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Diffstat (limited to 'lib/radius/crypto.c')
| -rw-r--r-- | lib/radius/crypto.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/lib/radius/crypto.c b/lib/radius/crypto.c new file mode 100644 index 0000000..02a223d --- /dev/null +++ b/lib/radius/crypto.c @@ -0,0 +1,233 @@ +/* +Copyright (c) 2011, Network RADIUS SARL +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + * Neither the name of the <organization> nor the + names of its contributors may be used to endorse or promote products + derived from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND +ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY +DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** \file crypto.c + * \brief Data obfuscation and signing, using MD5. + * + * The "encryption" methods defined here are export-safe. The + * technical cryptography name for these functions is "obfuscation". + * They cannot properly be called "encryption", in the same way that + * DES or AES performs encryption. + */ + +/** \cond PRIVATE */ + +#include <networkradius-devel/client.h> + + +ssize_t nr_password_encrypt(uint8_t *output, size_t outlen, + const uint8_t *input, size_t inlen, + const char *secret, const uint8_t *vector) +{ + size_t i, j, len; + uint8_t digest[16]; + NR_MD5_CTX ctx, secret_ctx; + + if (!output || (outlen < 16) || !input || (inlen == 0) || + !secret || !vector) { + return -NR_ERR_INVALID_ARG; + } + + len = inlen; + if (len > 128) return -NR_ERR_ATTR_OVERFLOW; + + len = (len + 0x0f) & ~0x0f; /* round up to 16 byte boundary */ + + if (outlen < len) return -NR_ERR_ATTR_OVERFLOW; + + memcpy(output, input, len); + memset(output + len, 0, 128 - len); + + nr_MD5Init(&secret_ctx); + nr_MD5Update(&secret_ctx, (const uint8_t *) secret, strlen(secret)); + + for (j = 0; j < len; j += 16) { + ctx = secret_ctx; + + if (j == 0) { + nr_MD5Update(&ctx, vector, 16); + nr_MD5Final(digest, &ctx); + } else { + nr_MD5Update(&ctx, &output[j - 16], 16); + nr_MD5Final(digest, &ctx); + } + + for (i = 0; i < 16; i++) { + output[i + j] ^= digest[i]; + } + } + + return len; +} + +#ifdef FLAG_ENCRYPT_TUNNEL_PASSWORD +ssize_t nr_tunnelpw_encrypt(uint8_t *output, size_t outlen, + const uint8_t *input, size_t inlen, + const char *secret, const uint8_t *vector) +{ + size_t i, j, len; + NR_MD5_CTX ctx, secret_ctx; + uint8_t digest[16]; + + if (!output || (outlen < 18) || !input || (inlen == 0) || + !secret || !vector) { + return -NR_ERR_INVALID_ARG; + } + + len = ((inlen + 1) + 0x0f) & ~0x0f; + if (len > 251) return -NR_ERR_ATTR_OVERFLOW; + + output[0] = (nr_rand() & 0xff) | 0x80; + output[1] = nr_rand() & 0xff; + output[2] = inlen; + + memcpy(output + 3, input, inlen); + memset(output + 3 + inlen, 0, len - inlen - 1); + + nr_MD5Init(&secret_ctx); + nr_MD5Update(&secret_ctx, (const uint8_t *) secret, strlen(secret)); + + for (j = 0; j < len; j += 16) { + ctx = secret_ctx; + + if (j == 0) { + nr_MD5Update(&ctx, vector, 16); + nr_MD5Update(&ctx, output, 2); + nr_MD5Final(digest, &ctx); + } else { + nr_MD5Update(&ctx, &output[j + 2 - 16], 16); + nr_MD5Final(digest, &ctx); + } + + for (i = 0; i < 16; i++) { + output[i + j + 2] ^= digest[i]; + } + } + + return len + 2; +} + +ssize_t nr_tunnelpw_decrypt(uint8_t *output, size_t outlen, + const uint8_t *input, size_t inlen, + const char *secret, const uint8_t *vector) +{ + size_t i, j, len, encoded_len; + NR_MD5_CTX ctx, secret_ctx; + uint8_t digest[16]; + + if (!output || (outlen < 1) || !input || (inlen < 2) || + !secret || !vector) { + return -NR_ERR_INVALID_ARG; + } + + if (inlen <= 3) { + output[0] = 0; + return 0; + } + + len = inlen - 2; + + if (outlen < (len - 1)) return -NR_ERR_ATTR_OVERFLOW; + + nr_MD5Init(&secret_ctx); + nr_MD5Update(&secret_ctx, (const uint8_t *) secret, strlen(secret)); + + ctx = secret_ctx; + + nr_MD5Update(&ctx, vector, 16); /* MD5(secret + vector + salt) */ + nr_MD5Update(&ctx, input, 2); + nr_MD5Final(digest, &ctx); + + encoded_len = input[2] ^ digest[0]; + if (encoded_len >= len) { + return -NR_ERR_ATTR_TOO_LARGE; + } + + for (i = 0; i < 15; i++) { + output[i] = input[i + 3] ^ digest[i + 1]; + } + + for (j = 16; j < len; j += 16) { + ctx = secret_ctx; + + nr_MD5Update(&ctx, input + j - 16 + 2, 16); + nr_MD5Final(digest, &ctx); + + for (i = 0; i < 16; i++) { + output[i + j - 1] = input[i + j + 2] ^ digest[i]; + } + + + } + + output[encoded_len] = '\0'; + return encoded_len; +} +#endif + +void +nr_hmac_md5(const uint8_t *data, size_t data_len, + const uint8_t *key, size_t key_len, + uint8_t digest[16]) +{ + size_t i; + uint8_t k_ipad[64]; + uint8_t k_opad[64]; + uint8_t tk[16]; + NR_MD5_CTX ctx; + + if (key_len > 64) { + nr_MD5Init(&ctx); + nr_MD5Update(&ctx, key, key_len); + nr_MD5Final(tk, &ctx); + + key = tk; + key_len = 16; + } + + memset(k_ipad, 0, sizeof(k_ipad)); + memset(k_opad, 0, sizeof(k_opad)); + memcpy(k_ipad, key, key_len); + memcpy(k_opad, key, key_len); + + for (i = 0; i < sizeof(k_ipad); i++) { + k_ipad[i] ^= 0x36; + k_opad[i] ^= 0x5c; + } + + nr_MD5Init(&ctx); + nr_MD5Update(&ctx, k_ipad, sizeof(k_ipad)); + nr_MD5Update(&ctx, data, data_len); + nr_MD5Final(digest, &ctx); + + nr_MD5Init(&ctx); + nr_MD5Update(&ctx, k_opad, sizeof(k_opad)); + nr_MD5Update(&ctx, digest, 16); + nr_MD5Final(digest, &ctx); +} + +/** \endcond */ |