query properties (thx @DanyL)

img4.c

@@ -369,6 +369,7 @@ usage(const char *argv0)
     printf("    -g <file>       write keybag to <file>\n");
     printf("    -m <file>       write ticket to <file>\n");
     printf("    -c <info>       check signature with <info>\n");
+    printf("    -q <prop>       query property\n");
     printf("    -f              check hash against manifest\n");
     printf("    -n              print nonce\n");
     printf("    -b              print kbags\n");
@@ -404,6 +405,7 @@ main(int argc, char **argv)
     const char *ename = NULL;
     const char *gname = NULL;
     const char *mname = NULL;
+    const char *query = NULL;
     char *cinfo = NULL;
     int get_nonce = 0;
     int get_kbags = 0;
@@ -484,6 +486,8 @@ main(int argc, char **argv)
                 if (argc >= 2) { mname = *++argv; argc--; continue; }
             case 'c':
                 if (argc >= 2) { cinfo = *++argv; argc--; continue; }
+            case 'q':
+                if (argc >= 2) { query = *++argv; argc--; continue; }
             case 'T':
                 if (argc >= 2) { set_type = *++argv; argc--; continue; }
             case 'P':
@@ -569,7 +573,7 @@ main(int argc, char **argv)
         fd->close(fd);
         return -1;
     }
-    if (!get_nonce && !get_kbags && !get_version) {
+    if (!get_nonce && !get_kbags && !get_version && !query) {
         printf("%c%c%c%c\n", FOURCC(type));
     }
 
@@ -609,6 +613,20 @@ main(int argc, char **argv)
         }
         rc |= rv;
     }
+    if (query) {
+        unsigned char result[256];
+        unsigned int i, len = sizeof(result);
+        rv = fd->ioctl(fd, IOCTL_IMG4_QUERY_PROP, query, result, &len);
+        if (rv) {
+            fprintf(stderr, "[e] query failed\n");
+        } else {
+            for (i = 0; i < len; i++) {
+                printf("%02x", result[i]);
+            }
+            printf("\n");
+        }
+        rc |= rv;
+    }
     if (get_nonce) {
         uint64_t nonce = 0;
         rv = fd->ioctl(fd, IOCTL_IMG4_GET_NONCE, &nonce);

libvfs/vfs.h

@@ -37,6 +37,7 @@ struct file_ops {
 #define IOCTL_IMG4_SET_KEYBAG2  69	/* (unsigned char[48], unsigned char[48]) */
 #define IOCTL_IMG4_GET_VERSION  70	/* (void **, size_t *) */
 #define IOCTL_IMG4_SET_VERSION  71	/* (void *, size_t) */
+#define IOCTL_IMG4_QUERY_PROP   80	/* (const char *, unsigned char *, unsigned int *) */
 #define IOCTL_IMG4_EVAL_TRUST   90	/* (void *) */
 
 #define FLAG_IMG4_SKIP_DECOMPRESSION    (1 << 0)

libvfs/vfs_img4.c

@@ -1437,6 +1437,74 @@ image4_validate_property_callback(DERTag tag, DERItem *b, DictType what, void *c
     return 0;
 }
 
+static int
+query_property_callback(DERTag tag, DERItem *b, DictType what, void *ctx)
+{
+    int rv;
+    DERMonster *tmp = (DERMonster *)ctx;
+    if ((unsigned int)tag != tmp->tag) {
+        return 0;
+    }
+    // thx @DanyL
+    switch ((unsigned int)tag) {
+        case 'AMNM':
+        case 'CPRO':
+        case 'CSEC':
+        case 'DPRO':
+        case 'EKEY':
+        case 'EPRO':
+        case 'ESEC': {
+            bool value;
+            rv = Img4DecodeGetPropertyBoolean(b, tag, &value);
+            if (rv) {
+                return rv;
+            }
+            if (tmp->item.length < sizeof(bool)) {
+                return -1;
+            }
+            tmp->item.length = sizeof(bool);
+            *(bool *)tmp->item.data = value;
+            tmp->tag = 0;
+            break;
+        }
+        case 'BORD':
+        case 'CEPO':
+        case 'CHIP':
+        case 'ECID':
+        case 'SDOM': {
+            uint64_t value;
+            rv = Img4DecodeGetPropertyInteger64(b, tag, &value);
+            if (rv) {
+                return rv;
+            }
+            if (tmp->item.length < sizeof(uint64_t)) {
+                return -1;
+            }
+            tmp->item.length = sizeof(uint64_t);
+            *(uint64_t *)tmp->item.data = value;
+            tmp->tag = 0;
+            break;
+        }
+        case 'BNCH':
+        case 'DGST': {
+            DERByte *data;
+            DERSize length;
+            rv = Img4DecodeGetPropertyData(b, tag, &data, &length);
+            if (rv) {
+                return rv;
+            }
+            if (tmp->item.length < length) {
+                return -1;
+            }
+            tmp->item.length = length;
+            memmove(tmp->item.data, data, length);
+            tmp->tag = 0;
+            break;
+        }
+    }
+    return 0;
+}
+
 static int
 hash_property_callback(DERTag tag, DERItem *b, DictType what, void *ctx)
 {
@@ -2263,6 +2331,38 @@ img4_ioctl(FHANDLE fd, unsigned long req, ...)
             ctx->dirty = 1;
             break;
         }
+        case IOCTL_IMG4_QUERY_PROP: {
+            const char *prop = va_arg(ap, char *);
+            unsigned char *out = va_arg(ap, unsigned char *);
+            unsigned int *len = va_arg(ap, unsigned int *);
+            unsigned int fourcc;
+            TheImg4Manifest m;
+            DERMonster tmp;
+            for (fourcc = 0; *prop; prop++) {
+                fourcc = (fourcc << 8) | *prop;
+            }
+            if (!fourcc) {
+                rv = -1;
+                break;
+            }
+            rv = DERImg4DecodeManifest(&ctx->manifest, &m);
+            if (rv) {
+                break;
+            }
+            tmp.item.data = out;
+            tmp.item.length = *len;
+            tmp.tag = fourcc;
+            rv = walkman(&m, ctx->type, query_property_callback, &tmp);
+            if (rv) {
+                break;
+            }
+            if (tmp.tag) {
+                rv = -1;
+                break;
+            }
+            *len = tmp.item.length;
+            break;
+        }
         case IOCTL_ENC_SET_NOENC: if (fd->flags == O_RDONLY) break; else {
             FHANDLE pfd = ctx->pfd;
             pfd->ioctl(pfd, req); /* may fail if enc is just a pass-through */