diff options
| -rw-r--r-- | src/package.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/src/package.c b/src/package.c index 3b7c6bd..01ae3aa 100644 --- a/src/package.c +++ b/src/package.c @@ -474,9 +474,14 @@ void apk_sign_ctx_init(struct apk_sign_ctx *ctx, int action, ctx->action = action; switch (action) { case APK_SIGN_VERIFY: + /* If we're only verifing, we're going to start with a + * signature section, which we don't need a hash of */ ctx->md = EVP_md_null(); break; case APK_SIGN_VERIFY_IDENTITY: + /* If we're checking the package against a particular hash, + * we need to start with that hash, because there may not + * be a signature section to deduce it from */ ctx->md = EVP_sha1(); memcpy(&ctx->identity, identity, sizeof(ctx->identity)); break; @@ -566,10 +571,10 @@ int apk_sign_ctx_process_file(struct apk_sign_ctx *ctx, return 1; } - /* A signature file */ + /* By this point, we must be handling a signature file */ ctx->num_signatures++; - /* Found already a trusted key */ + /* Already found a signature by a trusted key; no need to keep searching */ if ((ctx->action != APK_SIGN_VERIFY && ctx->action != APK_SIGN_VERIFY_AND_GENERATE) || ctx->signature.pkey != NULL) @@ -645,6 +650,12 @@ int apk_sign_ctx_verify_tar(void *sctx, const struct apk_file_info *fi, return 0; } +/* apk_sign_ctx_mpart_cb() handles hashing archives and checking signatures, but + it can't do it alone. apk_sign_ctx_process_file() must be in the loop to + actually select which signature is to be verified and load the corresponding + public key into the context object, and apk_sign_ctx_parse_pkginfo_line() + needs to be called when handling the .PKGINFO file to find any applicable + datahash and load it into the context for this function to check against. */ int apk_sign_ctx_mpart_cb(void *ctx, int part, apk_blob_t data) { struct apk_sign_ctx *sctx = (struct apk_sign_ctx *) ctx; @@ -671,14 +682,12 @@ int apk_sign_ctx_mpart_cb(void *ctx, int part, apk_blob_t data) part != APK_MPART_END) goto update_digest; - /* Drool in the remaining of the digest block now, we will finish - * it on all cases */ + /* Drool in the remainder of the digest block now, we will finish + * hashing it in all cases */ EVP_DigestUpdate(sctx->mdctx, data.ptr, data.len); - /* End of control-block and checking control hash/signature or - * end of data-block and checking its hash/signature */ if (sctx->has_data_checksum && !end_of_control) { - /* End of control-block and check it's hash */ + /* End of data-block with a checksum read from the control block */ EVP_DigestFinal_ex(sctx->mdctx, calculated, NULL); if (EVP_MD_CTX_size(sctx->mdctx) == 0 || memcmp(calculated, sctx->data_checksum, @@ -691,6 +700,9 @@ int apk_sign_ctx_mpart_cb(void *ctx, int part, apk_blob_t data) return 0; } + /* Either end of control block with a data checksum or end + * of the data block following a control block without a data + * checksum. In either case, we're checking a signature. */ r = check_signing_key_trust(sctx); if (r < 0) return r; |