Extracting SubjectKeyId and AuthorityKeyId in case of x509 V3 extensions. Updating mbedtls_x509_crt_free function to also free the new dynamic elements (issuer field of AuthorityKeyId).
A few tests are also added which test the feature with a correct certificate and multiple ones with erroneous ASN1 tags.

Signed-off-by: toth92g <toth92g@gmail.com>
diff --git a/include/mbedtls/x509.h b/include/mbedtls/x509.h
index 8dfd1f3..5a9f2b5 100644
--- a/include/mbedtls/x509.h
+++ b/include/mbedtls/x509.h
@@ -243,6 +243,17 @@
  */
 typedef mbedtls_asn1_sequence mbedtls_x509_sequence;
 
+/*
+ * Container for the fields of the Authority Key Identifier object
+ */
+typedef struct mbedtls_x509_authority {
+    mbedtls_x509_buf keyIdentifier;
+    mbedtls_x509_name authorityCertIssuer;
+    mbedtls_x509_buf authorityCertSerialNumber;
+    mbedtls_x509_buf raw;
+}
+mbedtls_x509_authority;
+
 /** Container for date and time (precision in seconds). */
 typedef struct mbedtls_x509_time {
     int year, mon, day;         /**< Date. */
diff --git a/include/mbedtls/x509_crt.h b/include/mbedtls/x509_crt.h
index 6c86a66..672cdf5 100644
--- a/include/mbedtls/x509_crt.h
+++ b/include/mbedtls/x509_crt.h
@@ -76,6 +76,8 @@
     mbedtls_x509_buf subject_id;        /**< Optional X.509 v2/v3 subject unique identifier. */
     mbedtls_x509_buf v3_ext;            /**< Optional X.509 v3 extensions.  */
     mbedtls_x509_sequence subject_alt_names;    /**< Optional list of raw entries of Subject Alternative Names extension (currently only dNSName, uniformResourceIdentifier, DirectoryName and OtherName are listed). */
+    mbedtls_x509_buf subject_key_id;    /**< Optional X.509 v3 extension subject key identifier. */
+    mbedtls_x509_authority authority_key_id;    /**< Optional X.509 v3 extension authority key identifier. */
 
     mbedtls_x509_sequence certificate_policies; /**< Optional list of certificate policies (Only anyPolicy is printed and enforced, however the rest of the policies are still listed). */
 
diff --git a/library/oid.c b/library/oid.c
index 622e793..79bf554 100644
--- a/library/oid.c
+++ b/library/oid.c
@@ -319,7 +319,17 @@
         MBEDTLS_OID_X509_EXT_CERTIFICATE_POLICIES,
     },
     {
-        NULL_OID_DESCRIPTOR,
+        { ADD_LEN(MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER), "id-ce-subjectKeyIdentifier",
+          "Subject Key Identifier" },
+        MBEDTLS_OID_X509_EXT_SUBJECT_KEY_IDENTIFIER,
+    },
+    {
+        { ADD_LEN(MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER), "id-ce-authorityKeyIdentifier",
+          "Authority Key Identifier" },
+        MBEDTLS_OID_X509_EXT_AUTHORITY_KEY_IDENTIFIER,
+    },
+    {
+        { NULL, 0, NULL, NULL },
         0,
     },
 };
diff --git a/library/x509_crt.c b/library/x509_crt.c
index cf62532..e7a98dd 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -587,6 +587,227 @@
 }
 
 /*
+ * SubjectKeyIdentifier ::= KeyIdentifier
+ *
+ * KeyIdentifier ::= OCTET STRING
+ */
+static int x509_get_subject_key_id(unsigned char **p,
+                                   const unsigned char *end,
+                                   mbedtls_x509_buf *subject_key_id)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t len = 0u;
+
+    if ((ret = mbedtls_asn1_get_tag(p, end, &len,
+                                    MBEDTLS_ASN1_OCTET_STRING)) != 0) {
+        return ret;
+    } else {
+        subject_key_id->len = len;
+        subject_key_id->tag = MBEDTLS_ASN1_OCTET_STRING;
+        subject_key_id->p = *p;
+        *p += len;
+    }
+
+    return 0;
+}
+
+/*
+ * AuthorityKeyIdentifier ::= SEQUENCE {
+ *        keyIdentifier [0] KeyIdentifier OPTIONAL,
+ *        authorityCertIssuer [1] GeneralNames OPTIONAL,
+ *        authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL }
+ *
+ *    KeyIdentifier ::= OCTET STRING
+ */
+static int x509_get_authority_key_id(unsigned char **p,
+                                     unsigned char *end,
+                                     mbedtls_x509_authority *authority_key_id)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t len = 0u;
+
+    if ((ret = mbedtls_asn1_get_tag(p, end, &len,
+                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
+        return ret;
+    }
+
+    if ((ret = mbedtls_asn1_get_tag(p, end, &len,
+                                    MBEDTLS_ASN1_CONTEXT_SPECIFIC)) != 0) {
+        /* KeyIdentifier is an OPTIONAL field */
+    } else {
+        authority_key_id->keyIdentifier.len = len;
+        authority_key_id->keyIdentifier.p = *p;
+        authority_key_id->keyIdentifier.tag = MBEDTLS_ASN1_OCTET_STRING;
+
+        *p += len;
+    }
+
+    if (*p < end) {
+        if ((ret = mbedtls_asn1_get_tag(p, end, &len,
+                                        MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED |
+                                        MBEDTLS_ASN1_BOOLEAN)) != 0) {
+            /* authorityCertIssuer is an OPTIONAL field */
+        } else {
+            if ((ret = mbedtls_asn1_get_tag(p, end, &len,
+                                            MBEDTLS_ASN1_CONTEXT_SPECIFIC |
+                                            MBEDTLS_ASN1_CONSTRUCTED |
+                                            MBEDTLS_ASN1_OCTET_STRING)) != 0) {
+                return ret;
+            } else {
+                authority_key_id->raw.p = *p;
+
+                if ((ret = mbedtls_asn1_get_tag(p, end, &len,
+                                                MBEDTLS_ASN1_CONSTRUCTED |
+                                                MBEDTLS_ASN1_SEQUENCE)) != 0) {
+                    return ret;
+                }
+
+                if ((ret =
+                         mbedtls_x509_get_name(p, *p + len,
+                                               &authority_key_id->authorityCertIssuer)) != 0) {
+                    return ret;
+                }
+
+                authority_key_id->raw.len = *p - authority_key_id->raw.p;
+            }
+        }
+    }
+
+    if (*p < end) {
+        if ((ret = mbedtls_asn1_get_tag(p, end, &len,
+                                        MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_INTEGER)) !=
+            0) {
+            /* authorityCertSerialNumber is an OPTIONAL field, but if there are still data it must be the serial number */
+            return ret;
+        } else {
+            authority_key_id->authorityCertSerialNumber.len = len;
+            authority_key_id->authorityCertSerialNumber.p = *p;
+            authority_key_id->authorityCertSerialNumber.tag = MBEDTLS_ASN1_OCTET_STRING;
+            *p += len;
+        }
+    }
+
+    if (*p != end) {
+        return MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
+               MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
+    }
+
+    return 0;
+}
+
+/*
+ * SubjectAltName ::= GeneralNames
+ *
+ * GeneralNames ::= SEQUENCE SIZE (1..MAX) OF GeneralName
+ *
+ * GeneralName ::= CHOICE {
+ *      otherName                       [0]     OtherName,
+ *      rfc822Name                      [1]     IA5String,
+ *      dNSName                         [2]     IA5String,
+ *      x400Address                     [3]     ORAddress,
+ *      directoryName                   [4]     Name,
+ *      ediPartyName                    [5]     EDIPartyName,
+ *      uniformResourceIdentifier       [6]     IA5String,
+ *      iPAddress                       [7]     OCTET STRING,
+ *      registeredID                    [8]     OBJECT IDENTIFIER }
+ *
+ * OtherName ::= SEQUENCE {
+ *      type-id    OBJECT IDENTIFIER,
+ *      value      [0] EXPLICIT ANY DEFINED BY type-id }
+ *
+ * EDIPartyName ::= SEQUENCE {
+ *      nameAssigner            [0]     DirectoryString OPTIONAL,
+ *      partyName               [1]     DirectoryString }
+ *
+ * NOTE: we list all types, but only use dNSName and otherName
+ * of type HwModuleName, as defined in RFC 4108, at this point.
+ */
+static int x509_get_subject_alt_name(unsigned char **p,
+                                     const unsigned char *end,
+                                     mbedtls_x509_sequence *subject_alt_name)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    size_t len, tag_len;
+    mbedtls_asn1_buf *buf;
+    unsigned char tag;
+    mbedtls_asn1_sequence *cur = subject_alt_name;
+
+    /* Get main sequence tag */
+    if ((ret = mbedtls_asn1_get_tag(p, end, &len,
+                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
+        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
+    }
+
+    if (*p + len != end) {
+        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
+                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
+    }
+
+    while (*p < end) {
+        mbedtls_x509_subject_alternative_name dummy_san_buf;
+        memset(&dummy_san_buf, 0, sizeof(dummy_san_buf));
+
+        tag = **p;
+        (*p)++;
+        if ((ret = mbedtls_asn1_get_len(p, end, &tag_len)) != 0) {
+            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);
+        }
+
+        if ((tag & MBEDTLS_ASN1_TAG_CLASS_MASK) !=
+            MBEDTLS_ASN1_CONTEXT_SPECIFIC) {
+            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
+                                     MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);
+        }
+
+        /*
+         * Check that the SAN is structured correctly.
+         */
+        ret = mbedtls_x509_parse_subject_alt_name(&(cur->buf), &dummy_san_buf);
+        /*
+         * In case the extension is malformed, return an error,
+         * and clear the allocated sequences.
+         */
+        if (ret != 0 && ret != MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE) {
+            mbedtls_asn1_sequence_free(subject_alt_name->next);
+            subject_alt_name->next = NULL;
+            return ret;
+        }
+
+        /* Allocate and assign next pointer */
+        if (cur->buf.p != NULL) {
+            if (cur->next != NULL) {
+                return MBEDTLS_ERR_X509_INVALID_EXTENSIONS;
+            }
+
+            cur->next = mbedtls_calloc(1, sizeof(mbedtls_asn1_sequence));
+
+            if (cur->next == NULL) {
+                return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
+                                         MBEDTLS_ERR_ASN1_ALLOC_FAILED);
+            }
+
+            cur = cur->next;
+        }
+
+        buf = &(cur->buf);
+        buf->tag = tag;
+        buf->p = *p;
+        buf->len = tag_len;
+        *p += buf->len;
+    }
+
+    /* Set final sequence entry's next pointer to NULL */
+    cur->next = NULL;
+
+    if (*p != end) {
+        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,
+                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
+    }
+
+    return 0;
+}
+
+/*
  * id-ce-certificatePolicies OBJECT IDENTIFIER ::=  { id-ce 32 }
  *
  * anyPolicy OBJECT IDENTIFIER ::= { id-ce-certificatePolicies 0 }
@@ -883,7 +1104,20 @@
                     return ret;
                 }
                 break;
-
+            case MBEDTLS_X509_EXT_SUBJECT_KEY_IDENTIFIER:
+                /* Parse subject key identifier */
+                if ((ret = x509_get_subject_key_id(p, end_ext_data,
+                                                   &crt->subject_key_id)) != 0) {
+                    return ret;
+                }
+                break;
+            case MBEDTLS_X509_EXT_AUTHORITY_KEY_IDENTIFIER:
+                /* Parse authority key identifier */
+                if ((ret = x509_get_authority_key_id(p, end_ext_octet,
+                                                     &crt->authority_key_id)) != 0) {
+                    return ret;
+                }
+                break;
             case MBEDTLS_X509_EXT_SUBJECT_ALT_NAME:
                 /* Parse subject alt name */
                 if ((ret = mbedtls_x509_get_subject_alt_name(p, end_ext_octet,
@@ -2838,6 +3072,14 @@
         mbedtls_asn1_sequence_free(cert_cur->subject_alt_names.next);
         mbedtls_asn1_sequence_free(cert_cur->certificate_policies.next);
 
+        name_cur = cert_cur->authority_key_id.authorityCertIssuer.next;
+        while (name_cur != NULL) {
+            name_prv = name_cur;
+            name_cur = name_cur->next;
+            mbedtls_platform_zeroize(name_prv, sizeof(mbedtls_x509_name));
+            mbedtls_free(name_prv);
+        }
+
         if (cert_cur->raw.p != NULL && cert_cur->own_buffer) {
             mbedtls_platform_zeroize(cert_cur->raw.p, cert_cur->raw.len);
             mbedtls_free(cert_cur->raw.p);
diff --git a/tests/data_files/authorityKeyId_subjectKeyId.crt b/tests/data_files/authorityKeyId_subjectKeyId.crt
new file mode 100644
index 0000000..c2c9a63
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId.crt
@@ -0,0 +1,21 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
\ No newline at end of file
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_wrong_AuthorityKeyId_KeyId.crt b/tests/data_files/authorityKeyId_subjectKeyId_wrong_AuthorityKeyId_KeyId.crt
new file mode 100644
index 0000000..bc28741
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_wrong_AuthorityKeyId_KeyId.crt
@@ -0,0 +1,3 @@
+-----BEGIN CERTIFICATE-----
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
+-----END CERTIFICATE-----
\ No newline at end of file
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_wrong_AuthorityKeyId_Sequence.crt b/tests/data_files/authorityKeyId_subjectKeyId_wrong_AuthorityKeyId_Sequence.crt
new file mode 100644
index 0000000..6a7d7f7
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_wrong_AuthorityKeyId_Sequence.crt
@@ -0,0 +1,3 @@
+-----BEGIN CERTIFICATE-----
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
+-----END CERTIFICATE-----
\ No newline at end of file
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer1.crt b/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer1.crt
new file mode 100644
index 0000000..045c570
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer1.crt
@@ -0,0 +1,3 @@
+-----BEGIN CERTIFICATE-----
+MIIDhzCCAm+gAwIBAgIBADANBgkqhkiG9w0BAQUFADA7MQswCQYDVQQGEwJOTDERMA8GA1UEChMIUG9sYXJTU0wxGTAXBgNVBAMTEFBvbGFyU1NMIFRlc3QgQ0EwHhcNMTEwMjEyMTQ0NDAwWhcNMjEwMjEyMTQ0NDAwWjA7MQswCQYDVQQGEwJOTDERMA8GA1UEChMIUG9sYXJTU0wxGTAXBgNVBAMTEFBvbGFyU1NMIFRlc3QgQ0EwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDA3zf8F7vglp0/ht6WMn1EpRagzSHxmdTs6st8GFgIlKXsm8WL3xoemTiZhx57wI053zhdcHgH057Zk+i5clHFzqMwUqny50BwFMtEonILwuVA+T7lpg6z+exKY8C4KQB0nFc7qKUEkHHxvYPZP9al4jwqj+8nYMPGn8u67GB9t+aEMr5P+1gmIgNb1LTV+/Xjli5wwOQuvfwu7uJBVcA0Ln0kcmnLR7EUQIN9Z/SG9jGr8XmksrUuEvmEF/Bibyc+E1ixVA0hmnM3oTDPb5Lc9un8rNsuKNF+AksjoBXyOGVkCeoMbo4bF6BxyLObyavpw/LPh5aPgAIynplYb6LVAgMBAAGjgZUwgZIwDAYDVR0TBAUwAwEB/zAdBgNVHQ4EFgQUtFrkpbPe0lL2udWmlQ/rPrzH/f8wYwYDVR0jBFwwWoAUtFrkpbPe0lL2udWmlQ/rPrzH/f8AP6Q9MDsxCzAJBgNVBAYTAk5MMREwDwYDVQQKEwhQb2xhclNTTDEZMBcGA1UEAxMQUG9sYXJTU0wgVGVzdCBDQYIBADANBgkqhkiG9w0BAQUFAAOCAQEAuP1U2ABUkIslsCfdlc2i94QHHYeJSsR4EdgHtdciUI5I62J6Mom+Y0dT/7a+8S6MVMCZP6C5NyNyXw1GWY/YR82XTJ8HDBJiCTok5DbZ6SzaONBzdWHXwWwmi5vg1dxn7YxrM9d0IjxM27WNKs4sDQhZBQkFpjmfs2cb4oPl4Y9T9meTx/lvdkRYEug61Jfn6cA+qHpyPYdTH+UshITnmp5/Ztkfm/UTSLBNFNHesiTZeH31NcxYGdHSme9Nc/gfidRa0FLOCfWxRlFqAI47zG9jAQCZ7Z2mCGDNMhjQc+BYcdnl0lPXjdDK6V0qCg1dVewhUBcW5gZKzV7e9+DpVA==
+-----END CERTIFICATE-----
\ No newline at end of file
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer2.crt b/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer2.crt
new file mode 100644
index 0000000..a103729
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer2.crt
@@ -0,0 +1,3 @@
+-----BEGIN CERTIFICATE-----
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
+-----END CERTIFICATE-----
\ No newline at end of file
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer3.crt b/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer3.crt
new file mode 100644
index 0000000..dabad62
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer3.crt
@@ -0,0 +1,3 @@
+-----BEGIN CERTIFICATE-----
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
+-----END CERTIFICATE-----
\ No newline at end of file
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer4.crt b/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer4.crt
new file mode 100644
index 0000000..55e6579
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_wrong_Issuer4.crt
@@ -0,0 +1,3 @@
+-----BEGIN CERTIFICATE-----
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
+-----END CERTIFICATE-----
\ No newline at end of file
diff --git a/tests/data_files/authorityKeyId_subjectKeyId_wrong_SubjectKeyId.crt b/tests/data_files/authorityKeyId_subjectKeyId_wrong_SubjectKeyId.crt
new file mode 100644
index 0000000..4c99a2f
--- /dev/null
+++ b/tests/data_files/authorityKeyId_subjectKeyId_wrong_SubjectKeyId.crt
@@ -0,0 +1,3 @@
+-----BEGIN CERTIFICATE-----
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
+-----END CERTIFICATE-----
\ No newline at end of file
diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index 685b859..54bad3c 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -3165,3 +3165,39 @@
 X509 ext types accessor: ext type not present
 depends_on:MBEDTLS_X509_CRT_PARSE_C
 x509_accessor_ext_types:MBEDTLS_X509_EXT_KEY_USAGE:MBEDTLS_X509_EXT_SUBJECT_ALT_NAME
+
+X509 CRT parse Subject Key Id - Correct
+depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C
+mbedtls_x509_crt_parse_subjectkeyid:"data_files/authorityKeyId_subjectKeyId.crt":"B45AE4A5B3DED252F6B9D5A6950FEB3EBCC7FDFF":20:0
+
+X509 CRT parse Subject Key Id - Wrong
+depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C
+mbedtls_x509_crt_parse_subjectkeyid:"data_files/authorityKeyId_subjectKeyId_wrong_SubjectKeyId.crt":"":0:0xff9e
+
+X509 CRT parse Authority Key Id - Correct
+depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C
+mbedtls_x509_crt_parse_authoritykeyid:"data_files/authorityKeyId_subjectKeyId.crt":"B45AE4A5B3DED252F6B9D5A6950FEB3EBCC7FDFF":20:"NL/PolarSSL/PolarSSL Test CA/":"0":1:0
+
+X509 CRT parse Authority Key Id - Wrong Sequence
+depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C
+mbedtls_x509_crt_parse_authoritykeyid:"data_files/authorityKeyId_subjectKeyId_wrong_AuthorityKeyId_Sequence.crt":"":0:"":"0":0:0xff9e
+
+X509 CRT parse Authority Key Id - Wrong KeyId Tag
+depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C
+mbedtls_x509_crt_parse_authoritykeyid:"data_files/authorityKeyId_subjectKeyId_wrong_AuthorityKeyId_KeyId.crt":"":0:"":"0":0:0xff9e
+
+X509 CRT parse Authority Key Id - Wrong Issuer Tag 1
+depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C
+mbedtls_x509_crt_parse_authoritykeyid:"data_files/authorityKeyId_subjectKeyId_wrong_Issuer1.crt":"":0:"":"0":0:0xff9e
+
+X509 CRT parse Authority Key Id - Wrong Issuer Tag 2
+depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C
+mbedtls_x509_crt_parse_authoritykeyid:"data_files/authorityKeyId_subjectKeyId_wrong_Issuer2.crt":"":0:"":"0":0:0xff9e
+
+X509 CRT parse Authority Key Id - Wrong Issuer Tag 3
+depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C
+mbedtls_x509_crt_parse_authoritykeyid:"data_files/authorityKeyId_subjectKeyId_wrong_Issuer3.crt":"":0:"":"0":0:0xff9e
+
+X509 CRT parse Authority Key Id - Wrong Issuer Tag 4
+depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C
+mbedtls_x509_crt_parse_authoritykeyid:"data_files/authorityKeyId_subjectKeyId_wrong_Issuer4.crt":"":0:"":"0":0:0xdc1e
diff --git a/tests/suites/test_suite_x509parse.function b/tests/suites/test_suite_x509parse.function
index 177bc97..12b7818 100644
--- a/tests/suites/test_suite_x509parse.function
+++ b/tests/suites/test_suite_x509parse.function
@@ -1472,3 +1472,95 @@
     ;;
 }
 /* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C */
+void mbedtls_x509_crt_parse_subjectkeyid(char *crt_path,
+                                         char *subjectKeyId,
+                                         int subjectKeyIdLength,
+                                         int retVal)
+{
+    mbedtls_x509_crt crt;
+    int i = 0;
+    int result = 0;
+
+    mbedtls_x509_crt_init(&crt);
+
+    TEST_ASSERT((mbedtls_x509_crt_parse_file(&crt, crt_path)& 0xFFFF) == retVal);
+
+    if (retVal != 0) {
+        while (i < subjectKeyIdLength) {
+            result |= crt.subject_key_id.p[i] != subjectKeyId[i*2];
+            result |= crt.subject_key_id.p[i+1] != subjectKeyId[i*2+1];
+            i++;
+        }
+
+        TEST_ASSERT(result == 0);
+    }
+
+exit:
+    mbedtls_x509_crt_free(&crt);
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_FS_IO:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_CERTS_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C */
+void mbedtls_x509_crt_parse_authoritykeyid(char *crt_path,
+                                           char *authorityKeyId_keyId,
+                                           int keyIdLength,
+                                           char *authorityKeyId_issuer,
+                                           char *authorityKeyId_serial,
+                                           int serialLength,
+                                           int retVal)
+{
+    mbedtls_x509_crt crt;
+    int i = 0;
+    int result = 0;
+    int bufferCounter = 0;
+    size_t issuerCounter = 0;
+
+    mbedtls_x509_crt_init(&crt);
+
+    TEST_ASSERT((mbedtls_x509_crt_parse_file(&crt, crt_path)& 0xFFFF) == retVal);
+
+    if (retVal != 0) {
+        /* KeyId test */
+        while (i < keyIdLength) {
+            result |= crt.authority_key_id.keyIdentifier.p[i] != authorityKeyId_keyId[i*2];
+            result |= crt.authority_key_id.keyIdentifier.p[i+1] != authorityKeyId_keyId[i*2+1];
+            i++;
+        }
+
+        /* Issuer test */
+        mbedtls_x509_name *issuerPtr = &crt.authority_key_id.authorityCertIssuer;
+        while (issuerPtr != NULL) {
+            for (issuerCounter = 0u; issuerCounter < issuerPtr->val.len; issuerCounter++) {
+                result |=
+                    (authorityKeyId_issuer[bufferCounter++] != issuerPtr->val.p[issuerCounter]);
+            }
+            bufferCounter++; /* Skipping the slash */
+            issuerPtr = issuerPtr->next;
+        }
+
+        /* Serial test */
+        i = 0;
+        while (i < serialLength) {
+            result |= crt.authority_key_id.authorityCertSerialNumber.p[i] !=
+                      authorityKeyId_serial[i*2];
+            result |= crt.authority_key_id.authorityCertSerialNumber.p[i+1] !=
+                      authorityKeyId_serial[i*2+1];
+            i++;
+        }
+
+        TEST_ASSERT(result == 0);
+    }
+
+exit:
+    mbedtls_x509_crt_free(&crt);
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_X509_CRT_PARSE_C:MBEDTLS_SELF_TEST */
+void x509_selftest()
+{
+    TEST_ASSERT(mbedtls_x509_self_test(1) == 0);
+}
+/* END_CASE */