diff options
author | Jack Lloyd <[email protected]> | 2016-12-08 21:37:20 -0500 |
---|---|---|
committer | Jack Lloyd <[email protected]> | 2016-12-08 21:37:20 -0500 |
commit | 3d7336406f329902cf785732c3e0fa2efb25bdd1 (patch) | |
tree | d3ee3c9b3f037777540926bc335f76eb95748e3b /src/lib/pk_pad | |
parent | 578d4208f7410e110a084fbcfaa30eea1d057f9e (diff) | |
parent | 63a1c6cd6b40868a5234428830fee0d63fd51ba2 (diff) |
Merge GH #759 Add ISO 9796-2 signature schemes
Diffstat (limited to 'src/lib/pk_pad')
-rw-r--r-- | src/lib/pk_pad/emsa.cpp | 55 | ||||
-rw-r--r-- | src/lib/pk_pad/iso9796/info.txt | 7 | ||||
-rw-r--r-- | src/lib/pk_pad/iso9796/iso9796.cpp | 270 | ||||
-rw-r--r-- | src/lib/pk_pad/iso9796/iso9796.h | 94 |
4 files changed, 414 insertions, 12 deletions
diff --git a/src/lib/pk_pad/emsa.cpp b/src/lib/pk_pad/emsa.cpp index 66e58fb0d..3851f85a7 100644 --- a/src/lib/pk_pad/emsa.cpp +++ b/src/lib/pk_pad/emsa.cpp @@ -8,23 +8,27 @@ #include <botan/scan_name.h> #if defined(BOTAN_HAS_EMSA1) - #include <botan/emsa1.h> + #include <botan/emsa1.h> #endif #if defined(BOTAN_HAS_EMSA_X931) - #include <botan/emsa_x931.h> + #include <botan/emsa_x931.h> #endif #if defined(BOTAN_HAS_EMSA_PKCS1) - #include <botan/emsa_pkcs1.h> + #include <botan/emsa_pkcs1.h> #endif #if defined(BOTAN_HAS_EMSA_PSSR) - #include <botan/pssr.h> + #include <botan/pssr.h> #endif #if defined(BOTAN_HAS_EMSA_RAW) - #include <botan/emsa_raw.h> + #include <botan/emsa_raw.h> +#endif + +#if defined(BOTAN_HAS_ISO_9796) + #include <botan/iso9796.h> #endif namespace Botan { @@ -45,8 +49,8 @@ EMSA* get_emsa(const std::string& algo_spec) #if defined(BOTAN_HAS_EMSA_PKCS1) if(req.algo_name() == "EMSA_PKCS1" || - req.algo_name() == "EMSA-PKCS1-v1_5" || - req.algo_name() == "EMSA3") + req.algo_name() == "EMSA-PKCS1-v1_5" || + req.algo_name() == "EMSA3") { if(req.arg_count() == 1) { @@ -67,9 +71,9 @@ EMSA* get_emsa(const std::string& algo_spec) #if defined(BOTAN_HAS_EMSA_PSSR) if(req.algo_name() == "PSSR" || - req.algo_name() == "EMSA-PSS" || - req.algo_name() == "PSS-MGF1" || - req.algo_name() == "EMSA4") + req.algo_name() == "EMSA-PSS" || + req.algo_name() == "PSS-MGF1" || + req.algo_name() == "EMSA4") { if(req.arg_count_between(1, 3)) { @@ -85,10 +89,37 @@ EMSA* get_emsa(const std::string& algo_spec) } #endif +#if defined(BOTAN_HAS_ISO_9796) + if(req.algo_name() == "ISO_9796_DS2") + { + if(req.arg_count_between(1, 3)) + { + if(auto h = HashFunction::create(req.arg(0))) + { + const size_t salt_size = req.arg_as_integer(2, h->output_length()); + const bool implicit = req.arg(1, "exp") == "imp"; + return new ISO_9796_DS2(h.release(), implicit, salt_size); + } + } + } + //ISO-9796-2 DS 3 is deterministic and DS2 without a salt + if(req.algo_name() == "ISO_9796_DS3") + { + if(req.arg_count_between(1, 2)) + { + if(auto h = HashFunction::create(req.arg(0))) + { + const bool implicit = req.arg(1, "exp") == "imp"; + return new ISO_9796_DS3(h.release(), implicit); + } + } + } +#endif + #if defined(BOTAN_HAS_EMSA_X931) if(req.algo_name() == "EMSA_X931" || - req.algo_name() == "EMSA2" || - req.algo_name() == "X9.31") + req.algo_name() == "EMSA2" || + req.algo_name() == "X9.31") { if(req.arg_count() == 1) { diff --git a/src/lib/pk_pad/iso9796/info.txt b/src/lib/pk_pad/iso9796/info.txt new file mode 100644 index 000000000..3458ece45 --- /dev/null +++ b/src/lib/pk_pad/iso9796/info.txt @@ -0,0 +1,7 @@ +define ISO_9796 20161121 + +<requires> +mgf1 +hash_id +</requires> + diff --git a/src/lib/pk_pad/iso9796/iso9796.cpp b/src/lib/pk_pad/iso9796/iso9796.cpp new file mode 100644 index 000000000..db79661e3 --- /dev/null +++ b/src/lib/pk_pad/iso9796/iso9796.cpp @@ -0,0 +1,270 @@ +/* + * ISO-9796-2 - Digital signature schemes giving message recovery schemes 2 and 3 + * (C) 2016 Tobias Niemann, Hackmanit GmbH + * + * Botan is released under the Simplified BSD License (see license.txt) + */ + +#include <botan/iso9796.h> +#include <botan/mgf1.h> +#include <botan/internal/bit_ops.h> +#include <botan/hash_id.h> + +namespace Botan { + +namespace { + +secure_vector<byte> iso9796_encoding(const secure_vector<byte>& msg, + size_t output_bits, std::unique_ptr<HashFunction>& hash, size_t SALT_SIZE, bool implicit, RandomNumberGenerator& rng) + { + const size_t output_length = (output_bits + 7) / 8; + + //set trailer length + size_t tLength = 1; + if(!implicit) + { + tLength = 2; + } + const size_t HASH_SIZE = hash->output_length(); + + if(output_length <= HASH_SIZE + SALT_SIZE + tLength) + { + throw Encoding_Error("ISO9796-2::encoding_of: Output length is too small"); + } + + //calculate message capacity + const size_t capacity = output_length + - HASH_SIZE - SALT_SIZE - tLength - 1; + + //msg1 is the recoverable and msg2 the unrecoverable message part. + secure_vector<byte> msg1; + secure_vector<byte> msg2; + if(msg.size() > capacity) + { + msg1 = secure_vector<byte> (msg.begin(), msg.begin() + capacity); + msg2 = secure_vector<byte> (msg.begin() + capacity, msg.end()); + hash->update(msg2); + } + else + { + msg1 = msg; + } + msg2 = hash->final(); + + //compute H(C||msg1 ||H(msg2)||S) + uint64_t msgLength = msg1.size(); + secure_vector<byte> salt = rng.random_vec(SALT_SIZE); + hash->update_be(msgLength * 8); + hash->update(msg1); + hash->update(msg2); + hash->update(salt); + secure_vector<byte> H = hash->final(); + + secure_vector<byte> EM(output_length); + + //compute message offset. + size_t offset = output_length - HASH_SIZE - SALT_SIZE - tLength + - msgLength - 1; + + //insert message border (0x01), msg1 and salt into the output buffer + EM[offset] = 0x01; + buffer_insert(EM, offset + 1, msg1); + buffer_insert(EM, offset + 1 + msgLength, salt); + + //apply mask + mgf1_mask(*hash, H.data(), HASH_SIZE, EM.data(), + output_length - HASH_SIZE - tLength); + buffer_insert(EM, output_length - HASH_SIZE - tLength, H); + //set implicit/ISO trailer + if(!implicit) + { + byte hash_id = ieee1363_hash_id(hash->name()); + if(!hash_id) + { + throw Encoding_Error("ISO9796-2::encoding_of: no hash identifier for " + hash->name()); + } + EM[output_length - 1] = 0xCC; + EM[output_length - 2] = hash_id; + + } + else + { + EM[output_length - 1] = 0xBC; + } + //clear the leftmost bit (confer bouncy castle) + EM[0] &= 0x7F; + + return EM; + } + +bool iso9796_verification(const secure_vector<byte>& const_coded, + const secure_vector<byte>& raw, size_t key_bits, std::unique_ptr<HashFunction>& hash, size_t SALT_SIZE) + { + const size_t HASH_SIZE = hash->output_length(); + const size_t KEY_BYTES = (key_bits + 7) / 8; + + if(const_coded.size() != KEY_BYTES) + { + return false; + } + //get trailer length + size_t tLength; + if(const_coded[const_coded.size() - 1] == 0xBC) + { + tLength = 1; + } + else + { + byte hash_id = ieee1363_hash_id(hash->name()); + if((!const_coded[const_coded.size() - 2]) || (const_coded[const_coded.size() - 2] != hash_id) || + (const_coded[const_coded.size() - 1] != 0xCC)) + { + return false; //in case of wrong ISO trailer. + } + tLength = 2; + } + + secure_vector<byte> coded = const_coded; + + //remove mask + byte* DB = coded.data(); + const size_t DB_size = coded.size() - HASH_SIZE - tLength; + + const byte* H = &coded[DB_size]; + + mgf1_mask(*hash, H, HASH_SIZE, DB, DB_size); + //clear the leftmost bit (confer bouncy castle) + DB[0] &= 0x7F; + + //recover msg1 and salt + size_t msg1_offset = 0; + for(size_t j = 0; j != DB_size; ++j) + { + if(DB[j] == 0x01) + { + msg1_offset = j + 1; + break; + } + } + if(msg1_offset == 0) + { + return false; + } + secure_vector<byte> msg1(coded.begin() + msg1_offset, + coded.end() - tLength - HASH_SIZE - SALT_SIZE); + secure_vector<byte> salt(coded.begin() + msg1_offset + msg1.size(), + coded.end() - tLength - HASH_SIZE); + + //compute H2(C||msg1||H(msg2)||S*). * indicates a recovered value + const size_t capacity = (key_bits - 2 + 7) / 8 - HASH_SIZE + - SALT_SIZE - tLength - 1; + secure_vector<byte> msg1raw; + secure_vector<byte> msg2; + if(raw.size() > capacity) + { + msg1raw = secure_vector<byte> (raw.begin(), raw.begin() + capacity); + msg2 = secure_vector<byte> (raw.begin() + capacity, raw.end()); + hash->update(msg2); + } + else + { + msg1raw = raw; + } + msg2 = hash->final(); + + uint64_t msg1rawLength = msg1raw.size(); + hash->update_be(msg1rawLength * 8); + hash->update(msg1raw); + hash->update(msg2); + hash->update(salt); + secure_vector<byte> H3 = hash->final(); + + //compute H3(C*||msg1*||H(msg2)||S*) * indicates a recovered value + uint64_t msgLength = msg1.size(); + hash->update_be(msgLength * 8); + hash->update(msg1); + hash->update(msg2); + hash->update(salt); + secure_vector<byte> H2 = hash->final(); + + //check if H3 == H2 + return same_mem(H3.data(), H2.data(), HASH_SIZE); + } + +} +/* + * ISO-9796-2 signature scheme 2 + * DS 2 is probabilistic + */ +void ISO_9796_DS2::update(const byte input[], size_t length) + { + //need to buffer message completely, before digest + m_msg_buffer.insert(m_msg_buffer.end(), input, input+length); + } + +/* + * Return the raw (unencoded) data + */ +secure_vector<byte> ISO_9796_DS2::raw_data() + { + secure_vector<byte> retbuffer = m_msg_buffer; + m_msg_buffer.clear(); + return retbuffer; + } + +/* + * ISO-9796-2 scheme 2 encode operation + */ +secure_vector<byte> ISO_9796_DS2::encoding_of(const secure_vector<byte>& msg, + size_t output_bits, RandomNumberGenerator& rng) + { + return iso9796_encoding(msg, output_bits, m_hash, m_SALT_SIZE, m_implicit, rng); + } + +/* + * ISO-9796-2 scheme 2 verify operation + */ +bool ISO_9796_DS2::verify(const secure_vector<byte>& const_coded, + const secure_vector<byte>& raw, size_t key_bits) + { + return iso9796_verification(const_coded,raw,key_bits,m_hash,m_SALT_SIZE); + } + +/* + * ISO-9796-2 signature scheme 3 + * DS 3 is deterministic and equals DS2 without salt + */ +void ISO_9796_DS3::update(const byte input[], size_t length) + { + //need to buffer message completely, before digest + m_msg_buffer.insert(m_msg_buffer.end(), input, input+length); + } + +/* + * Return the raw (unencoded) data + */ +secure_vector<byte> ISO_9796_DS3::raw_data() + { + secure_vector<byte> retbuffer = m_msg_buffer; + m_msg_buffer.clear(); + return retbuffer; + } + +/* + * ISO-9796-2 scheme 3 encode operation + */ +secure_vector<byte> ISO_9796_DS3::encoding_of(const secure_vector<byte>& msg, + size_t output_bits, RandomNumberGenerator& rng) + { + return iso9796_encoding(msg, output_bits, m_hash, 0, m_implicit, rng); + } + +/* + * ISO-9796-2 scheme 3 verify operation + */ +bool ISO_9796_DS3::verify(const secure_vector<byte>& const_coded, + const secure_vector<byte>& raw, size_t key_bits) + { + return iso9796_verification(const_coded, raw, key_bits, m_hash, 0); + } +}
\ No newline at end of file diff --git a/src/lib/pk_pad/iso9796/iso9796.h b/src/lib/pk_pad/iso9796/iso9796.h new file mode 100644 index 000000000..da3fff055 --- /dev/null +++ b/src/lib/pk_pad/iso9796/iso9796.h @@ -0,0 +1,94 @@ +/* + * ISO-9796-2 - Digital signature schemes giving message recovery schemes 2 and 3 + * (C) 2016 Tobias Niemann, Hackmanit GmbH + * + * Botan is released under the Simplified BSD License (see license.txt) + */ + +#ifndef BOTAN_ISO9796_H__ +#define BOTAN_ISO9796_H__ + +#include <botan/emsa.h> +#include <botan/hash.h> + +namespace Botan { + +/** +* ISO-9796-2 - Digital signature scheme 2 (probabilistic) +*/ +class BOTAN_DLL ISO_9796_DS2 final : public EMSA + { + public: + /** + * @param hash function to use + * @param use implicit ISO trailer + */ + explicit ISO_9796_DS2(HashFunction* hash, bool implicit = false) : m_hash(hash), m_implicit(implicit), + m_SALT_SIZE(hash->output_length()) {} + + /** + * @param hash function to use + * @param whether or not the trailer is implicit + * @param size of the salt to use in bytes + */ + ISO_9796_DS2(HashFunction* hash, bool implicit, size_t salt_size) : m_hash(hash), m_implicit(implicit), + m_SALT_SIZE(salt_size) {} + + EMSA* clone() override + {return new ISO_9796_DS2(m_hash->clone(), m_implicit, m_SALT_SIZE);} + private: + void update(const byte input[], size_t length) override; + + secure_vector<byte> raw_data() override; + + secure_vector<byte> encoding_of(const secure_vector<byte>& msg, + size_t output_bits, + RandomNumberGenerator& rng) override; + + bool verify(const secure_vector<byte>& coded, + const secure_vector<byte>& raw, + size_t key_bits) override; + + std::unique_ptr<HashFunction> m_hash; + bool m_implicit; + size_t m_SALT_SIZE; + secure_vector<byte> m_msg_buffer; + }; + +/** +* ISO-9796-2 - Digital signature scheme 3 (deterministic) +*/ +class BOTAN_DLL ISO_9796_DS3 final : public EMSA + { + public: + /** + * @param hash function to use + * @param whether or not the trailer is implicit + */ + ISO_9796_DS3(HashFunction* hash, bool implicit = false) : m_hash(hash), m_implicit(implicit) + {} + + EMSA* clone() override + {return new ISO_9796_DS3(m_hash->clone(), m_implicit);} + private: + void update(const byte input[], size_t length) override; + + secure_vector<byte> raw_data() override; + + secure_vector<byte> encoding_of(const secure_vector<byte>& msg, + size_t output_bits, + RandomNumberGenerator& rng) override; + + bool verify(const secure_vector<byte>& coded, + const secure_vector<byte>& raw, + size_t key_bits) override; + + std::unique_ptr<HashFunction> m_hash; + bool m_implicit; + secure_vector<byte> m_msg_buffer; + }; + +} + +#endif + |