X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/898a4e2555438ff8adb08b4d82690d08715e1048..b817bfc642225b8c3c0b6a7e42d1fb949b61a606:/rsa-priv.c

diff --git a/rsa-priv.c b/rsa-priv.c
index a529f0b..8869ca4 100644
--- a/rsa-priv.c
+++ b/rsa-priv.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: rsa-priv.c,v 1.3 2001/06/16 12:56:38 mdw Exp $
+ * $Id: rsa-priv.c,v 1.4 2004/04/08 01:36:15 mdw Exp $
  *
  * RSA private-key operations
  *
@@ -27,31 +27,6 @@
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: rsa-priv.c,v $
- * Revision 1.3  2001/06/16 12:56:38  mdw
- * Fixes for interface change to @mpmont_expr@ and @mpmont_mexpr@.
- *
- * Revision 1.2  2000/10/08 12:11:22  mdw
- * Use @MP_EQ@ instead of @MP_CMP@.
- *
- * Revision 1.1  2000/07/01 11:23:20  mdw
- * Renamed from `rsa-decrypt', since the name was no longer appropriate.
- * Add functions for doing padded RSA decryption and signing.
- *
- * --- Previous lives as rsa-decrypt.c ---
- *
- * Revision 1.2  2000/06/17 11:57:56  mdw
- * Improve bulk performance by making better use of Montgomery
- * multiplication and separating out initialization and finalization from
- * the main code.
- *
- * Revision 1.1  1999/12/22 15:50:45  mdw
- * Initial RSA support.
- *
- */
-
 /*----- Header files ------------------------------------------------------*/
 
 #include <mLib/alloc.h>
@@ -228,82 +203,59 @@ mp *rsa_qprivop(rsa_priv *rp, mp *d, mp *c, grand *r)
 /* --- @rsa_sign@ --- *
  *
  * Arguments:	@rsa_privctx *rp@ = pointer to an RSA private key context
+ *		@mp *d@ = where to put the result
  *		@const void *m@ = pointer to input message
- *		@size_t sz@ = size of input message
- *		@dstr *d@ = pointer to output string
- *		@rsa_encodeproc e@ = encoding procedure
+ *		@size_t msz@ = size of input message
+ *		@rsa_pad *e@ = encoding procedure
  *		@void *earg@ = argument pointer for encoding procedure
  *
- * Returns:	The length of the output string if successful, negative on
+ * Returns:	The signature, as a multiprecision integer, or null on
  *		failure.
  *
  * Use:		Computes an RSA digital signature.
  */
 
-int rsa_sign(rsa_privctx *rp, const void *m, size_t sz,
-	     dstr *d, rsa_encodeproc e, void *earg)
+mp *rsa_sign(rsa_privctx *rp, mp *d, const void *m, size_t msz,
+	     rsa_pad *e, void *earg)
 {
-  mp *x;
-  size_t n = mp_octets(rp->rp->n);
   octet *p;
-  int rc;
-
-  /* --- Sort out some space --- */
-
-  dstr_ensure(d, n);
-  p = (octet *)d->buf + d->len;
-  p[0] = 0;
-
-  /* --- Do the packing --- */
-
-  if ((rc = e(m, sz, p, n, earg)) < 0)
-    return (rc);
-
-  /* --- Do the encryption --- */
-
-  x = mp_loadb(MP_NEWSEC, p, n);
-  x = rsa_privop(rp, x, x);
-  mp_storeb(x, p, n);
-  d->len += n;
-  mp_drop(x);
-  return (n);
+  unsigned long nb = mp_bits(rp->rp->n);
+  size_t n = (nb + 7)/8;
+  arena *a = d && d->a ? d->a->a : arena_global;
+
+  p = x_alloc(a, n);
+  d = e(d, m, msz, p, n, nb, earg);
+  x_free(a, p);
+  return (d ? rsa_privop(rp, d, d) : 0);
 }
 
 /* --- @rsa_decrypt@ --- *
  *
  * Arguments:	@rsa_privctx *rp@ = pointer to an RSA private key context
- *		@const void *m@ = pointer to input message
- *		@size_t sz@ = size of input message
+ *		@mp *m@ = encrypted message, as a multiprecision integer
  *		@dstr *d@ = pointer to output string
- *		@rsa_decodeproc e@ = decoding procedure
+ *		@rsa_decunpad *e@ = decoding procedure
  *		@void *earg@ = argument pointer for decoding procedure
  *
  * Returns:	The length of the output string if successful, negative on
  *		failure.
  *
- * Use:		Does RSA signature verification.
+ * Use:		Does RSA decryption.
  */
 
-int rsa_decrypt(rsa_privctx *rp, const void *m, size_t sz,
-	       dstr *d, rsa_decodeproc e, void *earg)
+int rsa_decrypt(rsa_privctx *rp, mp *m, dstr *d,
+		rsa_decunpad *e, void *earg)
 {
-  mp *x;
-  size_t n = mp_octets(rp->rp->n);
-  octet *p;
+  mp *p = rsa_privop(rp, MP_NEW, m);
+  unsigned long nb = mp_bits(rp->rp->n);
+  size_t n = (nb + 7)/8;
   int rc;
 
-  /* --- Do the exponentiation --- */
-
-  p = x_alloc(d->a, n);
-  x = mp_loadb(MP_NEW, m, sz);
-  x = rsa_privop(rp, x, x);
-  mp_storeb(x, p, n);
-  mp_drop(x);
-
-  /* --- Do the decoding --- */
-
-  rc = e(p, n, d, earg);
-  x_free(d->a, p);
+  dstr_ensure(d, n);
+  rc = e(p, (octet *)d->buf + d->len, n, nb, earg);
+  if (rc >= 0)
+    d->len += rc;
+  mp_drop(p);
   return (rc);
 }