gutting this to put it in chiark-tcl

[chiark-tcl.git] / crypto / crypto.c

diff --git a/crypto/crypto.c b/crypto/crypto.c
index 1fc1f8336bfe65cf14b5934987ac11c0f7d1ba93..97f4d1db06c16e79d8804d2392859f8bc85fdae0 100644 (file)
--- a/crypto/crypto.c
+++ b/crypto/crypto.c
@@ -5,13 +5,12 @@
 
 #include "hbytes.h"
 #include "tables.h"
-#include "serpent.h"
 
 void memxor(Byte *dest, const Byte *src, int l) {
   while (l--) *dest++ ^= *src++;
 }
 
-const PadMethod padmethods[]= {
+const PadOp padops[]= {
   { "un", 0, 0 },
   { "ua", 0, 1 },
   { "pn", 1, 0 },
@@ -19,35 +18,114 @@ const PadMethod padmethods[]= {
   { 0 }
 };
 
-int do_hbytes_pkcs5(ClientData cd, Tcl_Interp *ip,
-                   const PadMethod *meth, HBytes_Var v, Tcl_Obj *block,
-                   int *ok) {
-  int rc, blocksize, padlen, old_len, i;
-  Byte *padding;
-  const Byte *unpad;
+typedef struct {
+  HBytes_Value *hb;
+  int pad, blocksize; /* 0 or 1 */
+} PadMethodClientData;
+
+int do_hbytes_pad(ClientData cd, Tcl_Interp *ip, const PadOp *op,
+                 HBytes_Var v, Tcl_Obj *blocksz, const PadMethodInfo *meth,
+                 int methargsc, Tcl_Obj *const *methargsv) {
+  PadMethodClientData pmcd;
+  int rc;
   
-  if (meth->use_algname) {
+  if (op->use_algname) {
     const BlockCipherAlgInfo *alg;
-    alg= enum_lookup_cached(ip,block,blockcipheralginfos,"cipher alg for pad");
+    alg= enum_lookup_cached(ip,blocksz,blockcipheralginfos,
+                           "blockcipher alg for pad");
     if (!alg) return TCL_ERROR;
-    blocksize= alg->blocksize;
+    pmcd.blocksize= alg->blocksize;
   } else {
-    rc= Tcl_GetIntFromObj(ip, block, &blocksize);  if (rc) return rc;
-    if (blocksize < 1 || blocksize > 255)
-      return staticerr(ip, "block size out of pkcs#5 range 1..255", 0);
+    rc= Tcl_GetIntFromObj(ip, blocksz, &pmcd.blocksize);  if (rc) return rc;
+    if (pmcd.blocksize < 1) staticerr(ip, "block size must be at least 1", 0);
+  }
+
+  pmcd.hb= v.hb;
+  pmcd.pad= op->pad;
+
+  return meth->func(&pmcd,ip,methargsc,methargsv);
+}
+  
+int do_padmethodinfo_rfc2406(ClientData cd, Tcl_Interp *ip,
+                            Tcl_Obj *nxthdr_arg, int *ok) {
+  const PadMethodClientData *pmcd= (const void*)cd;
+  int i, rc, padlen, old_len;
+  
+  if (pmcd->blocksize > 256)
+    return staticerr(ip, "block size too large for RFC2406 padding", 0);
+
+  if (pmcd->pad) {
+    Byte *padding;
+    HBytes_Value nxthdr;
+
+    rc= pat_hb(ip,nxthdr_arg,&nxthdr);
+    if (rc) return rc;
+
+    if (hbytes_len(&nxthdr) != 1) return
+      staticerr(ip, "RFC2406 next header field must be exactly 1 byte", 0);
+    padlen= pmcd->blocksize-1 - ((hbytes_len(pmcd->hb)+1) % pmcd->blocksize);
+    padding= hbytes_append(pmcd->hb, padlen+2);
+    for (i=1; i<=padlen; i++)
+      *padding++ = i;
+    *padding++ = padlen;
+    *padding++ = hbytes_data(&nxthdr)[0];
+    *ok= 1;
+    
+  } else {
+    const Byte *padding, *trailer;
+    HBytes_Value nxthdr;
+    Tcl_Obj *nxthdr_valobj, *ro;
+    
+    *ok= 0;
+    old_len= hbytes_len(pmcd->hb);  if (old_len % pmcd->blocksize) goto quit;
+    trailer= hbytes_unappend(pmcd->hb, 2); if (!trailer) goto quit;
+
+    padlen= trailer[0];
+    hbytes_array(&nxthdr,trailer+1,1);
+    nxthdr_valobj= ret_hb(ip,nxthdr);
+    ro= Tcl_ObjSetVar2(ip,nxthdr_arg,0,nxthdr_valobj,TCL_LEAVE_ERR_MSG);
+    if (!ro) { Tcl_DecrRefCount(nxthdr_valobj); return TCL_ERROR; }
+
+    padding= hbytes_unappend(pmcd->hb, padlen);
+    for (i=1; i<=padlen; i++)
+      if (*padding++ != i) goto quit;
+
+    *ok= 1;
+
+  quit:;
+
   }
 
-  if (meth->pad) {
-    padlen= blocksize - (hbytes_len(v.hb) % blocksize);
-    padding= hbytes_append(v.hb, padlen);
+  return TCL_OK;
+}
+
+int do_padmethodinfo_pkcs5(ClientData cd, Tcl_Interp *ip, int *ok) {
+  const PadMethodClientData *pmcd= (const void*)cd;
+  int padlen, old_len, i;
+  
+  if (pmcd->blocksize > 255)
+    return staticerr(ip, "block size too large for pkcs#5", 0);
+
+  if (pmcd->pad) {
+
+    Byte *padding;
+
+    padlen= pmcd->blocksize - (hbytes_len(pmcd->hb) % pmcd->blocksize);
+    padding= hbytes_append(pmcd->hb, padlen);
     memset(padding, padlen, padlen);
+
   } else {
-    old_len= hbytes_len(v.hb);  if (old_len % blocksize) goto bad;
-    unpad= hbytes_unappend(v.hb, 1);  if (!unpad) goto bad;
-    padlen= *unpad;
-    if (padlen < 1 || padlen > blocksize) goto bad;
-    unpad= hbytes_unappend(v.hb, padlen-1);  if (!unpad) goto bad;
-    for (i=0; i<padlen-1; i++, unpad++) if (*unpad != padlen) goto bad;
+
+    const Byte *padding;
+
+    old_len= hbytes_len(pmcd->hb);  if (old_len % pmcd->blocksize) goto bad;
+    padding= hbytes_unappend(pmcd->hb, 1);  if (!padding) goto bad;
+    padlen= *padding;
+    if (padlen < 1 || padlen > pmcd->blocksize) goto bad;
+    padding= hbytes_unappend(pmcd->hb, padlen-1);  if (!padding) goto bad;
+
+    for (i=0; i<padlen-1; i++, padding++) if (*padding != padlen) goto bad;
+
   }
 
   *ok= 1;
@@ -359,3 +437,17 @@ int do_hbytes_hmac(ClientData cd, Tcl_Interp *ip, const HashAlgInfo *alg,
 
   return TCL_OK;
 }
+
+int do_blockcipherop_prop(ClientData cd, Tcl_Interp *ip,
+                         const BlockCipherPropInfo *prop,
+                         const BlockCipherAlgInfo *alg, int *result) {
+  *result= *(const int*)((const char*)alg + prop->int_offset);
+  return TCL_OK;
+}
+
+int do_hbytes_hash_prop(ClientData cd, Tcl_Interp *ip,
+                       const HashAlgPropInfo *prop,
+                       const HashAlgInfo *alg, int *result) {
+  *result= *(const int*)((const char*)alg + prop->int_offset);
+  return TCL_OK;
+}