text: /*
   * Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the Apache License 2.0 (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  /*
   * RSA low level APIs are deprecated for public use, but still ok for
   * internal use.
   */
  #include "internal/deprecated.h"
  
  #include <openssl/crypto.h>
  #include <openssl/evp.h>
  #include <openssl/core_dispatch.h>
  #include <openssl/core_names.h>
  #include <openssl/rsa.h>
  #include <openssl/params.h>
  #include <openssl/err.h>
  #include <openssl/proverr.h>
  /* Just for SSL_MAX_MASTER_KEY_LENGTH */
  #include <openssl/ssl.h>
  #include "internal/constant_time.h"
  #include "internal/sizes.h"
  #include "crypto/rsa.h"
  #include "prov/provider_ctx.h"
  #include "prov/implementations.h"
  #include "prov/providercommon.h"
  #include "prov/securitycheck.h"
  
  #include <stdlib.h>
  
  static OSSL_FUNC_asym_cipher_newctx_fn rsa_newctx;
  static OSSL_FUNC_asym_cipher_encrypt_init_fn rsa_encrypt_init;
  static OSSL_FUNC_asym_cipher_encrypt_fn rsa_encrypt;
  static OSSL_FUNC_asym_cipher_decrypt_init_fn rsa_decrypt_init;
  static OSSL_FUNC_asym_cipher_decrypt_fn rsa_decrypt;
  static OSSL_FUNC_asym_cipher_freectx_fn rsa_freectx;
  static OSSL_FUNC_asym_cipher_dupctx_fn rsa_dupctx;
  static OSSL_FUNC_asym_cipher_get_ctx_params_fn rsa_get_ctx_params;
  static OSSL_FUNC_asym_cipher_gettable_ctx_params_fn rsa_gettable_ctx_params;
  static OSSL_FUNC_asym_cipher_set_ctx_params_fn rsa_set_ctx_params;
  static OSSL_FUNC_asym_cipher_settable_ctx_params_fn rsa_settable_ctx_params;
  
  static OSSL_ITEM padding_item[] = {
      { RSA_PKCS1_PADDING,        OSSL_PKEY_RSA_PAD_MODE_PKCSV15 },
      { RSA_NO_PADDING,           OSSL_PKEY_RSA_PAD_MODE_NONE },
      { RSA_PKCS1_OAEP_PADDING,   OSSL_PKEY_RSA_PAD_MODE_OAEP }, /* Correct spelling first */
      { RSA_PKCS1_OAEP_PADDING,   "oeap"   },
      { RSA_X931_PADDING,         OSSL_PKEY_RSA_PAD_MODE_X931 },
      { 0,                        NULL     }
  };
  
  /*
   * What's passed as an actual key is defined by the KEYMGMT interface.
   * We happen to know that our KEYMGMT simply passes RSA structures, so
   * we use that here too.
   */
  
  typedef struct {
      OSSL_LIB_CTX *libctx;
      RSA *rsa;
      int pad_mode;
      int operation;
      /* OAEP message digest */
      EVP_MD *oaep_md;
      /* message digest for MGF1 */
      EVP_MD *mgf1_md;
      /* OAEP label */
      unsigned char *oaep_label;
      size_t oaep_labellen;
      /* TLS padding */
      unsigned int client_version;
      unsigned int alt_version;
  } PROV_RSA_CTX;
  
  static void *rsa_newctx(void *provctx)
  {
      PROV_RSA_CTX *prsactx;
  
      if (!ossl_prov_is_running())
          return NULL;
      prsactx = OPENSSL_zalloc(sizeof(PROV_RSA_CTX));
      if (prsactx == NULL)
          return NULL;
      prsactx->libctx = PROV_LIBCTX_OF(provctx);
  
      return prsactx;
  }
  
  static int rsa_init(void *vprsactx, void *vrsa, const OSSL_PARAM params[],
                      int operation)
  {
      PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
  
      if (!ossl_prov_is_running() || prsactx == NULL || vrsa == NULL)
          return 0;
  
      if (!ossl_rsa_check_key(prsactx->libctx, vrsa, operation))
          return 0;
  
      if (!RSA_up_ref(vrsa))
          return 0;
      RSA_free(prsactx->rsa);
      prsactx->rsa = vrsa;
      prsactx->operation = operation;
  
      switch (RSA_test_flags(prsactx->rsa, RSA_FLAG_TYPE_MASK)) {
      case RSA_FLAG_TYPE_RSA:
          prsactx->pad_mode = RSA_PKCS1_PADDING;
          break;
      default:
          /* This should not happen due to the check above */
          ERR_raise(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR);
          return 0;
      }
      return rsa_set_ctx_params(prsactx, params);
  }
  
  static int rsa_encrypt_init(void *vprsactx, void *vrsa,
                              const OSSL_PARAM params[])
  {
      return rsa_init(vprsactx, vrsa, params, EVP_PKEY_OP_ENCRYPT);
  }
  
  static int rsa_decrypt_init(void *vprsactx, void *vrsa,
                              const OSSL_PARAM params[])
  {
      return rsa_init(vprsactx, vrsa, params, EVP_PKEY_OP_DECRYPT);
  }
  
  static int rsa_encrypt(void *vprsactx, unsigned char *out, size_t *outlen,
                         size_t outsize, const unsigned char *in, size_t inlen)
  {
      PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
      int ret;
  
      if (!ossl_prov_is_running())
          return 0;
  
      if (out == NULL) {
          size_t len = RSA_size(prsactx->rsa);
  
          if (len == 0) {
              ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY);
              return 0;
          }
          *outlen = len;
          return 1;
      }
  
      if (prsactx->pad_mode == RSA_PKCS1_OAEP_PADDING) {
          int rsasize = RSA_size(prsactx->rsa);
          unsigned char *tbuf;
  
          if ((tbuf = OPENSSL_malloc(rsasize)) == NULL) {
              ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
              return 0;
          }
          if (prsactx->oaep_md == NULL) {
              OPENSSL_free(tbuf);
              prsactx->oaep_md = EVP_MD_fetch(prsactx->libctx, "SHA-1", NULL);
              ERR_raise(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR);
              return 0;
          }
          ret =
              ossl_rsa_padding_add_PKCS1_OAEP_mgf1_ex(prsactx->libctx, tbuf,
                                                      rsasize, in, inlen,
                                                      prsactx->oaep_label,
                                                      prsactx->oaep_labellen,
                                                      prsactx->oaep_md,
                                                      prsactx->mgf1_md);
  
          if (!ret) {
              OPENSSL_free(tbuf);
              return 0;
          }
          ret = RSA_public_encrypt(rsasize, tbuf, out, prsactx->rsa,
                                   RSA_NO_PADDING);
          OPENSSL_free(tbuf);
      } else {
          ret = RSA_public_encrypt(inlen, in, out, prsactx->rsa,
                                   prsactx->pad_mode);
      }
      /* A ret value of 0 is not an error */
      if (ret < 0)
          return ret;
      *outlen = ret;
      return 1;
  }
  
  static int rsa_decrypt(void *vprsactx, unsigned char *out, size_t *outlen,
                         size_t outsize, const unsigned char *in, size_t inlen)
  {
      PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
      int ret;
      size_t len = RSA_size(prsactx->rsa);
  
      if (!ossl_prov_is_running())
          return 0;
  
      if (prsactx->pad_mode == RSA_PKCS1_WITH_TLS_PADDING) {
          if (out == NULL) {
              *outlen = SSL_MAX_MASTER_KEY_LENGTH;
              return 1;
          }
          if (outsize < SSL_MAX_MASTER_KEY_LENGTH) {
              ERR_raise(ERR_LIB_PROV, PROV_R_BAD_LENGTH);
              return 0;
          }
      } else {
          if (out == NULL) {
              if (len == 0) {
                  ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY);
                  return 0;
              }
              *outlen = len;
              return 1;
          }
  
          if (outsize < len) {
              ERR_raise(ERR_LIB_PROV, PROV_R_BAD_LENGTH);
              return 0;
          }
      }
  
      if (prsactx->pad_mode == RSA_PKCS1_OAEP_PADDING
              || prsactx->pad_mode == RSA_PKCS1_WITH_TLS_PADDING) {
          unsigned char *tbuf;
  
          if ((tbuf = OPENSSL_malloc(len)) == NULL) {
              ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
              return 0;
          }
          ret = RSA_private_decrypt(inlen, in, tbuf, prsactx->rsa,
                                    RSA_NO_PADDING);
          /*
           * With no padding then, on success ret should be len, otherwise an
           * error occurred (non-constant time)
           */
          if (ret != (int)len) {
              OPENSSL_free(tbuf);
              ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_DECRYPT);
              return 0;
          }
          if (prsactx->pad_mode == RSA_PKCS1_OAEP_PADDING) {
              if (prsactx->oaep_md == NULL) {
                  prsactx->oaep_md = EVP_MD_fetch(prsactx->libctx, "SHA-1", NULL);
                  if (prsactx->oaep_md == NULL) {
                      OPENSSL_free(tbuf);
                      ERR_raise(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR);
                      return 0;
                  }
              }
              ret = RSA_padding_check_PKCS1_OAEP_mgf1(out, outsize, tbuf,
                                                      len, len,
                                                      prsactx->oaep_label,
                                                      prsactx->oaep_labellen,
                                                      prsactx->oaep_md,
                                                      prsactx->mgf1_md);
          } else {
              /* RSA_PKCS1_WITH_TLS_PADDING */
              if (prsactx->client_version <= 0) {
                  ERR_raise(ERR_LIB_PROV, PROV_R_BAD_TLS_CLIENT_VERSION);
                  OPENSSL_free(tbuf);
                  return 0;
              }
              ret = ossl_rsa_padding_check_PKCS1_type_2_TLS(
                          prsactx->libctx, out, outsize, tbuf, len,
                          prsactx->client_version, prsactx->alt_version);
          }
          OPENSSL_free(tbuf);
      } else {
          ret = RSA_private_decrypt(inlen, in, out, prsactx->rsa,
                                    prsactx->pad_mode);
      }
      *outlen = constant_time_select_s(constant_time_msb_s(ret), *outlen, ret);
      ret = constant_time_select_int(constant_time_msb(ret), 0, 1);
      return ret;
  }
  
  static void rsa_freectx(void *vprsactx)
  {
      PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
  
      RSA_free(prsactx->rsa);
  
      EVP_MD_free(prsactx->oaep_md);
      EVP_MD_free(prsactx->mgf1_md);
      OPENSSL_free(prsactx->oaep_label);
  
      OPENSSL_free(prsactx);
  }
  
  static void *rsa_dupctx(void *vprsactx)
  {
      PROV_RSA_CTX *srcctx = (PROV_RSA_CTX *)vprsactx;
      PROV_RSA_CTX *dstctx;
  
      if (!ossl_prov_is_running())
          return NULL;
  
      dstctx = OPENSSL_zalloc(sizeof(*srcctx));
      if (dstctx == NULL)
          return NULL;
  
      *dstctx = *srcctx;
      if (dstctx->rsa != NULL && !RSA_up_ref(dstctx->rsa)) {
          OPENSSL_free(dstctx);
          return NULL;
      }
  
      if (dstctx->oaep_md != NULL && !EVP_MD_up_ref(dstctx->oaep_md)) {
          RSA_free(dstctx->rsa);
          OPENSSL_free(dstctx);
          return NULL;
      }
  
      if (dstctx->mgf1_md != NULL && !EVP_MD_up_ref(dstctx->mgf1_md)) {
          RSA_free(dstctx->rsa);
          EVP_MD_free(dstctx->oaep_md);
          OPENSSL_free(dstctx);
          return NULL;
      }
  
      return dstctx;
  }
  
  static int rsa_get_ctx_params(void *vprsactx, OSSL_PARAM *params)
  {
      PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
      OSSL_PARAM *p;
  
      if (prsactx == NULL)
          return 0;
  
      p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_PAD_MODE);
      if (p != NULL)
          switch (p->data_type) {
          case OSSL_PARAM_INTEGER: /* Support for legacy pad mode number */
              if (!OSSL_PARAM_set_int(p, prsactx->pad_mode))
                  return 0;
              break;
          case OSSL_PARAM_UTF8_STRING:
              {
                  int i;
                  const char *word = NULL;
  
                  for (i = 0; padding_item[i].id != 0; i++) {
                      if (prsactx->pad_mode == (int)padding_item[i].id) {
                          word = padding_item[i].ptr;
                          break;
                      }
                  }
  
                  if (word != NULL) {
                      if (!OSSL_PARAM_set_utf8_string(p, word))
                          return 0;
                  } else {
                      ERR_raise(ERR_LIB_PROV, ERR_R_INTERNAL_ERROR);
                  }
              }
              break;
          default:
              return 0;
          }
  
      p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST);
      if (p != NULL && !OSSL_PARAM_set_utf8_string(p, prsactx->oaep_md == NULL
                                                      ? ""
                                                      : EVP_MD_name(prsactx->oaep_md)))
          return 0;
  
      p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST);
      if (p != NULL) {
          EVP_MD *mgf1_md = prsactx->mgf1_md == NULL ? prsactx->oaep_md
                                                     : prsactx->mgf1_md;
  
          if (!OSSL_PARAM_set_utf8_string(p, mgf1_md == NULL
                                             ? ""
                                             : EVP_MD_name(mgf1_md)))
          return 0;
      }
  
      p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL);
      if (p != NULL &&
          !OSSL_PARAM_set_octet_ptr(p, prsactx->oaep_label,
                                    prsactx->oaep_labellen))
          return 0;
  
      p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION);
      if (p != NULL && !OSSL_PARAM_set_uint(p, prsactx->client_version))
          return 0;
  
      p = OSSL_PARAM_locate(params, OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION);
      if (p != NULL && !OSSL_PARAM_set_uint(p, prsactx->alt_version))
          return 0;
  
      return 1;
  }
  
  static const OSSL_PARAM known_gettable_ctx_params[] = {
      OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST, NULL, 0),
      OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_PAD_MODE, NULL, 0),
      OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST, NULL, 0),
      OSSL_PARAM_DEFN(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL, OSSL_PARAM_OCTET_PTR,
                      NULL, 0),
      OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION, NULL),
      OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION, NULL),
      OSSL_PARAM_END
  };
  
  static const OSSL_PARAM *rsa_gettable_ctx_params(ossl_unused void *vprsactx,
                                                   ossl_unused void *provctx)
  {
      return known_gettable_ctx_params;
  }
  
  static int rsa_set_ctx_params(void *vprsactx, const OSSL_PARAM params[])
  {
      PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
      const OSSL_PARAM *p;
      char mdname[OSSL_MAX_NAME_SIZE];
      char mdprops[OSSL_MAX_PROPQUERY_SIZE] = { '\0' };
      char *str = mdname;
  
      if (prsactx == NULL)
          return 0;
      if (params == NULL)
          return 1;
  
      p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST);
      if (p != NULL) {
          if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdname)))
              return 0;
  
          str = mdprops;
          p = OSSL_PARAM_locate_const(params,
                                      OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST_PROPS);
          if (p != NULL) {
              if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdprops)))
                  return 0;
          }
  
          EVP_MD_free(prsactx->oaep_md);
          prsactx->oaep_md = EVP_MD_fetch(prsactx->libctx, mdname, mdprops);
  
          if (prsactx->oaep_md == NULL)
              return 0;
      }
  
      p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_PAD_MODE);
      if (p != NULL) {
          int pad_mode = 0;
  
          switch (p->data_type) {
          case OSSL_PARAM_INTEGER: /* Support for legacy pad mode number */
              if (!OSSL_PARAM_get_int(p, &pad_mode))
                  return 0;
              break;
          case OSSL_PARAM_UTF8_STRING:
              {
                  int i;
  
                  if (p->data == NULL)
                      return 0;
  
                  for (i = 0; padding_item[i].id != 0; i++) {
                      if (strcmp(p->data, padding_item[i].ptr) == 0) {
                          pad_mode = padding_item[i].id;
                          break;
                      }
                  }
              }
              break;
          default:
              return 0;
          }
  
          /*
           * PSS padding is for signatures only so is not compatible with
           * asymmetric cipher use.
           */
          if (pad_mode == RSA_PKCS1_PSS_PADDING)
              return 0;
          if (pad_mode == RSA_PKCS1_OAEP_PADDING && prsactx->oaep_md == NULL) {
              prsactx->oaep_md = EVP_MD_fetch(prsactx->libctx, "SHA1", mdprops);
              if (prsactx->oaep_md == NULL)
                  return 0;
          }
          prsactx->pad_mode = pad_mode;
      }
  
      p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST);
      if (p != NULL) {
          if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdname)))
              return 0;
  
          str = mdprops;
          p = OSSL_PARAM_locate_const(params,
                                      OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST_PROPS);
          if (p != NULL) {
              if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdprops)))
                  return 0;
          } else {
              str = NULL;
          }
  
          EVP_MD_free(prsactx->mgf1_md);
          prsactx->mgf1_md = EVP_MD_fetch(prsactx->libctx, mdname, str);
  
          if (prsactx->mgf1_md == NULL)
              return 0;
      }
  
      p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL);
      if (p != NULL) {
          void *tmp_label = NULL;
          size_t tmp_labellen;
  
          if (!OSSL_PARAM_get_octet_string(p, &tmp_label, 0, &tmp_labellen))
              return 0;
          OPENSSL_free(prsactx->oaep_label);
          prsactx->oaep_label = (unsigned char *)tmp_label;
          prsactx->oaep_labellen = tmp_labellen;
      }
  
      p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION);
      if (p != NULL) {
          unsigned int client_version;
  
          if (!OSSL_PARAM_get_uint(p, &client_version))
              return 0;
          prsactx->client_version = client_version;
      }
  
      p = OSSL_PARAM_locate_const(params, OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION);
      if (p != NULL) {
          unsigned int alt_version;
  
          if (!OSSL_PARAM_get_uint(p, &alt_version))
              return 0;
          prsactx->alt_version = alt_version;
      }
  
      return 1;
  }
  
  static const OSSL_PARAM known_settable_ctx_params[] = {
      OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST, NULL, 0),
      OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_PAD_MODE, NULL, 0),
      OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST, NULL, 0),
      OSSL_PARAM_utf8_string(OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST_PROPS, NULL, 0),
      OSSL_PARAM_octet_string(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL, NULL, 0),
      OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_CLIENT_VERSION, NULL),
      OSSL_PARAM_uint(OSSL_ASYM_CIPHER_PARAM_TLS_NEGOTIATED_VERSION, NULL),
      OSSL_PARAM_END
  };
  
  static const OSSL_PARAM *rsa_settable_ctx_params(ossl_unused void *vprsactx,
                                                   ossl_unused void *provctx)
  {
      return known_settable_ctx_params;
  }
  
  const OSSL_DISPATCH ossl_rsa_asym_cipher_functions[] = {
      { OSSL_FUNC_ASYM_CIPHER_NEWCTX, (void (*)(void))rsa_newctx },
      { OSSL_FUNC_ASYM_CIPHER_ENCRYPT_INIT, (void (*)(void))rsa_encrypt_init },
      { OSSL_FUNC_ASYM_CIPHER_ENCRYPT, (void (*)(void))rsa_encrypt },
      { OSSL_FUNC_ASYM_CIPHER_DECRYPT_INIT, (void (*)(void))rsa_decrypt_init },
      { OSSL_FUNC_ASYM_CIPHER_DECRYPT, (void (*)(void))rsa_decrypt },
      { OSSL_FUNC_ASYM_CIPHER_FREECTX, (void (*)(void))rsa_freectx },
      { OSSL_FUNC_ASYM_CIPHER_DUPCTX, (void (*)(void))rsa_dupctx },
      { OSSL_FUNC_ASYM_CIPHER_GET_CTX_PARAMS,
        (void (*)(void))rsa_get_ctx_params },
      { OSSL_FUNC_ASYM_CIPHER_GETTABLE_CTX_PARAMS,
        (void (*)(void))rsa_gettable_ctx_params },
      { OSSL_FUNC_ASYM_CIPHER_SET_CTX_PARAMS,
        (void (*)(void))rsa_set_ctx_params },
      { OSSL_FUNC_ASYM_CIPHER_SETTABLE_CTX_PARAMS,
        (void (*)(void))rsa_settable_ctx_params },
      { 0, NULL }
  };
  