include/internal/hpke_util.h

   1 /*
   2  * Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #ifndef OSSL_INTERNAL_HPKE_UTIL_H
  11 # define OSSL_INTERNAL_HPKE_UTIL_H
  12 # pragma once
  13
  14 /* Constants from RFC 9180 Section 7.1 and 7.3 */
  15 # define OSSL_HPKE_MAX_SECRET 64
  16 # define OSSL_HPKE_MAX_PUBLIC 133
  17 # define OSSL_HPKE_MAX_PRIVATE 66
  18 # define OSSL_HPKE_MAX_KDF_INPUTLEN 64
  19
  20 /*
  21  * max length of a base-nonce (the Nn field from OSSL_HPKE_AEAD_INFO), this
  22  * is used for a local stack array size
  23  */
  24 # define OSSL_HPKE_MAX_NONCELEN 12
  25
  26 /*
  27  * @brief info about a KEM
  28  * Used to store constants from Section 7.1 "Table 2 KEM IDs"
  29  * and the bitmask for EC curves described in Section 7.1.3 DeriveKeyPair
  30  */
  31 typedef struct {
  32     uint16_t      kem_id; /* code point for key encipherment method */
  33     const char    *keytype; /* string form of algtype "EC"/"X25519"/"X448" */
  34     const char    *groupname; /* string form of EC group for NIST curves  */
  35     const char    *mdname; /* hash alg name for the HKDF */
  36     size_t        Nsecret; /* size of secrets */
  37     size_t        Nenc; /* length of encapsulated key */
  38     size_t        Npk; /* length of public key */
  39     size_t        Nsk; /* length of raw private key */
  40     uint8_t       bitmask;
  41 } OSSL_HPKE_KEM_INFO;
  42
  43 /*
  44  * @brief info about a KDF
  45  */
  46 typedef struct {
  47     uint16_t       kdf_id; /* code point for KDF */
  48     const char     *mdname; /* hash alg name for the HKDF */
  49     size_t         Nh; /* length of hash/extract output */
  50 } OSSL_HPKE_KDF_INFO;
  51
  52 /*
  53  * @brief info about an AEAD
  54  */
  55 typedef struct {
  56     uint16_t       aead_id; /* code point for aead alg */
  57     const char     *name;   /* alg name */
  58     size_t         taglen; /* aead tag len */
  59     size_t         Nk; /* size of a key for this aead */
  60     size_t         Nn; /* length of a nonce for this aead */
  61 } OSSL_HPKE_AEAD_INFO;
  62
  63 const OSSL_HPKE_KEM_INFO *ossl_HPKE_KEM_INFO_find_curve(const char *curve);
  64 const OSSL_HPKE_KEM_INFO *ossl_HPKE_KEM_INFO_find_id(uint16_t kemid);
  65 const OSSL_HPKE_KEM_INFO *ossl_HPKE_KEM_INFO_find_random(OSSL_LIB_CTX *ctx);
  66 const OSSL_HPKE_KDF_INFO *ossl_HPKE_KDF_INFO_find_id(uint16_t kdfid);
  67 const OSSL_HPKE_KDF_INFO *ossl_HPKE_KDF_INFO_find_random(OSSL_LIB_CTX *ctx);
  68 const OSSL_HPKE_AEAD_INFO *ossl_HPKE_AEAD_INFO_find_id(uint16_t aeadid);
  69 const OSSL_HPKE_AEAD_INFO *ossl_HPKE_AEAD_INFO_find_random(OSSL_LIB_CTX *ctx);
  70
  71 int ossl_hpke_kdf_extract(EVP_KDF_CTX *kctx,
  72                           unsigned char *prk, size_t prklen,
  73                           const unsigned char *salt, size_t saltlen,
  74                           const unsigned char *ikm, size_t ikmlen);
  75
  76 int ossl_hpke_kdf_expand(EVP_KDF_CTX *kctx,
  77                          unsigned char *okm, size_t okmlen,
  78                          const unsigned char *prk, size_t prklen,
  79                          const unsigned char *info, size_t infolen);
  80
  81 int ossl_hpke_labeled_extract(EVP_KDF_CTX *kctx,
  82                               unsigned char *prk, size_t prklen,
  83                               const unsigned char *salt, size_t saltlen,
  84                               const char *protocol_label,
  85                               const unsigned char *suiteid, size_t suiteidlen,
  86                               const char *label,
  87                               const unsigned char *ikm, size_t ikmlen);
  88 int ossl_hpke_labeled_expand(EVP_KDF_CTX *kctx,
  89                              unsigned char *okm, size_t okmlen,
  90                              const unsigned char *prk, size_t prklen,
  91                              const char *protocol_label,
  92                              const unsigned char *suiteid, size_t suiteidlen,
  93                              const char *label,
  94                              const unsigned char *info, size_t infolen);
  95
  96 EVP_KDF_CTX *ossl_kdf_ctx_create(const char *kdfname, const char *mdname,
  97                                  OSSL_LIB_CTX *libctx, const char *propq);
  98
  99 int ossl_hpke_str2suite(const char *suitestr, OSSL_HPKE_SUITE *suite);
 100 #endif