Flawfinder version 2.0.10, (C) 2001-2019 David A. Wheeler.
Number of rules (primarily dangerous function names) in C/C++ ruleset: 223
Examining data/libcotp-1.2.3/src/cotp.h
Examining data/libcotp-1.2.3/src/otp.c
Examining data/libcotp-1.2.3/tests/test_otp.c

FINAL RESULTS:

data/libcotp-1.2.3/src/otp.c:144:9:  [4] (format) snprintf:
  If format strings can be influenced by an attacker, they can be exploited,
  and note that sprintf variations do not always \0-terminate (CWE-134). Use
  a constant for the format specification.
        snprintf (token, digits_length + 1, fmt, tk);
data/libcotp-1.2.3/src/otp.c:60:5:  [2] (buffer) char:
  Statically-sized arrays can be improperly restricted, leading to potential
  overflows or other issues (CWE-119!/CWE-120). Perform bounds checking, use
  functions that limit length, or ensure that the size is larger than the
  maximum possible length.
    char code[6];
data/libcotp-1.2.3/src/otp.c:113:14:  [2] (buffer) char:
  Statically-sized arrays can be improperly restricted, leading to potential
  overflows or other issues (CWE-119!/CWE-120). Perform bounds checking, use
  functions that limit length, or ensure that the size is larger than the
  maximum possible length.
    unsigned char C_reverse_byte_order[8];
data/libcotp-1.2.3/src/otp.c:141:9:  [2] (buffer) memcpy:
  Does not check for buffer overflows when copying to destination (CWE-120).
  Make sure destination can always hold the source data.
        memcpy (fmt, "%.", 2);
data/libcotp-1.2.3/src/otp.c:143:9:  [2] (buffer) memcpy:
  Does not check for buffer overflows when copying to destination (CWE-120).
  Make sure destination can always hold the source data.
        memcpy (fmt + 3 + extra_char, "d", 2);
data/libcotp-1.2.3/src/otp.c:33:27:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
    char *nK = calloc (1, strlen (K) + 1);
data/libcotp-1.2.3/src/otp.c:62:30:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
        int mod = bin_code % strlen(steam_alphabet);
data/libcotp-1.2.3/src/otp.c:63:31:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
        bin_code = bin_code / strlen(steam_alphabet);
data/libcotp-1.2.3/src/otp.c:104:36:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
    size_t secret_len = (size_t) ((strlen(K) + 1.6 - 1) / 1.6);
data/libcotp-1.2.3/src/otp.c:107:57:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
    unsigned char *secret = base32_decode(normalized_K, strlen(normalized_K), &err);
data/libcotp-1.2.3/tests/test_otp.c:13:39:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
    char *K_base32 = base32_encode(K, strlen(K)+1, &base_err);
data/libcotp-1.2.3/tests/test_otp.c:31:39:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
    char *K_base32 = base32_encode(K, strlen(K)+1, &base_err);
data/libcotp-1.2.3/tests/test_otp.c:48:39:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
    char *K_base32 = base32_encode(K, strlen(K)+1, &base_err);
data/libcotp-1.2.3/tests/test_otp.c:66:39:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
    char *K_base32 = base32_encode(K, strlen(K)+1, &base_err);
data/libcotp-1.2.3/tests/test_otp.c:84:39:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
    char *K_base32 = base32_encode(K, strlen(K)+1, &base_err);
data/libcotp-1.2.3/tests/test_otp.c:209:49:  [1] (buffer) strlen:
  Does not handle strings that are not \0-terminated; if given one it may
  perform an over-read (it could cause a crash if unprotected) (CWE-126).
    char *secret_base32 = base32_encode(secret, strlen(secret)+1, &base_err);

ANALYSIS SUMMARY:

Hits = 16
Lines analyzed = 604 in approximately 0.03 seconds (18008 lines/second)
Physical Source Lines of Code (SLOC) = 460
Hits@level = [0]   3 [1]  11 [2]   4 [3]   0 [4]   1 [5]   0
Hits@level+ = [0+]  19 [1+]  16 [2+]   5 [3+]   1 [4+]   1 [5+]   0
Hits/KSLOC@level+ = [0+] 41.3043 [1+] 34.7826 [2+] 10.8696 [3+] 2.17391 [4+] 2.17391 [5+]   0
Dot directories skipped = 1 (--followdotdir overrides)
Minimum risk level = 1
Not every hit is necessarily a security vulnerability.
There may be other security vulnerabilities; review your code!
See 'Secure Programming HOWTO'
(https://dwheeler.com/secure-programs) for more information.