rlm_cipher.c

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/*
 *   This program 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: 5611496345d62f83b2c6125f95d0f3585a2f33ce $
 * @file rlm_cipher.c
 * @brief Creates dynamic expansions for encrypting/decrypting data.
 *
 * @author Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 *
 * @copyright 2018 The FreeRADIUS server project
 * @copyright 2018 Network RADIUS (legal@networkradius.com)
 *
 */
RCSID("$Id: 5611496345d62f83b2c6125f95d0f3585a2f33ce $")
 
#include <freeradius-devel/server/base.h>
#include <freeradius-devel/server/module_rlm.h>
#include <freeradius-devel/tls/base.h>
#include <freeradius-devel/tls/cert.h>
#include <freeradius-devel/tls/log.h>
#include <freeradius-devel/tls/utils.h>
#include <freeradius-devel/tls/strerror.h>
#include <freeradius-devel/unlang/xlat_func.h>
 
#include <openssl/crypto.h>
#include <openssl/pem.h>
#include <openssl/evp.h>
#include <openssl/rsa.h>
 
static int digest_type_parse(UNUSED TALLOC_CTX *ctx, void *out, UNUSED void *parent,
                             CONF_ITEM *ci, UNUSED conf_parser_t const *rule);
static int cipher_rsa_padding_type_parse(UNUSED TALLOC_CTX *ctx, void *out, UNUSED void *parent,
                                         CONF_ITEM *ci, UNUSED conf_parser_t const *rule);
static int cipher_type_parse(UNUSED TALLOC_CTX *ctx, void *out, UNUSED void *parent,
                             CONF_ITEM *ci, UNUSED conf_parser_t const *rule);
 
static int cipher_rsa_private_key_file_load(UNUSED TALLOC_CTX *ctx, void *out, UNUSED void *parent,
                                            CONF_ITEM *ci, UNUSED conf_parser_t const *rule);
static int cipher_rsa_certificate_file_load(TALLOC_CTX *ctx, void *out, UNUSED void *parent,
                                            CONF_ITEM *ci, UNUSED conf_parser_t const *rule);
 
typedef enum {
        RLM_CIPHER_TYPE_INVALID = 0,
        RLM_CIPHER_TYPE_RSA = 1,
        RLM_CIPHER_TYPE_SYMMETRIC = 2                           //!< Any symmetric cipher available via
                                                                ///< OpenSSL's EVP interface.
} cipher_type_t;
 
/** Certificate validation modes
 *
 */
typedef enum {
        CIPHER_CERT_VERIFY_INVALID = 0,
 
        CIPHER_CERT_VERIFY_HARD,                                //!< Fail if the certificate isn't valid.
        CIPHER_CERT_VERIFY_SOFT,                                //!< Warn if the certificate isn't valid.
        CIPHER_CERT_VERIFY_NONE                                 //!< Don't check to see if the we're between
                                                                ///< notBefore or notAfter.
} cipher_cert_verify_mode_t;
 
typedef enum {
        CIPHER_CERT_ATTR_UNKNOWN = 0,                           //!< Unrecognised attribute.
        CIPHER_CERT_ATTR_SERIAL,                                //!< Certificate's serial number.
        CIPHER_CERT_ATTR_FINGERPRINT,                           //!< Dynamically calculated fingerprint.
        CIPHER_CERT_ATTR_NOT_BEFORE,                            //!< Time the certificate becomes valid.
        CIPHER_CERT_ATTR_NOT_AFTER                              //!< Time the certificate expires.
} cipher_cert_attributes_t;
 
/** Public key types
 *
 */
static fr_table_num_sorted_t const pkey_types[] = {
        { L("DH"),      EVP_PKEY_DH             },
        { L("DSA"),     EVP_PKEY_DSA            },
        { L("EC"),      EVP_PKEY_EC             },
        { L("RSA"),     EVP_PKEY_RSA            }
};
static size_t pkey_types_len = NUM_ELEMENTS(pkey_types);
 
/** The type of padding used
 *
 */
static fr_table_num_sorted_t const cipher_rsa_padding[] = {
        { L("none"),    RSA_NO_PADDING          },
        { L("oaep"),    RSA_PKCS1_OAEP_PADDING  },              /* PKCS OAEP padding */
        { L("pkcs"),    RSA_PKCS1_PADDING       },              /* PKCS 1.5 */
        { L("x931"),    RSA_X931_PADDING        }
};
static size_t cipher_rsa_padding_len = NUM_ELEMENTS(cipher_rsa_padding);
 
static fr_table_num_sorted_t const cipher_type[] = {
        { L("rsa"),             RLM_CIPHER_TYPE_RSA             },
        { L("symmetric"),       RLM_CIPHER_TYPE_SYMMETRIC       }
};
static size_t cipher_type_len = NUM_ELEMENTS(cipher_type);
 
static fr_table_num_sorted_t const cipher_cert_verify_mode_table[] = {
        { L("hard"),    CIPHER_CERT_VERIFY_HARD },
        { L("none"),    CIPHER_CERT_VERIFY_NONE },
        { L("soft"),    CIPHER_CERT_VERIFY_SOFT }
};
static size_t cipher_cert_verify_mode_table_len = NUM_ELEMENTS(cipher_cert_verify_mode_table);
 
/** Public key types
 *
 */
static fr_table_num_sorted_t const cert_attributes[] = {
        { L("fingerprint"),     CIPHER_CERT_ATTR_FINGERPRINT    },
        { L("notAfter"),        CIPHER_CERT_ATTR_NOT_AFTER      },
        { L("notBefore"),       CIPHER_CERT_ATTR_NOT_BEFORE     },
        { L("serial"),          CIPHER_CERT_ATTR_SERIAL         },
};
static size_t cert_attributes_len = NUM_ELEMENTS(cert_attributes);
 
typedef struct {
        EVP_PKEY_CTX            *evp_encrypt_ctx;               //!< Pre-allocated evp_pkey_ctx.
        EVP_PKEY_CTX            *evp_sign_ctx;                  //!< Pre-allocated evp_pkey_ctx.
        EVP_PKEY_CTX            *evp_decrypt_ctx;               //!< Pre-allocated evp_pkey_ctx.
        EVP_PKEY_CTX            *evp_verify_ctx;                //!< Pre-allocated evp_pkey_ctx.
 
        EVP_MD_CTX              *evp_md_ctx;                    //!< Pre-allocated evp_md_ctx for sign and verify.
        uint8_t                 *digest_buff;                   //!< Pre-allocated digest buffer.
} rlm_cipher_rsa_thread_inst_t;
 
/** Configuration for the OAEP padding method
 *
 */
typedef struct {
        EVP_MD                  *oaep_digest;                   //!< Padding digest type.
        EVP_MD                  *mgf1_digest;                   //!< Masking function digest.
 
        char const              *label;                         //!< Additional input to the hashing function.
} cipher_rsa_oaep_t;
 
 
 
/** Configuration for RSA encryption/decryption/signing
 *
 */
typedef struct {
        char const              *private_key_password;          //!< Password to decrypt the private key.
        char const              *random_file;                   //!< If set, we read 10K of data (or the complete file)
                                                                //!< and use it to seed OpenSSL's PRNG.
 
        EVP_PKEY                *private_key_file;              //!< Private key file.
        EVP_PKEY                *certificate_file;              //!< Public (certificate) file.
        X509                    *x509_certificate_file;         //!< Needed for extracting certificate attributes.
 
        cipher_cert_verify_mode_t verify_mode;                  //!< How hard we try to verify the certificate.
        fr_unix_time_t          not_before;                     //!< Certificate isn't valid before this time.
        fr_unix_time_t          not_after;                      //!< Certificate isn't valid after this time.
 
        int                     padding;                        //!< Type of padding to apply to the plaintext
                                                                ///< or ciphertext before feeding it to RSA crypto
                                                                ///< functions.
 
        EVP_MD                  *sig_digest;                    //!< Signature digest type.
 
        cipher_rsa_oaep_t       *oaep;                          //!< OAEP can use a configurable message digest type
} cipher_rsa_t;
 
/** Instance configuration
 *
 */
typedef struct {
        cipher_type_t           type;                           //!< Type of encryption to use.
 
        /** Supported cipher types
         *
         */
        union {
                cipher_rsa_t    *rsa;                           //!< Use RSA encryption (with optional padding).
        };
} rlm_cipher_t;
 
/** Configuration for the RSA-PCKS1-OAEP padding scheme
 *
 */
static const conf_parser_t rsa_oaep_config[] = {
        { FR_CONF_OFFSET_TYPE_FLAGS("oaep_digest", FR_TYPE_VOID, CONF_FLAG_NOT_EMPTY, cipher_rsa_oaep_t, oaep_digest), .func = digest_type_parse, .dflt = "sha256" },
        { FR_CONF_OFFSET_TYPE_FLAGS("mgf1_digest", FR_TYPE_VOID, CONF_FLAG_NOT_EMPTY, cipher_rsa_oaep_t, mgf1_digest), .func = digest_type_parse, .dflt = "sha256" },
        { FR_CONF_OFFSET("label", cipher_rsa_oaep_t, label) },
 
        CONF_PARSER_TERMINATOR
};
 
/** Configuration for the RSA cipher type
 *
 */
static const conf_parser_t rsa_config[] = {
        { FR_CONF_OFFSET("verify_mode", cipher_rsa_t, verify_mode),
                         .func = cf_table_parse_int,
                         .uctx = &(cf_table_parse_ctx_t){
                                .table = cipher_cert_verify_mode_table,
                                .len = &cipher_cert_verify_mode_table_len
                         },
                         .dflt = "hard" }, /* Must come before certificate file */
 
        { FR_CONF_OFFSET_FLAGS("private_key_password", CONF_FLAG_SECRET, cipher_rsa_t, private_key_password) }, /* Must come before private_key */
        { FR_CONF_OFFSET_TYPE_FLAGS("private_key_file", FR_TYPE_VOID, CONF_FLAG_NOT_EMPTY, cipher_rsa_t, private_key_file), .func = cipher_rsa_private_key_file_load },
        { FR_CONF_OFFSET_TYPE_FLAGS("certificate_file", FR_TYPE_VOID, CONF_FLAG_NOT_EMPTY, cipher_rsa_t, certificate_file), .func = cipher_rsa_certificate_file_load },
 
        { FR_CONF_OFFSET("random_file", cipher_rsa_t, random_file) },
 
        { FR_CONF_OFFSET_TYPE_FLAGS("signature_digest", FR_TYPE_VOID, CONF_FLAG_NOT_EMPTY, cipher_rsa_t, sig_digest), .func = digest_type_parse, .dflt = "sha256" },
 
        { FR_CONF_OFFSET_TYPE_FLAGS("padding_type", FR_TYPE_VOID, CONF_FLAG_NOT_EMPTY, cipher_rsa_t, padding), .func = cipher_rsa_padding_type_parse, .dflt = "pkcs" },
 
        { FR_CONF_OFFSET_SUBSECTION("oaep", 0, cipher_rsa_t, oaep, rsa_oaep_config),
                         .subcs_size = sizeof(cipher_rsa_oaep_t), .subcs_type = "cipher_rsa_oaep_t" },
 
        CONF_PARSER_TERMINATOR
};
 
/*
 *      A mapping of configuration file names to internal variables.
 */
static const conf_parser_t module_config[] = {
        { FR_CONF_OFFSET_TYPE_FLAGS("type", FR_TYPE_VOID, CONF_FLAG_NOT_EMPTY, rlm_cipher_t, type), .func = cipher_type_parse, .dflt = "rsa" },
        { FR_CONF_OFFSET_SUBSECTION("rsa", 0, rlm_cipher_t, rsa, rsa_config), .subcs_size = sizeof(cipher_rsa_t), .subcs_type = "cipher_rsa_t" },
        CONF_PARSER_TERMINATOR
};
 
/** Calls EVP_get_digestbyname() to convert the digest type
 *
 * @param[in] ctx       to allocate data in.
 * @param[out] out      EVP_MD representing the OpenSSL digest type.
 * @param[in] parent    Base structure address.
 * @param[in] ci        #CONF_PAIR specifying the name of the digest.
 * @param[in] rule      unused.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int digest_type_parse(UNUSED TALLOC_CTX *ctx, void *out, UNUSED void *parent,
                             CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        EVP_MD const    *md;
        char const      *type_str;
 
        type_str = cf_pair_value(cf_item_to_pair(ci));
        md = EVP_get_digestbyname(type_str);
        if (!md) {
                cf_log_err(ci, "Invalid digest type \"%s\"", type_str);
                return -1;
        }
 
        *((EVP_MD const **)out) = md;
 
        return 0;
}
 
/** Checks if the specified padding type is valid
 *
 * @param[in] ctx       to allocate data in.
 * @param[out] out      Padding type.
 * @param[in] parent    Base structure address.
 * @param[in] ci        #CONF_PAIR specifying the padding type..
 * @param[in] rule      unused.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int cipher_rsa_padding_type_parse(UNUSED TALLOC_CTX *ctx, void *out, UNUSED void *parent,
                                         CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        int             type;
        char const      *type_str;
 
        type_str = cf_pair_value(cf_item_to_pair(ci));
        type = fr_table_value_by_str(cipher_rsa_padding, type_str, -1);
        if (type == -1) {
                cf_log_err(ci, "Invalid padding type \"%s\"", type_str);
                return -1;
        }
 
        *((int *)out) = type;
 
        return 0;
}
 
/** Checks if the specified cipher type is valid
 *
 * @param[in] ctx       to allocate data in.
 * @param[out] out      Cipher enumeration type.
 * @param[in] parent    Base structure address.
 * @param[in] ci        #CONF_PAIR specifying the name of the type module.
 * @param[in] rule      unused.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int cipher_type_parse(UNUSED TALLOC_CTX *ctx, void *out, UNUSED void *parent, CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        cipher_type_t   type;
        char const      *type_str;
 
        type_str = cf_pair_value(cf_item_to_pair(ci));
        type = fr_table_value_by_str(cipher_type, type_str, RLM_CIPHER_TYPE_INVALID);
        switch (type) {
        case RLM_CIPHER_TYPE_RSA:
                break;
 
        case RLM_CIPHER_TYPE_SYMMETRIC:
        case RLM_CIPHER_TYPE_INVALID:
                cf_log_err(ci, "Invalid cipher type \"%s\"", type_str);
                return -1;
        }
 
        *((cipher_type_t *)out) = type;
 
        return 0;
}
 
/** Talloc destructor for freeing an EVP_PKEY (representing a certificate)
 *
 * @param[in] pkey      to free.
 * @return 0
 */
static int _evp_pkey_free(EVP_PKEY *pkey)
{
        EVP_PKEY_free(pkey);
 
        return 0;
}
 
/** Talloc destructor for freeing an X509 struct (representing a public certificate)
 *
 * @param[in] cert      to free.
 * @return 0
 */
static int _x509_cert_free(X509 *cert)
{
        X509_free(cert);
 
        return 0;
}
 
/** Load and (optionally decrypt) an RSA private key using OpenSSL functions
 *
 * @param[in] ctx       UNUSED. Although the EVP_PKEY struct will be allocated
 *                      with talloc, we need to call the specialised free
 *                      function anyway.
 * @param[out] out      Where to write the EVP_PKEY * representing the
 *                      certificate we just loaded.
 * @param[in] parent    Base structure address.
 * @param[in] ci        Config item containing the certificate path.
 * @param[in] rule      this callback was attached to.
 * @return
 *      - -1 on failure.
 *      - 0 on success.
 */
static int cipher_rsa_private_key_file_load(TALLOC_CTX *ctx, void *out, void *parent,
                                            CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        FILE            *fp;
        char const      *filename;
        cipher_rsa_t    *rsa_inst = talloc_get_type_abort(parent, cipher_rsa_t);
        EVP_PKEY        *pkey;
        int             pkey_type;
 
        filename = cf_pair_value(cf_item_to_pair(ci));
 
        fp = fopen(filename, "r");
        if (!fp) {
                cf_log_err(ci, "Failed opening private_key file \"%s\": %s", filename, fr_syserror(errno));
                return -1;
        }
 
        pkey = PEM_read_PrivateKey(fp, (EVP_PKEY **)out, fr_utils_get_private_key_password,
                                   UNCONST(void *, rsa_inst->private_key_password));
        fclose(fp);
 
        if (!pkey) {
                fr_tls_strerror_printf(NULL);
                cf_log_perr(ci, "Error loading private certificate file \"%s\"", filename);
 
                return -1;
        }
 
        pkey_type = EVP_PKEY_type(EVP_PKEY_id(pkey));
        if (pkey_type != EVP_PKEY_RSA) {
                cf_log_err(ci, "Expected certificate to contain %s private key, got %s private key",
                           fr_table_str_by_value(pkey_types, EVP_PKEY_RSA, OBJ_nid2sn(pkey_type)),
                           fr_table_str_by_value(pkey_types, pkey_type, OBJ_nid2sn(pkey_type)));
 
                EVP_PKEY_free(pkey);
                return -1;
        }
 
        talloc_set_type(pkey, EVP_PKEY);
        (void)talloc_steal(ctx, pkey);                  /* Bind lifetime to config */
        talloc_set_destructor(pkey, _evp_pkey_free);    /* Free pkey correctly on chunk free */
 
        return 0;
}
 
/** Load an RSA public key using OpenSSL functions
 *
 * @param[in] ctx       UNUSED. Although the EVP_PKEY struct will be allocated
 *                      with talloc, we need to call the specialised free
 *                      function anyway.
 * @param[out] out      Where to write the EVP_PKEY * representing the
 *                      certificate we just loaded.
 * @param[in] parent    Base structure address.
 * @param[in] ci        Config item containing the certificate path.
 * @param[in] rule      this callback was attached to.
 * @return
 *      - -1 on failure.
 *      - 0 on success.
 */
static int cipher_rsa_certificate_file_load(TALLOC_CTX *ctx, void *out, void *parent,
                                            CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        FILE            *fp;
        char const      *filename;
        cipher_rsa_t    *rsa_inst = talloc_get_type_abort(parent, cipher_rsa_t);
 
        X509            *cert;          /* X509 certificate */
        EVP_PKEY        *pkey;          /* Wrapped public key */
        int             pkey_type;
 
        filename = cf_pair_value(cf_item_to_pair(ci));
 
        fp = fopen(filename, "r");
        if (!fp) {
                cf_log_err(ci, "Failed opening certificate_file \"%s\": %s", filename, fr_syserror(errno));
                return -1;
        }
 
        /*
         *      Load the PEM encoded X509 certificate
         */
        cert = PEM_read_X509(fp, NULL, NULL, NULL);
        fclose(fp);
 
        if (!cert) {
                fr_tls_strerror_printf(NULL);
                cf_log_perr(ci, "Error loading certificate file \"%s\"", filename);
 
                return -1;
        }
 
        /*
         *      Keep the x509 structure around as we may want
         *      to extract information from fields in the cert
         *      or calculate its fingerprint.
         */
        talloc_set_type(cert, X509);
        (void)talloc_steal(ctx, cert);                  /* Bind lifetime to config */
        talloc_set_destructor(cert, _x509_cert_free);   /* Free x509 cert correctly on chunk free */
 
        /*
         *      Extract the public key from the certificate
         */
        pkey = X509_get_pubkey(cert);
        if (!pkey) {
                fr_tls_strerror_printf(NULL);
                cf_log_perr(ci, "Failed extracting public key from certificate");
 
                return -1;
        }
 
        pkey_type = EVP_PKEY_type(EVP_PKEY_id(pkey));
        if (pkey_type != EVP_PKEY_RSA) {
                cf_log_err(ci, "Expected certificate to contain %s public key, got %s public key",
                           fr_table_str_by_value(pkey_types, EVP_PKEY_RSA, "?Unknown?"),
                           fr_table_str_by_value(pkey_types, pkey_type, "?Unknown?"));
        error:
                EVP_PKEY_free(pkey);
                return -1;
        }
 
        /*
         *      Certificate validity checks
         */
        switch (fr_tls_cert_is_valid(&rsa_inst->not_before, &rsa_inst->not_after, cert)) {
        case 0:
                cf_log_debug(ci, "Certificate validity starts at %pV and ends at %pV",
                             fr_box_date(rsa_inst->not_before), fr_box_date(rsa_inst->not_after));
                break;
 
        case -1:
                cf_log_perr(ci, "Malformed certificate");
                return -1;
 
        case -2:
        case -3:
                switch (rsa_inst->verify_mode) {
                case CIPHER_CERT_VERIFY_SOFT:
                        cf_log_pwarn(ci, "Certificate validation failed");
                        break;
 
                case CIPHER_CERT_VERIFY_HARD:
                        cf_log_perr(ci, "Certificate validation failed");
                        goto error;
 
                case CIPHER_CERT_VERIFY_NONE:
                        break;
 
                case CIPHER_CERT_ATTR_UNKNOWN:
                        fr_assert(0);
                        break;
                }
        }
 
        talloc_set_type(pkey, EVP_PKEY);
        (void)talloc_steal(cert, pkey);                 /* Bind lifetime to config */
        talloc_set_destructor(pkey, _evp_pkey_free);    /* Free pkey correctly on chunk free */
 
        rsa_inst->x509_certificate_file = cert;         /* Not great, but shouldn't cause any issues */
        *(EVP_PKEY **)out = pkey;
 
        return 0;
}
 
static xlat_arg_parser_t const cipher_rsa_encrypt_xlat_arg[] = {
        { .required = true, .concat = true, .type = FR_TYPE_STRING },
        XLAT_ARG_PARSER_TERMINATOR
};
 
/** Encrypt input data
 *
 * Arguments are @verbatim(<plaintext>...)@endverbatim
 *
@verbatim
%<inst>.encrypt(<plaintext>...)
@endverbatim
 *
 * If multiple arguments are provided they will be concatenated.
 *
 * @ingroup xlat_functions
 */
static xlat_action_t cipher_rsa_encrypt_xlat(TALLOC_CTX *ctx, fr_dcursor_t *out,
                                             xlat_ctx_t const *xctx,
                                             request_t *request, fr_value_box_list_t *in)
{
        rlm_cipher_rsa_thread_inst_t    *t = talloc_get_type_abort(xctx->mctx->thread, rlm_cipher_rsa_thread_inst_t);
 
        char const                      *plaintext;
        size_t                          plaintext_len;
 
        uint8_t                         *ciphertext;
        size_t                          ciphertext_len;
 
        fr_value_box_t                  *vb;
        fr_value_box_t                  *in_head = fr_value_box_list_head(in);
 
        plaintext = in_head->vb_strvalue;
        plaintext_len = in_head->vb_length;
 
        /*
         *      Figure out the buffer we need
         */
        RHEXDUMP3((uint8_t const *)plaintext, plaintext_len, "Plaintext (%zu bytes)", plaintext_len);
        if (EVP_PKEY_encrypt(t->evp_encrypt_ctx, NULL, &ciphertext_len,
                             (unsigned char const *)plaintext, plaintext_len) <= 0) {
                fr_tls_log(request, "Failed getting length of encrypted plaintext");
                return XLAT_ACTION_FAIL;
        }
 
        MEM(vb = fr_value_box_alloc_null(ctx));
        MEM(fr_value_box_mem_alloc(vb, &ciphertext, vb, NULL, ciphertext_len, false) == 0);
        if (EVP_PKEY_encrypt(t->evp_encrypt_ctx, ciphertext, &ciphertext_len,
                             (unsigned char const *)plaintext, plaintext_len) <= 0) {
                fr_tls_log(request, "Failed encrypting plaintext");
                talloc_free(vb);
                return XLAT_ACTION_FAIL;
        }
        RHEXDUMP3(ciphertext, ciphertext_len, "Ciphertext (%zu bytes)", ciphertext_len);
        MEM(fr_value_box_mem_realloc(vb, NULL, vb, ciphertext_len) == 0);
        fr_dcursor_append(out, vb);
 
        return XLAT_ACTION_DONE;
}
 
 
static xlat_arg_parser_t const cipher_rsa_sign_xlat_arg[] = {
        { .required = true, .concat = true, .type = FR_TYPE_STRING },
        XLAT_ARG_PARSER_TERMINATOR
};
 
/** Sign input data
 *
 * Arguments are @verbatim(<plaintext>...)@endverbatim
 *
@verbatim
%<inst>.sign(<plaintext>...)
@endverbatim
 *
 * If multiple arguments are provided they will be concatenated.
 *
 * @ingroup xlat_functions
 */
static xlat_action_t cipher_rsa_sign_xlat(TALLOC_CTX *ctx, fr_dcursor_t *out,
                                          xlat_ctx_t const *xctx,
                                          request_t *request, fr_value_box_list_t *in)
{
        rlm_cipher_t const              *inst = talloc_get_type_abort_const(xctx->mctx->mi->data, rlm_cipher_t);
        rlm_cipher_rsa_thread_inst_t    *t = talloc_get_type_abort(xctx->mctx->thread, rlm_cipher_rsa_thread_inst_t);
 
        char const                      *msg;
        size_t                          msg_len;
 
        uint8_t                         *sig;
        size_t                          sig_len;
 
        unsigned int                    digest_len = 0;
 
        fr_value_box_t                  *vb;
        fr_value_box_t                  *in_head = fr_value_box_list_head(in);
 
        msg = in_head->vb_strvalue;
        msg_len = in_head->vb_length;
 
        /*
         *      First produce a digest of the message
         */
        if (unlikely(EVP_DigestInit_ex(t->evp_md_ctx, inst->rsa->sig_digest, NULL) <= 0)) {
                fr_tls_log(request, "Failed initialising message digest");
                return XLAT_ACTION_FAIL;
        }
 
        if (EVP_DigestUpdate(t->evp_md_ctx, msg, msg_len) <= 0) {
                fr_tls_log(request, "Failed ingesting message");
                return XLAT_ACTION_FAIL;
        }
 
        if (EVP_DigestFinal_ex(t->evp_md_ctx, t->digest_buff, &digest_len) <= 0) {
                fr_tls_log(request, "Failed finalising message digest");
                return XLAT_ACTION_FAIL;
        }
        fr_assert((size_t)digest_len == talloc_array_length(t->digest_buff));
 
        /*
         *      Then sign the digest
         */
        if (EVP_PKEY_sign(t->evp_sign_ctx, NULL, &sig_len, t->digest_buff, (size_t)digest_len) <= 0) {
                fr_tls_log(request, "Failed getting length of digest");
                return XLAT_ACTION_FAIL;
        }
 
        MEM(vb = fr_value_box_alloc_null(ctx));
        MEM(fr_value_box_mem_alloc(vb, &sig, vb, NULL, sig_len, false) == 0);
        if (EVP_PKEY_sign(t->evp_sign_ctx, sig, &sig_len, t->digest_buff, (size_t)digest_len) <= 0) {
                fr_tls_log(request, "Failed signing message digest");
                talloc_free(vb);
                return XLAT_ACTION_FAIL;
        }
        MEM(fr_value_box_mem_realloc(vb, NULL, vb, sig_len) == 0);
        fr_dcursor_append(out, vb);
 
        return XLAT_ACTION_DONE;
}
 
static xlat_arg_parser_t const cipher_rsa_decrypt_xlat_arg[] = {
        { .required = true, .concat = true, .type = FR_TYPE_OCTETS },
        XLAT_ARG_PARSER_TERMINATOR
};
 
/** Decrypt input data
 *
 * Arguments are @verbatim(<ciphertext>...)@endverbatim
 *
@verbatim
%<inst>.decrypt(<ciphertext>...)
@endverbatim
 *
 * If multiple arguments are provided they will be concatenated.
 *
 * @ingroup xlat_functions
 */
static xlat_action_t cipher_rsa_decrypt_xlat(TALLOC_CTX *ctx, fr_dcursor_t *out,
                                             xlat_ctx_t const *xctx,
                                             request_t *request, fr_value_box_list_t *in)
{
        rlm_cipher_rsa_thread_inst_t    *t = talloc_get_type_abort(xctx->mctx->thread, rlm_cipher_rsa_thread_inst_t);
 
        uint8_t const                   *ciphertext;
        size_t                          ciphertext_len;
 
        char                            *plaintext;
        size_t                          plaintext_len;
 
        fr_value_box_t                  *vb;
        fr_value_box_t                  *in_head = fr_value_box_list_head(in);
 
        ciphertext = in_head->vb_octets;
        ciphertext_len = in_head->vb_length;
 
        /*
         *      Decrypt the ciphertext
         */
        RHEXDUMP3(ciphertext, ciphertext_len, "Ciphertext (%zu bytes)", ciphertext_len);
        if (EVP_PKEY_decrypt(t->evp_decrypt_ctx, NULL, &plaintext_len, ciphertext, ciphertext_len) <= 0) {
                fr_tls_log(request, "Failed getting length of cleartext");
                return XLAT_ACTION_FAIL;
        }
 
        MEM(vb = fr_value_box_alloc_null(ctx));
        MEM(fr_value_box_bstr_alloc(vb, &plaintext, vb, NULL, plaintext_len, true) == 0);
        if (EVP_PKEY_decrypt(t->evp_decrypt_ctx, (unsigned char *)plaintext, &plaintext_len,
                             ciphertext, ciphertext_len) <= 0) {
                fr_tls_log(request, "Failed decrypting ciphertext");
                talloc_free(vb);
                return XLAT_ACTION_FAIL;
        }
        RHEXDUMP3((uint8_t const *)plaintext, plaintext_len, "Plaintext (%zu bytes)", plaintext_len);
        MEM(fr_value_box_bstr_realloc(vb, NULL, vb, plaintext_len) == 0);
        fr_dcursor_append(out, vb);
 
        return XLAT_ACTION_DONE;
}
 
static xlat_arg_parser_t const cipher_rsa_verify_xlat_arg[] = {
        { .required = true, .concat = false, .single = true, .type = FR_TYPE_VOID },
        { .required = true, .concat = true, .type = FR_TYPE_STRING },
        { .variadic = XLAT_ARG_VARIADIC_EMPTY_SQUASH, .concat = true,  .type = FR_TYPE_STRING },
        XLAT_ARG_PARSER_TERMINATOR
};
 
/** Verify input data
 *
 * Arguments are @verbatim(<signature>, <plaintext>...)@endverbatim
 *
@verbatim
%<inst>.verify(<signature>, <plaintext>...)
@endverbatim
 *
 * If multiple arguments are provided (after @verbatim<signature>@endverbatim)
 * they will be concatenated.
 *
 * @ingroup xlat_functions
 */
static xlat_action_t cipher_rsa_verify_xlat(TALLOC_CTX *ctx, fr_dcursor_t *out,
                                            xlat_ctx_t const *xctx,
                                            request_t *request, fr_value_box_list_t *in)
{
        rlm_cipher_t const              *inst = talloc_get_type_abort_const(xctx->mctx->mi->data, rlm_cipher_t);
        rlm_cipher_rsa_thread_inst_t    *t = talloc_get_type_abort(xctx->mctx->thread, rlm_cipher_rsa_thread_inst_t);
 
        uint8_t const                   *sig;
        size_t                          sig_len;
 
        char const                      *msg;
        size_t                          msg_len;
 
        unsigned int                    digest_len = 0;
 
        fr_value_box_t                  *vb;
        fr_value_box_t                  *in_head = fr_value_box_list_pop_head(in);
        fr_value_box_t                  *args;
 
        fr_assert(in_head);
 
        /*
         *      Don't auto-cast to octets if the signature
         *      isn't already in that form.
         *      It could be hexits or base64 or some other encoding.
         */
        if (in_head->type != FR_TYPE_OCTETS) {
                REDEBUG("Signature argument wrong type, expected %s, got %s.  "
                        "Use %%base64.decode(<text>) or %%hex_decode(<text>) if signature is armoured",
                        fr_type_to_str(FR_TYPE_OCTETS),
                        fr_type_to_str(in_head->type));
                return XLAT_ACTION_FAIL;
        }
        sig = in_head->vb_octets;
        sig_len = in_head->vb_length;
 
        /*
         *      Concat (...) args to get message data
         */
        args = fr_value_box_list_head(in);
        if (fr_value_box_list_concat_in_place(ctx,
                                              args, in, FR_TYPE_STRING,
                                              FR_VALUE_BOX_LIST_FREE, true,
                                              SIZE_MAX) < 0) {
                REDEBUG("Failed concatenating arguments to form plaintext");
                return XLAT_ACTION_FAIL;
        }
        msg = args->vb_strvalue;
        msg_len = args->vb_length;
 
        if (msg_len == 0) {
                REDEBUG("Zero length message data");
                return XLAT_ACTION_FAIL;
        }
 
        /*
         *      First produce a digest of the message
         */
        if (unlikely(EVP_DigestInit_ex(t->evp_md_ctx, inst->rsa->sig_digest, NULL) <= 0)) {
                fr_tls_log(request, "Failed initialising message digest");
                return XLAT_ACTION_FAIL;
        }
 
        if (EVP_DigestUpdate(t->evp_md_ctx, msg, msg_len) <= 0) {
                fr_tls_log(request, "Failed ingesting message");
                return XLAT_ACTION_FAIL;
        }
 
        if (EVP_DigestFinal_ex(t->evp_md_ctx, t->digest_buff, &digest_len) <= 0) {
                fr_tls_log(request, "Failed finalising message digest");
                return XLAT_ACTION_FAIL;
        }
        fr_assert((size_t)digest_len == talloc_array_length(t->digest_buff));
 
        /*
         *      Now check the signature matches what we expected
         */
        switch (EVP_PKEY_verify(t->evp_verify_ctx, sig, sig_len, t->digest_buff, (size_t)digest_len)) {
        case 1:         /* success (signature valid) */
                MEM(vb = fr_value_box_alloc(ctx, FR_TYPE_BOOL, NULL));
                vb->vb_bool = true;
                fr_dcursor_append(out, vb);
                break;
 
        case 0:         /* failure (signature not valid) */
                MEM(vb = fr_value_box_alloc(ctx, FR_TYPE_BOOL, NULL));
                vb->vb_bool = false;
                fr_dcursor_append(out, vb);
                break;
 
        default:
                fr_tls_log(request, "Failed validating signature");
                return XLAT_ACTION_FAIL;
        }
 
        return XLAT_ACTION_DONE;
}
 
static xlat_arg_parser_t const cipher_certificate_xlat_args[] = {
        { .required = true, .concat = false, .single = true, .type = FR_TYPE_STRING },
        { .required = false, .concat = false, .single = true, .type = FR_TYPE_STRING }, /* Optional hash for fingerprint mode */
        XLAT_ARG_PARSER_TERMINATOR
};
 
/** Return the fingerprint of the public certificate
 *
 * Arguments are @verbatim(<digest>)@endverbatim
 *
@verbatim
%<inst>.certificate(fingerprint, <digest>)
@endverbatim
 *
 * @ingroup xlat_functions
 */
static xlat_action_t cipher_fingerprint_xlat(TALLOC_CTX *ctx, fr_dcursor_t *out,
                                             xlat_ctx_t const *xctx,
                                             request_t *request, fr_value_box_list_t *in)
{
        rlm_cipher_t const              *inst = talloc_get_type_abort_const(xctx->mctx->mi->data, rlm_cipher_t);
        char const                      *md_name;
        EVP_MD const                    *md;
        size_t                          md_len;
        fr_value_box_t                  *vb;
        uint8_t                         *digest;
 
        {
                fr_value_box_t *digest_vb = fr_value_box_list_next(in, fr_value_box_list_head(in));
 
                if (!digest_vb || fr_type_is_null(digest_vb->type)) {
                        REDEBUG("Missing digest argument");
                        return XLAT_ACTION_FAIL;
                }
 
                /*
                 *      Second arg...
                 */
                md_name = digest_vb->vb_strvalue;
        }
        md = EVP_get_digestbyname(md_name);
        if (!md) {
                REDEBUG("Specified digest \"%s\" is not a valid digest type", md_name);
                return XLAT_ACTION_FAIL;
        }
 
        md_len = EVP_MD_size(md);
        MEM(vb = fr_value_box_alloc_null(ctx));
        MEM(fr_value_box_mem_alloc(vb, &digest, vb, NULL, md_len, false) == 0);
 
        if (X509_digest(inst->rsa->x509_certificate_file, md, digest, (unsigned int *)&md_len) != 1) {
                fr_tls_log(request, "Failed calculating certificate fingerprint");
                talloc_free(vb);
                return XLAT_ACTION_FAIL;
        }
 
        fr_dcursor_append(out, vb);
 
        return XLAT_ACTION_DONE;
}
 
/** Return the serial of the public certificate
 *
@verbatim
%<inst>.certificate(serial)
@endverbatim
 *
 * @ingroup xlat_functions
 */
static xlat_action_t cipher_serial_xlat(TALLOC_CTX *ctx, fr_dcursor_t *out,
                                        xlat_ctx_t const *xctx,
                                        request_t *request, UNUSED fr_value_box_list_t *in)
{
        rlm_cipher_t const      *inst = talloc_get_type_abort_const(xctx->mctx->mi->data, rlm_cipher_t);
        ASN1_INTEGER const      *serial;
        fr_value_box_t          *vb;
 
        serial = X509_get0_serialNumber(inst->rsa->x509_certificate_file);
        if (!serial) {
                fr_tls_log(request, "Failed retrieving certificate serial");
                return XLAT_ACTION_FAIL;
        }
 
        MEM(vb = fr_value_box_alloc_null(ctx));
        MEM(fr_value_box_memdup(vb, vb, NULL, serial->data, serial->length, true) == 0);
 
        fr_dcursor_append(out, vb);
 
        return XLAT_ACTION_DONE;
}
 
static xlat_action_t cipher_certificate_xlat(TALLOC_CTX *ctx, fr_dcursor_t *out,
                                             xlat_ctx_t const *xctx,
                                             request_t *request, fr_value_box_list_t *in)
{
        rlm_cipher_t const      *inst = talloc_get_type_abort_const(xctx->mctx->mi->data, rlm_cipher_t);
        char const              *attribute = fr_value_box_list_head(in)->vb_strvalue;
        fr_value_box_t          *vb;
 
        switch (fr_table_value_by_str(cert_attributes, attribute, CIPHER_CERT_ATTR_UNKNOWN)) {
        default:
                REDEBUG("Unknown certificate attribute \"%s\"", attribute);
                return XLAT_ACTION_FAIL;
 
        case CIPHER_CERT_ATTR_FINGERPRINT:
                return cipher_fingerprint_xlat(ctx, out, xctx, request, in);
 
        case CIPHER_CERT_ATTR_SERIAL:
                return cipher_serial_xlat(ctx, out, xctx, request, in);
 
        case CIPHER_CERT_ATTR_NOT_BEFORE:
                MEM(vb = fr_value_box_alloc(ctx, FR_TYPE_DATE, NULL));
                vb->vb_date = inst->rsa->not_before;
                vb->tainted = true;
                fr_dcursor_append(out, vb);
                return XLAT_ACTION_DONE;
 
        case CIPHER_CERT_ATTR_NOT_AFTER:
                MEM(vb = fr_value_box_alloc(ctx, FR_TYPE_DATE, NULL));
                vb->vb_date = inst->rsa->not_after;
                vb->tainted = true;
                fr_dcursor_append(out, vb);
                return XLAT_ACTION_DONE;
        }
}
 
/** Talloc destructor for freeing an EVP_PKEY_CTX
 *
 * @param[in] evp_pkey_ctx      to free.
 * @return 0
 */
static int _evp_pkey_ctx_free(EVP_PKEY_CTX *evp_pkey_ctx)
{
        EVP_PKEY_CTX_free(evp_pkey_ctx);
 
        return 0;
}
 
/** Talloc destructor for freeing an EVP_MD_CTX
 *
 * @param[in] evp_md_ctx        to free.
 * @return 0
 */
static int _evp_md_ctx_free(EVP_MD_CTX *evp_md_ctx)
{
        EVP_MD_CTX_destroy(evp_md_ctx);
 
        return 0;
}
 
static int cipher_rsa_padding_params_set(EVP_PKEY_CTX *evp_pkey_ctx, cipher_rsa_t const *rsa_inst)
{
        if (unlikely(EVP_PKEY_CTX_set_rsa_padding(evp_pkey_ctx, rsa_inst->padding)) <= 0) {
                fr_tls_strerror_printf(NULL);
                PERROR("%s: Failed setting RSA padding type", __FUNCTION__);
                return -1;
        }
 
        switch (rsa_inst->padding) {
        case RSA_NO_PADDING:
        case RSA_X931_PADDING:
        case RSA_PKCS1_PADDING:
                return 0;
 
        /*
         *      Configure OAEP advanced padding options
         */
        case RSA_PKCS1_OAEP_PADDING:
                if (unlikely(EVP_PKEY_CTX_set_rsa_oaep_md(evp_pkey_ctx, rsa_inst->oaep->oaep_digest) <= 0)) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed setting OAEP digest", __FUNCTION__);
                        return -1;
                }
 
                if (unlikely(EVP_PKEY_CTX_set_rsa_mgf1_md(evp_pkey_ctx, rsa_inst->oaep->mgf1_digest) <= 0)) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed setting MGF1 digest", __FUNCTION__);
                        return -1;
                }
 
                if (rsa_inst->oaep->label) {
                        char    *label;
                        size_t  label_len = talloc_strlen(rsa_inst->oaep->label);
 
                        /*
                         *      OpenSSL does not duplicate the label when
                         *      EVP_PKEY_CTX_set0_rsa_oaep_label is called,
                         *      but happily frees it on subsequent calls
                         *      or when the EVP_PKEY_CTX is freed,
                         *      idiots...
                         */
                        MEM(label = talloc_bstrndup(evp_pkey_ctx, rsa_inst->oaep->label, label_len));
                        if (unlikely(EVP_PKEY_CTX_set0_rsa_oaep_label(evp_pkey_ctx, label, label_len) <= 0)) {
                                fr_tls_strerror_printf(NULL);
                                PERROR("%s: Failed setting OAEP padding label", __FUNCTION__);
                                OPENSSL_free(label);
                                return -1;
                        }
                }
                return 0;
 
        default:
                fr_assert(0);
                return -1;
        }
}
 
/** Pre-initialises the EVP_PKEY_CTX necessary for performing RSA encryption/decryption/sign/verify
 *
 * If reference counting is used for EVP_PKEY structs, should also prevent any mutex contention
 * associated with incrementing/decrementing those references.
 *
 * xlat functions MUST NOT interleave PKEY operations with yields
 *
 * @return 0.
 */
static int cipher_rsa_thread_instantiate(module_thread_inst_ctx_t const *mctx)
{
        rlm_cipher_t const              *inst = talloc_get_type_abort(mctx->mi->data, rlm_cipher_t);
        rlm_cipher_rsa_thread_inst_t    *ti = talloc_get_type_abort(mctx->thread, rlm_cipher_rsa_thread_inst_t);
 
        /*
         *      Pre-allocate different contexts for the different operations
         *      The OpenSSL docs say this is fine, and it reduces the potential
         *      for SEGVs and other random errors due to trying to change the
         *      configuration of a context multiple times.
         */
        if (inst->rsa->certificate_file) {
                /*
                 *      Alloc encrypt
                 */
                ti->evp_encrypt_ctx = EVP_PKEY_CTX_new(inst->rsa->certificate_file, NULL);
                if (!ti->evp_encrypt_ctx) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed allocating encrypt EVP_PKEY_CTX", __FUNCTION__);
                        return -1;
                }
                talloc_set_type(ti->evp_encrypt_ctx, EVP_PKEY_CTX);
                ti->evp_encrypt_ctx = talloc_steal(ti, ti->evp_encrypt_ctx);    /* Bind lifetime to instance */
                talloc_set_destructor(ti->evp_encrypt_ctx, _evp_pkey_ctx_free); /* Free ctx correctly on chunk free */
 
                /*
                 *      Configure encrypt
                 */
                if (unlikely(EVP_PKEY_encrypt_init(ti->evp_encrypt_ctx) <= 0)) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed initialising encrypt EVP_PKEY_CTX", __FUNCTION__);
                        return -1;
                }
                if (unlikely(cipher_rsa_padding_params_set(ti->evp_encrypt_ctx, inst->rsa) < 0)) {
                        ERROR("%s: Failed setting padding for encrypt EVP_PKEY_CTX", __FUNCTION__);
                        return -1;
                }
 
                /*
                 *      Alloc verify
                 */
                ti->evp_verify_ctx = EVP_PKEY_CTX_new(inst->rsa->certificate_file, NULL);
                if (!ti->evp_verify_ctx) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed allocating verify EVP_PKEY_CTX", __FUNCTION__);
                        return -1;
                }
                talloc_set_type(ti->evp_verify_ctx, EVP_PKEY_CTX);
                ti->evp_verify_ctx = talloc_steal(ti, ti->evp_verify_ctx);      /* Bind lifetime to instance */
                talloc_set_destructor(ti->evp_verify_ctx, _evp_pkey_ctx_free);  /* Free ctx correctly on chunk free */
 
                /*
                 *      Configure verify
                 */
                if (unlikely(EVP_PKEY_verify_init(ti->evp_verify_ctx) <= 0)) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed initialising verify EVP_PKEY_CTX", __FUNCTION__);
                        return -1;
                }
 
                /*
                 *      OAEP not valid for signing or verification
                 */
                if (inst->rsa->padding != RSA_PKCS1_OAEP_PADDING) {
                        if (unlikely(cipher_rsa_padding_params_set(ti->evp_verify_ctx, inst->rsa) < 0)) {
                                ERROR("%s: Failed setting padding for verify EVP_PKEY_CTX", __FUNCTION__);
                                return -1;
                        }
                }
 
                if (unlikely(EVP_PKEY_CTX_set_signature_md(ti->evp_verify_ctx, inst->rsa->sig_digest)) <= 0) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed setting signature digest type", __FUNCTION__);
                        return -1;
                }
        }
 
        if (inst->rsa->private_key_file) {
                /*
                 *      Alloc decrypt
                 */
                ti->evp_decrypt_ctx = EVP_PKEY_CTX_new(inst->rsa->private_key_file, NULL);
                if (!ti->evp_decrypt_ctx) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed allocating decrypt EVP_PKEY_CTX", __FUNCTION__);
                        return -1;
                }
                talloc_set_type(ti->evp_decrypt_ctx, EVP_PKEY_CTX);
                ti->evp_decrypt_ctx = talloc_steal(ti, ti->evp_decrypt_ctx);    /* Bind lifetime to instance */
                talloc_set_destructor(ti->evp_decrypt_ctx, _evp_pkey_ctx_free); /* Free ctx correctly on chunk free */
 
                /*
                 *      Configure decrypt
                 */
                if (unlikely(EVP_PKEY_decrypt_init(ti->evp_decrypt_ctx) <= 0)) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed initialising decrypt EVP_PKEY_CTX", __FUNCTION__);
                        return -1;
                }
                if (unlikely(cipher_rsa_padding_params_set(ti->evp_decrypt_ctx, inst->rsa) < 0)) {
                        ERROR("%s: Failed setting padding for decrypt EVP_PKEY_CTX", __FUNCTION__);
                        return -1;
                }
 
                /*
                 *      Alloc sign
                 */
                ti->evp_sign_ctx = EVP_PKEY_CTX_new(inst->rsa->private_key_file, NULL);
                if (!ti->evp_sign_ctx) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed allocating sign EVP_PKEY_CTX", __FUNCTION__);
                        return -1;
                }
                talloc_set_type(ti->evp_sign_ctx, EVP_PKEY_CTX);
                ti->evp_sign_ctx = talloc_steal(ti, ti->evp_sign_ctx);          /* Bind lifetime to instance */
                talloc_set_destructor(ti->evp_sign_ctx, _evp_pkey_ctx_free);    /* Free ctx correctly on chunk free */
 
                /*
                 *      Configure sign
                 */
                if (unlikely(EVP_PKEY_sign_init(ti->evp_sign_ctx) <= 0)) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed initialising sign EVP_PKEY_CTX", __FUNCTION__);
                        return -1;
                }
 
                /*
                 *      OAEP not valid for signing or verification
                 */
                if (inst->rsa->padding != RSA_PKCS1_OAEP_PADDING) {
                        if (unlikely(cipher_rsa_padding_params_set(ti->evp_sign_ctx, inst->rsa) < 0)) {
                                ERROR("%s: Failed setting padding for sign EVP_PKEY_CTX", __FUNCTION__);
                                return -1;
                        }
                }
 
                if (unlikely(EVP_PKEY_CTX_set_signature_md(ti->evp_sign_ctx, inst->rsa->sig_digest)) <= 0) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed setting signature digest type", __FUNCTION__);
                        return -1;
                }
 
                /*
                 *      Alloc digest ctx for signing and verification
                 */
                ti->evp_md_ctx = EVP_MD_CTX_create();
                if (!ti->evp_md_ctx) {
                        fr_tls_strerror_printf(NULL);
                        PERROR("%s: Failed allocating EVP_MD_CTX", __FUNCTION__);
                        return -1;
                }
                talloc_set_type(ti->evp_md_ctx, EVP_MD_CTX);
                ti->evp_md_ctx = talloc_steal(ti, ti->evp_md_ctx);                      /* Bind lifetime to instance */
                talloc_set_destructor(ti->evp_md_ctx, _evp_md_ctx_free);                /* Free ctx correctly on chunk free */
                MEM(ti->digest_buff = talloc_array(ti, uint8_t, EVP_MD_size(inst->rsa->sig_digest)));
        }
 
        return 0;
}
 
static int mod_thread_instantiate(module_thread_inst_ctx_t const *mctx)
{
        rlm_cipher_t    *inst = talloc_get_type_abort(mctx->mi->data, rlm_cipher_t);
 
        switch (inst->type) {
        case RLM_CIPHER_TYPE_RSA:
                talloc_set_type(mctx->thread, rlm_cipher_rsa_thread_inst_t);
                return cipher_rsa_thread_instantiate(mctx);
 
        case RLM_CIPHER_TYPE_SYMMETRIC:
        case RLM_CIPHER_TYPE_INVALID:
                fr_assert(0);
        }
 
        return 0;
}
 
/*
 *      Do any per-module initialization that is separate to each
 *      configured instance of the module.  e.g. set up connections
 *      to external databases, read configuration files, set up
 *      dictionary entries, etc.
 */
static int mod_bootstrap(module_inst_ctx_t const *mctx)
{
        rlm_cipher_t const      *inst = talloc_get_type_abort(mctx->mi->data, rlm_cipher_t);
        CONF_SECTION            *conf = mctx->mi->conf;
 
        switch (inst->type) {
        case RLM_CIPHER_TYPE_RSA:
                if (!inst->rsa) {
                        cf_log_err(conf, "type = rsa, but no 'rsa { ... }' configuration section provided");
                        return -1;
                }
 
                if (!inst->rsa->private_key_file && !inst->rsa->certificate_file) {
                        cf_log_err(conf, "type = rsa, but neither "
                                         "'private_key_file' nor 'certificate_file' configured");
                        return -1;
                }
 
                if (inst->rsa->private_key_file) {
                        xlat_t *xlat;
 
                        /*
                         *      Register decrypt xlat
                         */
                        xlat = module_rlm_xlat_register(mctx->mi->boot, mctx, "decrypt", cipher_rsa_decrypt_xlat, FR_TYPE_STRING);
                        xlat_func_args_set(xlat, cipher_rsa_decrypt_xlat_arg);
 
                        /*
                         *      Verify sign xlat
                         */
                        xlat = module_rlm_xlat_register(mctx->mi->boot, mctx, "verify", cipher_rsa_verify_xlat, FR_TYPE_BOOL);
                        xlat_func_args_set(xlat, cipher_rsa_verify_xlat_arg);
                }
 
                if (inst->rsa->certificate_file) {
                        xlat_t *xlat;
 
                        /*
                         *      If we have both public and private keys check they're
                         *      part of the same keypair.  This isn't technically a requirement
                         *      but it fixes some obscure errors where the user uses the serial
                         *      xlat, expecting it to be the serial of the keypair containing
                         *      the private key.
                         */
                        if (inst->rsa->private_key_file && inst->rsa->x509_certificate_file) {
                                if (X509_check_private_key(inst->rsa->x509_certificate_file,
                                                           inst->rsa->private_key_file) == 0) {
                                        fr_tls_strerror_printf(NULL);
                                        cf_log_perr(conf, "Private key does not match the certificate public key");
                                        return -1;
                                }
                        }
 
                        /*
                         *      Register encrypt xlat
                         */
                        xlat = module_rlm_xlat_register(mctx->mi->boot, mctx, "encrypt", cipher_rsa_encrypt_xlat, FR_TYPE_OCTETS);
                        xlat_func_args_set(xlat, cipher_rsa_encrypt_xlat_arg);
 
                        /*
                         *      Register sign xlat
                         */
                        xlat = module_rlm_xlat_register(mctx->mi->boot, mctx, "sign", cipher_rsa_sign_xlat, FR_TYPE_OCTETS);
                        xlat_func_args_set(xlat, cipher_rsa_sign_xlat_arg);
 
                        /*
                         *      FIXME: These should probably be split into separate xlats
                         *      so we can optimise for return types.
                         */
                        xlat = module_rlm_xlat_register(mctx->mi->boot, mctx, "certificate", cipher_certificate_xlat, FR_TYPE_VOID);
                        xlat_func_args_set(xlat, cipher_certificate_xlat_args);
                }
                break;
 
        /*
         *      Populated by cipher_type_parse() so if
         *      the value is unrecognised we've got an issue.
         */
        default:
                fr_assert(0);
                return -1;
        }
 
        return 0;
}
 
/*
 *      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_cipher;
module_rlm_t rlm_cipher = {
        .common = {
                .magic                  = MODULE_MAGIC_INIT,
                .name                   = "cipher",
                .inst_size              = sizeof(rlm_cipher_t),
                .thread_inst_size       = sizeof(rlm_cipher_rsa_thread_inst_t),
                .config                 = module_config,
                .bootstrap              = mod_bootstrap,
                .thread_instantiate     = mod_thread_instantiate
        }
};