--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtomcrypt/src/pk/dsa/dsa_set_pqg_dsaparam.c	Fri Feb 09 21:44:05 2018 +0800
@@ -0,0 +1,67 @@
+/* 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"
+
+
+#ifdef LTC_MDSA
+
+/**
+  Import DSA's p, q & g from dsaparam
+
+      dsaparam data: openssl dsaparam -outform DER -out dsaparam.der 2048
+
+  @param dsaparam    The DSA param DER encoded data
+  @param dsaparamlen The length of dhparam data
+  @param key         [out] the destination for the imported key
+  @return CRYPT_OK if successful.
+*/
+int dsa_set_pqg_dsaparam(const unsigned char *dsaparam, unsigned long dsaparamlen,
+                         dsa_key *key)
+{
+   int err, stat;
+
+   LTC_ARGCHK(dsaparam    != NULL);
+   LTC_ARGCHK(key         != NULL);
+   LTC_ARGCHK(ltc_mp.name != NULL);
+
+   /* init key */
+   err = mp_init_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL);
+   if (err != CRYPT_OK) return err;
+
+   if ((err = der_decode_sequence_multi(dsaparam, dsaparamlen,
+                                        LTC_ASN1_INTEGER, 1UL, key->p,
+                                        LTC_ASN1_INTEGER, 1UL, key->q,
+                                        LTC_ASN1_INTEGER, 1UL, key->g,
+                                        LTC_ASN1_EOL,     0UL, NULL)) != CRYPT_OK) {
+      goto LBL_ERR;
+   }
+
+   key->qord = mp_unsigned_bin_size(key->q);
+
+   /* quick p, q, g validation, without primality testing */
+   if ((err = dsa_int_validate_pqg(key, &stat)) != CRYPT_OK) {
+      goto LBL_ERR;
+   }
+   if (stat == 0) {
+      err = CRYPT_INVALID_PACKET;
+      goto LBL_ERR;
+   }
+
+   return CRYPT_OK;
+
+LBL_ERR:
+   dsa_free(key);
+   return err;
+}
+
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */