pd.if.org Git - zpackage/blob - libtomcrypt/src/pk/rsa/rsa_import_x509.c

   1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
   2  *
   3  * LibTomCrypt is a library that provides various cryptographic
   4  * algorithms in a highly modular and flexible manner.
   5  *
   6  * The library is free for all purposes without any express
   7  * guarantee it works.
   8  */
   9 #include "tomcrypt.h"
  10
  11 /**
  12   @file rsa_import.c
  13   Import an RSA key from a X.509 certificate, Steffen Jaeckel
  14 */
  15
  16 #ifdef LTC_MRSA
  17
  18 /**
  19   Import an RSA key from a X.509 certificate
  20   @param in      The packet to import from
  21   @param inlen   It's length (octets)
  22   @param key     [out] Destination for newly imported key
  23   @return CRYPT_OK if successful, upon error allocated memory is freed
  24 */
  25 int rsa_import_x509(const unsigned char *in, unsigned long inlen, rsa_key *key)
  26 {
  27    int           err;
  28    unsigned char *tmpbuf;
  29    unsigned long tmpbuf_len, tmp_inlen;
  30    ltc_asn1_list *decoded_list = NULL, *l;
  31
  32    LTC_ARGCHK(in          != NULL);
  33    LTC_ARGCHK(key         != NULL);
  34    LTC_ARGCHK(ltc_mp.name != NULL);
  35
  36    /* init key */
  37    if ((err = mp_init_multi(&key->e, &key->d, &key->N, &key->dQ,
  38                             &key->dP, &key->qP, &key->p, &key->q, NULL)) != CRYPT_OK) {
  39       return err;
  40    }
  41
  42    tmpbuf_len = inlen;
  43    tmpbuf = XCALLOC(1, tmpbuf_len);
  44    if (tmpbuf == NULL) {
  45        err = CRYPT_MEM;
  46        goto LBL_ERR;
  47    }
  48
  49    tmp_inlen = inlen;
  50    if ((err = der_decode_sequence_flexi(in, &tmp_inlen, &decoded_list)) == CRYPT_OK) {
  51       l = decoded_list;
  52       /* Move 2 levels up in the tree
  53          SEQUENCE
  54              SEQUENCE
  55                  ...
  56        */
  57       if (l->type == LTC_ASN1_SEQUENCE && l->child) {
  58          l = l->child;
  59          if (l->type == LTC_ASN1_SEQUENCE && l->child) {
  60             l = l->child;
  61
  62             err = CRYPT_ERROR;
  63
  64             /* Move forward in the tree until we find this combination
  65                  ...
  66                  SEQUENCE
  67                      SEQUENCE
  68                          OBJECT IDENTIFIER 1.2.840.113549.1.1.1
  69                          NULL
  70                      BIT STRING
  71              */
  72             do {
  73                /* The additional check for l->data is there to make sure
  74                 * we won't try to decode a list that has been 'shrunk'
  75                 */
  76                if (l->type == LTC_ASN1_SEQUENCE && l->data && l->child &&
  77                      l->child->type == LTC_ASN1_SEQUENCE && l->child->child &&
  78                      l->child->child->type == LTC_ASN1_OBJECT_IDENTIFIER && l->child->next &&
  79                      l->child->next->type == LTC_ASN1_BIT_STRING) {
  80                   err = der_decode_subject_public_key_info(l->data, l->size,
  81                        PKA_RSA, tmpbuf, &tmpbuf_len,
  82                        LTC_ASN1_NULL, NULL, 0);
  83                   if (err == CRYPT_OK) {
  84                      /* now it should be SEQUENCE { INTEGER, INTEGER } */
  85                      if ((err = der_decode_sequence_multi(tmpbuf, tmpbuf_len,
  86                                                           LTC_ASN1_INTEGER, 1UL, key->N,
  87                                                           LTC_ASN1_INTEGER, 1UL, key->e,
  88                                                           LTC_ASN1_EOL,     0UL, NULL)) != CRYPT_OK) {
  89                         goto LBL_ERR;
  90                      }
  91                      key->type = PK_PUBLIC;
  92                      err = CRYPT_OK;
  93                      goto LBL_FREE;
  94                   }
  95                }
  96                l = l->next;
  97             } while(l);
  98          }
  99       }
 100    }
 101
 102
 103 LBL_ERR:
 104    rsa_free(key);
 105
 106 LBL_FREE:
 107    if (decoded_list) der_free_sequence_flexi(decoded_list);
 108    if (tmpbuf != NULL) XFREE(tmpbuf);
 109
 110    return err;
 111 }
 112
 113 #endif /* LTC_MRSA */
 114
 115
 116 /* ref:         $Format:%D$ */
 117 /* git commit:  $Format:%H$ */
 118 /* commit time: $Format:%ai$ */