ressurect files missed by merge

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@11006 dc483132-0cff-0310-8789-dd5450dbe970

7 files changed, 738 insertions, 0 deletions

diff --git a/src/lib/crypto/dk/Makefile.in b/src/lib/crypto/dk/Makefile.in
new file mode 100644
index 0000000000..076b0dd66e
--- /dev/null
+++ b/src/lib/crypto/dk/Makefile.in
@@ -0,0 +1,44 @@
+thisconfigdir=./..
+BUILDTOP=$(REL)$(U)$(S)$(U)$(S)$(U)
+CFLAGS = $(CCOPTS) $(DEFS) -I$(srcdir)/..
+
+##DOS##BUILDTOP = ..\..\..
+##DOS##PREFIXDIR=dk
+##DOS##OBJFILE=..\dk.lst
+##WIN16##LIBNAME=..\crypto.lib
+
+PROG_LIBPATH=-L$(TOPLIBD)
+PROG_RPATH=$(KRB5_LIBDIR)
+
+RUN_SETUP = @KRB5_RUN_ENV@ KRB5_CONFIG=$(SRCTOP)/config-files/krb5.conf
+
+STLIBOBJS=\
+	checksum.o	\
+	decrypt.o	\
+	derive.o	\
+	encrypt.o	\
+	stringtokey.o
+
+OBJS=\
+	checksum.$(OBJEXT)	\
+	decrypt.$(OBJEXT)	\
+	derive.$(OBJEXT)	\
+	encrypt.$(OBJEXT)	\
+	stringtokey.$(OBJEXT)
+
+SRCS=\
+	$(srcdir)/checksum.c	\
+	$(srcdir)/decrypt.c	\
+	$(srcdir)/derive.c	\
+	$(srcdir)/encrypt.c	\
+	$(srcdir)/stringtokey.c
+
+##DOS##LIBOBJS = $(OBJS)
+
+all-unix:: all-libobjs
+
+includes:: depend
+
+depend:: $(SRCS)
+
+clean-unix:: clean-libobjs
diff --git a/src/lib/crypto/dk/checksum.c b/src/lib/crypto/dk/checksum.c
new file mode 100644
index 0000000000..db64e6cb65
--- /dev/null
+++ b/src/lib/crypto/dk/checksum.c
@@ -0,0 +1,104 @@
+/*
+ * 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 "etypes.h"
+#include "dk.h"
+
+#define K5CLENGTH 5 /* 32 bit net byte order integer + one byte seed */
+
+krb5_error_code
+krb5_dk_make_checksum(hash, key, usage, input, output)
+     krb5_const struct krb5_hash_provider *hash;
+     krb5_const krb5_keyblock *key;
+     krb5_keyusage usage;
+     krb5_const krb5_data *input;
+     krb5_data *output;
+{
+    int i;
+    struct krb5_enc_provider *enc;
+    size_t blocksize, keybytes, keylength;
+    krb5_error_code ret;
+    unsigned char constantdata[K5CLENGTH];
+    krb5_data datain;
+    unsigned char *kcdata;
+    krb5_keyblock kc;
+
+    for (i=0; i<krb5_enctypes_length; i++) {
+	if (krb5_enctypes_list[i].etype == key->enctype)
+	    break;
+    }
+
+    if (i == krb5_enctypes_length)
+	return(KRB5_BAD_ENCTYPE);
+
+    enc = krb5_enctypes_list[i].enc;
+
+    /* allocate and set to-be-derived keys */
+
+    (*(enc->block_size))(&blocksize);
+    (*(enc->keysize))(&keybytes, &keylength);
+
+    /* key->length will be tested in enc->encrypt
+       output->length will be tested in krb5_hmac */
+
+    if ((kcdata = (unsigned char *) malloc(keylength)) == NULL)
+	return(ENOMEM);
+
+    kc.contents = kcdata;
+    kc.length = keylength;
+
+    /* derive the key */
+ 
+    datain.data = constantdata;
+    datain.length = K5CLENGTH;
+
+    datain.data[0] = (usage>>24)&0xff;
+    datain.data[1] = (usage>>16)&0xff;
+    datain.data[2] = (usage>>8)&0xff;
+    datain.data[3] = usage&0xff;
+
+    datain.data[4] = 0x99;
+
+    if (ret = krb5_derive_key(enc, key, &kc, &datain))
+	goto cleanup;
+
+    /* hash the data */
+
+    datain = *input;
+
+    if (ret = krb5_hmac(hash, &kc, 1, &datain, output))
+	memset(output->data, 0, output->length);
+
+    /* ret is set correctly by the prior call */
+
+cleanup:
+    memset(kcdata, 0, keylength);
+
+    free(kcdata);
+
+    return(ret);
+}
diff --git a/src/lib/crypto/dk/decrypt.c b/src/lib/crypto/dk/decrypt.c
new file mode 100644
index 0000000000..9fedffbc09
--- /dev/null
+++ b/src/lib/crypto/dk/decrypt.c
@@ -0,0 +1,151 @@
+/*
+ * 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 "dk.h"
+
+#define K5CLENGTH 5 /* 32 bit net byte order integer + one byte seed */
+
+krb5_error_code
+krb5_dk_decrypt(enc, hash, key, usage, ivec, input, output)
+     krb5_const struct krb5_enc_provider *enc;
+     krb5_const struct krb5_hash_provider *hash;
+     krb5_const krb5_keyblock *key;
+     krb5_keyusage usage;
+     krb5_const krb5_data *ivec;
+     krb5_const krb5_data *input;
+     krb5_data *output;
+{
+    krb5_error_code ret;
+    size_t hashsize, blocksize, keybytes, keylength, enclen, plainlen;
+    unsigned char *plaindata, *kedata, *kidata, *cksum;
+    krb5_keyblock ke, ki;
+    krb5_data d1, d2;
+    unsigned char constantdata[K5CLENGTH];
+
+    /* allocate and set up ciphertext and to-be-derived keys */
+
+    (*(hash->hash_size))(&hashsize);
+    (*(enc->block_size))(&blocksize);
+    (*(enc->keysize))(&keybytes, &keylength);
+
+    enclen = input->length - hashsize;
+
+    if ((kedata = (unsigned char *) malloc(keylength)) == NULL)
+	return(ENOMEM);
+    if ((kidata = (unsigned char *) malloc(keylength)) == NULL) {
+	free(kedata);
+	return(ENOMEM);
+    }
+    if ((plaindata = (unsigned char *) malloc(enclen)) == NULL) {
+	free(kidata);
+	free(kedata);
+	return(ENOMEM);
+    }
+    if ((cksum = (unsigned char *) malloc(hashsize)) == NULL) {
+	free(plaindata);
+	free(kidata);
+	free(kedata);
+	return(ENOMEM);
+    }
+
+    ke.contents = kedata;
+    ke.length = keylength;
+    ki.contents = kidata;
+    ki.length = keylength;
+
+    /* derive the keys */
+
+    d1.data = constantdata;
+    d1.length = K5CLENGTH;
+
+    d1.data[0] = (usage>>24)&0xff;
+    d1.data[1] = (usage>>16)&0xff;
+    d1.data[2] = (usage>>8)&0xff;
+    d1.data[3] = usage&0xff;
+
+    d1.data[4] = 0xAA;
+
+    if (ret = krb5_derive_key(enc, key, &ke, &d1))
+	goto cleanup;
+
+    d1.data[4] = 0x55;
+
+    if (ret = krb5_derive_key(enc, key, &ki, &d1))
+	goto cleanup;
+
+    /* decrypt the ciphertext */
+
+    d1.length = enclen;
+    d1.data = input->data;
+
+    d2.length = enclen;
+    d2.data = plaindata;
+
+    if (ret = ((*(enc->decrypt))(&ke, ivec, &d1, &d2)))
+	goto cleanup;
+
+    /* verify the hash */
+
+    d1.length = hashsize;
+    d1.data = cksum;
+
+    if (ret = krb5_hmac(hash, &ki, 1, &d2, &d1))
+	goto cleanup;
+
+    if (memcmp(cksum, input->data+enclen, hashsize) != 0) {
+	ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
+	goto cleanup;
+    }
+
+    /* because this encoding isn't self-describing wrt length, the
+       best we can do here is to compute the length minus the
+       confounder. */
+
+    plainlen = enclen - blocksize;
+
+    if (output->length < plainlen)
+	return(KRB5_BAD_MSIZE);
+
+    output->length = plainlen;
+
+    memcpy(output->data, d2.data+blocksize, output->length);
+
+    ret = 0;
+
+cleanup:
+    memset(kedata, 0, keylength);
+    memset(kidata, 0, keylength);
+    memset(plaindata, 0, enclen);
+    memset(cksum, 0, hashsize);
+
+    free(cksum);
+    free(plaindata);
+    free(kidata);
+    free(kedata);
+
+    return(ret);
+}
diff --git a/src/lib/crypto/dk/derive.c b/src/lib/crypto/dk/derive.c
new file mode 100644
index 0000000000..8765605fbc
--- /dev/null
+++ b/src/lib/crypto/dk/derive.c
@@ -0,0 +1,114 @@
+/*
+ * 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 "dk.h"
+
+krb5_error_code
+krb5_derive_key(enc, inkey, outkey, in_constant)
+     krb5_const struct krb5_enc_provider *enc;
+     krb5_const krb5_keyblock *inkey;
+     krb5_keyblock *outkey;
+     krb5_const krb5_data *in_constant;
+{
+    size_t blocksize, keybytes, keylength, n;
+    unsigned char *inblockdata, *outblockdata, *rawkey;
+    krb5_data inblock, outblock;
+
+    (*(enc->block_size))(&blocksize);
+    (*(enc->keysize))(&keybytes, &keylength);
+
+    if ((inkey->length != keylength) ||
+	(outkey->length != keylength))
+	return(KRB5_CRYPTO_INTERNAL);
+
+    /* allocate and set up buffers */
+
+    if ((inblockdata = (unsigned char *) malloc(blocksize)) == NULL)
+	return(ENOMEM);
+
+    if ((outblockdata = (unsigned char *) malloc(blocksize)) == NULL) {
+	return(ENOMEM);
+	free(inblockdata);
+    }
+
+    if ((rawkey = (unsigned char *) malloc(keybytes)) == NULL) {
+	return(ENOMEM);
+	free(outblockdata);
+	free(inblockdata);
+    }
+
+    inblock.data = inblockdata;
+    inblock.length = blocksize;
+
+    outblock.data = outblockdata;
+    outblock.length = blocksize;
+
+    /* initialize the input block */
+
+    if (in_constant->length == inblock.length) {
+	memcpy(inblock.data, in_constant->data, inblock.length);
+    } else {
+	krb5_nfold(in_constant->length*8, in_constant->data,
+		   inblock.length*8, inblock.data);
+    }
+
+    /* loop encrypting the blocks until enough key bytes are generated */
+
+    n = 0;
+    while (n < keybytes) {
+	(*(enc->encrypt))(inkey, 0, &inblock, &outblock);
+
+	if ((keybytes - n) <= outblock.length) {
+	    memcpy(rawkey+n, outblock.data, (keybytes - n));
+	    break;
+	}
+
+	memcpy(rawkey+n, outblock.data, outblock.length);
+	memcpy(inblock.data, outblock.data, outblock.length);
+	n += outblock.length;
+    }
+
+    /* postprocess the key */
+
+    inblock.data = rawkey;
+    inblock.length = keybytes;
+
+    (*(enc->make_key))(&inblock, outkey);
+
+    /* clean memory, free resources and exit */
+
+    memset(inblockdata, 0, blocksize);
+    memset(outblockdata, 0, blocksize);
+    memset(rawkey, 0, keybytes);
+
+    free(rawkey);
+    free(outblockdata);
+    free(inblockdata);
+
+    return(0);
+}
+
diff --git a/src/lib/crypto/dk/dk.h b/src/lib/crypto/dk/dk.h
new file mode 100644
index 0000000000..e4acddabc0
--- /dev/null
+++ b/src/lib/crypto/dk/dk.h
@@ -0,0 +1,61 @@
+/*
+ * 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"
+
+void krb5_dk_encrypt_length
+KRB5_PROTOTYPE((krb5_const struct krb5_enc_provider *enc,
+		krb5_const struct krb5_hash_provider *hash,
+		size_t input, size_t *length));
+
+krb5_error_code krb5_dk_encrypt
+KRB5_PROTOTYPE((krb5_const struct krb5_enc_provider *enc,
+		krb5_const struct krb5_hash_provider *hash,
+		krb5_const krb5_keyblock *key, krb5_keyusage usage,
+		krb5_const krb5_data *ivec,
+		krb5_const krb5_data *input, krb5_data *output));
+
+krb5_error_code krb5_dk_decrypt
+KRB5_PROTOTYPE((krb5_const struct krb5_enc_provider *enc,
+		krb5_const struct krb5_hash_provider *hash,
+		krb5_const krb5_keyblock *key, krb5_keyusage usage,
+		krb5_const krb5_data *ivec, krb5_const krb5_data *input,
+		krb5_data *arg_output));
+
+krb5_error_code krb5_dk_string_to_key
+KRB5_PROTOTYPE((krb5_const struct krb5_enc_provider *enc, 
+		krb5_const krb5_data *string, krb5_const krb5_data *salt,
+		krb5_keyblock *key));
+
+krb5_error_code krb5_derive_key
+KRB5_PROTOTYPE((krb5_const struct krb5_enc_provider *enc,
+		krb5_const krb5_keyblock *inkey,
+		krb5_keyblock *outkey, krb5_const krb5_data *in_constant));
+
+krb5_error_code krb5_dk_make_checksum
+KRB5_PROTOTYPE((krb5_const struct krb5_hash_provider *hash,
+		krb5_const krb5_keyblock *key, krb5_keyusage usage,
+		krb5_const krb5_data *input, krb5_data *output));
diff --git a/src/lib/crypto/dk/encrypt.c b/src/lib/crypto/dk/encrypt.c
new file mode 100644
index 0000000000..4a3a00b300
--- /dev/null
+++ b/src/lib/crypto/dk/encrypt.c
@@ -0,0 +1,167 @@
+/*
+ * 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 "dk.h"
+
+#define K5CLENGTH 5 /* 32 bit net byte order integer + one byte seed */
+
+/* the spec says that the confounder size and padding are specific to
+   the encryption algorithm.  This code (dk_encrypt_length and
+   dk_encrypt) assume the confounder is always the blocksize, and the
+   padding is always zero bytes up to the blocksize.  If these
+   assumptions ever fails, the keytype table should be extended to
+   include these bits of info. */
+
+void
+krb5_dk_encrypt_length(enc, hash, inputlen, length)
+     krb5_const struct krb5_enc_provider *enc;
+     krb5_const struct krb5_hash_provider *hash;
+     size_t inputlen;
+     size_t *length;
+{
+    size_t blocksize, hashsize;
+
+    (*(enc->block_size))(&blocksize);
+    (*(hash->hash_size))(&hashsize);
+
+    *length = krb5_roundup(blocksize+inputlen, blocksize) + hashsize;
+}
+
+krb5_error_code
+krb5_dk_encrypt(enc, hash, key, usage, ivec, input, output)
+     krb5_const struct krb5_enc_provider *enc;
+     krb5_const struct krb5_hash_provider *hash;
+     krb5_const krb5_keyblock *key;
+     krb5_keyusage usage;
+     krb5_const krb5_data *ivec;
+     krb5_const krb5_data *input;
+     krb5_data *output;
+{
+    size_t blocksize, keybytes, keylength, plainlen, enclen;
+    krb5_error_code ret;
+    unsigned char constantdata[K5CLENGTH];
+    krb5_data d1, d2;
+    unsigned char *plaintext, *kedata, *kidata;
+    krb5_keyblock ke, ki;
+
+    /* allocate and set up plaintext and to-be-derived keys */
+
+    (*(enc->block_size))(&blocksize);
+    (*(enc->keysize))(&keybytes, &keylength);
+    plainlen = krb5_roundup(blocksize+input->length, blocksize);
+
+    krb5_dk_encrypt_length(enc, hash, input->length, &enclen);
+
+    /* key->length, ivec will be tested in enc->encrypt */
+
+    if (output->length < enclen)
+	return(KRB5_BAD_MSIZE);
+
+    if ((kedata = (unsigned char *) malloc(keylength)) == NULL)
+	return(ENOMEM);
+    if ((kidata = (unsigned char *) malloc(keylength)) == NULL) {
+	free(kedata);
+	return(ENOMEM);
+    }
+    if ((plaintext = (unsigned char *) malloc(plainlen)) == NULL) {
+	free(kidata);
+	free(kedata);
+	return(ENOMEM);
+    }
+
+    ke.contents = kedata;
+    ke.length = keylength;
+    ki.contents = kidata;
+    ki.length = keylength;
+
+    /* derive the keys */
+
+    d1.data = constantdata;
+    d1.length = K5CLENGTH;
+
+    d1.data[0] = (usage>>24)&0xff;
+    d1.data[1] = (usage>>16)&0xff;
+    d1.data[2] = (usage>>8)&0xff;
+    d1.data[3] = usage&0xff;
+
+    d1.data[4] = 0xAA;
+
+    if (ret = krb5_derive_key(enc, key, &ke, &d1))
+	goto cleanup;
+
+    d1.data[4] = 0x55;
+
+    if (ret = krb5_derive_key(enc, key, &ki, &d1))
+	goto cleanup;
+
+    /* put together the plaintext */
+
+    d1.length = blocksize;
+    d1.data = plaintext;
+
+    if (ret = krb5_c_random_make_octets(/* XXX */ 0, &d1))
+	goto cleanup;
+
+    memcpy(plaintext+blocksize, input->data, input->length);
+
+    memset(plaintext+blocksize+input->length, 0,
+	   plainlen - (blocksize+input->length));
+
+    /* encrypt the plaintext */
+
+    d1.length = plainlen;
+    d1.data = plaintext;
+
+    d2.length = plainlen;
+    d2.data = output->data;
+
+    if (ret = ((*(enc->encrypt))(&ke, ivec, &d1, &d2)))
+	goto cleanup;
+
+    /* hash the plaintext */
+
+    d2.length = enclen - plainlen;
+    d2.data = output->data+plainlen;
+
+    output->length = enclen;
+
+    if (ret = krb5_hmac(hash, &ki, 1, &d1, &d2))
+	memset(d2.data, 0, d2.length);
+
+    /* ret is set correctly by the prior call */
+
+cleanup:
+    memset(kedata, 0, keylength);
+    memset(kidata, 0, keylength);
+    memset(plaintext, 0, plainlen);
+
+    free(plaintext);
+    free(kidata);
+    free(kedata);
+
+    return(ret);
+}
diff --git a/src/lib/crypto/dk/stringtokey.c b/src/lib/crypto/dk/stringtokey.c
new file mode 100644
index 0000000000..c033dc35a7
--- /dev/null
+++ b/src/lib/crypto/dk/stringtokey.c
@@ -0,0 +1,97 @@
+/*
+ * 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"
+
+static unsigned char kerberos[] = "kerberos";
+#define kerberos_len (sizeof(kerberos)-1)
+
+krb5_error_code
+krb5_dk_string_to_key(enc, string, salt, key)
+     krb5_const struct krb5_enc_provider *enc;
+     krb5_const krb5_data *string;
+     krb5_const krb5_data *salt;
+     krb5_keyblock *key;
+{
+    krb5_error_code ret;
+    size_t keybytes, keylength, concatlen;
+    unsigned char *concat, *foldstring, *foldkeydata;
+    krb5_data indata;
+    krb5_keyblock foldkey;
+
+    /* key->length is checked by krb5_derive_key */
+
+    (*(enc->keysize))(&keybytes, &keylength);
+
+    concatlen = string->length+(salt?salt->length:0);
+
+    if ((concat = (unsigned char *) malloc(concatlen)) == NULL)
+	return(ENOMEM);
+    if ((foldstring = (unsigned char *) malloc(keybytes)) == NULL) {
+	free(concat);
+	return(ENOMEM);
+    }
+    if ((foldkeydata = (unsigned char *) malloc(keylength)) == NULL) {
+	free(foldstring);
+	free(concat);
+	return(ENOMEM);
+    }
+
+    /* construct input string ( = string + salt), fold it, make_key it */
+
+    memcpy(concat, string->data, string->length);
+    if (salt)
+	memcpy(concat+string->length, salt->data, salt->length);
+
+    krb5_nfold(concatlen*8, concat, keybytes*8, foldstring);
+
+    indata.length = keybytes;
+    indata.data = foldstring;
+    foldkey.length = keylength;
+    foldkey.contents = foldkeydata;
+
+    (*(enc->make_key))(&indata, &foldkey);
+
+    /* now derive the key from this one */
+
+    indata.length = kerberos_len;
+    indata.data = kerberos;
+
+    if (ret = krb5_derive_key(enc, &foldkey, key, &indata))
+	memset(key->contents, 0, key->length);
+
+    /* ret is set correctly by the prior call */
+
+    memset(concat, 0, concatlen);
+    memset(foldstring, 0, keybytes);
+    memset(foldkeydata, 0, keylength);
+
+    free(foldkeydata);
+    free(foldstring);
+    free(concat);
+
+    return(ret);
+}