--- /dev/null
+/* -*-c-*-
+ *
+ * PKCS#1 1.5 packing
+ *
+ * (c) 2000 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <string.h>
+
+#include <mLib/bits.h>
+#include <mLib/dstr.h>
+
+#include "ct.h"
+#include "grand.h"
+#include "rsa.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @pkcs1_cryptencode@ --- *
+ *
+ * Arguments: @mp *d@ = where to put the answer
+ * @const void *m@ = pointer to message data
+ * @size_t msz@ = size of message data
+ * @octet *b@ = spare buffer
+ * @size_t sz@ = size of the buffer (big enough)
+ * @unsigned long nbits@ = length of bits of @n@
+ * @void *p@ = pointer to PKCS1 parameter block
+ *
+ * Returns: The encoded result, or null.
+ *
+ * Use: Implements the operation @EME-PKCS1-V1_5-ENCODE@, as defined
+ * in PKCS#1 v. 2.0 (RFC2437).
+ */
+
+mp *pkcs1_cryptencode(mp *d, const void *m, size_t msz, octet *b, size_t sz,
+ unsigned long nbits, void *p)
+{
+ pkcs1 *pp = p;
+ grand *r = pp->r;
+ octet *q;
+ size_t i, n;
+
+ /* --- Ensure that the buffer is sensibly sized --- */
+
+ if (pp->epsz + msz + 11 > sz)
+ return (0);
+
+ /* --- Allocate the buffer and fill it in --- */
+
+ q = b;
+ *q++ = 0x00;
+ *q++ = 0x02;
+ n = sz - msz - pp->epsz - 3;
+ GR_FILL(r, q, n);
+ for (i = 0; i < n; i++) {
+ if (*q == 0)
+ *q = r->ops->range(r, 255) + 1;
+ q++;
+ }
+ *q++ = 0;
+ if (pp->ep) {
+ memcpy(q, pp->ep, pp->epsz);
+ q += pp->epsz;
+ }
+ memcpy(q, m, msz);
+ q += msz;
+ assert(q == b + sz);
+
+ /* --- Collect the result --- */
+
+ return (mp_loadb(d, b, sz));
+}
+
+/* --- @pkcs1_cryptdecode@ --- *
+ *
+ * Arguments: @mp *m@ = the decrypted message
+ * @octet *b@ = pointer to a buffer to work in
+ * @size_t sz@ = the size of the buffer (big enough)
+ * @unsigned long nbits@ = the number of bits in @n@
+ * @void *p@ = pointer to PKCS1 parameter block
+ *
+ * Returns: The length of the output string if successful, negative on
+ * failure.
+ *
+ * Use: Implements the operation @EME-PKCS1-V1_5-DECODE@, as defined
+ * in PKCS#1 v. 2.0 (RFC2437).
+ */
+
+int pkcs1_cryptdecode(mp *m, octet *b, size_t sz,
+ unsigned long nbits, void *p)
+{
+ pkcs1 *pp = p;
+ const octet *q, *qq;
+ size_t n, i;
+ uint32 goodp = 1;
+
+ /* --- Check the size of the block looks sane --- */
+
+ if (pp->epsz + 11 > sz) /* OK: independent of ciphertext */
+ return (-1);
+ mp_storeb(m, b, sz);
+ q = b;
+ qq = q + sz;
+
+ /* --- Ensure that the block looks OK --- */
+
+ goodp &= ct_inteq(*q++, 0);
+ goodp &= ct_inteq(*q++, 2);
+
+ /* --- Check the nonzero padding --- */
+
+ i = 0;
+ while (*q != 0 && q < qq)
+ i++, q++;
+ goodp &= ct_intle(8, i);
+ goodp &= ~ct_intle(qq - q, pp->epsz + 1);
+ q++;
+
+ /* --- Check the encoding parameters --- */
+
+ if (pp->ep)
+ goodp &= ct_memeq(b + ct_pick(goodp, 0, q - b), pp->ep, pp->epsz);
+ q += pp->epsz;
+
+ /* --- Done --- */
+
+ n = qq - q;
+ memmove(b, b + ct_pick(goodp, 1, q - b), n);
+ return (goodp ? n : -1);
+}
+
+/* --- @pkcs1_sigencode@ --- *
+ *
+ * Arguments: @mp *d@ = where to put the answer
+ * @const void *m@ = pointer to message data
+ * @size_t msz@ = size of message data
+ * @octet *b@ = spare buffer
+ * @size_t sz@ = size of the buffer (big enough)
+ * @unsigned long nbits@ = length of bits of @n@
+ * @void *p@ = pointer to PKCS1 parameter block
+ *
+ * Returns: The encoded message representative, or null.
+ *
+ * Use: Implements the operation @EMSA-PKCS1-V1_5-ENCODE@, as defined
+ * in PKCS#1 v. 2.0 (RFC2437).
+ */
+
+mp *pkcs1_sigencode(mp *d, const void *m, size_t msz, octet *b, size_t sz,
+ unsigned long nbits, void *p)
+{
+ pkcs1 *pp = p;
+ octet *q;
+ size_t n;
+
+ /* --- Ensure that the buffer is sensibly sized --- */
+
+ if (pp->epsz + msz + 11 > sz)
+ return (0);
+
+ /* --- Fill in the buffer --- */
+
+ q = b;
+ *q++ = 0x00;
+ *q++ = 0x01;
+ n = sz - msz - pp->epsz - 3;
+ memset(q, 0xff, n);
+ q += n;
+ *q++ = 0;
+ if (pp->ep) {
+ memcpy(q, pp->ep, pp->epsz);
+ q += pp->epsz;
+ }
+ memcpy(q, m, msz);
+ q += msz;
+ assert(q == b + sz);
+ return (mp_loadb(d, b, sz));
+}
+
+/* --- @pkcs1_sigdecode@ --- *
+ *
+ * Arguments: @mp *s@ = the message representative
+ * @const void *m@ = the original message, or null (ignored)
+ * @size_t msz@ = the message size (ignored)
+ * @octet *b@ = a scratch buffer
+ * @size_t sz@ = size of the buffer (large enough)
+ * @unsigned long nbits@ = number of bits in @n@
+ * @void *p@ = pointer to PKCS1 parameters
+ *
+ * Returns: The length of the output string if successful, negative on
+ * failure.
+ *
+ * Use: Implements the operation @EMSA-PKCS1-V1_5-DECODE@, as defined
+ * in PKCS#1 v. 2.0 (RFC2437).
+ */
+
+int pkcs1_sigdecode(mp *s, const void *m, size_t msz, octet *b, size_t sz,
+ unsigned long nbits, void *p)
+{
+ pkcs1 *pp = p;
+ const octet *q, *qq;
+ size_t i, n;
+
+ /* --- Check the size of the block looks sane --- */
+
+ if (pp->epsz + 10 > sz)
+ return (-1);
+ mp_storeb(s, b, sz);
+ q = b;
+ qq = q + sz;
+
+ /* --- Ensure that the block looks OK --- */
+
+ if (*q++ != 0x00 || *q++ != 0x01)
+ return (-1);
+
+ /* --- Check the padding --- */
+
+ i = 0;
+ while (*q == 0xff && q < qq)
+ i++, q++;
+ if (i < 8 || qq - q < pp->epsz + 1 || *q++ != 0)
+ return (-1);
+
+ /* --- Check the encoding parameters --- */
+
+ if (pp->ep && memcmp(q, pp->ep, pp->epsz) != 0)
+ return (-1);
+ q += pp->epsz;
+
+ /* --- Done --- */
+
+ n = qq - q;
+ memmove(b, q, n);
+ return (n);
+}
+
+/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff