X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/putty/blobdiff_plain/65a22376e5875181e41108028091018cdcd4fdae..47061bb488400d53fd20deb52d51763d2caa056e:/sshmd5.c

diff --git a/sshmd5.c b/sshmd5.c
index 2b0d5f53..2fdb5900 100644
--- a/sshmd5.c
+++ b/sshmd5.c
@@ -19,17 +19,22 @@
 #define subround(f,w,x,y,z,k,s,ti) \
        w = x + rol(w + f(x,y,z) + block[k] + ti, s)
 
-void MD5_Core_Init(MD5_Core_State *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;
 }
 
-void MD5_Block(MD5_Core_State *s, uint32 *block) {
-    uint32 a,b,c,d;
+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];
+    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);
@@ -96,7 +101,10 @@ void MD5_Block(MD5_Core_State *s, uint32 *block) {
     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;
+    s->h[0] += a;
+    s->h[1] += b;
+    s->h[2] += c;
+    s->h[3] += d;
 }
 
 /* ----------------------------------------------------------------------
@@ -107,15 +115,16 @@ void MD5_Block(MD5_Core_State *s, uint32 *block) {
 
 #define BLKSIZE 64
 
-void MD5Init(struct MD5Context *s) {
+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;
+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;
@@ -126,48 +135,49 @@ void MD5Update(struct MD5Context *s, unsigned char const *p,
     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;
+    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;
+	/*
+	 * 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) {
+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;
+	pad = 56 + 64 - s->blkused;
     else
-        pad = 56 - s->blkused;
+	pad = 56 - s->blkused;
 
-    lenhi = (s->lenhi << 3) | (s->lenlo >> (32-3));
+    lenhi = (s->lenhi << 3) | (s->lenlo >> (32 - 3));
     lenlo = (s->lenlo << 3);
 
     memset(c, 0, pad);
@@ -176,93 +186,155 @@ void MD5Final(unsigned char output[16], struct MD5Context *s) {
 
     c[7] = (lenhi >> 24) & 0xFF;
     c[6] = (lenhi >> 16) & 0xFF;
-    c[5] = (lenhi >>  8) & 0xFF;
-    c[4] = (lenhi >>  0) & 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;
+    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;
+	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).
  */
 
-static struct MD5Context md5_cs_mac_s1, md5_cs_mac_s2;
-static struct MD5Context md5_sc_mac_s1, md5_sc_mac_s2;
+void *hmacmd5_make_context(void)
+{
+    return snewn(3, struct MD5Context);
+}
 
-static void md5_key(struct MD5Context *s1, struct MD5Context *s2,
-                    unsigned char *key, int len) {
+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(s1);
-    MD5Update(s1, foo, 64);
+	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(s2);
-    MD5Update(s2, foo, 64);
+	foo[i] ^= key[i];
+    MD5Init(&keys[1]);
+    MD5Update(&keys[1], foo, 64);
 
-    memset(foo, 0, 64);                /* burn the evidence */
+    smemclr(foo, 64);		       /* burn the evidence */
 }
 
-static void md5_cskey(unsigned char *key) {
-    md5_key(&md5_cs_mac_s1, &md5_cs_mac_s2, key, 16);
+static void hmacmd5_key_16(void *handle, unsigned char *key)
+{
+    hmacmd5_key(handle, key, 16);
 }
 
-static void md5_sckey(unsigned char *key) {
-    md5_key(&md5_sc_mac_s1, &md5_sc_mac_s2, key, 16);
+static void hmacmd5_start(void *handle)
+{
+    struct MD5Context *keys = (struct MD5Context *)handle;
+
+    keys[2] = keys[0];		      /* structure copy */
 }
 
-static void md5_do_hmac(struct MD5Context *s1, struct MD5Context *s2,
-                         unsigned char *blk, int len, unsigned long seq,
-                         unsigned char *hmac) {
+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];
 
-    intermediate[0] = (unsigned char)((seq >> 24) & 0xFF);
-    intermediate[1] = (unsigned char)((seq >> 16) & 0xFF);
-    intermediate[2] = (unsigned char)((seq >>  8) & 0xFF);
-    intermediate[3] = (unsigned char)((seq      ) & 0xFF);
-
-    s = *s1;                           /* structure copy */
-    MD5Update(&s, intermediate, 4);
-    MD5Update(&s, blk, len);
+    s = keys[2];		       /* structure copy */
     MD5Final(intermediate, &s);
-    s = *s2;                           /* structure copy */
+    s = keys[1];		       /* structure copy */
     MD5Update(&s, intermediate, 16);
     MD5Final(hmac, &s);
 }
 
-static void md5_generate(unsigned char *blk, int len, unsigned long seq) {
-    md5_do_hmac(&md5_cs_mac_s1, &md5_cs_mac_s2, blk, len, seq, blk+len);
+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 md5_verify(unsigned char *blk, int len, unsigned long seq) {
+static int hmacmd5_verify(void *handle, unsigned char *blk, int len,
+			  unsigned long seq)
+{
     unsigned char correct[16];
-    md5_do_hmac(&md5_sc_mac_s1, &md5_sc_mac_s2, blk, len, seq, correct);
-    return !memcmp(correct, blk+len, 16);
+    hmacmd5_do_hmac_ssh(handle, blk, len, seq, correct);
+    return !memcmp(correct, blk + len, 16);
 }
 
-const struct ssh_mac ssh_md5 = {
-    md5_cskey, md5_sckey,
-    md5_generate,
-    md5_verify,
+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
+    16,
+    "HMAC-MD5"
 };