diff options
Diffstat (limited to 'challenge/c12.go')
| -rw-r--r-- | challenge/c12.go | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/challenge/c12.go b/challenge/c12.go index b76f28a..0308bd4 100644 --- a/challenge/c12.go +++ b/challenge/c12.go @@ -11,6 +11,18 @@ import ( func C12() { sheep := byte(65) + unknown := `Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkg +aGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBq +dXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUg +YnkK` + key, err := lib.RandomBytes(16) + if err != nil { + fmt.Printf("key generatation error: %v", err) + } + encrypt := func(in []byte) []byte { + return lib.AESEncryptECB(append(in, lib.Base64ToBytes(unknown)...), key) + } + freshSheepBytes := func(n int) []byte { in := make([]byte, n) for i := 0; i < n; i++ { @@ -22,11 +34,11 @@ func C12() { in := make([]byte, 0) in = append(in, sheep) - is := len(lib.OracleAESEncryptECB(in)) // initial size - bs := 0 // block size + is := len(encrypt(in)) // initial size + bs := 0 // block size for { in = append(in, sheep) - bs = len(lib.OracleAESEncryptECB(in)) + bs = len(encrypt(in)) if bs != is { return (bs - is) } @@ -34,13 +46,13 @@ func C12() { } findUnknownStringCharacteristics := func(blocksize int) (int, int) { in := make([]byte, 0) - c_sz := len(lib.OracleAESEncryptECB(in)) // Cipher size - nblocks := c_sz / blocksize // number of blocks + c_sz := len(encrypt(in)) // Cipher size + nblocks := c_sz / blocksize // number of blocks // Figure out ize of unknown string. for { in = append(in, sheep) - bs := len(lib.OracleAESEncryptECB(in)) + bs := len(encrypt(in)) if bs != c_sz { return nblocks, (c_sz - len(in)) } @@ -49,7 +61,7 @@ func C12() { } isOracleUsingECB := func() bool { in := lib.StrToBytes("OliverMkTukudzi OliverMkTukudzi OliverMkTukudzi") - oo := lib.OracleAESEncryptECB(in) + oo := encrypt(in) if lib.CipherUsesECB(oo) != nil { return true } @@ -61,7 +73,7 @@ func C12() { // `in` (n-1)th block that is known // `ds` deciphered unknown string decipherUnknownStringIter := func(blocksize, block, n int, in, ds []byte) ([]byte, []byte) { - oo := lib.OracleAESEncryptECB(in[0:(blocksize - n)]) + oo := encrypt(in[0:(blocksize - n)]) s := 16 * (block - 1) e := s + 16 @@ -75,7 +87,7 @@ func C12() { // Try all combinations. for i := 0; i < 256; i++ { in[15] = byte(i) - oo = lib.OracleAESEncryptECB(in) + oo = encrypt(in) if lib.BlocksEqual(nbl, oo[0:16]) { ds = append(ds, in[15]) |