Move to shared libmincrypt
Remove mincrypt source from TWRP and add rule to make
libmincrypt as a shared library.
No more crashes during zip signature verification and
less code to maintain in TWRP.
diff --git a/twinstall.cpp b/twinstall.cpp
index 967528e..af53256 100644
--- a/twinstall.cpp
+++ b/twinstall.cpp
@@ -26,8 +26,8 @@
#include <stdio.h>
#include "common.h"
-#include "twmincrypt/twrsa.h"
-#include "twmincrypt/twsha.h"
+#include "mincrypt/rsa.h"
+#include "mincrypt/sha.h"
#include "minui/minui.h"
#include "minzip/SysUtil.h"
#include "minzip/Zip.h"
@@ -59,165 +59,6 @@
enum { INSTALL_SUCCESS, INSTALL_ERROR, INSTALL_CORRUPT };
-// Look for an RSA signature embedded in the .ZIP file comment given
-// the path to the zip. Verify it matches one of the given public
-// keys.
-//
-// Return VERIFY_SUCCESS, VERIFY_FAILURE (if any error is encountered
-// or no key matches the signature).
-
-int TWverify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKeys) {
- ui->SetProgress(0.0);
-
- FILE* f = fopen(path, "rb");
- if (f == NULL) {
- LOGE("failed to open %s (%s)\n", path, strerror(errno));
- return VERIFY_FAILURE;
- }
-
- // An archive with a whole-file signature will end in six bytes:
- //
- // (2-byte signature start) $ff $ff (2-byte comment size)
- //
- // (As far as the ZIP format is concerned, these are part of the
- // archive comment.) We start by reading this footer, this tells
- // us how far back from the end we have to start reading to find
- // the whole comment.
-
-#define FOOTER_SIZE 6
-
- if (fseek(f, -FOOTER_SIZE, SEEK_END) != 0) {
- LOGE("failed to seek in %s (%s)\n", path, strerror(errno));
- fclose(f);
- return VERIFY_FAILURE;
- }
-
- unsigned char footer[FOOTER_SIZE];
- if (fread(footer, 1, FOOTER_SIZE, f) != FOOTER_SIZE) {
- LOGE("failed to read footer from %s (%s)\n", path, strerror(errno));
- fclose(f);
- return VERIFY_FAILURE;
- }
-
- if (footer[2] != 0xff || footer[3] != 0xff) {
- fclose(f);
- return VERIFY_FAILURE;
- }
-
- size_t comment_size = footer[4] + (footer[5] << 8);
- size_t signature_start = footer[0] + (footer[1] << 8);
- LOGI("comment is %d bytes; signature %d bytes from end\n",
- comment_size, signature_start);
-
- if (signature_start - FOOTER_SIZE < RSANUMBYTES) {
- // "signature" block isn't big enough to contain an RSA block.
- LOGE("signature is too short\n");
- fclose(f);
- return VERIFY_FAILURE;
- }
-
-#define EOCD_HEADER_SIZE 22
-
- // The end-of-central-directory record is 22 bytes plus any
- // comment length.
- size_t eocd_size = comment_size + EOCD_HEADER_SIZE;
-
- if (fseek(f, -eocd_size, SEEK_END) != 0) {
- LOGE("failed to seek in %s (%s)\n", path, strerror(errno));
- fclose(f);
- return VERIFY_FAILURE;
- }
-
- // Determine how much of the file is covered by the signature.
- // This is everything except the signature data and length, which
- // includes all of the EOCD except for the comment length field (2
- // bytes) and the comment data.
- size_t signed_len = ftell(f) + EOCD_HEADER_SIZE - 2;
-
- unsigned char* eocd = (unsigned char*)malloc(eocd_size);
- if (eocd == NULL) {
- LOGE("malloc for EOCD record failed\n");
- fclose(f);
- return VERIFY_FAILURE;
- }
- if (fread(eocd, 1, eocd_size, f) != eocd_size) {
- LOGE("failed to read eocd from %s (%s)\n", path, strerror(errno));
- fclose(f);
- return VERIFY_FAILURE;
- }
-
- // If this is really is the EOCD record, it will begin with the
- // magic number $50 $4b $05 $06.
- if (eocd[0] != 0x50 || eocd[1] != 0x4b ||
- eocd[2] != 0x05 || eocd[3] != 0x06) {
- LOGE("signature length doesn't match EOCD marker\n");
- fclose(f);
- return VERIFY_FAILURE;
- }
-
- size_t i;
- for (i = 4; i < eocd_size-3; ++i) {
- if (eocd[i ] == 0x50 && eocd[i+1] == 0x4b &&
- eocd[i+2] == 0x05 && eocd[i+3] == 0x06) {
- // if the sequence $50 $4b $05 $06 appears anywhere after
- // the real one, minzip will find the later (wrong) one,
- // which could be exploitable. Fail verification if
- // this sequence occurs anywhere after the real one.
- LOGE("EOCD marker occurs after start of EOCD\n");
- fclose(f);
- return VERIFY_FAILURE;
- }
- }
-
-#define BUFFER_SIZE 4096
-
- SHA_CTX ctx;
- SHA_init(&ctx);
- unsigned char* buffer = (unsigned char*)malloc(BUFFER_SIZE);
- if (buffer == NULL) {
- LOGE("failed to alloc memory for sha1 buffer\n");
- fclose(f);
- return VERIFY_FAILURE;
- }
-
- double frac = -1.0;
- size_t so_far = 0;
- fseek(f, 0, SEEK_SET);
- while (so_far < signed_len) {
- size_t size = BUFFER_SIZE;
- if (signed_len - so_far < size) size = signed_len - so_far;
- if (fread(buffer, 1, size, f) != size) {
- LOGE("failed to read data from %s (%s)\n", path, strerror(errno));
- fclose(f);
- return VERIFY_FAILURE;
- }
- SHA_update(&ctx, buffer, size);
- so_far += size;
- double f = so_far / (double)signed_len;
- if (f > frac + 0.02 || size == so_far) {
- ui->SetProgress(f);
- frac = f;
- }
- }
- fclose(f);
- free(buffer);
-
- const uint8_t* sha1 = SHA_final(&ctx);
- for (i = 0; i < numKeys; ++i) {
- // The 6 bytes is the "(signature_start) $ff $ff (comment_size)" that
- // the signing tool appends after the signature itself.
- if (RSA_verify(pKeys+i, eocd + eocd_size - 6 - RSANUMBYTES,
- RSANUMBYTES, sha1)) {
- LOGI("whole-file signature verified against key %d\n", i);
- free(eocd);
- return VERIFY_SUCCESS;
- }
- }
- free(eocd);
- LOGE("failed to verify whole-file signature\n");
- return VERIFY_FAILURE;
-}
-
// If the package contains an update binary, extract it and run it.
static int
try_update_binary(const char *path, ZipArchive *zip, int* wipe_cache) {
@@ -466,7 +307,7 @@
ui->SetProgressType(RecoveryUI::DETERMINATE);
ui->ShowProgress(VERIFICATION_PROGRESS_FRACTION, VERIFICATION_PROGRESS_TIME);
- err = TWverify_file(path, loadedKeys, numKeys);
+ err = verify_file(path, loadedKeys, numKeys);
free(loadedKeys);
LOGI("verify_file returned %d\n", err);
if (err != VERIFY_SUCCESS) {