/**

 * \file pkcs5.c

 *

 * \brief PKCS#5 functions

 *

 * \author Mathias Olsson <mathias@kompetensum.com>

 *

 *  Copyright The Mbed TLS Contributors

 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later

 */

/*

 * PKCS#5 includes PBKDF2 and more

 *

 * http://tools.ietf.org/html/rfc2898 (Specification)

 * http://tools.ietf.org/html/rfc6070 (Test vectors)

 */

#include "common.h"

#if defined(MBEDTLS_PKCS5_C)

#include "mbedtls/pkcs5.h"

#include "mbedtls/error.h"

#if defined(MBEDTLS_ASN1_PARSE_C)

#include "mbedtls/asn1.h"

#if defined(MBEDTLS_CIPHER_C)

#include "mbedtls/cipher.h"

#endif /* MBEDTLS_CIPHER_C */

#include "mbedtls/oid.h"

#endif /* MBEDTLS_ASN1_PARSE_C */

#include <string.h>

#include "mbedtls/platform.h"

#include "psa_util_internal.h"

#if defined(MBEDTLS_ASN1_PARSE_C) && defined(MBEDTLS_CIPHER_C)

static int pkcs5_parse_pbkdf2_params(const mbedtls_asn1_buf *params,

                                     mbedtls_asn1_buf *salt, int *iterations,

                                     int *keylen, mbedtls_md_type_t *md_type)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    mbedtls_asn1_buf prf_alg_oid;

    unsigned char *p = params->p;

    const unsigned char *end = params->p + params->len;

    if (params->tag != (MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT,

                                 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);

    }

    /*

     *  PBKDF2-params ::= SEQUENCE {

     *    salt              OCTET STRING,

     *    iterationCount    INTEGER,

     *    keyLength         INTEGER OPTIONAL

     *    prf               AlgorithmIdentifier DEFAULT algid-hmacWithSHA1

     *  }

     *

     */

    if ((ret = mbedtls_asn1_get_tag(&p, end, &salt->len,

                                    MBEDTLS_ASN1_OCTET_STRING)) != 0) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);

    }

    salt->p = p;

    p += salt->len;

    if ((ret = mbedtls_asn1_get_int(&p, end, iterations)) != 0) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);

    }

    if (p == end) {

        return 0;

    }

    if ((ret = mbedtls_asn1_get_int(&p, end, keylen)) != 0) {

        if (ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {

            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);

        }

    }

    if (p == end) {

        return 0;

    }

    if ((ret = mbedtls_asn1_get_alg_null(&p, end, &prf_alg_oid)) != 0) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);

    }

    if (mbedtls_oid_get_md_hmac(&prf_alg_oid, md_type) != 0) {

        return MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE;

    }

    if (p != end) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT,

                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);

    }

    return 0;

}

#if !defined(MBEDTLS_CIPHER_PADDING_PKCS7)

int mbedtls_pkcs5_pbes2_ext(const mbedtls_asn1_buf *pbe_params, int mode,

                            const unsigned char *pwd,  size_t pwdlen,

                            const unsigned char *data, size_t datalen,

                            unsigned char *output, size_t output_size,

                            size_t *output_len);

#endif

#if !defined(MBEDTLS_DEPRECATED_REMOVED)

int mbedtls_pkcs5_pbes2(const mbedtls_asn1_buf *pbe_params, int mode,

                        const unsigned char *pwd,  size_t pwdlen,

                        const unsigned char *data, size_t datalen,

                        unsigned char *output)

{

    size_t output_len = 0;

    /* We assume caller of the function is providing a big enough output buffer

     * so we pass output_size as SIZE_MAX to pass checks, However, no guarantees

     * for the output size actually being correct.

     */

    return mbedtls_pkcs5_pbes2_ext(pbe_params, mode, pwd, pwdlen, data,

                                   datalen, output, SIZE_MAX, &output_len);

}

#endif

int mbedtls_pkcs5_pbes2_ext(const mbedtls_asn1_buf *pbe_params, int mode,

                            const unsigned char *pwd,  size_t pwdlen,

                            const unsigned char *data, size_t datalen,

                            unsigned char *output, size_t output_size,

                            size_t *output_len)

{

    int ret, iterations = 0, keylen = 0;

    unsigned char *p, *end;

    mbedtls_asn1_buf kdf_alg_oid, enc_scheme_oid, kdf_alg_params, enc_scheme_params;

    mbedtls_asn1_buf salt;

    mbedtls_md_type_t md_type = MBEDTLS_MD_SHA1;

    unsigned char key[32], iv[32];

    const mbedtls_cipher_info_t *cipher_info;

    mbedtls_cipher_type_t cipher_alg;

    mbedtls_cipher_context_t cipher_ctx;

    unsigned int padlen = 0;

    p = pbe_params->p;

    end = p + pbe_params->len;

    /*

     *  PBES2-params ::= SEQUENCE {

     *    keyDerivationFunc AlgorithmIdentifier {{PBES2-KDFs}},

     *    encryptionScheme AlgorithmIdentifier {{PBES2-Encs}}

     *  }

     */

    if (pbe_params->tag != (MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT,

                                 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);

    }

    if ((ret = mbedtls_asn1_get_alg(&p, end, &kdf_alg_oid,

                                    &kdf_alg_params)) != 0) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);

    }

    // Only PBKDF2 supported at the moment

    //

    if (MBEDTLS_OID_CMP(MBEDTLS_OID_PKCS5_PBKDF2, &kdf_alg_oid) != 0) {

        return MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE;

    }

    if ((ret = pkcs5_parse_pbkdf2_params(&kdf_alg_params,

                                         &salt, &iterations, &keylen,

                                         &md_type)) != 0) {

        return ret;

    }

    if ((ret = mbedtls_asn1_get_alg(&p, end, &enc_scheme_oid,

                                    &enc_scheme_params)) != 0) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS5_INVALID_FORMAT, ret);

    }

    if (mbedtls_oid_get_cipher_alg(&enc_scheme_oid, &cipher_alg) != 0) {

        return MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE;

    }

    cipher_info = mbedtls_cipher_info_from_type(cipher_alg);

    if (cipher_info == NULL) {

        return MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE;

    }

    /*

     * The value of keylen from pkcs5_parse_pbkdf2_params() is ignored

     * since it is optional and we don't know if it was set or not

     */

    keylen = (int) mbedtls_cipher_info_get_key_bitlen(cipher_info) / 8;

    if (enc_scheme_params.tag != MBEDTLS_ASN1_OCTET_STRING ||

        enc_scheme_params.len != mbedtls_cipher_info_get_iv_size(cipher_info)) {

        return MBEDTLS_ERR_PKCS5_INVALID_FORMAT;

    }

    if (mode == MBEDTLS_PKCS5_DECRYPT) {

        if (output_size < datalen) {

            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;

        }

    }

    if (mode == MBEDTLS_PKCS5_ENCRYPT) {

        padlen = cipher_info->block_size - (datalen % cipher_info->block_size);

        if (output_size < (datalen + padlen)) {

            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;

        }

    }

    mbedtls_cipher_init(&cipher_ctx);

    memcpy(iv, enc_scheme_params.p, enc_scheme_params.len);

    if ((ret = mbedtls_pkcs5_pbkdf2_hmac_ext(md_type, pwd, pwdlen, salt.p,

                                             salt.len, iterations, keylen,

                                             key)) != 0) {

        goto exit;

    }

    if ((ret = mbedtls_cipher_setup(&cipher_ctx, cipher_info)) != 0) {

        goto exit;

    }

    if ((ret = mbedtls_cipher_setkey(&cipher_ctx, key, 8 * keylen,

                                     (mbedtls_operation_t) mode)) != 0) {

        goto exit;

    }

#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)

    {

        /* PKCS5 uses CBC with PKCS7 padding (which is the same as

         * "PKCS5 padding" except that it's typically only called PKCS5

         * with 64-bit-block ciphers).

         */

        mbedtls_cipher_padding_t padding = MBEDTLS_PADDING_PKCS7;

#if !defined(MBEDTLS_CIPHER_PADDING_PKCS7)

        /* For historical reasons, when decrypting, this function works when

         * decrypting even when support for PKCS7 padding is disabled. In this

         * case, it ignores the padding, and so will never report a

         * password mismatch.

         */

        if (mode == MBEDTLS_DECRYPT) {

            padding = MBEDTLS_PADDING_NONE;

        }

#endif

        if ((ret = mbedtls_cipher_set_padding_mode(&cipher_ctx, padding)) != 0) {

            goto exit;

        }

    }

#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */

    if ((ret = mbedtls_cipher_crypt(&cipher_ctx, iv, enc_scheme_params.len,

                                    data, datalen, output, output_len)) != 0) {

        ret = MBEDTLS_ERR_PKCS5_PASSWORD_MISMATCH;

    }

exit:

    mbedtls_cipher_free(&cipher_ctx);

    return ret;

}

#endif /* MBEDTLS_ASN1_PARSE_C && MBEDTLS_CIPHER_C */

static int pkcs5_pbkdf2_hmac(mbedtls_md_context_t *ctx,

                             const unsigned char *password,

                             size_t plen, const unsigned char *salt, size_t slen,

                             unsigned int iteration_count,

                             uint32_t key_length, unsigned char *output)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    unsigned int i;

    unsigned char md1[MBEDTLS_MD_MAX_SIZE];

    unsigned char work[MBEDTLS_MD_MAX_SIZE];

    unsigned char md_size = mbedtls_md_get_size(ctx->md_info);

    size_t use_len;

    unsigned char *out_p = output;

    unsigned char counter[4];

    memset(counter, 0, 4);

    counter[3] = 1;

#if UINT_MAX > 0xFFFFFFFF

    if (iteration_count > 0xFFFFFFFF) {

        return MBEDTLS_ERR_PKCS5_BAD_INPUT_DATA;

    }

#endif

    if ((ret = mbedtls_md_hmac_starts(ctx, password, plen)) != 0) {

        return ret;

    }

    while (key_length) {

        // U1 ends up in work

        //

        if ((ret = mbedtls_md_hmac_update(ctx, salt, slen)) != 0) {

            goto cleanup;

        }

        if ((ret = mbedtls_md_hmac_update(ctx, counter, 4)) != 0) {

            goto cleanup;

        }

        if ((ret = mbedtls_md_hmac_finish(ctx, work)) != 0) {

            goto cleanup;

        }

        if ((ret = mbedtls_md_hmac_reset(ctx)) != 0) {

            goto cleanup;

        }

        memcpy(md1, work, md_size);

        for (i = 1; i < iteration_count; i++) {

            // U2 ends up in md1

            //

            if ((ret = mbedtls_md_hmac_update(ctx, md1, md_size)) != 0) {

                goto cleanup;

            }

            if ((ret = mbedtls_md_hmac_finish(ctx, md1)) != 0) {

                goto cleanup;

            }

            if ((ret = mbedtls_md_hmac_reset(ctx)) != 0) {

                goto cleanup;

            }

            // U1 xor U2

            //

            mbedtls_xor(work, work, md1, md_size);

        }

        use_len = (key_length < md_size) ? key_length : md_size;

        memcpy(out_p, work, use_len);

        key_length -= (uint32_t) use_len;

        out_p += use_len;

        for (i = 4; i > 0; i--) {

            if (++counter[i - 1] != 0) {

                break;

            }

        }

    }

cleanup:

    /* Zeroise buffers to clear sensitive data from memory. */

    mbedtls_platform_zeroize(work, MBEDTLS_MD_MAX_SIZE);

    mbedtls_platform_zeroize(md1, MBEDTLS_MD_MAX_SIZE);

    return ret;

}

#if !defined(MBEDTLS_DEPRECATED_REMOVED)

int mbedtls_pkcs5_pbkdf2_hmac(mbedtls_md_context_t *ctx,

                              const unsigned char *password,

                              size_t plen, const unsigned char *salt, size_t slen,

                              unsigned int iteration_count,

                              uint32_t key_length, unsigned char *output)

{

    return pkcs5_pbkdf2_hmac(ctx, password, plen, salt, slen, iteration_count,

                             key_length, output);

}

#endif

int mbedtls_pkcs5_pbkdf2_hmac_ext(mbedtls_md_type_t md_alg,

                                  const unsigned char *password,

                                  size_t plen, const unsigned char *salt, size_t slen,

                                  unsigned int iteration_count,

                                  uint32_t key_length, unsigned char *output)

{

    mbedtls_md_context_t md_ctx;

    const mbedtls_md_info_t *md_info = NULL;

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    md_info = mbedtls_md_info_from_type(md_alg);

    if (md_info == NULL) {

        return MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE;

    }

    mbedtls_md_init(&md_ctx);

    if ((ret = mbedtls_md_setup(&md_ctx, md_info, 1)) != 0) {

        goto exit;

    }

    ret = pkcs5_pbkdf2_hmac(&md_ctx, password, plen, salt, slen,

                            iteration_count, key_length, output);

exit:

    mbedtls_md_free(&md_ctx);

    return ret;

}

#if defined(MBEDTLS_SELF_TEST)

#if !defined(MBEDTLS_MD_CAN_SHA1)

int mbedtls_pkcs5_self_test(int verbose)

{

    if (verbose != 0) {

        mbedtls_printf("  PBKDF2 (SHA1): skipped\n\n");

    }

    return 0;

}

#else

#define MAX_TESTS   6

static const size_t plen_test_data[MAX_TESTS] =

{ 8, 8, 8, 24, 9 };

static const unsigned char password_test_data[MAX_TESTS][32] =

{

    "password",

    "password",

    "password",

    "passwordPASSWORDpassword",

    "pass\0word",

};

static const size_t slen_test_data[MAX_TESTS] =

{ 4, 4, 4, 36, 5 };

static const unsigned char salt_test_data[MAX_TESTS][40] =

{

    "salt",

    "salt",

    "salt",

    "saltSALTsaltSALTsaltSALTsaltSALTsalt",

    "sa\0lt",

};

static const uint32_t it_cnt_test_data[MAX_TESTS] =

{ 1, 2, 4096, 4096, 4096 };

static const uint32_t key_len_test_data[MAX_TESTS] =

{ 20, 20, 20, 25, 16 };

static const unsigned char result_key_test_data[MAX_TESTS][32] =

{

    { 0x0c, 0x60, 0xc8, 0x0f, 0x96, 0x1f, 0x0e, 0x71,

      0xf3, 0xa9, 0xb5, 0x24, 0xaf, 0x60, 0x12, 0x06,

      0x2f, 0xe0, 0x37, 0xa6 },

    { 0xea, 0x6c, 0x01, 0x4d, 0xc7, 0x2d, 0x6f, 0x8c,

      0xcd, 0x1e, 0xd9, 0x2a, 0xce, 0x1d, 0x41, 0xf0,

      0xd8, 0xde, 0x89, 0x57 },

    { 0x4b, 0x00, 0x79, 0x01, 0xb7, 0x65, 0x48, 0x9a,

      0xbe, 0xad, 0x49, 0xd9, 0x26, 0xf7, 0x21, 0xd0,

      0x65, 0xa4, 0x29, 0xc1 },

    { 0x3d, 0x2e, 0xec, 0x4f, 0xe4, 0x1c, 0x84, 0x9b,

      0x80, 0xc8, 0xd8, 0x36, 0x62, 0xc0, 0xe4, 0x4a,

      0x8b, 0x29, 0x1a, 0x96, 0x4c, 0xf2, 0xf0, 0x70,

      0x38 },

    { 0x56, 0xfa, 0x6a, 0xa7, 0x55, 0x48, 0x09, 0x9d,

      0xcc, 0x37, 0xd7, 0xf0, 0x34, 0x25, 0xe0, 0xc3 },

};

int mbedtls_pkcs5_self_test(int verbose)

{

    int ret, i;

    unsigned char key[64];

    for (i = 0; i < MAX_TESTS; i++) {

        if (verbose != 0) {

            mbedtls_printf("  PBKDF2 (SHA1) #%d: ", i);

        }

        ret = mbedtls_pkcs5_pbkdf2_hmac_ext(MBEDTLS_MD_SHA1, password_test_data[i],

                                            plen_test_data[i], salt_test_data[i],

                                            slen_test_data[i], it_cnt_test_data[i],

                                            key_len_test_data[i], key);

        if (ret != 0 ||

            memcmp(result_key_test_data[i], key, key_len_test_data[i]) != 0) {

            if (verbose != 0) {

                mbedtls_printf("failed\n");

            }

            ret = 1;

            goto exit;

        }

        if (verbose != 0) {

            mbedtls_printf("passed\n");

        }

    }

    if (verbose != 0) {

        mbedtls_printf("\n");

    }

exit:

    return ret;

}

#endif /* MBEDTLS_MD_CAN_SHA1 */

#endif /* MBEDTLS_SELF_TEST */

#endif /* MBEDTLS_PKCS5_C */