diff --git a/lib/msf/core/handler/reverse_http.rb b/lib/msf/core/handler/reverse_http.rb
index fe1a7d78a9..dc241353cc 100644
--- a/lib/msf/core/handler/reverse_http.rb
+++ b/lib/msf/core/handler/reverse_http.rb
@@ -36,12 +36,7 @@ module ReverseHttp
 	URI_CHECKSUM_INITW = 92
 	URI_CHECKSUM_INITJ = 88
 	URI_CHECKSUM_CONN  = 98
-
-	#
-	# Precalculated checkums as fallback
-	#
-	URI_CHECKSUM_PRECALC = ["Zjjaq", "pIlfv", "UvoxP", "sqnx9", "zvoVO", "Pajqy", "7ziuw", "vecYp", "yfHsn", "YLzzp", "cEzvr", "abmri", "9tvwr", "vTarp", "ocrgc", "mZcyl", "xfcje", "nihqa", "40F17", "zzTWt", "E3192", "wygVh", "pbqij", "rxdVs", "ajtsf", "wvuOh", "hwRwr", "pUots", "rvzoK", "vUwby", "tLzyk", "zxbuV", "niaoy", "ukxtU", "vznoU", "zuxyC", "ymvag", "Jxtxw", "404KC", "DE563", "0A7G9", "yorYv", "zzuqP", "czhwo", "949N8", "a1560", "5A2S3", "Q652A", "KR201", "uixtg", "U0K02", "4EO56", "H88H4", "5M8E6", "zudkx", "ywlsh", "luqmy", "09S4I", "L0GG0", "V916E", "KFI11", "A4BN8", "C3E2Q", "UN804", "E75HG", "622eB", "1OZ71", "kynyx", "0RE7F", "F8CR2", "1Q2EM", "txzjw", "5KD1S", "GLR40", "11BbD", "MR8B2", "X4V55", "W994P", "13d2T", "6J4AZ", "HD2EM", "766bL", "8S4MF", "MBX39", "UJI57", "eIA51", "9CZN2", "WH6AA", "a6BF9", "8B1Gg", "J2N6Z", "144Kw", "7E37v", "9I7RR", "PE6MF", "K0c4M", "LR3IF", "38p3S", "39ab3", "O0dO1", "k8H8A", "0Fz3B", "o1PE1", "h7OI0", "C1COb", "bMC6A", "8fU4C", "3IMSO", "8DbFH", "2YfG5", "bEQ1E", "MU6NI", "UCENE", "WBc0E", "T1ATX", "tBL0A", "UGPV2", "j3CLI", "7FXp1", "yN07I", "YE6k9", "KTMHE", "a7VBJ", "0Uq3R", "70Ebn", "H2PqB", "83edJ", "0w5q2", "72djI", "wA5CQ", "KF0Ix", "i7AZH", "M9tU5", "Hs3RE", "F9m1i", "7ecBF", "zS31W", "lUe21", "IvCS5", "j97nC", "CNtR5", "1g8gV", "7KwNG", "DB7hj", "ORFr7", "GCnUD", "K58jp", "5lKo8", "GPIdP", "oMIFJ", "2xYb1", "LQQPY", "FGQlN", "l5COf", "dA3Tn", "v9RWC", "VuAGI", "3vIr9", "aO3zA", "CIfx5", "Gk6Uc", "pxL94", "rKYJB", "TXAFp", "XEOGq", "aBOiJ", "qp6EJ", "YGbq4", "dR8Rh", "g0SVi", "iMr6L", "HMaIl", "yOY1Z", "UXr5Y", "PJdz6", "OQdt7", "EmZ1s", "aLIVe", "cIeo2", "mTTNP", "eVKy5", "hf5Co", "gFHzG", "VhTWN", "DvAWf", "RgFJp", "MoaXE", "Mrq4W", "hRQAp", "hAzYA", "oOSWV", "UKMme", "oP0Zw", "Mxd6b", "RsRCh", "dlk7Q", "YU6zf", "VPDjq", "ygERO", "dZZcL", "dq5qM", "LITku", "AZIxn", "bVwPL", "jGvZK", "XayKP", "rTYVY", "Vo2ph", "dwJYR", "rLTlS", "BmsfJ", "Dyv1o", "j9Hvs", "w0wVa", "iDnBy", "uKEgk", "uosI8", "2yjuO", "HiOue", "qYi4t", "7nalj", "ENekz", "rxca0", "rrePF", "cXmtD", "Xlr2y", "S7uxk", "wJqaP", "KmYyZ", "cPryG", "kYcwH", "FtDut", "xm1em", "IaymY", "fr6ew", "ixDSs", "YigPs", "PqwBs", "y2rkf", "vwaTM", "aq7wp", "fzc4z", "AyzmQ", "epJbr", "culLd", "CVtnz", "tPjPx", "nfry8", "Nkpif", "8kuzg", "zXvz8", "oVQly", "1vpnw", "jqaYh", "2tztj", "4tslx"]
-		
+	
 	#
 	# Map "random" URIs to static strings, allowing us to randomize
 	# the URI sent in the first request.
@@ -70,15 +65,11 @@ module ReverseHttp
 	# Create a URI that matches a given checksum
 	#
 	def generate_uri_checksum(sum)
-	
-		# Spend up to 1000 rounds to generate a random URI
 		0.upto(1000) do 
-			uri = Rex::Text.rand_text_alphanumeric(5)
+			uri = Rex::Text.rand_text_alphanumeric(4)
 			return uri if Rex::Text.checksum8(uri) == sum
 		end
-
-		# Otherwise return one of the pre-calculated strings
-		return URI_CHECKSUM_PRECALC[sum]		
+		raise RuntimeError, "Unable to generate a string with checksum #{sum}"
 	end
 	
 	#
diff --git a/lib/msf/core/handler/reverse_https.rb b/lib/msf/core/handler/reverse_https.rb
index 0867ef01dc..a8148a88f3 100644
--- a/lib/msf/core/handler/reverse_https.rb
+++ b/lib/msf/core/handler/reverse_https.rb
@@ -61,21 +61,18 @@ module ReverseHttps
 		
 		uri_match
 	end
-
+	
 	#
 	# Create a URI that matches a given checksum
 	#
 	def generate_uri_checksum(sum)
-		urix = nil
-		uri = Rex::Text.rand_text_alphanumeric(3)
-		("a".."z").sort_by {rand}.each do |x|
-			urix = (uri + x) if Rex::Text.checksum8(uri + x)
-			break if urix
+		0.upto(1000) do 
+			uri = Rex::Text.rand_text_alphanumeric(4)
+			return uri if Rex::Text.checksum8(uri) == sum
 		end
-		return urix if urix
 		raise RuntimeError, "Unable to generate a string with checksum #{sum}"
 	end
-
+	
 	#
 	# Initializes the HTTP SSL tunneling handler.
 	#