Merge `signal-protocol` into `omemo` plugin

Same reasoning as for the `openpgp` plugin.

1 files changed, 377 insertions, 0 deletions

diff --git a/plugins/omemo/src/signal/signal_helper.c b/plugins/omemo/src/signal/signal_helper.c
new file mode 100644
index 00000000..17682929
--- /dev/null
+++ b/plugins/omemo/src/signal/signal_helper.c
@@ -0,0 +1,377 @@
+#include "signal_helper.h"
+
+#include <gcrypt.h>
+
+signal_type_base* signal_type_ref_vapi(void* instance) {
+    g_return_val_if_fail(instance != NULL, NULL);
+    signal_type_ref(instance);
+    return instance;
+}
+
+signal_type_base* signal_type_unref_vapi(void* instance) {
+    g_return_val_if_fail(instance != NULL, NULL);
+    signal_type_unref(instance);
+    return NULL;
+}
+
+signal_protocol_address* signal_protocol_address_new(const gchar* name, int32_t device_id) {
+    g_return_val_if_fail(name != NULL, NULL);
+    signal_protocol_address* address = malloc(sizeof(signal_protocol_address));
+    address->device_id = -1;
+    address->name = NULL;
+    signal_protocol_address_set_name(address, name);
+    signal_protocol_address_set_device_id(address, device_id);
+    return address;
+}
+
+void signal_protocol_address_free(signal_protocol_address* ptr) {
+    g_return_if_fail(ptr != NULL);
+    if (ptr->name) {
+        g_free((void*)ptr->name);
+    }
+    return free(ptr);
+}
+
+void signal_protocol_address_set_name(signal_protocol_address* self, const gchar* name) {
+    g_return_if_fail(self != NULL);
+    g_return_if_fail(name != NULL);
+    gchar* n = g_malloc(strlen(name)+1);
+    memcpy(n, name, strlen(name));
+    n[strlen(name)] = 0;
+    if (self->name) {
+        g_free((void*)self->name);
+    }
+    self->name = n;
+    self->name_len = strlen(n);
+}
+
+gchar* signal_protocol_address_get_name(signal_protocol_address* self) {
+    g_return_val_if_fail(self != NULL, NULL);
+    g_return_val_if_fail(self->name != NULL, 0);
+    gchar* res = g_malloc(sizeof(char) * (self->name_len + 1));
+    memcpy(res, self->name, self->name_len);
+    res[self->name_len] = 0;
+    return res;
+}
+
+int32_t signal_protocol_address_get_device_id(signal_protocol_address* self) {
+    g_return_val_if_fail(self != NULL, -1);
+    return self->device_id;
+}
+
+void signal_protocol_address_set_device_id(signal_protocol_address* self, int32_t device_id) {
+    g_return_if_fail(self != NULL);
+    self->device_id = device_id;
+}
+
+int signal_vala_randomize(uint8_t *data, size_t len) {
+    gcry_randomize(data, len, GCRY_STRONG_RANDOM);
+    return SG_SUCCESS;
+}
+
+int signal_vala_random_generator(uint8_t *data, size_t len, void *user_data) {
+    gcry_randomize(data, len, GCRY_STRONG_RANDOM);
+    return SG_SUCCESS;
+}
+
+int signal_vala_hmac_sha256_init(void **hmac_context, const uint8_t *key, size_t key_len, void *user_data) {
+    gcry_mac_hd_t* ctx = malloc(sizeof(gcry_mac_hd_t));
+    if (!ctx) return SG_ERR_NOMEM;
+
+    if (gcry_mac_open(ctx, GCRY_MAC_HMAC_SHA256, 0, 0)) {
+        free(ctx);
+        return SG_ERR_UNKNOWN;
+    }
+
+    if (gcry_mac_setkey(*ctx, key, key_len)) {
+        free(ctx);
+        return SG_ERR_UNKNOWN;
+    }
+
+    *hmac_context = ctx;
+
+    return SG_SUCCESS;
+}
+
+int signal_vala_hmac_sha256_update(void *hmac_context, const uint8_t *data, size_t data_len, void *user_data) {
+    gcry_mac_hd_t* ctx = hmac_context;
+
+    if (gcry_mac_write(*ctx, data, data_len)) return SG_ERR_UNKNOWN;
+
+    return SG_SUCCESS;
+}
+
+int signal_vala_hmac_sha256_final(void *hmac_context, signal_buffer **output, void *user_data) {
+    size_t len = gcry_mac_get_algo_maclen(GCRY_MAC_HMAC_SHA256);
+    uint8_t md[len];
+    gcry_mac_hd_t* ctx = hmac_context;
+
+    if (gcry_mac_read(*ctx, md, &len)) return SG_ERR_UNKNOWN;
+
+    signal_buffer *output_buffer = signal_buffer_create(md, len);
+    if (!output_buffer) return SG_ERR_NOMEM;
+
+    *output = output_buffer;
+
+    return SG_SUCCESS;
+}
+
+void signal_vala_hmac_sha256_cleanup(void *hmac_context, void *user_data) {
+    gcry_mac_hd_t* ctx = hmac_context;
+    if (ctx) {
+        gcry_mac_close(*ctx);
+        free(ctx);
+    }
+}
+
+int signal_vala_sha512_digest_init(void **digest_context, void *user_data) {
+    gcry_md_hd_t* ctx = malloc(sizeof(gcry_mac_hd_t));
+    if (!ctx) return SG_ERR_NOMEM;
+
+    if (gcry_md_open(ctx, GCRY_MD_SHA512, 0)) {
+        free(ctx);
+        return SG_ERR_UNKNOWN;
+    }
+
+    *digest_context = ctx;
+
+    return SG_SUCCESS;
+}
+
+int signal_vala_sha512_digest_update(void *digest_context, const uint8_t *data, size_t data_len, void *user_data) {
+    gcry_md_hd_t* ctx = digest_context;
+
+    gcry_md_write(*ctx, data, data_len);
+
+    return SG_SUCCESS;
+}
+
+int signal_vala_sha512_digest_final(void *digest_context, signal_buffer **output, void *user_data) {
+    size_t len = gcry_md_get_algo_dlen(GCRY_MD_SHA512);
+    gcry_md_hd_t* ctx = digest_context;
+
+    uint8_t* md = gcry_md_read(*ctx, GCRY_MD_SHA512);
+    if (!md) return SG_ERR_UNKNOWN;
+
+    gcry_md_reset(*ctx);
+
+    signal_buffer *output_buffer = signal_buffer_create(md, len);
+    free(md);
+    if (!output_buffer) return SG_ERR_NOMEM;
+
+    *output = output_buffer;
+
+    return SG_SUCCESS;
+}
+
+void signal_vala_sha512_digest_cleanup(void *digest_context, void *user_data) {
+    gcry_md_hd_t* ctx = digest_context;
+    if (ctx) {
+        gcry_md_close(*ctx);
+        free(ctx);
+    }
+}
+
+const int aes_cipher(int cipher, size_t key_len, int* algo, int* mode) {
+    switch (key_len) {
+        case 16:
+            *algo = GCRY_CIPHER_AES128;
+            break;
+        case 24:
+            *algo = GCRY_CIPHER_AES192;
+            break;
+        case 32:
+            *algo = GCRY_CIPHER_AES256;
+            break;
+        default:
+            return SG_ERR_UNKNOWN;
+    }
+    switch (cipher) {
+        case SG_CIPHER_AES_CBC_PKCS5:
+            *mode = GCRY_CIPHER_MODE_CBC;
+            break;
+        case SG_CIPHER_AES_CTR_NOPADDING:
+            *mode = GCRY_CIPHER_MODE_CTR;
+            break;
+        case SG_CIPHER_AES_GCM_NOPADDING:
+            *mode = GCRY_CIPHER_MODE_GCM;
+            break;
+        default:
+            return SG_ERR_UNKNOWN;
+    }
+    return SG_SUCCESS;
+}
+
+int signal_vala_encrypt(signal_buffer **output,
+        int cipher,
+        const uint8_t *key, size_t key_len,
+        const uint8_t *iv, size_t iv_len,
+        const uint8_t *plaintext, size_t plaintext_len,
+        void *user_data) {
+    int algo, mode, error_code = SG_ERR_UNKNOWN;
+    if (aes_cipher(cipher, key_len, &algo, &mode)) return SG_ERR_INVAL;
+
+    gcry_cipher_hd_t ctx = {0};
+
+    if (gcry_cipher_open(&ctx, algo, mode, 0)) return SG_ERR_NOMEM;
+
+    signal_buffer* padded = 0;
+    signal_buffer* out_buf = 0;
+    goto no_error;
+error:
+    gcry_cipher_close(ctx);
+    if (padded != 0) {
+        signal_buffer_bzero_free(padded);
+    }
+    if (out_buf != 0) {
+        signal_buffer_free(out_buf);
+    }
+    return error_code;
+no_error:
+
+    if (gcry_cipher_setkey(ctx, key, key_len)) goto error;
+
+    uint8_t tag_len = 0, pad_len = 0;
+    switch (cipher) {
+        case SG_CIPHER_AES_CBC_PKCS5:
+            if (gcry_cipher_setiv(ctx, iv, iv_len)) goto error;
+            pad_len = 16 - (plaintext_len % 16);
+            if (pad_len == 0) pad_len = 16;
+            break;
+        case SG_CIPHER_AES_CTR_NOPADDING:
+            if (gcry_cipher_setctr(ctx, iv, iv_len)) goto error;
+            break;
+        case SG_CIPHER_AES_GCM_NOPADDING:
+            if (gcry_cipher_setiv(ctx, iv, iv_len)) goto error;
+            tag_len = 16;
+            break;
+        default:
+            return SG_ERR_UNKNOWN;
+    }
+
+    size_t padded_len = plaintext_len + pad_len;
+    padded = signal_buffer_alloc(padded_len);
+    if (padded == 0) {
+        error_code = SG_ERR_NOMEM;
+        goto error;
+    }
+
+    memset(signal_buffer_data(padded) + plaintext_len, pad_len, pad_len);
+    memcpy(signal_buffer_data(padded), plaintext, plaintext_len);
+
+    out_buf = signal_buffer_alloc(padded_len + tag_len);
+    if (out_buf == 0) {
+        error_code = SG_ERR_NOMEM;
+        goto error;
+    }
+
+    if (gcry_cipher_encrypt(ctx, signal_buffer_data(out_buf), padded_len, signal_buffer_data(padded), padded_len)) goto error;
+
+    if (tag_len > 0) {
+        if (gcry_cipher_gettag(ctx, signal_buffer_data(out_buf) + padded_len, tag_len)) goto error;
+    }
+
+    *output = out_buf;
+    out_buf = 0;
+
+    signal_buffer_bzero_free(padded);
+    padded = 0;
+
+    gcry_cipher_close(ctx);
+    return SG_SUCCESS;
+}
+
+int signal_vala_decrypt(signal_buffer **output,
+        int cipher,
+        const uint8_t *key, size_t key_len,
+        const uint8_t *iv, size_t iv_len,
+        const uint8_t *ciphertext, size_t ciphertext_len,
+        void *user_data) {
+    int algo, mode, error_code = SG_ERR_UNKNOWN;
+    *output = 0;
+    if (aes_cipher(cipher, key_len, &algo, &mode)) return SG_ERR_INVAL;
+    if (ciphertext_len == 0) return SG_ERR_INVAL;
+
+    gcry_cipher_hd_t ctx = {0};
+
+    if (gcry_cipher_open(&ctx, algo, mode, 0)) return SG_ERR_NOMEM;
+
+    signal_buffer* out_buf = 0;
+    goto no_error;
+error:
+    gcry_cipher_close(ctx);
+    if (out_buf != 0) {
+        signal_buffer_bzero_free(out_buf);
+    }
+    return error_code;
+no_error:
+
+    if (gcry_cipher_setkey(ctx, key, key_len)) goto error;
+
+    uint8_t tag_len = 0, pkcs_pad = FALSE;
+    switch (cipher) {
+        case SG_CIPHER_AES_CBC_PKCS5:
+            if (gcry_cipher_setiv(ctx, iv, iv_len)) goto error;
+            pkcs_pad = TRUE;
+            break;
+        case SG_CIPHER_AES_CTR_NOPADDING:
+            if (gcry_cipher_setctr(ctx, iv, iv_len)) goto error;
+            break;
+        case SG_CIPHER_AES_GCM_NOPADDING:
+            if (gcry_cipher_setiv(ctx, iv, iv_len)) goto error;
+            if (ciphertext_len < 16) goto error;
+            tag_len = 16;
+            break;
+        default:
+            goto error;
+    }
+
+    size_t padded_len = ciphertext_len - tag_len;
+    out_buf = signal_buffer_alloc(padded_len);
+    if (out_buf == 0) {
+        error_code = SG_ERR_NOMEM;
+        goto error;
+    }
+
+    if (gcry_cipher_decrypt(ctx, signal_buffer_data(out_buf), signal_buffer_len(out_buf), ciphertext, padded_len)) goto error;
+
+    if (tag_len > 0) {
+        if (gcry_cipher_checktag(ctx, ciphertext + padded_len, tag_len)) goto error;
+    }
+
+    if (pkcs_pad) {
+        uint8_t pad_len = signal_buffer_data(out_buf)[padded_len - 1];
+        if (pad_len > 16 || pad_len > padded_len) goto error;
+        *output = signal_buffer_create(signal_buffer_data(out_buf), padded_len - pad_len);
+        signal_buffer_bzero_free(out_buf);
+        out_buf = 0;
+    } else {
+        *output = out_buf;
+        out_buf = 0;
+    }
+
+    gcry_cipher_close(ctx);
+    return SG_SUCCESS;
+}
+
+void setup_signal_vala_crypto_provider(signal_context *context)
+{
+    gcry_check_version(NULL);
+
+    signal_crypto_provider provider = {
+            .random_func = signal_vala_random_generator,
+            .hmac_sha256_init_func = signal_vala_hmac_sha256_init,
+            .hmac_sha256_update_func = signal_vala_hmac_sha256_update,
+            .hmac_sha256_final_func = signal_vala_hmac_sha256_final,
+            .hmac_sha256_cleanup_func = signal_vala_hmac_sha256_cleanup,
+            .sha512_digest_init_func = signal_vala_sha512_digest_init,
+            .sha512_digest_update_func = signal_vala_sha512_digest_update,
+            .sha512_digest_final_func = signal_vala_sha512_digest_final,
+            .sha512_digest_cleanup_func = signal_vala_sha512_digest_cleanup,
+            .encrypt_func = signal_vala_encrypt,
+            .decrypt_func = signal_vala_decrypt,
+            .user_data = 0
+    };
+
+    signal_context_set_crypto_provider(context, &provider);
+}