text: /* LibTomCrypt, modular cryptographic library -- Tom St Denis
   *
   * LibTomCrypt is a library that provides various cryptographic
   * algorithms in a highly modular and flexible manner.
   *
   * The library is free for all purposes without any express
   * guarantee it works.
   */
  #include "tomcrypt.h"
  
  /**
    @file rsa_import.c
    Import an RSA key from a X.509 certificate, Steffen Jaeckel
  */
  
  #ifdef LTC_MRSA
  
  /**
    Import an RSA key from a X.509 certificate
    @param in      The packet to import from
    @param inlen   It's length (octets)
    @param key     [out] Destination for newly imported key
    @return CRYPT_OK if successful, upon error allocated memory is freed
  */
  int rsa_import_x509(const unsigned char *in, unsigned long inlen, rsa_key *key)
  {
     int           err;
     unsigned char *tmpbuf;
     unsigned long tmpbuf_len, tmp_inlen;
     ltc_asn1_list *decoded_list = NULL, *l;
  
     LTC_ARGCHK(in          != NULL);
     LTC_ARGCHK(key         != NULL);
     LTC_ARGCHK(ltc_mp.name != NULL);
  
     /* init key */
     if ((err = mp_init_multi(&key->e, &key->d, &key->N, &key->dQ,
                              &key->dP, &key->qP, &key->p, &key->q, NULL)) != CRYPT_OK) {
        return err;
     }
  
     tmpbuf_len = inlen;
     tmpbuf = XCALLOC(1, tmpbuf_len);
     if (tmpbuf == NULL) {
         err = CRYPT_MEM;
         goto LBL_ERR;
     }
  
     tmp_inlen = inlen;
     if ((err = der_decode_sequence_flexi(in, &tmp_inlen, &decoded_list)) == CRYPT_OK) {
        l = decoded_list;
        /* Move 2 levels up in the tree
           SEQUENCE
               SEQUENCE
                   ...
         */
        if (l->type == LTC_ASN1_SEQUENCE && l->child) {
           l = l->child;
           if (l->type == LTC_ASN1_SEQUENCE && l->child) {
              l = l->child;
  
              err = CRYPT_ERROR;
  
              /* Move forward in the tree until we find this combination
                   ...
                   SEQUENCE
                       SEQUENCE
                           OBJECT IDENTIFIER 1.2.840.113549.1.1.1
                           NULL
                       BIT STRING
               */
              do {
                 /* The additional check for l->data is there to make sure
                  * we won't try to decode a list that has been 'shrunk'
                  */
                 if (l->type == LTC_ASN1_SEQUENCE && l->data && l->child &&
                       l->child->type == LTC_ASN1_SEQUENCE && l->child->child &&
                       l->child->child->type == LTC_ASN1_OBJECT_IDENTIFIER && l->child->next &&
                       l->child->next->type == LTC_ASN1_BIT_STRING) {
                    err = der_decode_subject_public_key_info(l->data, l->size,
                         PKA_RSA, tmpbuf, &tmpbuf_len,
                         LTC_ASN1_NULL, NULL, 0);
                    if (err == CRYPT_OK) {
                       /* now it should be SEQUENCE { INTEGER, INTEGER } */
                       if ((err = der_decode_sequence_multi(tmpbuf, tmpbuf_len,
                                                            LTC_ASN1_INTEGER, 1UL, key->N,
                                                            LTC_ASN1_INTEGER, 1UL, key->e,
                                                            LTC_ASN1_EOL,     0UL, NULL)) != CRYPT_OK) {
                          goto LBL_ERR;
                       }
                       key->type = PK_PUBLIC;
                       err = CRYPT_OK;
                       goto LBL_FREE;
                    }
                 }
                 l = l->next;
              } while(l);
           }
        }
     }
  
  
  LBL_ERR:
     rsa_free(key);
  
  LBL_FREE:
     if (decoded_list) der_free_sequence_flexi(decoded_list);
     if (tmpbuf != NULL) XFREE(tmpbuf);
  
     return err;
  }
  
  #endif /* LTC_MRSA */
  
  
  /* ref:         $Format:%D$ */
  /* git commit:  $Format:%H$ */
  /* commit time: $Format:%ai$ */
  