X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=chiark-tcl.git;a=blobdiff_plain;f=crypto%2Fcrypto.c;h=97f4d1db06c16e79d8804d2392859f8bc85fdae0;hp=214b7fbde7256ea5869c3dc4b4395e8fd969d6a1;hb=0bc58e49b2b0700cd43a530b4d03112f9ad2441c;hpb=aa983421528c717a29c402c0cb4c8438b96fd860

diff --git a/crypto/crypto.c b/crypto/crypto.c
index 214b7fb..97f4d1d 100644
--- 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");
+    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);
   }
 
-  if (meth->pad) {
-    padlen= blocksize - (hbytes_len(v.hb) % blocksize);
-    padding= hbytes_append(v.hb, padlen);
+  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:;
+
+  }
+
+  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;
@@ -58,18 +136,27 @@ int do_hbytes_pkcs5(ClientData cd, Tcl_Interp *ip,
   return TCL_OK;
 }
 
+int do_hbytes_hash(ClientData cd, Tcl_Interp *ip, const HashAlgInfo *alg,
+		   HBytes_Value message, HBytes_Value *result) {
+  Byte *dest;
+
+  dest= hbytes_arrayspace(result,alg->hashsize);
+  alg->oneshot(dest, hbytes_data(&message), hbytes_len(&message));
+  return TCL_OK;
+}
+
 #define OBJ_CIPHKEY(o) ((CiphKeyValue*)(o)->internalRep.otherValuePtr)
 
 typedef struct {
   int valuelen, bufferslen;
   Byte *value, *buffers;
-  const BlockCipherAlgInfo *alg;
-  void *encrypt, *decrypt; /* key schedules; each may be 0 */
+  const void *alg;
+  void *alpha, *beta; /* key schedules etc.; each may be 0 */
 } CiphKeyValue;
 
 static void freealg(CiphKeyValue *key) {
-  TFREE(key->encrypt);
-  TFREE(key->decrypt);
+  TFREE(key->alpha);
+  TFREE(key->beta);
 }
 
 static void key_t_free(Tcl_Obj *obj) {
@@ -81,7 +168,7 @@ static void key_t_free(Tcl_Obj *obj) {
 
 static void noalg(CiphKeyValue *key) {
   key->alg= 0;
-  key->encrypt= key->decrypt= 0;
+  key->alpha= key->beta= 0;
 }
 
 static void key_t_dup(Tcl_Obj *src_obj, Tcl_Obj *dup_obj) {
@@ -93,6 +180,7 @@ static void key_t_dup(Tcl_Obj *src_obj, Tcl_Obj *dup_obj) {
   memcpy(dup->value, src->value, src->valuelen);
   noalg(dup);
   dup_obj->internalRep.otherValuePtr= dup;
+  dup_obj->typePtr= &blockcipherkey_type;
 }
 
 static void key_t_ustr(Tcl_Obj *o) {
@@ -124,72 +212,242 @@ Tcl_ObjType blockcipherkey_type = {
   key_t_free, key_t_dup, key_t_ustr, key_t_sfa
 };
 
-int do_hbytes_blockciph(ClientData cd, Tcl_Interp *ip, int encrypt,
-			HBytes_Var v, const BlockCipherAlgInfo *alg,
-			Tcl_Obj *key_obj, const BlockCipherModeInfo *mode,
-			HBytes_Value iv, HBytes_Value *result) {
-  int rc, want_bufferslen, data_len, iv_want;
+static CiphKeyValue *get_key(Tcl_Interp *ip, Tcl_Obj *key_obj,
+			     const void *alg, int want_bufferslen) {
   CiphKeyValue *key;
-  const char *failure;
-  void *sched, **schedp;
-
-  rc= Tcl_ConvertToType(ip,key_obj,&blockcipherkey_type);  if (rc) return rc;
+  int rc;
+  
+  rc= Tcl_ConvertToType(ip,key_obj,&blockcipherkey_type);  if (rc) return 0;
   key= OBJ_CIPHKEY(key_obj);
 
   if (key->alg != alg) {
     freealg(key);
     noalg(key);
-
-    if (key->valuelen < alg->key_min) return staticerr(ip, "key too short");
-    if (key->valuelen > alg->key_max) return staticerr(ip, "key too long");
     key->alg= alg;
   }
+  
+  if (key->bufferslen < want_bufferslen) {
+    TFREE(key->buffers);
+    key->buffers= TALLOC(want_bufferslen);
+    key->bufferslen= want_bufferslen;
+  }
+  return key;
+}
+
+int do_hbytes_blockcipher(ClientData cd, Tcl_Interp *ip,
+			  const BlockCipherOp *op,
+			  int objc, Tcl_Obj *const *objv) {
+  return op->func((void*)op,ip,objc,objv);
+}
+
+static int blockcipher_prep(Tcl_Interp *ip, Tcl_Obj *key_obj,
+			    const HBytes_Value *iv, int decrypt,
+			    const BlockCipherAlgInfo *alg,
+			    const BlockCipherModeInfo *mode, int data_len,
+			    const CiphKeyValue **key_r, const void **sched_r,
+			    const Byte **iv_r, int *iv_lenbytes_r,
+			    Byte **buffers_r, int *nblocks_r) {
+  void *sched, **schedp;
+  int want_bufferslen, want_iv;
+  int rc;
+  CiphKeyValue *key;
+
+  if (data_len % alg->blocksize)
+    return staticerr(ip, "block cipher input not whole number of blocks",
+		     "HBYTES BLOCKCIPHER LENGTH");
+
+  want_bufferslen= alg->blocksize * (mode->buf_blocks + mode->iv_blocks);
+  key= get_key(ip, key_obj, alg, want_bufferslen);  if (!key) return TCL_ERROR;
 
-  schedp= (alg->decrypt.make_schedule!=alg->encrypt.make_schedule
-	   && !encrypt) ? &key->decrypt : &key->encrypt;
+  schedp= (alg->decrypt.make_schedule==alg->encrypt.make_schedule
+	   || !decrypt) ? &key->alpha : &key->beta;
   sched= *schedp;
   if (!sched) {
+    if (key->valuelen < alg->key_min)
+      return staticerr(ip, "key too short", "HBYTES BLOCKCIPHER PARAMS");
+    if (key->valuelen > alg->key_max)
+      return staticerr(ip, "key too long", "HBYTES BLOCKCIPHER PARAMS");
+
     sched= TALLOC(alg->schedule_size);
-    (encrypt ? &alg->encrypt : &alg->decrypt)->make_schedule
+    (decrypt ? &alg->decrypt : &alg->encrypt)->make_schedule
       (sched, key->value, key->valuelen);
     *schedp= sched;
   }
-  
-  want_bufferslen= alg->blocksize * (mode->buf_blocks + mode->iv_blocks);
-  if (key->bufferslen < want_bufferslen) {
-    TFREE(key->buffers);
-    key->buffers= TALLOC(want_bufferslen);
-    key->bufferslen= want_bufferslen;
-  }
 
-  iv_want= alg->blocksize * mode->iv_blocks;
-  if (hbytes_issentinel(&iv)) {
-    if (!encrypt) return staticerr(ip,"must supply iv when decrypting");
-    rc= get_urandom(ip, key->buffers, iv_want);
+  want_iv= alg->blocksize * mode->iv_blocks;
+  if (!want_iv) {
+    if (!hbytes_issentinel(iv))
+      return staticerr(ip,"iv supplied but mode does not take one", 0);
+  } else if (hbytes_issentinel(iv)) {
+    if (decrypt) return staticerr(ip,"must supply iv when decrypting", 0);
+    rc= get_urandom(ip, key->buffers, want_iv);
     if (rc) return rc;
   } else {
-    int iv_supplied= hbytes_len(&iv);
-    if (iv_supplied > iv_want)
-      return staticerr(ip, "iv too large for algorithm and mode");
-    memcpy(key->buffers, hbytes_data(&iv), iv_supplied);
-    memset(key->buffers + iv_supplied, 0, iv_want - iv_supplied);
+    int iv_supplied= hbytes_len(iv);
+    if (iv_supplied > want_iv)
+      return staticerr(ip, "iv too large for algorithm and mode",
+		       "HBYTES BLOCKCIPHER PARAMS");
+    memcpy(key->buffers, hbytes_data(iv), iv_supplied);
+    memset(key->buffers + iv_supplied, 0, want_iv - iv_supplied);
   }
 
-  data_len= hbytes_len(v.hb);
-  if (data_len % alg->blocksize)
-    return staticerr(ip, "block cipher input not whole number of blocks");
+  *key_r= key;
+  *sched_r= sched;
+
+  *iv_r= key->buffers;
+  *iv_lenbytes_r= want_iv;
 
+  *buffers_r= key->buffers + want_iv;
+  *nblocks_r= data_len / alg->blocksize;
+  
+  return TCL_OK;
+}
+
+int do_blockcipherop_d(ClientData cd, Tcl_Interp *ip,
+		       HBytes_Var v, const BlockCipherAlgInfo *alg,
+		       Tcl_Obj *key_obj, const BlockCipherModeInfo *mode,
+		       HBytes_Value iv, HBytes_Value *result) {
+  return do_blockcipherop_e(cd,ip,v,alg,key_obj,mode,iv,result);
+}
+
+int do_blockcipherop_e(ClientData cd, Tcl_Interp *ip,
+		       HBytes_Var v, const BlockCipherAlgInfo *alg,
+		       Tcl_Obj *key_obj, const BlockCipherModeInfo *mode,
+		       HBytes_Value iv, HBytes_Value *result) {
+  const BlockCipherOp *op= (const void*)cd;
+  int encrypt= op->encrypt;
+  int rc, iv_lenbytes;
+  const CiphKeyValue *key;
+  const char *failure;
+  const Byte *ivbuf;
+  Byte *buffers;
+  const void *sched;
+  int nblocks;
+
+  if (!mode->encrypt)
+    return staticerr(ip, "mode does not support encrypt/decrypt", 0);
+
+  rc= blockcipher_prep(ip,key_obj,&iv,!encrypt,
+		       alg,mode, hbytes_len(v.hb),
+		       &key,&sched,
+		       &ivbuf,&iv_lenbytes,
+		       &buffers,&nblocks);
+  if (rc) return rc;
+  
   failure=
     (encrypt ? mode->encrypt : mode->decrypt)
-    (hbytes_data(v.hb), data_len / alg->blocksize,
-     key->buffers, key->buffers + iv_want,
-     alg, encrypt,
-     alg->blocksize, sched);
+    (hbytes_data(v.hb), nblocks, ivbuf, buffers, alg, encrypt, sched);
+
+  if (failure)
+    return staticerr(ip, failure, "HBYTES BLOCKCIPHER CRYPTFAIL CRYPT");
+
+  hbytes_array(result, ivbuf, iv_lenbytes);
+
+  return TCL_OK;
+}
 
+int do_blockcipherop_mac(ClientData cd, Tcl_Interp *ip,
+			 HBytes_Value msg, const BlockCipherAlgInfo *alg,
+			 Tcl_Obj *key_obj, const BlockCipherModeInfo *mode,
+			 HBytes_Value iv, HBytes_Value *result) {
+  const CiphKeyValue *key;
+  const char *failure;
+  const Byte *ivbuf;
+  Byte *buffers;
+  const void *sched;
+  int nblocks, iv_lenbytes;
+  int rc;
+
+  if (!mode->mac)
+    return staticerr(ip, "mode does not support mac generation", 0);
+  
+  rc= blockcipher_prep(ip,key_obj,&iv,0,
+		       alg,mode, hbytes_len(&msg),
+		       &key,&sched,
+		       &ivbuf,&iv_lenbytes,
+		       &buffers,&nblocks);
+  if (rc) return rc;
+
+  failure= mode->mac(hbytes_data(&msg), nblocks, ivbuf, buffers, alg, sched);
   if (failure)
-    return staticerr(ip, failure);
+    return staticerr(ip,failure, "HBYTES BLOCKCIPHER CRYPTFAIL MAC");
+
+  hbytes_array(result, buffers, alg->blocksize * mode->mac_blocks);
+
+  return TCL_OK;
+}
+
+int do_hbytes_hmac(ClientData cd, Tcl_Interp *ip, const HashAlgInfo *alg,
+		   HBytes_Value message, Tcl_Obj *key_obj,
+		   Tcl_Obj *maclen_obj, HBytes_Value *result) {
+  /* key->alpha = state after H(K XOR ipad <unfinished>
+   * key->beta = state after H(K XOR opad <unfinished>
+   * key->buffers = room for one block, or one state
+   */
+  CiphKeyValue *key;
+  Byte *dest;
+  int i, ml, rc;
+
+  if (maclen_obj) {
+    rc= Tcl_GetIntFromObj(ip, maclen_obj, &ml);  if (rc) return rc;
+    if (ml<0 || ml>alg->hashsize)
+      return staticerr(ip, "requested hmac output size out of range",
+		       "HBYTES HMAC PARAMS");
+  } else {
+    ml= alg->hashsize;
+  }
+
+  key= get_key(ip, key_obj, alg,
+	       alg->blocksize > alg->statesize
+	       ? alg->blocksize : alg->statesize);
 
-  hbytes_array(result, key->buffers, iv_want);
+  if (!key->alpha) {
+    assert(!key->beta);
+    
+    if (key->valuelen > alg->blocksize)
+      return staticerr(ip, "key to hmac longer than hash block size",
+		       "HBYTES HMAC PARAMS");
+
+    memcpy(key->buffers, key->value, key->valuelen);
+    memset(key->buffers + key->valuelen, 0, alg->blocksize - key->valuelen);
+    for (i=0; i<alg->blocksize; i++) key->buffers[i] ^= 0x36;
+
+    key->alpha= TALLOC(alg->statesize);
+    alg->init(key->alpha);
+    alg->update(key->alpha, key->buffers, alg->blocksize);
+    
+    key->beta= TALLOC(alg->statesize);
+    alg->init(key->beta);
+    for (i=0; i<alg->blocksize; i++) key->buffers[i] ^= (0x5c ^ 0x36);
+    alg->update(key->beta, key->buffers, alg->blocksize);
+  }
+  assert(key->beta);
+
+  dest= hbytes_arrayspace(result, alg->hashsize);
+
+  memcpy(key->buffers, key->alpha, alg->statesize);
+  alg->update(key->buffers, hbytes_data(&message), hbytes_len(&message));
+  alg->final(key->buffers, dest);
+
+  memcpy(key->buffers, key->beta, alg->statesize);
+  alg->update(key->buffers, dest, alg->hashsize);
+  alg->final(key->buffers, dest);
+
+  hbytes_unappend(result, alg->hashsize - ml);
+
+  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;
 }