diff options
Diffstat (limited to 'src/passhash/passhash9/passhash9.cpp')
-rw-r--r-- | src/passhash/passhash9/passhash9.cpp | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/src/passhash/passhash9/passhash9.cpp b/src/passhash/passhash9/passhash9.cpp new file mode 100644 index 000000000..e5f379052 --- /dev/null +++ b/src/passhash/passhash9/passhash9.cpp @@ -0,0 +1,147 @@ +/* +* Passhash9 Password Hashing +* (C) 2010 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#include <botan/passhash9.h> +#include <botan/loadstor.h> +#include <botan/libstate.h> +#include <botan/pbkdf2.h> +#include <botan/b64_filt.h> +#include <botan/pipe.h> + +namespace Botan { + +namespace { + +const std::string MAGIC_PREFIX = "$9$"; + +const size_t WORKFACTOR_BYTES = 2; +const size_t ALGID_BYTES = 1; +const size_t SALT_BYTES = 12; // 96 bits of salt +const size_t PASSHASH9_PBKDF_OUTPUT_LEN = 24; // 192 bits output + +const byte PASSHASH9_DEFAULT_ALGO = 0; // HMAC(SHA-1) + +const size_t WORK_FACTOR_SCALE = 10000; + +MessageAuthenticationCode* get_pbkdf_prf(byte alg_id) + { + Algorithm_Factory& af = global_state().algorithm_factory(); + + try + { + if(alg_id == 0) + return af.make_mac("HMAC(SHA-1)"); + else if(alg_id == 1) + return af.make_mac("HMAC(SHA-256)"); + else if(alg_id == 2) + return af.make_mac("CMAC(Blowfish)"); + } + catch(Algorithm_Not_Found) {} + + return 0; + } + +} + +std::string generate_passhash9(const std::string& pass, + RandomNumberGenerator& rng, + u16bit work_factor) + { + return generate_passhash9(pass, PASSHASH9_DEFAULT_ALGO, rng, work_factor); + } + +std::string generate_passhash9(const std::string& pass, + byte alg_id, + RandomNumberGenerator& rng, + u16bit work_factor) + { + MessageAuthenticationCode* prf = get_pbkdf_prf(alg_id); + + if(!prf) + throw Invalid_Argument("Passhash9: Algorithm id " + to_string(alg_id) + + " is not defined"); + + PKCS5_PBKDF2 kdf(prf); // takes ownership of pointer + + SecureVector<byte> salt(SALT_BYTES); + rng.randomize(&salt[0], salt.size()); + + const size_t kdf_iterations = WORK_FACTOR_SCALE * work_factor; + + SecureVector<byte> pbkdf2_output = + kdf.derive_key(PASSHASH9_PBKDF_OUTPUT_LEN, + pass, + &salt[0], salt.size(), + kdf_iterations).bits_of(); + + Pipe pipe(new Base64_Encoder); + pipe.start_msg(); + pipe.write(alg_id); + pipe.write(get_byte(0, work_factor)); + pipe.write(get_byte(1, work_factor)); + pipe.write(salt); + pipe.write(pbkdf2_output); + pipe.end_msg(); + + return MAGIC_PREFIX + pipe.read_all_as_string(); + } + +bool check_passhash9(const std::string& pass, const std::string& hash) + { + const size_t BINARY_LENGTH = + ALGID_BYTES + + WORKFACTOR_BYTES + + PASSHASH9_PBKDF_OUTPUT_LEN + + SALT_BYTES; + + const size_t BASE64_LENGTH = + MAGIC_PREFIX.size() + (BINARY_LENGTH * 8) / 6; + + if(hash.size() != BASE64_LENGTH) + return false; + + for(size_t i = 0; i != MAGIC_PREFIX.size(); ++i) + if(hash[i] != MAGIC_PREFIX[i]) + return false; + + Pipe pipe(new Base64_Decoder); + pipe.start_msg(); + pipe.write(hash.c_str() + MAGIC_PREFIX.size()); + pipe.end_msg(); + + SecureVector<byte> bin = pipe.read_all(); + + if(bin.size() != BINARY_LENGTH) + return false; + + byte alg_id = bin[0]; + + const size_t kdf_iterations = + WORK_FACTOR_SCALE * load_be<u16bit>(&bin[ALGID_BYTES], 0); + + if(kdf_iterations == 0) + return false; + + MessageAuthenticationCode* pbkdf_prf = get_pbkdf_prf(alg_id); + + if(pbkdf_prf == 0) + return false; // unknown algorithm, reject + + PKCS5_PBKDF2 kdf(pbkdf_prf); // takes ownership of pointer + + SecureVector<byte> cmp = kdf.derive_key( + PASSHASH9_PBKDF_OUTPUT_LEN, + pass, + &bin[ALGID_BYTES + WORKFACTOR_BYTES], SALT_BYTES, + kdf_iterations).bits_of(); + + return same_mem(&cmp[0], + &bin[ALGID_BYTES + WORKFACTOR_BYTES + SALT_BYTES], + PASSHASH9_PBKDF_OUTPUT_LEN); + } + +} |