im.pidgin.pidgin: 3cec6952fcadbd73dddc4c009e798b6fb1789a5b

[evands at pidgin.im]

-----------------------------------------------------------------
Revision: 3cec6952fcadbd73dddc4c009e798b6fb1789a5b
Ancestor: 33785a8c844de496aeeed927bad8b39a6e091931
Author: evands at pidgin.im
Date: 2007-12-17T23:22:30
Branch: im.pidgin.pidgin

Modified files:
        libpurple/protocols/jabber/auth.c

ChangeLog: 

Added support for authentication via CRAM-MD5 when using jabber:iq:auth.
This, combined with 33785a8c844de496aeeed927bad8b39a6e091931, fixes connectivity with iChat Server 10.5 (a jabberd derivative with SASL support), among other servers, when libpurple is compiled with SASL support.

-------------- next part --------------
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--- libpurple/protocols/jabber/auth.c	58c06037df664e395e94097daf51b2695e251470
+++ libpurple/protocols/jabber/auth.c	a4c3673cdf3aaba368ea3fa8aaf4206452f3f7f2
@@ -570,6 +570,75 @@ static void auth_old_result_cb(JabberStr
 	}
 }
 
+/*!
+ * @brief Given the server challenge (message) and the key (password), calculate the HMAC-MD5 digest
+ *
+ * This is the crammd5 response.  Inspired by cyrus-sasl's _sasl_hmac_md5()
+ */
+static void
+auth_hmac_md5(const char *challenge, size_t challenge_len, const char *key, size_t key_len, guchar *digest)
+{
+	PurpleCipher *cipher;
+	PurpleCipherContext *context;
+	int i;
+	/* inner padding - key XORd with ipad */
+	unsigned char k_ipad[65];    
+	/* outer padding - key XORd with opad */
+	unsigned char k_opad[65];    
+
+	cipher = purple_ciphers_find_cipher("md5");
+
+	/* if key is longer than 64 bytes reset it to key=MD5(key) */
+	if (strlen(key) > 64) {
+		guchar keydigest[16];
+
+		context = purple_cipher_context_new(cipher, NULL);
+		purple_cipher_context_append(context, (const guchar *)key, strlen(key));
+		purple_cipher_context_digest(context, 16, keydigest, NULL);
+		purple_cipher_context_destroy(context);
+
+		key = (char *)keydigest;
+		key_len = 16;
+	} 
+
+	/*
+	 * the HMAC_MD5 transform looks like:
+	 *
+	 * MD5(K XOR opad, MD5(K XOR ipad, text))
+	 *
+	 * where K is an n byte key
+	 * ipad is the byte 0x36 repeated 64 times
+	 * opad is the byte 0x5c repeated 64 times
+	 * and text is the data being protected
+	 */
+
+	/* start out by storing key in pads */
+	memset(k_ipad, '\0', sizeof k_ipad);
+	memset(k_opad, '\0', sizeof k_opad);
+	memcpy(k_ipad, (void *)key, key_len);
+	memcpy(k_opad, (void *)key, key_len);
+
+	/* XOR key with ipad and opad values */
+	for (i=0; i<64; i++) {
+		k_ipad[i] ^= 0x36;
+		k_opad[i] ^= 0x5c;
+	}
+
+	/* perform inner MD5 */
+	context = purple_cipher_context_new(cipher, NULL);
+	purple_cipher_context_append(context, k_ipad, 64); /* start with inner pad */
+	purple_cipher_context_append(context, (const guchar *)challenge, challenge_len); /* then text of datagram */
+	purple_cipher_context_digest(context, 16, digest, NULL); /* finish up 1st pass */
+	purple_cipher_context_destroy(context);
+
+	/* perform outer MD5 */	
+	context = purple_cipher_context_new(cipher, NULL);
+	purple_cipher_context_append(context, k_opad, 64); /* start with outer pad */
+	purple_cipher_context_append(context, digest, 16); /* then results of 1st hash */
+	purple_cipher_context_digest(context, 16, digest, NULL); /* finish up 2nd pass */
+	purple_cipher_context_destroy(context);
+}
+
 static void auth_old_cb(JabberStream *js, xmlnode *packet, gpointer data)
 {
 	JabberIq *iq;
@@ -615,6 +684,33 @@ static void auth_old_cb(JabberStream *js
 			jabber_iq_set_callback(iq, auth_old_result_cb, NULL);
 			jabber_iq_send(iq);
 
+		} else if(js->stream_id && xmlnode_get_child(query, "crammd5")) {
+			const char *challenge;
+			guchar digest[16];
+			char h[17], *p;
+			int i;
+
+			iq = jabber_iq_new_query(js, JABBER_IQ_SET, "jabber:iq:auth");
+			query = xmlnode_get_child(iq->node, "query");
+
+			x = xmlnode_new_child(query, "username");
+			xmlnode_insert_data(x, js->user->node, -1);
+			x = xmlnode_new_child(query, "resource");
+			xmlnode_insert_data(x, js->user->resource, -1);
+
+			x = xmlnode_new_child(query, "crammd5");
+			challenge = xmlnode_get_attrib(xmlnode_get_child(query, "crammd5"), "challenge");
+			auth_hmac_md5(challenge, strlen(challenge), pw, strlen(pw), &digest);
+
+			/* Translate the digest to a hexadecimal notation */
+			p = h;
+			for(i=0; i<16; i++, p+=2)
+				snprintf(p, 3, "%02x", digest[i]);
+			xmlnode_insert_data(x, h, -1);
+
+			jabber_iq_set_callback(iq, auth_old_result_cb, NULL);
+			jabber_iq_send(iq);
+
 		} else if(xmlnode_get_child(query, "password")) {
 			if(js->gsc == NULL && !purple_account_get_bool(js->gc->account,
 						"auth_plain_in_clear", FALSE)) {