diff --git a/drivers/auth/dualroot/cot.c b/drivers/auth/dualroot/cot.c
new file mode 100644
index 0000000..eb0b020
--- /dev/null
+++ b/drivers/auth/dualroot/cot.c
@@ -0,0 +1,814 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stddef.h>
+
+#include <platform_def.h>
+
+#include <drivers/auth/mbedtls/mbedtls_config.h>
+#include <drivers/auth/auth_mod.h>
+#include <tools_share/dualroot_oid.h>
+
+/*
+ * TODO: Remove dependency on mbedTLS. The chain of trust should be agnostic of
+ * the specific cryptographic library in use.
+*/
+/*
+ * Maximum key and hash sizes (in DER format).
+ *
+ * Both RSA and ECDSA keys may be used at the same time. In this case, the key
+ * buffers must be big enough to hold either. As RSA keys are bigger than ECDSA
+ * ones for all key sizes we support, they impose the minimum size of these
+ * buffers.
+ */
+#if TF_MBEDTLS_USE_RSA
+#if TF_MBEDTLS_KEY_SIZE == 1024
+#define PK_DER_LEN			162
+#elif TF_MBEDTLS_KEY_SIZE == 2048
+#define PK_DER_LEN			294
+#elif TF_MBEDTLS_KEY_SIZE == 3072
+#define PK_DER_LEN			422
+#elif TF_MBEDTLS_KEY_SIZE == 4096
+#define PK_DER_LEN			550
+#else
+#error "Invalid value for TF_MBEDTLS_KEY_SIZE"
+#endif
+#else /* Only using ECDSA keys. */
+#define PK_DER_LEN			91
+#endif
+
+#if TF_MBEDTLS_HASH_ALG_ID == TF_MBEDTLS_SHA256
+#define HASH_DER_LEN			51
+#elif TF_MBEDTLS_HASH_ALG_ID == TF_MBEDTLS_SHA384
+#define HASH_DER_LEN			67
+#elif TF_MBEDTLS_HASH_ALG_ID == TF_MBEDTLS_SHA512
+#define HASH_DER_LEN			83
+#else
+#error "Invalid value for TF_MBEDTLS_HASH_ALG_ID"
+#endif
+
+/*
+ * Allocate static buffers to store the authentication parameters extracted from
+ * the certificates.
+ */
+static unsigned char tb_fw_hash_buf[HASH_DER_LEN];
+static unsigned char tb_fw_config_hash_buf[HASH_DER_LEN];
+static unsigned char hw_config_hash_buf[HASH_DER_LEN];
+static unsigned char scp_fw_hash_buf[HASH_DER_LEN];
+static unsigned char nt_world_bl_hash_buf[HASH_DER_LEN];
+
+#ifdef IMAGE_BL2
+static unsigned char soc_fw_hash_buf[HASH_DER_LEN];
+static unsigned char tos_fw_hash_buf[HASH_DER_LEN];
+static unsigned char tos_fw_extra1_hash_buf[HASH_DER_LEN];
+static unsigned char tos_fw_extra2_hash_buf[HASH_DER_LEN];
+static unsigned char soc_fw_config_hash_buf[HASH_DER_LEN];
+static unsigned char tos_fw_config_hash_buf[HASH_DER_LEN];
+static unsigned char nt_fw_config_hash_buf[HASH_DER_LEN];
+
+static unsigned char trusted_world_pk_buf[PK_DER_LEN];
+static unsigned char content_pk_buf[PK_DER_LEN];
+#endif
+
+/*
+ * Parameter type descriptors.
+ */
+static auth_param_type_desc_t trusted_nv_ctr = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_NV_CTR, TRUSTED_FW_NVCOUNTER_OID);
+static auth_param_type_desc_t subject_pk = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_PUB_KEY, 0);
+static auth_param_type_desc_t sig = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_SIG, 0);
+static auth_param_type_desc_t sig_alg = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_SIG_ALG, 0);
+static auth_param_type_desc_t raw_data = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_RAW_DATA, 0);
+
+static auth_param_type_desc_t tb_fw_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, TRUSTED_BOOT_FW_HASH_OID);
+static auth_param_type_desc_t tb_fw_config_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, TRUSTED_BOOT_FW_CONFIG_HASH_OID);
+static auth_param_type_desc_t hw_config_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, HW_CONFIG_HASH_OID);
+#ifdef IMAGE_BL1
+static auth_param_type_desc_t scp_bl2u_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, SCP_FWU_CFG_HASH_OID);
+static auth_param_type_desc_t bl2u_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, AP_FWU_CFG_HASH_OID);
+static auth_param_type_desc_t ns_bl2u_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, FWU_HASH_OID);
+#endif /* IMAGE_BL1 */
+
+#ifdef IMAGE_BL2
+static auth_param_type_desc_t non_trusted_nv_ctr = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_NV_CTR, NON_TRUSTED_FW_NVCOUNTER_OID);
+
+static auth_param_type_desc_t trusted_world_pk = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_PUB_KEY, TRUSTED_WORLD_PK_OID);
+static auth_param_type_desc_t scp_fw_content_pk = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_PUB_KEY, SCP_FW_CONTENT_CERT_PK_OID);
+static auth_param_type_desc_t soc_fw_content_pk = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_PUB_KEY, SOC_FW_CONTENT_CERT_PK_OID);
+static auth_param_type_desc_t tos_fw_content_pk = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_PUB_KEY, TRUSTED_OS_FW_CONTENT_CERT_PK_OID);
+static auth_param_type_desc_t prot_pk = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_PUB_KEY, PROT_PK_OID);
+
+static auth_param_type_desc_t scp_fw_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, SCP_FW_HASH_OID);
+static auth_param_type_desc_t soc_fw_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, SOC_AP_FW_HASH_OID);
+static auth_param_type_desc_t soc_fw_config_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, SOC_FW_CONFIG_HASH_OID);
+static auth_param_type_desc_t tos_fw_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, TRUSTED_OS_FW_HASH_OID);
+static auth_param_type_desc_t tos_fw_config_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, TRUSTED_OS_FW_CONFIG_HASH_OID);
+static auth_param_type_desc_t tos_fw_extra1_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, TRUSTED_OS_FW_EXTRA1_HASH_OID);
+static auth_param_type_desc_t tos_fw_extra2_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, TRUSTED_OS_FW_EXTRA2_HASH_OID);
+static auth_param_type_desc_t nt_world_bl_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, NON_TRUSTED_WORLD_BOOTLOADER_HASH_OID);
+static auth_param_type_desc_t nt_fw_config_hash = AUTH_PARAM_TYPE_DESC(
+		AUTH_PARAM_HASH, NON_TRUSTED_FW_CONFIG_HASH_OID);
+#endif /* IMAGE_BL2 */
+
+
+/* BL2 */
+static const auth_img_desc_t trusted_boot_fw_cert = {
+	.img_id = TRUSTED_BOOT_FW_CERT_ID,
+	.img_type = IMG_CERT,
+	.parent = NULL,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_SIG,
+			.param.sig = {
+				.pk = &subject_pk,
+				.sig = &sig,
+				.alg = &sig_alg,
+				.data = &raw_data
+			}
+		},
+		[1] = {
+			.type = AUTH_METHOD_NV_CTR,
+			.param.nv_ctr = {
+				.cert_nv_ctr = &trusted_nv_ctr,
+				.plat_nv_ctr = &trusted_nv_ctr
+			}
+		}
+	},
+	.authenticated_data = (const auth_param_desc_t[COT_MAX_VERIFIED_PARAMS]) {
+		[0] = {
+			.type_desc = &tb_fw_hash,
+			.data = {
+				.ptr = (void *)tb_fw_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		},
+		[1] = {
+			.type_desc = &tb_fw_config_hash,
+			.data = {
+				.ptr = (void *)tb_fw_config_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		},
+		[2] = {
+			.type_desc = &hw_config_hash,
+			.data = {
+				.ptr = (void *)hw_config_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		}
+	}
+};
+
+#ifdef IMAGE_BL1
+static const auth_img_desc_t bl2_image = {
+	.img_id = BL2_IMAGE_ID,
+	.img_type = IMG_RAW,
+	.parent = &trusted_boot_fw_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &tb_fw_hash
+			}
+		}
+	}
+};
+#endif /* IMAGE_BL1 */
+
+/* HW Config */
+static const auth_img_desc_t hw_config = {
+	.img_id = HW_CONFIG_ID,
+	.img_type = IMG_RAW,
+	.parent = &trusted_boot_fw_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &hw_config_hash
+			}
+		}
+	}
+};
+
+/* TB FW Config */
+#ifdef IMAGE_BL1
+static const auth_img_desc_t tb_fw_config = {
+	.img_id = TB_FW_CONFIG_ID,
+	.img_type = IMG_RAW,
+	.parent = &trusted_boot_fw_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &tb_fw_config_hash
+			}
+		}
+	}
+};
+#endif /* IMAGE_BL1 */
+
+#ifdef IMAGE_BL2
+/* Trusted key certificate */
+static const auth_img_desc_t trusted_key_cert = {
+	.img_id = TRUSTED_KEY_CERT_ID,
+	.img_type = IMG_CERT,
+	.parent = NULL,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_SIG,
+			.param.sig = {
+				.pk = &subject_pk,
+				.sig = &sig,
+				.alg = &sig_alg,
+				.data = &raw_data
+			}
+		},
+		[1] = {
+			.type = AUTH_METHOD_NV_CTR,
+			.param.nv_ctr = {
+				.cert_nv_ctr = &trusted_nv_ctr,
+				.plat_nv_ctr = &trusted_nv_ctr
+			}
+		}
+	},
+	.authenticated_data = (const auth_param_desc_t[COT_MAX_VERIFIED_PARAMS]) {
+		[0] = {
+			.type_desc = &trusted_world_pk,
+			.data = {
+				.ptr = (void *)trusted_world_pk_buf,
+				.len = (unsigned int)PK_DER_LEN
+			}
+		},
+	}
+};
+
+/* SCP Firmware */
+static const auth_img_desc_t scp_fw_key_cert = {
+	.img_id = SCP_FW_KEY_CERT_ID,
+	.img_type = IMG_CERT,
+	.parent = &trusted_key_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_SIG,
+			.param.sig = {
+				.pk = &trusted_world_pk,
+				.sig = &sig,
+				.alg = &sig_alg,
+				.data = &raw_data
+			}
+		},
+		[1] = {
+			.type = AUTH_METHOD_NV_CTR,
+			.param.nv_ctr = {
+				.cert_nv_ctr = &trusted_nv_ctr,
+				.plat_nv_ctr = &trusted_nv_ctr
+			}
+		}
+	},
+	.authenticated_data = (const auth_param_desc_t[COT_MAX_VERIFIED_PARAMS]) {
+		[0] = {
+			.type_desc = &scp_fw_content_pk,
+			.data = {
+				.ptr = (void *)content_pk_buf,
+				.len = (unsigned int)PK_DER_LEN
+			}
+		}
+	}
+};
+
+static const auth_img_desc_t scp_fw_content_cert = {
+	.img_id = SCP_FW_CONTENT_CERT_ID,
+	.img_type = IMG_CERT,
+	.parent = &scp_fw_key_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_SIG,
+			.param.sig = {
+				.pk = &scp_fw_content_pk,
+				.sig = &sig,
+				.alg = &sig_alg,
+				.data = &raw_data
+			}
+		},
+		[1] = {
+			.type = AUTH_METHOD_NV_CTR,
+			.param.nv_ctr = {
+				.cert_nv_ctr = &trusted_nv_ctr,
+				.plat_nv_ctr = &trusted_nv_ctr
+			}
+		}
+	},
+	.authenticated_data = (const auth_param_desc_t[COT_MAX_VERIFIED_PARAMS]) {
+		[0] = {
+			.type_desc = &scp_fw_hash,
+			.data = {
+				.ptr = (void *)scp_fw_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		}
+	}
+};
+
+static const auth_img_desc_t scp_bl2_image = {
+	.img_id = SCP_BL2_IMAGE_ID,
+	.img_type = IMG_RAW,
+	.parent = &scp_fw_content_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &scp_fw_hash
+			}
+		}
+	}
+};
+
+/* SoC Firmware */
+static const auth_img_desc_t soc_fw_key_cert = {
+	.img_id = SOC_FW_KEY_CERT_ID,
+	.img_type = IMG_CERT,
+	.parent = &trusted_key_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_SIG,
+			.param.sig = {
+				.pk = &trusted_world_pk,
+				.sig = &sig,
+				.alg = &sig_alg,
+				.data = &raw_data
+			}
+		},
+		[1] = {
+			.type = AUTH_METHOD_NV_CTR,
+			.param.nv_ctr = {
+				.cert_nv_ctr = &trusted_nv_ctr,
+				.plat_nv_ctr = &trusted_nv_ctr
+			}
+		}
+	},
+	.authenticated_data = (const auth_param_desc_t[COT_MAX_VERIFIED_PARAMS]) {
+		[0] = {
+			.type_desc = &soc_fw_content_pk,
+			.data = {
+				.ptr = (void *)content_pk_buf,
+				.len = (unsigned int)PK_DER_LEN
+			}
+		}
+	}
+};
+
+static const auth_img_desc_t soc_fw_content_cert = {
+	.img_id = SOC_FW_CONTENT_CERT_ID,
+	.img_type = IMG_CERT,
+	.parent = &soc_fw_key_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_SIG,
+			.param.sig = {
+				.pk = &soc_fw_content_pk,
+				.sig = &sig,
+				.alg = &sig_alg,
+				.data = &raw_data
+			}
+		},
+		[1] = {
+			.type = AUTH_METHOD_NV_CTR,
+			.param.nv_ctr = {
+				.cert_nv_ctr = &trusted_nv_ctr,
+				.plat_nv_ctr = &trusted_nv_ctr
+			}
+		}
+	},
+	.authenticated_data = (const auth_param_desc_t[COT_MAX_VERIFIED_PARAMS]) {
+		[0] = {
+			.type_desc = &soc_fw_hash,
+			.data = {
+				.ptr = (void *)soc_fw_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		},
+		[1] = {
+			.type_desc = &soc_fw_config_hash,
+			.data = {
+				.ptr = (void *)soc_fw_config_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		}
+	}
+};
+
+static const auth_img_desc_t bl31_image = {
+	.img_id = BL31_IMAGE_ID,
+	.img_type = IMG_RAW,
+	.parent = &soc_fw_content_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &soc_fw_hash
+			}
+		}
+	}
+};
+
+/* SOC FW Config */
+static const auth_img_desc_t soc_fw_config = {
+	.img_id = SOC_FW_CONFIG_ID,
+	.img_type = IMG_RAW,
+	.parent = &soc_fw_content_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &soc_fw_config_hash
+			}
+		}
+	}
+};
+
+/* Trusted OS Firmware */
+static const auth_img_desc_t trusted_os_fw_key_cert = {
+	.img_id = TRUSTED_OS_FW_KEY_CERT_ID,
+	.img_type = IMG_CERT,
+	.parent = &trusted_key_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_SIG,
+			.param.sig = {
+				.pk = &trusted_world_pk,
+				.sig = &sig,
+				.alg = &sig_alg,
+				.data = &raw_data
+			}
+		},
+		[1] = {
+			.type = AUTH_METHOD_NV_CTR,
+			.param.nv_ctr = {
+				.cert_nv_ctr = &trusted_nv_ctr,
+				.plat_nv_ctr = &trusted_nv_ctr
+			}
+		}
+	},
+	.authenticated_data = (const auth_param_desc_t[COT_MAX_VERIFIED_PARAMS]) {
+		[0] = {
+			.type_desc = &tos_fw_content_pk,
+			.data = {
+				.ptr = (void *)content_pk_buf,
+				.len = (unsigned int)PK_DER_LEN
+			}
+		}
+	}
+};
+
+static const auth_img_desc_t trusted_os_fw_content_cert = {
+	.img_id = TRUSTED_OS_FW_CONTENT_CERT_ID,
+	.img_type = IMG_CERT,
+	.parent = &trusted_os_fw_key_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_SIG,
+			.param.sig = {
+				.pk = &tos_fw_content_pk,
+				.sig = &sig,
+				.alg = &sig_alg,
+				.data = &raw_data
+			}
+		},
+		[1] = {
+			.type = AUTH_METHOD_NV_CTR,
+			.param.nv_ctr = {
+				.cert_nv_ctr = &trusted_nv_ctr,
+				.plat_nv_ctr = &trusted_nv_ctr
+			}
+		}
+	},
+	.authenticated_data = (const auth_param_desc_t[COT_MAX_VERIFIED_PARAMS]) {
+		[0] = {
+			.type_desc = &tos_fw_hash,
+			.data = {
+				.ptr = (void *)tos_fw_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		},
+		[1] = {
+			.type_desc = &tos_fw_extra1_hash,
+			.data = {
+				.ptr = (void *)tos_fw_extra1_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		},
+		[2] = {
+			.type_desc = &tos_fw_extra2_hash,
+			.data = {
+				.ptr = (void *)tos_fw_extra2_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		},
+		[3] = {
+			.type_desc = &tos_fw_config_hash,
+			.data = {
+				.ptr = (void *)tos_fw_config_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		}
+	}
+};
+
+static const auth_img_desc_t bl32_image = {
+	.img_id = BL32_IMAGE_ID,
+	.img_type = IMG_RAW,
+	.parent = &trusted_os_fw_content_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &tos_fw_hash
+			}
+		}
+	}
+};
+
+static const auth_img_desc_t bl32_extra1_image = {
+	.img_id = BL32_EXTRA1_IMAGE_ID,
+	.img_type = IMG_RAW,
+	.parent = &trusted_os_fw_content_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &tos_fw_extra1_hash
+			}
+		}
+	}
+};
+
+static const auth_img_desc_t bl32_extra2_image = {
+	.img_id = BL32_EXTRA2_IMAGE_ID,
+	.img_type = IMG_RAW,
+	.parent = &trusted_os_fw_content_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &tos_fw_extra2_hash
+			}
+		}
+	}
+};
+
+/* TOS FW Config */
+static const auth_img_desc_t tos_fw_config = {
+	.img_id = TOS_FW_CONFIG_ID,
+	.img_type = IMG_RAW,
+	.parent = &trusted_os_fw_content_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &tos_fw_config_hash
+			}
+		}
+	}
+};
+
+/* Non-Trusted Firmware */
+static const auth_img_desc_t non_trusted_fw_content_cert = {
+	.img_id = NON_TRUSTED_FW_CONTENT_CERT_ID,
+	.img_type = IMG_CERT,
+	.parent = NULL, /* Root certificate.  */
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_SIG,
+			.param.sig = {
+				.pk = &prot_pk,
+				.sig = &sig,
+				.alg = &sig_alg,
+				.data = &raw_data
+			}
+		},
+		[1] = {
+			.type = AUTH_METHOD_NV_CTR,
+			.param.nv_ctr = {
+				.cert_nv_ctr = &non_trusted_nv_ctr,
+				.plat_nv_ctr = &non_trusted_nv_ctr
+			}
+		}
+	},
+	.authenticated_data = (const auth_param_desc_t[COT_MAX_VERIFIED_PARAMS]) {
+		[0] = {
+			.type_desc = &nt_world_bl_hash,
+			.data = {
+				.ptr = (void *)nt_world_bl_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		},
+		[1] = {
+			.type_desc = &nt_fw_config_hash,
+			.data = {
+				.ptr = (void *)nt_fw_config_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		}
+	}
+};
+
+static const auth_img_desc_t bl33_image = {
+	.img_id = BL33_IMAGE_ID,
+	.img_type = IMG_RAW,
+	.parent = &non_trusted_fw_content_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &nt_world_bl_hash
+			}
+		}
+	}
+};
+
+/* NT FW Config */
+static const auth_img_desc_t nt_fw_config = {
+	.img_id = NT_FW_CONFIG_ID,
+	.img_type = IMG_RAW,
+	.parent = &non_trusted_fw_content_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &nt_fw_config_hash
+			}
+		}
+	}
+};
+
+#else  /* IMAGE_BL2 */
+
+/* FWU auth descriptor */
+static const auth_img_desc_t fwu_cert = {
+	.img_id = FWU_CERT_ID,
+	.img_type = IMG_CERT,
+	.parent = NULL,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_SIG,
+			.param.sig = {
+				.pk = &subject_pk,
+				.sig = &sig,
+				.alg = &sig_alg,
+				.data = &raw_data
+			}
+		}
+	},
+	.authenticated_data = (const auth_param_desc_t[COT_MAX_VERIFIED_PARAMS]) {
+		[0] = {
+			.type_desc = &scp_bl2u_hash,
+			.data = {
+				.ptr = (void *)scp_fw_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		},
+		[1] = {
+			.type_desc = &bl2u_hash,
+			.data = {
+				.ptr = (void *)tb_fw_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		},
+		[2] = {
+			.type_desc = &ns_bl2u_hash,
+			.data = {
+				.ptr = (void *)nt_world_bl_hash_buf,
+				.len = (unsigned int)HASH_DER_LEN
+			}
+		}
+	}
+};
+
+/* SCP_BL2U */
+static const auth_img_desc_t scp_bl2u_image = {
+	.img_id = SCP_BL2U_IMAGE_ID,
+	.img_type = IMG_RAW,
+	.parent = &fwu_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &scp_bl2u_hash
+			}
+		}
+	}
+};
+
+/* BL2U */
+static const auth_img_desc_t bl2u_image = {
+	.img_id = BL2U_IMAGE_ID,
+	.img_type = IMG_RAW,
+	.parent = &fwu_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &bl2u_hash
+			}
+		}
+	}
+};
+
+/* NS_BL2U */
+static const auth_img_desc_t ns_bl2u_image = {
+	.img_id = NS_BL2U_IMAGE_ID,
+	.img_type = IMG_RAW,
+	.parent = &fwu_cert,
+	.img_auth_methods = (const auth_method_desc_t[AUTH_METHOD_NUM]) {
+		[0] = {
+			.type = AUTH_METHOD_HASH,
+			.param.hash = {
+				.data = &raw_data,
+				.hash = &ns_bl2u_hash
+			}
+		}
+	}
+};
+#endif /* IMAGE_BL2 */
+
+/*
+ * Chain of trust definition
+ */
+#ifdef IMAGE_BL1
+static const auth_img_desc_t * const cot_desc[] = {
+	[TRUSTED_BOOT_FW_CERT_ID]		=	&trusted_boot_fw_cert,
+	[BL2_IMAGE_ID]				=	&bl2_image,
+	[HW_CONFIG_ID]				=	&hw_config,
+	[TB_FW_CONFIG_ID]			=	&tb_fw_config,
+	[FWU_CERT_ID]				=	&fwu_cert,
+	[SCP_BL2U_IMAGE_ID]			=	&scp_bl2u_image,
+	[BL2U_IMAGE_ID]				=	&bl2u_image,
+	[NS_BL2U_IMAGE_ID]			=	&ns_bl2u_image
+};
+#else /* IMAGE_BL2 */
+static const auth_img_desc_t * const cot_desc[] = {
+	[TRUSTED_BOOT_FW_CERT_ID]		=	&trusted_boot_fw_cert,
+	[HW_CONFIG_ID]				=	&hw_config,
+	[TRUSTED_KEY_CERT_ID]			=	&trusted_key_cert,
+	[SCP_FW_KEY_CERT_ID]			=	&scp_fw_key_cert,
+	[SCP_FW_CONTENT_CERT_ID]		=	&scp_fw_content_cert,
+	[SCP_BL2_IMAGE_ID]			=	&scp_bl2_image,
+	[SOC_FW_KEY_CERT_ID]			=	&soc_fw_key_cert,
+	[SOC_FW_CONTENT_CERT_ID]		=	&soc_fw_content_cert,
+	[BL31_IMAGE_ID]				=	&bl31_image,
+	[SOC_FW_CONFIG_ID]			=	&soc_fw_config,
+	[TRUSTED_OS_FW_KEY_CERT_ID]		=	&trusted_os_fw_key_cert,
+	[TRUSTED_OS_FW_CONTENT_CERT_ID]		=	&trusted_os_fw_content_cert,
+	[BL32_IMAGE_ID]				=	&bl32_image,
+	[BL32_EXTRA1_IMAGE_ID]			=	&bl32_extra1_image,
+	[BL32_EXTRA2_IMAGE_ID]			=	&bl32_extra2_image,
+	[TOS_FW_CONFIG_ID]			=	&tos_fw_config,
+	[NON_TRUSTED_FW_CONTENT_CERT_ID]	=	&non_trusted_fw_content_cert,
+	[BL33_IMAGE_ID]				=	&bl33_image,
+	[NT_FW_CONFIG_ID]			=	&nt_fw_config,
+};
+#endif
+
+/* Register the CoT in the authentication module */
+REGISTER_COT(cot_desc);
diff --git a/include/tools_share/dualroot_oid.h b/include/tools_share/dualroot_oid.h
new file mode 100644
index 0000000..3e88a6d
--- /dev/null
+++ b/include/tools_share/dualroot_oid.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef DUALROOT_OID_H
+#define DUALROOT_OID_H
+
+/* Reuse the Object IDs defined by TBBR for certificate extensions. */
+#include "tbbr_oid.h"
+
+/*
+ * Platform root-of-trust public key.
+ * Arbitrary value that does not conflict with any of the TBBR reserved OIDs.
+ */
+#define PROT_PK_OID				"1.3.6.1.4.1.4128.2100.1102"
+
+#endif /* DUALROOT_OID_H */