diff --git a/Makefile b/Makefile
index d74e8bc..3cdcd7a 100644
--- a/Makefile
+++ b/Makefile
@@ -22,6 +22,7 @@ clean:
 	$(MAKE) -C asn1-compiled lib-clean
 	$(MAKE) -C src clean
 	$(MAKE) -C tests clean
+	rm -rf project.tgz cov-int
 
 install: all
 	mkdir -p $(DESTDIR)/$(HDR)
@@ -31,4 +32,14 @@ install: all
 	cp src/$(LIBSOVER) $(DESTDIR)/$(LIBDIR)/$(LIBSOVER)
 	ln -s $(LIBSOVER) $(DESTDIR)/$(LIBDIR)/$(LIBSO)
 
-.PHONY: all regenerate-asn1 clean install
+coverity:
+	cov-build --dir cov-int $(MAKE)
+	tar -czf project.tgz cov-int
+	curl --form token=$(COVERITY_LIBTCAP_TOKEN) \
+		--form email=$(DEBEMAIL) \
+		--form file=@project.tgz \
+		--form version="$(LIBTCAP_VERSION)" \
+		--form description="automatic upload" \
+		https://scan.coverity.com/builds?project=$(COVERITY_LIBTCAP_PROJECT)
+
+.PHONY: all regenerate-asn1 clean install coverity
diff --git a/asn1-compiled/INTEGER.c b/asn1-compiled/INTEGER.c
index 56d02b4..0ab29e4 100644
--- a/asn1-compiled/INTEGER.c
+++ b/asn1-compiled/INTEGER.c
@@ -996,6 +996,7 @@ asn_strtol_lim(const char *str, const char **end, long *lp) {
 	case '-':
 		last_digit_max++;
 		sign = -1;
+		/* fall through */
 	case '+':
 		str++;
 		if(str >= *end) {
diff --git a/asn1-compiled/OBJECT_IDENTIFIER.c b/asn1-compiled/OBJECT_IDENTIFIER.c
index 066d562..2eaec9c 100644
--- a/asn1-compiled/OBJECT_IDENTIFIER.c
+++ b/asn1-compiled/OBJECT_IDENTIFIER.c
@@ -296,8 +296,10 @@ OBJECT_IDENTIFIER__xer_body_decode(asn_TYPE_descriptor_t *td, void *sptr, const
 		ret = OBJECT_IDENTIFIER_parse_arcs(
 			(const char *)chunk_buf, chunk_size,
 			arcs, arcs_count, &endptr);
-		if(ret != arcs_count)
+		if(ret != arcs_count) {
+            free(arcs);
 			return XPBD_SYSTEM_FAILURE;	/* assert?.. */
+        }
 	}
 
 	/*
diff --git a/asn1-compiled/OCTET_STRING.c b/asn1-compiled/OCTET_STRING.c
index 584def8..3cb9d81 100644
--- a/asn1-compiled/OCTET_STRING.c
+++ b/asn1-compiled/OCTET_STRING.c
@@ -1594,6 +1594,9 @@ OCTET_STRING_encode_uper(asn_TYPE_descriptor_t *td,
 			_ASN_ENCODE_FAILED;
 	}
 
+    if(!st->buf)
+		_ASN_ENCODE_FAILED;
+
 	/* X.691, #16.5: zero-length encoding */
 	/* X.691, #16.6: short fixed length encoding (up to 2 octets) */
 	/* X.691, #16.7: long fixed length encoding (up to 64K octets) */
@@ -1712,16 +1715,18 @@ OCTET_STRING_print_utf8(asn_TYPE_descriptor_t *td, const void *sptr,
 void
 OCTET_STRING_free(asn_TYPE_descriptor_t *td, void *sptr, int contents_only) {
 	OCTET_STRING_t *st = (OCTET_STRING_t *)sptr;
-	asn_OCTET_STRING_specifics_t *specs = td->specifics
-				? (asn_OCTET_STRING_specifics_t *)td->specifics
-				: &asn_DEF_OCTET_STRING_specs;
-	asn_struct_ctx_t *ctx = (asn_struct_ctx_t *)
-					((char *)st + specs->ctx_offset);
+	asn_OCTET_STRING_specifics_t *specs;
+	asn_struct_ctx_t *ctx;
 	struct _stack *stck;
 
 	if(!td || !st)
 		return;
 
+	specs = td->specifics
+				? (asn_OCTET_STRING_specifics_t *)td->specifics
+				: &asn_DEF_OCTET_STRING_specs;
+	ctx = (asn_struct_ctx_t *) ((char *)st + specs->ctx_offset);
+
 	ASN_DEBUG("Freeing %s as OCTET STRING", td->name);
 
 	if(st->buf) {
diff --git a/asn1-compiled/constr_CHOICE.c b/asn1-compiled/constr_CHOICE.c
index a9eb719..f0b5383 100644
--- a/asn1-compiled/constr_CHOICE.c
+++ b/asn1-compiled/constr_CHOICE.c
@@ -670,7 +670,6 @@ CHOICE_decode_xer(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
 			case -1:
 				ctx->phase = 5;
 				RETURN(RC_FAIL);
-				continue;
 			case 1:
 				ctx->phase = 3;
 				/* Fall through */
@@ -1029,12 +1028,14 @@ CHOICE_print(asn_TYPE_descriptor_t *td, const void *sptr, int ilevel,
 
 void
 CHOICE_free(asn_TYPE_descriptor_t *td, void *ptr, int contents_only) {
-	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	asn_CHOICE_specifics_t *specs;
 	int present;
 
 	if(!td || !ptr)
 		return;
 
+	specs = (asn_CHOICE_specifics_t *)td->specifics;
+
 	ASN_DEBUG("Freeing %s as CHOICE", td->name);
 
 	/*
diff --git a/asn1-compiled/constr_SEQUENCE.c b/asn1-compiled/constr_SEQUENCE.c
index bc7f4ad..f23fb89 100644
--- a/asn1-compiled/constr_SEQUENCE.c
+++ b/asn1-compiled/constr_SEQUENCE.c
@@ -1149,8 +1149,10 @@ SEQUENCE_decode_uper(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
 		if(!epres) _ASN_DECODE_STARVED;
 
 		/* Get the extensions map */
-		if(per_get_many_bits(pd, epres, 0, bmlength))
+		if(per_get_many_bits(pd, epres, 0, bmlength)) {
+            free(epres);
 			_ASN_DECODE_STARVED;
+        }
 
 		memset(&epmd, 0, sizeof(epmd));
 		epmd.buffer = epres;
diff --git a/asn1-compiled/per_encoder.c b/asn1-compiled/per_encoder.c
index e76ef74..d7aae4f 100644
--- a/asn1-compiled/per_encoder.c
+++ b/asn1-compiled/per_encoder.c
@@ -123,7 +123,7 @@ uper_encode_internal(asn_TYPE_descriptor_t *td, asn_per_constraints_t *constrain
 	/*
 	 * Invoke type-specific encoder.
 	 */
-	if(!td || !td->uper_encoder)
+	if(!(td && td->uper_encoder))
 		_ASN_ENCODE_FAILED;	/* PER is not compiled in */
 
 	po.buffer = po.tmpspace;
diff --git a/asn1-compiled/per_opentype.c b/asn1-compiled/per_opentype.c
index 03a31d2..da26841 100644
--- a/asn1-compiled/per_opentype.c
+++ b/asn1-compiled/per_opentype.c
@@ -65,7 +65,8 @@ uper_open_type_get_simple(asn_codec_ctx_t *ctx, asn_TYPE_descriptor_t *td,
 	asn_per_data_t spd;
 	size_t padding;
 
-	_ASN_STACK_OVERFLOW_CHECK(ctx);
+	if(_ASN_STACK_OVERFLOW_CHECK(ctx))
+		_ASN_DECODE_FAILED;
 
 	ASN_DEBUG("Getting open type %s...", td->name);
 
@@ -106,10 +107,10 @@ uper_open_type_get_simple(asn_codec_ctx_t *ctx, asn_TYPE_descriptor_t *td,
 	if(rv.code == RC_OK) {
 		/* Check padding validity */
 		padding = spd.nbits - spd.nboff;
-                if ((padding < 8 ||
+				if ((padding < 8 ||
 		/* X.691#10.1.3 */
 		(spd.nboff == 0 && spd.nbits == 8 && spd.buffer == buf)) &&
-                    per_get_few_bits(&spd, padding) == 0) {
+					per_get_few_bits(&spd, padding) == 0) {
 			/* Everything is cool */
 			FREEMEM(buf);
 			return rv;
@@ -138,7 +139,8 @@ uper_open_type_get_complex(asn_codec_ctx_t *ctx, asn_TYPE_descriptor_t *td,
 	asn_dec_rval_t rv;
 	ssize_t padding;
 
-	_ASN_STACK_OVERFLOW_CHECK(ctx);
+	if(_ASN_STACK_OVERFLOW_CHECK(ctx))
+		_ASN_DECODE_FAILED;
 
 	ASN_DEBUG("Getting open type %s from %s", td->name,
 		per_data_string(pd));
diff --git a/asn1-compiled/per_support.c b/asn1-compiled/per_support.c
index 2481fff..4bd6318 100644
--- a/asn1-compiled/per_support.c
+++ b/asn1-compiled/per_support.c
@@ -12,7 +12,7 @@ per_data_string(asn_per_data_t *pd) {
 	static char buf[2][32];
 	static int n;
 	n = (n+1) % 2;
-	snprintf(buf[n], sizeof(buf),
+	snprintf(buf[n], sizeof(buf[n]),
 		"{m=%ld span %+ld[%d..%d] (%d)}",
 		(long)pd->moved,
 		(((long)pd->buffer) & 0xf),
@@ -342,8 +342,10 @@ per_put_few_bits(asn_per_outp_t *po, uint32_t bits, int obits) {
 		buf[2] = bits >> 8,
 		buf[3] = bits;
 	else {
-		per_put_few_bits(po, bits >> (obits - 24), 24);
-		per_put_few_bits(po, bits, obits - 24);
+		if (obits >= 24) { /* probably a coverity false positive */
+			per_put_few_bits(po, bits >> (obits - 24), 24);
+			per_put_few_bits(po, bits, obits - 24);
+		}
 	}
 
 	ASN_DEBUG("[PER out %u/%x => %02x buf+%ld]",
diff --git a/asn1/postbuild-coverity.patch b/asn1/postbuild-coverity.patch
new file mode 100644
index 0000000..25f47eb
--- /dev/null
+++ b/asn1/postbuild-coverity.patch
@@ -0,0 +1,186 @@
+diff --git a/asn1-compiled/INTEGER.c b/asn1-compiled/INTEGER.c
+index 56d02b4..0ab29e4 100644
+--- a/asn1-compiled/INTEGER.c
++++ b/asn1-compiled/INTEGER.c
+@@ -996,6 +996,7 @@ asn_strtol_lim(const char *str, const char **end, long *lp) {
+ 	case '-':
+ 		last_digit_max++;
+ 		sign = -1;
++		/* fall through */
+ 	case '+':
+ 		str++;
+ 		if(str >= *end) {
+diff --git a/asn1-compiled/OBJECT_IDENTIFIER.c b/asn1-compiled/OBJECT_IDENTIFIER.c
+index 066d562..2eaec9c 100644
+--- a/asn1-compiled/OBJECT_IDENTIFIER.c
++++ b/asn1-compiled/OBJECT_IDENTIFIER.c
+@@ -296,8 +296,10 @@ OBJECT_IDENTIFIER__xer_body_decode(asn_TYPE_descriptor_t *td, void *sptr, const
+ 		ret = OBJECT_IDENTIFIER_parse_arcs(
+ 			(const char *)chunk_buf, chunk_size,
+ 			arcs, arcs_count, &endptr);
+-		if(ret != arcs_count)
++		if(ret != arcs_count) {
++            free(arcs);
+ 			return XPBD_SYSTEM_FAILURE;	/* assert?.. */
++        }
+ 	}
+ 
+ 	/*
+diff --git a/asn1-compiled/OCTET_STRING.c b/asn1-compiled/OCTET_STRING.c
+index 584def8..3cb9d81 100644
+--- a/asn1-compiled/OCTET_STRING.c
++++ b/asn1-compiled/OCTET_STRING.c
+@@ -1594,6 +1594,9 @@ OCTET_STRING_encode_uper(asn_TYPE_descriptor_t *td,
+ 			_ASN_ENCODE_FAILED;
+ 	}
+ 
++    if(!st->buf)
++		_ASN_ENCODE_FAILED;
++
+ 	/* X.691, #16.5: zero-length encoding */
+ 	/* X.691, #16.6: short fixed length encoding (up to 2 octets) */
+ 	/* X.691, #16.7: long fixed length encoding (up to 64K octets) */
+@@ -1712,16 +1715,18 @@ OCTET_STRING_print_utf8(asn_TYPE_descriptor_t *td, const void *sptr,
+ void
+ OCTET_STRING_free(asn_TYPE_descriptor_t *td, void *sptr, int contents_only) {
+ 	OCTET_STRING_t *st = (OCTET_STRING_t *)sptr;
+-	asn_OCTET_STRING_specifics_t *specs = td->specifics
+-				? (asn_OCTET_STRING_specifics_t *)td->specifics
+-				: &asn_DEF_OCTET_STRING_specs;
+-	asn_struct_ctx_t *ctx = (asn_struct_ctx_t *)
+-					((char *)st + specs->ctx_offset);
++	asn_OCTET_STRING_specifics_t *specs;
++	asn_struct_ctx_t *ctx;
+ 	struct _stack *stck;
+ 
+ 	if(!td || !st)
+ 		return;
+ 
++	specs = td->specifics
++				? (asn_OCTET_STRING_specifics_t *)td->specifics
++				: &asn_DEF_OCTET_STRING_specs;
++	ctx = (asn_struct_ctx_t *) ((char *)st + specs->ctx_offset);
++
+ 	ASN_DEBUG("Freeing %s as OCTET STRING", td->name);
+ 
+ 	if(st->buf) {
+diff --git a/asn1-compiled/constr_CHOICE.c b/asn1-compiled/constr_CHOICE.c
+index a9eb719..f0b5383 100644
+--- a/asn1-compiled/constr_CHOICE.c
++++ b/asn1-compiled/constr_CHOICE.c
+@@ -670,7 +670,6 @@ CHOICE_decode_xer(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
+ 			case -1:
+ 				ctx->phase = 5;
+ 				RETURN(RC_FAIL);
+-				continue;
+ 			case 1:
+ 				ctx->phase = 3;
+ 				/* Fall through */
+@@ -1029,12 +1028,14 @@ CHOICE_print(asn_TYPE_descriptor_t *td, const void *sptr, int ilevel,
+ 
+ void
+ CHOICE_free(asn_TYPE_descriptor_t *td, void *ptr, int contents_only) {
+-	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
++	asn_CHOICE_specifics_t *specs;
+ 	int present;
+ 
+ 	if(!td || !ptr)
+ 		return;
+ 
++	specs = (asn_CHOICE_specifics_t *)td->specifics;
++
+ 	ASN_DEBUG("Freeing %s as CHOICE", td->name);
+ 
+ 	/*
+diff --git a/asn1-compiled/constr_SEQUENCE.c b/asn1-compiled/constr_SEQUENCE.c
+index bc7f4ad..f23fb89 100644
+--- a/asn1-compiled/constr_SEQUENCE.c
++++ b/asn1-compiled/constr_SEQUENCE.c
+@@ -1149,8 +1149,10 @@ SEQUENCE_decode_uper(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
+ 		if(!epres) _ASN_DECODE_STARVED;
+ 
+ 		/* Get the extensions map */
+-		if(per_get_many_bits(pd, epres, 0, bmlength))
++		if(per_get_many_bits(pd, epres, 0, bmlength)) {
++            free(epres);
+ 			_ASN_DECODE_STARVED;
++        }
+ 
+ 		memset(&epmd, 0, sizeof(epmd));
+ 		epmd.buffer = epres;
+diff --git a/asn1-compiled/per_encoder.c b/asn1-compiled/per_encoder.c
+index e76ef74..d7aae4f 100644
+--- a/asn1-compiled/per_encoder.c
++++ b/asn1-compiled/per_encoder.c
+@@ -123,7 +123,7 @@ uper_encode_internal(asn_TYPE_descriptor_t *td, asn_per_constraints_t *constrain
+ 	/*
+ 	 * Invoke type-specific encoder.
+ 	 */
+-	if(!td || !td->uper_encoder)
++	if(!(td && td->uper_encoder))
+ 		_ASN_ENCODE_FAILED;	/* PER is not compiled in */
+ 
+ 	po.buffer = po.tmpspace;
+diff --git a/asn1-compiled/per_opentype.c b/asn1-compiled/per_opentype.c
+index 03a31d2..da26841 100644
+--- a/asn1-compiled/per_opentype.c
++++ b/asn1-compiled/per_opentype.c
+@@ -65,7 +65,8 @@ uper_open_type_get_simple(asn_codec_ctx_t *ctx, asn_TYPE_descriptor_t *td,
+ 	asn_per_data_t spd;
+ 	size_t padding;
+ 
+-	_ASN_STACK_OVERFLOW_CHECK(ctx);
++	if(_ASN_STACK_OVERFLOW_CHECK(ctx))
++		_ASN_DECODE_FAILED;
+ 
+ 	ASN_DEBUG("Getting open type %s...", td->name);
+ 
+@@ -106,10 +107,10 @@ uper_open_type_get_simple(asn_codec_ctx_t *ctx, asn_TYPE_descriptor_t *td,
+ 	if(rv.code == RC_OK) {
+ 		/* Check padding validity */
+ 		padding = spd.nbits - spd.nboff;
+-                if ((padding < 8 ||
++				if ((padding < 8 ||
+ 		/* X.691#10.1.3 */
+ 		(spd.nboff == 0 && spd.nbits == 8 && spd.buffer == buf)) &&
+-                    per_get_few_bits(&spd, padding) == 0) {
++					per_get_few_bits(&spd, padding) == 0) {
+ 			/* Everything is cool */
+ 			FREEMEM(buf);
+ 			return rv;
+@@ -138,7 +139,8 @@ uper_open_type_get_complex(asn_codec_ctx_t *ctx, asn_TYPE_descriptor_t *td,
+ 	asn_dec_rval_t rv;
+ 	ssize_t padding;
+ 
+-	_ASN_STACK_OVERFLOW_CHECK(ctx);
++	if(_ASN_STACK_OVERFLOW_CHECK(ctx))
++		_ASN_DECODE_FAILED;
+ 
+ 	ASN_DEBUG("Getting open type %s from %s", td->name,
+ 		per_data_string(pd));
+diff --git a/asn1-compiled/per_support.c b/asn1-compiled/per_support.c
+index 2481fff..4bd6318 100644
+--- a/asn1-compiled/per_support.c
++++ b/asn1-compiled/per_support.c
+@@ -12,7 +12,7 @@ per_data_string(asn_per_data_t *pd) {
+ 	static char buf[2][32];
+ 	static int n;
+ 	n = (n+1) % 2;
+-	snprintf(buf[n], sizeof(buf),
++	snprintf(buf[n], sizeof(buf[n]),
+ 		"{m=%ld span %+ld[%d..%d] (%d)}",
+ 		(long)pd->moved,
+ 		(((long)pd->buffer) & 0xf),
+@@ -342,8 +342,10 @@ per_put_few_bits(asn_per_outp_t *po, uint32_t bits, int obits) {
+ 		buf[2] = bits >> 8,
+ 		buf[3] = bits;
+ 	else {
+-		per_put_few_bits(po, bits >> (obits - 24), 24);
+-		per_put_few_bits(po, bits, obits - 24);
++		if (obits >= 24) { /* probably a coverity false positive */
++			per_put_few_bits(po, bits >> (obits - 24), 24);
++			per_put_few_bits(po, bits, obits - 24);
++		}
+ 	}
+ 
+ 	ASN_DEBUG("[PER out %u/%x => %02x buf+%ld]",
diff --git a/src/tcap.c b/src/tcap.c
index 33b9201..5feaa6e 100644
--- a/src/tcap.c
+++ b/src/tcap.c
@@ -111,7 +111,8 @@ void *inap_decode(Invoke_t *invoke, asn_TYPE_descriptor_t **type) {
 		(*type)->free_struct(*type, arg, 0);
 
 nothing:
-	*type = NULL;
+	if(type)
+		*type = NULL;
 	return NULL;
 }
 
@@ -330,7 +331,7 @@ error:
 
 
 static inline char phone_digit(unsigned char d) {
-	if (d >= 0 && d <= 9)
+	if (d <= 9)
 		return '0' + d;
 	switch (d) {
 		case 11:
@@ -345,7 +346,7 @@ static inline char phone_digit(unsigned char d) {
 }
 
 static inline char phone_digit_hex(unsigned char d) {
-	if (d >= 0 && d <= 9)
+	if (d <= 9)
 		return '0' + d;
 	else if (d >= 10 && d <= 15)
 		return 'A' + d - 10;
diff --git a/tests/encode.c b/tests/encode.c
index 6dd5715..76d8359 100644
--- a/tests/encode.c
+++ b/tests/encode.c
@@ -47,7 +47,11 @@ int main() {
 
 	ret = tcap_encode(&buf, &msg);
 	fprintf(stderr, "ret: %i\n", ret);
-	fwrite(buf, ret, 1, stdout);
+    if(ret < 0) {
+	    fprintf(stderr, "failed to encode tcap\n");
+    } else {
+	    fwrite(buf, ret, 1, stdout);
+    }
 
 	free(buf);
 	asn_DEF_ANY.free_struct(&asn_DEF_ANY, cmp.choice.invoke.parameter, 0);