof(key)); + wpa_hexdump_key(MSG_DEBUG, "PKCS #12: DES IV", iv, sizeof(iv)); + + return crypto_cipher_init(CRYPTO_CIPHER_ALG_3DES, iv, key, sizeof(key)); +} + + +static struct crypto_cipher * pkcs5_crypto_init(struct pkcs5_params *params, + const char *passwd) +{ + unsigned int i; + u8 hash[MD5_MAC_LEN]; + const u8 *addr[2]; + size_t len[2]; + + if (params->alg == PKCS5_ALG_PBES2) + return pkcs5_crypto_init_pbes2(params, passwd); + + if (params->alg == PKCS5_ALG_SHA1_3DES_CBC) + return pkcs12_crypto_init_sha1(params, passwd); + + if (params->alg != PKCS5_ALG_MD5_DES_CBC) + return NULL; + + addr[0] = (const u8 *) passwd; + len[0] = os_strlen(passwd); + addr[1] = params->salt; + len[1] = params->salt_len; + if (md5_vector(2, addr, len, hash) < 0) + return NULL; + addr[0] = hash; + len[0] = MD5_MAC_LEN; + for (i = 1; i < params->iter_count; i++) { + if (md5_vector(1, addr, len, hash) < 0) + return NULL; + } + /* TODO: DES key parity bits(?) */ + wpa_hexdump_key(MSG_DEBUG, "PKCS #5: DES key", hash, 8); + wpa_hexdump_key(MSG_DEBUG, "PKCS #5: DES IV", hash + 8, 8); + + return crypto_cipher_init(CRYPTO_CIPHER_ALG_DES, hash + 8, hash, 8); +} + + +u8 * pkcs5_decrypt(const u8 *enc_alg, size_t enc_alg_len, + const u8 *enc_data, size_t enc_data_len, + const char *passwd, size_t *data_len) +{ + struct crypto_cipher *ctx; + u8 *eb, pad; + struct pkcs5_params params; + unsigned int i; + + if (pkcs5_get_params(enc_alg, enc_alg_len, ¶ms) < 0) { + wpa_printf(MSG_DEBUG, "PKCS #5: Unsupported parameters"); + return NULL; + } + + ctx = pkcs5_crypto_init(¶ms, passwd); + if (ctx == NULL) { + wpa_printf(MSG_DEBUG, "PKCS #5: Failed to initialize crypto"); + return NULL; + } + + /* PKCS #5, Section 7 - Decryption process */ + if (enc_data_len < 16 || enc_data_len % 8) { + wpa_printf(MSG_INFO, "PKCS #5: invalid length of ciphertext " + "%d", (int) enc_data_len); + crypto_cipher_deinit(ctx); + return NULL; + } + + eb = os_malloc(enc_data_len); + if (eb == NULL) { + crypto_cipher_deinit(ctx); + return NULL; + } + + if (crypto_cipher_decrypt(ctx, enc_data, eb, enc_data_len) < 0) { + wpa_printf(MSG_DEBUG, "PKCS #5: Failed to decrypt EB"); + crypto_cipher_deinit(ctx); + os_free(eb); + return NULL; + } + crypto_cipher_deinit(ctx); + + pad = eb[enc_data_len - 1]; + if (pad > 8) { + wpa_printf(MSG_INFO, "PKCS #5: Invalid PS octet 0x%x", pad); + os_free(eb); + return NULL; + } + for (i = enc_data_len - pad; i < enc_data_len; i++) { + if (eb[i] != pad) { + wpa_hexdump(MSG_INFO, "PKCS #5: Invalid PS", + eb + enc_data_len - pad, pad); + os_free(eb); + return NULL; + } + } + + wpa_hexdump_key(MSG_MSGDUMP, "PKCS #5: message M (encrypted key)", + eb, enc_data_len - pad); + + *data_len = enc_data_len - pad; + return eb; +}