1 /*
2  * ModSecurity, http://www.modsecurity.org/
3  * Copyright (c) 2015 - 2021 Trustwave Holdings, Inc. (http://www.trustwave.com/)
4  *
5  * You may not use this file except in compliance with
6  * the License.  You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * If any of the files related to licensing are missing or if you have any
11  * other questions related to licensing please contact Trustwave Holdings, Inc.
12  * directly using the email address security@modsecurity.org.
13  *
14  */
15 
16 #include "src/operators/verify_cpf.h"
17 
18 #include <string>
19 #include <list>
20 
21 #include "src/operators/operator.h"
22 
23 namespace modsecurity {
24 namespace operators {
25 
convert_to_int(const char c)26 int VerifyCPF::convert_to_int(const char c) {
27     int n;
28     if ((c >= '0') && (c <= '9')) {
29         n = c - '0';
30     } else if ((c >= 'A') && (c <= 'F')) {
31         n = c - 'A' + 10;
32     } else if ((c >= 'a') && (c <= 'f')) {
33         n = c - 'a' + 10;
34     } else {
35         n = 0;
36     }
37     return n;
38 }
39 
40 
verify(const char * cpfnumber,int len)41 bool VerifyCPF::verify(const char *cpfnumber, int len) {
42     int factor, part_1, part_2, var_len = len;
43     unsigned int sum = 0, i = 0, cpf_len = 11, c;
44     int cpf[11];
45     char s_cpf[11];
46 
47     while ((*cpfnumber != '\0') && (var_len > 0)) {
48         // Always true.
49         //if (*cpfnumber != '-' || *cpfnumber != '.') {
50             if (i < cpf_len && isdigit(*cpfnumber)) {
51                 s_cpf[i] = *cpfnumber;
52                 cpf[i] = convert_to_int(*cpfnumber);
53                 i++;
54             }
55         //}
56         cpfnumber++;
57         var_len--;
58     }
59 
60 
61     if (i != cpf_len) {
62         return 0;
63     } else {
64         for (i = 0; i< cpf_len; i++) {
65             if (strncmp(s_cpf, bad_cpf[i], cpf_len) == 0) {
66                 return 0;
67             }
68         }
69     }
70 
71     part_1 = convert_to_int(s_cpf[cpf_len-2]);
72     part_2 = convert_to_int(s_cpf[cpf_len-1]);
73 
74     c = cpf_len;
75 
76     for (i = 0; i < 9; i++) {
77         sum += (cpf[i] * --c);
78     }
79 
80     factor = (sum % cpf_len);
81 
82     if (factor < 2) {
83         cpf[9] = 0;
84     } else {
85         cpf[9] = cpf_len-factor;
86     }
87 
88     sum = 0;
89     c = cpf_len;
90 
91     for (i = 0; i < 10; i++) {
92         sum += (cpf[i] * c--);
93     }
94 
95     factor = (sum % cpf_len);
96 
97     if (factor < 2) {
98         cpf[10] = 0;
99     } else {
100         cpf[10] = cpf_len-factor;
101     }
102 
103     if (part_1 == cpf[9] && part_2 == cpf[10]) {
104         return true;
105     }
106 
107     return false;
108 }
109 
110 
evaluate(Transaction * t,RuleWithActions * rule,const std::string & input,std::shared_ptr<RuleMessage> ruleMessage)111 bool VerifyCPF::evaluate(Transaction *t, RuleWithActions *rule,
112     const std::string& input, std::shared_ptr<RuleMessage> ruleMessage) {
113     std::list<SMatch> matches;
114     bool is_cpf = false;
115     int i;
116 
117     if (m_param.empty()) {
118         return false;
119     }
120 
121     for (i = 0; i < input.size() - 1 && is_cpf == false; i++) {
122         matches = m_re->searchAll(input.substr(i, input.size()));
123         for (const auto & m : matches) {
124             is_cpf = verify(m.str().c_str(), m.str().size());
125             if (is_cpf) {
126                 logOffset(ruleMessage, m.offset(), m.str().size());
127                 if (rule && t && rule->hasCaptureAction()) {
128                     t->m_collections.m_tx_collection->storeOrUpdateFirst(
129                         "0", m.str());
130                     ms_dbg_a(t, 7, "Added VerifyCPF match TX.0: " + \
131                         m.str());
132                 }
133 
134                 goto out;
135             }
136         }
137     }
138 
139 out:
140     return is_cpf;
141 }
142 
143 
144 }  // namespace operators
145 }  // namespace modsecurity
146