/src/unbound/validator/val_secalgo.c

Source
/*
 * validator/val_secalgo.c - validator security algorithm functions.
 *
 * Copyright (c) 2012, NLnet Labs. All rights reserved.
 *
 * This software is open source.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of the NLNET LABS nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * \file
 *
 * This file contains helper functions for the validator module.
 * These functions take raw data buffers, formatted for crypto verification,
 * and do the library calls (for the crypto library in use).
 */
#include "config.h"
/* packed_rrset on top to define enum types (forced by c99 standard) */
#include "util/data/packed_rrset.h"
#include "validator/val_secalgo.h"
#include "validator/val_nsec3.h"
#include "util/log.h"
#include "sldns/rrdef.h"
#include "sldns/keyraw.h"
#include "sldns/sbuffer.h"

#if !defined(HAVE_SSL) && !defined(HAVE_NSS) && !defined(HAVE_NETTLE)
#error "Need crypto library to do digital signature cryptography"
#endif

/** fake DSA support for unit tests */
int fake_dsa = 0;
/** fake SHA1 support for unit tests */
int fake_sha1 = 0;

/* OpenSSL implementation */
#ifdef HAVE_SSL
#ifdef HAVE_OPENSSL_ERR_H
#include <openssl/err.h>
#endif

#ifdef HAVE_OPENSSL_RAND_H
#include <openssl/rand.h>
#endif

#ifdef HAVE_OPENSSL_CONF_H
#include <openssl/conf.h>
#endif

#ifdef HAVE_OPENSSL_ENGINE_H
#include <openssl/engine.h>
#endif

#if defined(HAVE_OPENSSL_DSA_H) && defined(USE_DSA)
#include <openssl/dsa.h>
#endif

/**
 * Output a libcrypto openssl error to the logfile.
 * @param str: string to add to it.
 * @param e: the error to output, error number from ERR_get_error().
 */
static void
log_crypto_error(const char* str, unsigned long e)
{
  char buf[128];
  /* or use ERR_error_string if ERR_error_string_n is not avail TODO */
  ERR_error_string_n(e, buf, sizeof(buf));
  /* buf now contains */
  /* error:[error code]:[library name]:[function name]:[reason string] */
  log_err("%s crypto %s", str, buf);
}

/**
 * Output a libcrypto openssl error to the logfile as a debug message.
 * @param level: debug level to use in verbose() call
 * @param str: string to add to it.
 * @param e: the error to output, error number from ERR_get_error().
 */
static void
log_crypto_verbose(enum verbosity_value level, const char* str, unsigned long e)
{
  char buf[128];
  /* or use ERR_error_string if ERR_error_string_n is not avail TODO */
  ERR_error_string_n(e, buf, sizeof(buf));
  /* buf now contains */
  /* error:[error code]:[library name]:[function name]:[reason string] */
  verbose(level, "%s crypto %s", str, buf);
}

/* return size of digest if supported, or 0 otherwise */
size_t
nsec3_hash_algo_size_supported(int id)
{
  switch(id) {
  case NSEC3_HASH_SHA1:
    return SHA_DIGEST_LENGTH;
  default:
    return 0;
  }
}

/* perform nsec3 hash. return false on failure */
int
secalgo_nsec3_hash(int algo, unsigned char* buf, size_t len,
        unsigned char* res)
{
  switch(algo) {
  case NSEC3_HASH_SHA1:
#ifdef OPENSSL_FIPS
    if(!sldns_digest_evp(buf, len, res, EVP_sha1()))
      log_crypto_error("could not digest with EVP_sha1",
        ERR_get_error());
#else
    (void)SHA1(buf, len, res);
#endif
    return 1;
  default:
    return 0;
  }
}

void
secalgo_hash_sha256(unsigned char* buf, size_t len, unsigned char* res)
{
#ifdef OPENSSL_FIPS
  if(!sldns_digest_evp(buf, len, res, EVP_sha256()))
    log_crypto_error("could not digest with EVP_sha256",
      ERR_get_error());
#else
  (void)SHA256(buf, len, res);
#endif
}

/** hash structure for keeping track of running hashes */
struct secalgo_hash {
  /** the openssl message digest context */
  EVP_MD_CTX* ctx;
};

/** create secalgo hash with hash type */
static struct secalgo_hash* secalgo_hash_create_md(const EVP_MD* md)
{
  struct secalgo_hash* h;
  if(!md)
    return NULL;
  h = calloc(1, sizeof(*h));
  if(!h)
    return NULL;
  h->ctx = EVP_MD_CTX_create();
  if(!h->ctx) {
    free(h);
    return NULL;
  }
  if(!EVP_DigestInit_ex(h->ctx, md, NULL)) {
    EVP_MD_CTX_destroy(h->ctx);
    free(h);
    return NULL;
  }
  return h;
}

struct secalgo_hash* secalgo_hash_create_sha384(void)
{
  return secalgo_hash_create_md(EVP_sha384());
}

struct secalgo_hash* secalgo_hash_create_sha512(void)
{
  return secalgo_hash_create_md(EVP_sha512());
}

int secalgo_hash_update(struct secalgo_hash* hash, uint8_t* data, size_t len)
{
  return EVP_DigestUpdate(hash->ctx, (unsigned char*)data,
    (unsigned int)len);
}

int secalgo_hash_final(struct secalgo_hash* hash, uint8_t* result,
        size_t maxlen, size_t* resultlen)
{
  if(EVP_MD_CTX_size(hash->ctx) > (int)maxlen) {
    *resultlen = 0;
    log_err("secalgo_hash_final: hash buffer too small");
    return 0;
  }
  *resultlen = EVP_MD_CTX_size(hash->ctx);
  return EVP_DigestFinal_ex(hash->ctx, result, NULL);
}

void secalgo_hash_delete(struct secalgo_hash* hash)
{
  if(!hash) return;
  EVP_MD_CTX_destroy(hash->ctx);
  free(hash);
}

/**
 * Return size of DS digest according to its hash algorithm.
 * @param algo: DS digest algo.
 * @return size in bytes of digest, or 0 if not supported.
 */
size_t
ds_digest_size_supported(int algo)
{
  switch(algo) {
    case LDNS_SHA1:
#if defined(HAVE_EVP_SHA1) && defined(USE_SHA1)
#ifdef HAVE_EVP_DEFAULT_PROPERTIES_IS_FIPS_ENABLED
      if (EVP_default_properties_is_fips_enabled(NULL))
        return 0;
#endif
      return SHA_DIGEST_LENGTH;
#else
      if(fake_sha1) return 20;
      return 0;
#endif
#ifdef HAVE_EVP_SHA256
    case LDNS_SHA256:
      return SHA256_DIGEST_LENGTH;
#endif
#ifdef USE_GOST
    case LDNS_HASH_GOST:
      /* we support GOST if it can be loaded */
      (void)sldns_key_EVP_load_gost_id();
      if(EVP_get_digestbyname("md_gost94"))
        return 32;
      else  return 0;
#endif
#ifdef USE_ECDSA
    case LDNS_SHA384:
      return SHA384_DIGEST_LENGTH;
#endif
    default: break;
  }
  return 0;
}

#ifdef USE_GOST
/** Perform GOST hash */
static int
do_gost94(unsigned char* data, size_t len, unsigned char* dest)
{
  const EVP_MD* md = EVP_get_digestbyname("md_gost94");
  if(!md) 
    return 0;
  return sldns_digest_evp(data, (unsigned int)len, dest, md);
}
#endif

int
secalgo_ds_digest(int algo, unsigned char* buf, size_t len,
  unsigned char* res)
{
  switch(algo) {
#if defined(HAVE_EVP_SHA1) && defined(USE_SHA1)
    case LDNS_SHA1:
#ifdef OPENSSL_FIPS
      if(!sldns_digest_evp(buf, len, res, EVP_sha1()))
        log_crypto_error("could not digest with EVP_sha1",
          ERR_get_error());
#else
      (void)SHA1(buf, len, res);
#endif
      return 1;
#endif
#ifdef HAVE_EVP_SHA256
    case LDNS_SHA256:
#ifdef OPENSSL_FIPS
      if(!sldns_digest_evp(buf, len, res, EVP_sha256()))
        log_crypto_error("could not digest with EVP_sha256",
          ERR_get_error());
#else
      (void)SHA256(buf, len, res);
#endif
      return 1;
#endif
#ifdef USE_GOST
    case LDNS_HASH_GOST:
      if(do_gost94(buf, len, res))
        return 1;
      break;
#endif
#ifdef USE_ECDSA
    case LDNS_SHA384:
#ifdef OPENSSL_FIPS
      if(!sldns_digest_evp(buf, len, res, EVP_sha384()))
        log_crypto_error("could not digest with EVP_sha384",
          ERR_get_error());
#else
      (void)SHA384(buf, len, res);
#endif
      return 1;
#endif
    default: 
      verbose(VERB_QUERY, "unknown DS digest algorithm %d", 
        algo);
      break;
  }
  return 0;
}

/** return true if DNSKEY algorithm id is supported */
int
dnskey_algo_id_is_supported(int id)
{
  switch(id) {
  case LDNS_RSAMD5:
    /* RFC 6725 deprecates RSAMD5 */
    return 0;
  case LDNS_DSA:
  case LDNS_DSA_NSEC3:
#if defined(USE_DSA) && defined(USE_SHA1)
    return 1;
#else
    if(fake_dsa || fake_sha1) return 1;
    return 0;
#endif

  case LDNS_RSASHA1:
  case LDNS_RSASHA1_NSEC3:
#ifdef USE_SHA1
#ifdef HAVE_EVP_DEFAULT_PROPERTIES_IS_FIPS_ENABLED
    return !EVP_default_properties_is_fips_enabled(NULL);
#else
    return 1;
#endif
#else
    if(fake_sha1) return 1;
    return 0;
#endif

#if defined(HAVE_EVP_SHA256) && defined(USE_SHA2)
  case LDNS_RSASHA256:
#endif
#if defined(HAVE_EVP_SHA512) && defined(USE_SHA2)
  case LDNS_RSASHA512:
#endif
#ifdef USE_ECDSA
  case LDNS_ECDSAP256SHA256:
  case LDNS_ECDSAP384SHA384:
#endif
#if (defined(HAVE_EVP_SHA256) && defined(USE_SHA2)) || (defined(HAVE_EVP_SHA512) && defined(USE_SHA2)) || defined(USE_ECDSA)
    return 1;
#endif
#ifdef USE_ED25519
  case LDNS_ED25519:
#endif
#ifdef USE_ED448
  case LDNS_ED448:
#endif
#if defined(USE_ED25519) || defined(USE_ED448)
#ifdef HAVE_EVP_DEFAULT_PROPERTIES_IS_FIPS_ENABLED
    return !EVP_default_properties_is_fips_enabled(NULL);
#else
    return 1;
#endif
#endif

#ifdef USE_GOST
  case LDNS_ECC_GOST:
    /* we support GOST if it can be loaded */
    return sldns_key_EVP_load_gost_id();
#endif
  default:
    return 0;
  }
}

#ifdef USE_DSA
/**
 * Setup DSA key digest in DER encoding ... 
 * @param sig: input is signature output alloced ptr (unless failure).
 *  caller must free alloced ptr if this routine returns true.
 * @param len: input is initial siglen, output is output len.
 * @return false on failure.
 */
static int
setup_dsa_sig(unsigned char** sig, unsigned int* len)
{
  unsigned char* orig = *sig;
  unsigned int origlen = *len;
  int newlen;
  BIGNUM *R, *S;
  DSA_SIG *dsasig;

  /* extract the R and S field from the sig buffer */
  if(origlen < 1 + 2*SHA_DIGEST_LENGTH)
    return 0;
  R = BN_new();
  if(!R) return 0;
  (void) BN_bin2bn(orig + 1, SHA_DIGEST_LENGTH, R);
  S = BN_new();
  if(!S) return 0;
  (void) BN_bin2bn(orig + 21, SHA_DIGEST_LENGTH, S);
  dsasig = DSA_SIG_new();
  if(!dsasig) return 0;

#ifdef HAVE_DSA_SIG_SET0
  if(!DSA_SIG_set0(dsasig, R, S)) {
    DSA_SIG_free(dsasig);
    return 0;
  }
#else
#  ifndef S_SPLINT_S
  dsasig->r = R;
  dsasig->s = S;
#  endif /* S_SPLINT_S */
#endif
  *sig = NULL;
  newlen = i2d_DSA_SIG(dsasig, sig);
  if(newlen < 0) {
    DSA_SIG_free(dsasig);
    free(*sig);
    return 0;
  }
  *len = (unsigned int)newlen;
  DSA_SIG_free(dsasig);
  return 1;
}
#endif /* USE_DSA */

#ifdef USE_ECDSA
/**
 * Setup the ECDSA signature in its encoding that the library wants.
 * Converts from plain numbers to ASN formatted.
 * @param sig: input is signature, output alloced ptr (unless failure).
 *  caller must free alloced ptr if this routine returns true.
 * @param len: input is initial siglen, output is output len.
 * @return false on failure.
 */
static int
setup_ecdsa_sig(unsigned char** sig, unsigned int* len)
{
        /* convert from two BIGNUMs in the rdata buffer, to ASN notation.
   * ASN preamble: 30440220 <R 32bytefor256> 0220 <S 32bytefor256>
   * the '20' is the length of that field (=bnsize).
i  * the '44' is the total remaining length.
   * if negative, start with leading zero.
   * if starts with 00s, remove them from the number.
   */
        uint8_t pre[] = {0x30, 0x44, 0x02, 0x20};
        int pre_len = 4;
        uint8_t mid[] = {0x02, 0x20};
        int mid_len = 2;
        int raw_sig_len, r_high, s_high, r_rem=0, s_rem=0;
  int bnsize = (int)((*len)/2);
        unsigned char* d = *sig;
  uint8_t* p;
  /* if too short or not even length, fails */
  if(*len < 16 || bnsize*2 != (int)*len)
    return 0;

        /* strip leading zeroes from r (but not last one) */
        while(r_rem < bnsize-1 && d[r_rem] == 0)
                r_rem++;
        /* strip leading zeroes from s (but not last one) */
        while(s_rem < bnsize-1 && d[bnsize+s_rem] == 0)
                s_rem++;

        r_high = ((d[0+r_rem]&0x80)?1:0);
        s_high = ((d[bnsize+s_rem]&0x80)?1:0);
        raw_sig_len = pre_len + r_high + bnsize - r_rem + mid_len +
                s_high + bnsize - s_rem;
  *sig = (unsigned char*)malloc((size_t)raw_sig_len);
  if(!*sig)
    return 0;
  p = (uint8_t*)*sig;
  p[0] = pre[0];
  p[1] = (uint8_t)(raw_sig_len-2);
  p[2] = pre[2];
  p[3] = (uint8_t)(bnsize + r_high - r_rem);
  p += 4;
  if(r_high) {
    *p = 0;
    p += 1;
  }
  memmove(p, d+r_rem, (size_t)bnsize-r_rem);
  p += bnsize-r_rem;
  memmove(p, mid, (size_t)mid_len-1);
  p += mid_len-1;
  *p = (uint8_t)(bnsize + s_high - s_rem);
  p += 1;
        if(s_high) {
    *p = 0;
    p += 1;
  }
  memmove(p, d+bnsize+s_rem, (size_t)bnsize-s_rem);
  *len = (unsigned int)raw_sig_len;
  return 1;
}
#endif /* USE_ECDSA */

#ifdef USE_ECDSA_EVP_WORKAROUND
static EVP_MD ecdsa_evp_256_md;
static EVP_MD ecdsa_evp_384_md;
void ecdsa_evp_workaround_init(void)
{
  /* openssl before 1.0.0 fixes RSA with the SHA256
   * hash in EVP.  We create one for ecdsa_sha256 */
  ecdsa_evp_256_md = *EVP_sha256();
  ecdsa_evp_256_md.required_pkey_type[0] = EVP_PKEY_EC;
  ecdsa_evp_256_md.verify = (void*)ECDSA_verify;

  ecdsa_evp_384_md = *EVP_sha384();
  ecdsa_evp_384_md.required_pkey_type[0] = EVP_PKEY_EC;
  ecdsa_evp_384_md.verify = (void*)ECDSA_verify;
}
#endif /* USE_ECDSA_EVP_WORKAROUND */

/**
 * Setup key and digest for verification. Adjust sig if necessary.
 *
 * @param algo: key algorithm
 * @param evp_key: EVP PKEY public key to create.
 * @param digest_type: digest type to use
 * @param key: key to setup for.
 * @param keylen: length of key.
 * @return false on failure.
 */
static int
setup_key_digest(int algo, EVP_PKEY** evp_key, const EVP_MD** digest_type, 
  unsigned char* key, size_t keylen)
{
  switch(algo) {
#if defined(USE_DSA) && defined(USE_SHA1)
    case LDNS_DSA:
    case LDNS_DSA_NSEC3:
      *evp_key = sldns_key_dsa2pkey_raw(key, keylen);
      if(!*evp_key) {
        verbose(VERB_QUERY, "verify: sldns_key_dsa2pkey failed");
        return 0;
      }
#ifdef HAVE_EVP_DSS1
      *digest_type = EVP_dss1();
#else
      *digest_type = EVP_sha1();
#endif

      break;
#endif /* USE_DSA && USE_SHA1 */

#if defined(USE_SHA1) || (defined(HAVE_EVP_SHA256) && defined(USE_SHA2)) || (defined(HAVE_EVP_SHA512) && defined(USE_SHA2))
#ifdef USE_SHA1
    case LDNS_RSASHA1:
    case LDNS_RSASHA1_NSEC3:
#endif
#if defined(HAVE_EVP_SHA256) && defined(USE_SHA2)
    case LDNS_RSASHA256:
#endif
#if defined(HAVE_EVP_SHA512) && defined(USE_SHA2)
    case LDNS_RSASHA512:
#endif
      *evp_key = sldns_key_rsa2pkey_raw(key, keylen);
      if(!*evp_key) {
        verbose(VERB_QUERY, "verify: sldns_key_rsa2pkey SHA failed");
        return 0;
      }

      /* select SHA version */
#if defined(HAVE_EVP_SHA256) && defined(USE_SHA2)
      if(algo == LDNS_RSASHA256)
        *digest_type = EVP_sha256();
      else
#endif
#if defined(HAVE_EVP_SHA512) && defined(USE_SHA2)
        if(algo == LDNS_RSASHA512)
        *digest_type = EVP_sha512();
      else
#endif
#ifdef USE_SHA1
        *digest_type = EVP_sha1();
#else
        { verbose(VERB_QUERY, "no digest available"); return 0; }
#endif
      break;
#endif /* defined(USE_SHA1) || (defined(HAVE_EVP_SHA256) && defined(USE_SHA2)) || (defined(HAVE_EVP_SHA512) && defined(USE_SHA2)) */

    case LDNS_RSAMD5:
      *evp_key = sldns_key_rsa2pkey_raw(key, keylen);
      if(!*evp_key) {
        verbose(VERB_QUERY, "verify: sldns_key_rsa2pkey MD5 failed");
        return 0;
      }
      *digest_type = EVP_md5();

      break;
#ifdef USE_GOST
    case LDNS_ECC_GOST:
      *evp_key = sldns_gost2pkey_raw(key, keylen);
      if(!*evp_key) {
        verbose(VERB_QUERY, "verify: "
          "sldns_gost2pkey_raw failed");
        return 0;
      }
      *digest_type = EVP_get_digestbyname("md_gost94");
      if(!*digest_type) {
        verbose(VERB_QUERY, "verify: "
          "EVP_getdigest md_gost94 failed");
        return 0;
      }
      break;
#endif
#ifdef USE_ECDSA
    case LDNS_ECDSAP256SHA256:
      *evp_key = sldns_ecdsa2pkey_raw(key, keylen,
        LDNS_ECDSAP256SHA256);
      if(!*evp_key) {
        verbose(VERB_QUERY, "verify: "
          "sldns_ecdsa2pkey_raw failed");
        return 0;
      }
#ifdef USE_ECDSA_EVP_WORKAROUND
      *digest_type = &ecdsa_evp_256_md;
#else
      *digest_type = EVP_sha256();
#endif
      break;
    case LDNS_ECDSAP384SHA384:
      *evp_key = sldns_ecdsa2pkey_raw(key, keylen,
        LDNS_ECDSAP384SHA384);
      if(!*evp_key) {
        verbose(VERB_QUERY, "verify: "
          "sldns_ecdsa2pkey_raw failed");
        return 0;
      }
#ifdef USE_ECDSA_EVP_WORKAROUND
      *digest_type = &ecdsa_evp_384_md;
#else
      *digest_type = EVP_sha384();
#endif
      break;
#endif /* USE_ECDSA */
#ifdef USE_ED25519
    case LDNS_ED25519:
      *evp_key = sldns_ed255192pkey_raw(key, keylen);
      if(!*evp_key) {
        verbose(VERB_QUERY, "verify: "
          "sldns_ed255192pkey_raw failed");
        return 0;
      }
      *digest_type = NULL;
      break;
#endif /* USE_ED25519 */
#ifdef USE_ED448
    case LDNS_ED448:
      *evp_key = sldns_ed4482pkey_raw(key, keylen);
      if(!*evp_key) {
        verbose(VERB_QUERY, "verify: "
          "sldns_ed4482pkey_raw failed");
        return 0;
      }
      *digest_type = NULL;
      break;
#endif /* USE_ED448 */
    default:
      verbose(VERB_QUERY, "verify: unknown algorithm %d", 
        algo);
      return 0;
  }
  return 1;
}

static void
digest_ctx_free(EVP_MD_CTX* ctx, EVP_PKEY *evp_key,
  unsigned char* sigblock, int dofree, int docrypto_free)
{
#ifdef HAVE_EVP_MD_CTX_NEW
  EVP_MD_CTX_destroy(ctx);
#else
  EVP_MD_CTX_cleanup(ctx);
  free(ctx);
#endif
  EVP_PKEY_free(evp_key);
  if(dofree) free(sigblock);
  else if(docrypto_free) OPENSSL_free(sigblock);
}

static enum sec_status
digest_error_status(const char *str)
{
  unsigned long e = ERR_get_error();
#ifdef EVP_R_INVALID_DIGEST
  if (ERR_GET_LIB(e) == ERR_LIB_EVP &&
    ERR_GET_REASON(e) == EVP_R_INVALID_DIGEST) {
    log_crypto_verbose(VERB_ALGO, str, e);
    return sec_status_indeterminate;
  }
#endif
  log_crypto_verbose(VERB_QUERY, str, e);
  return sec_status_unchecked;
}

/**
 * Check a canonical sig+rrset and signature against a dnskey
 * @param buf: buffer with data to verify, the first rrsig part and the
 *  canonicalized rrset.
 * @param algo: DNSKEY algorithm.
 * @param sigblock: signature rdata field from RRSIG
 * @param sigblock_len: length of sigblock data.
 * @param key: public key data from DNSKEY RR.
 * @param keylen: length of keydata.
 * @param reason: bogus reason in more detail.
 * @return secure if verification succeeded, bogus on crypto failure,
 *  unchecked on format errors and alloc failures, indeterminate
 *  if digest is not supported by the crypto library (openssl3+ only).
 */
enum sec_status
verify_canonrrset(sldns_buffer* buf, int algo, unsigned char* sigblock,
  unsigned int sigblock_len, unsigned char* key, unsigned int keylen,
  char** reason)
{
  const EVP_MD *digest_type;
  EVP_MD_CTX* ctx;
  int res, dofree = 0, docrypto_free = 0;
  EVP_PKEY *evp_key = NULL;

#ifndef USE_DSA
  if((algo == LDNS_DSA || algo == LDNS_DSA_NSEC3) &&(fake_dsa||fake_sha1))
    return sec_status_secure;
#endif
#ifndef USE_SHA1
  if(fake_sha1 && (algo == LDNS_DSA || algo == LDNS_DSA_NSEC3 || algo == LDNS_RSASHA1 || algo == LDNS_RSASHA1_NSEC3))
    return sec_status_secure;
#endif
  
  if(!setup_key_digest(algo, &evp_key, &digest_type, key, keylen)) {
    verbose(VERB_QUERY, "verify: failed to setup key");
    *reason = "use of key for crypto failed";
    EVP_PKEY_free(evp_key);
    return sec_status_bogus;
  }
#ifdef USE_DSA
  /* if it is a DSA signature in bind format, convert to DER format */
  if((algo == LDNS_DSA || algo == LDNS_DSA_NSEC3) && 
    sigblock_len == 1+2*SHA_DIGEST_LENGTH) {
    if(!setup_dsa_sig(&sigblock, &sigblock_len)) {
      verbose(VERB_QUERY, "verify: failed to setup DSA sig");
      *reason = "use of key for DSA crypto failed";
      EVP_PKEY_free(evp_key);
      return sec_status_bogus;
    }
    docrypto_free = 1;
  }
#endif
#if defined(USE_ECDSA) && defined(USE_DSA)
  else 
#endif
#ifdef USE_ECDSA
  if(algo == LDNS_ECDSAP256SHA256 || algo == LDNS_ECDSAP384SHA384) {
    /* EVP uses ASN prefix on sig, which is not in the wire data */
    if(!setup_ecdsa_sig(&sigblock, &sigblock_len)) {
      verbose(VERB_QUERY, "verify: failed to setup ECDSA sig");
      *reason = "use of signature for ECDSA crypto failed";
      EVP_PKEY_free(evp_key);
      return sec_status_bogus;
    }
    dofree = 1;
  }
#endif /* USE_ECDSA */

  /* do the signature cryptography work */
#ifdef HAVE_EVP_MD_CTX_NEW
  ctx = EVP_MD_CTX_new();
#else
  ctx = (EVP_MD_CTX*)malloc(sizeof(*ctx));
  if(ctx) EVP_MD_CTX_init(ctx);
#endif
  if(!ctx) {
    log_err("EVP_MD_CTX_new: malloc failure");
    EVP_PKEY_free(evp_key);
    if(dofree) free(sigblock);
    else if(docrypto_free) OPENSSL_free(sigblock);
    return sec_status_unchecked;
  }
#ifndef HAVE_EVP_DIGESTVERIFY
  if(EVP_DigestInit(ctx, digest_type) == 0) {
    enum sec_status sec;
    sec = digest_error_status("verify: EVP_DigestInit failed");
    digest_ctx_free(ctx, evp_key, sigblock,
      dofree, docrypto_free);
    return sec;
  }
  if(EVP_DigestUpdate(ctx, (unsigned char*)sldns_buffer_begin(buf), 
    (unsigned int)sldns_buffer_limit(buf)) == 0) {
    log_crypto_verbose(VERB_QUERY, "verify: EVP_DigestUpdate failed",
      ERR_get_error());
    digest_ctx_free(ctx, evp_key, sigblock,
      dofree, docrypto_free);
    return sec_status_unchecked;
  }

  res = EVP_VerifyFinal(ctx, sigblock, sigblock_len, evp_key);
#else /* HAVE_EVP_DIGESTVERIFY */
  if(EVP_DigestVerifyInit(ctx, NULL, digest_type, NULL, evp_key) == 0) {
    enum sec_status sec;
    sec = digest_error_status("verify: EVP_DigestVerifyInit failed");
    digest_ctx_free(ctx, evp_key, sigblock,
      dofree, docrypto_free);
    return sec;
  }
  res = EVP_DigestVerify(ctx, sigblock, sigblock_len,
    (unsigned char*)sldns_buffer_begin(buf),
    sldns_buffer_limit(buf));
#endif
  digest_ctx_free(ctx, evp_key, sigblock,
    dofree, docrypto_free);

  if(res == 1) {
    return sec_status_secure;
  } else if(res == 0) {
    verbose(VERB_QUERY, "verify: signature mismatch");
    *reason = "signature crypto failed";
    return sec_status_bogus;
  }

  log_crypto_error("verify:", ERR_get_error());
  return sec_status_unchecked;
}

/**************************************************/
#elif defined(HAVE_NSS)
/* libnss implementation */
/* nss3 */
#include "sechash.h"
#include "pk11pub.h"
#include "keyhi.h"
#include "secerr.h"
#include "cryptohi.h"
/* nspr4 */
#include "prerror.h"

/* return size of digest if supported, or 0 otherwise */
size_t
nsec3_hash_algo_size_supported(int id)
{
  switch(id) {
  case NSEC3_HASH_SHA1:
    return SHA1_LENGTH;
  default:
    return 0;
  }
}

/* perform nsec3 hash. return false on failure */
int
secalgo_nsec3_hash(int algo, unsigned char* buf, size_t len,
        unsigned char* res)
{
  switch(algo) {
  case NSEC3_HASH_SHA1:
    (void)HASH_HashBuf(HASH_AlgSHA1, res, buf, (unsigned long)len);
    return 1;
  default:
    return 0;
  }
}

void
secalgo_hash_sha256(unsigned char* buf, size_t len, unsigned char* res)
{
  (void)HASH_HashBuf(HASH_AlgSHA256, res, buf, (unsigned long)len);
}

/** the secalgo hash structure */
struct secalgo_hash {
  /** hash context */
  HASHContext* ctx;
};

/** create hash struct of type */
static struct secalgo_hash* secalgo_hash_create_type(HASH_HashType tp)
{
  struct secalgo_hash* h = calloc(1, sizeof(*h));
  if(!h)
    return NULL;
  h->ctx = HASH_Create(tp);
  if(!h->ctx) {
    free(h);
    return NULL;
  }
  return h;
}

struct secalgo_hash* secalgo_hash_create_sha384(void)
{
  return secalgo_hash_create_type(HASH_AlgSHA384);
}

struct secalgo_hash* secalgo_hash_create_sha512(void)
{
  return secalgo_hash_create_type(HASH_AlgSHA512);
}

int secalgo_hash_update(struct secalgo_hash* hash, uint8_t* data, size_t len)
{
  HASH_Update(hash->ctx, (unsigned char*)data, (unsigned int)len);
  return 1;
}

int secalgo_hash_final(struct secalgo_hash* hash, uint8_t* result,
        size_t maxlen, size_t* resultlen)
{
  unsigned int reslen = 0;
  if(HASH_ResultLenContext(hash->ctx) > (unsigned int)maxlen) {
    *resultlen = 0;
    log_err("secalgo_hash_final: hash buffer too small");
    return 0;
  }
  HASH_End(hash->ctx, (unsigned char*)result, &reslen,
    (unsigned int)maxlen);
  *resultlen = (size_t)reslen;
  return 1;
}

void secalgo_hash_delete(struct secalgo_hash* hash)
{
  if(!hash) return;
  HASH_Destroy(hash->ctx);
  free(hash);
}

size_t
ds_digest_size_supported(int algo)
{
  /* uses libNSS */
  switch(algo) {
#ifdef USE_SHA1
    case LDNS_SHA1:
      return SHA1_LENGTH;
#endif
#ifdef USE_SHA2
    case LDNS_SHA256:
      return SHA256_LENGTH;
#endif
#ifdef USE_ECDSA
    case LDNS_SHA384:
      return SHA384_LENGTH;
#endif
    /* GOST not supported in NSS */
    case LDNS_HASH_GOST:
    default: break;
  }
  return 0;
}

int
secalgo_ds_digest(int algo, unsigned char* buf, size_t len,
  unsigned char* res)
{
  /* uses libNSS */
  switch(algo) {
#ifdef USE_SHA1
    case LDNS_SHA1:
      return HASH_HashBuf(HASH_AlgSHA1, res, buf, len)
        == SECSuccess;
#endif
#if defined(USE_SHA2)
    case LDNS_SHA256:
      return HASH_HashBuf(HASH_AlgSHA256, res, buf, len)
        == SECSuccess;
#endif
#ifdef USE_ECDSA
    case LDNS_SHA384:
      return HASH_HashBuf(HASH_AlgSHA384, res, buf, len)
        == SECSuccess;
#endif
    case LDNS_HASH_GOST:
    default: 
      verbose(VERB_QUERY, "unknown DS digest algorithm %d", 
        algo);
      break;
  }
  return 0;
}

int
dnskey_algo_id_is_supported(int id)
{
  /* uses libNSS */
  switch(id) {
  case LDNS_RSAMD5:
    /* RFC 6725 deprecates RSAMD5 */
    return 0;
#if defined(USE_SHA1) || defined(USE_SHA2)
#if defined(USE_DSA) && defined(USE_SHA1)
  case LDNS_DSA:
  case LDNS_DSA_NSEC3:
#endif
#ifdef USE_SHA1
  case LDNS_RSASHA1:
  case LDNS_RSASHA1_NSEC3:
#endif
#ifdef USE_SHA2
  case LDNS_RSASHA256:
#endif
#ifdef USE_SHA2
  case LDNS_RSASHA512:
#endif
    return 1;
#endif /* SHA1 or SHA2 */

#ifdef USE_ECDSA
  case LDNS_ECDSAP256SHA256:
  case LDNS_ECDSAP384SHA384:
    return PK11_TokenExists(CKM_ECDSA);
#endif
  case LDNS_ECC_GOST:
  default:
    return 0;
  }
}

/* return a new public key for NSS */
static SECKEYPublicKey* nss_key_create(KeyType ktype)
{
  SECKEYPublicKey* key;
  PLArenaPool* arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);
  if(!arena) {
    log_err("out of memory, PORT_NewArena failed");
    return NULL;
  }
  key = PORT_ArenaZNew(arena, SECKEYPublicKey);
  if(!key) {
    log_err("out of memory, PORT_ArenaZNew failed");
    PORT_FreeArena(arena, PR_FALSE);
    return NULL;
  }
  key->arena = arena;
  key->keyType = ktype;
  key->pkcs11Slot = NULL;
  key->pkcs11ID = CK_INVALID_HANDLE;
  return key;
}

static SECKEYPublicKey* nss_buf2ecdsa(unsigned char* key, size_t len, int algo)
{
  SECKEYPublicKey* pk;
  SECItem pub = {siBuffer, NULL, 0};
  SECItem params = {siBuffer, NULL, 0};
  static unsigned char param256[] = {
    /* OBJECTIDENTIFIER 1.2.840.10045.3.1.7 (P-256)
     * {iso(1) member-body(2) us(840) ansi-x962(10045) curves(3) prime(1) prime256v1(7)} */
    0x06, 0x08, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07
  };
  static unsigned char param384[] = {
    /* OBJECTIDENTIFIER 1.3.132.0.34 (P-384)
     * {iso(1) identified-organization(3) certicom(132) curve(0) ansip384r1(34)} */
    0x06, 0x05, 0x2b, 0x81, 0x04, 0x00, 0x22
  };
  unsigned char buf[256+2]; /* sufficient for 2*384/8+1 */

  /* check length, which uncompressed must be 2 bignums */
  if(algo == LDNS_ECDSAP256SHA256) {
    if(len != 2*256/8) return NULL;
    /* ECCurve_X9_62_PRIME_256V1 */
  } else if(algo == LDNS_ECDSAP384SHA384) {
    if(len != 2*384/8) return NULL;
    /* ECCurve_X9_62_PRIME_384R1 */
  } else    return NULL;

  buf[0] = 0x04; /* POINT_FORM_UNCOMPRESSED */
  memmove(buf+1, key, len);
  pub.data = buf;
  pub.len = len+1;
  if(algo == LDNS_ECDSAP256SHA256) {
    params.data = param256;
    params.len = sizeof(param256);
  } else {
    params.data = param384;
    params.len = sizeof(param384);
  }

  pk = nss_key_create(ecKey);
  if(!pk)
    return NULL;
  pk->u.ec.size = (len/2)*8;
  if(SECITEM_CopyItem(pk->arena, &pk->u.ec.publicValue, &pub)) {
    SECKEY_DestroyPublicKey(pk);
    return NULL;
  }
  if(SECITEM_CopyItem(pk->arena, &pk->u.ec.DEREncodedParams, &params)) {
    SECKEY_DestroyPublicKey(pk);
    return NULL;
  }

  return pk;
}

#if defined(USE_DSA) && defined(USE_SHA1)
static SECKEYPublicKey* nss_buf2dsa(unsigned char* key, size_t len)
{
  SECKEYPublicKey* pk;
  uint8_t T;
  uint16_t length;
  uint16_t offset;
  SECItem Q = {siBuffer, NULL, 0};
  SECItem P = {siBuffer, NULL, 0};
  SECItem G = {siBuffer, NULL, 0};
  SECItem Y = {siBuffer, NULL, 0};

  if(len == 0)
    return NULL;
  T = (uint8_t)key[0];
  length = (64 + T * 8);
  offset = 1;

  if (T > 8) {
    return NULL;
  }
  if(len < (size_t)1 + SHA1_LENGTH + 3*length)
    return NULL;

  Q.data = key+offset;
  Q.len = SHA1_LENGTH;
  offset += SHA1_LENGTH;

  P.data = key+offset;
  P.len = length;
  offset += length;

  G.data = key+offset;
  G.len = length;
  offset += length;

  Y.data = key+offset;
  Y.len = length;
  offset += length;

  pk = nss_key_create(dsaKey);
  if(!pk)
    return NULL;
  if(SECITEM_CopyItem(pk->arena, &pk->u.dsa.params.prime, &P)) {
    SECKEY_DestroyPublicKey(pk);
    return NULL;
  }
  if(SECITEM_CopyItem(pk->arena, &pk->u.dsa.params.subPrime, &Q)) {
    SECKEY_DestroyPublicKey(pk);
    return NULL;
  }
  if(SECITEM_CopyItem(pk->arena, &pk->u.dsa.params.base, &G)) {
    SECKEY_DestroyPublicKey(pk);
    return NULL;
  }
  if(SECITEM_CopyItem(pk->arena, &pk->u.dsa.publicValue, &Y)) {
    SECKEY_DestroyPublicKey(pk);
    return NULL;
  }
  return pk;
}
#endif /* USE_DSA && USE_SHA1 */

static SECKEYPublicKey* nss_buf2rsa(unsigned char* key, size_t len)
{
  SECKEYPublicKey* pk;
  uint16_t exp;
  uint16_t offset;
  uint16_t int16;
  SECItem modulus = {siBuffer, NULL, 0};
  SECItem exponent = {siBuffer, NULL, 0};
  if(len == 0)
    return NULL;
  if(key[0] == 0) {
    if(len < 3)
      return NULL;
    /* the exponent is too large so it's places further */
    memmove(&int16, key+1, 2);
    exp = ntohs(int16);
    offset = 3;
  } else {
    exp = key[0];
    offset = 1;
  }

  /* key length at least one */
  if(len < (size_t)offset + exp + 1)
    return NULL;
  
  exponent.data = key+offset;
  exponent.len = exp;
  offset += exp;
  modulus.data = key+offset;
  modulus.len = (len - offset);

  pk = nss_key_create(rsaKey);
  if(!pk)
    return NULL;
  if(SECITEM_CopyItem(pk->arena, &pk->u.rsa.modulus, &modulus)) {
    SECKEY_DestroyPublicKey(pk);
    return NULL;
  }
  if(SECITEM_CopyItem(pk->arena, &pk->u.rsa.publicExponent, &exponent)) {
    SECKEY_DestroyPublicKey(pk);
    return NULL;
  }
  return pk;
}

/**
 * Setup key and digest for verification. Adjust sig if necessary.
 *
 * @param algo: key algorithm
 * @param evp_key: EVP PKEY public key to create.
 * @param digest_type: digest type to use
 * @param key: key to setup for.
 * @param keylen: length of key.
 * @param prefix: if returned, the ASN prefix for the hashblob.
 * @param prefixlen: length of the prefix.
 * @return false on failure.
 */
static int
nss_setup_key_digest(int algo, SECKEYPublicKey** pubkey, HASH_HashType* htype,
  unsigned char* key, size_t keylen, unsigned char** prefix,
  size_t* prefixlen)
{
  /* uses libNSS */

  /* hash prefix for md5, RFC2537 */
  static unsigned char p_md5[] = {0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, 0x2a,
  0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, 0x05, 0x00, 0x04, 0x10};
  /* hash prefix to prepend to hash output, from RFC3110 */
  static unsigned char p_sha1[] = {0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2B,
    0x0E, 0x03, 0x02, 0x1A, 0x05, 0x00, 0x04, 0x14};
  /* from RFC5702 */
  static unsigned char p_sha256[] = {0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60,
  0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20};
  static unsigned char p_sha512[] = {0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60,
  0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40};
  /* from RFC6234 */
  /* for future RSASHA384 .. 
  static unsigned char p_sha384[] = {0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60,
  0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30};
  */

  switch(algo) {

#if defined(USE_SHA1) || defined(USE_SHA2)
#if defined(USE_DSA) && defined(USE_SHA1)
    case LDNS_DSA:
    case LDNS_DSA_NSEC3:
      *pubkey = nss_buf2dsa(key, keylen);
      if(!*pubkey) {
        log_err("verify: malloc failure in crypto");
        return 0;
      }
      *htype = HASH_AlgSHA1;
      /* no prefix for DSA verification */
      break;
#endif
#ifdef USE_SHA1
    case LDNS_RSASHA1:
    case LDNS_RSASHA1_NSEC3:
#endif
#ifdef USE_SHA2
    case LDNS_RSASHA256:
#endif
#ifdef USE_SHA2
    case LDNS_RSASHA512:
#endif
      *pubkey = nss_buf2rsa(key, keylen);
      if(!*pubkey) {
        log_err("verify: malloc failure in crypto");
        return 0;
      }
      /* select SHA version */
#ifdef USE_SHA2
      if(algo == LDNS_RSASHA256) {
        *htype = HASH_AlgSHA256;
        *prefix = p_sha256;
        *prefixlen = sizeof(p_sha256);
      } else
#endif
#ifdef USE_SHA2
        if(algo == LDNS_RSASHA512) {
        *htype = HASH_AlgSHA512;
        *prefix = p_sha512;
        *prefixlen = sizeof(p_sha512);
      } else
#endif
#ifdef USE_SHA1
      {
        *htype = HASH_AlgSHA1;
        *prefix = p_sha1;
        *prefixlen = sizeof(p_sha1);
      }
#else
      {
        verbose(VERB_QUERY, "verify: no digest algo");
        return 0;
      }
#endif

      break;
#endif /* SHA1 or SHA2 */

    case LDNS_RSAMD5:
      *pubkey = nss_buf2rsa(key, keylen);
      if(!*pubkey) {
        log_err("verify: malloc failure in crypto");
        return 0;
      }
      *htype = HASH_AlgMD5;
      *prefix = p_md5;
      *prefixlen = sizeof(p_md5);

      break;
#ifdef USE_ECDSA
    case LDNS_ECDSAP256SHA256:
      *pubkey = nss_buf2ecdsa(key, keylen,
        LDNS_ECDSAP256SHA256);
      if(!*pubkey) {
        log_err("verify: malloc failure in crypto");
        return 0;
      }
      *htype = HASH_AlgSHA256;
      /* no prefix for DSA verification */
      break;
    case LDNS_ECDSAP384SHA384:
      *pubkey = nss_buf2ecdsa(key, keylen,
        LDNS_ECDSAP384SHA384);
      if(!*pubkey) {
        log_err("verify: malloc failure in crypto");
        return 0;
      }
      *htype = HASH_AlgSHA384;
      /* no prefix for DSA verification */
      break;
#endif /* USE_ECDSA */
    case LDNS_ECC_GOST:
    default:
      verbose(VERB_QUERY, "verify: unknown algorithm %d", 
        algo);
      return 0;
  }
  return 1;
}

/**
 * Check a canonical sig+rrset and signature against a dnskey
 * @param buf: buffer with data to verify, the first rrsig part and the
 *  canonicalized rrset.
 * @param algo: DNSKEY algorithm.
 * @param sigblock: signature rdata field from RRSIG
 * @param sigblock_len: length of sigblock data.
 * @param key: public key data from DNSKEY RR.
 * @param keylen: length of keydata.
 * @param reason: bogus reason in more detail.
 * @return secure if verification succeeded, bogus on crypto failure,
 *  unchecked on format errors and alloc failures.
 */
enum sec_status
verify_canonrrset(sldns_buffer* buf, int algo, unsigned char* sigblock, 
  unsigned int sigblock_len, unsigned char* key, unsigned int keylen,
  char** reason)
{
  /* uses libNSS */
  /* large enough for the different hashes */
  unsigned char hash[HASH_LENGTH_MAX];
  unsigned char hash2[HASH_LENGTH_MAX*2];
  HASH_HashType htype = 0;
  SECKEYPublicKey* pubkey = NULL;
  SECItem secsig = {siBuffer, sigblock, sigblock_len};
  SECItem sechash = {siBuffer, hash, 0};
  SECStatus res;
  unsigned char* prefix = NULL; /* prefix for hash, RFC3110, RFC5702 */
  size_t prefixlen = 0;
  int err;

  if(!nss_setup_key_digest(algo, &pubkey, &htype, key, keylen,
    &prefix, &prefixlen)) {
    verbose(VERB_QUERY, "verify: failed to setup key");
    *reason = "use of key for crypto failed";
    SECKEY_DestroyPublicKey(pubkey);
    return sec_status_bogus;
  }

#if defined(USE_DSA) && defined(USE_SHA1)
  /* need to convert DSA, ECDSA signatures? */
  if((algo == LDNS_DSA || algo == LDNS_DSA_NSEC3)) {
    if(sigblock_len == 1+2*SHA1_LENGTH) {
      secsig.data ++;
      secsig.len --;
    } else {
      SECItem* p = DSAU_DecodeDerSig(&secsig);
      if(!p) {
        verbose(VERB_QUERY, "verify: failed DER decode");
        *reason = "signature DER decode failed";
        SECKEY_DestroyPublicKey(pubkey);
        return sec_status_bogus;
      }
      if(SECITEM_CopyItem(pubkey->arena, &secsig, p)) {
        log_err("alloc failure in DER decode");
        SECKEY_DestroyPublicKey(pubkey);
        SECITEM_FreeItem(p, PR_TRUE);
        return sec_status_unchecked;
      }
      SECITEM_FreeItem(p, PR_TRUE);
    }
  }
#endif /* USE_DSA */

  /* do the signature cryptography work */
  /* hash the data */
  sechash.len = HASH_ResultLen(htype);
  if(sechash.len > sizeof(hash)) {
    verbose(VERB_QUERY, "verify: hash too large for buffer");
    SECKEY_DestroyPublicKey(pubkey);
    return sec_status_unchecked;
  }
  if(HASH_HashBuf(htype, hash, (unsigned char*)sldns_buffer_begin(buf),
    (unsigned int)sldns_buffer_limit(buf)) != SECSuccess) {
    verbose(VERB_QUERY, "verify: HASH_HashBuf failed");
    SECKEY_DestroyPublicKey(pubkey);
    return sec_status_unchecked;
  }
  if(prefix) {
    int hashlen = sechash.len;
    if(prefixlen+hashlen > sizeof(hash2)) {
      verbose(VERB_QUERY, "verify: hashprefix too large");
      SECKEY_DestroyPublicKey(pubkey);
      return sec_status_unchecked;
    }
    sechash.data = hash2;
    sechash.len = prefixlen+hashlen;
    memcpy(sechash.data, prefix, prefixlen);
    memmove(sechash.data+prefixlen, hash, hashlen);
  }

  /* verify the signature */
  res = PK11_Verify(pubkey, &secsig, &sechash, NULL /*wincx*/);
  SECKEY_DestroyPublicKey(pubkey);

  if(res == SECSuccess) {
    return sec_status_secure;
  }
  err = PORT_GetError();
  if(err != SEC_ERROR_BAD_SIGNATURE) {
    /* failed to verify */
    verbose(VERB_QUERY, "verify: PK11_Verify failed: %s",
      PORT_ErrorToString(err));
    /* if it is not supported, like ECC is removed, we get,
     * SEC_ERROR_NO_MODULE */
    if(err == SEC_ERROR_NO_MODULE)
      return sec_status_unchecked;
    /* but other errors are commonly returned
     * for a bad signature from NSS.  Thus we return bogus,
     * not unchecked */
    *reason = "signature crypto failed";
    return sec_status_bogus;
  }
  verbose(VERB_QUERY, "verify: signature mismatch: %s",
    PORT_ErrorToString(err));
  *reason = "signature crypto failed";
  return sec_status_bogus;
}

#elif defined(HAVE_NETTLE)

#include "sha.h"
#include "bignum.h"
#include "macros.h"
#include "rsa.h"
#include "dsa.h"
#ifdef HAVE_NETTLE_DSA_COMPAT_H
#include "dsa-compat.h"
#endif
#include "asn1.h"
#ifdef USE_ECDSA
#include "ecdsa.h"
#include "ecc-curve.h"
#endif
#ifdef HAVE_NETTLE_EDDSA_H
#include "eddsa.h"
#endif

static int
_digest_nettle(int algo, uint8_t* buf, size_t len,
  unsigned char* res)
{
  switch(algo) {
    case SHA1_DIGEST_SIZE:
    {
      struct sha1_ctx ctx;
      sha1_init(&ctx);
      sha1_update(&ctx, len, buf);
      sha1_digest(&ctx, SHA1_DIGEST_SIZE, res);
      return 1;
    }
    case SHA256_DIGEST_SIZE:
    {
      struct sha256_ctx ctx;
      sha256_init(&ctx);
      sha256_update(&ctx, len, buf);
      sha256_digest(&ctx, SHA256_DIGEST_SIZE, res);
      return 1;
    }
    case SHA384_DIGEST_SIZE:
    {
      struct sha384_ctx ctx;
      sha384_init(&ctx);
      sha384_update(&ctx, len, buf);
      sha384_digest(&ctx, SHA384_DIGEST_SIZE, res);
      return 1;
    }
    case SHA512_DIGEST_SIZE:
    {
      struct sha512_ctx ctx;
      sha512_init(&ctx);
      sha512_update(&ctx, len, buf);
      sha512_digest(&ctx, SHA512_DIGEST_SIZE, res);
      return 1;
    }
    default:
      break;
  }
  return 0;
}

/* return size of digest if supported, or 0 otherwise */
size_t
nsec3_hash_algo_size_supported(int id)
{
  switch(id) {
  case NSEC3_HASH_SHA1:
    return SHA1_DIGEST_SIZE;
  default:
    return 0;
  }
}

/* perform nsec3 hash. return false on failure */
int
secalgo_nsec3_hash(int algo, unsigned char* buf, size_t len,
        unsigned char* res)
{
  switch(algo) {
  case NSEC3_HASH_SHA1:
    return _digest_nettle(SHA1_DIGEST_SIZE, (uint8_t*)buf, len,
      res);
  default:
    return 0;
  }
}

void
secalgo_hash_sha256(unsigned char* buf, size_t len, unsigned char* res)
{
  _digest_nettle(SHA256_DIGEST_SIZE, (uint8_t*)buf, len, res);
}

/** secalgo hash structure */
struct secalgo_hash {
  /** if it is 384 or 512 */
  int active;
  /** context for sha384 */
  struct sha384_ctx ctx384;
  /** context for sha512 */
  struct sha512_ctx ctx512;
};

struct secalgo_hash* secalgo_hash_create_sha384(void)
{
  struct secalgo_hash* h = calloc(1, sizeof(*h));
  if(!h)
    return NULL;
  h->active = 384;
  sha384_init(&h->ctx384);
  return h;
}

struct secalgo_hash* secalgo_hash_create_sha512(void)
{
  struct secalgo_hash* h = calloc(1, sizeof(*h));
  if(!h)
    return NULL;
  h->active = 512;
  sha512_init(&h->ctx512);
  return h;
}

int secalgo_hash_update(struct secalgo_hash* hash, uint8_t* data, size_t len)
{
  if(hash->active == 384) {
    sha384_update(&hash->ctx384, len, data);
  } else if(hash->active == 512) {
    sha512_update(&hash->ctx512, len, data);
  } else {
    return 0;
  }
  return 1;
}

int secalgo_hash_final(struct secalgo_hash* hash, uint8_t* result,
        size_t maxlen, size_t* resultlen)
{
  if(hash->active == 384) {
    if(SHA384_DIGEST_SIZE > maxlen) {
      *resultlen = 0;
      log_err("secalgo_hash_final: hash buffer too small");
      return 0;
    }
    *resultlen = SHA384_DIGEST_SIZE;
    sha384_digest(&hash->ctx384, SHA384_DIGEST_SIZE,
      (unsigned char*)result);
  } else if(hash->active == 512) {
    if(SHA512_DIGEST_SIZE > maxlen) {
      *resultlen = 0;
      log_err("secalgo_hash_final: hash buffer too small");
      return 0;
    }
    *resultlen = SHA512_DIGEST_SIZE;
    sha512_digest(&hash->ctx512, SHA512_DIGEST_SIZE,
      (unsigned char*)result);
  } else {
    *resultlen = 0;
    return 0;
  }
  return 1;
}

void secalgo_hash_delete(struct secalgo_hash* hash)
{
  if(!hash) return;
  free(hash);
}

/**
 * Return size of DS digest according to its hash algorithm.
 * @param algo: DS digest algo.
 * @return size in bytes of digest, or 0 if not supported.
 */
size_t
ds_digest_size_supported(int algo)
{
  switch(algo) {
    case LDNS_SHA1:
#ifdef USE_SHA1
      return SHA1_DIGEST_SIZE;
#else
      if(fake_sha1) return 20;
      return 0;
#endif
#ifdef USE_SHA2
    case LDNS_SHA256:
      return SHA256_DIGEST_SIZE;
#endif
#ifdef USE_ECDSA
    case LDNS_SHA384:
      return SHA384_DIGEST_SIZE;
#endif
    /* GOST not supported */
    case LDNS_HASH_GOST:
    default:
      break;
  }
  return 0;
}

int
secalgo_ds_digest(int algo, unsigned char* buf, size_t len,
  unsigned char* res)
{
  switch(algo) {
#ifdef USE_SHA1
    case LDNS_SHA1:
      return _digest_nettle(SHA1_DIGEST_SIZE, buf, len, res);
#endif
#if defined(USE_SHA2)
    case LDNS_SHA256:
      return _digest_nettle(SHA256_DIGEST_SIZE, buf, len, res);
#endif
#ifdef USE_ECDSA
    case LDNS_SHA384:
      return _digest_nettle(SHA384_DIGEST_SIZE, buf, len, res);

#endif
    case LDNS_HASH_GOST:
    default:
      verbose(VERB_QUERY, "unknown DS digest algorithm %d",
        algo);
      break;
  }
  return 0;
}

int
dnskey_algo_id_is_supported(int id)
{
  /* uses libnettle */
  switch(id) {
  case LDNS_DSA:
  case LDNS_DSA_NSEC3:
#if defined(USE_DSA) && defined(USE_SHA1)
    return 1;
#else
    if(fake_dsa || fake_sha1) return 1;
    return 0;
#endif
  case LDNS_RSASHA1:
  case LDNS_RSASHA1_NSEC3:
#ifdef USE_SHA1
    return 1;
#else
    if(fake_sha1) return 1;
    return 0;
#endif
#ifdef USE_SHA2
  case LDNS_RSASHA256:
  case LDNS_RSASHA512:
#endif
#ifdef USE_ECDSA
  case LDNS_ECDSAP256SHA256:
  case LDNS_ECDSAP384SHA384:
#endif
    return 1;
#ifdef USE_ED25519
  case LDNS_ED25519:
    return 1;
#endif
  case LDNS_RSAMD5: /* RFC 6725 deprecates RSAMD5 */
  case LDNS_ECC_GOST:
  default:
    return 0;
  }
}

#if defined(USE_DSA) && defined(USE_SHA1)
static char *
_verify_nettle_dsa(sldns_buffer* buf, unsigned char* sigblock,
  unsigned int sigblock_len, unsigned char* key, unsigned int keylen)
{
  uint8_t digest[SHA1_DIGEST_SIZE];
  uint8_t key_t_value;
  int res = 0;
  size_t offset;
  struct dsa_public_key pubkey;
  struct dsa_signature signature;
  unsigned int expected_len;

  /* Extract DSA signature from the record */
  nettle_dsa_signature_init(&signature);
  /* Signature length: 41 bytes - RFC 2536 sec. 3 */
  if(sigblock_len == 41) {
    if(key[0] != sigblock[0])
      return "invalid T value in DSA signature or pubkey";
    nettle_mpz_set_str_256_u(signature.r, 20, sigblock+1);
    nettle_mpz_set_str_256_u(signature.s, 20, sigblock+1+20);
  } else {
    /* DER encoded, decode the ASN1 notated R and S bignums */
    /* SEQUENCE { r INTEGER, s INTEGER } */
    struct asn1_der_iterator i, seq;
    if(asn1_der_iterator_first(&i, sigblock_len,
      (uint8_t*)sigblock) != ASN1_ITERATOR_CONSTRUCTED
      || i.type != ASN1_SEQUENCE)
      return "malformed DER encoded DSA signature";
    /* decode this element of i using the seq iterator */
    if(asn1_der_decode_constructed(&i, &seq) !=
      ASN1_ITERATOR_PRIMITIVE || seq.type != ASN1_INTEGER)
      return "malformed DER encoded DSA signature";
    if(!asn1_der_get_bignum(&seq, signature.r, 20*8))
      return "malformed DER encoded DSA signature";
    if(asn1_der_iterator_next(&seq) != ASN1_ITERATOR_PRIMITIVE
      || seq.type != ASN1_INTEGER)
      return "malformed DER encoded DSA signature";
    if(!asn1_der_get_bignum(&seq, signature.s, 20*8))
      return "malformed DER encoded DSA signature";
    if(asn1_der_iterator_next(&i) != ASN1_ITERATOR_END)
      return "malformed DER encoded DSA signature";
  }

  /* Validate T values constraints - RFC 2536 sec. 2 & sec. 3 */
  key_t_value = key[0];
  if (key_t_value > 8) {
    return "invalid T value in DSA pubkey";
  }

  /* Pubkey minimum length: 21 bytes - RFC 2536 sec. 2 */
  if (keylen < 21) {
    return "DSA pubkey too short";
  }

  expected_len =   1 +    /* T */
            20 +    /* Q */
           (64 + key_t_value*8) + /* P */
           (64 + key_t_value*8) + /* G */
           (64 + key_t_value*8);  /* Y */
  if (keylen != expected_len ) {
    return "invalid DSA pubkey length";
  }

  /* Extract DSA pubkey from the record */
  nettle_dsa_public_key_init(&pubkey);
  offset = 1;
  nettle_mpz_set_str_256_u(pubkey.q, 20, key+offset);
  offset += 20;
  nettle_mpz_set_str_256_u(pubkey.p, (64 + key_t_value*8), key+offset);
  offset += (64 + key_t_value*8);
  nettle_mpz_set_str_256_u(pubkey.g, (64 + key_t_value*8), key+offset);
  offset += (64 + key_t_value*8);
  nettle_mpz_set_str_256_u(pubkey.y, (64 + key_t_value*8), key+offset);

  /* Digest content of "buf" and verify its DSA signature in "sigblock"*/
  res = _digest_nettle(SHA1_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
            (unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
  res &= dsa_sha1_verify_digest(&pubkey, digest, &signature);

  /* Clear and return */
  nettle_dsa_signature_clear(&signature);
  nettle_dsa_public_key_clear(&pubkey);
  if (!res)
    return "DSA signature verification failed";
  else
    return NULL;
}
#endif /* USE_DSA */

static char *
_verify_nettle_rsa(sldns_buffer* buf, unsigned int digest_size, char* sigblock,
  unsigned int sigblock_len, uint8_t* key, unsigned int keylen)
{
  uint16_t exp_len = 0;
  size_t exp_offset = 0, mod_offset = 0;
  struct rsa_public_key pubkey;
  mpz_t signature;
  int res = 0;

  /* RSA pubkey parsing as per RFC 3110 sec. 2 */
  if( keylen <= 1) {
    return "null RSA key";
  }
  if (key[0] != 0) {
    /* 1-byte length */
    exp_len = key[0];
    exp_offset = 1;
  } else {
    /* 1-byte NUL + 2-bytes exponent length */
    if (keylen < 3) {
      return "incorrect RSA key length";
    }
    exp_len = READ_UINT16(key+1);
    if (exp_len == 0)
      return "null RSA exponent length";
    exp_offset = 3;
  }
  /* Check that we are not over-running input length */
  if (keylen < exp_offset + exp_len + 1) {
    return "RSA key content shorter than expected";
  }
  mod_offset = exp_offset + exp_len;
  nettle_rsa_public_key_init(&pubkey);
  pubkey.size = keylen - mod_offset;
  nettle_mpz_set_str_256_u(pubkey.e, exp_len, &key[exp_offset]);
  nettle_mpz_set_str_256_u(pubkey.n, pubkey.size, &key[mod_offset]);

  /* Digest content of "buf" and verify its RSA signature in "sigblock"*/
  nettle_mpz_init_set_str_256_u(signature, sigblock_len, (uint8_t*)sigblock);
  switch (digest_size) {
    case SHA1_DIGEST_SIZE:
    {
      uint8_t digest[SHA1_DIGEST_SIZE];
      res = _digest_nettle(SHA1_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
            (unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
      res &= rsa_sha1_verify_digest(&pubkey, digest, signature);
      break;
    }
    case SHA256_DIGEST_SIZE:
    {
      uint8_t digest[SHA256_DIGEST_SIZE];
      res = _digest_nettle(SHA256_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
            (unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
      res &= rsa_sha256_verify_digest(&pubkey, digest, signature);
      break;
    }
    case SHA512_DIGEST_SIZE:
    {
      uint8_t digest[SHA512_DIGEST_SIZE];
      res = _digest_nettle(SHA512_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
            (unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
      res &= rsa_sha512_verify_digest(&pubkey, digest, signature);
      break;
    }
    default:
      break;
  }

  /* Clear and return */
  nettle_rsa_public_key_clear(&pubkey);
  mpz_clear(signature);
  if (!res) {
    return "RSA signature verification failed";
  } else {
    return NULL;
  }
}

#ifdef USE_ECDSA
static char *
_verify_nettle_ecdsa(sldns_buffer* buf, unsigned int digest_size, unsigned char* sigblock,
  unsigned int sigblock_len, unsigned char* key, unsigned int keylen)
{
  int res = 0;
  struct ecc_point pubkey;
  struct dsa_signature signature;

  /* Always matched strength, as per RFC 6605 sec. 1 */
  if (sigblock_len != 2*digest_size || keylen != 2*digest_size) {
    return "wrong ECDSA signature length";
  }

  /* Parse ECDSA signature as per RFC 6605 sec. 4 */
  nettle_dsa_signature_init(&signature);
  switch (digest_size) {
    case SHA256_DIGEST_SIZE:
    {
      uint8_t digest[SHA256_DIGEST_SIZE];
      mpz_t x, y;
      nettle_ecc_point_init(&pubkey, nettle_get_secp_256r1());
      nettle_mpz_init_set_str_256_u(x, SHA256_DIGEST_SIZE, key);
      nettle_mpz_init_set_str_256_u(y, SHA256_DIGEST_SIZE, key+SHA256_DIGEST_SIZE);
      nettle_mpz_set_str_256_u(signature.r, SHA256_DIGEST_SIZE, sigblock);
      nettle_mpz_set_str_256_u(signature.s, SHA256_DIGEST_SIZE, sigblock+SHA256_DIGEST_SIZE);
      res = _digest_nettle(SHA256_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
            (unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
      res &= nettle_ecc_point_set(&pubkey, x, y);
      res &= nettle_ecdsa_verify (&pubkey, SHA256_DIGEST_SIZE, digest, &signature);
      mpz_clear(x);
      mpz_clear(y);
      nettle_ecc_point_clear(&pubkey);
      break;
    }
    case SHA384_DIGEST_SIZE:
    {
      uint8_t digest[SHA384_DIGEST_SIZE];
      mpz_t x, y;
      nettle_ecc_point_init(&pubkey, nettle_get_secp_384r1());
      nettle_mpz_init_set_str_256_u(x, SHA384_DIGEST_SIZE, key);
      nettle_mpz_init_set_str_256_u(y, SHA384_DIGEST_SIZE, key+SHA384_DIGEST_SIZE);
      nettle_mpz_set_str_256_u(signature.r, SHA384_DIGEST_SIZE, sigblock);
      nettle_mpz_set_str_256_u(signature.s, SHA384_DIGEST_SIZE, sigblock+SHA384_DIGEST_SIZE);
      res = _digest_nettle(SHA384_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
            (unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
      res &= nettle_ecc_point_set(&pubkey, x, y);
      res &= nettle_ecdsa_verify (&pubkey, SHA384_DIGEST_SIZE, digest, &signature);
      mpz_clear(x);
      mpz_clear(y);
      nettle_ecc_point_clear(&pubkey);
      break;
    }
    default:
      return "unknown ECDSA algorithm";
  }

  /* Clear and return */
  nettle_dsa_signature_clear(&signature);
  if (!res)
    return "ECDSA signature verification failed";
  else
    return NULL;
}
#endif

#ifdef USE_ED25519
static char *
_verify_nettle_ed25519(sldns_buffer* buf, unsigned char* sigblock,
  unsigned int sigblock_len, unsigned char* key, unsigned int keylen)
{
  int res = 0;

  if(sigblock_len != ED25519_SIGNATURE_SIZE) {
    return "wrong ED25519 signature length";
  }
  if(keylen != ED25519_KEY_SIZE) {
    return "wrong ED25519 key length";
  }

  res = ed25519_sha512_verify((uint8_t*)key, sldns_buffer_limit(buf),
    sldns_buffer_begin(buf), (uint8_t*)sigblock);

  if (!res)
    return "ED25519 signature verification failed";
  else
    return NULL;
}
#endif

/**
 * Check a canonical sig+rrset and signature against a dnskey
 * @param buf: buffer with data to verify, the first rrsig part and the
 *  canonicalized rrset.
 * @param algo: DNSKEY algorithm.
 * @param sigblock: signature rdata field from RRSIG
 * @param sigblock_len: length of sigblock data.
 * @param key: public key data from DNSKEY RR.
 * @param keylen: length of keydata.
 * @param reason: bogus reason in more detail.
 * @return secure if verification succeeded, bogus on crypto failure,
 *  unchecked on format errors and alloc failures.
 */
enum sec_status
verify_canonrrset(sldns_buffer* buf, int algo, unsigned char* sigblock,
  unsigned int sigblock_len, unsigned char* key, unsigned int keylen,
  char** reason)
{
  unsigned int digest_size = 0;

  if (sigblock_len == 0 || keylen == 0) {
    *reason = "null signature";
    return sec_status_bogus;
  }

#ifndef USE_DSA
  if((algo == LDNS_DSA || algo == LDNS_DSA_NSEC3) &&(fake_dsa||fake_sha1))
    return sec_status_secure;
#endif
#ifndef USE_SHA1
  if(fake_sha1 && (algo == LDNS_DSA || algo == LDNS_DSA_NSEC3 || algo == LDNS_RSASHA1 || algo == LDNS_RSASHA1_NSEC3))
    return sec_status_secure;
#endif

  switch(algo) {
#if defined(USE_DSA) && defined(USE_SHA1)
  case LDNS_DSA:
  case LDNS_DSA_NSEC3:
    *reason = _verify_nettle_dsa(buf, sigblock, sigblock_len, key, keylen);
    if (*reason != NULL)
      return sec_status_bogus;
    else
      return sec_status_secure;
#endif /* USE_DSA */

#ifdef USE_SHA1
  case LDNS_RSASHA1:
  case LDNS_RSASHA1_NSEC3:
    digest_size = (digest_size ? digest_size : SHA1_DIGEST_SIZE);
#endif
    /* double fallthrough annotation to please gcc parser */
    ATTR_FALLTHROUGH
    /* fallthrough */
#ifdef USE_SHA2
    /* fallthrough */
  case LDNS_RSASHA256:
    digest_size = (digest_size ? digest_size : SHA256_DIGEST_SIZE);
    ATTR_FALLTHROUGH
    /* fallthrough */
  case LDNS_RSASHA512:
    digest_size = (digest_size ? digest_size : SHA512_DIGEST_SIZE);

#endif
    *reason = _verify_nettle_rsa(buf, digest_size, (char*)sigblock,
            sigblock_len, key, keylen);
    if (*reason != NULL)
      return sec_status_bogus;
    else
      return sec_status_secure;

#ifdef USE_ECDSA
  case LDNS_ECDSAP256SHA256:
    digest_size = (digest_size ? digest_size : SHA256_DIGEST_SIZE);
    ATTR_FALLTHROUGH
    /* fallthrough */
  case LDNS_ECDSAP384SHA384:
    digest_size = (digest_size ? digest_size : SHA384_DIGEST_SIZE);
    *reason = _verify_nettle_ecdsa(buf, digest_size, sigblock,
            sigblock_len, key, keylen);
    if (*reason != NULL)
      return sec_status_bogus;
    else
      return sec_status_secure;
#endif
#ifdef USE_ED25519
  case LDNS_ED25519:
    *reason = _verify_nettle_ed25519(buf, sigblock, sigblock_len,
      key, keylen);
    if (*reason != NULL)
      return sec_status_bogus;
    else
      return sec_status_secure;
#endif
  case LDNS_RSAMD5:
  case LDNS_ECC_GOST:
  default:
    *reason = "unable to verify signature, unknown algorithm";
    return sec_status_bogus;
  }
}

#endif /* HAVE_SSL or HAVE_NSS or HAVE_NETTLE */

Coverage Report

Created: 2025-11-24 06:14