(PemCodec) Cleanup.

1 files changed, 70 insertions, 62 deletions

diff --git a/src/main/c/foo/PemCodec.c b/src/main/c/foo/PemCodec.c
index c797610..79f486e 100644
--- a/src/main/c/foo/PemCodec.c
+++ b/src/main/c/foo/PemCodec.c
@@ -1,17 +1,3 @@
-/*
-
-TODO move to some kind of makefile
-
-  true \
-    && CFLAGS="-Wall -std=c99 -Werror -fmax-errors=3" \
-    && `# CFLAGS="-Wall -std=c99 -Werror -fmax-errors=3 -ggdb -O0 -g3" ` \
-    && BINEXT= \
-    && CC=x86_64-w64-mingw32-gcc \
-    && (mkdir build build/bin || true) \
-    && ${CC:?} -o build/bin/pem-codec${BINEXT} ${CFLAGS} src/main/c/foo/PemCodec.c \
-    && true
-
-*/
 
 /* System */
 #include <assert.h>
@@ -41,8 +27,8 @@ enum Mode {
 struct PemCodec {
     int isHelp; /* TODO flg */
     enum Mode mode; /* one of "ENCODE" or "DECODE" */
-    unsigned char buf[BUF_CAP];
     int buf_len;
+    unsigned char buf[BUF_CAP];
 };
 
 
@@ -80,46 +66,15 @@ static int parseArgs( int argc, char**argv, PemCodec*app ){
 }
 
 
-static int decode( PemCodec*app ){
+static int decodeB64UpToDash( PemCodec*app ){
     int err;
     size_t sz;
-
-    sz = fread(app->buf, 11, 1, stdin);
-    if( sz != 1 ){
-        assert(!fprintf(stderr, "fread: %s  %s:%d\n", strerror(errno), __FILE__, __LINE__)); return -1;
-    }
-
-    if( memcmp(app->buf, "-----BEGIN ", 11) ){
-        fprintf(stderr, "EINVAL: No valid PEM header found\n");
-        return -EINVAL;
-    }
-
-    /* read until EOL */
-    int numDashesInSequence = 0;
-    for(;;){
-        sz = fread(app->buf, 1, 1, stdin);
-        if( sz != 1 ){
-            assert(!fprintf(stderr, "TODO %llu  %s:%d\n", sz, __FILE__, __LINE__));
-        }
-        if( app->buf[0] == '\n' ){
-            if( numDashesInSequence != 5 ){
-                fprintf(stderr, "EINVAL: No valid PEM header found\n");
-                return -1;
-            }
-            break;
-        }
-        if( app->buf[0] == '-' ){
-            numDashesInSequence += 1;
-        }else{
-            numDashesInSequence = 0;
-        }
-    }
-
-    /* decode b64 */
     int iByte;
     int sextets[4];
+
 readFourInputOctets:
     iByte = 0;
+
 readNextInputOctet:
     sz = fread(app->buf, 1, 1, stdin);
     if( sz != 1 ){ assert(!"TODO_20230825155237"); }
@@ -141,9 +96,10 @@ readNextInputOctet:
     }else if( app->buf[0] == '\n' ){ /* ignore newlines */
         goto readNextInputOctet;
     }else if( app->buf[0] == '-' ){ /* EndOf b64 data */
-        goto readEndOfPemLine;
+        goto endFn;
     }else{
-        assert(!"TODO_20230825155655");
+        fprintf(stderr, "Unexpected octet 0x%02X in b64 stream\n", app->buf[0]);
+        err = -1; goto endFn;
     }
 
     if( ++iByte < 4 ) goto readNextInputOctet; /* aka loop */
@@ -157,13 +113,63 @@ readNextInputOctet:
     if( err < 0 ){
         err = errno;
         fprintf(stderr, "printf: %s\n", strerror(errno));
-        return -errno;
+        err = -errno; goto endFn;
     }
 
     goto readFourInputOctets; /* aka loop */
 
-readEndOfPemLine:
-    /* 1st dash got already consumed above */
+    err = 0;
+endFn:
+    return err;
+}
+
+
+static int decodePem( PemCodec*app ){
+    int err;
+    size_t sz;
+
+    sz = fread(app->buf, 11, 1, stdin);
+    if( sz != 1 ){
+        const char *fmt = feof(stdin)
+            ? "Unexpected EOF while reading PEM header: %s\n"
+            : "Cannot read PEM header: %s\n";
+        fprintf(stderr, fmt, strerror(errno));
+        err = -1; goto endFn;
+    }
+
+    if( memcmp(app->buf, "-----BEGIN ", 11) ){
+        fprintf(stderr, "EINVAL: No valid PEM header found\n");
+        err = -1; goto endFn;
+    }
+
+    /* read until EOL */
+    int numDashesInSequence = 0;
+    for(;;){
+        sz = fread(app->buf, 1, 1, stdin);
+        if( sz != 1 ){
+            const char *fmt = feof(stdin)
+                ? "Unexpected EOF while reading PEM header: %s\n"
+                : "Cannot read PEM header: %s\n";
+            fprintf(stderr, fmt, strerror(errno));
+            err = -1; goto endFn;
+        }
+        if( app->buf[0] == '\n' ){
+            if( numDashesInSequence != 5 ){
+                fprintf(stderr, "EINVAL: No valid PEM header found\n");
+                err = -1; goto endFn;
+            }
+            break;
+        }
+        if( app->buf[0] == '-' ){
+            numDashesInSequence += 1;
+        }else{
+            numDashesInSequence = 0;
+        }
+    }
+
+    if( (err=decodeB64UpToDash(app)) < 0 ){ goto endFn; }
+
+    /* readEndOfPemLine. 1st dash got already consumed in func above */
     sz = fread(app->buf, 8, 1, stdin);
     if( sz != 1 || memcmp(app->buf, "----END ", 8)){
         assert(fprintf(stderr, "sz=%llu\n", sz));
@@ -180,33 +186,35 @@ drain:
     if( sz > 0 ) goto drain;
     if( ferror(stdin) ){
         fprintf(stderr, "fread: %s\n", strerror(errno));
-        return -1;
+        err = -1; goto endFn;
     }
 
-    return 0;
+    err = 0;
+endFn:
+    return err;
 }
 
 
 int main( int argc, char**argv ){
-    int ax;
+    int err;
     PemCodec app;
     #define app (&app)
 
-    if( (ax=parseArgs(argc, argv, app)) != 0 ){ goto endFn; }
+    if( (err=parseArgs(argc, argv, app)) != 0 ){ goto endFn; }
 
-    if( app->isHelp ){ printHelp(app); ax = 0; goto endFn; }
+    if( app->isHelp ){ printHelp(app); err = 0; goto endFn; }
 
     if( app->mode == MODE_ENCODE ){
         fprintf(stderr, "ENOTSUP: PEM Encode not implented yet\n");
-        ax = -1; goto endFn;
+        err = -1; goto endFn;
     }else{
         assert(app->mode == MODE_DECODE);
-        ax = decode(app);
+        err = decodePem(app);
         goto endFn;
     }
 
 endFn:
-    return !!ax;
+    return !!err;
     #undef app
 }