/*

 *  PKCS#12 Personal Information Exchange Syntax

 *

 *  Copyright The Mbed TLS Contributors

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

 */

/*

 *  The PKCS #12 Personal Information Exchange Syntax Standard v1.1

 *

 *  http://www.rsa.com/rsalabs/pkcs/files/h11301-wp-pkcs-12v1-1-personal-information-exchange-syntax.pdf

 *  ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-12/pkcs-12v1-1.asn

 */

#include "common.h"

#if defined(MBEDTLS_PKCS12_C)

#include "mbedtls/pkcs12.h"

#include "mbedtls/asn1.h"

#include "mbedtls/cipher.h"

#include "mbedtls/platform_util.h"

#include "mbedtls/error.h"

#include <string.h>

#if defined(MBEDTLS_ARC4_C)

#include "mbedtls/arc4.h"

#endif

#if defined(MBEDTLS_DES_C)

#include "mbedtls/des.h"

#endif

#if defined(MBEDTLS_ASN1_PARSE_C)

static int pkcs12_parse_pbe_params(mbedtls_asn1_buf *params,

                                   mbedtls_asn1_buf *salt, int *iterations)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    unsigned char **p = &params->p;

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

    /*

     *  pkcs-12PbeParams ::= SEQUENCE {

     *    salt          OCTET STRING,

     *    iterations    INTEGER

     *  }

     *

     */

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

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT,

                                 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);

    }

    if ((ret = mbedtls_asn1_get_tag(p, end, &salt->len, MBEDTLS_ASN1_OCTET_STRING)) != 0) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS12_PBE_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_PKCS12_PBE_INVALID_FORMAT, ret);

    }

    if (*p != end) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_PKCS12_PBE_INVALID_FORMAT,

                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);

    }

    return 0;

}

#define PKCS12_MAX_PWDLEN 128

static int pkcs12_pbe_derive_key_iv(mbedtls_asn1_buf *pbe_params, mbedtls_md_type_t md_type,

                                    const unsigned char *pwd,  size_t pwdlen,

                                    unsigned char *key, size_t keylen,

                                    unsigned char *iv,  size_t ivlen)

{

    int ret, iterations = 0;

    mbedtls_asn1_buf salt;

    size_t i;

    unsigned char unipwd[PKCS12_MAX_PWDLEN * 2 + 2];

    if (pwdlen > PKCS12_MAX_PWDLEN) {

        return MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA;

    }

    memset(&salt, 0, sizeof(mbedtls_asn1_buf));

    memset(&unipwd, 0, sizeof(unipwd));

    if ((ret = pkcs12_parse_pbe_params(pbe_params, &salt,

                                       &iterations)) != 0) {

        return ret;

    }

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

        unipwd[i * 2 + 1] = pwd[i];

    }

    if ((ret = mbedtls_pkcs12_derivation(key, keylen, unipwd, pwdlen * 2 + 2,

                                         salt.p, salt.len, md_type,

                                         MBEDTLS_PKCS12_DERIVE_KEY, iterations)) != 0) {

        return ret;

    }

    if (iv == NULL || ivlen == 0) {

        return 0;

    }

    if ((ret = mbedtls_pkcs12_derivation(iv, ivlen, unipwd, pwdlen * 2 + 2,

                                         salt.p, salt.len, md_type,

                                         MBEDTLS_PKCS12_DERIVE_IV, iterations)) != 0) {

        return ret;

    }

    return 0;

}

#undef PKCS12_MAX_PWDLEN

int mbedtls_pkcs12_pbe_sha1_rc4_128(mbedtls_asn1_buf *pbe_params, int mode,

                                    const unsigned char *pwd,  size_t pwdlen,

                                    const unsigned char *data, size_t len,

                                    unsigned char *output)

{

#if !defined(MBEDTLS_ARC4_C)

    ((void) pbe_params);

    ((void) mode);

    ((void) pwd);

    ((void) pwdlen);

    ((void) data);

    ((void) len);

    ((void) output);

    return MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE;

#else

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    unsigned char key[16];

    mbedtls_arc4_context ctx;

    ((void) mode);

    mbedtls_arc4_init(&ctx);

    if ((ret = pkcs12_pbe_derive_key_iv(pbe_params, MBEDTLS_MD_SHA1,

                                        pwd, pwdlen,

                                        key, 16, NULL, 0)) != 0) {

        return ret;

    }

    mbedtls_arc4_setup(&ctx, key, 16);

    if ((ret = mbedtls_arc4_crypt(&ctx, len, data, output)) != 0) {

        goto exit;

    }

exit:

    mbedtls_platform_zeroize(key, sizeof(key));

    mbedtls_arc4_free(&ctx);

    return ret;

#endif /* MBEDTLS_ARC4_C */

}

#if !defined(MBEDTLS_CIPHER_PADDING_PKCS7)

int mbedtls_pkcs12_pbe_ext(mbedtls_asn1_buf *pbe_params, int mode,

                           mbedtls_cipher_type_t cipher_type, mbedtls_md_type_t md_type,

                           const unsigned char *pwd,  size_t pwdlen,

                           const unsigned char *data, size_t len,

                           unsigned char *output, size_t output_size,

                           size_t *output_len);

#endif

int mbedtls_pkcs12_pbe(mbedtls_asn1_buf *pbe_params, int mode,

                       mbedtls_cipher_type_t cipher_type, mbedtls_md_type_t md_type,

                       const unsigned char *pwd,  size_t pwdlen,

                       const unsigned char *data, size_t len,

                       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_pkcs12_pbe_ext(pbe_params, mode, cipher_type, md_type,

                                  pwd, pwdlen, data, len, output, SIZE_MAX,

                                  &output_len);

}

int mbedtls_pkcs12_pbe_ext(mbedtls_asn1_buf *pbe_params, int mode,

                           mbedtls_cipher_type_t cipher_type, mbedtls_md_type_t md_type,

                           const unsigned char *pwd,  size_t pwdlen,

                           const unsigned char *data, size_t len,

                           unsigned char *output, size_t output_size,

                           size_t *output_len)

{

    int ret, keylen = 0;

    unsigned char key[32];

    unsigned char iv[16];

    const mbedtls_cipher_info_t *cipher_info;

    mbedtls_cipher_context_t cipher_ctx;

    size_t finish_olen = 0;

    unsigned int padlen = 0;

    if (pwd == NULL && pwdlen != 0) {

        return MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA;

    }

    cipher_info = mbedtls_cipher_info_from_type(cipher_type);

    if (cipher_info == NULL) {

        return MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE;

    }

    keylen = cipher_info->key_bitlen / 8;

    if (mode == MBEDTLS_PKCS12_PBE_DECRYPT) {

        if (output_size < len) {

            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;

        }

    }

    if (mode == MBEDTLS_PKCS12_PBE_ENCRYPT) {

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

        if (output_size < (len + padlen)) {

            return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;

        }

    }

    if ((ret = pkcs12_pbe_derive_key_iv(pbe_params, md_type, pwd, pwdlen,

                                        key, keylen,

                                        iv, cipher_info->iv_size)) != 0) {

        return ret;

    }

    mbedtls_cipher_init(&cipher_ctx);

    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)

    {

        /* PKCS12 uses CBC with PKCS7 padding */

        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_PKCS12_PBE_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_set_iv(&cipher_ctx, iv, cipher_info->iv_size)) != 0) {

        goto exit;

    }

    if ((ret = mbedtls_cipher_reset(&cipher_ctx)) != 0) {

        goto exit;

    }

    if ((ret = mbedtls_cipher_update(&cipher_ctx, data, len,

                                     output, output_len)) != 0) {

        goto exit;

    }

    if ((ret = mbedtls_cipher_finish(&cipher_ctx, output + (*output_len), &finish_olen)) != 0) {

        ret = MBEDTLS_ERR_PKCS12_PASSWORD_MISMATCH;

    }

    *output_len += finish_olen;

exit:

    mbedtls_platform_zeroize(key, sizeof(key));

    mbedtls_platform_zeroize(iv,  sizeof(iv));

    mbedtls_cipher_free(&cipher_ctx);

    return ret;

}

#endif /* MBEDTLS_ASN1_PARSE_C */

static void pkcs12_fill_buffer(unsigned char *data, size_t data_len,

                               const unsigned char *filler, size_t fill_len)

{

    unsigned char *p = data;

    size_t use_len;

    if (filler != NULL && fill_len != 0) {

        while (data_len > 0) {

            use_len = (data_len > fill_len) ? fill_len : data_len;

            memcpy(p, filler, use_len);

            p += use_len;

            data_len -= use_len;

        }

    } else {

        /* If either of the above are not true then clearly there is nothing

         * that this function can do. The function should *not* be called

         * under either of those circumstances, as you could end up with an

         * incorrect output but for safety's sake, leaving the check in as

         * otherwise we could end up with memory corruption.*/

    }

}

int mbedtls_pkcs12_derivation(unsigned char *data, size_t datalen,

                              const unsigned char *pwd, size_t pwdlen,

                              const unsigned char *salt, size_t saltlen,

                              mbedtls_md_type_t md_type, int id, int iterations)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    unsigned int j;

    unsigned char diversifier[128];

    unsigned char salt_block[128], pwd_block[128], hash_block[128];

    unsigned char hash_output[MBEDTLS_MD_MAX_SIZE];

    unsigned char *p;

    unsigned char c;

    int           use_password = 0;

    int           use_salt = 0;

    size_t hlen, use_len, v, i;

    const mbedtls_md_info_t *md_info;

    mbedtls_md_context_t md_ctx;

    // This version only allows max of 64 bytes of password or salt

    if (datalen > 128 || pwdlen > 64 || saltlen > 64) {

        return MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA;

    }

    if (pwd == NULL && pwdlen != 0) {

        return MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA;

    }

    if (salt == NULL && saltlen != 0) {

        return MBEDTLS_ERR_PKCS12_BAD_INPUT_DATA;

    }

    use_password = (pwd && pwdlen != 0);

    use_salt = (salt && saltlen != 0);

    md_info = mbedtls_md_info_from_type(md_type);

    if (md_info == NULL) {

        return MBEDTLS_ERR_PKCS12_FEATURE_UNAVAILABLE;

    }

    mbedtls_md_init(&md_ctx);

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

        return ret;

    }

    hlen = mbedtls_md_get_size(md_info);

    if (hlen <= 32) {

        v = 64;

    } else {

        v = 128;

    }

    memset(diversifier, (unsigned char) id, v);

    if (use_salt != 0) {

        pkcs12_fill_buffer(salt_block, v, salt, saltlen);

    }

    if (use_password != 0) {

        pkcs12_fill_buffer(pwd_block,  v, pwd,  pwdlen);

    }

    p = data;

    while (datalen > 0) {

        // Calculate hash( diversifier || salt_block || pwd_block )

        if ((ret = mbedtls_md_starts(&md_ctx)) != 0) {

            goto exit;

        }

        if ((ret = mbedtls_md_update(&md_ctx, diversifier, v)) != 0) {

            goto exit;

        }

        if (use_salt != 0) {

            if ((ret = mbedtls_md_update(&md_ctx, salt_block, v)) != 0) {

                goto exit;

            }

        }

        if (use_password != 0) {

            if ((ret = mbedtls_md_update(&md_ctx, pwd_block, v)) != 0) {

                goto exit;

            }

        }

        if ((ret = mbedtls_md_finish(&md_ctx, hash_output)) != 0) {

            goto exit;

        }

        // Perform remaining ( iterations - 1 ) recursive hash calculations

        for (i = 1; i < (size_t) iterations; i++) {

            if ((ret = mbedtls_md(md_info, hash_output, hlen, hash_output)) != 0) {

                goto exit;

            }

        }

        use_len = (datalen > hlen) ? hlen : datalen;

        memcpy(p, hash_output, use_len);

        datalen -= use_len;

        p += use_len;

        if (datalen == 0) {

            break;

        }

        // Concatenating copies of hash_output into hash_block (B)

        pkcs12_fill_buffer(hash_block, v, hash_output, hlen);

        // B += 1

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

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

                break;

            }

        }

        if (use_salt != 0) {

            // salt_block += B

            c = 0;

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

                j = salt_block[i - 1] + hash_block[i - 1] + c;

                c = MBEDTLS_BYTE_1(j);

                salt_block[i - 1] = MBEDTLS_BYTE_0(j);

            }

        }

        if (use_password != 0) {

            // pwd_block  += B

            c = 0;

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

                j = pwd_block[i - 1] + hash_block[i - 1] + c;

                c = MBEDTLS_BYTE_1(j);

                pwd_block[i - 1] = MBEDTLS_BYTE_0(j);

            }

        }

    }

    ret = 0;

exit:

    mbedtls_platform_zeroize(salt_block, sizeof(salt_block));

    mbedtls_platform_zeroize(pwd_block, sizeof(pwd_block));

    mbedtls_platform_zeroize(hash_block, sizeof(hash_block));

    mbedtls_platform_zeroize(hash_output, sizeof(hash_output));

    mbedtls_md_free(&md_ctx);

    return ret;

}

#endif /* MBEDTLS_PKCS12_C */