plink: updated to revision 10170 of putty

1 files changed, 340 insertions, 344 deletions

diff --git a/tools/plink/sshmd5.c b/tools/plink/sshmd5.c
index 80474dfad..2fdb59007 100644
--- a/tools/plink/sshmd5.c
+++ b/tools/plink/sshmd5.c
@@ -1,344 +1,340 @@
-#include "ssh.h"

-

-/*

- * MD5 implementation for PuTTY. Written directly from the spec by

- * Simon Tatham.

- */

-

-/* ----------------------------------------------------------------------

- * Core MD5 algorithm: processes 16-word blocks into a message digest.

- */

-

-#define F(x,y,z) ( ((x) & (y)) | ((~(x)) & (z)) )

-#define G(x,y,z) ( ((x) & (z)) | ((~(z)) & (y)) )

-#define H(x,y,z) ( (x) ^ (y) ^ (z) )

-#define I(x,y,z) ( (y) ^ ( (x) | ~(z) ) )

-

-#define rol(x,y) ( ((x) << (y)) | (((uint32)x) >> (32-y)) )

-

-#define subround(f,w,x,y,z,k,s,ti) \

-       w = x + rol(w + f(x,y,z) + block[k] + ti, s)

-

-static void MD5_Core_Init(MD5_Core_State * s)

-{

-    s->h[0] = 0x67452301;

-    s->h[1] = 0xefcdab89;

-    s->h[2] = 0x98badcfe;

-    s->h[3] = 0x10325476;

-}

-

-static void MD5_Block(MD5_Core_State * s, uint32 * block)

-{

-    uint32 a, b, c, d;

-

-    a = s->h[0];

-    b = s->h[1];

-    c = s->h[2];

-    d = s->h[3];

-

-    subround(F, a, b, c, d, 0, 7, 0xd76aa478);

-    subround(F, d, a, b, c, 1, 12, 0xe8c7b756);

-    subround(F, c, d, a, b, 2, 17, 0x242070db);

-    subround(F, b, c, d, a, 3, 22, 0xc1bdceee);

-    subround(F, a, b, c, d, 4, 7, 0xf57c0faf);

-    subround(F, d, a, b, c, 5, 12, 0x4787c62a);

-    subround(F, c, d, a, b, 6, 17, 0xa8304613);

-    subround(F, b, c, d, a, 7, 22, 0xfd469501);

-    subround(F, a, b, c, d, 8, 7, 0x698098d8);

-    subround(F, d, a, b, c, 9, 12, 0x8b44f7af);

-    subround(F, c, d, a, b, 10, 17, 0xffff5bb1);

-    subround(F, b, c, d, a, 11, 22, 0x895cd7be);

-    subround(F, a, b, c, d, 12, 7, 0x6b901122);

-    subround(F, d, a, b, c, 13, 12, 0xfd987193);

-    subround(F, c, d, a, b, 14, 17, 0xa679438e);

-    subround(F, b, c, d, a, 15, 22, 0x49b40821);

-    subround(G, a, b, c, d, 1, 5, 0xf61e2562);

-    subround(G, d, a, b, c, 6, 9, 0xc040b340);

-    subround(G, c, d, a, b, 11, 14, 0x265e5a51);

-    subround(G, b, c, d, a, 0, 20, 0xe9b6c7aa);

-    subround(G, a, b, c, d, 5, 5, 0xd62f105d);

-    subround(G, d, a, b, c, 10, 9, 0x02441453);

-    subround(G, c, d, a, b, 15, 14, 0xd8a1e681);

-    subround(G, b, c, d, a, 4, 20, 0xe7d3fbc8);

-    subround(G, a, b, c, d, 9, 5, 0x21e1cde6);

-    subround(G, d, a, b, c, 14, 9, 0xc33707d6);

-    subround(G, c, d, a, b, 3, 14, 0xf4d50d87);

-    subround(G, b, c, d, a, 8, 20, 0x455a14ed);

-    subround(G, a, b, c, d, 13, 5, 0xa9e3e905);

-    subround(G, d, a, b, c, 2, 9, 0xfcefa3f8);

-    subround(G, c, d, a, b, 7, 14, 0x676f02d9);

-    subround(G, b, c, d, a, 12, 20, 0x8d2a4c8a);

-    subround(H, a, b, c, d, 5, 4, 0xfffa3942);

-    subround(H, d, a, b, c, 8, 11, 0x8771f681);

-    subround(H, c, d, a, b, 11, 16, 0x6d9d6122);

-    subround(H, b, c, d, a, 14, 23, 0xfde5380c);

-    subround(H, a, b, c, d, 1, 4, 0xa4beea44);

-    subround(H, d, a, b, c, 4, 11, 0x4bdecfa9);

-    subround(H, c, d, a, b, 7, 16, 0xf6bb4b60);

-    subround(H, b, c, d, a, 10, 23, 0xbebfbc70);

-    subround(H, a, b, c, d, 13, 4, 0x289b7ec6);

-    subround(H, d, a, b, c, 0, 11, 0xeaa127fa);

-    subround(H, c, d, a, b, 3, 16, 0xd4ef3085);

-    subround(H, b, c, d, a, 6, 23, 0x04881d05);

-    subround(H, a, b, c, d, 9, 4, 0xd9d4d039);

-    subround(H, d, a, b, c, 12, 11, 0xe6db99e5);

-    subround(H, c, d, a, b, 15, 16, 0x1fa27cf8);

-    subround(H, b, c, d, a, 2, 23, 0xc4ac5665);

-    subround(I, a, b, c, d, 0, 6, 0xf4292244);

-    subround(I, d, a, b, c, 7, 10, 0x432aff97);

-    subround(I, c, d, a, b, 14, 15, 0xab9423a7);

-    subround(I, b, c, d, a, 5, 21, 0xfc93a039);

-    subround(I, a, b, c, d, 12, 6, 0x655b59c3);

-    subround(I, d, a, b, c, 3, 10, 0x8f0ccc92);

-    subround(I, c, d, a, b, 10, 15, 0xffeff47d);

-    subround(I, b, c, d, a, 1, 21, 0x85845dd1);

-    subround(I, a, b, c, d, 8, 6, 0x6fa87e4f);

-    subround(I, d, a, b, c, 15, 10, 0xfe2ce6e0);

-    subround(I, c, d, a, b, 6, 15, 0xa3014314);

-    subround(I, b, c, d, a, 13, 21, 0x4e0811a1);

-    subround(I, a, b, c, d, 4, 6, 0xf7537e82);

-    subround(I, d, a, b, c, 11, 10, 0xbd3af235);

-    subround(I, c, d, a, b, 2, 15, 0x2ad7d2bb);

-    subround(I, b, c, d, a, 9, 21, 0xeb86d391);

-

-    s->h[0] += a;

-    s->h[1] += b;

-    s->h[2] += c;

-    s->h[3] += d;

-}

-

-/* ----------------------------------------------------------------------

- * Outer MD5 algorithm: take an arbitrary length byte string,

- * convert it into 16-word blocks with the prescribed padding at

- * the end, and pass those blocks to the core MD5 algorithm.

- */

-

-#define BLKSIZE 64

-

-void MD5Init(struct MD5Context *s)

-{

-    MD5_Core_Init(&s->core);

-    s->blkused = 0;

-    s->lenhi = s->lenlo = 0;

-}

-

-void MD5Update(struct MD5Context *s, unsigned char const *p, unsigned len)

-{

-    unsigned char *q = (unsigned char *) p;

-    uint32 wordblock[16];

-    uint32 lenw = len;

-    int i;

-

-    /*

-     * Update the length field.

-     */

-    s->lenlo += lenw;

-    s->lenhi += (s->lenlo < lenw);

-

-    if (s->blkused + len < BLKSIZE) {

-	/*

-	 * Trivial case: just add to the block.

-	 */

-	memcpy(s->block + s->blkused, q, len);

-	s->blkused += len;

-    } else {

-	/*

-	 * We must complete and process at least one block.

-	 */

-	while (s->blkused + len >= BLKSIZE) {

-	    memcpy(s->block + s->blkused, q, BLKSIZE - s->blkused);

-	    q += BLKSIZE - s->blkused;

-	    len -= BLKSIZE - s->blkused;

-	    /* Now process the block. Gather bytes little-endian into words */

-	    for (i = 0; i < 16; i++) {

-		wordblock[i] =

-		    (((uint32) s->block[i * 4 + 3]) << 24) |

-		    (((uint32) s->block[i * 4 + 2]) << 16) |

-		    (((uint32) s->block[i * 4 + 1]) << 8) |

-		    (((uint32) s->block[i * 4 + 0]) << 0);

-	    }

-	    MD5_Block(&s->core, wordblock);

-	    s->blkused = 0;

-	}

-	memcpy(s->block, q, len);

-	s->blkused = len;

-    }

-}

-

-void MD5Final(unsigned char output[16], struct MD5Context *s)

-{

-    int i;

-    unsigned pad;

-    unsigned char c[64];

-    uint32 lenhi, lenlo;

-

-    if (s->blkused >= 56)

-	pad = 56 + 64 - s->blkused;

-    else

-	pad = 56 - s->blkused;

-

-    lenhi = (s->lenhi << 3) | (s->lenlo >> (32 - 3));

-    lenlo = (s->lenlo << 3);

-

-    memset(c, 0, pad);

-    c[0] = 0x80;

-    MD5Update(s, c, pad);

-

-    c[7] = (lenhi >> 24) & 0xFF;

-    c[6] = (lenhi >> 16) & 0xFF;

-    c[5] = (lenhi >> 8) & 0xFF;

-    c[4] = (lenhi >> 0) & 0xFF;

-    c[3] = (lenlo >> 24) & 0xFF;

-    c[2] = (lenlo >> 16) & 0xFF;

-    c[1] = (lenlo >> 8) & 0xFF;

-    c[0] = (lenlo >> 0) & 0xFF;

-

-    MD5Update(s, c, 8);

-

-    for (i = 0; i < 4; i++) {

-	output[4 * i + 3] = (s->core.h[i] >> 24) & 0xFF;

-	output[4 * i + 2] = (s->core.h[i] >> 16) & 0xFF;

-	output[4 * i + 1] = (s->core.h[i] >> 8) & 0xFF;

-	output[4 * i + 0] = (s->core.h[i] >> 0) & 0xFF;

-    }

-}

-

-void MD5Simple(void const *p, unsigned len, unsigned char output[16])

-{

-    struct MD5Context s;

-

-    MD5Init(&s);

-    MD5Update(&s, (unsigned char const *)p, len);

-    MD5Final(output, &s);

-}

-

-/* ----------------------------------------------------------------------

- * The above is the MD5 algorithm itself. Now we implement the

- * HMAC wrapper on it.

- * 

- * Some of these functions are exported directly, because they are

- * useful elsewhere (SOCKS5 CHAP authentication uses HMAC-MD5).

- */

-

-void *hmacmd5_make_context(void)

-{

-    return snewn(3, struct MD5Context);

-}

-

-void hmacmd5_free_context(void *handle)

-{

-    sfree(handle);

-}

-

-void hmacmd5_key(void *handle, void const *keyv, int len)

-{

-    struct MD5Context *keys = (struct MD5Context *)handle;

-    unsigned char foo[64];

-    unsigned char const *key = (unsigned char const *)keyv;

-    int i;

-

-    memset(foo, 0x36, 64);

-    for (i = 0; i < len && i < 64; i++)

-	foo[i] ^= key[i];

-    MD5Init(&keys[0]);

-    MD5Update(&keys[0], foo, 64);

-

-    memset(foo, 0x5C, 64);

-    for (i = 0; i < len && i < 64; i++)

-	foo[i] ^= key[i];

-    MD5Init(&keys[1]);

-    MD5Update(&keys[1], foo, 64);

-

-    memset(foo, 0, 64);		       /* burn the evidence */

-}

-

-static void hmacmd5_key_16(void *handle, unsigned char *key)

-{

-    hmacmd5_key(handle, key, 16);

-}

-

-static void hmacmd5_start(void *handle)

-{

-    struct MD5Context *keys = (struct MD5Context *)handle;

-

-    keys[2] = keys[0];		      /* structure copy */

-}

-

-static void hmacmd5_bytes(void *handle, unsigned char const *blk, int len)

-{

-    struct MD5Context *keys = (struct MD5Context *)handle;

-    MD5Update(&keys[2], blk, len);

-}

-

-static void hmacmd5_genresult(void *handle, unsigned char *hmac)

-{

-    struct MD5Context *keys = (struct MD5Context *)handle;

-    struct MD5Context s;

-    unsigned char intermediate[16];

-

-    s = keys[2];		       /* structure copy */

-    MD5Final(intermediate, &s);

-    s = keys[1];		       /* structure copy */

-    MD5Update(&s, intermediate, 16);

-    MD5Final(hmac, &s);

-}

-

-static int hmacmd5_verresult(void *handle, unsigned char const *hmac)

-{

-    unsigned char correct[16];

-    hmacmd5_genresult(handle, correct);

-    return !memcmp(correct, hmac, 16);

-}

-

-static void hmacmd5_do_hmac_internal(void *handle,

-				     unsigned char const *blk, int len,

-				     unsigned char const *blk2, int len2,

-				     unsigned char *hmac)

-{

-    hmacmd5_start(handle);

-    hmacmd5_bytes(handle, blk, len);

-    if (blk2) hmacmd5_bytes(handle, blk2, len2);

-    hmacmd5_genresult(handle, hmac);

-}

-

-void hmacmd5_do_hmac(void *handle, unsigned char const *blk, int len,

-		     unsigned char *hmac)

-{

-    hmacmd5_do_hmac_internal(handle, blk, len, NULL, 0, hmac);

-}

-

-static void hmacmd5_do_hmac_ssh(void *handle, unsigned char const *blk, int len,

-				unsigned long seq, unsigned char *hmac)

-{

-    unsigned char seqbuf[16];

-

-    seqbuf[0] = (unsigned char) ((seq >> 24) & 0xFF);

-    seqbuf[1] = (unsigned char) ((seq >> 16) & 0xFF);

-    seqbuf[2] = (unsigned char) ((seq >> 8) & 0xFF);

-    seqbuf[3] = (unsigned char) ((seq) & 0xFF);

-

-    hmacmd5_do_hmac_internal(handle, seqbuf, 4, blk, len, hmac);

-}

-

-static void hmacmd5_generate(void *handle, unsigned char *blk, int len,

-			     unsigned long seq)

-{

-    hmacmd5_do_hmac_ssh(handle, blk, len, seq, blk + len);

-}

-

-static int hmacmd5_verify(void *handle, unsigned char *blk, int len,

-			  unsigned long seq)

-{

-    unsigned char correct[16];

-    hmacmd5_do_hmac_ssh(handle, blk, len, seq, correct);

-    return !memcmp(correct, blk + len, 16);

-}

-

-const struct ssh_mac ssh_hmac_md5 = {

-    hmacmd5_make_context, hmacmd5_free_context, hmacmd5_key_16,

-    hmacmd5_generate, hmacmd5_verify,

-    hmacmd5_start, hmacmd5_bytes, hmacmd5_genresult, hmacmd5_verresult,

-    "hmac-md5",

-    16,

-    "HMAC-MD5"

-};

+#include "ssh.h"
+
+/*
+ * MD5 implementation for PuTTY. Written directly from the spec by
+ * Simon Tatham.
+ */
+
+/* ----------------------------------------------------------------------
+ * Core MD5 algorithm: processes 16-word blocks into a message digest.
+ */
+
+#define F(x,y,z) ( ((x) & (y)) | ((~(x)) & (z)) )
+#define G(x,y,z) ( ((x) & (z)) | ((~(z)) & (y)) )
+#define H(x,y,z) ( (x) ^ (y) ^ (z) )
+#define I(x,y,z) ( (y) ^ ( (x) | ~(z) ) )
+
+#define rol(x,y) ( ((x) << (y)) | (((uint32)x) >> (32-y)) )
+
+#define subround(f,w,x,y,z,k,s,ti) \
+       w = x + rol(w + f(x,y,z) + block[k] + ti, s)
+
+static void MD5_Core_Init(MD5_Core_State * s)
+{
+    s->h[0] = 0x67452301;
+    s->h[1] = 0xefcdab89;
+    s->h[2] = 0x98badcfe;
+    s->h[3] = 0x10325476;
+}
+
+static void MD5_Block(MD5_Core_State * s, uint32 * block)
+{
+    uint32 a, b, c, d;
+
+    a = s->h[0];
+    b = s->h[1];
+    c = s->h[2];
+    d = s->h[3];
+
+    subround(F, a, b, c, d, 0, 7, 0xd76aa478);
+    subround(F, d, a, b, c, 1, 12, 0xe8c7b756);
+    subround(F, c, d, a, b, 2, 17, 0x242070db);
+    subround(F, b, c, d, a, 3, 22, 0xc1bdceee);
+    subround(F, a, b, c, d, 4, 7, 0xf57c0faf);
+    subround(F, d, a, b, c, 5, 12, 0x4787c62a);
+    subround(F, c, d, a, b, 6, 17, 0xa8304613);
+    subround(F, b, c, d, a, 7, 22, 0xfd469501);
+    subround(F, a, b, c, d, 8, 7, 0x698098d8);
+    subround(F, d, a, b, c, 9, 12, 0x8b44f7af);
+    subround(F, c, d, a, b, 10, 17, 0xffff5bb1);
+    subround(F, b, c, d, a, 11, 22, 0x895cd7be);
+    subround(F, a, b, c, d, 12, 7, 0x6b901122);
+    subround(F, d, a, b, c, 13, 12, 0xfd987193);
+    subround(F, c, d, a, b, 14, 17, 0xa679438e);
+    subround(F, b, c, d, a, 15, 22, 0x49b40821);
+    subround(G, a, b, c, d, 1, 5, 0xf61e2562);
+    subround(G, d, a, b, c, 6, 9, 0xc040b340);
+    subround(G, c, d, a, b, 11, 14, 0x265e5a51);
+    subround(G, b, c, d, a, 0, 20, 0xe9b6c7aa);
+    subround(G, a, b, c, d, 5, 5, 0xd62f105d);
+    subround(G, d, a, b, c, 10, 9, 0x02441453);
+    subround(G, c, d, a, b, 15, 14, 0xd8a1e681);
+    subround(G, b, c, d, a, 4, 20, 0xe7d3fbc8);
+    subround(G, a, b, c, d, 9, 5, 0x21e1cde6);
+    subround(G, d, a, b, c, 14, 9, 0xc33707d6);
+    subround(G, c, d, a, b, 3, 14, 0xf4d50d87);
+    subround(G, b, c, d, a, 8, 20, 0x455a14ed);
+    subround(G, a, b, c, d, 13, 5, 0xa9e3e905);
+    subround(G, d, a, b, c, 2, 9, 0xfcefa3f8);
+    subround(G, c, d, a, b, 7, 14, 0x676f02d9);
+    subround(G, b, c, d, a, 12, 20, 0x8d2a4c8a);
+    subround(H, a, b, c, d, 5, 4, 0xfffa3942);
+    subround(H, d, a, b, c, 8, 11, 0x8771f681);
+    subround(H, c, d, a, b, 11, 16, 0x6d9d6122);
+    subround(H, b, c, d, a, 14, 23, 0xfde5380c);
+    subround(H, a, b, c, d, 1, 4, 0xa4beea44);
+    subround(H, d, a, b, c, 4, 11, 0x4bdecfa9);
+    subround(H, c, d, a, b, 7, 16, 0xf6bb4b60);
+    subround(H, b, c, d, a, 10, 23, 0xbebfbc70);
+    subround(H, a, b, c, d, 13, 4, 0x289b7ec6);
+    subround(H, d, a, b, c, 0, 11, 0xeaa127fa);
+    subround(H, c, d, a, b, 3, 16, 0xd4ef3085);
+    subround(H, b, c, d, a, 6, 23, 0x04881d05);
+    subround(H, a, b, c, d, 9, 4, 0xd9d4d039);
+    subround(H, d, a, b, c, 12, 11, 0xe6db99e5);
+    subround(H, c, d, a, b, 15, 16, 0x1fa27cf8);
+    subround(H, b, c, d, a, 2, 23, 0xc4ac5665);
+    subround(I, a, b, c, d, 0, 6, 0xf4292244);
+    subround(I, d, a, b, c, 7, 10, 0x432aff97);
+    subround(I, c, d, a, b, 14, 15, 0xab9423a7);
+    subround(I, b, c, d, a, 5, 21, 0xfc93a039);
+    subround(I, a, b, c, d, 12, 6, 0x655b59c3);
+    subround(I, d, a, b, c, 3, 10, 0x8f0ccc92);
+    subround(I, c, d, a, b, 10, 15, 0xffeff47d);
+    subround(I, b, c, d, a, 1, 21, 0x85845dd1);
+    subround(I, a, b, c, d, 8, 6, 0x6fa87e4f);
+    subround(I, d, a, b, c, 15, 10, 0xfe2ce6e0);
+    subround(I, c, d, a, b, 6, 15, 0xa3014314);
+    subround(I, b, c, d, a, 13, 21, 0x4e0811a1);
+    subround(I, a, b, c, d, 4, 6, 0xf7537e82);
+    subround(I, d, a, b, c, 11, 10, 0xbd3af235);
+    subround(I, c, d, a, b, 2, 15, 0x2ad7d2bb);
+    subround(I, b, c, d, a, 9, 21, 0xeb86d391);
+
+    s->h[0] += a;
+    s->h[1] += b;
+    s->h[2] += c;
+    s->h[3] += d;
+}
+
+/* ----------------------------------------------------------------------
+ * Outer MD5 algorithm: take an arbitrary length byte string,
+ * convert it into 16-word blocks with the prescribed padding at
+ * the end, and pass those blocks to the core MD5 algorithm.
+ */
+
+#define BLKSIZE 64
+
+void MD5Init(struct MD5Context *s)
+{
+    MD5_Core_Init(&s->core);
+    s->blkused = 0;
+    s->lenhi = s->lenlo = 0;
+}
+
+void MD5Update(struct MD5Context *s, unsigned char const *p, unsigned len)
+{
+    unsigned char *q = (unsigned char *) p;
+    uint32 wordblock[16];
+    uint32 lenw = len;
+    int i;
+
+    /*
+     * Update the length field.
+     */
+    s->lenlo += lenw;
+    s->lenhi += (s->lenlo < lenw);
+
+    if (s->blkused + len < BLKSIZE) {
+	/*
+	 * Trivial case: just add to the block.
+	 */
+	memcpy(s->block + s->blkused, q, len);
+	s->blkused += len;
+    } else {
+	/*
+	 * We must complete and process at least one block.
+	 */
+	while (s->blkused + len >= BLKSIZE) {
+	    memcpy(s->block + s->blkused, q, BLKSIZE - s->blkused);
+	    q += BLKSIZE - s->blkused;
+	    len -= BLKSIZE - s->blkused;
+	    /* Now process the block. Gather bytes little-endian into words */
+	    for (i = 0; i < 16; i++) {
+		wordblock[i] =
+		    (((uint32) s->block[i * 4 + 3]) << 24) |
+		    (((uint32) s->block[i * 4 + 2]) << 16) |
+		    (((uint32) s->block[i * 4 + 1]) << 8) |
+		    (((uint32) s->block[i * 4 + 0]) << 0);
+	    }
+	    MD5_Block(&s->core, wordblock);
+	    s->blkused = 0;
+	}
+	memcpy(s->block, q, len);
+	s->blkused = len;
+    }
+}
+
+void MD5Final(unsigned char output[16], struct MD5Context *s)
+{
+    int i;
+    unsigned pad;
+    unsigned char c[64];
+    uint32 lenhi, lenlo;
+
+    if (s->blkused >= 56)
+	pad = 56 + 64 - s->blkused;
+    else
+	pad = 56 - s->blkused;
+
+    lenhi = (s->lenhi << 3) | (s->lenlo >> (32 - 3));
+    lenlo = (s->lenlo << 3);
+
+    memset(c, 0, pad);
+    c[0] = 0x80;
+    MD5Update(s, c, pad);
+
+    c[7] = (lenhi >> 24) & 0xFF;
+    c[6] = (lenhi >> 16) & 0xFF;
+    c[5] = (lenhi >> 8) & 0xFF;
+    c[4] = (lenhi >> 0) & 0xFF;
+    c[3] = (lenlo >> 24) & 0xFF;
+    c[2] = (lenlo >> 16) & 0xFF;
+    c[1] = (lenlo >> 8) & 0xFF;
+    c[0] = (lenlo >> 0) & 0xFF;
+
+    MD5Update(s, c, 8);
+
+    for (i = 0; i < 4; i++) {
+	output[4 * i + 3] = (s->core.h[i] >> 24) & 0xFF;
+	output[4 * i + 2] = (s->core.h[i] >> 16) & 0xFF;
+	output[4 * i + 1] = (s->core.h[i] >> 8) & 0xFF;
+	output[4 * i + 0] = (s->core.h[i] >> 0) & 0xFF;
+    }
+}
+
+void MD5Simple(void const *p, unsigned len, unsigned char output[16])
+{
+    struct MD5Context s;
+
+    MD5Init(&s);
+    MD5Update(&s, (unsigned char const *)p, len);
+    MD5Final(output, &s);
+}
+
+/* ----------------------------------------------------------------------
+ * The above is the MD5 algorithm itself. Now we implement the
+ * HMAC wrapper on it.
+ * 
+ * Some of these functions are exported directly, because they are
+ * useful elsewhere (SOCKS5 CHAP authentication uses HMAC-MD5).
+ */
+
+void *hmacmd5_make_context(void)
+{
+    return snewn(3, struct MD5Context);
+}
+
+void hmacmd5_free_context(void *handle)
+{
+    sfree(handle);
+}
+
+void hmacmd5_key(void *handle, void const *keyv, int len)
+{
+    struct MD5Context *keys = (struct MD5Context *)handle;
+    unsigned char foo[64];
+    unsigned char const *key = (unsigned char const *)keyv;
+    int i;
+
+    memset(foo, 0x36, 64);
+    for (i = 0; i < len && i < 64; i++)
+	foo[i] ^= key[i];
+    MD5Init(&keys[0]);
+    MD5Update(&keys[0], foo, 64);
+
+    memset(foo, 0x5C, 64);
+    for (i = 0; i < len && i < 64; i++)
+	foo[i] ^= key[i];
+    MD5Init(&keys[1]);
+    MD5Update(&keys[1], foo, 64);
+
+    smemclr(foo, 64);		       /* burn the evidence */
+}
+
+static void hmacmd5_key_16(void *handle, unsigned char *key)
+{
+    hmacmd5_key(handle, key, 16);
+}
+
+static void hmacmd5_start(void *handle)
+{
+    struct MD5Context *keys = (struct MD5Context *)handle;
+
+    keys[2] = keys[0];		      /* structure copy */
+}
+
+static void hmacmd5_bytes(void *handle, unsigned char const *blk, int len)
+{
+    struct MD5Context *keys = (struct MD5Context *)handle;
+    MD5Update(&keys[2], blk, len);
+}
+
+static void hmacmd5_genresult(void *handle, unsigned char *hmac)
+{
+    struct MD5Context *keys = (struct MD5Context *)handle;
+    struct MD5Context s;
+    unsigned char intermediate[16];
+
+    s = keys[2];		       /* structure copy */
+    MD5Final(intermediate, &s);
+    s = keys[1];		       /* structure copy */
+    MD5Update(&s, intermediate, 16);
+    MD5Final(hmac, &s);
+}
+
+static int hmacmd5_verresult(void *handle, unsigned char const *hmac)
+{
+    unsigned char correct[16];
+    hmacmd5_genresult(handle, correct);
+    return !memcmp(correct, hmac, 16);
+}
+
+static void hmacmd5_do_hmac_internal(void *handle,
+				     unsigned char const *blk, int len,
+				     unsigned char const *blk2, int len2,
+				     unsigned char *hmac)
+{
+    hmacmd5_start(handle);
+    hmacmd5_bytes(handle, blk, len);
+    if (blk2) hmacmd5_bytes(handle, blk2, len2);
+    hmacmd5_genresult(handle, hmac);
+}
+
+void hmacmd5_do_hmac(void *handle, unsigned char const *blk, int len,
+		     unsigned char *hmac)
+{
+    hmacmd5_do_hmac_internal(handle, blk, len, NULL, 0, hmac);
+}
+
+static void hmacmd5_do_hmac_ssh(void *handle, unsigned char const *blk, int len,
+				unsigned long seq, unsigned char *hmac)
+{
+    unsigned char seqbuf[16];
+
+    PUT_32BIT_MSB_FIRST(seqbuf, seq);
+    hmacmd5_do_hmac_internal(handle, seqbuf, 4, blk, len, hmac);
+}
+
+static void hmacmd5_generate(void *handle, unsigned char *blk, int len,
+			     unsigned long seq)
+{
+    hmacmd5_do_hmac_ssh(handle, blk, len, seq, blk + len);
+}
+
+static int hmacmd5_verify(void *handle, unsigned char *blk, int len,
+			  unsigned long seq)
+{
+    unsigned char correct[16];
+    hmacmd5_do_hmac_ssh(handle, blk, len, seq, correct);
+    return !memcmp(correct, blk + len, 16);
+}
+
+const struct ssh_mac ssh_hmac_md5 = {
+    hmacmd5_make_context, hmacmd5_free_context, hmacmd5_key_16,
+    hmacmd5_generate, hmacmd5_verify,
+    hmacmd5_start, hmacmd5_bytes, hmacmd5_genresult, hmacmd5_verresult,
+    "hmac-md5",
+    16,
+    "HMAC-MD5"
+};