diff --git a/library/x509.c b/library/x509.c
index 8a44264..6e16c4c 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -1438,7 +1438,22 @@
                    san_buf, sizeof(*san_buf));
         }
         break;
-
+        /*
+         * IP address
+         */
+        case (MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_X509_SAN_IP_ADDRESS):
+        {
+            memset(san, 0, sizeof(mbedtls_x509_subject_alternative_name));
+            san->type = MBEDTLS_X509_SAN_IP_ADDRESS;
+            // Only IPv6 (16 bytes) and IPv4 (4 bytes) types are supported
+            if (san_buf->len == 4 || san_buf->len == 16) {
+                memcpy(&san->san.unstructured_name,
+                       san_buf, sizeof(*san_buf));
+            } else {
+                return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
+            }
+        }
+        break;
         /*
          * rfc822Name
          */
@@ -1449,7 +1464,6 @@
             memcpy(&san->san.unstructured_name, san_buf, sizeof(*san_buf));
         }
         break;
-
         /*
          * directoryName
          */
@@ -1564,7 +1578,9 @@
                 ret = mbedtls_snprintf(p, n, "\n%s    uniformResourceIdentifier : ", prefix);
                 MBEDTLS_X509_SAFE_SNPRINTF;
                 if (san.san.unstructured_name.len >= n) {
-                    *p = '\0';
+                    if (n > 0) {
+                        *p = '\0';
+                    }
                     return MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
                 }
 
@@ -1590,7 +1606,9 @@
                                        MBEDTLS_X509_SAN_DNS_NAME ? dns_name : rfc822_name);
                 MBEDTLS_X509_SAFE_SNPRINTF;
                 if (san.san.unstructured_name.len >= n) {
-                    *p = '\0';
+                    if (n > 0) {
+                        *p = '\0';
+                    }
                     return MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
                 }
 
@@ -1599,7 +1617,41 @@
                 n -= san.san.unstructured_name.len;
             }
             break;
+            /*
+             * iPAddress
+             */
+            case MBEDTLS_X509_SAN_IP_ADDRESS:
+            {
+                ret = mbedtls_snprintf(p, n, "\n%s    %s : ",
+                                       prefix, "iPAddress");
+                MBEDTLS_X509_SAFE_SNPRINTF;
+                if (san.san.unstructured_name.len >= n) {
+                    if (n > 0) {
+                        *p = '\0';
+                    }
+                    return MBEDTLS_ERR_X509_BUFFER_TOO_SMALL;
+                }
 
+                unsigned char *ip = san.san.unstructured_name.p;
+                // Only IPv6 (16 bytes) and IPv4 (4 bytes) types are supported
+                if (san.san.unstructured_name.len == 4) {
+                    ret = mbedtls_snprintf(p, n, "%u.%u.%u.%u", ip[0], ip[1], ip[2], ip[3]);
+                    MBEDTLS_X509_SAFE_SNPRINTF;
+                } else if (san.san.unstructured_name.len == 16) {
+                    ret = mbedtls_snprintf(p, n,
+                                           "%X%X:%X%X:%X%X:%X%X:%X%X:%X%X:%X%X:%X%X",
+                                           ip[0], ip[1], ip[2], ip[3], ip[4], ip[5], ip[6],
+                                           ip[7], ip[8], ip[9], ip[10], ip[11], ip[12], ip[13],
+                                           ip[14], ip[15]);
+                    MBEDTLS_X509_SAFE_SNPRINTF;
+                } else {
+                    if (n > 0) {
+                        *p = '\0';
+                    }
+                    return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
+                }
+            }
+            break;
             /*
              * directoryName
              */
@@ -1615,6 +1667,9 @@
 
                 if (ret < 0) {
                     mbedtls_x509_free_subject_alt_name(&san);
+                    if (n > 0) {
+                        *p = '\0';
+                    }
                     return ret;
                 }
 
diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index ea8e0c9..b6f347e 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -440,8 +440,12 @@
 server5-fan.crt: server5.key
 	$(OPENSSL) req -x509 -new -subj "/C=UK/O=Mbed TLS/CN=Mbed TLS FAN" -set_serial 77 -config $(test_ca_config_file) -extensions fan_cert -days 3650 -sha256 -key server5.key -out $@
 
-server5-tricky-ip-san.crt: server5.key
-	$(OPENSSL) req -x509 -new -subj "/C=UK/O=Mbed TLS/CN=Mbed TLS Tricky IP SAN" -set_serial 77 -config $(test_ca_config_file) -extensions tricky_ip_san -days 3650 -sha256 -key server5.key -out $@
+server5-tricky-ip-san.crt.der: server5.key
+	$(OPENSSL) req -x509 -new -subj "/C=UK/O=Mbed TLS/CN=Mbed TLS Tricky IP SAN" -set_serial 77 -config $(test_ca_config_file) -extensions tricky_ip_san -days 3650 -sha256 -key server5.key -outform der -out $@
+
+# malformed IP length
+server5-tricky-ip-san-malformed-len.crt.der: server5-tricky-ip-san.crt.der
+	hexdump -ve '1/1 "%.2X"' $< | sed "s/87046162636487106162/87056162636487106162/" | xxd -r -p > $@
 
 server5-directoryname.crt.der: server5.key
 	$(OPENSSL) req -x509 -outform der -new -subj "/C=UK/O=Mbed TLS/CN=Mbed TLS directoryName SAN" -set_serial 77 -config $(test_ca_config_file) -extensions directory_name_san -days 3650 -sha256 -key server5.key -out $@
diff --git a/tests/data_files/server5-tricky-ip-san-malformed-len.crt.der b/tests/data_files/server5-tricky-ip-san-malformed-len.crt.der
new file mode 100644
index 0000000..a26da6c
--- /dev/null
+++ b/tests/data_files/server5-tricky-ip-san-malformed-len.crt.der
Binary files differ
diff --git a/tests/data_files/server5-tricky-ip-san.crt b/tests/data_files/server5-tricky-ip-san.crt
deleted file mode 100644
index 135830f..0000000
--- a/tests/data_files/server5-tricky-ip-san.crt
+++ /dev/null
@@ -1,11 +0,0 @@
------BEGIN CERTIFICATE-----
-MIIBljCCATygAwIBAgIBTTAKBggqhkjOPQQDAjBBMQswCQYDVQQGEwJVSzERMA8G
-A1UECgwITWJlZCBUTFMxHzAdBgNVBAMMFk1iZWQgVExTIFRyaWNreSBJUCBTQU4w
-HhcNMjAwNzIzMTAyNzQ2WhcNMzAwNzIxMTAyNzQ2WjBBMQswCQYDVQQGEwJVSzER
-MA8GA1UECgwITWJlZCBUTFMxHzAdBgNVBAMMFk1iZWQgVExTIFRyaWNreSBJUCBT
-QU4wWTATBgcqhkjOPQIBBggqhkjOPQMBBwNCAAQ3zFbZdgkeWnI+x1kt/yBu7nz5
-BpF00K0UtfdoIllikk7lANgjEf/qL9I0XV0WvYqIwmt3DVXNiioO+gHItO3/oyUw
-IzAhBgNVHREEGjAYhwRhYmNkhxBhYmNkLmV4YW1wbGUuY29tMAoGCCqGSM49BAMC
-A0gAMEUCIFDc8ZALA/9Zv7dZTWrZOOp/dgPAEJRT+h68nD6KF+XyAiEAs1QqugOo
-Dwru0DSEmpYkmj1Keunpd0VopM0joC1cc5A=
------END CERTIFICATE-----
diff --git a/tests/data_files/server5-tricky-ip-san.crt.der b/tests/data_files/server5-tricky-ip-san.crt.der
new file mode 100644
index 0000000..0bd06f8
--- /dev/null
+++ b/tests/data_files/server5-tricky-ip-san.crt.der
Binary files differ
diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index 36f1df1..35ad93e 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -128,7 +128,7 @@
 
 X509 CRT information, Subject Alt Name + Key Usage
 depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_RSA_C:MBEDTLS_MD_CAN_SHA1
-x509_cert_info:"data_files/parse_input/cert_example_multi_nocn.crt":"cert. version     \: 3\nserial number     \: F7\:C6\:7F\:F8\:E9\:A9\:63\:F9\nissuer name       \: C=NL\nsubject name      \: C=NL\nissued  on        \: 2014-01-22 10\:04\:33\nexpires on        \: 2024-01-22 10\:04\:33\nsigned using      \: RSA with SHA1\nRSA key size      \: 1024 bits\nbasic constraints \: CA=false\nsubject alt name  \:\n    dNSName \: www.shotokan-braunschweig.de\n    dNSName \: www.massimo-abate.eu\n    <unsupported>\n    <unsupported>\nkey usage         \: Digital Signature, Non Repudiation, Key Encipherment\n"
+x509_cert_info:"data_files/parse_input/cert_example_multi_nocn.crt":"cert. version     \: 3\nserial number     \: F7\:C6\:7F\:F8\:E9\:A9\:63\:F9\nissuer name       \: C=NL\nsubject name      \: C=NL\nissued  on        \: 2014-01-22 10\:04\:33\nexpires on        \: 2024-01-22 10\:04\:33\nsigned using      \: RSA with SHA1\nRSA key size      \: 1024 bits\nbasic constraints \: CA=false\nsubject alt name  \:\n    dNSName \: www.shotokan-braunschweig.de\n    dNSName \: www.massimo-abate.eu\n    iPAddress \: 192.168.1.1\n    iPAddress \: 192.168.69.144\nkey usage         \: Digital Signature, Non Repudiation, Key Encipherment\n"
 
 X509 CRT information, Subject Alt Name with uniformResourceIdentifier
 depends_on:MBEDTLS_RSA_C:MBEDTLS_MD_CAN_SHA256
@@ -190,6 +190,10 @@
 depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_RSA_C:MBEDTLS_MD_CAN_SHA256
 x509_cert_info:"data_files/parse_input/non-ascii-string-in-issuer.crt":"cert. version     \: 3\nserial number     \: 05\:E6\:53\:E7\:1B\:74\:F0\:B5\:D3\:84\:6D\:0C\:6D\:DC\:FA\:3F\:A4\:5A\:2B\:E0\nissuer name       \: C=JP, ST=Tokyo, O=?????????????????? Ltd, CN=?????????????????? CA\nsubject name      \: C=JP, ST=Tokyo, O=?????????????????? Ltd, CN=?????????????????? CA\nissued  on        \: 2020-05-20 16\:17\:23\nexpires on        \: 2020-06-19 16\:17\:23\nsigned using      \: RSA with SHA-256\nRSA key size      \: 2048 bits\nbasic constraints \: CA=true\n"
 
+X509 CRT information Parsing IPv4 and IPv6 IP names
+depends_on:MBEDTLS_PK_CAN_ECDSA_VERIFY:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
+x509_cert_info:"data_files/server5-tricky-ip-san.crt.der":"cert. version     \: 3\nserial number     \: 4D\nissuer name       \: C=UK, O=Mbed TLS, CN=Mbed TLS Tricky IP SAN\nsubject name      \: C=UK, O=Mbed TLS, CN=Mbed TLS Tricky IP SAN\nissued  on        \: 2023-06-05 11\:30\:36\nexpires on        \: 2033-06-02 11\:30\:36\nsigned using      \: ECDSA with SHA256\nEC key size       \: 256 bits\nsubject alt name  \:\n    iPAddress \: 97.98.99.100\n    iPAddress \: 6162\:6364\:2E65\:7861\:6D70\:6C65\:2E63\:6F6D\n"
+
 X509 SAN parsing otherName
 depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_MD_CAN_SHA256
 x509_parse_san:"data_files/parse_input/server5-othername.crt":"type \: 0\notherName \: hardware module name \: hardware type \: 1.3.6.1.4.1.17.3, hardware serial number \: 313233343536\n":0
@@ -230,6 +234,10 @@
 depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_RSA_C:MBEDTLS_MD_CAN_SHA256
 x509_parse_san:"data_files/parse_input/test_cert_rfc822name.crt.der":"type \: 1\nrfc822Name \: my@other.address\ntype \: 1\nrfc822Name \: second@other.address\n":0
 
+X509 CRT information Parsing IP (invalid data)
+depends_on:MBEDTLS_PK_CAN_ECDSA_VERIFY:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
+x509_parse_san:"data_files/server5-tricky-ip-san-malformed-len.crt.der":"":MBEDTLS_ERR_X509_BAD_INPUT_DATA
+
 X509 CRL information #1
 depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_MD_CAN_SHA1:MBEDTLS_RSA_C:!MBEDTLS_X509_REMOVE_INFO
 mbedtls_x509_crl_info:"data_files/parse_input/crl_expired.pem":"CRL version   \: 1\nissuer name   \: C=NL, O=PolarSSL, CN=PolarSSL Test CA\nthis update   \: 2011-02-20 10\:24\:19\nnext update   \: 2011-02-20 11\:24\:19\nRevoked certificates\:\nserial number\: 01 revocation date\: 2011-02-12 14\:44\:07\nserial number\: 03 revocation date\: 2011-02-12 14\:44\:07\nsigned using  \: RSA with SHA1\n"
@@ -1016,32 +1024,32 @@
 x509_verify:"data_files/server1.crt":"data_files/test-ca.crt":"data_files/crl-futureRevocationDate.pem":"NULL":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_REVOKED:"compat":"NULL"
 
 X509 CRT verification: domain identical to IPv4 in SubjectAltName
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_PK_CAN_ECDSA_VERIFY:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
-x509_verify:"data_files/server5-tricky-ip-san.crt":"data_files/server5-tricky-ip-san.crt":"data_files/crl_sha256.pem":"abcd":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_CN_MISMATCH:"":"NULL"
+depends_on:MBEDTLS_PK_CAN_ECDSA_VERIFY:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
+x509_verify:"data_files/server5-tricky-ip-san.crt.der":"data_files/server5-tricky-ip-san.crt.der":"data_files/crl_sha256.pem":"abcd":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_CN_MISMATCH:"":"NULL"
 
 X509 CRT verification: domain identical to IPv6 in SubjectAltName
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_PK_CAN_ECDSA_VERIFY:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
-x509_verify:"data_files/server5-tricky-ip-san.crt":"data_files/server5-tricky-ip-san.crt":"data_files/crl_sha256.pem":"abcd.example.com":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_CN_MISMATCH:"":"NULL"
+depends_on:MBEDTLS_PK_CAN_ECDSA_VERIFY:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
+x509_verify:"data_files/server5-tricky-ip-san.crt.der":"data_files/server5-tricky-ip-san.crt.der":"data_files/crl_sha256.pem":"abcd.example.com":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_CN_MISMATCH:"":"NULL"
 
 X509 CRT verification: matching IPv4 in SubjectAltName
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
-x509_verify:"data_files/server5-tricky-ip-san.crt":"data_files/server5-tricky-ip-san.crt":"data_files/crl_sha256.pem":"97.98.99.100":0:0:"":"NULL"
+depends_on:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
+x509_verify:"data_files/server5-tricky-ip-san.crt.der":"data_files/server5-tricky-ip-san.crt.der":"data_files/crl_sha256.pem":"97.98.99.100":0:0:"":"NULL"
 
 X509 CRT verification: mismatching IPv4 in SubjectAltName
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
-x509_verify:"data_files/server5-tricky-ip-san.crt":"data_files/server5-tricky-ip-san.crt":"data_files/crl_sha256.pem":"7.8.9.10":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_CN_MISMATCH:"":"NULL"
+depends_on:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
+x509_verify:"data_files/server5-tricky-ip-san.crt.der":"data_files/server5-tricky-ip-san.crt.der":"data_files/crl_sha256.pem":"7.8.9.10":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_CN_MISMATCH:"":"NULL"
 
 X509 CRT verification: IPv4 with trailing data in SubjectAltName
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
-x509_verify:"data_files/server5-tricky-ip-san.crt":"data_files/server5-tricky-ip-san.crt":"data_files/crl_sha256.pem":"97.98.99.100?":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_CN_MISMATCH:"":"NULL"
+depends_on:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
+x509_verify:"data_files/server5-tricky-ip-san.crt.der":"data_files/server5-tricky-ip-san.crt.der":"data_files/crl_sha256.pem":"97.98.99.100?":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_CN_MISMATCH:"":"NULL"
 
 X509 CRT verification: matching IPv6 in SubjectAltName
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
-x509_verify:"data_files/server5-tricky-ip-san.crt":"data_files/server5-tricky-ip-san.crt":"data_files/crl_sha256.pem":"6162\:6364\:2E65\:7861\:6D70\:6C65\:2E63\:6F6D":0:0:"":"NULL"
+depends_on:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
+x509_verify:"data_files/server5-tricky-ip-san.crt.der":"data_files/server5-tricky-ip-san.crt.der":"data_files/crl_sha256.pem":"6162\:6364\:2E65\:7861\:6D70\:6C65\:2E63\:6F6D":0:0:"":"NULL"
 
 X509 CRT verification: mismatching IPv6 in SubjectAltName
-depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
-x509_verify:"data_files/server5-tricky-ip-san.crt":"data_files/server5-tricky-ip-san.crt":"data_files/crl_sha256.pem":"6162\:6364\:\:6F6D":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_CN_MISMATCH:"":"NULL"
+depends_on:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C
+x509_verify:"data_files/server5-tricky-ip-san.crt.der":"data_files/server5-tricky-ip-san.crt.der":"data_files/crl_sha256.pem":"6162\:6364\:\:6F6D":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCERT_CN_MISMATCH:"":"NULL"
 
 X509 CRT verification: matching URI in SubjectAltName
 depends_on:MBEDTLS_PEM_PARSE_C:MBEDTLS_PK_CAN_ECDSA_SOME:MBEDTLS_MD_CAN_SHA256:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_RSA_C