Add fuzzer for mode unpadding, and fix bugs found thereby

Both PKCS7 and X9.23 padding modes did not examine the first byte
of the purported padding if the padding took an entire block. So
for example for a 64-bit cipher, PKCS7 would accept XX08080808080808
as a valid padding for any byte value.

1 files changed, 89 insertions, 0 deletions

diff --git a/src/tests/data/pad.vec b/src/tests/data/pad.vec
index ee24d3497..54efa4f1d 100644
--- a/src/tests/data/pad.vec
+++ b/src/tests/data/pad.vec
@@ -40,6 +40,10 @@ In  = FFFFFFFFFFFFFFFFFF
 Out = FFFFFFFFFFFFFFFFFF07070707070707
 Blocksize = 8
 
+In = 82
+Out = 8207070707070707
+Blocksize = 8
+
 [PKCS7_Invalid]
 In = FFFFFFFFFFFFFFFFFF07070706070707
 Blocksize = 8
@@ -47,6 +51,18 @@ Blocksize = 8
 In = FFFFFFFFFFFFFFFFFFFF070707070707
 Blocksize = 8
 
+In = 82040404
+Blocksize = 4
+
+In = 82050505
+Blocksize = 4
+
+In = 820606060606
+Blocksize = 6
+
+In = 8208080808080808
+Blocksize = 8
+
 [OneAndZeros]
 In  = FFFFFF
 Out = FFFFFF80000000000000000000000000
@@ -68,6 +84,14 @@ In  = FFFFFFFFFFFFFFFFFF
 Out = FFFFFFFFFFFFFFFFFF80000000000000
 Blocksize = 8
 
+In = FF
+Out = FF800000
+Blocksize = 4
+
+In = 
+Out = 80000000
+Blocksize = 4
+
 [OneAndZeros_Invalid]
 In  = FF80000000000008
 Blocksize = 8
@@ -99,6 +123,18 @@ In  = FFFFFFFFFFFFFFFFFF
 Out = FFFFFFFFFFFFFFFFFF00000000000007
 Blocksize = 8
 
+In = 7e00
+Out = 7e000002
+Blocksize = 4
+
+In = 7e
+Out = 7e000003
+Blocksize = 4
+
+In = 7e
+Out = 7e00000000000007
+Blocksize = 8
+
 [X9.23_Invalid]
 In = FFFFFFFFFFFFFFFFFF000000FFFFF00007
 Blocksize = 8
@@ -109,6 +145,21 @@ Blocksize = 8
 In = FFFFFF8000000000000000000000000D
 Blocksize = 16
 
+In = FF000004
+Blocksize = 4
+
+In = FF000005
+Blocksize = 4
+
+In = FF000006
+Blocksize = 4
+
+In = FF00000000000008
+Blocksize = 8
+
+In = 8020000000000008
+Blocksize = 8
+
 [ESP]
 In  = FFFFFF
 Out = FFFFFF0102030405060708090A0B0C0D
@@ -130,6 +181,34 @@ In  = FFFFFFFFFFFFFFFFFF
 Out = FFFFFFFFFFFFFFFFFF01020304050607
 Blocksize = 8
 
+In  = FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
+Out = FFFFFFFFFFFFFFFFFFFFFFFFFFFFFF01
+Blocksize = 8
+
+In  = FFFFFFFFFFFFFFFFFFFFFFFFFFFF
+Out = FFFFFFFFFFFFFFFFFFFFFFFFFFFF0102
+Blocksize = 8
+
+In  = FFFFFFFFFFFFFFFFFFFFFFFFFF
+Out = FFFFFFFFFFFFFFFFFFFFFFFFFF010203
+Blocksize = 8
+
+In  = FFFFFFFFFFFFFFFFFFFFFFFF
+Out = FFFFFFFFFFFFFFFFFFFFFFFF01020304
+Blocksize = 8
+
+In  = FFFFFFFFFFFFFFFFFFFFFF
+Out = FFFFFFFFFFFFFFFFFFFFFF0102030405
+Blocksize = 8
+
+In  = FFFFFFFFFFFFFFFFFFFF
+Out = FFFFFFFFFFFFFFFFFFFF010203040506
+Blocksize = 8
+
+In  = FFFFFFFFFFFFFFFFFF
+Out = FFFFFFFFFFFFFFFFFF01020304050607
+Blocksize = 8
+
 [ESP_Invalid]
 In = FF010202
 Blocksize = 4
@@ -137,6 +216,15 @@ Blocksize = 4
 In = FF010204
 Blocksize = 4
 
+In = FF000000
+Blocksize = 4
+
+In = 00000000
+Blocksize = 4
+
+In = 500ac5c5c5c5c5c5
+Blocksize = 8
+
 In = FFFFFF0102030405060708090A0B0C0F
 Blocksize = 16
 
@@ -145,3 +233,4 @@ Blocksize = 16
 
 In = FFFFFFFF0002030405060708090A0B0C
 Blocksize = 16
+