/src/bind9/lib/dns/opensslrsa_link.c

Source
/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file */

#include <inttypes.h>
#include <stdbool.h>

#include <openssl/bn.h>
#include <openssl/err.h>
#include <openssl/objects.h>
#include <openssl/rsa.h>

#include <isc/mem.h>
#include <isc/ossl_wrap.h>
#include <isc/result.h>
#include <isc/safe.h>
#include <isc/string.h>
#include <isc/util.h>

#include "dst_internal.h"
#include "dst_openssl.h"
#include "dst_parse.h"
#include "openssl_shim.h"

#define OPENSSLRSA_MAX_MODULUS_BITS 4096
#define OPENSSLRSA_MIN_MODULUS_BITS 512

static BIGNUM *rsa_exponent_min = NULL;
static BIGNUM *rsa_exponent_max = NULL;

/*
 * Accept odd public exponents in [3, 2^32 + 1].  That covers every Fermat
 * prime up to F5 and the odd intermediate values seen on the wire.
 */
static bool
rsa_exponent_in_range(const BIGNUM *e) {
  if (!BN_is_odd(e)) {
    return false;
  }

  if (BN_cmp(e, rsa_exponent_min) < 0) {
    return false;
  }

  if (BN_cmp(e, rsa_exponent_max) > 0) {
    return false;
  }

  return true;
}

/* length byte + 1.2.840.113549.1.1.11 BER encoded RFC 4055 */
static unsigned char oid_rsasha256[] = { 0x0b, 0x06, 0x09, 0x2a, 0x86, 0x48,
           0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0b };

/* length byte + 1.2.840.113549.1.1.13 BER encoded RFC 4055 */
static unsigned char oid_rsasha512[] = { 0x0b, 0x06, 0x09, 0x2a, 0x86, 0x48,
           0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0d };

static bool
opensslrsa_valid_key_alg(unsigned int key_alg) {
  switch (key_alg) {
  case DST_ALG_RSASHA1:
  case DST_ALG_NSEC3RSASHA1:
  case DST_ALG_RSASHA256:
  case DST_ALG_RSASHA512:
  case DST_ALG_RSASHA256PRIVATEOID:
  case DST_ALG_RSASHA512PRIVATEOID:
    return true;
  default:
    return false;
  }
}

static isc_result_t
opensslrsa_createctx(dst_key_t *key, dst_context_t *dctx) {
  EVP_MD_CTX *evp_md_ctx;
  const EVP_MD *type = NULL;

  UNUSED(key);
  REQUIRE(dctx != NULL && dctx->key != NULL);
  REQUIRE(opensslrsa_valid_key_alg(dctx->key->key_alg));

  /*
   * Reject incorrect RSA key lengths.
   */
  switch (dctx->key->key_alg) {
  case DST_ALG_RSASHA1:
  case DST_ALG_NSEC3RSASHA1:
    /* From RFC 3110 */
    if (dctx->key->key_size > 4096) {
      return ISC_R_FAILURE;
    }
    break;
  case DST_ALG_RSASHA256:
  case DST_ALG_RSASHA256PRIVATEOID:
    /* From RFC 5702 */
    if (dctx->key->key_size < 512 || dctx->key->key_size > 4096) {
      return ISC_R_FAILURE;
    }
    break;
  case DST_ALG_RSASHA512:
  case DST_ALG_RSASHA512PRIVATEOID:
    /* From RFC 5702 */
    if (dctx->key->key_size < 1024 || dctx->key->key_size > 4096) {
      return ISC_R_FAILURE;
    }
    break;
  default:
    UNREACHABLE();
  }

  evp_md_ctx = EVP_MD_CTX_create();
  if (evp_md_ctx == NULL) {
    return dst__openssl_toresult(ISC_R_NOMEMORY);
  }

  switch (dctx->key->key_alg) {
  case DST_ALG_RSASHA1:
  case DST_ALG_NSEC3RSASHA1:
    type = isc__crypto_md[ISC_MD_SHA1]; /* SHA1 + RSA */
    break;
  case DST_ALG_RSASHA256:
  case DST_ALG_RSASHA256PRIVATEOID:
    type = isc__crypto_md[ISC_MD_SHA256]; /* SHA256 + RSA */
    break;
  case DST_ALG_RSASHA512:
  case DST_ALG_RSASHA512PRIVATEOID:
    type = isc__crypto_md[ISC_MD_SHA512];
    break;
  default:
    UNREACHABLE();
  }

  if (!EVP_DigestInit_ex(evp_md_ctx, type, NULL)) {
    EVP_MD_CTX_destroy(evp_md_ctx);
    return dst__openssl_toresult3(
      dctx->category, "EVP_DigestInit_ex", ISC_R_FAILURE);
  }
  dctx->ctxdata.evp_md_ctx = evp_md_ctx;

  return ISC_R_SUCCESS;
}

static void
opensslrsa_destroyctx(dst_context_t *dctx) {
  EVP_MD_CTX *evp_md_ctx = NULL;

  REQUIRE(dctx != NULL && dctx->key != NULL);
  REQUIRE(opensslrsa_valid_key_alg(dctx->key->key_alg));

  evp_md_ctx = dctx->ctxdata.evp_md_ctx;

  if (evp_md_ctx != NULL) {
    EVP_MD_CTX_destroy(evp_md_ctx);
    dctx->ctxdata.evp_md_ctx = NULL;
  }
}

static isc_result_t
opensslrsa_adddata(dst_context_t *dctx, const isc_region_t *data) {
  EVP_MD_CTX *evp_md_ctx = NULL;

  REQUIRE(dctx != NULL && dctx->key != NULL);
  REQUIRE(opensslrsa_valid_key_alg(dctx->key->key_alg));

  evp_md_ctx = dctx->ctxdata.evp_md_ctx;

  if (!EVP_DigestUpdate(evp_md_ctx, data->base, data->length)) {
    return dst__openssl_toresult3(
      dctx->category, "EVP_DigestUpdate", ISC_R_FAILURE);
  }
  return ISC_R_SUCCESS;
}

static isc_result_t
opensslrsa_sign(dst_context_t *dctx, isc_buffer_t *sig) {
  dst_key_t *key = NULL;
  isc_region_t r;
  unsigned int siglen = 0;
  EVP_MD_CTX *evp_md_ctx = NULL;
  EVP_PKEY *pkey = NULL;
  unsigned int len = 0;

  REQUIRE(dctx != NULL && dctx->key != NULL);
  REQUIRE(opensslrsa_valid_key_alg(dctx->key->key_alg));

  key = dctx->key;
  evp_md_ctx = dctx->ctxdata.evp_md_ctx;
  pkey = key->keydata.pkeypair.priv;

  /*
   * Account to the space the OIDs and DNS names consume.
   */
  switch (key->key_alg) {
  case DST_ALG_RSASHA256PRIVATEOID:
    len = sizeof(oid_rsasha256);
    break;
  case DST_ALG_RSASHA512PRIVATEOID:
    len = sizeof(oid_rsasha512);
    break;
  }

  isc_buffer_availableregion(sig, &r);

  if (r.length < (unsigned int)EVP_PKEY_size(pkey) + len) {
    return ISC_R_NOSPACE;
  }

  /*
   * Add OID and DNS names to start of signature.
   */
  switch (key->key_alg) {
  case DST_ALG_RSASHA256PRIVATEOID:
    isc_buffer_putmem(sig, oid_rsasha256, sizeof(oid_rsasha256));
    isc_region_consume(&r, sizeof(oid_rsasha256));
    break;
  case DST_ALG_RSASHA512PRIVATEOID:
    isc_buffer_putmem(sig, oid_rsasha512, sizeof(oid_rsasha512));
    isc_region_consume(&r, sizeof(oid_rsasha512));
    break;
  }

  if (!EVP_SignFinal(evp_md_ctx, r.base, &siglen, pkey)) {
    return dst__openssl_toresult3(dctx->category, "EVP_SignFinal",
                ISC_R_FAILURE);
  }
  isc_buffer_add(sig, siglen);

  return ISC_R_SUCCESS;
}

static isc_result_t
opensslrsa_verify(dst_context_t *dctx, const isc_region_t *sig) {
  dst_key_t *key = NULL;
  int status = 0;
  EVP_MD_CTX *evp_md_ctx = NULL;
  EVP_PKEY *pkey = NULL;
  const unsigned char *base = sig->base;
  unsigned int length = sig->length;

  REQUIRE(dctx != NULL && dctx->key != NULL);
  REQUIRE(opensslrsa_valid_key_alg(dctx->key->key_alg));

  key = dctx->key;
  evp_md_ctx = dctx->ctxdata.evp_md_ctx;
  pkey = key->keydata.pkeypair.pub;

  if (!isc_ossl_wrap_rsa_modulus_bits_in_range(
        pkey, OPENSSLRSA_MIN_MODULUS_BITS,
        OPENSSLRSA_MAX_MODULUS_BITS) ||
      !isc_ossl_wrap_rsa_exponent_is_allowed(pkey))
  {
    return DST_R_VERIFYFAILURE;
  }

  /*
   * Check identifying OID in front of public key material.
   */
  switch (key->key_alg) {
  case DST_ALG_RSASHA256PRIVATEOID:
    if (length < sizeof(oid_rsasha256) ||
        memcmp(base, oid_rsasha256, sizeof(oid_rsasha256)) != 0)
    {
      return DST_R_VERIFYFAILURE;
    }
    base += sizeof(oid_rsasha256);
    length -= sizeof(oid_rsasha256);
    break;
  case DST_ALG_RSASHA512PRIVATEOID:
    if (length < sizeof(oid_rsasha512) ||
        memcmp(base, oid_rsasha512, sizeof(oid_rsasha512)) != 0)
    {
      return DST_R_VERIFYFAILURE;
    }
    base += sizeof(oid_rsasha512);
    length -= sizeof(oid_rsasha512);
    break;
  }

  status = EVP_VerifyFinal(evp_md_ctx, base, length, pkey);
  switch (status) {
  case 1:
    return ISC_R_SUCCESS;
  case 0:
    return dst__openssl_toresult(DST_R_VERIFYFAILURE);
  default:
    return dst__openssl_toresult3(dctx->category, "EVP_VerifyFinal",
                DST_R_VERIFYFAILURE);
  }
}

static isc_result_t
opensslrsa_generate(dst_key_t *key, int unused, void (*callback)(int)) {
  isc_result_t result;
  EVP_PKEY *pkey = NULL;

  UNUSED(unused);

  /*
   * Reject incorrect RSA key lengths.
   */
  switch (key->key_alg) {
  case DST_ALG_RSASHA1:
  case DST_ALG_NSEC3RSASHA1:
    /* From RFC 3110 */
    if (key->key_size > 4096) {
      CLEANUP(DST_R_INVALIDPARAM);
    }
    break;
  case DST_ALG_RSASHA256:
  case DST_ALG_RSASHA256PRIVATEOID:
    /* From RFC 5702 */
    if (key->key_size < 512 || key->key_size > 4096) {
      CLEANUP(DST_R_INVALIDPARAM);
    }
    break;
  case DST_ALG_RSASHA512:
  case DST_ALG_RSASHA512PRIVATEOID:
    /* From RFC 5702 */
    if (key->key_size < 1024 || key->key_size > 4096) {
      CLEANUP(DST_R_INVALIDPARAM);
    }
    break;
  default:
    UNREACHABLE();
  }

  if (key->label != NULL) {
    CHECK(isc_ossl_wrap_generate_pkcs11_rsa_key(
      key->label, key->key_size, &pkey));
  } else {
    CHECK(isc_ossl_wrap_generate_rsa_key(callback, key->key_size,
                 &pkey));
  }

  key->keydata.pkeypair.pub = pkey;
  key->keydata.pkeypair.priv = pkey;
  pkey = NULL;
  result = ISC_R_SUCCESS;

cleanup:
  EVP_PKEY_free(pkey);
  return result;
}

static isc_result_t
opensslrsa_todns(const dst_key_t *key, isc_buffer_t *data) {
  isc_region_t r;
  unsigned int e_bytes;
  unsigned int mod_bytes;
  isc_result_t result;
  isc_ossl_wrap_rsa_components_t c = { 0 };

  REQUIRE(key->keydata.pkeypair.pub != NULL);

  isc_buffer_availableregion(data, &r);

  /*
   * Add identifying OID and DNS names to front of public key material.
   */
  switch (key->key_alg) {
  case DST_ALG_RSASHA256PRIVATEOID:
    if (r.length < sizeof(oid_rsasha256)) {
      CLEANUP(ISC_R_NOSPACE);
    }
    isc_buffer_putmem(data, oid_rsasha256, sizeof(oid_rsasha256));
    isc_region_consume(&r, sizeof(oid_rsasha256));
    break;
  case DST_ALG_RSASHA512PRIVATEOID:
    if (r.length < sizeof(oid_rsasha512)) {
      CLEANUP(ISC_R_NOSPACE);
    }
    isc_buffer_putmem(data, oid_rsasha512, sizeof(oid_rsasha512));
    isc_region_consume(&r, sizeof(oid_rsasha512));
    break;
  }

  CHECK(isc_ossl_wrap_rsa_public_components(key->keydata.pkeypair.pub,
              &c));

  mod_bytes = BN_num_bytes(c.n);
  e_bytes = BN_num_bytes(c.e);

  if (e_bytes < 256) { /*%< key exponent is <= 2040 bits */
    if (r.length < 1) {
      CLEANUP(ISC_R_NOSPACE);
    }
    isc_buffer_putuint8(data, (uint8_t)e_bytes);
    isc_region_consume(&r, 1);
  } else {
    if (r.length < 3) {
      CLEANUP(ISC_R_NOSPACE);
    }
    isc_buffer_putuint8(data, 0);
    isc_buffer_putuint16(data, (uint16_t)e_bytes);
    isc_region_consume(&r, 3);
  }

  if (r.length < e_bytes + mod_bytes) {
    CLEANUP(ISC_R_NOSPACE);
  }

  BN_bn2bin(c.e, r.base);
  isc_region_consume(&r, e_bytes);
  BN_bn2bin(c.n, r.base);
  isc_region_consume(&r, mod_bytes);

  isc_buffer_add(data, e_bytes + mod_bytes);

cleanup:
  isc_ossl_wrap_rsa_components_cleanup(&c);
  return result;
}

static isc_result_t
opensslrsa_fromdns(dst_key_t *key, isc_buffer_t *data) {
  isc_result_t result;
  isc_region_t r;
  unsigned int e_bytes;
  unsigned int length;
  isc_ossl_wrap_rsa_components_t c = { .needs_cleanup = true };

  REQUIRE(opensslrsa_valid_key_alg(key->key_alg));

  isc_buffer_remainingregion(data, &r);
  if (r.length == 0) {
    CLEANUP(ISC_R_SUCCESS);
  }

  /*
   * Check identifying OID in front of public key material.
   */
  switch (key->key_alg) {
  case DST_ALG_RSASHA256PRIVATEOID:
    if (r.length < sizeof(oid_rsasha256) ||
        memcmp(r.base, oid_rsasha256, sizeof(oid_rsasha256)) != 0)
    {
      CLEANUP(DST_R_INVALIDPUBLICKEY);
    }
    isc_region_consume(&r, sizeof(oid_rsasha256));
    isc_buffer_forward(data, sizeof(oid_rsasha256));
    break;
  case DST_ALG_RSASHA512PRIVATEOID:
    if (r.length < sizeof(oid_rsasha512) ||
        memcmp(r.base, oid_rsasha512, sizeof(oid_rsasha512)) != 0)
    {
      CLEANUP(DST_R_INVALIDPUBLICKEY);
    }
    isc_region_consume(&r, sizeof(oid_rsasha512));
    isc_buffer_forward(data, sizeof(oid_rsasha512));
    break;
  }

  length = r.length;
  if (r.length < 1) {
    CLEANUP(DST_R_INVALIDPUBLICKEY);
  }

  e_bytes = *r.base;
  isc_region_consume(&r, 1);

  if (e_bytes == 0) {
    if (r.length < 2) {
      CLEANUP(DST_R_INVALIDPUBLICKEY);
    }
    e_bytes = (*r.base) << 8;
    isc_region_consume(&r, 1);
    e_bytes += *r.base;
    isc_region_consume(&r, 1);
  }

  if (r.length < e_bytes) {
    CLEANUP(DST_R_INVALIDPUBLICKEY);
  }
  c.e = BN_bin2bn(r.base, e_bytes, NULL);
  isc_region_consume(&r, e_bytes);
  c.n = BN_bin2bn(r.base, r.length, NULL);
  if (c.e == NULL || c.n == NULL) {
    CLEANUP(ISC_R_NOMEMORY);
  }
  if (BN_num_bits(c.n) < OPENSSLRSA_MIN_MODULUS_BITS ||
      BN_num_bits(c.n) > OPENSSLRSA_MAX_MODULUS_BITS)
  {
    CLEANUP(ISC_R_RANGE);
  }
  if (!rsa_exponent_in_range(c.e)) {
    CLEANUP(ISC_R_RANGE);
  }
  isc_buffer_forward(data, length);

  key->key_size = BN_num_bits(c.n);
  result = isc_ossl_wrap_load_rsa_public_from_components(
    &c, &key->keydata.pkeypair.pub);

cleanup:
  isc_ossl_wrap_rsa_components_cleanup(&c);
  return result;
}

static isc_result_t
opensslrsa_tofile(const dst_key_t *key, const char *directory) {
  isc_result_t result;
  dst_private_t priv = { 0 };
  unsigned char *bufs[8] = { NULL };
  unsigned short i = 0;
  isc_ossl_wrap_rsa_components_t c = { 0 };

  if (key->external) {
    return dst__privstruct_writefile(key, &priv, directory);
  }

  CHECK(isc_ossl_wrap_rsa_public_components(key->keydata.pkeypair.pub,
              &c));
  CHECK(isc_ossl_wrap_rsa_secret_components(key->keydata.pkeypair.priv,
              &c));

  priv.elements[i].tag = TAG_RSA_MODULUS;
  priv.elements[i].length = BN_num_bytes(c.n);
  bufs[i] = isc_mem_get(key->mctx, priv.elements[i].length);
  BN_bn2bin(c.n, bufs[i]);
  priv.elements[i].data = bufs[i];
  i++;

  priv.elements[i].tag = TAG_RSA_PUBLICEXPONENT;
  priv.elements[i].length = BN_num_bytes(c.e);
  bufs[i] = isc_mem_get(key->mctx, priv.elements[i].length);
  BN_bn2bin(c.e, bufs[i]);
  priv.elements[i].data = bufs[i];
  i++;

  if (c.d != NULL) {
    priv.elements[i].tag = TAG_RSA_PRIVATEEXPONENT;
    priv.elements[i].length = BN_num_bytes(c.d);
    INSIST(i < ARRAY_SIZE(bufs));
    bufs[i] = isc_mem_get(key->mctx, priv.elements[i].length);
    BN_bn2bin(c.d, bufs[i]);
    priv.elements[i].data = bufs[i];
    i++;
  }

  if (c.p != NULL) {
    priv.elements[i].tag = TAG_RSA_PRIME1;
    priv.elements[i].length = BN_num_bytes(c.p);
    INSIST(i < ARRAY_SIZE(bufs));
    bufs[i] = isc_mem_get(key->mctx, priv.elements[i].length);
    BN_bn2bin(c.p, bufs[i]);
    priv.elements[i].data = bufs[i];
    i++;
  }

  if (c.q != NULL) {
    priv.elements[i].tag = TAG_RSA_PRIME2;
    priv.elements[i].length = BN_num_bytes(c.q);
    INSIST(i < ARRAY_SIZE(bufs));
    bufs[i] = isc_mem_get(key->mctx, priv.elements[i].length);
    BN_bn2bin(c.q, bufs[i]);
    priv.elements[i].data = bufs[i];
    i++;
  }

  if (c.dmp1 != NULL) {
    priv.elements[i].tag = TAG_RSA_EXPONENT1;
    priv.elements[i].length = BN_num_bytes(c.dmp1);
    INSIST(i < ARRAY_SIZE(bufs));
    bufs[i] = isc_mem_get(key->mctx, priv.elements[i].length);
    BN_bn2bin(c.dmp1, bufs[i]);
    priv.elements[i].data = bufs[i];
    i++;
  }

  if (c.dmq1 != NULL) {
    priv.elements[i].tag = TAG_RSA_EXPONENT2;
    priv.elements[i].length = BN_num_bytes(c.dmq1);
    INSIST(i < ARRAY_SIZE(bufs));
    bufs[i] = isc_mem_get(key->mctx, priv.elements[i].length);
    BN_bn2bin(c.dmq1, bufs[i]);
    priv.elements[i].data = bufs[i];
    i++;
  }

  if (c.iqmp != NULL) {
    priv.elements[i].tag = TAG_RSA_COEFFICIENT;
    priv.elements[i].length = BN_num_bytes(c.iqmp);
    INSIST(i < ARRAY_SIZE(bufs));
    bufs[i] = isc_mem_get(key->mctx, priv.elements[i].length);
    BN_bn2bin(c.iqmp, bufs[i]);
    priv.elements[i].data = bufs[i];
    i++;
  }

  if (key->label != NULL) {
    priv.elements[i].tag = TAG_RSA_LABEL;
    priv.elements[i].length = (unsigned short)strlen(key->label) +
            1;
    priv.elements[i].data = (unsigned char *)key->label;
    i++;
  }

  priv.nelements = i;
  result = dst__privstruct_writefile(key, &priv, directory);

cleanup:
  for (i = 0; i < ARRAY_SIZE(bufs); i++) {
    if (bufs[i] != NULL) {
      isc_mem_put(key->mctx, bufs[i],
            priv.elements[i].length);
    }
  }
  isc_ossl_wrap_rsa_components_cleanup(&c);

  return result;
}

static isc_result_t
opensslrsa_fromlabel(dst_key_t *key, const char *label, const char *pin);

static isc_result_t
opensslrsa_parse(dst_key_t *key, isc_lex_t *lexer, dst_key_t *pub) {
  dst_private_t priv;
  isc_result_t result;
  int i;
  isc_mem_t *mctx = NULL;
  const char *label = NULL;
  EVP_PKEY *pkey = NULL;
  isc_ossl_wrap_rsa_components_t c = { .needs_cleanup = true };

  REQUIRE(key != NULL);
  REQUIRE(opensslrsa_valid_key_alg(key->key_alg));

  mctx = key->mctx;

  /* read private key file */
  CHECK(dst__privstruct_parse(key, DST_ALG_RSA, lexer, mctx, &priv));

  if (key->external) {
    if (priv.nelements != 0 || pub == NULL) {
      CLEANUP(DST_R_INVALIDPRIVATEKEY);
    }
    key->keydata.pkeypair.pub = pub->keydata.pkeypair.pub;
    key->keydata.pkeypair.priv = pub->keydata.pkeypair.priv;
    pub->keydata.pkeypair.pub = NULL;
    pub->keydata.pkeypair.priv = NULL;
    key->key_size = pub->key_size;
    CLEANUP(ISC_R_SUCCESS);
  }

  for (i = 0; i < priv.nelements; i++) {
    switch (priv.elements[i].tag) {
    case TAG_RSA_ENGINE:
      /* The Engine: tag is explicitly ignored */
      break;
    case TAG_RSA_LABEL:
      label = (char *)priv.elements[i].data;
      break;
    default:
      break;
    }
  }

  /*
   * Is this key stored in a HSM?
   * See if we can fetch it.
   */
  if (label != NULL) {
    CHECK(opensslrsa_fromlabel(key, label, NULL));
    /* Check that the public component matches if given */
    if (pub != NULL && EVP_PKEY_eq(key->keydata.pkeypair.pub,
                 pub->keydata.pkeypair.pub) != 1)
    {
      CLEANUP(DST_R_INVALIDPRIVATEKEY);
    }
    CLEANUP(ISC_R_SUCCESS);
  }

  for (i = 0; i < priv.nelements; i++) {
    BIGNUM *bn;
    switch (priv.elements[i].tag) {
    case TAG_RSA_ENGINE:
      continue;
    case TAG_RSA_LABEL:
      continue;
    default:
      bn = BN_bin2bn(priv.elements[i].data,
               priv.elements[i].length, NULL);
      if (bn == NULL) {
        CLEANUP(ISC_R_NOMEMORY);
      }
      switch (priv.elements[i].tag) {
      case TAG_RSA_MODULUS:
        c.n = bn;
        break;
      case TAG_RSA_PUBLICEXPONENT:
        c.e = bn;
        break;
      case TAG_RSA_PRIVATEEXPONENT:
        c.d = bn;
        break;
      case TAG_RSA_PRIME1:
        c.p = bn;
        break;
      case TAG_RSA_PRIME2:
        c.q = bn;
        break;
      case TAG_RSA_EXPONENT1:
        c.dmp1 = bn;
        break;
      case TAG_RSA_EXPONENT2:
        c.dmq1 = bn;
        break;
      case TAG_RSA_COEFFICIENT:
        c.iqmp = bn;
        break;
      default:
        BN_clear_free(bn);
      }
    }
  }

  /* Basic sanity check for public key portion */
  if (c.n == NULL || c.e == NULL) {
    CLEANUP(DST_R_INVALIDPRIVATEKEY);
  }
  if (BN_num_bits(c.n) < OPENSSLRSA_MIN_MODULUS_BITS ||
      BN_num_bits(c.n) > OPENSSLRSA_MAX_MODULUS_BITS)
  {
    CLEANUP(ISC_R_RANGE);
  }
  if (!rsa_exponent_in_range(c.e)) {
    CLEANUP(ISC_R_RANGE);
  }

  key->key_size = BN_num_bits(c.n);

  CHECK(isc_ossl_wrap_load_rsa_secret_from_components(&c, &pkey));

  /* Check that the public component matches if given */
  if (pub != NULL && EVP_PKEY_eq(pkey, pub->keydata.pkeypair.pub) != 1) {
    CLEANUP(DST_R_INVALIDPRIVATEKEY);
  }

  key->keydata.pkeypair.pub = pkey;
  key->keydata.pkeypair.priv = pkey;
  pkey = NULL;

cleanup:
  isc_ossl_wrap_rsa_components_cleanup(&c);
  EVP_PKEY_free(pkey);
  if (result != ISC_R_SUCCESS) {
    key->keydata.generic = NULL;
  }

  dst__privstruct_free(&priv, mctx);
  isc_safe_memwipe(&priv, sizeof(priv));

  return result;
}

static isc_result_t
opensslrsa_fromlabel(dst_key_t *key, const char *label, const char *pin) {
  EVP_PKEY *privpkey = NULL, *pubpkey = NULL;
  isc_result_t result;

  CHECK(dst__openssl_fromlabel(EVP_PKEY_RSA, label, pin, &pubpkey,
             &privpkey));

  if (!isc_ossl_wrap_rsa_exponent_is_allowed(pubpkey)) {
    CLEANUP(ISC_R_RANGE);
  }
  if (!isc_ossl_wrap_rsa_modulus_bits_in_range(
        pubpkey, OPENSSLRSA_MIN_MODULUS_BITS,
        OPENSSLRSA_MAX_MODULUS_BITS))
  {
    CLEANUP(ISC_R_RANGE);
  }

  key->label = isc_mem_strdup(key->mctx, label);
  key->key_size = EVP_PKEY_bits(privpkey);
  key->keydata.pkeypair.priv = privpkey;
  key->keydata.pkeypair.pub = pubpkey;
  privpkey = NULL;
  pubpkey = NULL;

cleanup:
  EVP_PKEY_free(privpkey);
  EVP_PKEY_free(pubpkey);
  return result;
}

static dst_func_t opensslrsa_functions = {
  .createctx = opensslrsa_createctx,
  .destroyctx = opensslrsa_destroyctx,
  .adddata = opensslrsa_adddata,
  .sign = opensslrsa_sign,
  .verify = opensslrsa_verify,
  .compare = dst__openssl_keypair_compare,
  .generate = opensslrsa_generate,
  .isprivate = dst__openssl_keypair_isprivate,
  .destroy = dst__openssl_keypair_destroy,
  .todns = opensslrsa_todns,
  .fromdns = opensslrsa_fromdns,
  .tofile = opensslrsa_tofile,
  .parse = opensslrsa_parse,
  .fromlabel = opensslrsa_fromlabel,
};

/*
 * An RSA public key with 2048 bits
 */
static const unsigned char e_bytes[] = "\x01\x00\x01";
static const unsigned char n_bytes[] =
  "\xc3\x90\x07\xbe\xf1\x85\xfc\x1a\x43\xb1\xa5\x15\xce\x71\x34\xfc\xc1"
  "\x87\x27\x28\x38\xa4\xcf\x7c\x1a\x82\xa8\xdc\x04\x14\xd0\x3f\xb4\xfe"
  "\x20\x4a\xdd\xd9\x0d\xd7\xcd\x61\x8c\xbd\x61\xa8\x10\xb5\x63\x1c\x29"
  "\x15\xcb\x41\xee\x43\x91\x7f\xeb\xa5\x2c\xab\x81\x75\x0d\xa3\x3d\xe4"
  "\xc8\x49\xb9\xca\x5a\x55\xa1\xbb\x09\xd1\xfb\xcd\xa2\xd2\x12\xa4\x85"
  "\xdf\xa5\x65\xc9\x27\x2d\x8b\xd7\x8b\xfe\x6d\xc4\xd1\xd9\x83\x1c\x91"
  "\x7d\x3d\xd0\xa4\xcd\xe1\xe7\xb9\x7a\x11\x38\xf9\x8b\x3c\xec\x30\xb6"
  "\x36\xb9\x92\x64\x81\x56\x3c\xbc\xf9\x49\xfb\xba\x82\xb7\xa0\xfa\x65"
  "\x79\x83\xb9\x4c\xa7\xfd\x53\x0b\x5a\xe4\xde\xf9\xfc\x38\x7e\xb5\x2c"
  "\xa0\xc3\xb2\xfc\x7c\x38\xb0\x63\x50\xaf\x00\xaa\xb2\xad\x49\x54\x1e"
  "\x8b\x11\x88\x9b\x6e\xae\x3b\x23\xa3\xdd\x53\x51\x80\x7a\x0b\x91\x4e"
  "\x6d\x32\x01\xbd\x17\x81\x12\x64\x9f\x84\xae\x76\x53\x1a\x63\xa0\xda"
  "\xcc\x45\x04\x72\xb0\xa7\xfb\xfa\x02\x39\x53\xc1\x83\x1f\x88\x54\x47"
  "\x88\x63\x20\x71\x5d\xe2\xaa\x7c\x53\x39\x5e\x35\x25\xee\xe6\x5c\x15"
  "\x5e\x14\xbe\x99\xde\x25\x19\xe7\x13\xdb\xce\xa3\xd3\x6c\x5c\xbb\x0e"
  "\x6b";

static const unsigned char sha1_sig[] =
  "\x69\x99\x89\x28\xe0\x38\x34\x91\x29\xb6\xac\x4b\xe9\x51\xbd\xbe\xc8"
  "\x1a\x2d\xb6\xca\x99\xa3\x9f\x6a\x8b\x94\x5a\x51\x37\xd5\x8d\xae\x87"
  "\xed\xbc\x8e\xb8\xa3\x60\x6b\xf6\xe6\x72\xfc\x26\x2a\x39\x2b\xfe\x88"
  "\x1a\xa9\xd1\x93\xc7\xb9\xf8\xb6\x45\xa1\xf9\xa1\x56\x78\x7b\x00\xec"
  "\x33\x83\xd4\x93\x25\x48\xb3\x50\x09\xd0\xbc\x7f\xac\x67\xc7\xa2\x7f"
  "\xfc\xf6\x5a\xef\xf8\x5a\xad\x52\x74\xf5\x71\x34\xd9\x3d\x33\x8b\x4d"
  "\x99\x64\x7e\x14\x59\xbe\xdf\x26\x8a\x67\x96\x6c\x1f\x79\x85\x10\x0d"
  "\x7f\xd6\xa4\xba\x57\x41\x03\x71\x4e\x8c\x17\xd5\xc4\xfb\x4a\xbe\x66"
  "\x45\x15\x45\x0c\x02\xe0\x10\xe1\xbb\x33\x8d\x90\x34\x3c\x94\xa4\x4c"
  "\x7c\xd0\x5e\x90\x76\x80\x59\xb2\xfa\x54\xbf\xa9\x86\xb8\x84\x1e\x28"
  "\x48\x60\x2f\x9e\xa4\xbc\xd4\x9c\x20\x27\x16\xac\x33\xcb\xcf\xab\x93"
  "\x7a\x3b\x74\xa0\x18\x92\xa1\x4f\xfc\x52\x19\xee\x7a\x13\x73\xba\x36"
  "\xaf\x78\x5d\xb6\x1f\x96\x76\x15\x73\xee\x04\xa8\x70\x27\xf7\xe7\xfa"
  "\xe8\xf6\xc8\x5f\x4a\x81\x56\x0a\x94\xf3\xc6\x98\xd2\x93\xc4\x0b\x49"
  "\x6b\x44\xd3\x73\xa2\xe3\xef\x5d\x9e\x68\xac\xa7\x42\xb1\xbb\x65\xbe"
  "\x59";

static const unsigned char sha256_sig[] =
  "\x0f\x8c\xdb\xe6\xb6\x21\xc8\xc5\x28\x76\x7d\xf6\xf2\x3b\x78\x47\x77"
  "\x03\x34\xc5\x5e\xc0\xda\x42\x41\xc0\x0f\x97\xd3\xd0\x53\xa1\xd6\x87"
  "\xe4\x16\x29\x9a\xa5\x59\xf4\x01\xad\xc9\x04\xe7\x61\xe2\xcb\x79\x73"
  "\xce\xe0\xa6\x85\xe5\x10\x8c\x4b\xc5\x68\x3b\x96\x42\x3f\x56\xb3\x6d"
  "\x89\xc4\xff\x72\x36\xf2\x3f\xed\xe9\xb8\xe3\xae\xab\x3c\xb7\xaa\xf7"
  "\x1f\x8f\x26\x6b\xee\xc1\xac\x72\x89\x23\x8b\x7a\xd7\x8c\x84\xf3\xf5"
  "\x97\xa8\x8d\xd3\xef\xb2\x5e\x06\x04\x21\xdd\x28\xa2\x28\x83\x68\x9b"
  "\xac\x34\xdd\x36\x33\xda\xdd\xa4\x59\xc7\x5a\x4d\xf3\x83\x06\xd5\xc0"
  "\x0d\x1f\x4f\x47\x2f\x9f\xcc\xc2\x0d\x21\x1e\x82\xb9\x3d\xf3\xa4\x1a"
  "\xa6\xd8\x0e\x72\x1d\x71\x17\x1c\x54\xad\x37\x3e\xa4\x0e\x70\x86\x53"
  "\xfb\x40\xad\xb9\x14\xf8\x8d\x93\xbb\xd7\xe7\x31\xce\xe0\x98\xda\x27"
  "\x1c\x18\x8e\xd8\x85\xcb\xa7\xb1\x18\xac\x8c\xa8\x9d\xa9\xe2\xf6\x30"
  "\x95\xa4\x81\xf4\x1c\xa0\x31\xd5\xc7\x9d\x28\x33\xee\x7f\x08\x4f\xcb"
  "\xd1\x14\x17\xdf\xd0\x88\x78\x47\x29\xaf\x6c\xb2\x62\xa6\x30\x87\x29"
  "\xaa\x80\x19\x7d\x2f\x05\xe3\x7e\x23\x73\x88\x08\xcc\xbd\x50\x46\x09"
  "\x2a";

static const unsigned char sha512_sig[] =
  "\x15\xda\x87\x87\x1f\x76\x08\xd3\x9d\x3a\xb9\xd2\x6a\x0e\x3b\x7d\xdd"
  "\xec\x7d\xc4\x6d\x26\xf5\x04\xd3\x76\xc7\x83\xc4\x81\x69\x35\xe9\x47"
  "\xbf\x49\xd1\xc0\xf9\x01\x4e\x0a\x34\x5b\xd0\xec\x6e\xe2\x2e\xe9\x2d"
  "\x00\xfd\xe0\xa0\x28\x54\x53\x19\x49\x6d\xd2\x58\xb9\x47\xfa\x45\xad"
  "\xd2\x1d\x52\xac\x80\xcb\xfc\x91\x97\x84\x58\x5f\xab\x21\x62\x60\x79"
  "\xb8\x8a\x83\xe1\xf1\xcb\x05\x4c\x92\x56\x62\xd9\xbf\xa7\x81\x34\x23"
  "\xdf\xd7\xa7\xc4\xdf\xde\x96\x00\x57\x4b\x78\x85\xb9\x3b\xdd\x3f\x98"
  "\x88\x59\x1d\x48\xcf\x5a\xa8\xb7\x2a\x8b\x77\x93\x8e\x38\x3a\x0c\xa7"
  "\x8a\x5f\xe6\x9f\xcb\xf0\x9a\x6b\xb6\x91\x04\x8b\x69\x6a\x37\xee\xa2"
  "\xad\x5f\x31\x20\x96\xd6\x51\x80\xbf\x62\x48\xb8\xe4\x94\x10\x86\x4e"
  "\xf2\x22\x1e\xa4\xd5\x54\xfe\xe1\x35\x49\xaf\xf8\x62\xfc\x11\xeb\xf7"
  "\x3d\xd5\x5e\xaf\x11\xbd\x3d\xa9\x3a\x9f\x7f\xe8\xb4\x0d\xa2\xbb\x1c"
  "\xbd\x4c\xed\x9e\x81\xb1\xec\xd3\xea\xaa\x03\xe3\x14\xdf\x8c\xb3\x78"
  "\x85\x5e\x87\xad\xec\x41\x1a\xa9\x4f\xd2\xe6\xc6\xbe\xfa\xb8\x10\xea"
  "\x74\x25\x36\x0c\x23\xe2\x24\xb7\x21\xb7\x0d\xaf\xf6\xb4\x31\xf5\x75"
  "\xf1";

static isc_result_t
check_algorithm(unsigned short algorithm) {
  isc_ossl_wrap_rsa_components_t c = { .needs_cleanup = true };
  EVP_MD_CTX *evp_md_ctx = EVP_MD_CTX_create();
  EVP_PKEY *pkey = NULL;
  const EVP_MD *type = NULL;
  const unsigned char *sig = NULL;
  isc_result_t result = ISC_R_SUCCESS;
  size_t len;

  switch (algorithm) {
  case DST_ALG_RSASHA1:
  case DST_ALG_NSEC3RSASHA1:
    type = isc__crypto_md[ISC_MD_SHA1]; /* SHA1 + RSA */
    sig = sha1_sig;
    len = sizeof(sha1_sig) - 1;
    break;
  case DST_ALG_RSASHA256:
  case DST_ALG_RSASHA256PRIVATEOID:
    type = isc__crypto_md[ISC_MD_SHA256]; /* SHA256 + RSA */
    sig = sha256_sig;
    len = sizeof(sha256_sig) - 1;
    break;
  case DST_ALG_RSASHA512:
  case DST_ALG_RSASHA512PRIVATEOID:
    type = isc__crypto_md[ISC_MD_SHA512];
    sig = sha512_sig;
    len = sizeof(sha512_sig) - 1;
    break;
  default:
    CLEANUP(ISC_R_NOTIMPLEMENTED);
  }

  /*
   * Construct pkey.
   */
  c.e = BN_bin2bn(e_bytes, sizeof(e_bytes) - 1, NULL);
  c.n = BN_bin2bn(n_bytes, sizeof(n_bytes) - 1, NULL);

  result = isc_ossl_wrap_load_rsa_public_from_components(&c, &pkey);
  INSIST(result == ISC_R_SUCCESS);

  /*
   * Check that we can verify the signature.
   */
  if (EVP_DigestInit_ex(evp_md_ctx, type, NULL) != 1 ||
      EVP_DigestUpdate(evp_md_ctx, "test", 4) != 1 ||
      EVP_VerifyFinal(evp_md_ctx, sig, len, pkey) != 1)
  {
    CLEANUP(ISC_R_NOTIMPLEMENTED);
  }

cleanup:
  isc_ossl_wrap_rsa_components_cleanup(&c);
  EVP_PKEY_free(pkey);
  EVP_MD_CTX_destroy(evp_md_ctx);
  ERR_clear_error();
  return result;
}

void
dst__opensslrsa_init(dst_func_t **funcp, unsigned short algorithm) {
  REQUIRE(funcp != NULL);

  if (*funcp == NULL) {
    if (check_algorithm(algorithm) == ISC_R_SUCCESS) {
      *funcp = &opensslrsa_functions;
    }
  }

  if (rsa_exponent_min == NULL) {
    rsa_exponent_min = BN_new();
    INSIST(rsa_exponent_min != NULL);

    RUNTIME_CHECK(BN_set_word(rsa_exponent_min, 3) == 1);
  }

  if (rsa_exponent_max == NULL) {
    rsa_exponent_max = BN_new();
    INSIST(rsa_exponent_max != NULL);

    RUNTIME_CHECK(BN_set_bit(rsa_exponent_max, 0) == 1);
    RUNTIME_CHECK(BN_set_bit(rsa_exponent_max, 32) == 1);
  }
}

void
dst__opensslrsa_shutdown(void) {
  REQUIRE(rsa_exponent_min != NULL);
  REQUIRE(rsa_exponent_max != NULL);

  BN_free(rsa_exponent_min);
  BN_free(rsa_exponent_max);
}

Coverage Report

Created: 2026-06-09 06:11