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00015 #include "includes.h"
00016
00017 #include "common.h"
00018 #include "rsa.h"
00019 #include "pkcs1.h"
00020
00021
00022 static int pkcs1_generate_encryption_block(u8 block_type, size_t modlen,
00023 const u8 *in, size_t inlen,
00024 u8 *out, size_t *outlen)
00025 {
00026 size_t ps_len;
00027 u8 *pos;
00028
00029
00030
00031
00032
00033
00034
00035
00036
00037
00038
00039 if (modlen < 12 || modlen > *outlen || inlen > modlen - 11) {
00040 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Invalid buffer "
00041 "lengths (modlen=%lu outlen=%lu inlen=%lu)",
00042 __func__, (unsigned long) modlen,
00043 (unsigned long) *outlen,
00044 (unsigned long) inlen);
00045 return -1;
00046 }
00047
00048 pos = out;
00049 *pos++ = 0x00;
00050 *pos++ = block_type;
00051 ps_len = modlen - inlen - 3;
00052 switch (block_type) {
00053 case 0:
00054 os_memset(pos, 0x00, ps_len);
00055 pos += ps_len;
00056 break;
00057 case 1:
00058 os_memset(pos, 0xff, ps_len);
00059 pos += ps_len;
00060 break;
00061 case 2:
00062 if (os_get_random(pos, ps_len) < 0) {
00063 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Failed to get "
00064 "random data for PS", __func__);
00065 return -1;
00066 }
00067 while (ps_len--) {
00068 if (*pos == 0x00)
00069 *pos = 0x01;
00070 pos++;
00071 }
00072 break;
00073 default:
00074 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Unsupported block type "
00075 "%d", __func__, block_type);
00076 return -1;
00077 }
00078 *pos++ = 0x00;
00079 os_memcpy(pos, in, inlen);
00080
00081 return 0;
00082 }
00083
00084
00085 int pkcs1_encrypt(int block_type, struct crypto_rsa_key *key,
00086 int use_private, const u8 *in, size_t inlen,
00087 u8 *out, size_t *outlen)
00088 {
00089 size_t modlen;
00090
00091 modlen = crypto_rsa_get_modulus_len(key);
00092
00093 if (pkcs1_generate_encryption_block(block_type, modlen, in, inlen,
00094 out, outlen) < 0)
00095 return -1;
00096
00097 return crypto_rsa_exptmod(out, modlen, out, outlen, key, use_private);
00098 }
00099
00100
00101 int pkcs1_v15_private_key_decrypt(struct crypto_rsa_key *key,
00102 const u8 *in, size_t inlen,
00103 u8 *out, size_t *outlen)
00104 {
00105 int res;
00106 u8 *pos, *end;
00107
00108 res = crypto_rsa_exptmod(in, inlen, out, outlen, key, 1);
00109 if (res)
00110 return res;
00111
00112 if (*outlen < 2 || out[0] != 0 || out[1] != 2)
00113 return -1;
00114
00115
00116 pos = out + 2;
00117 end = out + *outlen;
00118 while (*pos && pos < end)
00119 pos++;
00120 if (pos == end)
00121 return -1;
00122 pos++;
00123
00124 *outlen -= pos - out;
00125
00126
00127 os_memmove(out, pos, *outlen);
00128
00129 return 0;
00130 }
00131
00132
00133 int pkcs1_decrypt_public_key(struct crypto_rsa_key *key,
00134 const u8 *crypt, size_t crypt_len,
00135 u8 *plain, size_t *plain_len)
00136 {
00137 size_t len;
00138 u8 *pos;
00139
00140 len = *plain_len;
00141 if (crypto_rsa_exptmod(crypt, crypt_len, plain, &len, key, 0) < 0)
00142 return -1;
00143
00144
00145
00146
00147
00148
00149
00150
00151
00152
00153 if (len < 3 + 8 + 16 ||
00154 plain[0] != 0x00 || (plain[1] != 0x00 && plain[1] != 0x01)) {
00155 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
00156 "structure");
00157 return -1;
00158 }
00159
00160 pos = plain + 3;
00161 if (plain[1] == 0x00) {
00162
00163 if (plain[2] != 0x00) {
00164 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature "
00165 "PS (BT=00)");
00166 return -1;
00167 }
00168 while (pos + 1 < plain + len && *pos == 0x00 && pos[1] == 0x00)
00169 pos++;
00170 } else {
00171
00172 if (plain[2] != 0xff) {
00173 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature "
00174 "PS (BT=01)");
00175 return -1;
00176 }
00177 while (pos < plain + len && *pos == 0xff)
00178 pos++;
00179 }
00180
00181 if (pos - plain - 2 < 8) {
00182
00183 wpa_printf(MSG_INFO, "LibTomCrypt: Too short signature "
00184 "padding");
00185 return -1;
00186 }
00187
00188 if (pos + 16 >= plain + len || *pos != 0x00) {
00189 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
00190 "structure (2)");
00191 return -1;
00192 }
00193 pos++;
00194 len -= pos - plain;
00195
00196
00197 os_memmove(plain, pos, len);
00198 *plain_len = len;
00199
00200 return 0;
00201 }