Add basic checksum algorithms

The SHA-1 and MD5 digests here are used for checksums in legacy
protocols. We don't use them in cryptographic contexts at all.
These particular algorithms would be poor choices for that.

6 files changed, 766 insertions, 2 deletions

diff --git a/.gitignore b/.gitignore
index b69b334..5c4792d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,9 +46,9 @@ stamp-h1
 temp.txt
 
 /*/tests/test-*
-!/*/tests/test-*.c
+!/*/tests/test-*.[ch]
 /*/tests/frob-*
-!/*/tests/frob-*.c
+!/*/tests/frob-*.[ch]
 
 /build/m4/*.m4
 /build/coverage
diff --git a/common/Makefile.am b/common/Makefile.am
index 972c703..aae9b35 100644
--- a/common/Makefile.am
+++ b/common/Makefile.am
@@ -26,6 +26,15 @@ libp11_library_la_SOURCES = \
 	dict.c dict.h \
 	library.c library.h \
 	pkcs11.h pkcs11x.h \
+	pkix.asn pkix.asn.h \
+	$(NULL)
+
+noinst_LTLIBRARIES += \
+	libp11-data.la \
+	$(NULL)
+
+libp11_data_la_SOURCES = \
+	checksum.c checksum.h \
 	$(NULL)
 
 libp11_mock_la_SOURCES = \
diff --git a/common/checksum.c b/common/checksum.c
new file mode 100644
index 0000000..9532308
--- /dev/null
+++ b/common/checksum.c
@@ -0,0 +1,542 @@
+/*
+ * Copyright (C) 2004, 2005, 2007, 2011  Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (C) 2000, 2001, 2003  Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*! \file
+ * SHA-1 in C
+ * \author By Steve Reid <steve@edmweb.com>
+ * 100% Public Domain
+ * \verbatim
+ * Test Vectors
+ * "abc"
+ *   A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
+ * "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
+ *   84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
+ * A million repetitions of "a"
+ *   34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
+ * \endverbatim
+ */
+
+#include "config.h"
+
+#include "checksum.h"
+
+#include <assert.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <string.h>
+
+#define SHA1_BLOCK_LENGTH 64U
+
+typedef struct {
+	uint32_t state[5];
+	uint32_t count[2];
+	unsigned char buffer[SHA1_BLOCK_LENGTH];
+} sha1_t;
+
+#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
+
+/*@{*/
+/*!
+ * blk0() and blk() perform the initial expand.
+ * I got the idea of expanding during the round function from SSLeay
+ */
+#if !defined(WORDS_BIGENDIAN)
+# define blk0(i) \
+	(block->l[i] = (rol(block->l[i], 24) & 0xFF00FF00) \
+	 | (rol(block->l[i], 8) & 0x00FF00FF))
+#else
+# define blk0(i) block->l[i]
+#endif
+#define blk(i) \
+	(block->l[i & 15] = rol(block->l[(i + 13) & 15] \
+				^ block->l[(i + 8) & 15] \
+				^ block->l[(i + 2) & 15] \
+				^ block->l[i & 15], 1))
+
+/*@}*/
+/*@{*/
+/*!
+ * (R0+R1), R2, R3, R4 are the different operations (rounds) used in SHA1
+ */
+#define R0(v,w,x,y,z,i) \
+	z += ((w & (x ^ y)) ^ y) + blk0(i) + 0x5A827999 + rol(v, 5); \
+	w = rol(w, 30);
+#define R1(v,w,x,y,z,i) \
+	z += ((w & (x ^ y)) ^ y) + blk(i) + 0x5A827999 + rol(v, 5); \
+	w = rol(w, 30);
+#define R2(v,w,x,y,z,i) \
+	z += (w ^ x ^ y) + blk(i) + 0x6ED9EBA1 + rol(v, 5); \
+	w = rol(w, 30);
+#define R3(v,w,x,y,z,i) \
+	z += (((w | x) & y) | (w & x)) + blk(i) + 0x8F1BBCDC + rol(v, 5); \
+	w = rol(w, 30);
+#define R4(v,w,x,y,z,i) \
+	z += (w ^ x ^ y) + blk(i) + 0xCA62C1D6 + rol(v, 5); \
+	w = rol(w, 30);
+
+/*@}*/
+
+typedef union {
+	unsigned char c[64];
+	unsigned int l[16];
+} CHAR64LONG16;
+
+/*!
+ * Hash a single 512-bit block. This is the core of the algorithm.
+ */
+static void
+transform_sha1 (uint32_t state[5],
+                const unsigned char buffer[64])
+{
+	uint32_t a, b, c, d, e;
+	CHAR64LONG16 *block;
+	CHAR64LONG16 workspace;
+
+	assert (buffer != NULL);
+	assert (state != NULL);
+
+	block = &workspace;
+	(void)memcpy(block, buffer, 64);
+
+	/* Copy context->state[] to working vars */
+	a = state[0];
+	b = state[1];
+	c = state[2];
+	d = state[3];
+	e = state[4];
+
+	/* 4 rounds of 20 operations each. Loop unrolled. */
+	R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
+	R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
+	R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
+	R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
+	R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
+	R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
+	R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
+	R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
+	R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
+	R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
+	R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
+	R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
+	R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
+	R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
+	R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
+	R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
+	R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
+	R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
+	R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
+	R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
+
+	/* Add the working vars back into context.state[] */
+	state[0] += a;
+	state[1] += b;
+	state[2] += c;
+	state[3] += d;
+	state[4] += e;
+
+	/* Wipe variables */
+	a = b = c = d = e = 0;
+	/* Avoid compiler warnings
+	POST(a); POST(b); POST(c); POST(d); POST(e);
+	*/
+}
+
+
+/*!
+ * isc_sha1_init - Initialize new context
+ */
+static void
+sha1_init (sha1_t *context)
+{
+	assert (context != NULL);
+
+	/* SHA1 initialization constants */
+	context->state[0] = 0x67452301;
+	context->state[1] = 0xEFCDAB89;
+	context->state[2] = 0x98BADCFE;
+	context->state[3] = 0x10325476;
+	context->state[4] = 0xC3D2E1F0;
+	context->count[0] = 0;
+	context->count[1] = 0;
+}
+
+static void
+sha1_invalidate (sha1_t *context)
+{
+	memset (context, 0, sizeof (sha1_t));
+}
+
+/*!
+ * Run your data through this.
+ */
+static void
+sha1_update(sha1_t *context,
+            const unsigned char *data,
+            unsigned int len)
+{
+	unsigned int i, j;
+
+	assert (context != 0);
+	assert (data != 0);
+
+	j = context->count[0];
+	if ((context->count[0] += len << 3) < j)
+		context->count[1] += (len >> 29) + 1;
+	j = (j >> 3) & 63;
+	if ((j + len) > 63) {
+		(void)memcpy(&context->buffer[j], data, (i = 64 - j));
+		transform_sha1 (context->state, context->buffer);
+		for (; i + 63 < len; i += 64)
+			transform_sha1 (context->state, &data[i]);
+		j = 0;
+	} else {
+		i = 0;
+	}
+
+	(void)memcpy(&context->buffer[j], &data[i], len - i);
+}
+
+
+/*!
+ * Add padding and return the message digest.
+ */
+
+static const unsigned char final_200 = 128;
+static const unsigned char final_0 = 0;
+
+static void
+sha1_final (sha1_t *context,
+            unsigned char *digest)
+{
+	unsigned int i;
+	unsigned char finalcount[8];
+
+	assert (digest != 0);
+	assert (context != 0);
+
+	for (i = 0; i < 8; i++) {
+		/* Endian independent */
+		finalcount[i] = (unsigned char)
+			((context->count[(i >= 4 ? 0 : 1)]
+			  >> ((3 - (i & 3)) * 8)) & 255);
+	}
+
+	sha1_update(context, &final_200, 1);
+	while ((context->count[0] & 504) != 448)
+		sha1_update(context, &final_0, 1);
+	/* The next Update should cause a transform_sha1() */
+	sha1_update(context, finalcount, 8);
+
+	if (digest) {
+		for (i = 0; i < 20; i++)
+			digest[i] = (unsigned char)
+				((context->state[i >> 2]
+				  >> ((3 - (i & 3)) * 8)) & 255);
+	}
+
+	memset (context, 0, sizeof (sha1_t));
+}
+
+void
+p11_checksum_sha1 (unsigned char *checksum,
+                   const void *input,
+                   size_t length,
+                   ...)
+{
+	va_list va;
+	sha1_t sha1;
+
+	sha1_init (&sha1);
+
+	va_start (va, length);
+	while (input != NULL) {
+		sha1_update (&sha1, input, length);
+		input = va_arg (va, const void *);
+		if (input)
+			length = va_arg (va, size_t);
+	}
+	va_end (va);
+
+	sha1_final (&sha1, checksum);
+	sha1_invalidate (&sha1);
+}
+
+
+/*! \file
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.  This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ */
+
+typedef struct {
+	uint32_t buf[4];
+	uint32_t bytes[2];
+	uint32_t in[16];
+} md5_t;
+
+static void
+byteSwap (uint32_t *buf,
+          unsigned words)
+{
+	unsigned char *p = (unsigned char *)buf;
+
+	do {
+		*buf++ = (uint32_t)((unsigned)p[3] << 8 | p[2]) << 16 |
+			((unsigned)p[1] << 8 | p[0]);
+		p += 4;
+	} while (--words);
+}
+
+/*!
+ * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
+ * initialization constants.
+ */
+static void
+md5_init(md5_t *ctx)
+{
+	ctx->buf[0] = 0x67452301;
+	ctx->buf[1] = 0xefcdab89;
+	ctx->buf[2] = 0x98badcfe;
+	ctx->buf[3] = 0x10325476;
+
+	ctx->bytes[0] = 0;
+	ctx->bytes[1] = 0;
+}
+
+static void
+md5_invalidate(md5_t *ctx)
+{
+	memset(ctx, 0, sizeof(md5_t));
+}
+
+/*@{*/
+/*! The four core functions - F1 is optimized somewhat */
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+/*@}*/
+
+/*! This is the central step in the MD5 algorithm. */
+#define MD5STEP(f,w,x,y,z,in,s) \
+	 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
+
+/*!
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data.  MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+static void
+transform_md5 (uint32_t buf[4],
+               uint32_t const in[16])
+{
+	register uint32_t a, b, c, d;
+
+	a = buf[0];
+	b = buf[1];
+	c = buf[2];
+	d = buf[3];
+
+	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
+	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
+	MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
+	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
+	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
+	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
+	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
+	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
+	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
+	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
+	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
+	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
+	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
+	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
+	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
+	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
+
+	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
+	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
+	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
+	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
+	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
+	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
+	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
+	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
+	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
+	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
+	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
+	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
+	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
+	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
+	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
+	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
+
+	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
+	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
+	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
+	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
+	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
+	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
+	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
+	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
+	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
+	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
+	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
+	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
+	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
+	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
+	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
+	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
+
+	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
+	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
+	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
+	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
+	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
+	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
+	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
+	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
+	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
+	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
+	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
+	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
+	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
+	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
+	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
+	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
+
+	buf[0] += a;
+	buf[1] += b;
+	buf[2] += c;
+	buf[3] += d;
+}
+
+/*!
+ * Update context to reflect the concatenation of another buffer full
+ * of bytes.
+ */
+static void
+md5_update (md5_t *ctx,
+            const unsigned char *buf,
+            unsigned int len)
+{
+	uint32_t t;
+
+	/* Update byte count */
+
+	t = ctx->bytes[0];
+	if ((ctx->bytes[0] = t + len) < t)
+		ctx->bytes[1]++;	/* Carry from low to high */
+
+	t = 64 - (t & 0x3f);	/* Space available in ctx->in (at least 1) */
+	if (t > len) {
+		memcpy((unsigned char *)ctx->in + 64 - t, buf, len);
+		return;
+	}
+	/* First chunk is an odd size */
+	memcpy((unsigned char *)ctx->in + 64 - t, buf, t);
+	byteSwap(ctx->in, 16);
+	transform_md5 (ctx->buf, ctx->in);
+	buf += t;
+	len -= t;
+
+	/* Process data in 64-byte chunks */
+	while (len >= 64) {
+		memcpy(ctx->in, buf, 64);
+		byteSwap(ctx->in, 16);
+		transform_md5(ctx->buf, ctx->in);
+		buf += 64;
+		len -= 64;
+	}
+
+	/* Handle any remaining bytes of data. */
+	memcpy(ctx->in, buf, len);
+}
+
+/*!
+ * Final wrapup - pad to 64-byte boundary with the bit pattern
+ * 1 0* (64-bit count of bits processed, MSB-first)
+ */
+static void
+md5_final(md5_t *ctx,
+          unsigned char *digest)
+{
+	int count = ctx->bytes[0] & 0x3f;    /* Number of bytes in ctx->in */
+	unsigned char *p = (unsigned char *)ctx->in + count;
+
+	/* Set the first char of padding to 0x80.  There is always room. */
+	*p++ = 0x80;
+
+	/* Bytes of padding needed to make 56 bytes (-8..55) */
+	count = 56 - 1 - count;
+
+	if (count < 0) {	/* Padding forces an extra block */
+		memset(p, 0, count + 8);
+		byteSwap(ctx->in, 16);
+		transform_md5(ctx->buf, ctx->in);
+		p = (unsigned char *)ctx->in;
+		count = 56;
+	}
+	memset(p, 0, count);
+	byteSwap(ctx->in, 14);
+
+	/* Append length in bits and transform */
+	ctx->in[14] = ctx->bytes[0] << 3;
+	ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
+	transform_md5(ctx->buf, ctx->in);
+
+	byteSwap(ctx->buf, 4);
+	memcpy(digest, ctx->buf, 16);
+	memset(ctx, 0, sizeof(md5_t));	/* In case it's sensitive */
+}
+
+void
+p11_checksum_md5 (unsigned char *checksum,
+                  const void *input,
+                  size_t length,
+                  ...)
+{
+	va_list va;
+	md5_t md5;
+
+	md5_init (&md5);
+
+	va_start (va, length);
+	while (input) {
+		md5_update (&md5, input, length);
+		input = va_arg (va, const void *);
+		if (input)
+			length = va_arg (va, size_t);
+	}
+	va_end (va);
+
+	md5_final (&md5, checksum);
+	md5_invalidate (&md5);
+}
diff --git a/common/checksum.h b/common/checksum.h
new file mode 100644
index 0000000..c688398
--- /dev/null
+++ b/common/checksum.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2012 Red Hat Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *     * Redistributions of source code must retain the above
+ *       copyright notice, this list of conditions and the
+ *       following disclaimer.
+ *     * 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.
+ *     * The names of contributors to this software may not be
+ *       used to endorse or promote products derived from this
+ *       software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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.
+ *
+ * Author: Stef Walter <stefw@redhat.com>
+ */
+
+#ifndef P11_CHECKSUM_H_
+#define P11_CHECKSUM_H_
+
+#include "compat.h"
+
+/*
+ * The SHA-1 and MD5 digests here are used for checksums in legacy
+ * protocols. We don't use them in cryptographic contexts at all.
+ * These particular algorithms would be poor choices for that.
+ */
+
+#define P11_CHECKSUM_SHA1_LENGTH 20
+
+#define P11_CHECKSUM_MD5_LENGTH 16
+
+void     p11_checksum_md5       (unsigned char *checksum,
+                                 const void *input,
+                                 size_t length,
+                                 ...) GNUC_NULL_TERMINATED;
+
+void     p11_checksum_sha1      (unsigned char *checksum,
+                                 const void *input,
+                                 size_t length,
+                                 ...) GNUC_NULL_TERMINATED;
+
+#endif /* P11_CHECKSUM_H_ */
diff --git a/common/tests/Makefile.am b/common/tests/Makefile.am
index 3b6b986..e3f2063 100644
--- a/common/tests/Makefile.am
+++ b/common/tests/Makefile.am
@@ -14,10 +14,12 @@ INCLUDES = \
 LDADD = \
 	$(top_builddir)/common/libp11-library.la \
 	$(top_builddir)/common/libp11-compat.la \
+	$(top_builddir)/common/libp11-data.la \
 	$(CUTEST_LIBS) \
 	$(NULL)
 
 CHECK_PROGS = \
+	test-checksum \
 	test-dict \
 	test-array \
 	test-attrs \
diff --git a/common/tests/test-checksum.c b/common/tests/test-checksum.c
new file mode 100644
index 0000000..5604aad
--- /dev/null
+++ b/common/tests/test-checksum.c
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2012 Red Hat Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *     * Redistributions of source code must retain the above
+ *       copyright notice, this list of conditions and the
+ *       following disclaimer.
+ *     * 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.
+ *     * The names of contributors to this software may not be
+ *       used to endorse or promote products derived from this
+ *       software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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.
+ *
+ * Author: Stef Walter <stefw@gnome.org>
+ */
+
+#include "config.h"
+#include "CuTest.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "checksum.h"
+
+const char *sha1_input[] = {
+	"abc",
+	"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
+	NULL
+};
+
+const char *sha1_checksum[] = {
+	"\xA9\x99\x3E\x36\x47\x06\x81\x6A\xBA\x3E\x25\x71\x78\x50\xC2\x6C\x9C\xD0\xD8\x9D",
+	"\x84\x98\x3E\x44\x1C\x3B\xD2\x6E\xBA\xAE\x4A\xA1\xF9\x51\x29\xE5\xE5\x46\x70\xF1",
+	NULL
+};
+
+static void
+test_sha1 (CuTest *cu)
+{
+	unsigned char checksum[P11_CHECKSUM_SHA1_LENGTH];
+	size_t len;
+	int i;
+
+	for (i = 0; sha1_input[i] != NULL; i++) {
+		memset (checksum, 0, sizeof (checksum));
+		len = strlen (sha1_input[i]);
+
+		p11_checksum_sha1 (checksum, sha1_input[i], len, NULL);
+		CuAssertTrue (cu, memcmp (sha1_checksum[i], checksum, P11_CHECKSUM_SHA1_LENGTH) == 0);
+
+		if (len > 6) {
+			p11_checksum_sha1 (checksum, sha1_input[i], 6, sha1_input[i] + 6, len - 6, NULL);
+			CuAssertTrue (cu, memcmp (sha1_checksum[i], checksum, P11_CHECKSUM_SHA1_LENGTH) == 0);
+		}
+	}
+}
+
+static void
+test_sha1_long (CuTest *cu)
+{
+	unsigned char checksum[P11_CHECKSUM_SHA1_LENGTH];
+	char *expected = "\x34\xAA\x97\x3C\xD4\xC4\xDA\xA4\xF6\x1E\xEB\x2B\xDB\xAD\x27\x31\x65\x34\x01\x6F";
+	char *input;
+
+	input = malloc (1000000);
+	CuAssertTrue (cu, input != NULL);
+	memset (input, 'a', 1000000);
+
+	p11_checksum_sha1 (checksum, input, strlen (input), NULL);
+	CuAssertTrue (cu, memcmp (expected, checksum, P11_CHECKSUM_SHA1_LENGTH) == 0);
+}
+
+const char *md5_input[] = {
+	"",
+	"a",
+	"abc",
+	"message digest",
+	"abcdefghijklmnopqrstuvwxyz",
+	NULL
+};
+
+const char *md5_checksum[] = {
+	"\xd4\x1d\x8c\xd9\x8f\x00\xb2\x04\xe9\x80\x09\x98\xec\xf8\x42\x7e",
+	"\x0c\xc1\x75\xb9\xc0\xf1\xb6\xa8\x31\xc3\x99\xe2\x69\x77\x26\x61",
+	"\x90\x01\x50\x98\x3c\xd2\x4f\xb0\xd6\x96\x3f\x7d\x28\xe1\x7f\x72",
+	"\xf9\x6b\x69\x7d\x7c\xb7\x93\x8d\x52\x5a\x2f\x31\xaa\xf1\x61\xd0",
+	"\xc3\xfc\xd3\xd7\x61\x92\xe4\x00\x7d\xfb\x49\x6c\xca\x67\xe1\x3b",
+	NULL
+};
+
+static void
+test_md5 (CuTest *cu)
+{
+	unsigned char checksum[P11_CHECKSUM_MD5_LENGTH];
+	size_t len;
+	int i;
+
+	for (i = 0; md5_input[i] != NULL; i++) {
+		memset (checksum, 0, sizeof (checksum));
+		len = strlen (md5_input[i]);
+
+		p11_checksum_md5 (checksum, md5_input[i], len, NULL);
+		CuAssertTrue (cu, memcmp (md5_checksum[i], checksum, P11_CHECKSUM_MD5_LENGTH) == 0);
+
+		if (len > 5) {
+			p11_checksum_md5 (checksum, md5_input[i], 5, md5_input[i] + 5, len - 5, NULL);
+			CuAssertTrue (cu, memcmp (md5_checksum[i], checksum, P11_CHECKSUM_MD5_LENGTH) == 0);
+		}
+	}
+}
+
+int
+main (void)
+{
+	CuString *output = CuStringNew ();
+	CuSuite* suite = CuSuiteNew ();
+	int ret;
+
+	SUITE_ADD_TEST (suite, test_sha1);
+	SUITE_ADD_TEST (suite, test_sha1_long);
+	SUITE_ADD_TEST (suite, test_md5);
+
+	CuSuiteRun (suite);
+	CuSuiteSummary (suite, output);
+	CuSuiteDetails (suite, output);
+	printf ("%s\n", output->buffer);
+	ret = suite->failCount;
+	CuSuiteDelete (suite);
+	CuStringDelete (output);
+
+	return ret;
+}