diff options
| -rw-r--r-- | news.rst | 7 | ||||
| -rw-r--r-- | src/lib/stream/ctr/ctr.cpp | 8 | ||||
| -rw-r--r-- | src/lib/stream/ctr/ctr.h | 2 | ||||
| -rw-r--r-- | src/lib/stream/stream_cipher.cpp | 10 | ||||
| -rw-r--r-- | src/tests/data/stream/ctr.vec | 18 |
5 files changed, 39 insertions, 6 deletions
@@ -13,6 +13,13 @@ Version 2.4.0, Not Yet Released They have been changed to use the correct encoding, and a test added to ensure such errors do not recur. +* Counter mode allows setting a configurable width of the counter. + Previously it was allowed for a counter of even 8 bits wide, which + would mean the keystream would repeat after just 256 blocks. Now it + requires the width be at least 32 bits. The only way this feature + could be used was by manually constructing a ``CTR_BE`` object and + setting the second parameter to something in the range of 1 to 3. + * Add an OID for RIPEMD-160 Version 2.3.0, 2017-10-02 diff --git a/src/lib/stream/ctr/ctr.cpp b/src/lib/stream/ctr/ctr.cpp index d0b44589b..99a589bb9 100644 --- a/src/lib/stream/ctr/ctr.cpp +++ b/src/lib/stream/ctr/ctr.cpp @@ -32,7 +32,7 @@ CTR_BE::CTR_BE(BlockCipher* cipher, size_t ctr_size) : m_iv(m_cipher->block_size()), m_pad_pos(0) { - if(m_ctr_size == 0 || m_ctr_size > m_block_size) + if(m_ctr_size < 4 || m_ctr_size > m_block_size) throw Invalid_Argument("Invalid CTR-BE counter size"); } @@ -55,7 +55,11 @@ void CTR_BE::key_schedule(const uint8_t key[], size_t key_len) std::string CTR_BE::name() const { - return ("CTR-BE(" + m_cipher->name() + ")"); + if(m_ctr_size == m_block_size) + return ("CTR-BE(" + m_cipher->name() + ")"); + else + return ("CTR-BE(" + m_cipher->name() + "," + std::to_string(m_ctr_size) + ")"); + } void CTR_BE::cipher(const uint8_t in[], uint8_t out[], size_t length) diff --git a/src/lib/stream/ctr/ctr.h b/src/lib/stream/ctr/ctr.h index 3ff63b8e5..c4c598161 100644 --- a/src/lib/stream/ctr/ctr.h +++ b/src/lib/stream/ctr/ctr.h @@ -34,7 +34,7 @@ class BOTAN_PUBLIC_API(2,0) CTR_BE final : public StreamCipher std::string name() const override; CTR_BE* clone() const override - { return new CTR_BE(m_cipher->clone()); } + { return new CTR_BE(m_cipher->clone(), m_ctr_size); } void clear() override; diff --git a/src/lib/stream/stream_cipher.cpp b/src/lib/stream/stream_cipher.cpp index f33d68296..c0e75c0a8 100644 --- a/src/lib/stream/stream_cipher.cpp +++ b/src/lib/stream/stream_cipher.cpp @@ -44,12 +44,16 @@ std::unique_ptr<StreamCipher> StreamCipher::create(const std::string& algo_spec, const SCAN_Name req(algo_spec); #if defined(BOTAN_HAS_CTR_BE) - if(req.algo_name() == "CTR-BE" && req.arg_count() == 1) + if((req.algo_name() == "CTR-BE" || req.algo_name() == "CTR") && req.arg_count_between(1,2)) { if(provider.empty() || provider == "base") { - if(auto c = BlockCipher::create(req.arg(0))) - return std::unique_ptr<StreamCipher>(new CTR_BE(c.release())); + auto cipher = BlockCipher::create(req.arg(0)); + if(cipher) + { + size_t ctr_size = req.arg_as_integer(1, cipher->block_size()); + return std::unique_ptr<StreamCipher>(new CTR_BE(cipher.release(), ctr_size)); + } } } #endif diff --git a/src/tests/data/stream/ctr.vec b/src/tests/data/stream/ctr.vec index 9fddf1cfc..3eccc3cf6 100644 --- a/src/tests/data/stream/ctr.vec +++ b/src/tests/data/stream/ctr.vec @@ -280,6 +280,24 @@ Nonce = 88D9C46E992B27AE In = CD Out = 9D +[CTR-BE(AES-128,4)] +Key = 2B7E151628AED2A6ABF7158809CF4F3C +Nonce = FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF +In = 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 +Out = 8AF2860142F786F409307C1A3F7EAAAC597D5761063D8BAD232CB0136888AABB90B8CF63F44412CEEE802A522AB6566313C5E10652749056AD2F02CE3BBF5BEC + +[CTR-BE(AES-128,5)] +Key = 2B7E151628AED2A6ABF7158809CF4F3C +Nonce = FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF +In = 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 +Out = 8AF2860142F786F409307C1A3F7EAAACE0828A20E49595A19191201820125CC1B976913097C4A3245CAB186AE3B581F173DFEE01730EBB880CB63C673CBD4FC1 + +[CTR-BE(AES-128,6)] +Key = 2B7E151628AED2A6ABF7158809CF4F3C +Nonce = FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF +In = 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 +Out = 8AF2860142F786F409307C1A3F7EAAAC33E25A114853DFEA903DB7B182593CB439E12B65EBFE27B2C1557F1EAD7AB52F0D42E2BB9772747085DD8C2AF5F357BB + [CTR-BE(AES-128)] Key = 2B7E151628AED2A6ABF7158809CF4F3C Nonce = F0F1F2F3F4F5F6F7F8F9FAFBFCFDFEFF |