Merge remote-tracking branch 'origin/debian' into debian
[mech_eap.git] / libeap / src / tls / pkcs5.c
diff --git a/libeap/src/tls/pkcs5.c b/libeap/src/tls/pkcs5.c
new file mode 100644 (file)
index 0000000..a2ad83b
--- /dev/null
@@ -0,0 +1,650 @@
+/*
+ * PKCS #5 (Password-based Encryption)
+ * Copyright (c) 2009-2015, Jouni Malinen <j@w1.fi>
+ *
+ * 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, &params) < 0) {
+               wpa_printf(MSG_DEBUG, "PKCS #5: Unsupported parameters");
+               return NULL;
+       }
+
+       ctx = pkcs5_crypto_init(&params, 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;
+}