diff options
author | Krzysztof Kwiatkowski <kris@amongbytes.com> | 2017-04-30 15:48:47 +0100 |
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committer | Krzysztof Kwiatkowski <kris@amongbytes.com> | 2017-05-03 00:44:28 +0100 |
commit | 576ada6d0b1ae20b781d487ba9bbeaadef17b202 (patch) | |
tree | ef0122d482dd6bbb36fe6a5fa82138bc6599dcaf /src/lib/kdf | |
parent | 29cc6bebe132a34f882d450b35a69bf71bb3e27b (diff) |
Adds KDF based on SP 800-56A. Currently it is revision 1 (alternative 1). It should be extended to revision 2.
Diffstat (limited to 'src/lib/kdf')
-rw-r--r-- | src/lib/kdf/kdf.cpp | 14 | ||||
-rw-r--r-- | src/lib/kdf/sp800_56a/info.txt | 7 | ||||
-rw-r--r-- | src/lib/kdf/sp800_56a/sp800_56a.cpp | 51 | ||||
-rw-r--r-- | src/lib/kdf/sp800_56a/sp800_56a.h | 58 |
4 files changed, 130 insertions, 0 deletions
diff --git a/src/lib/kdf/kdf.cpp b/src/lib/kdf/kdf.cpp index 0e9d840c1..122719f6d 100644 --- a/src/lib/kdf/kdf.cpp +++ b/src/lib/kdf/kdf.cpp @@ -42,6 +42,10 @@ #include <botan/sp800_108.h> #endif +#if defined(BOTAN_HAS_SP800_56A) +#include <botan/sp800_56a.h> +#endif + #if defined(BOTAN_HAS_SP800_56C) #include <botan/sp800_56c.h> #endif @@ -185,6 +189,16 @@ std::unique_ptr<KDF> KDF::create(const std::string& algo_spec, } #endif +#if defined(BOTAN_HAS_SP800_56A) + if(req.algo_name() == "SP800-56A" && req.arg_count() == 1) + { + if(auto hash = HashFunction::create(req.arg(0))) + { + return std::unique_ptr<KDF>(new SP800_56A(hash.release())); + } + } +#endif + #if defined(BOTAN_HAS_SP800_56C) if(req.algo_name() == "SP800-56C" && req.arg_count() == 1) { diff --git a/src/lib/kdf/sp800_56a/info.txt b/src/lib/kdf/sp800_56a/info.txt new file mode 100644 index 000000000..d8ef51673 --- /dev/null +++ b/src/lib/kdf/sp800_56a/info.txt @@ -0,0 +1,7 @@ +<defines> +SP800_56A -> 20170501 +</defines> + +<requires> +hmac +</requires> diff --git a/src/lib/kdf/sp800_56a/sp800_56a.cpp b/src/lib/kdf/sp800_56a/sp800_56a.cpp new file mode 100644 index 000000000..9f5c1b1c5 --- /dev/null +++ b/src/lib/kdf/sp800_56a/sp800_56a.cpp @@ -0,0 +1,51 @@ +/* +* KDF defined in NIST SP 800-56a (Approved Alternative 1) +* (C) 2017 Krzysztof Kwiatkowski +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#include <botan/sp800_56a.h> +#include <botan/hmac.h> +#include <botan/assert.h> +#include <botan/mem_ops.h> + +namespace Botan { + +static const size_t MAX_REPS = (2ULL << 32); + +size_t SP800_56A::kdf( uint8_t key[], size_t key_len, + const uint8_t secret[], size_t secret_len, + const uint8_t salt[], size_t salt_len, + const uint8_t label[], size_t label_len) const +{ + // Salt is not used by this algorithm + BOTAN_UNUSED(salt, salt_len); + + secure_vector<uint8_t> h; + const size_t digest_len = m_hash->output_length(); + + size_t reps = key_len / digest_len + !!(key_len % digest_len); + if (reps >= MAX_REPS) { + // See SP-800-56A, point 5.8.1 + throw Invalid_Argument( + "key_len / digest output size " + "can't be bigger than 2^32 - 1"); + } + + uint32_t counter = 1; + for(size_t i = 0; i < reps; i++) { + m_hash->update_be(counter++); + m_hash->update(secret, secret_len); + m_hash->update(label, label_len); + m_hash->final(h); + + const size_t offset = digest_len * i; + const size_t len = std::min(h.size(), key_len - offset); + copy_mem(&key[offset], h.data(), len); + } + + return key_len; +} + +} diff --git a/src/lib/kdf/sp800_56a/sp800_56a.h b/src/lib/kdf/sp800_56a/sp800_56a.h new file mode 100644 index 000000000..822f5ca1a --- /dev/null +++ b/src/lib/kdf/sp800_56a/sp800_56a.h @@ -0,0 +1,58 @@ +/* +* KDF defined in NIST SP 800-56a (Approved Alternative 1) +* (C) 2016 Krzysztof Kwiatkowski +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#ifndef BOTAN_SP800_56A_H__ +#define BOTAN_SP800_56A_H__ + +#include <botan/kdf.h> +#include <botan/hash.h> + +namespace Botan { + +/** + * NIST SP 800-56A KDF + */ +class BOTAN_DLL SP800_56A final : public KDF + { + public: + std::string name() const override { return "SP800-56A(" + m_hash->name() + ")"; } + + KDF* clone() const override { return new SP800_56A(m_hash->clone()); } + + /** + * Derive a key using the SP800-56A KDF. + * + * The implementation hard codes the context value for the + * expansion step to the empty string. + * + * @param key derived keying material K_M + * @param key_len the desired output length in bytes + * @param secret shared secret Z + * @param secret_len size of Z in bytes + * @param salt salt not used by an algorithm + * @param salt_len not used by an algorithm + * @param label label for the expansion step + * @param label_len size of label in bytes + * + * @throws Invalid_Argument key_len > 2^32 + */ + size_t kdf(uint8_t key[], size_t key_len, + const uint8_t secret[], size_t secret_len, + const uint8_t salt[], size_t salt_len, + const uint8_t label[], size_t label_len) const override; + + /** + * @param hash HASH algorithm used + */ + explicit SP800_56A(HashFunction* hash) : m_hash(hash) {} + private: + std::unique_ptr<HashFunction> m_hash; + }; +} + +#endif + |