Implement s4u extensions

Merge Luke's users/lhoward/s4u branch to trunk.  Implements S4U2Self
and S4U2Proxy extensions.

ticket: 6563

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@22736 dc483132-0cff-0310-8789-dd5450dbe970

7 files changed, 1214 insertions, 0 deletions

diff --git a/src/lib/crypto/krb/enc_provider/Makefile.in b/src/lib/crypto/krb/enc_provider/Makefile.in
new file mode 100644
index 0000000..2eedf1d
--- /dev/null
+++ b/src/lib/crypto/krb/enc_provider/Makefile.in
@@ -0,0 +1,41 @@
+thisconfigdir=../../../..
+myfulldir=lib/crypto/krb/enc_provider
+mydir=lib/crypto/krb/enc_provider
+BUILDTOP=$(REL)..$(S)..$(S)..$(S)..
+LOCALINCLUDES = -I$(srcdir)/../../@CRYPTO_IMPL@/des -I$(srcdir)/../../@CRYPTO_IMPL@/arcfour 	\
+		-I$(srcdir)/../../@CRYPTO_IMPL@/aes -I$(srcdir)/.. -I$(srcdir)/../../@CRYPTO_IMPL@ 
+DEFS=
+
+##DOS##BUILDTOP = ..\..\..\..
+##DOS##PREFIXDIR=enc_provider
+##DOS##OBJFILE=..\$(OUTPRE)enc_prov.lst
+
+PROG_LIBPATH=-L$(TOPLIBD)
+PROG_RPATH=$(KRB5_LIBDIR)
+
+STLIBOBJS= des.o des3.o rc4.o aes.o 
+
+OBJS= \
+	$(OUTPRE)des.$(OBJEXT) \
+	$(OUTPRE)des3.$(OBJEXT) \
+	$(OUTPRE)aes.$(OBJEXT) \
+	$(OUTPRE)rc4.$(OBJEXT)
+
+SRCS= \
+	$(srcdir)/des.c \
+	$(srcdir)/des3.c \
+	$(srcdir)/aes.c \
+	$(srcdir)/rc4.c
+
+##DOS##LIBOBJS = $(OBJS)
+
+all-unix:: all-libobjs
+
+includes:: depend
+
+depend:: $(SRCS)
+
+clean-unix:: clean-libobjs
+
+@libobj_frag@
+
diff --git a/src/lib/crypto/krb/enc_provider/aes.c b/src/lib/crypto/krb/enc_provider/aes.c
new file mode 100644
index 0000000..060d119
--- /dev/null
+++ b/src/lib/crypto/krb/enc_provider/aes.c
@@ -0,0 +1,415 @@
+/*
+ * lib/crypto/enc_provider/aes.c
+ *
+ * Copyright (C) 2003, 2007, 2008 by the Massachusetts Institute of Technology.
+ * All rights reserved.
+ *
+ * Export of this software from the United States of America may
+ *   require a specific license from the United States Government.
+ *   It is the responsibility of any person or organization contemplating
+ *   export to obtain such a license before exporting.
+ *
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of M.I.T. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  Furthermore if you modify this software you must label
+ * your software as modified software and not distribute it in such a
+ * fashion that it might be confused with the original M.I.T. software.
+ * M.I.T. makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ */
+
+#include "k5-int.h"
+#include "enc_provider.h"
+#include "aes.h"
+#include "../aead.h"
+
+#if 0
+aes_rval aes_blk_len(unsigned int blen, aes_ctx cx[1]);
+aes_rval aes_enc_key(const unsigned char in_key[], unsigned int klen, aes_ctx cx[1]);
+aes_rval aes_enc_blk(const unsigned char in_blk[], unsigned char out_blk[], const aes_ctx cx[1]);
+aes_rval aes_dec_key(const unsigned char in_key[], unsigned int klen, aes_ctx cx[1]);
+aes_rval aes_dec_blk(const unsigned char in_blk[], unsigned char out_blk[], const aes_ctx cx[1]);
+#endif
+
+#define CHECK_SIZES 0
+
+#if 0
+static void printd (const char *descr, krb5_data *d) {
+    int i, j;
+    const int r = 16;
+
+    printf("%s:", descr);
+
+    for (i = 0; i < d->length; i += r) {
+	printf("\n  %04x: ", i);
+	for (j = i; j < i + r && j < d->length; j++)
+	    printf(" %02x", 0xff & d->data[j]);
+#ifdef SHOW_TEXT
+	for (; j < i + r; j++)
+	    printf("   ");
+	printf("   ");
+	for (j = i; j < i + r && j < d->length; j++) {
+	    int c = 0xff & d->data[j];
+	    printf("%c", isprint(c) ? c : '.');
+	}
+#endif
+    }
+    printf("\n");
+}
+#endif
+
+static inline void enc(char *out, const char *in, aes_ctx *ctx)
+{
+    if (aes_enc_blk((const unsigned char *)in, (unsigned char *)out, ctx)
+	!= aes_good)
+	abort();
+}
+static inline void dec(char *out, const char *in, aes_ctx *ctx)
+{
+    if (aes_dec_blk((const unsigned char *)in, (unsigned char *)out, ctx)
+	!= aes_good)
+	abort();
+}
+
+static void xorblock(char *out, const char *in)
+{
+    int z;
+    for (z = 0; z < BLOCK_SIZE; z++)
+	out[z] ^= in[z];
+}
+
+krb5_error_code
+krb5int_aes_encrypt(const krb5_keyblock *key, const krb5_data *ivec,
+		    const krb5_data *input, krb5_data *output)
+{
+    aes_ctx ctx;
+    char tmp[BLOCK_SIZE], tmp2[BLOCK_SIZE], tmp3[BLOCK_SIZE];
+    int nblocks = 0, blockno;
+
+/*    CHECK_SIZES; */
+
+    if (aes_enc_key(key->contents, key->length, &ctx) != aes_good)
+	abort();
+
+    if (ivec)
+	memcpy(tmp, ivec->data, BLOCK_SIZE);
+    else
+	memset(tmp, 0, BLOCK_SIZE);
+
+    nblocks = (input->length + BLOCK_SIZE - 1) / BLOCK_SIZE;
+
+    if (nblocks == 1) {
+	/* XXX Used for DK function.  */
+	enc(output->data, input->data, &ctx);
+    } else {
+	unsigned int nleft;
+
+	for (blockno = 0; blockno < nblocks - 2; blockno++) {
+	    xorblock(tmp, input->data + blockno * BLOCK_SIZE);
+	    enc(tmp2, tmp, &ctx);
+	    memcpy(output->data + blockno * BLOCK_SIZE, tmp2, BLOCK_SIZE);
+
+	    /* Set up for next block.  */
+	    memcpy(tmp, tmp2, BLOCK_SIZE);
+	}
+	/* Do final CTS step for last two blocks (the second of which
+	   may or may not be incomplete).  */
+	xorblock(tmp, input->data + (nblocks - 2) * BLOCK_SIZE);
+	enc(tmp2, tmp, &ctx);
+	nleft = input->length - (nblocks - 1) * BLOCK_SIZE;
+	memcpy(output->data + (nblocks - 1) * BLOCK_SIZE, tmp2, nleft);
+	memcpy(tmp, tmp2, BLOCK_SIZE);
+
+	memset(tmp3, 0, sizeof(tmp3));
+	memcpy(tmp3, input->data + (nblocks - 1) * BLOCK_SIZE, nleft);
+	xorblock(tmp, tmp3);
+	enc(tmp2, tmp, &ctx);
+	memcpy(output->data + (nblocks - 2) * BLOCK_SIZE, tmp2, BLOCK_SIZE);
+	if (ivec)
+	    memcpy(ivec->data, tmp2, BLOCK_SIZE);
+    }
+
+    return 0;
+}
+
+krb5_error_code
+krb5int_aes_decrypt(const krb5_keyblock *key, const krb5_data *ivec,
+		    const krb5_data *input, krb5_data *output)
+{
+    aes_ctx ctx;
+    char tmp[BLOCK_SIZE], tmp2[BLOCK_SIZE], tmp3[BLOCK_SIZE];
+    int nblocks = 0, blockno;
+
+    CHECK_SIZES;
+
+    if (aes_dec_key(key->contents, key->length, &ctx) != aes_good)
+	abort();
+
+    if (ivec)
+	memcpy(tmp, ivec->data, BLOCK_SIZE);
+    else
+	memset(tmp, 0, BLOCK_SIZE);
+
+    nblocks = (input->length + BLOCK_SIZE - 1) / BLOCK_SIZE;
+
+    if (nblocks == 1) {
+	if (input->length < BLOCK_SIZE)
+	    abort();
+	dec(output->data, input->data, &ctx);
+    } else {
+
+	for (blockno = 0; blockno < nblocks - 2; blockno++) {
+	    dec(tmp2, input->data + blockno * BLOCK_SIZE, &ctx);
+	    xorblock(tmp2, tmp);
+	    memcpy(output->data + blockno * BLOCK_SIZE, tmp2, BLOCK_SIZE);
+	    memcpy(tmp, input->data + blockno * BLOCK_SIZE, BLOCK_SIZE);
+	}
+	/* Do last two blocks, the second of which (next-to-last block
+	   of plaintext) may be incomplete.  */
+	dec(tmp2, input->data + (nblocks - 2) * BLOCK_SIZE, &ctx);
+	/* Set tmp3 to last ciphertext block, padded.  */
+	memset(tmp3, 0, sizeof(tmp3));
+	memcpy(tmp3, input->data + (nblocks - 1) * BLOCK_SIZE,
+	       input->length - (nblocks - 1) * BLOCK_SIZE);
+	/* Set tmp2 to last (possibly partial) plaintext block, and
+	   save it.  */
+	xorblock(tmp2, tmp3);
+	memcpy(output->data + (nblocks - 1) * BLOCK_SIZE, tmp2,
+	       input->length - (nblocks - 1) * BLOCK_SIZE);
+	/* Maybe keep the trailing part, and copy in the last
+	   ciphertext block.  */
+	memcpy(tmp2, tmp3, input->length - (nblocks - 1) * BLOCK_SIZE);
+	/* Decrypt, to get next to last plaintext block xor previous
+	   ciphertext.  */
+	dec(tmp3, tmp2, &ctx);
+	xorblock(tmp3, tmp);
+	memcpy(output->data + (nblocks - 2) * BLOCK_SIZE, tmp3, BLOCK_SIZE);
+	if (ivec)
+	    memcpy(ivec->data, input->data + (nblocks - 2) * BLOCK_SIZE,
+		   BLOCK_SIZE);
+    }
+
+    return 0;
+}
+
+static krb5_error_code
+krb5int_aes_encrypt_iov(const krb5_keyblock *key,
+		        const krb5_data *ivec,
+		        krb5_crypto_iov *data,
+		        size_t num_data)
+{
+    aes_ctx ctx;
+    char tmp[BLOCK_SIZE], tmp2[BLOCK_SIZE];
+    int nblocks = 0, blockno;
+    size_t input_length, i;
+
+    if (aes_enc_key(key->contents, key->length, &ctx) != aes_good)
+	abort();
+
+    if (ivec != NULL)
+	memcpy(tmp, ivec->data, BLOCK_SIZE);
+    else
+	memset(tmp, 0, BLOCK_SIZE);
+
+    for (i = 0, input_length = 0; i < num_data; i++) {
+	krb5_crypto_iov *iov = &data[i];
+
+	if (ENCRYPT_IOV(iov))
+	    input_length += iov->data.length;
+    }
+
+    nblocks = (input_length + BLOCK_SIZE - 1) / BLOCK_SIZE;
+
+    assert(nblocks > 1);
+
+    {
+	char blockN2[BLOCK_SIZE];   /* second last */
+	char blockN1[BLOCK_SIZE];   /* last block */
+	struct iov_block_state input_pos, output_pos;
+
+	IOV_BLOCK_STATE_INIT(&input_pos);
+	IOV_BLOCK_STATE_INIT(&output_pos);
+
+	for (blockno = 0; blockno < nblocks - 2; blockno++) {
+	    char blockN[BLOCK_SIZE];
+
+	    krb5int_c_iov_get_block((unsigned char *)blockN, BLOCK_SIZE, data, num_data, &input_pos);
+	    xorblock(tmp, blockN);
+	    enc(tmp2, tmp, &ctx);
+	    krb5int_c_iov_put_block(data, num_data, (unsigned char *)tmp2, BLOCK_SIZE, &output_pos);
+
+	    /* Set up for next block.  */
+	    memcpy(tmp, tmp2, BLOCK_SIZE);
+	}
+
+	/* Do final CTS step for last two blocks (the second of which
+	   may or may not be incomplete).  */
+
+	/* First, get the last two blocks */
+	memset(blockN1, 0, sizeof(blockN1)); /* pad last block with zeros */
+	krb5int_c_iov_get_block((unsigned char *)blockN2, BLOCK_SIZE, data, num_data, &input_pos);
+	krb5int_c_iov_get_block((unsigned char *)blockN1, BLOCK_SIZE, data, num_data, &input_pos);
+
+	/* Encrypt second last block */
+	xorblock(tmp, blockN2);
+	enc(tmp2, tmp, &ctx);
+	memcpy(blockN2, tmp2, BLOCK_SIZE); /* blockN2 now contains first block */
+	memcpy(tmp, tmp2, BLOCK_SIZE);
+
+	/* Encrypt last block */
+	xorblock(tmp, blockN1);
+	enc(tmp2, tmp, &ctx);
+	memcpy(blockN1, tmp2, BLOCK_SIZE);
+
+	/* Put the last two blocks back into the iovec (reverse order) */
+	krb5int_c_iov_put_block(data, num_data, (unsigned char *)blockN1, BLOCK_SIZE, &output_pos);
+	krb5int_c_iov_put_block(data, num_data, (unsigned char *)blockN2, BLOCK_SIZE, &output_pos);
+
+	if (ivec != NULL)
+	    memcpy(ivec->data, blockN1, BLOCK_SIZE);
+    }
+
+    return 0;
+}
+
+static krb5_error_code
+krb5int_aes_decrypt_iov(const krb5_keyblock *key,
+		        const krb5_data *ivec,
+		        krb5_crypto_iov *data,
+		        size_t num_data)
+{
+    aes_ctx ctx;
+    char tmp[BLOCK_SIZE], tmp2[BLOCK_SIZE], tmp3[BLOCK_SIZE];
+    int nblocks = 0, blockno;
+    unsigned int i;
+    size_t input_length;
+
+    CHECK_SIZES;
+
+    if (aes_dec_key(key->contents, key->length, &ctx) != aes_good)
+	abort();
+
+    if (ivec != NULL)
+	memcpy(tmp, ivec->data, BLOCK_SIZE);
+    else
+	memset(tmp, 0, BLOCK_SIZE);
+
+    for (i = 0, input_length = 0; i < num_data; i++) {
+	krb5_crypto_iov *iov = &data[i];
+
+	if (ENCRYPT_IOV(iov))
+	    input_length += iov->data.length;
+    }
+
+    nblocks = (input_length + BLOCK_SIZE - 1) / BLOCK_SIZE;
+
+    assert(nblocks > 1);
+
+    {
+	char blockN2[BLOCK_SIZE];   /* second last */
+	char blockN1[BLOCK_SIZE];   /* last block */
+	struct iov_block_state input_pos, output_pos;
+
+	IOV_BLOCK_STATE_INIT(&input_pos);
+	IOV_BLOCK_STATE_INIT(&output_pos);
+
+	for (blockno = 0; blockno < nblocks - 2; blockno++) {
+	    char blockN[BLOCK_SIZE];
+
+	    krb5int_c_iov_get_block((unsigned char *)blockN, BLOCK_SIZE, data, num_data, &input_pos);
+	    dec(tmp2, blockN, &ctx);
+	    xorblock(tmp2, tmp);
+	    krb5int_c_iov_put_block(data, num_data, (unsigned char *)tmp2, BLOCK_SIZE, &output_pos);
+	    memcpy(tmp, blockN, BLOCK_SIZE);
+	}
+
+	/* Do last two blocks, the second of which (next-to-last block
+	   of plaintext) may be incomplete.  */
+
+	/* First, get the last two encrypted blocks */
+	memset(blockN1, 0, sizeof(blockN1)); /* pad last block with zeros */
+	krb5int_c_iov_get_block((unsigned char *)blockN2, BLOCK_SIZE, data, num_data, &input_pos);
+	krb5int_c_iov_get_block((unsigned char *)blockN1, BLOCK_SIZE, data, num_data, &input_pos);
+
+	/* Decrypt second last block */
+	dec(tmp2, blockN2, &ctx);
+	/* Set tmp2 to last (possibly partial) plaintext block, and
+	   save it.  */
+	xorblock(tmp2, blockN1);
+	memcpy(blockN2, tmp2, BLOCK_SIZE);
+
+	/* Maybe keep the trailing part, and copy in the last
+	   ciphertext block.  */
+	input_length %= BLOCK_SIZE;
+	memcpy(tmp2, blockN1, input_length ? input_length : BLOCK_SIZE);
+	dec(tmp3, tmp2, &ctx);
+	xorblock(tmp3, tmp);
+	/* Copy out ivec first before we clobber blockN1 with plaintext */
+	if (ivec != NULL)
+	    memcpy(ivec->data, blockN1, BLOCK_SIZE);
+	memcpy(blockN1, tmp3, BLOCK_SIZE);
+
+	/* Put the last two blocks back into the iovec */
+	krb5int_c_iov_put_block(data, num_data, (unsigned char *)blockN1, BLOCK_SIZE, &output_pos);
+	krb5int_c_iov_put_block(data, num_data, (unsigned char *)blockN2, BLOCK_SIZE, &output_pos);
+    }
+
+    return 0;
+}
+
+static krb5_error_code
+k5_aes_make_key(const krb5_data *randombits, krb5_keyblock *key)
+{
+    if (key->length != 16 && key->length != 32)
+	return(KRB5_BAD_KEYSIZE);
+    if (randombits->length != key->length)
+	return(KRB5_CRYPTO_INTERNAL);
+
+    key->magic = KV5M_KEYBLOCK;
+
+    memcpy(key->contents, randombits->data, randombits->length);
+    return(0);
+}
+
+static krb5_error_code
+krb5int_aes_init_state (const krb5_keyblock *key, krb5_keyusage usage,
+			krb5_data *state)
+{
+    state->length = 16;
+    state->data = (void *) malloc(16);
+    if (state->data == NULL)
+	return ENOMEM;
+    memset(state->data, 0, state->length);
+    return 0;
+}
+
+const struct krb5_enc_provider krb5int_enc_aes128 = {
+    16,
+    16, 16,
+    krb5int_aes_encrypt,
+    krb5int_aes_decrypt,
+    k5_aes_make_key,
+    krb5int_aes_init_state,
+    krb5int_default_free_state,
+    krb5int_aes_encrypt_iov,
+    krb5int_aes_decrypt_iov
+};
+
+const struct krb5_enc_provider krb5int_enc_aes256 = {
+    16,
+    32, 32,
+    krb5int_aes_encrypt,
+    krb5int_aes_decrypt,
+    k5_aes_make_key,
+    krb5int_aes_init_state,
+    krb5int_default_free_state,
+    krb5int_aes_encrypt_iov,
+    krb5int_aes_decrypt_iov
+};
+
diff --git a/src/lib/crypto/krb/enc_provider/deps b/src/lib/crypto/krb/enc_provider/deps
new file mode 100644
index 0000000..0649762
--- /dev/null
+++ b/src/lib/crypto/krb/enc_provider/deps
@@ -0,0 +1,49 @@
+# 
+# Generated makefile dependencies follow.
+#
+des.so des.po $(OUTPRE)des.$(OBJEXT): $(BUILDTOP)/include/autoconf.h \
+  $(BUILDTOP)/include/krb5/krb5.h $(BUILDTOP)/include/osconf.h \
+  $(BUILDTOP)/include/profile.h $(COM_ERR_DEPS) $(SRCTOP)/include/k5-buf.h \
+  $(SRCTOP)/include/k5-err.h $(SRCTOP)/include/k5-gmt_mktime.h \
+  $(SRCTOP)/include/k5-int-pkinit.h $(SRCTOP)/include/k5-int.h \
+  $(SRCTOP)/include/k5-platform.h $(SRCTOP)/include/k5-plugin.h \
+  $(SRCTOP)/include/k5-thread.h $(SRCTOP)/include/krb5.h \
+  $(SRCTOP)/include/krb5/locate_plugin.h $(SRCTOP)/include/krb5/preauth_plugin.h \
+  $(SRCTOP)/include/port-sockets.h $(SRCTOP)/include/socket-utils.h \
+  $(srcdir)/../../builtin/des/des_int.h $(srcdir)/../aead.h \
+  $(srcdir)/../cksumtypes.h des.c enc_provider.h
+des3.so des3.po $(OUTPRE)des3.$(OBJEXT): $(BUILDTOP)/include/autoconf.h \
+  $(BUILDTOP)/include/krb5/krb5.h $(BUILDTOP)/include/osconf.h \
+  $(BUILDTOP)/include/profile.h $(COM_ERR_DEPS) $(SRCTOP)/include/k5-buf.h \
+  $(SRCTOP)/include/k5-err.h $(SRCTOP)/include/k5-gmt_mktime.h \
+  $(SRCTOP)/include/k5-int-pkinit.h $(SRCTOP)/include/k5-int.h \
+  $(SRCTOP)/include/k5-platform.h $(SRCTOP)/include/k5-plugin.h \
+  $(SRCTOP)/include/k5-thread.h $(SRCTOP)/include/krb5.h \
+  $(SRCTOP)/include/krb5/locate_plugin.h $(SRCTOP)/include/krb5/preauth_plugin.h \
+  $(SRCTOP)/include/port-sockets.h $(SRCTOP)/include/socket-utils.h \
+  $(srcdir)/../../builtin/des/des_int.h $(srcdir)/../aead.h \
+  $(srcdir)/../cksumtypes.h des3.c
+aes.so aes.po $(OUTPRE)aes.$(OBJEXT): $(BUILDTOP)/include/autoconf.h \
+  $(BUILDTOP)/include/krb5/krb5.h $(BUILDTOP)/include/osconf.h \
+  $(BUILDTOP)/include/profile.h $(COM_ERR_DEPS) $(SRCTOP)/include/k5-buf.h \
+  $(SRCTOP)/include/k5-err.h $(SRCTOP)/include/k5-gmt_mktime.h \
+  $(SRCTOP)/include/k5-int-pkinit.h $(SRCTOP)/include/k5-int.h \
+  $(SRCTOP)/include/k5-platform.h $(SRCTOP)/include/k5-plugin.h \
+  $(SRCTOP)/include/k5-thread.h $(SRCTOP)/include/krb5.h \
+  $(SRCTOP)/include/krb5/locate_plugin.h $(SRCTOP)/include/krb5/preauth_plugin.h \
+  $(SRCTOP)/include/port-sockets.h $(SRCTOP)/include/socket-utils.h \
+  $(srcdir)/../../builtin/aes/aes.h $(srcdir)/../../builtin/aes/uitypes.h \
+  $(srcdir)/../aead.h $(srcdir)/../cksumtypes.h aes.c \
+  enc_provider.h
+rc4.so rc4.po $(OUTPRE)rc4.$(OBJEXT): $(BUILDTOP)/include/autoconf.h \
+  $(BUILDTOP)/include/krb5/krb5.h $(BUILDTOP)/include/osconf.h \
+  $(BUILDTOP)/include/profile.h $(COM_ERR_DEPS) $(SRCTOP)/include/k5-buf.h \
+  $(SRCTOP)/include/k5-err.h $(SRCTOP)/include/k5-gmt_mktime.h \
+  $(SRCTOP)/include/k5-int-pkinit.h $(SRCTOP)/include/k5-int.h \
+  $(SRCTOP)/include/k5-platform.h $(SRCTOP)/include/k5-plugin.h \
+  $(SRCTOP)/include/k5-thread.h $(SRCTOP)/include/krb5.h \
+  $(SRCTOP)/include/krb5/locate_plugin.h $(SRCTOP)/include/krb5/preauth_plugin.h \
+  $(SRCTOP)/include/port-sockets.h $(SRCTOP)/include/socket-utils.h \
+  $(srcdir)/../../builtin/arcfour/arcfour-int.h $(srcdir)/../../builtin/arcfour/arcfour.h \
+  $(srcdir)/../aead.h $(srcdir)/../cksumtypes.h enc_provider.h \
+  rc4.c
diff --git a/src/lib/crypto/krb/enc_provider/des.c b/src/lib/crypto/krb/enc_provider/des.c
new file mode 100644
index 0000000..547f6b9
--- /dev/null
+++ b/src/lib/crypto/krb/enc_provider/des.c
@@ -0,0 +1,181 @@
+/*
+ * Copyright (C) 1998 by the FundsXpress, INC.
+ * 
+ * All rights reserved.
+ * 
+ * Export of this software from the United States of America may require
+ * a specific license from the United States Government.  It is the
+ * responsibility of any person or organization contemplating export to
+ * obtain such a license before exporting.
+ * 
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of FundsXpress. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  FundsXpress makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ * 
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include "k5-int.h"
+#include "des_int.h"
+#include "enc_provider.h"
+#include "aead.h"
+
+static krb5_error_code
+k5_des_docrypt(const krb5_keyblock *key, const krb5_data *ivec,
+	       const krb5_data *input, krb5_data *output, int enc)
+{
+    mit_des_key_schedule schedule;
+
+    /* key->enctype was checked by the caller */
+
+    if (key->length != 8)
+	return(KRB5_BAD_KEYSIZE);
+    if ((input->length%8) != 0)
+	return(KRB5_BAD_MSIZE);
+    if (ivec && (ivec->length != 8))
+	return(KRB5_BAD_MSIZE);
+    if (input->length != output->length)
+	return(KRB5_BAD_MSIZE);
+
+    switch (mit_des_key_sched(key->contents, schedule)) {
+    case -1:
+	return(KRB5DES_BAD_KEYPAR);
+    case -2:
+	return(KRB5DES_WEAK_KEY);
+    }
+
+    /* this has a return value, but the code always returns zero */
+
+    mit_des_cbc_encrypt((krb5_pointer) input->data,
+			(krb5_pointer) output->data, input->length,
+			schedule,
+			(ivec
+			 ? (const unsigned char *) ivec->data
+			 : (const unsigned char *) mit_des_zeroblock),
+			enc);
+
+    memset(schedule, 0, sizeof(schedule));
+
+    return(0);
+}
+
+static krb5_error_code
+k5_des_encrypt(const krb5_keyblock *key, const krb5_data *ivec,
+	       const krb5_data *input, krb5_data *output)
+{
+    return(k5_des_docrypt(key, ivec, input, output, 1));
+}
+
+static krb5_error_code
+k5_des_decrypt(const krb5_keyblock *key, const krb5_data *ivec,
+	       const krb5_data *input, krb5_data *output)
+{
+    return(k5_des_docrypt(key, ivec, input, output, 0));
+}
+
+static krb5_error_code
+k5_des_make_key(const krb5_data *randombits, krb5_keyblock *key)
+{
+    if (key->length != 8)
+	return(KRB5_BAD_KEYSIZE);
+    if (randombits->length != 7)
+	return(KRB5_CRYPTO_INTERNAL);
+
+    key->magic = KV5M_KEYBLOCK;
+    key->length = 8;
+
+    /* take the seven bytes, move them around into the top 7 bits of the
+       8 key bytes, then compute the parity bits */
+
+    memcpy(key->contents, randombits->data, randombits->length);
+    key->contents[7] = (((key->contents[0]&1)<<1) | ((key->contents[1]&1)<<2) |
+			((key->contents[2]&1)<<3) | ((key->contents[3]&1)<<4) |
+			((key->contents[4]&1)<<5) | ((key->contents[5]&1)<<6) |
+			((key->contents[6]&1)<<7));
+
+    mit_des_fixup_key_parity(key->contents);
+
+    return(0);
+}
+
+static krb5_error_code
+k5_des_docrypt_iov(const krb5_keyblock *key, const krb5_data *ivec,
+		   krb5_crypto_iov *data, size_t num_data, int enc)
+{
+    mit_des_key_schedule schedule;
+    size_t input_length = 0;
+    unsigned int i;
+
+    /* key->enctype was checked by the caller */
+
+    if (key->length != 8)
+	return(KRB5_BAD_KEYSIZE);
+
+    for (i = 0; i < num_data; i++) {
+	const krb5_crypto_iov *iov = &data[i];
+
+	if (ENCRYPT_DATA_IOV(iov))
+	    input_length += iov->data.length;
+    }
+
+    if ((input_length % 8) != 0)
+	return(KRB5_BAD_MSIZE);
+    if (ivec && (ivec->length != 8))
+	return(KRB5_BAD_MSIZE);
+
+    switch (mit_des_key_sched(key->contents, schedule)) {
+    case -1:
+	return(KRB5DES_BAD_KEYPAR);
+    case -2:
+	return(KRB5DES_WEAK_KEY);
+    }
+
+    /* this has a return value, but the code always returns zero */
+    if (enc)
+	krb5int_des_cbc_encrypt_iov(data, num_data, schedule, ivec ? ivec->data : NULL);
+    else
+	krb5int_des_cbc_decrypt_iov(data, num_data, schedule, ivec ? ivec->data : NULL);
+
+    memset(schedule, 0, sizeof(schedule));
+
+    return(0);
+}
+
+static krb5_error_code
+k5_des_encrypt_iov(const krb5_keyblock *key,
+		    const krb5_data *ivec,
+		    krb5_crypto_iov *data,
+		    size_t num_data)
+{
+    return k5_des_docrypt_iov(key, ivec, data, num_data, 1);
+}
+
+static krb5_error_code
+k5_des_decrypt_iov(const krb5_keyblock *key,
+		   const krb5_data *ivec,
+		   krb5_crypto_iov *data,
+		   size_t num_data)
+{
+    return k5_des_docrypt_iov(key, ivec, data, num_data, 0);
+}
+
+const struct krb5_enc_provider krb5int_enc_des = {
+    8,
+    7, 8,
+    k5_des_encrypt,
+    k5_des_decrypt,
+    k5_des_make_key,
+    krb5int_des_init_state,
+    krb5int_default_free_state,
+    k5_des_encrypt_iov,
+    k5_des_decrypt_iov
+};
diff --git a/src/lib/crypto/krb/enc_provider/des3.c b/src/lib/crypto/krb/enc_provider/des3.c
new file mode 100644
index 0000000..412c994
--- /dev/null
+++ b/src/lib/crypto/krb/enc_provider/des3.c
@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) 1998 by the FundsXpress, INC.
+ * 
+ * All rights reserved.
+ * 
+ * Export of this software from the United States of America may require
+ * a specific license from the United States Government.  It is the
+ * responsibility of any person or organization contemplating export to
+ * obtain such a license before exporting.
+ * 
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of FundsXpress. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  FundsXpress makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ * 
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include "k5-int.h"
+#include "des_int.h"
+#include "../aead.h"
+
+static krb5_error_code
+validate_and_schedule(const krb5_keyblock *key, const krb5_data *ivec,
+		      const krb5_data *input, const krb5_data *output,
+		      mit_des3_key_schedule *schedule)
+{
+    /* key->enctype was checked by the caller */
+
+    if (key->length != 24)
+	return(KRB5_BAD_KEYSIZE);
+    if ((input->length%8) != 0)
+	return(KRB5_BAD_MSIZE);
+    if (ivec && (ivec->length != 8))
+	return(KRB5_BAD_MSIZE);
+    if (input->length != output->length)
+	return(KRB5_BAD_MSIZE);
+
+    switch (mit_des3_key_sched(*(mit_des3_cblock *)key->contents,
+			       *schedule)) {
+    case -1:
+	return(KRB5DES_BAD_KEYPAR);
+    case -2:
+	return(KRB5DES_WEAK_KEY);
+    }
+    return 0;
+}
+
+static krb5_error_code
+validate_and_schedule_iov(const krb5_keyblock *key, const krb5_data *ivec,
+			  const krb5_crypto_iov *data, size_t num_data,
+			  mit_des3_key_schedule *schedule)
+{
+    size_t i, input_length;
+
+    for (i = 0, input_length = 0; i < num_data; i++) {
+	const krb5_crypto_iov *iov = &data[i];
+
+	if (ENCRYPT_IOV(iov))
+	    input_length += iov->data.length;
+    }
+
+    if (key->length != 24)
+	return(KRB5_BAD_KEYSIZE);
+    if ((input_length%8) != 0)
+	return(KRB5_BAD_MSIZE);
+    if (ivec && (ivec->length != 8))
+	return(KRB5_BAD_MSIZE);
+
+    switch (mit_des3_key_sched(*(mit_des3_cblock *)key->contents,
+			       *schedule)) {
+    case -1:
+	return(KRB5DES_BAD_KEYPAR);
+    case -2:
+	return(KRB5DES_WEAK_KEY);
+    }
+    return 0;
+}
+
+static krb5_error_code
+k5_des3_encrypt(const krb5_keyblock *key, const krb5_data *ivec,
+		const krb5_data *input, krb5_data *output)
+{
+    mit_des3_key_schedule schedule;
+    krb5_error_code err;
+
+    err = validate_and_schedule(key, ivec, input, output, &schedule);
+    if (err)
+	return err;
+
+    /* this has a return value, but the code always returns zero */
+    krb5int_des3_cbc_encrypt((krb5_pointer) input->data,
+			     (krb5_pointer) output->data, input->length,
+			     schedule[0], schedule[1], schedule[2],
+			     ivec?(const unsigned char *) ivec->data:(const unsigned char *)mit_des_zeroblock);
+
+    zap(schedule, sizeof(schedule));
+
+    return(0);
+}
+
+static krb5_error_code
+k5_des3_decrypt(const krb5_keyblock *key, const krb5_data *ivec,
+		const krb5_data *input, krb5_data *output)
+{
+    mit_des3_key_schedule schedule;
+    krb5_error_code err;
+
+    err = validate_and_schedule(key, ivec, input, output, &schedule);
+    if (err)
+	return err;
+
+    /* this has a return value, but the code always returns zero */
+    krb5int_des3_cbc_decrypt((krb5_pointer) input->data,
+			     (krb5_pointer) output->data, input->length,
+			     schedule[0], schedule[1], schedule[2],
+			     ivec?(const unsigned char *) ivec->data:(const unsigned char *)mit_des_zeroblock);
+
+    zap(schedule, sizeof(schedule));
+
+    return(0);
+}
+
+static krb5_error_code
+k5_des3_make_key(const krb5_data *randombits, krb5_keyblock *key)
+{
+    int i;
+
+    if (key->length != 24)
+	return(KRB5_BAD_KEYSIZE);
+    if (randombits->length != 21)
+	return(KRB5_CRYPTO_INTERNAL);
+
+    key->magic = KV5M_KEYBLOCK;
+    key->length = 24;
+
+    /* take the seven bytes, move them around into the top 7 bits of the
+       8 key bytes, then compute the parity bits.  Do this three times. */
+
+    for (i=0; i<3; i++) {
+	memcpy(key->contents+i*8, randombits->data+i*7, 7);
+	key->contents[i*8+7] = (((key->contents[i*8]&1)<<1) |
+				((key->contents[i*8+1]&1)<<2) |
+				((key->contents[i*8+2]&1)<<3) |
+				((key->contents[i*8+3]&1)<<4) |
+				((key->contents[i*8+4]&1)<<5) |
+				((key->contents[i*8+5]&1)<<6) |
+				((key->contents[i*8+6]&1)<<7));
+
+	mit_des_fixup_key_parity(key->contents+i*8);
+    }
+
+    return(0);
+}
+
+static krb5_error_code
+k5_des3_encrypt_iov(const krb5_keyblock *key,
+		    const krb5_data *ivec,
+		    krb5_crypto_iov *data,
+		    size_t num_data)
+{
+    mit_des3_key_schedule schedule;
+    krb5_error_code err;
+
+    err = validate_and_schedule_iov(key, ivec, data, num_data, &schedule);
+    if (err)
+	return err;
+
+    /* this has a return value, but the code always returns zero */
+    krb5int_des3_cbc_encrypt_iov(data, num_data,
+			     schedule[0], schedule[1], schedule[2],
+			     ivec != NULL ? (unsigned char *) ivec->data : NULL);
+
+    zap(schedule, sizeof(schedule));
+
+    return(0);
+}
+
+static krb5_error_code
+k5_des3_decrypt_iov(const krb5_keyblock *key,
+		    const krb5_data *ivec,
+		    krb5_crypto_iov *data,
+		    size_t num_data)
+{
+    mit_des3_key_schedule schedule;
+    krb5_error_code err;
+
+    err = validate_and_schedule_iov(key, ivec, data, num_data, &schedule);
+    if (err)
+	return err;
+
+    /* this has a return value, but the code always returns zero */
+    krb5int_des3_cbc_decrypt_iov(data, num_data,
+				 schedule[0], schedule[1], schedule[2],
+				 ivec != NULL ? (unsigned char *) ivec->data : NULL);
+
+    zap(schedule, sizeof(schedule));
+
+    return(0);
+}
+
+const struct krb5_enc_provider krb5int_enc_des3 = {
+    8,
+    21, 24,
+    k5_des3_encrypt,
+    k5_des3_decrypt,
+    k5_des3_make_key,
+    krb5int_des_init_state,
+    krb5int_default_free_state,
+    k5_des3_encrypt_iov,
+    k5_des3_decrypt_iov
+};
+
diff --git a/src/lib/crypto/krb/enc_provider/enc_provider.h b/src/lib/crypto/krb/enc_provider/enc_provider.h
new file mode 100644
index 0000000..92022b3
--- /dev/null
+++ b/src/lib/crypto/krb/enc_provider/enc_provider.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 1998 by the FundsXpress, INC.
+ * 
+ * All rights reserved.
+ * 
+ * Export of this software from the United States of America may require
+ * a specific license from the United States Government.  It is the
+ * responsibility of any person or organization contemplating export to
+ * obtain such a license before exporting.
+ * 
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of FundsXpress. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  FundsXpress makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ * 
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#include "k5-int.h"
+
+extern const struct krb5_enc_provider krb5int_enc_des;
+extern const struct krb5_enc_provider krb5int_enc_des3;
+extern const struct krb5_enc_provider krb5int_enc_arcfour;
+extern const struct krb5_enc_provider krb5int_enc_aes128;
+extern const struct krb5_enc_provider krb5int_enc_aes256;
+extern const struct krb5_enc_provider krb5int_enc_aes128_ctr;
+extern const struct krb5_enc_provider krb5int_enc_aes256_ctr;
+
diff --git a/src/lib/crypto/krb/enc_provider/rc4.c b/src/lib/crypto/krb/enc_provider/rc4.c
new file mode 100644
index 0000000..b950a60
--- /dev/null
+++ b/src/lib/crypto/krb/enc_provider/rc4.c
@@ -0,0 +1,271 @@
+/* arcfour.c 
+ *
+ * Copyright (c) 2000 by Computer Science Laboratory,
+ *                       Rensselaer Polytechnic Institute
+ *
+ * #include STD_DISCLAIMER
+ */
+
+#include "k5-int.h"
+#include "arcfour-int.h"
+#include "enc_provider.h"
+#include "../aead.h"
+/* gets the next byte from the PRNG */
+#if ((__GNUC__ >= 2) )
+static __inline__ unsigned int k5_arcfour_byte(ArcfourContext *);
+#else
+static unsigned int k5_arcfour_byte(ArcfourContext *);
+#endif /* gcc inlines*/
+
+/* Initializes the context and sets the key. */
+static krb5_error_code k5_arcfour_init(ArcfourContext *ctx, const unsigned char *key, 
+		  unsigned int keylen);
+
+/* Encrypts/decrypts data. */
+static void k5_arcfour_crypt(ArcfourContext *ctx, unsigned char *dest, 
+		     const unsigned char *src, unsigned int len);
+
+/* Interface layer to kerb5 crypto layer */
+static krb5_error_code
+k5_arcfour_docrypt(const krb5_keyblock *, const krb5_data *,
+		   const krb5_data *, krb5_data *);
+
+/* from a random bitstrem, construct a key */
+static krb5_error_code
+k5_arcfour_make_key(const krb5_data *, krb5_keyblock *);
+
+static const unsigned char arcfour_weakkey1[] = {0x00, 0x00, 0xfd};
+static const unsigned char arcfour_weakkey2[] = {0x03, 0xfd, 0xfc};
+static const struct {
+    size_t length;
+    const unsigned char *data;
+} arcfour_weakkeys[] = {
+    { sizeof (arcfour_weakkey1), arcfour_weakkey1},
+    { sizeof (arcfour_weakkey2), arcfour_weakkey2},
+};
+
+static inline unsigned int k5_arcfour_byte(ArcfourContext * ctx)
+{
+  unsigned int x;
+  unsigned int y;
+  unsigned int sx, sy;
+  unsigned char *state;
+
+  state = ctx->state;
+  x = (ctx->x + 1) & 0xff;
+  sx = state[x];
+  y = (sx + ctx->y) & 0xff;
+  sy = state[y];
+  ctx->x = x;
+  ctx->y = y;
+  state[y] = sx;
+  state[x] = sy;
+  return state[(sx + sy) & 0xff];
+}
+
+static void k5_arcfour_crypt(ArcfourContext *ctx, unsigned char *dest, 
+		     const unsigned char *src, unsigned int len)
+{
+  unsigned int i;
+  for (i = 0; i < len; i++)
+    dest[i] = src[i] ^ k5_arcfour_byte(ctx);
+}
+
+
+static krb5_error_code
+k5_arcfour_init(ArcfourContext *ctx, const unsigned char *key, 
+		  unsigned int key_len)
+{
+  unsigned int t, u;
+  unsigned int keyindex;
+  unsigned int stateindex;
+  unsigned char* state;
+  unsigned int counter;
+
+  if (key_len != 16)
+    return KRB5_BAD_MSIZE;     /*this is probably not the correct error code
+				 to return */
+  for (counter=0;
+       counter < sizeof(arcfour_weakkeys)/sizeof(arcfour_weakkeys[0]);
+       counter++)
+      if (!memcmp(key, arcfour_weakkeys[counter].data,
+		  arcfour_weakkeys[counter].length))
+	  return KRB5DES_WEAK_KEY; /* most certainly not the correct error */
+
+  state = &ctx->state[0];
+  ctx->x = 0;
+  ctx->y = 0;
+  for (counter = 0; counter < 256; counter++)
+    state[counter] = counter;
+  keyindex = 0;
+  stateindex = 0;
+  for (counter = 0; counter < 256; counter++)
+    {
+      t = state[counter];
+      stateindex = (stateindex + key[keyindex] + t) & 0xff;
+      u = state[stateindex];
+      state[stateindex] = t;
+      state[counter] = u;
+      if (++keyindex >= key_len)
+	keyindex = 0;
+    }
+  return 0;
+}
+
+
+/* The workhorse of the arcfour system, this impliments the cipher */
+static krb5_error_code
+k5_arcfour_docrypt(const krb5_keyblock *key, const krb5_data *state,
+	       const krb5_data *input, krb5_data *output)
+{
+  ArcfourContext *arcfour_ctx;
+  ArcFourCipherState *cipher_state;
+  int ret;
+
+  if (key->length != 16)
+    return(KRB5_BAD_KEYSIZE);
+  if (state && (state->length != sizeof (ArcFourCipherState)))
+    return(KRB5_BAD_MSIZE);
+  if (input->length != output->length)
+    return(KRB5_BAD_MSIZE);
+
+  if (state) {
+    cipher_state = (ArcFourCipherState *) state->data;
+    arcfour_ctx=&cipher_state->ctx;
+    if (cipher_state->initialized == 0) {
+      if ((ret=k5_arcfour_init(arcfour_ctx, key->contents, key->length))) {
+	return ret;
+      }
+      cipher_state->initialized = 1;
+    }
+    k5_arcfour_crypt(arcfour_ctx, (unsigned char *) output->data, (const unsigned char *) input->data, input->length);
+  }
+  else {
+    arcfour_ctx=malloc(sizeof (ArcfourContext));
+    if (arcfour_ctx == NULL)
+      return ENOMEM;
+    if ((ret=k5_arcfour_init(arcfour_ctx, key->contents, key->length))) {
+      free(arcfour_ctx);
+      return (ret);
+    }
+    k5_arcfour_crypt(arcfour_ctx, (unsigned char * ) output->data,
+		     (const unsigned char * ) input->data, input->length);
+    memset(arcfour_ctx, 0, sizeof (ArcfourContext));
+    free(arcfour_ctx);
+  }
+  
+  return 0;
+}
+
+/* In-place encryption */
+static krb5_error_code
+k5_arcfour_docrypt_iov(const krb5_keyblock *key,
+		       const krb5_data *state,
+		       krb5_crypto_iov *data,
+		       size_t num_data)
+{
+    ArcfourContext *arcfour_ctx = NULL;
+    ArcFourCipherState *cipher_state = NULL;
+    krb5_error_code ret;
+    size_t i;
+
+    if (key->length != 16)
+	return KRB5_BAD_KEYSIZE;
+    if (state != NULL && (state->length != sizeof(ArcFourCipherState)))
+	return KRB5_BAD_MSIZE;
+
+    if (state != NULL) {
+	cipher_state = (ArcFourCipherState *)state->data;
+	arcfour_ctx = &cipher_state->ctx;
+	if (cipher_state->initialized == 0) {
+	    ret = k5_arcfour_init(arcfour_ctx, key->contents, key->length);
+	    if (ret != 0)
+		return ret;
+
+	    cipher_state->initialized = 1;
+	}
+    } else {
+	arcfour_ctx = (ArcfourContext *)malloc(sizeof(ArcfourContext));
+	if (arcfour_ctx == NULL)
+	    return ENOMEM;
+
+	ret = k5_arcfour_init(arcfour_ctx, key->contents, key->length);
+	if (ret != 0) {
+	    free(arcfour_ctx);
+	    return ret;
+	}
+    }
+
+    for (i = 0; i < num_data; i++) {
+	krb5_crypto_iov *iov = &data[i];
+
+	if (ENCRYPT_IOV(iov))
+	    k5_arcfour_crypt(arcfour_ctx, (unsigned char *)iov->data.data,
+			     (const unsigned char *)iov->data.data, iov->data.length);
+    }
+
+    if (state == NULL) {
+	memset(arcfour_ctx, 0, sizeof(ArcfourContext));
+	free(arcfour_ctx);
+    }
+
+    return 0;
+}
+
+static krb5_error_code
+k5_arcfour_make_key(const krb5_data *randombits, krb5_keyblock *key)
+{
+    if (key->length != 16)
+	return(KRB5_BAD_KEYSIZE);
+    if (randombits->length != 16)
+	return(KRB5_CRYPTO_INTERNAL);
+
+    key->magic = KV5M_KEYBLOCK;
+    key->length = 16;
+
+    memcpy(key->contents, randombits->data, randombits->length);
+
+    return(0);
+}
+
+static krb5_error_code
+k5_arcfour_init_state (const krb5_keyblock *key,
+		       krb5_keyusage keyusage, krb5_data *new_state)
+{
+  /* Note that we can't actually set up the state here  because the key
+   * will change  between now and when encrypt is called
+   * because  it is data dependent.  Yeah, this has strange
+   * properties. --SDH
+   */
+  new_state->length = sizeof (ArcFourCipherState);
+  new_state->data = malloc (new_state->length);
+  if (new_state->data) {
+    memset (new_state->data, 0 , new_state->length);
+    /* That will set initialized to zero*/
+  }else {
+    return (ENOMEM);
+  }
+  return 0;
+}
+
+/* Since the arcfour cipher is identical going forwards and backwards, 
+   we just call "docrypt" directly
+*/
+const struct krb5_enc_provider krb5int_enc_arcfour = {
+    /* This seems to work... although I am not sure what the
+       implications are in other places in the kerberos library */
+    1,
+    /* Keysize is arbitrary in arcfour, but the constraints of the
+       system, and to attempt to work with the MSFT system forces us
+       to 16byte/128bit.  Since there is no parity in the key, the
+       byte and length are the same.  */
+    16, 16,
+    k5_arcfour_docrypt,
+    k5_arcfour_docrypt,
+    k5_arcfour_make_key,
+    k5_arcfour_init_state, /*xxx not implemented yet*/
+    krb5int_default_free_state,
+    k5_arcfour_docrypt_iov,
+    k5_arcfour_docrypt_iov
+};
+