rlm_pap.c

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/*
 *   This program is is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or (at
 *   your option) any later version.
 *
 *   This program 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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: 50818f979867e98520f89503d6dc9a7290019d21 $
 * @file rlm_pap.c
 * @brief Hashes plaintext passwords to compare against a prehashed reference.
 *
 * @copyright 2001-2012 The FreeRADIUS server project.
 * @copyright 2012 Matthew Newton (matthew@newtoncomputing.co.uk)
 * @copyright 2001 Kostas Kalevras (kkalev@noc.ntua.gr)
 */
RCSID("$Id: 50818f979867e98520f89503d6dc9a7290019d21 $")
USES_APPLE_DEPRECATED_API
 
#include <freeradius-devel/server/base.h>
#include <freeradius-devel/server/module_rlm.h>
#include <freeradius-devel/server/password.h>
#include <freeradius-devel/tls/base.h>
#include <freeradius-devel/tls/log.h>
 
#include <freeradius-devel/util/base64.h>
#include <freeradius-devel/util/debug.h>
#include <freeradius-devel/util/base16.h>
#include <freeradius-devel/util/md5.h>
#include <freeradius-devel/util/sha1.h>
 
#include <freeradius-devel/unlang/call_env.h>
 
#include <freeradius-devel/protocol/freeradius/freeradius.internal.password.h>
 
#include <ctype.h>
 
#ifdef HAVE_CRYPT_H
#  include <crypt.h>
#endif
#include <unistd.h>     /* Contains crypt function declarations */
 
#ifdef HAVE_OPENSSL_EVP_H
#  include <freeradius-devel/tls/openssl_user_macros.h>
#  include <openssl/evp.h>
#endif
 
/*
 *      We don't have threadsafe crypt, so we have to wrap
 *      calls in a mutex
 */
#ifndef HAVE_CRYPT_R
#  include <pthread.h>
static pthread_mutex_t fr_crypt_mutex = PTHREAD_MUTEX_INITIALIZER;
#endif
 
/*
 *      Define a structure for our module configuration.
 *
 *      These variables do not need to be in a structure, but it's
 *      a lot cleaner to do so, and a pointer to the structure can
 *      be used as the instance handle.
 */
typedef struct {
        fr_dict_enum_value_t    *auth_type;
        bool                    normify;
} rlm_pap_t;
 
typedef unlang_action_t (*pap_auth_func_t)(rlm_rcode_t *p_result, rlm_pap_t const *inst, request_t *request, fr_pair_t const *, fr_value_box_t const *);
 
static const conf_parser_t module_config[] = {
        { FR_CONF_OFFSET("normalise", rlm_pap_t, normify), .dflt = "yes" },
        CONF_PARSER_TERMINATOR
};
 
typedef struct {
        fr_value_box_t  password;
        tmpl_t          *password_tmpl;
} pap_call_env_t;
 
static const call_env_method_t pap_method_env = {
        .inst_size = sizeof(pap_call_env_t),
        .inst_type = "pap_call_env_t",
        .env = (call_env_parser_t[]) {
                { FR_CALL_ENV_PARSE_OFFSET("password_attribute", FR_TYPE_STRING,
                                          CALL_ENV_FLAG_ATTRIBUTE | CALL_ENV_FLAG_REQUIRED | CALL_ENV_FLAG_NULLABLE | CALL_ENV_FLAG_CONCAT,
                                          pap_call_env_t, password, password_tmpl), .pair.dflt = "&User-Password", .pair.dflt_quote = T_BARE_WORD },
                CALL_ENV_TERMINATOR
        }
};
 
static fr_dict_t const *dict_freeradius;
 
static fr_dict_autoload_t rlm_pap_dict[] = {
        { .out = &dict_freeradius, .proto = "freeradius" },
        { NULL }
};
 
static fr_dict_attr_t const *attr_auth_type;
static fr_dict_attr_t const *attr_root;
 
static fr_dict_attr_autoload_t rlm_pap_dict_attr[] = {
        { .out = &attr_auth_type, .name = "Auth-Type", .type = FR_TYPE_UINT32, .dict = &dict_freeradius },
        { .out = &attr_root, .name = "Password", .type = FR_TYPE_TLV, .dict = &dict_freeradius },
 
        { NULL }
};
 
#ifdef HAVE_OPENSSL_EVP_H
static fr_table_num_sorted_t const pbkdf2_crypt_names[] = {
        { L("HMACSHA1"),        FR_SSHA1 },
        { L("HMACSHA2+224"),    FR_SSHA2_224 },
        { L("HMACSHA2+256"),    FR_SSHA2_256 },
        { L("HMACSHA2+384"),    FR_SSHA2_384 },
        { L("HMACSHA2+512"),    FR_SSHA2_512 },
        { L("HMACSHA3+224"),    FR_SSHA3_224 },
        { L("HMACSHA3+256"),    FR_SSHA3_256 },
        { L("HMACSHA3+384"),    FR_SSHA3_384 },
        { L("HMACSHA3+512"),    FR_SSHA3_512 },
};
static size_t pbkdf2_crypt_names_len = NUM_ELEMENTS(pbkdf2_crypt_names);
 
static fr_table_num_sorted_t const pbkdf2_passlib_names[] = {
        { L("sha1"),            FR_SSHA1 },
        { L("sha256"),          FR_SSHA2_256 },
        { L("sha512"),          FR_SSHA2_512 }
};
static size_t pbkdf2_passlib_names_len = NUM_ELEMENTS(pbkdf2_passlib_names);
#endif
 
static fr_dict_attr_t const **pap_alloweds;
 
/*
 *      Authorize the user for PAP authentication.
 *
 *      This isn't strictly necessary, but it does make the
 *      server simpler to configure.
 */
static unlang_action_t CC_HINT(nonnull) mod_authorize(rlm_rcode_t *p_result, module_ctx_t const *mctx, request_t *request)
{
        rlm_pap_t const         *inst = talloc_get_type_abort_const(mctx->mi->data, rlm_pap_t);
        pap_call_env_t          *env_data = talloc_get_type_abort(mctx->env_data, pap_call_env_t);
 
        if (fr_pair_find_by_da(&request->control_pairs, NULL, attr_auth_type) != NULL) {
                RDEBUG3("Auth-Type is already set.  Not setting 'Auth-Type := %s'", mctx->mi->name);
                RETURN_MODULE_NOOP;
        }
 
        if (env_data->password.type != FR_TYPE_STRING) {
                RDEBUG2("No %s attribute in the request.  Cannot do PAP", env_data->password_tmpl->name);
                RETURN_MODULE_NOOP;
        }
 
        if (!inst->auth_type) {
                WARN("No 'authenticate %s {...}' section or 'Auth-Type = %s' set.  Cannot setup PAP authentication.",
                     mctx->mi->name, mctx->mi->name);
                RETURN_MODULE_NOOP;
        }
 
        if (!module_rlm_section_type_set(request, attr_auth_type, inst->auth_type)) RETURN_MODULE_NOOP;
 
        RETURN_MODULE_UPDATED;
}
 
/*
 *      PAP authentication functions
 */
 
static unlang_action_t CC_HINT(nonnull) pap_auth_clear(rlm_rcode_t *p_result,
                                                       UNUSED rlm_pap_t const *inst, request_t *request,
                                                       fr_pair_t const *known_good, fr_value_box_t const *password)
{
        if ((known_good->vp_length != password->vb_length) ||
            (fr_digest_cmp(known_good->vp_octets, password->vb_octets, known_good->vp_length) != 0)) {
                REDEBUG("Cleartext password does not match \"known good\" password");
                REDEBUG3("Password   : %pV", password);
                REDEBUG3("Expected   : %pV", &known_good->data);
                RETURN_MODULE_REJECT;
        }
        RETURN_MODULE_OK;
}
 
#ifdef HAVE_CRYPT
static unlang_action_t CC_HINT(nonnull) pap_auth_crypt(rlm_rcode_t *p_result,
                                                       UNUSED rlm_pap_t const *inst, request_t *request,
                                                       fr_pair_t const *known_good, fr_value_box_t const *password)
{
        char    *crypt_out;
        int     cmp = 0;
 
#ifdef HAVE_CRYPT_R
        struct crypt_data crypt_data = { .initialized = 0 };
 
        crypt_out = crypt_r(password->vb_strvalue, known_good->vp_strvalue, &crypt_data);
        if (crypt_out) cmp = strcmp(known_good->vp_strvalue, crypt_out);
#else
        /*
         *      Ensure we're thread-safe, as crypt() isn't.
         */
        pthread_mutex_lock(&fr_crypt_mutex);
        crypt_out = crypt(password->vb_strvalue, known_good->vp_strvalue);
 
        /*
         *      Got something, check it within the lock.  This is
         *      faster than copying it to a local buffer, and the
         *      time spent within the lock is critical.
         */
        if (crypt_out) cmp = strcmp(known_good->vp_strvalue, crypt_out);
        pthread_mutex_unlock(&fr_crypt_mutex);
#endif
 
        /*
         *      Error.
         */
        if (!crypt_out || (cmp != 0)) {
                REDEBUG("Crypt digest does not match \"known good\" digest");
                RETURN_MODULE_REJECT;
        }
 
        RETURN_MODULE_OK;
}
#endif
 
static unlang_action_t CC_HINT(nonnull) pap_auth_md5(rlm_rcode_t *p_result,
                                                     UNUSED rlm_pap_t const *inst, request_t *request,
                                                     fr_pair_t const *known_good, fr_value_box_t const *password)
{
        uint8_t digest[MD5_DIGEST_LENGTH];
 
        if (known_good->vp_length != MD5_DIGEST_LENGTH) {
                REDEBUG("\"known-good\" MD5 password has incorrect length, expected 16 got %zu", known_good->vp_length);
                RETURN_MODULE_INVALID;
        }
 
        fr_md5_calc(digest, password->vb_octets, password->vb_length);
 
        if (fr_digest_cmp(digest, known_good->vp_octets, known_good->vp_length) != 0) {
                REDEBUG("MD5 digest does not match \"known good\" digest");
                REDEBUG3("Password   : %pV", password);
                REDEBUG3("Calculated : %pH", fr_box_octets(digest, MD5_DIGEST_LENGTH));
                REDEBUG3("Expected   : %pH", fr_box_octets(known_good->vp_octets, MD5_DIGEST_LENGTH));
                RETURN_MODULE_REJECT;
        }
 
        RETURN_MODULE_OK;
}
 
 
static unlang_action_t CC_HINT(nonnull) pap_auth_smd5(rlm_rcode_t *p_result,
                                                      UNUSED rlm_pap_t const *inst, request_t *request,
                                                      fr_pair_t const *known_good, fr_value_box_t const *password)
{
        fr_md5_ctx_t    *md5_ctx;
        uint8_t         digest[MD5_DIGEST_LENGTH];
 
        if (known_good->vp_length <= MD5_DIGEST_LENGTH) {
                REDEBUG("\"known-good\" Password.SMD5 has incorrect length, expected 16 got %zu", known_good->vp_length);
                RETURN_MODULE_INVALID;
        }
 
        md5_ctx = fr_md5_ctx_alloc_from_list();
        fr_md5_update(md5_ctx, password->vb_octets, password->vb_length);
        fr_md5_update(md5_ctx, known_good->vp_octets + MD5_DIGEST_LENGTH, known_good->vp_length - MD5_DIGEST_LENGTH);
        fr_md5_final(digest, md5_ctx);
        fr_md5_ctx_free_from_list(&md5_ctx);
 
        /*
         *      Compare only the MD5 hash results, not the salt.
         */
        if (fr_digest_cmp(digest, known_good->vp_octets, MD5_DIGEST_LENGTH) != 0) {
                REDEBUG("SMD5 digest does not match \"known good\" digest");
                REDEBUG3("Password   : %pV", password);
                REDEBUG3("Calculated : %pH", fr_box_octets(digest, MD5_DIGEST_LENGTH));
                REDEBUG3("Expected   : %pH", fr_box_octets(known_good->vp_octets, MD5_DIGEST_LENGTH));
                RETURN_MODULE_REJECT;
        }
 
        RETURN_MODULE_OK;
}
 
static unlang_action_t CC_HINT(nonnull) pap_auth_sha1(rlm_rcode_t *p_result,
                                                      UNUSED rlm_pap_t const *inst, request_t *request,
                                                      fr_pair_t const *known_good, fr_value_box_t const *password)
{
        fr_sha1_ctx     sha1_context;
        uint8_t         digest[SHA1_DIGEST_LENGTH];
 
        if (known_good->vp_length != SHA1_DIGEST_LENGTH) {
                REDEBUG("\"known-good\" Password.SHA1 has incorrect length, expected 20 got %zu", known_good->vp_length);
                RETURN_MODULE_INVALID;
        }
 
        fr_sha1_init(&sha1_context);
        fr_sha1_update(&sha1_context, password->vb_octets, password->vb_length);
        fr_sha1_final(digest,&sha1_context);
 
        if (fr_digest_cmp(digest, known_good->vp_octets, known_good->vp_length) != 0) {
                REDEBUG("SHA1 digest does not match \"known good\" digest");
                REDEBUG3("Password   : %pV", password);
                REDEBUG3("Calculated : %pH", fr_box_octets(digest, SHA1_DIGEST_LENGTH));
                REDEBUG3("Expected   : %pH", fr_box_octets(known_good->vp_octets, SHA1_DIGEST_LENGTH));
                RETURN_MODULE_REJECT;
        }
 
        RETURN_MODULE_OK;
}
 
static unlang_action_t CC_HINT(nonnull) pap_auth_ssha1(rlm_rcode_t *p_result,
                                                       UNUSED rlm_pap_t const *inst, request_t *request,
                                                       fr_pair_t const *known_good, fr_value_box_t const *password)
{
        fr_sha1_ctx     sha1_context;
        uint8_t         digest[SHA1_DIGEST_LENGTH];
 
        if (known_good->vp_length <= SHA1_DIGEST_LENGTH) {
                REDEBUG("\"known-good\" Password.SSHA has incorrect length, expected > 20 got %zu", known_good->vp_length);
                RETURN_MODULE_INVALID;
        }
 
        fr_sha1_init(&sha1_context);
        fr_sha1_update(&sha1_context, password->vb_octets, password->vb_length);
 
        fr_sha1_update(&sha1_context, known_good->vp_octets + SHA1_DIGEST_LENGTH, known_good->vp_length - SHA1_DIGEST_LENGTH);
        fr_sha1_final(digest, &sha1_context);
 
        if (fr_digest_cmp(digest, known_good->vp_octets, SHA1_DIGEST_LENGTH) != 0) {
                REDEBUG("SSHA digest does not match \"known good\" digest");
                REDEBUG3("Password   : %pV", password);
                REDEBUG3("Salt       : %pH", fr_box_octets(known_good->vp_octets + SHA1_DIGEST_LENGTH,
                                                           known_good->vp_length - SHA1_DIGEST_LENGTH));
                REDEBUG3("Calculated : %pH", fr_box_octets(digest, SHA1_DIGEST_LENGTH));
                REDEBUG3("Expected   : %pH", fr_box_octets(known_good->vp_octets, SHA1_DIGEST_LENGTH));
                RETURN_MODULE_REJECT;
        }
 
        RETURN_MODULE_OK;
}
 
#ifdef HAVE_OPENSSL_EVP_H
static unlang_action_t CC_HINT(nonnull) pap_auth_evp_md(rlm_rcode_t *p_result,
                                                        UNUSED rlm_pap_t const *inst, request_t *request,
                                                        fr_pair_t const *known_good, fr_value_box_t const *password,
                                                        char const *name, EVP_MD const *md)
{
        EVP_MD_CTX      *ctx;
        uint8_t         digest[EVP_MAX_MD_SIZE];
        unsigned int    digest_len;
 
        ctx = EVP_MD_CTX_create();
        EVP_DigestInit_ex(ctx, md, NULL);
        EVP_DigestUpdate(ctx, password->vb_octets, password->vb_length);
        EVP_DigestFinal_ex(ctx, digest, &digest_len);
        EVP_MD_CTX_destroy(ctx);
 
        fr_assert((size_t) digest_len == known_good->vp_length);        /* This would be an OpenSSL bug... */
 
        if (fr_digest_cmp(digest, known_good->vp_octets, known_good->vp_length) != 0) {
                REDEBUG("%s digest does not match \"known good\" digest", name);
                REDEBUG3("Password   : %pV", password);
                REDEBUG3("Calculated : %pH", fr_box_octets(digest, digest_len));
                REDEBUG3("Expected   : %pH", &known_good->data);
                RETURN_MODULE_REJECT;
        }
 
        RETURN_MODULE_OK;
}
 
static unlang_action_t CC_HINT(nonnull) pap_auth_evp_md_salted(rlm_rcode_t *p_result,
                                                               UNUSED rlm_pap_t const *inst, request_t *request,
                                                               fr_pair_t const *known_good, fr_value_box_t const *password,
                                                               char const *name, EVP_MD const *md)
{
        EVP_MD_CTX      *ctx;
        uint8_t         digest[EVP_MAX_MD_SIZE];
        unsigned int    digest_len, min_len;
 
        min_len = EVP_MD_size(md);
        ctx = EVP_MD_CTX_create();
        EVP_DigestInit_ex(ctx, md, NULL);
        EVP_DigestUpdate(ctx, password->vb_octets, password->vb_length);
        EVP_DigestUpdate(ctx, known_good->vp_octets + min_len, known_good->vp_length - min_len);
        EVP_DigestFinal_ex(ctx, digest, &digest_len);
        EVP_MD_CTX_destroy(ctx);
 
        fr_assert((size_t) digest_len == min_len);      /* This would be an OpenSSL bug... */
 
        /*
         *      Only compare digest_len bytes, the rest is salt.
         */
        if (fr_digest_cmp(digest, known_good->vp_octets, (size_t)digest_len) != 0) {
                REDEBUG("%s digest does not match \"known good\" digest", name);
                REDEBUG3("Password   : %pV", password);
                REDEBUG3("Salt       : %pH",
                         fr_box_octets(known_good->vp_octets + digest_len, known_good->vp_length - digest_len));
                REDEBUG3("Calculated : %pH", fr_box_octets(digest, digest_len));
                REDEBUG3("Expected   : %pH", fr_box_octets(known_good->vp_octets, digest_len));
                RETURN_MODULE_REJECT;
        }
 
        RETURN_MODULE_OK;
}
 
/** Define a new OpenSSL EVP based password hashing function
 *
 */
#define PAP_AUTH_EVP_MD(_func, _new_func, _name, _md) \
static unlang_action_t CC_HINT(nonnull) _new_func(rlm_rcode_t *p_result, \
                                                  rlm_pap_t const *inst, request_t *request, \
                                                  fr_pair_t const *known_good, fr_value_box_t const *password) \
{ \
        return _func(p_result, inst, request, known_good, password, _name, _md); \
}
 
PAP_AUTH_EVP_MD(pap_auth_evp_md, pap_auth_sha2_224, "SHA2-224", EVP_sha224())
PAP_AUTH_EVP_MD(pap_auth_evp_md, pap_auth_sha2_256, "SHA2-256", EVP_sha256())
PAP_AUTH_EVP_MD(pap_auth_evp_md, pap_auth_sha2_384, "SHA2-384", EVP_sha384())
PAP_AUTH_EVP_MD(pap_auth_evp_md, pap_auth_sha2_512, "SHA2-512", EVP_sha512())
PAP_AUTH_EVP_MD(pap_auth_evp_md_salted, pap_auth_ssha2_224, "SSHA2-224", EVP_sha224())
PAP_AUTH_EVP_MD(pap_auth_evp_md_salted, pap_auth_ssha2_256, "SSHA2-256", EVP_sha256())
PAP_AUTH_EVP_MD(pap_auth_evp_md_salted, pap_auth_ssha2_384, "SSHA2-384", EVP_sha384())
PAP_AUTH_EVP_MD(pap_auth_evp_md_salted, pap_auth_ssha2_512, "SSHA2-512", EVP_sha512())
 
PAP_AUTH_EVP_MD(pap_auth_evp_md, pap_auth_sha3_224, "SHA3-224", EVP_sha3_224())
PAP_AUTH_EVP_MD(pap_auth_evp_md, pap_auth_sha3_256, "SHA3-256", EVP_sha3_256())
PAP_AUTH_EVP_MD(pap_auth_evp_md, pap_auth_sha3_384, "SHA3-384", EVP_sha3_384())
PAP_AUTH_EVP_MD(pap_auth_evp_md, pap_auth_sha3_512, "SHA3-512", EVP_sha3_512())
PAP_AUTH_EVP_MD(pap_auth_evp_md_salted, pap_auth_ssha3_224, "SSHA3-224", EVP_sha3_224())
PAP_AUTH_EVP_MD(pap_auth_evp_md_salted, pap_auth_ssha3_256, "SSHA3-256", EVP_sha3_256())
PAP_AUTH_EVP_MD(pap_auth_evp_md_salted, pap_auth_ssha3_384, "SSHA3-384", EVP_sha3_384())
PAP_AUTH_EVP_MD(pap_auth_evp_md_salted, pap_auth_ssha3_512, "SSHA3-512", EVP_sha3_512())
 
/** Validates Crypt::PBKDF2 LDAP format strings
 *
 * @param[out] p_result         The result of comparing the pbkdf2 hash with the password.
 * @param[in] request           The current request.
 * @param[in] str               Raw PBKDF2 string.
 * @param[in] len               Length of string.
 * @param[in] hash_names        Table containing valid hash names.
 * @param[in] hash_names_len    How long the table is.
 * @param[in] scheme_sep        Separation character between the scheme and the next component.
 * @param[in] iter_sep          Separation character between the iterations and the next component.
 * @param[in] salt_sep          Separation character between the salt and the next component.
 * @param[in] iter_is_base64    Whether the iterations is are encoded as base64.
 * @param[in] password          to validate.
 * @return
 *      - RLM_MODULE_REJECT
 *      - RLM_MODULE_OK
 */
static inline CC_HINT(nonnull) unlang_action_t pap_auth_pbkdf2_parse(rlm_rcode_t *p_result,
                                                                     request_t *request, const uint8_t *str, size_t len,
                                                                     fr_table_num_sorted_t const hash_names[], size_t hash_names_len,
                                                                     char scheme_sep, char iter_sep, char salt_sep,
                                                                     bool iter_is_base64, fr_value_box_t const *password)
{
        rlm_rcode_t             rcode = RLM_MODULE_INVALID;
 
        uint8_t const           *p, *q, *end;
        ssize_t                 slen;
 
        EVP_MD const            *evp_md;
        int                     digest_type;
        size_t                  digest_len;
 
        uint32_t                iterations = 1;
 
        uint8_t                 *salt = NULL;
        size_t                  salt_len;
        uint8_t                 hash[EVP_MAX_MD_SIZE];
        uint8_t                 digest[EVP_MAX_MD_SIZE];
 
        RDEBUG2("Comparing with \"known-good\" Password.PBKDF2");
 
        if (len <= 1) {
                REDEBUG("Password.PBKDF2 is too short");
                goto finish;
        }
 
        /*
         *      Parse PBKDF string = {hash_algorithm}<scheme_sep><iterations><iter_sep>b64(<salt>)<salt_sep>b64(<hash>)
         */
        p = str;
        end = p + len;
 
        q = memchr(p, scheme_sep, end - p);
        if (!q) {
                REDEBUG("Password.PBKDF2 has no component separators");
                goto finish;
        }
 
        digest_type = fr_table_value_by_substr(hash_names, (char const *)p, q - p, -1);
        switch (digest_type) {
        case FR_SSHA1:
                evp_md = EVP_sha1();
                digest_len = SHA1_DIGEST_LENGTH;
                break;
 
        case FR_SSHA2_224:
                evp_md = EVP_sha224();
                digest_len = SHA224_DIGEST_LENGTH;
                break;
 
        case FR_SSHA2_256:
                evp_md = EVP_sha256();
                digest_len = SHA256_DIGEST_LENGTH;
                break;
 
        case FR_SSHA2_384:
                evp_md = EVP_sha384();
                digest_len = SHA384_DIGEST_LENGTH;
                break;
 
        case FR_SSHA2_512:
                evp_md = EVP_sha512();
                digest_len = SHA512_DIGEST_LENGTH;
                break;
 
        case FR_SSHA3_224:
                evp_md = EVP_sha3_224();
                digest_len = SHA224_DIGEST_LENGTH;
                break;
 
        case FR_SSHA3_256:
                evp_md = EVP_sha3_256();
                digest_len = SHA256_DIGEST_LENGTH;
                break;
 
        case FR_SSHA3_384:
                evp_md = EVP_sha3_384();
                digest_len = SHA384_DIGEST_LENGTH;
                break;
 
        case FR_SSHA3_512:
                evp_md = EVP_sha3_512();
                digest_len = SHA512_DIGEST_LENGTH;
                break;
 
        default:
                REDEBUG("Unknown PBKDF2 hash method \"%.*s\"", (int)(q - p), p);
                goto finish;
        }
 
        p = q + 1;
 
        if (((end - p) < 1) || !(q = memchr(p, iter_sep, end - p))) {
                REDEBUG("Password.PBKDF2 missing iterations component");
                goto finish;
        }
 
        if ((q - p) == 0) {
                REDEBUG("Password.PBKDF2 iterations component too short");
                goto finish;
        }
 
        /*
         *      If it's not base64 encoded, assume it's ascii
         */
        if (!iter_is_base64) {
                char iterations_buff[sizeof("4294967295") + 1];
                char *qq;
 
                /*
                 *      While passwords come from "trusted" sources, we don't trust them too much!
                 */
                if ((size_t) (q - p) >= sizeof(iterations_buff)) {
                        REMARKER((char const *) p, q - p,
                                 "Password.PBKDF2 iterations field is too large");
 
                        goto finish;
                }
 
                strlcpy(iterations_buff, (char const *)p, (q - p) + 1);
 
                iterations = strtoul(iterations_buff, &qq, 10);
                if (*qq != '\0') {
                        REMARKER(iterations_buff, qq - iterations_buff,
                                 "Password.PBKDF2 iterations field contains an invalid character");
 
                        goto finish;
                }
                p = q + 1;
        /*
         *      base64 encoded and big endian
         */
        } else {
                fr_strerror_clear();
                slen = fr_base64_decode(&FR_DBUFF_TMP((uint8_t *)&iterations, sizeof(iterations)),
                                        &FR_SBUFF_IN((char const *)p, (char const *)q), false, false);
                if (slen <= 0) {
                        RPEDEBUG("Failed decoding Password.PBKDF2 iterations component (%.*s)", (int)(q - p), p);
                        goto finish;
                }
                if (slen != sizeof(iterations)) {
                        REDEBUG("Decoded Password.PBKDF2 iterations component is wrong size");
                }
 
                iterations = ntohl(iterations);
 
                p = q + 1;
        }
 
        /*
         *      0 iterations is invalid (we need at least one)
         */
        if (iterations == 0) iterations = 1;
 
        if (((end - p) < 1) || !(q = memchr(p, salt_sep, end - p))) {
                REDEBUG("Password.PBKDF2 missing salt component");
                goto finish;
        }
 
        if ((q - p) == 0) {
                REDEBUG("Password.PBKDF2 salt component too short");
                goto finish;
        }
 
        MEM(salt = talloc_array(request, uint8_t, FR_BASE64_DEC_LENGTH(q - p)));
        slen = fr_base64_decode(&FR_DBUFF_TMP(salt, talloc_array_length(salt)),
                                &FR_SBUFF_IN((char const *) p, (char const *)q), false, false);
        if (slen <= 0) {
                RPEDEBUG("Failed decoding Password.PBKDF2 salt component");
                goto finish;
        }
        salt_len = (size_t)slen;
 
        p = q + 1;
 
        if ((q - p) == 0) {
                REDEBUG("Password.PBKDF2 hash component too short");
                goto finish;
        }
 
        slen = fr_base64_decode(&FR_DBUFF_TMP(hash, sizeof(hash)),
                                &FR_SBUFF_IN((char const *)p, (char const *)end), false, false);
        if (slen <= 0) {
                RPEDEBUG("Failed decoding Password.PBKDF2 hash component");
                goto finish;
        }
 
        if ((size_t)slen != digest_len) {
                REDEBUG("Password.PBKDF2 hash component length is incorrect for hash type, expected %zu, got %zd",
                        digest_len, slen);
 
                RHEXDUMP2(hash, slen, "hash component");
 
                goto finish;
        }
 
        RDEBUG2("PBKDF2 %s: Iterations %u, salt length %zu, hash length %zd",
                fr_table_str_by_value(pbkdf2_crypt_names, digest_type, "<UNKNOWN>"),
                iterations, salt_len, slen);
 
        /*
         *      Hash and compare
         */
        if (PKCS5_PBKDF2_HMAC((char const *)password->vb_octets, (int)password->vb_length,
                              (unsigned char const *)salt, (int)salt_len,
                              (int)iterations,
                              evp_md,
                              (int)digest_len, (unsigned char *)digest) == 0) {
                fr_tls_log(request, "PBKDF2 digest failure");
                goto finish;
        }
 
        if (fr_digest_cmp(digest, hash, (size_t)digest_len) != 0) {
                REDEBUG("PBKDF2 digest does not match \"known good\" digest");
                REDEBUG3("Salt       : %pH", fr_box_octets(salt, salt_len));
                REDEBUG3("Calculated : %pH", fr_box_octets(digest, digest_len));
                REDEBUG3("Expected   : %pH", fr_box_octets(hash, slen));
                rcode = RLM_MODULE_REJECT;
        } else {
                rcode = RLM_MODULE_OK;
        }
 
finish:
        talloc_free(salt);
 
        RETURN_MODULE_RCODE(rcode);
}
 
static inline unlang_action_t CC_HINT(nonnull) pap_auth_pbkdf2(rlm_rcode_t *p_result,
                                                               UNUSED rlm_pap_t const *inst,
                                                               request_t *request,
                                                               fr_pair_t const *known_good, fr_value_box_t const *password)
{
        uint8_t const *p = known_good->vp_octets, *q, *end = p + known_good->vp_length;
 
        if (end - p < 2) {
                REDEBUG("Password.PBKDF2 too short");
                RETURN_MODULE_INVALID;
        }
 
        /*
         *      If it doesn't begin with a $ assume
         *      It's Crypt::PBKDF2 LDAP format
         *
         *      {X-PBKDF2}<digest>:<b64 rounds>:<b64_salt>:<b64_hash>
         */
        if (*p != '$') {
                /*
                 *      Strip the header if it's present
                 */
                if (*p == '{') {
                        q = memchr(p, '}', end - p);
                        p = q + 1;
                }
                return pap_auth_pbkdf2_parse(p_result, request, p, end - p,
                                             pbkdf2_crypt_names, pbkdf2_crypt_names_len,
                                             ':', ':', ':', true, password);
        }
 
        /*
         *      Crypt::PBKDF2 Crypt format
         *
         *      $PBKDF2$<digest>:<rounds>:<b64_salt>$<b64_hash>
         */
        if ((size_t)(end - p) >= sizeof("$PBKDF2$") && (memcmp(p, "$PBKDF2$", sizeof("$PBKDF2$") - 1) == 0)) {
                p += sizeof("$PBKDF2$") - 1;
                return pap_auth_pbkdf2_parse(p_result, request, p, end - p,
                                             pbkdf2_crypt_names, pbkdf2_crypt_names_len,
                                             ':', ':', '$', false, password);
        }
 
        /*
         *      Python's passlib format
         *
         *      $pbkdf2-<digest>$<rounds>$<alt_b64_salt>$<alt_b64_hash>
         *
         *      Note: Our base64 functions also work with alt_b64
         */
        if ((size_t)(end - p) >= sizeof("$pbkdf2-") && (memcmp(p, "$pbkdf2-", sizeof("$pbkdf2-") - 1) == 0)) {
                p += sizeof("$pbkdf2-") - 1;
                return pap_auth_pbkdf2_parse(p_result, request, p, end - p,
                                             pbkdf2_passlib_names, pbkdf2_passlib_names_len,
                                             '$', '$', '$', false, password);
        }
 
        REDEBUG("Can't determine format of Password.PBKDF2");
 
        RETURN_MODULE_INVALID;
}
#endif
 
static unlang_action_t CC_HINT(nonnull) pap_auth_nt(rlm_rcode_t *p_result,
                                                    UNUSED rlm_pap_t const *inst, request_t *request,
                                                    fr_pair_t const *known_good, fr_value_box_t const *password)
{
        ssize_t len;
        uint8_t digest[MD4_DIGEST_LENGTH];
        uint8_t ucs2[512];
 
        RDEBUG2("Comparing with \"known-good\" Password.NT");
 
        if (known_good->vp_length != MD4_DIGEST_LENGTH) {
                REDEBUG("\"known good\" Password.NT has incorrect length, expected 16 got %zu", known_good->vp_length);
                RETURN_MODULE_INVALID;
        }
 
        len = fr_utf8_to_ucs2(ucs2, sizeof(ucs2),
                              password->vb_strvalue, password->vb_length);
        if (len < 0) {
                REDEBUG("User-Password is not in UCS2 format");
                RETURN_MODULE_INVALID;
        }
 
        fr_md4_calc(digest, (uint8_t *)ucs2, len);
 
        if (fr_digest_cmp(digest, known_good->vp_octets, known_good->vp_length) != 0) {
                REDEBUG("NT digest does not match \"known good\" digest");
                REDEBUG3("Calculated : %pH", fr_box_octets(digest, sizeof(digest)));
                REDEBUG3("Expected   : %pH", &known_good->data);
                RETURN_MODULE_REJECT;
        }
 
        RETURN_MODULE_OK;
}
 
static unlang_action_t CC_HINT(nonnull) pap_auth_ns_mta_md5(rlm_rcode_t *p_result,
                                                            UNUSED rlm_pap_t const *inst, request_t *request,
                                                            fr_pair_t const *known_good, fr_value_box_t const *password)
{
        uint8_t digest[128];
        uint8_t buff[FR_MAX_STRING_LEN];
        uint8_t buff2[FR_MAX_STRING_LEN + 50];
        fr_dbuff_t digest_dbuff = FR_DBUFF_TMP(digest, sizeof(digest));
 
        RDEBUG2("Using Password.NT-MTA-MD5");
 
        if (known_good->vp_length != 64) {
                REDEBUG("\"known good\" Password.NS-MTA-MD5 has incorrect length, expected 64 got %zu",
                        known_good->vp_length);
                RETURN_MODULE_INVALID;
        }
 
        /*
         *      Sanity check the value of Password.NS-MTA-MD5
         */
        if (fr_base16_decode(NULL, &digest_dbuff,
                       &FR_SBUFF_IN(known_good->vp_strvalue, known_good->vp_length), false) != 16) {
                REDEBUG("\"known good\" Password.NS-MTA-MD5 has invalid value");
                RETURN_MODULE_INVALID;
        }
 
        /*
         *      Ensure we don't have buffer overflows.
         *
         *      This really: sizeof(buff) - 2 - 2*32 - strlen(passwd)
         */
        if (password->vb_length >= (sizeof(buff) - 2 - 2 * 32)) {
                REDEBUG("\"known good\" Password.NS-MTA-MD5 is too long");
                RETURN_MODULE_INVALID;
        }
 
        /*
         *      Set up the algorithm.
         */
        {
                uint8_t *p = buff2;
 
                memcpy(p, &known_good->vp_octets[32], 32);
                p += 32;
                *(p++) = 89;
                memcpy(p, password->vb_strvalue, password->vb_length);
                p += password->vb_length;
                *(p++) = 247;
                memcpy(p, &known_good->vp_octets[32], 32);
                p += 32;
 
                fr_md5_calc(buff, (uint8_t *) buff2, p - buff2);
        }
 
        if (fr_digest_cmp(fr_dbuff_start(&digest_dbuff), buff, 16) != 0) {
                REDEBUG("NS-MTA-MD5 digest does not match \"known good\" digest");
                RETURN_MODULE_REJECT;
        }
 
        RETURN_MODULE_OK;
}
 
/** Auth func for password types that should have been normalised away
 *
 */
static unlang_action_t CC_HINT(nonnull) pap_auth_dummy(rlm_rcode_t *p_result,
                                                       UNUSED rlm_pap_t const *inst, UNUSED request_t *request,
                                                       UNUSED fr_pair_t const *known_good, UNUSED fr_value_box_t const *password)
{
        RETURN_MODULE_FAIL;
}
 
/** Table of password types we can process
 *
 */
static const pap_auth_func_t auth_func_table[] = {
        [FR_CLEARTEXT]  = pap_auth_clear,
        [FR_MD5]        = pap_auth_md5,
        [FR_SMD5]       = pap_auth_smd5,
 
#ifdef HAVE_CRYPT
        [FR_CRYPT]      = pap_auth_crypt,
#endif
        [FR_NS_MTA_MD5] = pap_auth_ns_mta_md5,
        [FR_NT]         = pap_auth_nt,
        [FR_WITH_HEADER] = pap_auth_dummy,
        [FR_SHA1]       = pap_auth_sha1,
        [FR_SSHA1]      = pap_auth_ssha1,
 
#ifdef HAVE_OPENSSL_EVP_H
        [FR_PBKDF2]     = pap_auth_pbkdf2,
        [FR_SHA2]       = pap_auth_dummy,
        [FR_SHA2_224]   = pap_auth_sha2_224,
        [FR_SHA2_256]   = pap_auth_sha2_256,
        [FR_SHA2_384]   = pap_auth_sha2_384,
        [FR_SHA2_512]   = pap_auth_sha2_512,
        [FR_SSHA2_224]  = pap_auth_ssha2_224,
        [FR_SSHA2_256]  = pap_auth_ssha2_256,
        [FR_SSHA2_384]  = pap_auth_ssha2_384,
        [FR_SSHA2_512]  = pap_auth_ssha2_512,
        [FR_SHA3]       = pap_auth_dummy,
        [FR_SHA3_224]   = pap_auth_sha3_224,
        [FR_SHA3_256]   = pap_auth_sha3_256,
        [FR_SHA3_384]   = pap_auth_sha3_384,
        [FR_SHA3_512]   = pap_auth_sha3_512,
        [FR_SSHA3_224]  = pap_auth_ssha3_224,
        [FR_SSHA3_256]  = pap_auth_ssha3_256,
        [FR_SSHA3_384]  = pap_auth_ssha3_384,
        [FR_SSHA3_512]  = pap_auth_ssha3_512,
#endif  /* HAVE_OPENSSL_EVP_H */
};
 
/*
 *      Authenticate the user via one of any well-known password.
 */
static unlang_action_t CC_HINT(nonnull) mod_authenticate(rlm_rcode_t *p_result, module_ctx_t const *mctx, request_t *request)
{
        rlm_pap_t const         *inst = talloc_get_type_abort_const(mctx->mi->data, rlm_pap_t);
        fr_pair_t               *known_good;
        rlm_rcode_t             rcode = RLM_MODULE_INVALID;
        pap_auth_func_t         auth_func;
        bool                    ephemeral;
        pap_call_env_t          *env_data = talloc_get_type_abort(mctx->env_data, pap_call_env_t);
 
        if (env_data->password.type != FR_TYPE_STRING) {
                REDEBUG("You set 'Auth-Type = PAP' for a request that does not contain a %s attribute!",
                        env_data->password_tmpl->name);
                RETURN_MODULE_INVALID;
        }
 
        /*
         *      The user MUST supply a non-zero-length password.
         */
        if (env_data->password.vb_length == 0) {
                REDEBUG("Password must not be empty");
                RETURN_MODULE_INVALID;
        }
 
        if (RDEBUG_ENABLED3) {
                RDEBUG3("Login attempt with %s = %pV (%zd)", env_data->password_tmpl->name,
                        &env_data->password, env_data->password.vb_length);
        } else {
                RDEBUG2("Login attempt with password");
        }
 
        /*
         *      Retrieve the normalised version of
         *      the known_good password, without
         *      mangling the current password attributes
         *      in the request.
         */
        known_good = password_find(&ephemeral, request, request,
                                   pap_alloweds, talloc_array_length(pap_alloweds),
                                   inst->normify);
        if (!known_good) {
                REDEBUG("No \"known good\" password found for user");
                RETURN_MODULE_FAIL;
        }
 
        fr_assert(known_good->da->attr < NUM_ELEMENTS(auth_func_table));
 
        auth_func = auth_func_table[known_good->da->attr];
        fr_assert(auth_func);
 
        if (RDEBUG_ENABLED3) {
                RDEBUG3("Comparing with \"known good\" %pP (%zu)", known_good, known_good->vp_length);
        } else {
                RDEBUG2("Comparing with \"known-good\" %s (%zu)", known_good->da->name, known_good->vp_length);
        }
 
        /*
         *      Authenticate, and return.
         */
        auth_func(&rcode, inst, request, known_good, &env_data->password);
        if (ephemeral) TALLOC_FREE(known_good);
        switch (rcode) {
        case RLM_MODULE_REJECT:
                REDEBUG("Password incorrect");
                break;
 
        case RLM_MODULE_OK:
                RDEBUG2("User authenticated successfully");
                break;
 
        default:
                break;
        }
 
        RETURN_MODULE_RCODE(rcode);
}
 
static int mod_instantiate(module_inst_ctx_t const *mctx)
{
        rlm_pap_t       *inst = talloc_get_type_abort(mctx->mi->data, rlm_pap_t);
 
        inst->auth_type = fr_dict_enum_by_name(attr_auth_type, mctx->mi->name, -1);
        if (!inst->auth_type) {
                WARN("Failed to find 'authenticate %s {...}' section.  PAP will likely not work",
                     mctx->mi->name);
        }
 
        return 0;
}
 
static int mod_load(void)
{
        size_t  i, j = 0;
        size_t  allowed = 0;
 
        /*
         *      Load the dictionaries early
         */
        if (fr_dict_autoload(rlm_pap_dict) < 0) {
                PERROR("%s", __FUNCTION__);
                return -1;
        }
        if (fr_dict_attr_autoload(rlm_pap_dict_attr) < 0) {
                PERROR("%s", __FUNCTION__);
                fr_dict_autofree(rlm_pap_dict);
                return -1;
        }
 
        /*
         *      Figure out how many password types we allow
         */
        for (i = 0; i < NUM_ELEMENTS(auth_func_table); i++) {
                if (auth_func_table[i] == NULL) continue;
 
                allowed++;
        }
 
        /*
         *      Get a list of the DAs that match are allowed
         *      functions.
         */
        pap_alloweds = talloc_array(NULL, fr_dict_attr_t const *, allowed);
        for (i = 0; i < NUM_ELEMENTS(auth_func_table); i++) {
                fr_dict_attr_t const *password_da;
 
                if (auth_func_table[i] == NULL) continue;
 
                password_da = fr_dict_attr_child_by_num(attr_root, i);
                if (!fr_cond_assert(password_da)) {
                        ERROR("Could not resolve password attribute %zu", i);
                        fr_dict_autofree(rlm_pap_dict);
                        talloc_free(pap_alloweds);
                        return -1;
                }
 
                pap_alloweds[j++] = password_da;
        }
 
        return 0;
}
 
static void mod_unload(void)
{
        talloc_free(pap_alloweds);
        fr_dict_autofree(rlm_pap_dict);
}
 
/*
 *      The module name should be the only globally exported symbol.
 *      That is, everything else should be 'static'.
 *
 *      If the module needs to temporarily modify it's instantiation
 *      data, the type should be changed to MODULE_TYPE_THREAD_UNSAFE.
 *      The server will then take care of ensuring that the module
 *      is single-threaded.
 */
extern module_rlm_t rlm_pap;
module_rlm_t rlm_pap = {
        .common = {
                .magic          = MODULE_MAGIC_INIT,
                .name           = "pap",
                .inst_size      = sizeof(rlm_pap_t),
                .onload         = mod_load,
                .unload         = mod_unload,
                .config         = module_config,
                .instantiate    = mod_instantiate
        },
        .method_group = {
                .bindings = (module_method_binding_t[]){
                        /*
                         *      Hack to support old configurations
                         */
                        { .section = SECTION_NAME("authenticate", CF_IDENT_ANY), .method = mod_authenticate, .method_env = &pap_method_env },
                        { .section = SECTION_NAME("authorize", CF_IDENT_ANY), .method = mod_authorize, .method_env = &pap_method_env },
                        { .section = SECTION_NAME(CF_IDENT_ANY, CF_IDENT_ANY), .method = mod_authorize, .method_env = &pap_method_env },
 
                        MODULE_BINDING_TERMINATOR
                }
        }
};