diff options
Diffstat (limited to 'librecrypt_add_algorithm.c')
| -rw-r--r-- | librecrypt_add_algorithm.c | 129 |
1 files changed, 40 insertions, 89 deletions
diff --git a/librecrypt_add_algorithm.c b/librecrypt_add_algorithm.c index 4556c9b..b9fa71a 100644 --- a/librecrypt_add_algorithm.c +++ b/librecrypt_add_algorithm.c @@ -4,45 +4,26 @@ static size_t -truncated_asterisk(char *out_buffer, size_t out_buffer_size, size_t asterisk) -{ - struct concat_state concat_state = {out_buffer, out_buffer_size, 0u}; - librecrypt_concat_str_(&concat_state, "*"); - librecrypt_concat_uint_(&concat_state, asterisk); - if (concat_state.len < 2u) - abort(); /* $covered$ (impossible) */ - return concat_state.len; -} - - -static size_t measure_asterisk(size_t asterisk) { - return truncated_asterisk(NULL, 0u, asterisk); + struct concat_state concat_state = {NULL, 0u, 0u}; + librecrypt_concat_uint_(&concat_state, asterisk); + return (sizeof("*") - 1u) + concat_state.len; } ssize_t -librecrypt_add_algorithm(char *out_buffer, size_t size, const char *augend, +librecrypt_add_algorithm(char *out_buffer0, size_t size0, const char *augend, const char *restrict augment, LIBRECRYPT_CONTEXT *ctx) { - /* TODO rewrite to use the string building functions */ - - size_t prefix1, prefix2, min, ret, len, phraselen; + struct concat_state concat_state = {out_buffer0, size0, 0u}; + size_t prefix1, prefix2, len, conf_len, phraselen; size_t hashsize1, hashsize2, asterisk_len; char *phrase, pad; - int strict_pad, nul_term, saved_errno; + int strict_pad, saved_errno; const unsigned char *lut; ssize_t r; - /* Reserve space for NUL-termination */ - if (size) { - nul_term = 1; - size -= 1u; - } else { - nul_term = 0; - } - /* Get the prefix and hash size in `augend` and `augment` */ prefix1 = librecrypt_settings_prefix(augend, &hashsize1, ctx); prefix2 = librecrypt_settings_prefix(augment, &hashsize2, ctx); @@ -60,54 +41,31 @@ librecrypt_add_algorithm(char *out_buffer, size_t size, const char *augend, prefix2 += strlen(&augment[prefix2]); hashsize2 = 0u; } - ret = prefix1 + 1u + prefix2; - if (size) { - min = MIN(prefix1, size); - if (out_buffer != augend) - memmove(out_buffer, augend, min); - out_buffer = &out_buffer[min]; - size -= min; - if (size) { - *out_buffer++ = LIBRECRYPT_ALGORITHM_LINK_DELIMITER; - size -= 1u; - } - min = MIN(prefix2, size); - memcpy(out_buffer, augment, min); - out_buffer = &out_buffer[min]; - size -= min; - if (hashsize2) { - asterisk_len = truncated_asterisk(out_buffer, size + 1u, hashsize2); - if (ret > SIZE_MAX - asterisk_len) - abort(); /* $covered$ (impossible) */ - ret += asterisk_len; - } else { - out_buffer[0u] = '\0'; - } - } else { -#if defined(__GNUC__) -# pragma GCC diagnostic push -# pragma GCC diagnostic ignored "-Wmaybe-uninitialized" -#endif - if (!hashsize2) - goto out; -#if defined(__GNUC__) -# pragma GCC diagnostic pop -#endif - asterisk_len = measure_asterisk(hashsize2); - if (ret > SIZE_MAX - asterisk_len) + switch (concat_state.size) { + default: + librecrypt_concat_memmove_(&concat_state, augend, prefix1); + librecrypt_concat_char_no_nul_(&concat_state, LIBRECRYPT_ALGORITHM_LINK_DELIMITER); + librecrypt_concat_mem_(&concat_state, augment, prefix2); + break; + case 1u: + concat_state.buf[0u] = '\0'; + /* fall through */ + case 0u: + if (librecrypt_post_concat_adjust_(&concat_state, prefix1 + 1u + prefix2)) abort(); /* $covered$ (impossible) */ - ret += asterisk_len; - out: - if (nul_term) - out_buffer[0u] = '\0'; + break; } - if (ret > (size_t)SSIZE_MAX) { + if (hashsize2) { + librecrypt_concat_char_no_nul_(&concat_state, '*'); + librecrypt_concat_uint_(&concat_state, hashsize2); + } + if (concat_state.len > (size_t)SSIZE_MAX) { /* $covered{$ (manually) */ errno = EOVERFLOW; return -1; /* $covered}$ */ } - return (ssize_t)ret; + return (ssize_t)concat_state.len; } /* Measure size of hash size specification for `augend` */ @@ -117,13 +75,16 @@ librecrypt_add_algorithm(char *out_buffer, size_t size, const char *augend, asterisk_len = 0; } - /* Measure `augend` and '>' in output */ + /* Measure `augend`, '>', and `augment` in output */ if (prefix1 > SIZE_MAX - 1u - asterisk_len) abort(); /* $covered$ (impossible) */ - ret = prefix1 + asterisk_len + 1u; + conf_len = prefix1 + asterisk_len + 1u; + if (prefix2 > SIZE_MAX - conf_len) + abort(); /* $covered$ (impossible) */ + conf_len += prefix2; /* Decode the hash from base-64 to binary */ - if (size <= ret + prefix2) { + if (concat_state.size <= conf_len) { /* If the new hash doesn't fit, don't bother; * hash sizes are independent of password size */ phrase = NULL; @@ -155,27 +116,17 @@ librecrypt_add_algorithm(char *out_buffer, size_t size, const char *augend, } /* Chain the hash algorithms: write `augend` */ - min = MIN(prefix1, size); - if (out_buffer != augend && min) - memmove(out_buffer, augend, min); - out_buffer = &out_buffer[min]; - size -= min; - if (hashsize1 && size) { - if (truncated_asterisk(out_buffer, size + 1u, hashsize1) != asterisk_len) - abort(); /* $covered$ (impossible reliably) */ - min = MIN(asterisk_len, size); - out_buffer = &out_buffer[min]; - size -= min; + librecrypt_concat_memmove_(&concat_state, augend, prefix1); + if (hashsize1) { + librecrypt_concat_char_no_nul_(&concat_state, '*'); + librecrypt_concat_uint_(&concat_state, hashsize1); } /* Chain the hash algorithms: write '>' */ - if (size) { - *out_buffer++ = LIBRECRYPT_ALGORITHM_LINK_DELIMITER; - size -= 1u; - } + librecrypt_concat_char_no_nul_(&concat_state, LIBRECRYPT_ALGORITHM_LINK_DELIMITER); /* Chain the hash algorithms: write `augment` and hash */ - r = librecrypt_crypt(out_buffer, nul_term ? size + 1u : 0u, phrase, phraselen, augment, ctx); + r = librecrypt_crypt(concat_state.buf, concat_state.size, phrase, phraselen, augment, ctx); if (r <= 0) { saved_errno = errno; librecrypt_wipe(phrase, phraselen); @@ -185,7 +136,7 @@ librecrypt_add_algorithm(char *out_buffer, size_t size, const char *augend, errno = saved_errno; return -1; } - if (ret > (size_t)(SSIZE_MAX - r)) { + if (concat_state.len > (size_t)(SSIZE_MAX - r)) { /* $covered{$ (manually) */ librecrypt_wipe(phrase, phraselen); free(phrase); @@ -193,11 +144,11 @@ librecrypt_add_algorithm(char *out_buffer, size_t size, const char *augend, return -1; /* $covered}$ */ } - ret += (size_t)r; + concat_state.len += (size_t)r; librecrypt_wipe(phrase, phraselen); free(phrase); - return (ssize_t)ret; + return (ssize_t)concat_state.len; } |