diff options
Diffstat (limited to 'src/openvpn/ntlm.c')
-rw-r--r-- | src/openvpn/ntlm.c | 146 |
1 files changed, 90 insertions, 56 deletions
diff --git a/src/openvpn/ntlm.c b/src/openvpn/ntlm.c index 0b1163e..077fa3e 100644 --- a/src/openvpn/ntlm.c +++ b/src/openvpn/ntlm.c @@ -60,45 +60,47 @@ static void create_des_keys(const unsigned char *hash, unsigned char *key) { key[0] = hash[0]; - key[1] = ((hash[0]&1)<<7)|(hash[1]>>1); - key[2] = ((hash[1]&3)<<6)|(hash[2]>>2); - key[3] = ((hash[2]&7)<<5)|(hash[3]>>3); - key[4] = ((hash[3]&15)<<4)|(hash[4]>>4); - key[5] = ((hash[4]&31)<<3)|(hash[5]>>5); - key[6] = ((hash[5]&63)<<2)|(hash[6]>>6); - key[7] = ((hash[6]&127)<<1); + key[1] = ((hash[0] & 1) << 7) | (hash[1] >> 1); + key[2] = ((hash[1] & 3) << 6) | (hash[2] >> 2); + key[3] = ((hash[2] & 7) << 5) | (hash[3] >> 3); + key[4] = ((hash[3] & 15) << 4) | (hash[4] >> 4); + key[5] = ((hash[4] & 31) << 3) | (hash[5] >> 5); + key[6] = ((hash[5] & 63) << 2) | (hash[6] >> 6); + key[7] = ((hash[6] & 127) << 1); key_des_fixup(key, 8, 1); } static void -gen_md4_hash(const char *data, int data_len, char *result) +gen_md4_hash(const uint8_t *data, int data_len, uint8_t *result) { /* result is 16 byte md4 hash */ const md_kt_t *md4_kt = md_kt_get("MD4"); - char md[MD4_DIGEST_LENGTH]; + uint8_t md[MD4_DIGEST_LENGTH]; md_full(md4_kt, data, data_len, md); memcpy(result, md, MD4_DIGEST_LENGTH); } static void -gen_hmac_md5(const char *data, int data_len, const char *key, int key_len,char *result) +gen_hmac_md5(const uint8_t *data, int data_len, const uint8_t *key, int key_len, + uint8_t *result) { const md_kt_t *md5_kt = md_kt_get("MD5"); hmac_ctx_t *hmac_ctx = hmac_ctx_new(); hmac_ctx_init(hmac_ctx, key, key_len, md5_kt); - hmac_ctx_update(hmac_ctx, (const unsigned char *)data, data_len); - hmac_ctx_final(hmac_ctx, (unsigned char *)result); + hmac_ctx_update(hmac_ctx, data, data_len); + hmac_ctx_final(hmac_ctx, result); hmac_ctx_cleanup(hmac_ctx); hmac_ctx_free(hmac_ctx); } static void -gen_timestamp(unsigned char *timestamp) +gen_timestamp(uint8_t *timestamp) { /* Copies 8 bytes long timestamp into "timestamp" buffer. - * Timestamp is Little-endian, 64-bit signed value representing the number of tenths of a microsecond since January 1, 1601. + * Timestamp is Little-endian, 64-bit signed value representing the + * number of tenths of a microsecond since January 1, 1601. */ UINTEGER64 timestamp_ull; @@ -129,8 +131,8 @@ gen_nonce(unsigned char *nonce) } } -void -my_strupr(unsigned char *str) +static void +my_strupr(char *str) { /* converts string to uppercase in place */ @@ -150,16 +152,17 @@ unicodize(char *dst, const char *src) { dst[i++] = *src; dst[i++] = 0; - } - while (*src++); + } while (*src++); return i; } static void -add_security_buffer(int sb_offset, void *data, int length, unsigned char *msg_buf, int *msg_bufpos) +add_security_buffer(int sb_offset, void *data, int length, + unsigned char *msg_buf, int *msg_bufpos) { - /* Adds security buffer data to a message and sets security buffer's offset and length */ + /* Adds security buffer data to a message and sets security buffer's + * offset and length */ msg_buf[sb_offset] = (unsigned char)length; msg_buf[sb_offset + 2] = msg_buf[sb_offset]; msg_buf[sb_offset + 4] = (unsigned char)(*msg_bufpos & 0xff); @@ -186,7 +189,8 @@ ntlm_phase_1(const struct http_proxy_info *p, struct gc_arena *gc) } const char * -ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, struct gc_arena *gc) +ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, + struct gc_arena *gc) { /* NTLM handshake * @@ -195,19 +199,19 @@ ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, struct gc_are */ char pwbuf[sizeof(p->up.password) * 2]; /* for unicode password */ - unsigned char buf2[128]; /* decoded reply from proxy */ - unsigned char phase3[464]; + uint8_t buf2[128]; /* decoded reply from proxy */ + uint8_t phase3[464]; - char md4_hash[MD4_DIGEST_LENGTH+5]; - char challenge[8], ntlm_response[24]; + uint8_t md4_hash[MD4_DIGEST_LENGTH + 5]; + uint8_t challenge[8], ntlm_response[24]; int i, ret_val; - char ntlmv2_response[144]; + uint8_t ntlmv2_response[144]; char userdomain_u[256]; /* for uppercase unicode username and domain */ char userdomain[128]; /* the same as previous but ascii */ - char ntlmv2_hash[MD5_DIGEST_LENGTH]; - char ntlmv2_hmacmd5[16]; - char *ntlmv2_blob = ntlmv2_response + 16; /* inside ntlmv2_response, length: 128 */ + uint8_t ntlmv2_hash[MD5_DIGEST_LENGTH]; + uint8_t ntlmv2_hmacmd5[16]; + uint8_t *ntlmv2_blob = ntlmv2_response + 16; /* inside ntlmv2_response, length: 128 */ int ntlmv2_blob_size = 0; int phase3_bufpos = 0x40; /* offset to next security buffer data to be added */ size_t len; @@ -246,12 +250,13 @@ ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, struct gc_are /* fill 1st 16 bytes with md4 hash, disregard terminating null */ - gen_md4_hash(pwbuf, unicodize(pwbuf, p->up.password) - 2, md4_hash); + int unicode_len = unicodize(pwbuf, p->up.password) - 2; + gen_md4_hash((uint8_t *)pwbuf, unicode_len, md4_hash); /* pad to 21 bytes */ memset(md4_hash + MD4_DIGEST_LENGTH, 0, 5); - ret_val = openvpn_base64_decode( phase_2, (void *)buf2, -1); + ret_val = openvpn_base64_decode(phase_2, buf2, -1); if (ret_val < 0) { return NULL; @@ -271,7 +276,8 @@ ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, struct gc_are int tib_len; /* NTLMv2 hash */ - my_strupr((unsigned char *)strcpy(userdomain, username)); + strcpy(userdomain, username); + my_strupr(userdomain); if (strlen(username) + strlen(domain) < sizeof(userdomain)) { strcat(userdomain, domain); @@ -281,34 +287,54 @@ ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, struct gc_are msg(M_INFO, "Warning: Username or domain too long"); } unicodize(userdomain_u, userdomain); - gen_hmac_md5(userdomain_u, 2 * strlen(userdomain), md4_hash, MD5_DIGEST_LENGTH, ntlmv2_hash); + gen_hmac_md5((uint8_t *)userdomain_u, 2 * strlen(userdomain), md4_hash, + MD5_DIGEST_LENGTH, ntlmv2_hash); /* NTLMv2 Blob */ memset(ntlmv2_blob, 0, 128); /* Clear blob buffer */ ntlmv2_blob[0x00] = 1; /* Signature */ ntlmv2_blob[0x01] = 1; /* Signature */ ntlmv2_blob[0x04] = 0; /* Reserved */ - gen_timestamp((unsigned char *)&ntlmv2_blob[0x08]); /* 64-bit Timestamp */ - gen_nonce((unsigned char *)&ntlmv2_blob[0x10]); /* 64-bit Client Nonce */ + gen_timestamp(&ntlmv2_blob[0x08]); /* 64-bit Timestamp */ + gen_nonce(&ntlmv2_blob[0x10]); /* 64-bit Client Nonce */ ntlmv2_blob[0x18] = 0; /* Unknown, zero should work */ /* Add target information block to the blob */ - if (( *((long *)&buf2[0x14]) & 0x00800000) == 0x00800000) /* Check for Target Information block */ + + /* Check for Target Information block */ + /* The NTLM spec instructs to interpret these 4 consecutive bytes as a + * 32bit long integer. However, no endianness is specified. + * The code here and that found in other NTLM implementations point + * towards the assumption that the byte order on the wire has to + * match the order on the sending and receiving hosts. Probably NTLM has + * been thought to be always running on x86_64/i386 machine thus + * implying Little-Endian everywhere. + * + * This said, in case of future changes, we should keep in mind that the + * byte order on the wire for the NTLM header is LE. + */ + const size_t hoff = 0x14; + unsigned long flags = buf2[hoff] | (buf2[hoff + 1] << 8) | + (buf2[hoff + 2] << 16) | (buf2[hoff + 3] << 24); + if ((flags & 0x00800000) == 0x00800000) { tib_len = buf2[0x28]; /* Get Target Information block size */ if (tib_len > 96) { tib_len = 96; } + { - char *tib_ptr; - int tib_pos = buf2[0x2c]; + uint8_t *tib_ptr; + uint8_t tib_pos = buf2[0x2c]; if (tib_pos + tib_len > sizeof(buf2)) { return NULL; } - tib_ptr = buf2 + tib_pos; /* Get Target Information block pointer */ - memcpy(&ntlmv2_blob[0x1c], tib_ptr, tib_len); /* Copy Target Information block into the blob */ + /* Get Target Information block pointer */ + tib_ptr = buf2 + tib_pos; + /* Copy Target Information block into the blob */ + memcpy(&ntlmv2_blob[0x1c], tib_ptr, tib_len); } } else @@ -316,7 +342,8 @@ ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, struct gc_are tib_len = 0; } - ntlmv2_blob[0x1c + tib_len] = 0; /* Unknown, zero works */ + /* Unknown, zero works */ + ntlmv2_blob[0x1c + tib_len] = 0; /* Get blob length */ ntlmv2_blob_size = 0x20 + tib_len; @@ -325,24 +352,28 @@ ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, struct gc_are memcpy(&ntlmv2_response[8], challenge, 8); /* hmac-md5 */ - gen_hmac_md5(&ntlmv2_response[8], ntlmv2_blob_size + 8, ntlmv2_hash, MD5_DIGEST_LENGTH, ntlmv2_hmacmd5); - - /* Add hmac-md5 result to the blob */ - memcpy(ntlmv2_response, ntlmv2_hmacmd5, MD5_DIGEST_LENGTH); /* Note: This overwrites challenge previously written at ntlmv2_response[8..15] */ + gen_hmac_md5(&ntlmv2_response[8], ntlmv2_blob_size + 8, ntlmv2_hash, + MD5_DIGEST_LENGTH, ntlmv2_hmacmd5); + /* Add hmac-md5 result to the blob. + * Note: This overwrites challenge previously written at + * ntlmv2_response[8..15] */ + memcpy(ntlmv2_response, ntlmv2_hmacmd5, MD5_DIGEST_LENGTH); } - else /* Generate NTLM response */ + else /* Generate NTLM response */ { - unsigned char key1[DES_KEY_LENGTH], key2[DES_KEY_LENGTH], key3[DES_KEY_LENGTH]; + unsigned char key1[DES_KEY_LENGTH], key2[DES_KEY_LENGTH]; + unsigned char key3[DES_KEY_LENGTH]; - create_des_keys((unsigned char *)md4_hash, key1); + create_des_keys(md4_hash, key1); cipher_des_encrypt_ecb(key1, challenge, ntlm_response); - create_des_keys((unsigned char *)&(md4_hash[DES_KEY_LENGTH-1]), key2); + create_des_keys(&md4_hash[DES_KEY_LENGTH - 1], key2); cipher_des_encrypt_ecb(key2, challenge, &ntlm_response[DES_KEY_LENGTH]); - create_des_keys((unsigned char *)&(md4_hash[2*(DES_KEY_LENGTH-1)]), key3); - cipher_des_encrypt_ecb(key3, challenge, &ntlm_response[DES_KEY_LENGTH*2]); + create_des_keys(&md4_hash[2 * (DES_KEY_LENGTH - 1)], key3); + cipher_des_encrypt_ecb(key3, challenge, + &ntlm_response[DES_KEY_LENGTH * 2]); } @@ -353,7 +384,8 @@ ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, struct gc_are if (ntlmv2_enabled) /* NTLMv2 response */ { - add_security_buffer(0x14, ntlmv2_response, ntlmv2_blob_size + 16, phase3, &phase3_bufpos); + add_security_buffer(0x14, ntlmv2_response, ntlmv2_blob_size + 16, + phase3, &phase3_bufpos); } else /* NTLM response */ { @@ -361,12 +393,13 @@ ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, struct gc_are } /* username in ascii */ - add_security_buffer(0x24, username, strlen(username), phase3, &phase3_bufpos); + add_security_buffer(0x24, username, strlen(username), phase3, + &phase3_bufpos); - /* Set domain. If <domain> is empty, default domain will be used (i.e. proxy's domain) */ + /* Set domain. If <domain> is empty, default domain will be used + * (i.e. proxy's domain) */ add_security_buffer(0x1c, domain, strlen(domain), phase3, &phase3_bufpos); - /* other security buffers will be empty */ phase3[0x10] = phase3_bufpos; /* lm not used */ phase3[0x30] = phase3_bufpos; /* no workstation name supplied */ @@ -376,7 +409,8 @@ ntlm_phase_3(const struct http_proxy_info *p, const char *phase_2, struct gc_are phase3[0x3c] = 0x02; /* negotiate oem */ phase3[0x3d] = 0x02; /* negotiate ntlm */ - return ((const char *)make_base64_string2((unsigned char *)phase3, phase3_bufpos, gc)); + return ((const char *)make_base64_string2((unsigned char *)phase3, + phase3_bufpos, gc)); } #else /* if NTLM */ |