Merge pull request #12 from tevador/pr-fix-decode

Handle seeds that can decode in multiple languages
tevador · Apr 29, 2024 · dfb05d8 · dfb05d8
2 parents 9d4f1a0 + 583cad4
commit dfb05d8
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Showing 6 changed files with 152 additions and 9 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -34,7 +34,7 @@ set_property(TARGET polyseed PROPERTY PUBLIC_HEADER include/polyseed.h)
 include_directories(polyseed
   include/)
 target_compile_definitions(polyseed PRIVATE POLYSEED_SHARED)
-set_target_properties(polyseed PROPERTIES VERSION 2.0.0
+set_target_properties(polyseed PROPERTIES VERSION 2.1.0
                                           SOVERSION 2
                                           C_STANDARD 11
                                           C_STANDARD_REQUIRED ON)

diff --git a/include/polyseed.h b/include/polyseed.h
@@ -78,6 +78,8 @@ typedef enum polyseed_status {
     POLYSEED_ERR_FORMAT = 5,
     /* Memory allocation failure */
     POLYSEED_ERR_MEMORY = 6,
+    /* Phrase matches more than one language */
+    POLYSEED_ERR_MULT_LANG = 7,
 } polyseed_status;
 
 /* Opaque struct with the seed data */
@@ -275,6 +277,24 @@ POLYSEED_API
 polyseed_status polyseed_decode(const char* str, polyseed_coin coin,
     const polyseed_lang** lang_out, polyseed_data** seed_out);
 
+/**
+ * Decodes the seed from a mnemonic phrase with a specific language.
+ * This should be used if polyseed_decode returns POLYSEED_ERR_MULT_LANG.
+ *
+ * @param str is the mnemonic phrase as a C-style string. Must not be NULL.
+ * @param coin is the coin the mnemonic phrase is intended for.
+ * @param lang is a pointer to the language to decode the seed.
+ *        Must not be NULL.
+ * @param seed_out is a pointer where the seed pointer will be stored.
+ *        Must not be NULL.
+ *
+ * @return POLYSEED_OK if the operation was successful. Other values indicate
+ *         an error (in that case, *seed_out is undefined).
+ */
+POLYSEED_API
+polyseed_status polyseed_decode_explicit(const char* str, polyseed_coin coin,
+    const polyseed_lang* lang, polyseed_data** seed_out);
+
 /**
  * Serializes the seed data in a platform-independent way.
  *

diff --git a/src/lang.c b/src/lang.c
@@ -202,10 +202,12 @@ int polyseed_lang_find_word(const polyseed_lang* lang, const char* word) {
     return lang_search(lang, word, cmp);
 }
 
-bool polyseed_phrase_decode(const polyseed_phrase phrase,
+polyseed_status polyseed_phrase_decode(const polyseed_phrase phrase,
     uint_fast16_t idx_out[POLYSEED_NUM_WORDS], const polyseed_lang** lang_out) {
-    /* Iterate through all languages and try to find one where
+    /* Iterate through all languages and try to find just one where
        all the words are a match. */
+    uint_fast16_t idx[POLYSEED_NUM_WORDS];
+    bool have_lang = false;
     for (int li = 0; li < NUM_LANGS; ++li) {
         const polyseed_lang* lang = languages[li];
         polyseed_cmp* cmp = get_comparer(lang);
@@ -217,17 +219,40 @@ bool polyseed_phrase_decode(const polyseed_phrase phrase,
                 success = false;
                 break;
             }
-            idx_out[wi] = value;
+            idx[wi] = value;
         }
         if (!success) {
             continue;
         }
+        if (have_lang) {
+            /* The phrase can decode in multiple languages.
+            Use polyseed_phrase_decode_explicit. */
+            return POLYSEED_ERR_MULT_LANG;
+        }
+        have_lang = true;
+        for (int wi = 0; wi < POLYSEED_NUM_WORDS; ++wi) {
+            idx_out[wi] = idx[wi];
+        }
         if (lang_out != NULL) {
             *lang_out = lang;
         }
-        return true;
     }
-    return false;
+    return have_lang ? POLYSEED_OK : POLYSEED_ERR_LANG;
+}
+
+polyseed_status polyseed_phrase_decode_explicit(const polyseed_phrase phrase,
+    const polyseed_lang* lang, uint_fast16_t idx_out[POLYSEED_NUM_WORDS]) {
+
+    polyseed_cmp* cmp = get_comparer(lang);
+    for (int wi = 0; wi < POLYSEED_NUM_WORDS; ++wi) {
+        const char* word = phrase[wi];
+        int value = lang_search(lang, word, cmp);
+        if (value < 0) {
+            return POLYSEED_ERR_LANG;
+        }
+        idx_out[wi] = value;
+    }
+    return POLYSEED_OK;
 }
 
 void polyseed_lang_check(const polyseed_lang* lang) {

diff --git a/src/lang.h b/src/lang.h
@@ -26,9 +26,12 @@ typedef const char* polyseed_phrase[POLYSEED_NUM_WORDS];
 POLYSEED_PRIVATE int polyseed_lang_find_word(const polyseed_lang* lang,
     const char* word);
 
-POLYSEED_PRIVATE bool polyseed_phrase_decode(const polyseed_phrase phrase,
+POLYSEED_PRIVATE polyseed_status polyseed_phrase_decode(const polyseed_phrase phrase,
     uint_fast16_t idx_out[POLYSEED_NUM_WORDS], const polyseed_lang** lang_out);
 
+POLYSEED_PRIVATE polyseed_status polyseed_phrase_decode_explicit(const polyseed_phrase phrase,
+    const polyseed_lang* lang, uint_fast16_t idx_out[POLYSEED_NUM_WORDS]);
+
 POLYSEED_PRIVATE void polyseed_lang_check(const polyseed_lang* lang);
 
 #endif
diff --git a/src/polyseed.c b/src/polyseed.c
@@ -183,8 +183,78 @@ polyseed_status polyseed_decode(const char* str, polyseed_coin coin,
     }
 
     /* decode words into polynomial coefficients */
-    if (!polyseed_phrase_decode(words, poly.coeff, lang_out)) {
-        res = POLYSEED_ERR_LANG;
+    res = polyseed_phrase_decode(words, poly.coeff, lang_out);
+
+    if (res != POLYSEED_OK) {
+        goto cleanup;
+    }
+
+    /* finalize polynomial */
+    poly.coeff[POLY_NUM_CHECK_DIGITS] ^= coin;
+
+    /* checksum */
+    if (!gf_poly_check(&poly)) {
+        res = POLYSEED_ERR_CHECKSUM;
+        goto cleanup;
+    }
+
+    /* alocate memory */
+    seed = ALLOC(sizeof(polyseed_data));
+
+    if (seed == NULL) {
+        res = POLYSEED_ERR_MEMORY;
+        goto cleanup;
+    }
+
+    /* decode polynomial into seed data */
+    polyseed_poly_to_data(&poly, seed);
+
+    /* check features */
+    if (!polyseed_features_supported(seed->features)) {
+        polyseed_free(seed);
+        res = POLYSEED_ERR_UNSUPPORTED;
+        goto cleanup;
+    }
+
+    *seed_out = seed;
+    res = POLYSEED_OK;
+
+cleanup:
+    MEMZERO_LOC(str_tmp);
+    MEMZERO_LOC(words);
+    MEMZERO_LOC(poly);
+    return res;
+}
+
+polyseed_status polyseed_decode_explicit(const char* str, polyseed_coin coin,
+    const polyseed_lang* lang, polyseed_data** seed_out) {
+
+    assert(str != NULL);
+    assert((gf_elem)coin < GF_SIZE);
+    assert(lang != NULL);
+    assert(seed_out != NULL);
+    CHECK_DEPS();
+
+    polyseed_str str_tmp;
+    polyseed_phrase words;
+    gf_poly poly = { 0 };
+    polyseed_status res;
+    polyseed_data* seed;
+
+    /* canonical decomposition */
+    size_t str_size = UTF8_DECOMPOSE(str, str_tmp);
+    assert(str_size < POLYSEED_STR_SIZE);
+
+    /* split into words */
+    if (str_split(str_tmp, words) != POLYSEED_NUM_WORDS) {
+        res = POLYSEED_ERR_NUM_WORDS;
+        goto cleanup;
+    }
+
+    /* decode words into polynomial coefficients */
+    res = polyseed_phrase_decode_explicit(words, lang, poly.coeff);
+
+    if (res != POLYSEED_OK) {
         goto cleanup;
     }
 

diff --git a/tests/tests.c b/tests/tests.c
@@ -71,6 +71,10 @@ static const char* g_phrase_es5 =
     "eje fin part cele tab pest lien puma "
     "pris hora rega leng exis lapi lote sono";
 
+static const char* g_phrase_es_mult =
+    "impo sort usua cabi venu nobl oliv clim "
+    "cont barr marc auto prod vaca torn fati";
+
 static const char* g_phrase_garbage1 = "xxx xxx";
 
 static const char* g_phrase_garbage2 =
@@ -662,6 +666,25 @@ static bool test_decode_es_prefix2(void) {
     return true;
 }
 
+static bool test_decode_es_mult1(void) {
+    const polyseed_lang* lang;
+    polyseed_data* seed;
+    polyseed_status res = polyseed_decode(g_phrase_es_mult, POLYSEED_MONERO, &lang, &seed);
+    assert(res == POLYSEED_ERR_MULT_LANG);
+    return true;
+}
+
+static bool test_decode_es_mult2(void) {
+    if (g_lang_es == NULL) {
+        return false;
+    }
+    polyseed_data* seed;
+    polyseed_status res = polyseed_decode_explicit(g_phrase_es_mult, POLYSEED_MONERO, g_lang_es, &seed);
+    assert(res == POLYSEED_OK);
+    polyseed_free(seed);
+    return true;
+}
+
 static bool test_free2(void) {
     polyseed_free(g_seed2);
     return true;
@@ -863,6 +886,8 @@ int main() {
     RUN_TEST(test_decode_es_prefix1);
     RUN_TEST(test_decode_es_suffix);
     RUN_TEST(test_decode_es_prefix2);
+    RUN_TEST(test_decode_es_mult1);
+    RUN_TEST(test_decode_es_mult2);
     RUN_TEST(test_free2);
     RUN_TEST(test_inject3);
     RUN_TEST(test_features3a);