godot/thirdparty/mbedtls/library/pem.c

/*
 *  Privacy Enhanced Mail (PEM) decoding
 *
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
 */

#include "common.h"

#if defined(MBEDTLS_PEM_PARSE_C) || defined(MBEDTLS_PEM_WRITE_C)

#include "mbedtls/pem.h"
#include "mbedtls/base64.h"
#include "mbedtls/des.h"
#include "mbedtls/aes.h"
#include "mbedtls/md.h"
#include "mbedtls/cipher.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"

#include <string.h>

#include "mbedtls/platform.h"

#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "psa/crypto.h"
#endif

#if defined(MBEDTLS_MD_CAN_MD5) &&  \
    defined(MBEDTLS_CIPHER_MODE_CBC) &&                             \
    (defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C))
#define PEM_RFC1421
#endif /* MBEDTLS_MD_CAN_MD5 &&
          MBEDTLS_CIPHER_MODE_CBC &&
          ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */

#if defined(MBEDTLS_PEM_PARSE_C)
void mbedtls_pem_init(mbedtls_pem_context *ctx)
{ … }

#if defined(PEM_RFC1421)
/*
 * Read a 16-byte hex string and convert it to binary
 */
static int pem_get_iv(const unsigned char *s, unsigned char *iv,
                      size_t iv_len)
{ … }

static int pem_pbkdf1(unsigned char *key, size_t keylen,
                      unsigned char *iv,
                      const unsigned char *pwd, size_t pwdlen)
{ … }

#if defined(MBEDTLS_DES_C)
/*
 * Decrypt with DES-CBC, using PBKDF1 for key derivation
 */
static int pem_des_decrypt(unsigned char des_iv[8],
                           unsigned char *buf, size_t buflen,
                           const unsigned char *pwd, size_t pwdlen)
{
    mbedtls_des_context des_ctx;
    unsigned char des_key[8];
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    mbedtls_des_init(&des_ctx);

    if ((ret = pem_pbkdf1(des_key, 8, des_iv, pwd, pwdlen)) != 0) {
        goto exit;
    }

    if ((ret = mbedtls_des_setkey_dec(&des_ctx, des_key)) != 0) {
        goto exit;
    }
    ret = mbedtls_des_crypt_cbc(&des_ctx, MBEDTLS_DES_DECRYPT, buflen,
                                des_iv, buf, buf);

exit:
    mbedtls_des_free(&des_ctx);
    mbedtls_platform_zeroize(des_key, 8);

    return ret;
}

/*
 * Decrypt with 3DES-CBC, using PBKDF1 for key derivation
 */
static int pem_des3_decrypt(unsigned char des3_iv[8],
                            unsigned char *buf, size_t buflen,
                            const unsigned char *pwd, size_t pwdlen)
{
    mbedtls_des3_context des3_ctx;
    unsigned char des3_key[24];
    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    mbedtls_des3_init(&des3_ctx);

    if ((ret = pem_pbkdf1(des3_key, 24, des3_iv, pwd, pwdlen)) != 0) {
        goto exit;
    }

    if ((ret = mbedtls_des3_set3key_dec(&des3_ctx, des3_key)) != 0) {
        goto exit;
    }
    ret = mbedtls_des3_crypt_cbc(&des3_ctx, MBEDTLS_DES_DECRYPT, buflen,
                                 des3_iv, buf, buf);

exit:
    mbedtls_des3_free(&des3_ctx);
    mbedtls_platform_zeroize(des3_key, 24);

    return ret;
}
#endif /* MBEDTLS_DES_C */

#if defined(MBEDTLS_AES_C)
/*
 * Decrypt with AES-XXX-CBC, using PBKDF1 for key derivation
 */
static int pem_aes_decrypt(unsigned char aes_iv[16], unsigned int keylen,
                           unsigned char *buf, size_t buflen,
                           const unsigned char *pwd, size_t pwdlen)
{ … }
#endif /* MBEDTLS_AES_C */

#if defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C)
static int pem_check_pkcs_padding(unsigned char *input, size_t input_len, size_t *data_len)
{ … }
#endif /* MBEDTLS_DES_C || MBEDTLS_AES_C */

#endif /* PEM_RFC1421 */

int mbedtls_pem_read_buffer(mbedtls_pem_context *ctx, const char *header, const char *footer,
                            const unsigned char *data, const unsigned char *pwd,
                            size_t pwdlen, size_t *use_len)
{ … }

void mbedtls_pem_free(mbedtls_pem_context *ctx)
{ … }
#endif /* MBEDTLS_PEM_PARSE_C */

#if defined(MBEDTLS_PEM_WRITE_C)
int mbedtls_pem_write_buffer(const char *header, const char *footer,
                             const unsigned char *der_data, size_t der_len,
                             unsigned char *buf, size_t buf_len, size_t *olen)
{ … }
#endif /* MBEDTLS_PEM_WRITE_C */
#endif /* MBEDTLS_PEM_PARSE_C || MBEDTLS_PEM_WRITE_C */