1 | /*
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2 | * Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
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3 | *
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4 | * Licensed under the OpenSSL license (the "License"). You may not use
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5 | * this file except in compliance with the License. You can obtain a copy
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6 | * in the file LICENSE in the source distribution or at
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7 | * https://www.openssl.org/source/license.html
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8 | */
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9 |
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10 | #include <stdlib.h>
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11 | #include "ssl_local.h"
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12 | #include "internal/cryptlib.h"
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13 | #include <openssl/evp.h>
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14 | #include <openssl/kdf.h>
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15 |
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16 | #define TLS13_MAX_LABEL_LEN 249
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17 |
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18 | /* Always filled with zeros */
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19 | static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
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20 |
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21 | /*
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22 | * Given a |secret|; a |label| of length |labellen|; and |data| of length
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23 | * |datalen| (e.g. typically a hash of the handshake messages), derive a new
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24 | * secret |outlen| bytes long and store it in the location pointed to be |out|.
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25 | * The |data| value may be zero length. Any errors will be treated as fatal if
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26 | * |fatal| is set. Returns 1 on success 0 on failure.
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27 | */
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28 | int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
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29 | const unsigned char *label, size_t labellen,
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30 | const unsigned char *data, size_t datalen,
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31 | unsigned char *out, size_t outlen, int fatal)
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32 | {
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33 | #ifdef CHARSET_EBCDIC
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34 | static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 };
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35 | #else
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36 | static const unsigned char label_prefix[] = "tls13 ";
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37 | #endif
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38 | EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
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39 | int ret;
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40 | size_t hkdflabellen;
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41 | size_t hashlen;
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42 | /*
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43 | * 2 bytes for length of derived secret + 1 byte for length of combined
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44 | * prefix and label + bytes for the label itself + 1 byte length of hash
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45 | * + bytes for the hash itself
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46 | */
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47 | unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t)
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48 | + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN
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49 | + 1 + EVP_MAX_MD_SIZE];
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50 | WPACKET pkt;
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51 |
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52 | if (pctx == NULL)
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53 | return 0;
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54 |
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55 | if (labellen > TLS13_MAX_LABEL_LEN) {
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56 | if (fatal) {
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57 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
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58 | ERR_R_INTERNAL_ERROR);
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59 | } else {
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60 | /*
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61 | * Probably we have been called from SSL_export_keying_material(),
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62 | * or SSL_export_keying_material_early().
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63 | */
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64 | SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
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65 | }
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66 | EVP_PKEY_CTX_free(pctx);
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67 | return 0;
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68 | }
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69 |
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70 | hashlen = EVP_MD_size(md);
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71 |
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72 | if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
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73 | || !WPACKET_put_bytes_u16(&pkt, outlen)
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74 | || !WPACKET_start_sub_packet_u8(&pkt)
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75 | || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
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76 | || !WPACKET_memcpy(&pkt, label, labellen)
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77 | || !WPACKET_close(&pkt)
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78 | || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
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79 | || !WPACKET_get_total_written(&pkt, &hkdflabellen)
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80 | || !WPACKET_finish(&pkt)) {
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81 | EVP_PKEY_CTX_free(pctx);
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82 | WPACKET_cleanup(&pkt);
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83 | if (fatal)
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84 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
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85 | ERR_R_INTERNAL_ERROR);
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86 | else
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87 | SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
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88 | return 0;
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89 | }
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90 |
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91 | ret = EVP_PKEY_derive_init(pctx) <= 0
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92 | || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY)
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93 | <= 0
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94 | || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
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95 | || EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, hashlen) <= 0
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96 | || EVP_PKEY_CTX_add1_hkdf_info(pctx, hkdflabel, hkdflabellen) <= 0
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97 | || EVP_PKEY_derive(pctx, out, &outlen) <= 0;
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98 |
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99 | EVP_PKEY_CTX_free(pctx);
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100 |
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101 | if (ret != 0) {
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102 | if (fatal)
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103 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
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104 | ERR_R_INTERNAL_ERROR);
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105 | else
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106 | SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
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107 | }
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108 |
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109 | return ret == 0;
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110 | }
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111 |
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112 | /*
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113 | * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
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114 | * success 0 on failure.
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115 | */
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116 | int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
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117 | unsigned char *key, size_t keylen)
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118 | {
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119 | #ifdef CHARSET_EBCDIC
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120 | static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 };
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121 | #else
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122 | static const unsigned char keylabel[] = "key";
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123 | #endif
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124 |
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125 | return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
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126 | NULL, 0, key, keylen, 1);
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127 | }
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128 |
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129 | /*
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130 | * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
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131 | * success 0 on failure.
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132 | */
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133 | int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
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134 | unsigned char *iv, size_t ivlen)
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135 | {
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136 | #ifdef CHARSET_EBCDIC
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137 | static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 };
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138 | #else
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139 | static const unsigned char ivlabel[] = "iv";
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140 | #endif
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141 |
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142 | return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
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143 | NULL, 0, iv, ivlen, 1);
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144 | }
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145 |
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146 | int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
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147 | const unsigned char *secret,
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148 | unsigned char *fin, size_t finlen)
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149 | {
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150 | #ifdef CHARSET_EBCDIC
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151 | static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 };
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152 | #else
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153 | static const unsigned char finishedlabel[] = "finished";
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154 | #endif
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155 |
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156 | return tls13_hkdf_expand(s, md, secret, finishedlabel,
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157 | sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
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158 | }
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159 |
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160 | /*
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161 | * Given the previous secret |prevsecret| and a new input secret |insecret| of
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162 | * length |insecretlen|, generate a new secret and store it in the location
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163 | * pointed to by |outsecret|. Returns 1 on success 0 on failure.
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164 | */
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165 | int tls13_generate_secret(SSL *s, const EVP_MD *md,
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166 | const unsigned char *prevsecret,
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167 | const unsigned char *insecret,
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168 | size_t insecretlen,
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169 | unsigned char *outsecret)
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170 | {
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171 | size_t mdlen, prevsecretlen;
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172 | int mdleni;
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173 | int ret;
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174 | EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
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175 | #ifdef CHARSET_EBCDIC
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176 | static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 };
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177 | #else
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178 | static const char derived_secret_label[] = "derived";
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179 | #endif
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180 | unsigned char preextractsec[EVP_MAX_MD_SIZE];
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181 |
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182 | if (pctx == NULL) {
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183 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
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184 | ERR_R_INTERNAL_ERROR);
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185 | return 0;
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186 | }
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187 |
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188 | mdleni = EVP_MD_size(md);
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189 | /* Ensure cast to size_t is safe */
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190 | if (!ossl_assert(mdleni >= 0)) {
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191 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
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192 | ERR_R_INTERNAL_ERROR);
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193 | return 0;
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194 | }
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195 | mdlen = (size_t)mdleni;
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196 |
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197 | if (insecret == NULL) {
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198 | insecret = default_zeros;
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199 | insecretlen = mdlen;
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200 | }
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201 | if (prevsecret == NULL) {
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202 | prevsecret = default_zeros;
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203 | prevsecretlen = 0;
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204 | } else {
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205 | EVP_MD_CTX *mctx = EVP_MD_CTX_new();
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206 | unsigned char hash[EVP_MAX_MD_SIZE];
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207 |
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208 | /* The pre-extract derive step uses a hash of no messages */
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209 | if (mctx == NULL
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210 | || EVP_DigestInit_ex(mctx, md, NULL) <= 0
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211 | || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
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212 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
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213 | ERR_R_INTERNAL_ERROR);
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214 | EVP_MD_CTX_free(mctx);
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215 | EVP_PKEY_CTX_free(pctx);
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216 | return 0;
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217 | }
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218 | EVP_MD_CTX_free(mctx);
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219 |
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220 | /* Generate the pre-extract secret */
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221 | if (!tls13_hkdf_expand(s, md, prevsecret,
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222 | (unsigned char *)derived_secret_label,
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223 | sizeof(derived_secret_label) - 1, hash, mdlen,
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224 | preextractsec, mdlen, 1)) {
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225 | /* SSLfatal() already called */
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226 | EVP_PKEY_CTX_free(pctx);
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227 | return 0;
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228 | }
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229 |
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230 | prevsecret = preextractsec;
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231 | prevsecretlen = mdlen;
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232 | }
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233 |
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234 | ret = EVP_PKEY_derive_init(pctx) <= 0
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235 | || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY)
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236 | <= 0
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237 | || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
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238 | || EVP_PKEY_CTX_set1_hkdf_key(pctx, insecret, insecretlen) <= 0
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239 | || EVP_PKEY_CTX_set1_hkdf_salt(pctx, prevsecret, prevsecretlen)
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240 | <= 0
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241 | || EVP_PKEY_derive(pctx, outsecret, &mdlen)
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242 | <= 0;
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243 |
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244 | if (ret != 0)
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245 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
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246 | ERR_R_INTERNAL_ERROR);
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247 |
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248 | EVP_PKEY_CTX_free(pctx);
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249 | if (prevsecret == preextractsec)
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250 | OPENSSL_cleanse(preextractsec, mdlen);
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251 | return ret == 0;
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252 | }
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253 |
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254 | /*
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255 | * Given an input secret |insecret| of length |insecretlen| generate the
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256 | * handshake secret. This requires the early secret to already have been
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257 | * generated. Returns 1 on success 0 on failure.
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258 | */
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259 | int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
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260 | size_t insecretlen)
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261 | {
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262 | /* Calls SSLfatal() if required */
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263 | return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
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264 | insecret, insecretlen,
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265 | (unsigned char *)&s->handshake_secret);
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266 | }
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267 |
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268 | /*
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269 | * Given the handshake secret |prev| of length |prevlen| generate the master
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270 | * secret and store its length in |*secret_size|. Returns 1 on success 0 on
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271 | * failure.
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272 | */
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273 | int tls13_generate_master_secret(SSL *s, unsigned char *out,
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274 | unsigned char *prev, size_t prevlen,
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275 | size_t *secret_size)
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276 | {
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277 | const EVP_MD *md = ssl_handshake_md(s);
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278 |
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279 | *secret_size = EVP_MD_size(md);
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280 | /* Calls SSLfatal() if required */
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281 | return tls13_generate_secret(s, md, prev, NULL, 0, out);
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282 | }
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283 |
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284 | /*
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285 | * Generates the mac for the Finished message. Returns the length of the MAC or
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286 | * 0 on error.
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287 | */
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288 | size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
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289 | unsigned char *out)
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290 | {
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291 | const EVP_MD *md = ssl_handshake_md(s);
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292 | unsigned char hash[EVP_MAX_MD_SIZE];
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293 | size_t hashlen, ret = 0;
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294 | EVP_PKEY *key = NULL;
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295 | EVP_MD_CTX *ctx = EVP_MD_CTX_new();
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296 |
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297 | if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
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298 | /* SSLfatal() already called */
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299 | goto err;
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300 | }
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301 |
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302 | if (str == s->method->ssl3_enc->server_finished_label) {
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303 | key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
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304 | s->server_finished_secret, hashlen);
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305 | } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
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306 | key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL,
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307 | s->client_finished_secret, hashlen);
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308 | } else {
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309 | unsigned char finsecret[EVP_MAX_MD_SIZE];
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310 |
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311 | if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
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312 | s->client_app_traffic_secret,
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313 | finsecret, hashlen))
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314 | goto err;
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315 |
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316 | key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret,
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317 | hashlen);
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318 | OPENSSL_cleanse(finsecret, sizeof(finsecret));
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319 | }
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320 |
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321 | if (key == NULL
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322 | || ctx == NULL
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323 | || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0
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324 | || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0
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325 | || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) {
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326 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC,
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327 | ERR_R_INTERNAL_ERROR);
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328 | goto err;
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329 | }
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330 |
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331 | ret = hashlen;
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332 | err:
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333 | EVP_PKEY_free(key);
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334 | EVP_MD_CTX_free(ctx);
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335 | return ret;
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336 | }
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337 |
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338 | /*
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339 | * There isn't really a key block in TLSv1.3, but we still need this function
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340 | * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
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341 | */
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342 | int tls13_setup_key_block(SSL *s)
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343 | {
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344 | const EVP_CIPHER *c;
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345 | const EVP_MD *hash;
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346 |
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347 | s->session->cipher = s->s3->tmp.new_cipher;
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348 | if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) {
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349 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK,
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350 | SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
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351 | return 0;
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352 | }
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353 |
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354 | s->s3->tmp.new_sym_enc = c;
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355 | s->s3->tmp.new_hash = hash;
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356 |
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357 | return 1;
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358 | }
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359 |
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360 | static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
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361 | const EVP_CIPHER *ciph,
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362 | const unsigned char *insecret,
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363 | const unsigned char *hash,
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364 | const unsigned char *label,
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365 | size_t labellen, unsigned char *secret,
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366 | unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx)
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367 | {
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368 | unsigned char key[EVP_MAX_KEY_LENGTH];
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369 | size_t ivlen, keylen, taglen;
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370 | int hashleni = EVP_MD_size(md);
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371 | size_t hashlen;
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372 |
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373 | /* Ensure cast to size_t is safe */
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374 | if (!ossl_assert(hashleni >= 0)) {
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375 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
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376 | ERR_R_EVP_LIB);
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377 | goto err;
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378 | }
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379 | hashlen = (size_t)hashleni;
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380 |
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381 | if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
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382 | secret, hashlen, 1)) {
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383 | /* SSLfatal() already called */
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384 | goto err;
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385 | }
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386 |
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387 | /* TODO(size_t): convert me */
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388 | keylen = EVP_CIPHER_key_length(ciph);
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389 | if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) {
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390 | uint32_t algenc;
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391 |
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392 | ivlen = EVP_CCM_TLS_IV_LEN;
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393 | if (s->s3->tmp.new_cipher != NULL) {
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394 | algenc = s->s3->tmp.new_cipher->algorithm_enc;
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395 | } else if (s->session->cipher != NULL) {
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396 | /* We've not selected a cipher yet - we must be doing early data */
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397 | algenc = s->session->cipher->algorithm_enc;
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398 | } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
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399 | /* We must be doing early data with out-of-band PSK */
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400 | algenc = s->psksession->cipher->algorithm_enc;
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401 | } else {
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402 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
|
---|
403 | ERR_R_EVP_LIB);
|
---|
404 | goto err;
|
---|
405 | }
|
---|
406 | if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
|
---|
407 | taglen = EVP_CCM8_TLS_TAG_LEN;
|
---|
408 | else
|
---|
409 | taglen = EVP_CCM_TLS_TAG_LEN;
|
---|
410 | } else {
|
---|
411 | ivlen = EVP_CIPHER_iv_length(ciph);
|
---|
412 | taglen = 0;
|
---|
413 | }
|
---|
414 |
|
---|
415 | if (!tls13_derive_key(s, md, secret, key, keylen)
|
---|
416 | || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
|
---|
417 | /* SSLfatal() already called */
|
---|
418 | goto err;
|
---|
419 | }
|
---|
420 |
|
---|
421 | if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
|
---|
422 | || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
|
---|
423 | || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
|
---|
424 | taglen, NULL))
|
---|
425 | || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
|
---|
426 | SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
|
---|
427 | ERR_R_EVP_LIB);
|
---|
428 | goto err;
|
---|
429 | }
|
---|
430 |
|
---|
431 | return 1;
|
---|
432 | err:
|
---|
433 | OPENSSL_cleanse(key, sizeof(key));
|
---|
434 | return 0;
|
---|
435 | }
|
---|
436 |
|
---|
437 | int tls13_change_cipher_state(SSL *s, int which)
|
---|
438 | {
|
---|
439 | #ifdef CHARSET_EBCDIC
|
---|
440 | static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
|
---|
441 | static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
|
---|
442 | static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
|
---|
443 | static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
|
---|
444 | static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
|
---|
445 | static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
|
---|
446 | static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
|
---|
447 | static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
|
---|
448 | #else
|
---|
449 | static const unsigned char client_early_traffic[] = "c e traffic";
|
---|
450 | static const unsigned char client_handshake_traffic[] = "c hs traffic";
|
---|
451 | static const unsigned char client_application_traffic[] = "c ap traffic";
|
---|
452 | static const unsigned char server_handshake_traffic[] = "s hs traffic";
|
---|
453 | static const unsigned char server_application_traffic[] = "s ap traffic";
|
---|
454 | static const unsigned char exporter_master_secret[] = "exp master";
|
---|
455 | static const unsigned char resumption_master_secret[] = "res master";
|
---|
456 | static const unsigned char early_exporter_master_secret[] = "e exp master";
|
---|
457 | #endif
|
---|
458 | unsigned char *iv;
|
---|
459 | unsigned char secret[EVP_MAX_MD_SIZE];
|
---|
460 | unsigned char hashval[EVP_MAX_MD_SIZE];
|
---|
461 | unsigned char *hash = hashval;
|
---|
462 | unsigned char *insecret;
|
---|
463 | unsigned char *finsecret = NULL;
|
---|
464 | const char *log_label = NULL;
|
---|
465 | EVP_CIPHER_CTX *ciph_ctx;
|
---|
466 | size_t finsecretlen = 0;
|
---|
467 | const unsigned char *label;
|
---|
468 | size_t labellen, hashlen = 0;
|
---|
469 | int ret = 0;
|
---|
470 | const EVP_MD *md = NULL;
|
---|
471 | const EVP_CIPHER *cipher = NULL;
|
---|
472 |
|
---|
473 | if (which & SSL3_CC_READ) {
|
---|
474 | if (s->enc_read_ctx != NULL) {
|
---|
475 | EVP_CIPHER_CTX_reset(s->enc_read_ctx);
|
---|
476 | } else {
|
---|
477 | s->enc_read_ctx = EVP_CIPHER_CTX_new();
|
---|
478 | if (s->enc_read_ctx == NULL) {
|
---|
479 | SSLfatal(s, SSL_AD_INTERNAL_ERROR,
|
---|
480 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
|
---|
481 | goto err;
|
---|
482 | }
|
---|
483 | }
|
---|
484 | ciph_ctx = s->enc_read_ctx;
|
---|
485 | iv = s->read_iv;
|
---|
486 |
|
---|
487 | RECORD_LAYER_reset_read_sequence(&s->rlayer);
|
---|
488 | } else {
|
---|
489 | s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
|
---|
490 | if (s->enc_write_ctx != NULL) {
|
---|
491 | EVP_CIPHER_CTX_reset(s->enc_write_ctx);
|
---|
492 | } else {
|
---|
493 | s->enc_write_ctx = EVP_CIPHER_CTX_new();
|
---|
494 | if (s->enc_write_ctx == NULL) {
|
---|
495 | SSLfatal(s, SSL_AD_INTERNAL_ERROR,
|
---|
496 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
|
---|
497 | goto err;
|
---|
498 | }
|
---|
499 | }
|
---|
500 | ciph_ctx = s->enc_write_ctx;
|
---|
501 | iv = s->write_iv;
|
---|
502 |
|
---|
503 | RECORD_LAYER_reset_write_sequence(&s->rlayer);
|
---|
504 | }
|
---|
505 |
|
---|
506 | if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
|
---|
507 | || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
|
---|
508 | if (which & SSL3_CC_EARLY) {
|
---|
509 | EVP_MD_CTX *mdctx = NULL;
|
---|
510 | long handlen;
|
---|
511 | void *hdata;
|
---|
512 | unsigned int hashlenui;
|
---|
513 | const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
|
---|
514 |
|
---|
515 | insecret = s->early_secret;
|
---|
516 | label = client_early_traffic;
|
---|
517 | labellen = sizeof(client_early_traffic) - 1;
|
---|
518 | log_label = CLIENT_EARLY_LABEL;
|
---|
519 |
|
---|
520 | handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
|
---|
521 | if (handlen <= 0) {
|
---|
522 | SSLfatal(s, SSL_AD_INTERNAL_ERROR,
|
---|
523 | SSL_F_TLS13_CHANGE_CIPHER_STATE,
|
---|
524 | SSL_R_BAD_HANDSHAKE_LENGTH);
|
---|
525 | goto err;
|
---|
526 | }
|
---|
527 |
|
---|
528 | if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
|
---|
529 | && s->max_early_data > 0
|
---|
530 | && s->session->ext.max_early_data == 0) {
|
---|
531 | /*
|
---|
532 | * If we are attempting to send early data, and we've decided to
|
---|
533 | * actually do it but max_early_data in s->session is 0 then we
|
---|
534 | * must be using an external PSK.
|
---|
535 | */
|
---|
536 | if (!ossl_assert(s->psksession != NULL
|
---|
537 | && s->max_early_data ==
|
---|
538 | s->psksession->ext.max_early_data)) {
|
---|
539 | SSLfatal(s, SSL_AD_INTERNAL_ERROR,
|
---|
540 | SSL_F_TLS13_CHANGE_CIPHER_STATE,
|
---|
541 | ERR_R_INTERNAL_ERROR);
|
---|
542 | goto err;
|
---|
543 | }
|
---|
544 | sslcipher = SSL_SESSION_get0_cipher(s->psksession);
|
---|
545 | }
|
---|
546 | if (sslcipher == NULL) {
|
---|
547 | SSLfatal(s, SSL_AD_INTERNAL_ERROR,
|
---|
548 | SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK);
|
---|
549 | goto err;
|
---|
550 | }
|
---|
551 |
|
---|
552 | /*
|
---|
553 | * We need to calculate the handshake digest using the digest from
|
---|
554 | * the session. We haven't yet selected our ciphersuite so we can't
|
---|
555 | * use ssl_handshake_md().
|
---|
556 | */
|
---|
557 | mdctx = EVP_MD_CTX_new();
|
---|
558 | if (mdctx == NULL) {
|
---|
559 | SSLfatal(s, SSL_AD_INTERNAL_ERROR,
|
---|
560 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
|
---|
561 | goto err;
|
---|
562 | }
|
---|
563 | cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher));
|
---|
564 | md = ssl_md(sslcipher->algorithm2);
|
---|
565 | if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
|
---|
566 | || !EVP_DigestUpdate(mdctx, hdata, handlen)
|
---|
567 | || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
|
---|
568 | SSLfatal(s, SSL_AD_INTERNAL_ERROR,
|
---|
569 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
|
---|
570 | EVP_MD_CTX_free(mdctx);
|
---|
571 | goto err;
|
---|
572 | }
|
---|
573 | hashlen = hashlenui;
|
---|
574 | EVP_MD_CTX_free(mdctx);
|
---|
575 |
|
---|
576 | if (!tls13_hkdf_expand(s, md, insecret,
|
---|
577 | early_exporter_master_secret,
|
---|
578 | sizeof(early_exporter_master_secret) - 1,
|
---|
579 | hashval, hashlen,
|
---|
580 | s->early_exporter_master_secret, hashlen,
|
---|
581 | 1)) {
|
---|
582 | SSLfatal(s, SSL_AD_INTERNAL_ERROR,
|
---|
583 | SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
|
---|
584 | goto err;
|
---|
585 | }
|
---|
586 |
|
---|
587 | if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
|
---|
588 | s->early_exporter_master_secret, hashlen)) {
|
---|
589 | /* SSLfatal() already called */
|
---|
590 | goto err;
|
---|
591 | }
|
---|
592 | } else if (which & SSL3_CC_HANDSHAKE) {
|
---|
593 | insecret = s->handshake_secret;
|
---|
594 | finsecret = s->client_finished_secret;
|
---|
595 | finsecretlen = EVP_MD_size(ssl_handshake_md(s));
|
---|
596 | label = client_handshake_traffic;
|
---|
597 | labellen = sizeof(client_handshake_traffic) - 1;
|
---|
598 | log_label = CLIENT_HANDSHAKE_LABEL;
|
---|
599 | /*
|
---|
600 | * The handshake hash used for the server read/client write handshake
|
---|
601 | * traffic secret is the same as the hash for the server
|
---|
602 | * write/client read handshake traffic secret. However, if we
|
---|
603 | * processed early data then we delay changing the server
|
---|
604 | * read/client write cipher state until later, and the handshake
|
---|
605 | * hashes have moved on. Therefore we use the value saved earlier
|
---|
606 | * when we did the server write/client read change cipher state.
|
---|
607 | */
|
---|
608 | hash = s->handshake_traffic_hash;
|
---|
609 | } else {
|
---|
610 | insecret = s->master_secret;
|
---|
611 | label = client_application_traffic;
|
---|
612 | labellen = sizeof(client_application_traffic) - 1;
|
---|
613 | log_label = CLIENT_APPLICATION_LABEL;
|
---|
614 | /*
|
---|
615 | * For this we only use the handshake hashes up until the server
|
---|
616 | * Finished hash. We do not include the client's Finished, which is
|
---|
617 | * what ssl_handshake_hash() would give us. Instead we use the
|
---|
618 | * previously saved value.
|
---|
619 | */
|
---|
620 | hash = s->server_finished_hash;
|
---|
621 | }
|
---|
622 | } else {
|
---|
623 | /* Early data never applies to client-read/server-write */
|
---|
624 | if (which & SSL3_CC_HANDSHAKE) {
|
---|
625 | insecret = s->handshake_secret;
|
---|
626 | finsecret = s->server_finished_secret;
|
---|
627 | finsecretlen = EVP_MD_size(ssl_handshake_md(s));
|
---|
628 | label = server_handshake_traffic;
|
---|
629 | labellen = sizeof(server_handshake_traffic) - 1;
|
---|
630 | log_label = SERVER_HANDSHAKE_LABEL;
|
---|
631 | } else {
|
---|
632 | insecret = s->master_secret;
|
---|
633 | label = server_application_traffic;
|
---|
634 | labellen = sizeof(server_application_traffic) - 1;
|
---|
635 | log_label = SERVER_APPLICATION_LABEL;
|
---|
636 | }
|
---|
637 | }
|
---|
638 |
|
---|
639 | if (!(which & SSL3_CC_EARLY)) {
|
---|
640 | md = ssl_handshake_md(s);
|
---|
641 | cipher = s->s3->tmp.new_sym_enc;
|
---|
642 | if (!ssl3_digest_cached_records(s, 1)
|
---|
643 | || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
|
---|
644 | /* SSLfatal() already called */;
|
---|
645 | goto err;
|
---|
646 | }
|
---|
647 | }
|
---|
648 |
|
---|
649 | /*
|
---|
650 | * Save the hash of handshakes up to now for use when we calculate the
|
---|
651 | * client application traffic secret
|
---|
652 | */
|
---|
653 | if (label == server_application_traffic)
|
---|
654 | memcpy(s->server_finished_hash, hashval, hashlen);
|
---|
655 |
|
---|
656 | if (label == server_handshake_traffic)
|
---|
657 | memcpy(s->handshake_traffic_hash, hashval, hashlen);
|
---|
658 |
|
---|
659 | if (label == client_application_traffic) {
|
---|
660 | /*
|
---|
661 | * We also create the resumption master secret, but this time use the
|
---|
662 | * hash for the whole handshake including the Client Finished
|
---|
663 | */
|
---|
664 | if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
|
---|
665 | resumption_master_secret,
|
---|
666 | sizeof(resumption_master_secret) - 1,
|
---|
667 | hashval, hashlen, s->resumption_master_secret,
|
---|
668 | hashlen, 1)) {
|
---|
669 | /* SSLfatal() already called */
|
---|
670 | goto err;
|
---|
671 | }
|
---|
672 | }
|
---|
673 |
|
---|
674 | if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
|
---|
675 | insecret, hash, label, labellen, secret, iv,
|
---|
676 | ciph_ctx)) {
|
---|
677 | /* SSLfatal() already called */
|
---|
678 | goto err;
|
---|
679 | }
|
---|
680 |
|
---|
681 | if (label == server_application_traffic) {
|
---|
682 | memcpy(s->server_app_traffic_secret, secret, hashlen);
|
---|
683 | /* Now we create the exporter master secret */
|
---|
684 | if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
|
---|
685 | exporter_master_secret,
|
---|
686 | sizeof(exporter_master_secret) - 1,
|
---|
687 | hash, hashlen, s->exporter_master_secret,
|
---|
688 | hashlen, 1)) {
|
---|
689 | /* SSLfatal() already called */
|
---|
690 | goto err;
|
---|
691 | }
|
---|
692 |
|
---|
693 | if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
|
---|
694 | hashlen)) {
|
---|
695 | /* SSLfatal() already called */
|
---|
696 | goto err;
|
---|
697 | }
|
---|
698 | } else if (label == client_application_traffic)
|
---|
699 | memcpy(s->client_app_traffic_secret, secret, hashlen);
|
---|
700 |
|
---|
701 | if (!ssl_log_secret(s, log_label, secret, hashlen)) {
|
---|
702 | /* SSLfatal() already called */
|
---|
703 | goto err;
|
---|
704 | }
|
---|
705 |
|
---|
706 | if (finsecret != NULL
|
---|
707 | && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
|
---|
708 | finsecret, finsecretlen)) {
|
---|
709 | /* SSLfatal() already called */
|
---|
710 | goto err;
|
---|
711 | }
|
---|
712 |
|
---|
713 | if (!s->server && label == client_early_traffic)
|
---|
714 | s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
|
---|
715 | else
|
---|
716 | s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
|
---|
717 | ret = 1;
|
---|
718 | err:
|
---|
719 | OPENSSL_cleanse(secret, sizeof(secret));
|
---|
720 | return ret;
|
---|
721 | }
|
---|
722 |
|
---|
723 | int tls13_update_key(SSL *s, int sending)
|
---|
724 | {
|
---|
725 | #ifdef CHARSET_EBCDIC
|
---|
726 | static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
|
---|
727 | #else
|
---|
728 | static const unsigned char application_traffic[] = "traffic upd";
|
---|
729 | #endif
|
---|
730 | const EVP_MD *md = ssl_handshake_md(s);
|
---|
731 | size_t hashlen = EVP_MD_size(md);
|
---|
732 | unsigned char *insecret, *iv;
|
---|
733 | unsigned char secret[EVP_MAX_MD_SIZE];
|
---|
734 | EVP_CIPHER_CTX *ciph_ctx;
|
---|
735 | int ret = 0;
|
---|
736 |
|
---|
737 | if (s->server == sending)
|
---|
738 | insecret = s->server_app_traffic_secret;
|
---|
739 | else
|
---|
740 | insecret = s->client_app_traffic_secret;
|
---|
741 |
|
---|
742 | if (sending) {
|
---|
743 | s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
|
---|
744 | iv = s->write_iv;
|
---|
745 | ciph_ctx = s->enc_write_ctx;
|
---|
746 | RECORD_LAYER_reset_write_sequence(&s->rlayer);
|
---|
747 | } else {
|
---|
748 | iv = s->read_iv;
|
---|
749 | ciph_ctx = s->enc_read_ctx;
|
---|
750 | RECORD_LAYER_reset_read_sequence(&s->rlayer);
|
---|
751 | }
|
---|
752 |
|
---|
753 | if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
|
---|
754 | s->s3->tmp.new_sym_enc, insecret, NULL,
|
---|
755 | application_traffic,
|
---|
756 | sizeof(application_traffic) - 1, secret, iv,
|
---|
757 | ciph_ctx)) {
|
---|
758 | /* SSLfatal() already called */
|
---|
759 | goto err;
|
---|
760 | }
|
---|
761 |
|
---|
762 | memcpy(insecret, secret, hashlen);
|
---|
763 |
|
---|
764 | s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
|
---|
765 | ret = 1;
|
---|
766 | err:
|
---|
767 | OPENSSL_cleanse(secret, sizeof(secret));
|
---|
768 | return ret;
|
---|
769 | }
|
---|
770 |
|
---|
771 | int tls13_alert_code(int code)
|
---|
772 | {
|
---|
773 | /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
|
---|
774 | if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
|
---|
775 | return code;
|
---|
776 |
|
---|
777 | return tls1_alert_code(code);
|
---|
778 | }
|
---|
779 |
|
---|
780 | int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
|
---|
781 | const char *label, size_t llen,
|
---|
782 | const unsigned char *context,
|
---|
783 | size_t contextlen, int use_context)
|
---|
784 | {
|
---|
785 | unsigned char exportsecret[EVP_MAX_MD_SIZE];
|
---|
786 | #ifdef CHARSET_EBCDIC
|
---|
787 | static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
|
---|
788 | #else
|
---|
789 | static const unsigned char exporterlabel[] = "exporter";
|
---|
790 | #endif
|
---|
791 | unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
|
---|
792 | const EVP_MD *md = ssl_handshake_md(s);
|
---|
793 | EVP_MD_CTX *ctx = EVP_MD_CTX_new();
|
---|
794 | unsigned int hashsize, datalen;
|
---|
795 | int ret = 0;
|
---|
796 |
|
---|
797 | if (ctx == NULL || !ossl_statem_export_allowed(s))
|
---|
798 | goto err;
|
---|
799 |
|
---|
800 | if (!use_context)
|
---|
801 | contextlen = 0;
|
---|
802 |
|
---|
803 | if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
|
---|
804 | || EVP_DigestUpdate(ctx, context, contextlen) <= 0
|
---|
805 | || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
|
---|
806 | || EVP_DigestInit_ex(ctx, md, NULL) <= 0
|
---|
807 | || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
|
---|
808 | || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
|
---|
809 | (const unsigned char *)label, llen,
|
---|
810 | data, datalen, exportsecret, hashsize, 0)
|
---|
811 | || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
|
---|
812 | sizeof(exporterlabel) - 1, hash, hashsize,
|
---|
813 | out, olen, 0))
|
---|
814 | goto err;
|
---|
815 |
|
---|
816 | ret = 1;
|
---|
817 | err:
|
---|
818 | EVP_MD_CTX_free(ctx);
|
---|
819 | return ret;
|
---|
820 | }
|
---|
821 |
|
---|
822 | int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
|
---|
823 | const char *label, size_t llen,
|
---|
824 | const unsigned char *context,
|
---|
825 | size_t contextlen)
|
---|
826 | {
|
---|
827 | #ifdef CHARSET_EBCDIC
|
---|
828 | static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
|
---|
829 | #else
|
---|
830 | static const unsigned char exporterlabel[] = "exporter";
|
---|
831 | #endif
|
---|
832 | unsigned char exportsecret[EVP_MAX_MD_SIZE];
|
---|
833 | unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
|
---|
834 | const EVP_MD *md;
|
---|
835 | EVP_MD_CTX *ctx = EVP_MD_CTX_new();
|
---|
836 | unsigned int hashsize, datalen;
|
---|
837 | int ret = 0;
|
---|
838 | const SSL_CIPHER *sslcipher;
|
---|
839 |
|
---|
840 | if (ctx == NULL || !ossl_statem_export_early_allowed(s))
|
---|
841 | goto err;
|
---|
842 |
|
---|
843 | if (!s->server && s->max_early_data > 0
|
---|
844 | && s->session->ext.max_early_data == 0)
|
---|
845 | sslcipher = SSL_SESSION_get0_cipher(s->psksession);
|
---|
846 | else
|
---|
847 | sslcipher = SSL_SESSION_get0_cipher(s->session);
|
---|
848 |
|
---|
849 | md = ssl_md(sslcipher->algorithm2);
|
---|
850 |
|
---|
851 | /*
|
---|
852 | * Calculate the hash value and store it in |data|. The reason why
|
---|
853 | * the empty string is used is that the definition of TLS-Exporter
|
---|
854 | * is like so:
|
---|
855 | *
|
---|
856 | * TLS-Exporter(label, context_value, key_length) =
|
---|
857 | * HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
|
---|
858 | * "exporter", Hash(context_value), key_length)
|
---|
859 | *
|
---|
860 | * Derive-Secret(Secret, Label, Messages) =
|
---|
861 | * HKDF-Expand-Label(Secret, Label,
|
---|
862 | * Transcript-Hash(Messages), Hash.length)
|
---|
863 | *
|
---|
864 | * Here Transcript-Hash is the cipher suite hash algorithm.
|
---|
865 | */
|
---|
866 | if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
|
---|
867 | || EVP_DigestUpdate(ctx, context, contextlen) <= 0
|
---|
868 | || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
|
---|
869 | || EVP_DigestInit_ex(ctx, md, NULL) <= 0
|
---|
870 | || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
|
---|
871 | || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
|
---|
872 | (const unsigned char *)label, llen,
|
---|
873 | data, datalen, exportsecret, hashsize, 0)
|
---|
874 | || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
|
---|
875 | sizeof(exporterlabel) - 1, hash, hashsize,
|
---|
876 | out, olen, 0))
|
---|
877 | goto err;
|
---|
878 |
|
---|
879 | ret = 1;
|
---|
880 | err:
|
---|
881 | EVP_MD_CTX_free(ctx);
|
---|
882 | return ret;
|
---|
883 | }
|
---|