crypto/poly1305/poly1305_meth.c

   1 /*
   2  * Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (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 #include <openssl/evp.h>
  10 #include "internal/evp_int.h"
  11 #include "internal/poly1305.h"
  12 #include "internal/cryptlib.h"
  13 #include "poly1305_local.h"
  14
  15 /* typedef EVP_MAC_IMPL */
  16 struct evp_mac_impl_st {
  17     POLY1305 *ctx;               /* poly1305 context */
  18 };
  19
  20 static EVP_MAC_IMPL *poly1305_new(void)
  21 {
  22     EVP_MAC_IMPL *ctx;
  23
  24     if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL
  25             || (ctx->ctx = OPENSSL_zalloc(sizeof(POLY1305))) == NULL) {
  26         OPENSSL_free(ctx);
  27         return 0;
  28     }
  29     return ctx;
  30 }
  31
  32 static void poly1305_free(EVP_MAC_IMPL *ctx)
  33 {
  34     if (ctx != NULL) {
  35         OPENSSL_free(ctx->ctx);
  36         OPENSSL_free(ctx);
  37     }
  38 }
  39
  40 static int poly1305_copy(EVP_MAC_IMPL *dst, EVP_MAC_IMPL *src)
  41 {
  42     *dst->ctx = *src->ctx;
  43
  44     return 1;
  45 }
  46
  47 static size_t poly1305_size(EVP_MAC_IMPL *ctx)
  48 {
  49     return POLY1305_DIGEST_SIZE;
  50 }
  51
  52 static int poly1305_init(EVP_MAC_IMPL *ctx)
  53 {
  54     /* initialize the context in MAC_ctrl function */
  55     return 1;
  56 }
  57
  58 static int poly1305_update(EVP_MAC_IMPL *ctx, const unsigned char *data,
  59                        size_t datalen)
  60 {
  61     POLY1305 *poly_ctx = ctx->ctx;
  62
  63     /* poly1305 has nothing to return in its update function */
  64     Poly1305_Update(poly_ctx, data, datalen);
  65     return 1;
  66 }
  67
  68 static int poly1305_final(EVP_MAC_IMPL *ctx, unsigned char *out)
  69 {
  70     POLY1305 *poly_ctx = ctx->ctx;
  71
  72     Poly1305_Final(poly_ctx, out);
  73     return 1;
  74 }
  75
  76 static int poly1305_ctrl(EVP_MAC_IMPL *ctx, int cmd, va_list args)
  77 {
  78     POLY1305 *poly_ctx = ctx->ctx;
  79     unsigned char *key;
  80     size_t keylen;
  81
  82     switch (cmd) {
  83     case EVP_MAC_CTRL_SET_KEY:
  84         key = va_arg(args, unsigned char *);
  85         keylen = va_arg(args, size_t);
  86
  87         if (keylen != POLY1305_KEY_SIZE) {
  88             EVPerr(EVP_F_POLY1305_CTRL, EVP_R_INVALID_KEY_LENGTH);
  89             return 0;
  90         }
  91         Poly1305_Init(poly_ctx, key);
  92         return 1;
  93     default:
  94         return -2;
  95     }
  96     return 1;
  97 }
  98
  99 static int poly1305_ctrl_int(EVP_MAC_IMPL *ctx, int cmd, ...)
 100 {
 101     int rv;
 102     va_list args;
 103
 104     va_start(args, cmd);
 105     rv = poly1305_ctrl(ctx, cmd, args);
 106     va_end(args);
 107
 108     return rv;
 109 }
 110
 111 static int poly1305_ctrl_str_cb(void *ctx, int cmd, void *buf, size_t buflen)
 112 {
 113     return poly1305_ctrl_int(ctx, cmd, buf, buflen);
 114 }
 115
 116 static int poly1305_ctrl_str(EVP_MAC_IMPL *ctx,
 117                              const char *type, const char *value)
 118 {
 119     if (value == NULL)
 120         return 0;
 121     if (strcmp(type, "key") == 0)
 122         return EVP_str2ctrl(poly1305_ctrl_str_cb, ctx, EVP_MAC_CTRL_SET_KEY,
 123                             value);
 124     if (strcmp(type, "hexkey") == 0)
 125         return EVP_hex2ctrl(poly1305_ctrl_str_cb, ctx, EVP_MAC_CTRL_SET_KEY,
 126                             value);
 127     return -2;
 128 }
 129
 130 const EVP_MAC poly1305_meth = {
 131     EVP_MAC_POLY1305,
 132     poly1305_new,
 133     poly1305_copy,
 134     poly1305_free,
 135     poly1305_size,
 136     poly1305_init,
 137     poly1305_update,
 138     poly1305_final,
 139     poly1305_ctrl,
 140     poly1305_ctrl_str
 141 };