In light of the recent 2^69 operation collision-finding attack on SHA1,

add support for SHA256.

Tested on:	i386, sparc64
Tested using:	NIST test vectors, built-in tests
X-MFC-after:	5.4-RELEASE

5 files changed, 522 insertions, 6 deletions

diff --git a/lib/libmd/Makefile b/lib/libmd/Makefile
index f3759eb..a98b409 100644
--- a/lib/libmd/Makefile
+++ b/lib/libmd/Makefile
@@ -4,10 +4,11 @@ LIB=	md
 SHLIBDIR?= /lib
 SRCS=	md2c.c md4c.c md5c.c md2hl.c md4hl.c md5hl.c \
 	rmd160c.c rmd160hl.c \
-	sha0c.c sha0hl.c sha1c.c sha1hl.c
-INCS=	md2.h md4.h md5.h ripemd.h sha.h
+	sha0c.c sha0hl.c sha1c.c sha1hl.c \
+	sha256c.c sha256hl.c
+INCS=	md2.h md4.h md5.h ripemd.h sha.h sha256.h
 
-MAN+=	md2.3 md4.3 md5.3 ripemd.3 sha.3
+MAN+=	md2.3 md4.3 md5.3 ripemd.3 sha.3 sha256.3
 MLINKS+=md2.3 MD2Init.3 md2.3 MD2Update.3 md2.3 MD2Final.3
 MLINKS+=md2.3 MD2End.3  md2.3 MD2File.3   md2.3 MD2FileChunk.3
 MLINKS+=md2.3 MD2Data.3
@@ -27,9 +28,14 @@ MLINKS+=sha.3 SHA_Data.3
 MLINKS+=sha.3 SHA1_Init.3 sha.3 SHA1_Update.3 sha.3 SHA1_Final.3
 MLINKS+=sha.3 SHA1_End.3  sha.3 SHA1_File.3   sha.3 SHA1_FileChunk.3
 MLINKS+=sha.3 SHA1_Data.3
+MLINKS+=sha256.3 SHA256_Init.3  sha256.3 SHA256_Update.3
+MLINKS+=sha256.3 SHA256_Final.3 sha256.3 SHA256_End.3
+MLINKS+=sha256.3 SHA256_File.3  sha256.3 SHA256_FileChunk.3
+MLINKS+=sha256.3 SHA256_Data.3
 CLEANFILES+=	md[245]hl.c md[245].ref md[245].3 mddriver \
 		rmd160.ref rmd160hl.c rmddriver \
-		sha0.ref sha0hl.c sha1.ref sha1hl.c shadriver
+		sha0.ref sha0hl.c sha1.ref sha1hl.c shadriver \
+		sha256.ref sha256hl.c
 CFLAGS+= -I${.CURDIR}
 .PATH: ${.CURDIR}/${MACHINE_ARCH}
 
@@ -64,6 +70,12 @@ sha1hl.c: mdXhl.c
 		sed -e 's/mdX/sha/g' -e 's/MDX/SHA1_/g' -e 's/SHA1__/SHA1_/g' \
 		${.ALLSRC}) > ${.TARGET}
 
+sha256hl.c: mdXhl.c
+	(echo '#define LENGTH 32'; \
+		sed -e 's/mdX/sha256/g' -e 's/MDX/SHA256_/g'	\
+			-e  's/SHA256__/SHA256_/g' \
+		${.ALLSRC}) > ${.TARGET}
+
 rmd160hl.c: mdXhl.c
 	(echo '#define LENGTH 20'; \
 		sed -e 's/mdX/ripemd/g' -e 's/MDX/RIPEMD160_/g' \
@@ -132,6 +144,15 @@ sha1.ref:
 	echo 'SHA-1 ("12345678901234567890123456789012345678901234567890123456789012345678901234567890") =' \
 		'50abf5706a150990a08b2c5ea40fa0e585554732' ) > ${.TARGET}
 
+sha256.ref:
+	echo 'SHA-256 test suite:' > ${.TARGET}
+	@echo 'SHA-256 ("") = e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855' >> ${.TARGET}
+	@echo 'SHA-256 ("abc") = ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad' >> ${.TARGET}
+	@echo 'SHA-256 ("message digest") = f7846f55cf23e14eebeab5b4e1550cad5b509e3348fbc4efa3a1413d393cb650' >> ${.TARGET}
+	@echo 'SHA-256 ("abcdefghijklmnopqrstuvwxyz") = 71c480df93d6ae2f1efad1447c66c9525e316218cf51fc8d9ed832f2daf18b73' >> ${.TARGET}
+	@echo 'SHA-256 ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") = db4bfcbd4da0cd85a60c3c37d3fbd8805c77f15fc6b1fdfe614ee0a7c8fdb4c0' >> ${.TARGET}
+	@echo 'SHA-256 ("12345678901234567890123456789012345678901234567890123456789012345678901234567890") = f371bc4a311f2b009eef952dd83ca80e2b60026c8e935592d0f9c308453c813e' >> ${.TARGET}
+
 rmd160.ref:
 	(echo 'RIPEMD160 test suite:'; \
 	echo 'RIPEMD160 ("") = 9c1185a5c5e9fc54612808977ee8f548b2258d31'; \
@@ -145,7 +166,7 @@ rmd160.ref:
 	echo 'RIPEMD160 ("12345678901234567890123456789012345678901234567890123456789012345678901234567890") =' \
 		'9b752e45573d4b39f4dbd3323cab82bf63326bfb' ) > ${.TARGET}
 
-test:	md2.ref md4.ref md5.ref sha0.ref rmd160.ref sha1.ref
+test:	md2.ref md4.ref md5.ref sha0.ref rmd160.ref sha1.ref sha256.ref
 	@${ECHO} if any of these test fail, the code produces wrong results
 	@${ECHO} and should NOT be used.
 	${CC} ${CFLAGS} ${LDFLAGS} -DMD=2 -o mddriver ${.CURDIR}/mddriver.c -L. -lmd
@@ -168,6 +189,9 @@ test:	md2.ref md4.ref md5.ref sha0.ref rmd160.ref sha1.ref
 	${CC} ${CFLAGS} ${LDFLAGS} -DSHA=1 -o shadriver ${.CURDIR}/shadriver.c -L. -lmd
 	./shadriver | cmp sha1.ref -
 	@${ECHO} SHA-1 passed test
+	${CC} ${CFLAGS} ${LDFLAGS} -DSHA=256 -o shadriver ${.CURDIR}/shadriver.c -L. -lmd
+	./shadriver | cmp sha256.ref -
+	@${ECHO} SHA-256 passed test
 	-rm -f shadriver
 
 .include <bsd.lib.mk>
diff --git a/lib/libmd/sha256.3 b/lib/libmd/sha256.3
new file mode 100644
index 0000000..f6de8c7
--- /dev/null
+++ b/lib/libmd/sha256.3
@@ -0,0 +1,140 @@
+.\"
+.\" ----------------------------------------------------------------------------
+.\" "THE BEER-WARE LICENSE" (Revision 42):
+.\" <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
+.\" can do whatever you want with this stuff. If we meet some day, and you think
+.\" this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+.\" ----------------------------------------------------------------------------
+.\"
+.\" 	From: Id: mdX.3,v 1.14 1999/02/11 20:31:49 wollman Exp
+.\" $FreeBSD$
+.\"
+.Dd March 9, 2005
+.Dt SHA256 3
+.Os
+.Sh NAME
+.Nm SHA256_Init ,
+.Nm SHA256_Update ,
+.Nm SHA256_Final ,
+.Nm SHA256_End ,
+.Nm SHA256_File ,
+.Nm SHA256_FileChunk ,
+.Nm SHA256_Data
+.Nd calculate the FIPS 180-2 ``SHA-256'' message digest
+.Sh LIBRARY
+.Lb libmd
+.Sh SYNOPSIS
+.In sys/types.h
+.In sha256.h
+.Ft void
+.Fn SHA256_Init "SHA_CTX *context"
+.Ft void
+.Fn SHA256_Update "SHA_CTX *context" "const unsigned char *data" "size_t len"
+.Ft void
+.Fn SHA256_Final "unsigned char digest[32]" "SHA_CTX *context"
+.Ft "char *"
+.Fn SHA256_End "SHA_CTX *context" "char *buf"
+.Ft "char *"
+.Fn SHA256_File "const char *filename" "char *buf"
+.Ft "char *"
+.Fn SHA256_FileChunk "const char *filename" "char *buf" "off_t offset" "off_t length"
+.Ft "char *"
+.Fn SHA256_Data "const unsigned char *data" "unsigned int len" "char *buf"
+.Sh DESCRIPTION
+The
+.Li SHA256_
+functions calculate a 256-bit cryptographic checksum (digest)
+for any number of input bytes.
+A cryptographic checksum is a one-way
+hash function; that is, it is computationally impractical to find
+the input corresponding to a particular output.
+This net result is
+a
+.Dq fingerprint
+of the input-data, which does not disclose the actual input.
+.Pp
+The
+.Fn SHA256_Init ,
+.Fn SHA256_Update ,
+and
+.Fn SHA256_Final
+functions are the core functions.
+Allocate an
+.Vt SHA256_CTX ,
+initialize it with
+.Fn SHA256_Init ,
+run over the data with
+.Fn SHA256_Update ,
+and finally extract the result using
+.Fn SHA256_Final .
+.Pp
+.Fn SHA256_End
+is a wrapper for
+.Fn SHA256_Final
+which converts the return value to a 65-character
+(including the terminating '\e0')
+.Tn ASCII
+string which represents the 256 bits in hexadecimal.
+.Pp
+.Fn SHA256_File
+calculates the digest of a file, and uses
+.Fn SHA256_End
+to return the result.
+If the file cannot be opened, a null pointer is returned.
+.Fn SHA256_FileChunk
+is similar to
+.Fn SHA256_File ,
+but it only calculates the digest over a byte-range of the file specified,
+starting at
+.Fa offset
+and spanning
+.Fa length
+bytes.
+If the
+.Fa length
+parameter is specified as 0, or more than the length of the remaining part
+of the file,
+.Fn SHA256_FileChunk
+calculates the digest from
+.Fa offset
+to the end of file.
+.Fn SHA256_Data
+calculates the digest of a chunk of data in memory, and uses
+.Fn SHA256_End
+to return the result.
+.Pp
+When using
+.Fn SHA256_End ,
+.Fn SHA256_File ,
+or
+.Fn SHA256_Data ,
+the
+.Fa buf
+argument can be a null pointer, in which case the returned string
+is allocated with
+.Xr malloc 3
+and subsequently must be explicitly deallocated using
+.Xr free 3
+after use.
+If the
+.Fa buf
+argument is non-null it must point to at least 65 characters of buffer space.
+.Sh SEE ALSO
+.Xr md2 3 ,
+.Xr md4 3 ,
+.Xr md5 3 ,
+.Xr ripemd 3 ,
+.Xr sha 3
+.Sh HISTORY
+These functions appeared in
+.Fx 4.0 .
+.Sh AUTHORS
+The core hash routines were implemented by Colin Percival based on
+the published
+.Tn FIPS 180-2
+standard.
+.Sh BUGS
+No method is known to exist which finds two files having the same hash value,
+nor to find a file with a specific hash value.
+There is on the other hand no guarantee that such a method does not exist.
+
diff --git a/lib/libmd/sha256.h b/lib/libmd/sha256.h
new file mode 100644
index 0000000..de4cd43
--- /dev/null
+++ b/lib/libmd/sha256.h
@@ -0,0 +1,50 @@
+/*-
+ * Copyright 2005 Colin Percival
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _SHA256_H_
+#define _SHA256_H_
+
+#include <sys/types.h>
+
+typedef struct SHA256Context {
+	uint32_t state[8];
+	uint32_t count[2];
+	unsigned char buf[64];
+} SHA256_CTX;
+
+__BEGIN_DECLS
+void	SHA256_Init(SHA256_CTX *);
+void	SHA256_Update(SHA256_CTX *, const unsigned char *, size_t);
+void	SHA256_Final(unsigned char [32], SHA256_CTX *);
+char   *SHA256_End(SHA256_CTX *, char *);
+char   *SHA256_File(const char *, char *);
+char   *SHA256_FileChunk(const char *, char *, off_t, off_t);
+char   *SHA256_Data(const unsigned char *, unsigned int, char *);
+__END_DECLS
+
+#endif /* !_SHA256_H_ */
diff --git a/lib/libmd/sha256c.c b/lib/libmd/sha256c.c
new file mode 100644
index 0000000..d94e871
--- /dev/null
+++ b/lib/libmd/sha256c.c
@@ -0,0 +1,299 @@
+/*-
+ * Copyright 2005 Colin Percival
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/endian.h>
+#include <sys/types.h>
+
+#include <string.h>
+
+#include "sha256.h"
+
+#if BYTE_ORDER == BIG_ENDIAN
+
+/* Copy a vector of big-endian uint32_t into a vector of bytes */
+#define be32enc_vect(dst, src, len)	\
+	memcpy((void *)dst, (const void *)src, (size_t)len)
+
+/* Copy a vector of bytes into a vector of big-endian uint32_t */
+#define be32dec_vect(dst, src, len)	\
+	memcpy((void *)dst, (const void *)src, (size_t)len)
+
+#else /* BYTE_ORDER != BIG_ENDIAN */
+
+/*
+ * Encode a length len/4 vector of (uint32_t) into a length len vector of
+ * (unsigned char) in big-endian form.  Assumes len is a multiple of 4.
+ */
+static void
+be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len)
+{
+	size_t i;
+
+	for (i = 0; i < len / 4; i++)
+		be32enc(dst + i * 4, src[i]);
+}
+
+/*
+ * Decode a big-endian length len vector of (unsigned char) into a length
+ * len/4 vector of (uint32_t).  Assumes len is a multiple of 4.
+ */
+static void
+be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len)
+{
+	size_t i;
+
+	for (i = 0; i < len / 4; i++)
+		dst[i] = be32dec(src + i * 4);
+}
+
+#endif /* BYTE_ORDER != BIG_ENDIAN */
+
+/* Elementary functions used by SHA256 */
+#define Ch(x, y, z)	((x & (y ^ z)) ^ z)
+#define Maj(x, y, z)	((x & (y | z)) | (y & z))
+#define SHR(x, n)	(x >> n)
+#define ROTR(x, n)	((x >> n) | (x << (32 - n)))
+#define S0(x)		(ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
+#define S1(x)		(ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
+#define s0(x)		(ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
+#define s1(x)		(ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
+
+/* SHA256 round function */
+#define RND(a, b, c, d, e, f, g, h, k)			\
+	t0 = h + S1(e) + Ch(e, f, g) + k;		\
+	t1 = S0(a) + Maj(a, b, c);			\
+	d += t0;					\
+	h  = t0 + t1;
+
+/* Adjusted round function for rotating state */
+#define RNDr(S, W, i, k)			\
+	RND(S[(64 - i) % 8], S[(65 - i) % 8],	\
+	    S[(66 - i) % 8], S[(67 - i) % 8],	\
+	    S[(68 - i) % 8], S[(69 - i) % 8],	\
+	    S[(70 - i) % 8], S[(71 - i) % 8],	\
+	    W[i] + k)
+
+/*
+ * SHA256 block compression function.  The 256-bit state is transformed via
+ * the 512-bit input block to produce a new state.
+ */
+static void
+SHA256_Transform(uint32_t * state, const unsigned char block[64])
+{
+	uint32_t W[64];
+	uint32_t S[8];
+	uint32_t t0, t1;
+	int i;
+
+	/* 1. Prepare message schedule W. */
+	be32dec_vect(W, block, 64);
+	for (i = 16; i < 64; i++)
+		W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16];
+
+	/* 2. Initialize working variables. */
+	memcpy(S, state, 32);
+
+	/* 3. Mix. */
+	RNDr(S, W, 0, 0x428a2f98);
+	RNDr(S, W, 1, 0x71374491);
+	RNDr(S, W, 2, 0xb5c0fbcf);
+	RNDr(S, W, 3, 0xe9b5dba5);
+	RNDr(S, W, 4, 0x3956c25b);
+	RNDr(S, W, 5, 0x59f111f1);
+	RNDr(S, W, 6, 0x923f82a4);
+	RNDr(S, W, 7, 0xab1c5ed5);
+	RNDr(S, W, 8, 0xd807aa98);
+	RNDr(S, W, 9, 0x12835b01);
+	RNDr(S, W, 10, 0x243185be);
+	RNDr(S, W, 11, 0x550c7dc3);
+	RNDr(S, W, 12, 0x72be5d74);
+	RNDr(S, W, 13, 0x80deb1fe);
+	RNDr(S, W, 14, 0x9bdc06a7);
+	RNDr(S, W, 15, 0xc19bf174);
+	RNDr(S, W, 16, 0xe49b69c1);
+	RNDr(S, W, 17, 0xefbe4786);
+	RNDr(S, W, 18, 0x0fc19dc6);
+	RNDr(S, W, 19, 0x240ca1cc);
+	RNDr(S, W, 20, 0x2de92c6f);
+	RNDr(S, W, 21, 0x4a7484aa);
+	RNDr(S, W, 22, 0x5cb0a9dc);
+	RNDr(S, W, 23, 0x76f988da);
+	RNDr(S, W, 24, 0x983e5152);
+	RNDr(S, W, 25, 0xa831c66d);
+	RNDr(S, W, 26, 0xb00327c8);
+	RNDr(S, W, 27, 0xbf597fc7);
+	RNDr(S, W, 28, 0xc6e00bf3);
+	RNDr(S, W, 29, 0xd5a79147);
+	RNDr(S, W, 30, 0x06ca6351);
+	RNDr(S, W, 31, 0x14292967);
+	RNDr(S, W, 32, 0x27b70a85);
+	RNDr(S, W, 33, 0x2e1b2138);
+	RNDr(S, W, 34, 0x4d2c6dfc);
+	RNDr(S, W, 35, 0x53380d13);
+	RNDr(S, W, 36, 0x650a7354);
+	RNDr(S, W, 37, 0x766a0abb);
+	RNDr(S, W, 38, 0x81c2c92e);
+	RNDr(S, W, 39, 0x92722c85);
+	RNDr(S, W, 40, 0xa2bfe8a1);
+	RNDr(S, W, 41, 0xa81a664b);
+	RNDr(S, W, 42, 0xc24b8b70);
+	RNDr(S, W, 43, 0xc76c51a3);
+	RNDr(S, W, 44, 0xd192e819);
+	RNDr(S, W, 45, 0xd6990624);
+	RNDr(S, W, 46, 0xf40e3585);
+	RNDr(S, W, 47, 0x106aa070);
+	RNDr(S, W, 48, 0x19a4c116);
+	RNDr(S, W, 49, 0x1e376c08);
+	RNDr(S, W, 50, 0x2748774c);
+	RNDr(S, W, 51, 0x34b0bcb5);
+	RNDr(S, W, 52, 0x391c0cb3);
+	RNDr(S, W, 53, 0x4ed8aa4a);
+	RNDr(S, W, 54, 0x5b9cca4f);
+	RNDr(S, W, 55, 0x682e6ff3);
+	RNDr(S, W, 56, 0x748f82ee);
+	RNDr(S, W, 57, 0x78a5636f);
+	RNDr(S, W, 58, 0x84c87814);
+	RNDr(S, W, 59, 0x8cc70208);
+	RNDr(S, W, 60, 0x90befffa);
+	RNDr(S, W, 61, 0xa4506ceb);
+	RNDr(S, W, 62, 0xbef9a3f7);
+	RNDr(S, W, 63, 0xc67178f2);
+
+	/* 4. Mix local working variables into global state */
+	for (i = 0; i < 8; i++)
+		state[i] += S[i];
+}
+
+static unsigned char PAD[64] = {
+	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+/* Add padding and terminating bit-count. */
+static void
+SHA256_Pad(SHA256_CTX * ctx)
+{
+	unsigned char len[8];
+	uint32_t r, plen;
+
+	/*
+	 * Convert length to a vector of bytes -- we do this now rather
+	 * than later because the length will change after we pad.
+	 */
+	be32enc_vect(len, ctx->count, 8);
+
+	/* Add 1--64 bytes so that the resulting length is 56 mod 64 */
+	r = (ctx->count[1] >> 3) & 0x3f;
+	plen = (r < 56) ? (56 - r) : (120 - r);
+	SHA256_Update(ctx, PAD, (size_t)plen);
+
+	/* Add the terminating bit-count */
+	SHA256_Update(ctx, len, 8);
+}
+
+/* SHA-256 initialization.  Begins a SHA-256 operation. */
+void
+SHA256_Init(SHA256_CTX * ctx)
+{
+
+	/* Zero bits processed so far */
+	ctx->count[0] = ctx->count[1] = 0;
+
+	/* Magic initialization constants */
+	ctx->state[0] = 0x6A09E667;
+	ctx->state[1] = 0xBB67AE85;
+	ctx->state[2] = 0x3C6EF372;
+	ctx->state[3] = 0xA54FF53A;
+	ctx->state[4] = 0x510E527F;
+	ctx->state[5] = 0x9B05688C;
+	ctx->state[6] = 0x1F83D9AB;
+	ctx->state[7] = 0x5BE0CD19;
+}
+
+/* Add bytes into the hash */
+void
+SHA256_Update(SHA256_CTX * ctx, const unsigned char *src, size_t len)
+{
+	uint32_t bitlen[2];
+	uint32_t r;
+
+	/* Number of bytes left in the buffer from previous updates */
+	r = (ctx->count[1] >> 3) & 0x3f;
+
+	/* Convert the length into a number of bits */
+	bitlen[1] = ((uint32_t)len) << 3;
+	bitlen[0] = (uint32_t)(len >> 29);
+
+	/* Update number of bits */
+	if ((ctx->count[1] += bitlen[1]) < bitlen[1])
+		ctx->count[0]++;
+	ctx->count[0] += bitlen[0];
+
+	/* Handle the case where we don't need to perform any transforms */
+	if (len < 64 - r) {
+		memcpy(&ctx->buf[r], src, len);
+		return;
+	}
+
+	/* Finish the current block */
+	memcpy(&ctx->buf[r], src, 64 - r);
+	SHA256_Transform(ctx->state, ctx->buf);
+	src += 64 - r;
+	len -= 64 - r;
+
+	/* Perform complete blocks */
+	while (len >= 64) {
+		SHA256_Transform(ctx->state, src);
+		src += 64;
+		len -= 64;
+	}
+
+	/* Copy left over data into buffer */
+	memcpy(ctx->buf, src, len);
+}
+
+/*
+ * SHA-256 finalization.  Pads the input data, exports the hash value,
+ * and clears the context state.
+ */
+void
+SHA256_Final(unsigned char digest[32], SHA256_CTX * ctx)
+{
+
+	/* Add padding */
+	SHA256_Pad(ctx);
+
+	/* Write the hash */
+	be32enc_vect(digest, ctx->state, 32);
+
+	/* Clear the context state */
+	memset((void *)ctx, 0, sizeof(*ctx));
+}
diff --git a/lib/libmd/shadriver.c b/lib/libmd/shadriver.c
index 4dd9078..7f799fb 100644
--- a/lib/libmd/shadriver.c
+++ b/lib/libmd/shadriver.c
@@ -29,8 +29,11 @@ __FBSDID("$FreeBSD$");
 #include <time.h>
 #include <string.h>
 #include "sha.h"
+#include "sha256.h"
 #if SHA == 1
 #define SHA_Data SHA1_Data
+#elif SHA == 256
+#define SHA_Data SHA256_Data
 #endif
 
 /* Digests a string and prints the result.
@@ -38,7 +41,7 @@ __FBSDID("$FreeBSD$");
 static void SHAString (string)
 char *string;
 {
-  char buf[2*20+1];
+  char buf[2*32+1];
 
   printf ("SHA-%d (\"%s\") = %s\n", 
 	SHA, string, SHA_Data(string,strlen(string),buf));