1 files changed, 92 insertions, 0 deletions
diff --git a/src/pk/rsa/rsa_import.c b/src/pk/rsa/rsa_import.c
new file mode 100644
index 0000000..5706134
--- /dev/null
+++ b/src/pk/rsa/rsa_import.c
@@ -0,0 +1,92 @@
+/* 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.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/**
+  @file rsa_import.c
+  Import a PKCS RSA key, Tom St Denis
+*/  
+
+#ifdef MRSA
+
+/**
+  Import an RSAPublicKey or RSAPrivateKey [two-prime only, only support >= 1024-bit keys, defined in PKCS #1 v2.1]
+  @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(const unsigned char *in, unsigned long inlen, rsa_key *key)
+{
+   int           err;
+   mp_int        zero;
+
+   LTC_ARGCHK(in  != NULL);
+   LTC_ARGCHK(key != NULL);
+
+   /* init key */
+   if ((err = mp_init_multi(&zero, &key->e, &key->d, &key->N, &key->dQ, 
+                            &key->dP, &key->qP, &key->p, &key->q, NULL)) != MP_OKAY) {
+      return mpi_to_ltc_error(err);
+   }
+
+   if ((err = der_decode_sequence_multi(in, inlen, 
+                                  LTC_ASN1_INTEGER, 1UL, &key->N, 
+                                  LTC_ASN1_EOL,     0UL, NULL)) != CRYPT_OK) {
+      goto LBL_ERR;
+   }
+
+   if (mp_cmp_d(&key->N, 0) == MP_EQ) {
+      /* it's a private key */
+      if ((err = der_decode_sequence_multi(in, inlen, 
+                          LTC_ASN1_INTEGER, 1UL, &zero, 
+                          LTC_ASN1_INTEGER, 1UL, &key->N, 
+                          LTC_ASN1_INTEGER, 1UL, &key->e,
+                          LTC_ASN1_INTEGER, 1UL, &key->d, 
+                          LTC_ASN1_INTEGER, 1UL, &key->p, 
+                          LTC_ASN1_INTEGER, 1UL, &key->q, 
+                          LTC_ASN1_INTEGER, 1UL, &key->dP,
+                          LTC_ASN1_INTEGER, 1UL, &key->dQ, 
+                          LTC_ASN1_INTEGER, 1UL, &key->qP, 
+                          LTC_ASN1_EOL,     0UL, NULL)) != CRYPT_OK) {
+         goto LBL_ERR;
+      }
+      key->type = PK_PRIVATE;
+   } else if (mp_cmp_d(&key->N, 1) == MP_EQ) {
+      /* we don't support multi-prime RSA */
+      err = CRYPT_PK_INVALID_TYPE;
+      goto LBL_ERR;
+   } else {
+      /* it's a public key and we lack e */
+      if ((err = der_decode_sequence_multi(in, inlen, 
+                                     LTC_ASN1_INTEGER, 1UL, &key->N, 
+                                     LTC_ASN1_INTEGER, 1UL, &key->e, 
+                                     LTC_ASN1_EOL,     0UL, NULL)) != CRYPT_OK) {
+         goto LBL_ERR;
+      }
+
+      /* free up some ram */
+      mp_clear_multi(&key->p, &key->q, &key->qP, &key->dP, &key->dQ, NULL);
+      key->type = PK_PUBLIC;
+   }
+   return CRYPT_OK;
+LBL_ERR:
+   mp_clear_multi(&zero, &key->d, &key->e, &key->N, &key->dQ, &key->dP,
+                  &key->qP, &key->p, &key->q, NULL);
+   return err;
+}
+
+#endif /* MRSA */
+
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/rsa/rsa_import.c,v $ */
+/* $Revision: 1.10 $ */
+/* $Date: 2005/06/03 18:48:28 $ */