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Diffstat (limited to '')
-rw-r--r-- | src/lib/pkcs5.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/src/lib/pkcs5.c b/src/lib/pkcs5.c new file mode 100644 index 0000000..e035d47 --- /dev/null +++ b/src/lib/pkcs5.c @@ -0,0 +1,97 @@ +/* Copyright (c) 2016-2018 Dovecot authors, see the included COPYING file */ + +#include "lib.h" +#include "buffer.h" +#include "hash-method.h" +#include "hmac.h" +#include "pkcs5.h" + +#include <stdint.h> +#include <arpa/inet.h> + +static +int pkcs5_pbkdf1(const struct hash_method *hash, + const unsigned char *password, size_t password_len, + const unsigned char *salt, size_t salt_len, + unsigned int iter, uint32_t length, + buffer_t *result) +{ + if (length < 1 || + length > hash->digest_size) return -1; + if (iter < 1) return -1; + + unsigned char dk[hash->digest_size]; + unsigned char ctx[hash->context_size]; + + hash->init(ctx); + hash->loop(ctx, password, password_len); + hash->loop(ctx, salt, salt_len); + hash->result(ctx, dk); + length--; + + for(;length>0;length--) { + hash->init(ctx); + hash->loop(ctx, dk, hash->digest_size); + hash->result(ctx, dk); + } + + buffer_append(result, dk, hash->digest_size); + + return 0; +} + +static +int pkcs5_pbkdf2(const struct hash_method *hash, + const unsigned char *password, size_t password_len, + const unsigned char *salt, size_t salt_len, + unsigned int iter, uint32_t length, + buffer_t *result) +{ + if (length < 1 || iter < 1) return -1; + + size_t l = (length + hash->digest_size - 1)/hash->digest_size; /* same as ceil(length/hash->digest_size) */ + unsigned char dk[l * hash->digest_size]; + unsigned char *block; + struct hmac_context hctx; + unsigned int c,i,t; + unsigned char U_c[hash->digest_size]; + + for(t = 0; t < l; t++) { + block = &(dk[t*hash->digest_size]); + /* U_1 = PRF(Password, Salt|| INT_BE32(Block_Number)) */ + c = htonl(t+1); + hmac_init(&hctx, password, password_len, hash); + hmac_update(&hctx, salt, salt_len); + hmac_update(&hctx, &c, sizeof(c)); + hmac_final(&hctx, U_c); + /* block = U_1 ^ .. ^ U_iter */ + memcpy(block, U_c, hash->digest_size); + /* U_c = PRF(Password, U_c-1) */ + for(c = 1; c < iter; c++) { + hmac_init(&hctx, password, password_len, hash); + hmac_update(&hctx, U_c, hash->digest_size); + hmac_final(&hctx, U_c); + for(i = 0; i < hash->digest_size; i++) + block[i] ^= U_c[i]; + } + } + + buffer_append(result, dk, length); + + return 0; +} + +int pkcs5_pbkdf(enum pkcs5_pbkdf_mode mode, const struct hash_method *hash, + const unsigned char *password, size_t password_len, + const unsigned char *salt, size_t salt_len, + unsigned int iterations, uint32_t dk_len, + buffer_t *result) +{ + if (mode == PKCS5_PBKDF1) + return pkcs5_pbkdf1(hash,password,password_len, + salt,salt_len,iterations,dk_len,result); + else if (mode == PKCS5_PBKDF2) + return pkcs5_pbkdf2(hash,password,password_len, + salt,salt_len,iterations,dk_len,result); + i_unreached(); +} |